論文 - 山崎　慎一

Effect of the blend ratio of cyclic and linear polyethylene blends on isothermal crystallization in the quiescent state 査読

Keiko Kobayashi, Hironori Atarashi, Shinichi Yamazaki, Kunio Kimura

Polymer Journal   55 ( 12 )   1393 - 1398   2023年8月

　詳細を見る

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41428-023-00833-1

researchmap

その他リンク： https://www.nature.com/articles/s41428-023-00833-1

Role of entanglement species in the formation of shish-like fibril crystals elucidated by cyclic polyethylene 査読

Keiko Kobayashi, Yuya Saito, Shinichi Yamazaki, Kunio Kimura

Journal of Fiber Science and Technology   79 ( 8 )   177 - 184   2023年8月

　詳細を見る

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2115/fiberst.2023-0011

researchmap

Influence of Preparation Conditions on Porosity of Aromatic Polyamide Hollow Spheres 査読

Hirofumi Nakayama, Naoto Kibayashi, Hironori Atarashi, Shinichi Yamazaki, Kunio Kimura

Journal of Fiber Science and Technology   79 ( 8 )   185 - 191   2023年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Society of Fiber Science and Technology Japan  

DOI： 10.2115/fiberst.2023-0017

researchmap

Formation of shish-like fibril crystals from the melt of blends of cyclic and linear polyethylene under shear flow 査読

Keiko Kobayashi, Shinichi Yamazaki, Kunio Kimura

Polymer Journal   54 ( 7 )   913 - 920   2022年4月

　詳細を見る

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41428-022-00643-x

researchmap

その他リンク： https://www.nature.com/articles/s41428-022-00643-x

Morphology and growth rate of spherulite of cyclic poly(ε-caprolactone) having a triazole group at the closing point 査読

Atsushi Shinya, Ryogo Ono, Hironori Atarashi, Shinichi Yamazaki, Kunio Kimura

Polymer   202   122660 - 122660   2020年5月

　詳細を見る

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.polymer.2020.122660

Web of Science

researchmap

Molecular weight dependence of the growth rate of spherulite of cyclic poly(ε-caprolactone) polymerized by ring expansion reaction 査読

Ryogo Ono, Hironori Atarashi, Shinichi Yamazaki, Kunio Kimura

Polymer   194   122403 - 122403   2020年4月

　詳細を見る

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.polymer.2020.122403

Web of Science

researchmap

Microspheres with dimple morphology of poly(p-oxyferuloyl) prepared by reaction-induced phase separation

Hironori Atarashi, Masahaya Sugimoto, Shinichi Yamazaki, Kunio Kimura

Fiber Society 2018 Spring Conference: Fibers and Textiles for Value Creation in Connected Industries   2018年

　詳細を見る

掲載種別：研究論文（国際会議プロシーディングス）  

Scopus

researchmap

Size control of aromatic polyamide hollow spheres prepared by reaction-induced phase separation 査読

Hirofumi Nakayama, Naoto Adachi, Hironori Atarashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

POLYMER   111   239 - 243   2017年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Size control of the poly (1,4-phenylene-5-hydroxyisophthalamide) hollow spheres was examined by tuning the polymerization condition, focusing on concentration, temperature and solvent. Higher concentration lowered the diameter owing to the higher degree of super-saturation for nucleation. Temperature drop during the polymerization just before the nucleation was so effective to make the diameter smaller. Moreover, the diameter was susceptive to the solubility of oligomers in the solvent, and higher content of liquid paraffin in the aromatic solvent lowered the solubility, resulting in the decrease in the diameter. Based on these results, the combination of the temperature drop and the solvent effect was the most desirable to prepare the smallest hollow spheres, and the diameter of hollow spheres could be controlled from 4.4 to 0.7 mu m. (C) 2017 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2017.01.060

Web of Science

researchmap

Preparation of aromatic polyimide particles having clear morphology by polymerization of salt monomers 査読

Daisaku Shojo, Hidekazu Sugimori, Shinichi Yamazaki, Kunio Kimura

HIGH PERFORMANCE POLYMERS   28 ( 10 )   1139 - 1150   2016年12月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SAGE PUBLICATIONS LTD  

Crystals of salt monomer prepared from aromatic tetracarboxylic acids and aromatic diamines were polymerized at 220 degrees C for 3 h and at 400 degrees C for 3 h under argon flow. Highly crystalline polyimide particles having clear morphology were obtained with good yield. They were lozenge-like crystals, long plate-like crystals, fibrillar crystals, and spherical aggregates of plate-like crystals. The crystals of salt monomer were polymerized in the solid-state with maintaining the morphology, and therefore the morphology of the polyimide particles were the same to that of the crystals of the corresponding salt monomer. Molecular orientation in the lozenge-shaped crystal of poly(p-phenylene pyromelliteimide) was examined by selected area electron diffraction, and the polymer molecules aligned perpendicular to the plate plane which was the direction of the thickness. Obtained particles possessed good thermal stability.

DOI： 10.1177/0954008315619998

Web of Science

researchmap

Preparation of poly(ether ketone)s derived from 2,5-furandicarboxylic acid via nucleophilic aromatic substitution polymerization 査読

Yusuke Kanetaka, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   54 ( 19 )   3094 - 3101   2016年10月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

From the viewpoint of the suppression of the petroleum consumption, aromatic poly(ether ketone)s (PEKs) were prepared by the nucleophilic aromatic substitution polymerization of 2,5-bis(4-fluorobenzoyl)furan (BFBF) synthesized from biomass and aromatic bisphenols. The model reaction of BFBF and p-methoxyphenol revealed that BFBF possessed enough reactivity for the nucleophilic aromatic substitution reactions. The polymerizations of BFBF and aromatic bisphenols afforded high molecular weight polymers with good yields in N-methylpyrrolidone and diphenyl sulfone for several hours. The longer polymerization time brought about the formation of insoluble parts in any solvents and reduction of molecular weight. The obtained PEKs were thermoplastics and exhibited good thermal stability, mechanical properties, and chemical resistance comparable to common high-performance polymers. The thermal properties were tunable with the structure of bisphenols. (c) 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3094-3101

DOI： 10.1002/pola.28193

Web of Science

researchmap

Preparation of helical crystals of aromatic poly(ester-imide) and on-off switching of helix formation 査読

Takuya Ohnishi, Miki Nakagawa, Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

POLYMER   98   378 - 386   2016年8月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Preparation of poly[4-(5-oxy-1,3-dioxoisoindoline-2-yl)benzoyl] (PODB) crystals, which was an intractable aromatic poly(ester-imide), was examined by means of reaction-induced crystallization of oligomers during the polymerization. Highly crystalline PODB helical ribbons were obtained by the polymerization of N-(4-carboxyphenyl)-4-acetoxyphthalimide in aromatic solvent at 280-330 degrees C at a concentration of 0.5-1.0%. The PODB molecules aligned along the long axis of the helical ribbon. The pitch of the helix increased with the polymerization temperature and it could be controlled from 320 nm to 1.3 mu m. Further, the fibrillar PODB crystals comprised of the helical and the non-helical blocks were prepared by the on-off switching of the helical morphology with the changing the temperature and the concentration of the polymerization. These results provided the methodology for the morphology control of polymer crystals. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2016.06.055

Web of Science

researchmap

Preparation of Poly(ether ketone)s Derived from 2,5-Furandicarboxylic Acid by Polymerization in Ionic Liquid 査読

Yusuke Kanetaka, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULES   49 ( 4 )   1252 - 1258   2016年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

Aromatic poly(ether ketone)s were synthesized by the Friedel Crafts polymerization of 2,5-furandicarbonyl dichloride prepared from biomass and petroleum-based aromatic ethers such as diphenyl ether and 1,4-diphenoxybenzene with aluminum chloride (AlCl3). The polymerizations in common molecular solvents such as 1,2-dichloroethane and nitrobenzene did not afford polymers. The Friedel-Crafts polymerization usually undergoes in the swollen gel of the oligomer-AlCl3 complexes; the precipitated physical gels had not been enough swollen. The polymerizations were carried out in various ionic liquids to form swollen gels. The polymerizations proceeded in specific ionic liquid such as 1-butyl-3-methylimidazolium chloride ([C(4)min] CO, and high molecular weight polymers were obtained with good yield. The gels formed in [C(4)mim] Cl were more highly swollen, and additionally the rate constant estimated by the model reaction of 2,5-furandicarbonyl dichloride and anisole was higher in [C4(m)im]Cl than that in 1,2-dichloroethane. The obtained poly(ether ketone)s exhibited good thermal stability and chemical resistance comparable to common poly(ether ketone)s.

DOI： 10.1021/acs.macromol.5b02788

Web of Science

researchmap

One-Pot Preparation of Aromatic Poly(ester-imide) Crystals by Crystallization during Polymerization 査読

Takuya Ohnishi, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF FIBER SCIENCE AND TECHNOLOGY   72 ( 2 )   49 - 53   2016年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC FIBER SCIENCE TECHNOLOGY  

One-pot preparation of poly[ 4-(5-oxy-1,3-dioxoisoindolin-2-yl) benzoyl] (PODB) crystals which was an aromatic poly(ester-imide) was examined by means of the reaction-induced crystallization during polymerization of 4-acetoxyphthalic anhydride (APA) and 4-aminobenzoic acid (AmBA). Two-step heating program was suitable for the formation of PODB crystals. The reaction of APA and AmBA at 150 degrees C, which was much lower than the polymerization temperature, was of importance to synthesize N-(4-carboxyphenyl)-4-acetoxyphthalimide. Even though the amide moiety was incorporated, the PODB crystals were formed as precipitates by heating at 150 degrees C and then at 280-350 degrees C. Morphology of PODB depended on the polymerization conditions and fibrillar crystals, rod-like crystals and ribbon-like crystals were obtained. This result provided a novel one-pot procedure for the control of the PODB morphology.

DOI： 10.2115/fiberst.2016-0008

Web of Science

researchmap

High Performance Polyesters Prepared from Bio-Based 2,5-Furandicarboxylic Acid 査読

Yusuke Kanetaka, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF FIBER SCIENCE AND TECHNOLOGY   72 ( 2 )   54 - 60   2016年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC FIBER SCIENCE TECHNOLOGY  

Aromatic polyesters were synthesized by the polymerization of bio-based 2,5-furandicarboxylic acid (FDCA) with petroleum-based 1,3-and 1,4-diacetoxybenzene (DAB) from the viewpoint of the suppression of the petroleum consumption to develop the sustainable development society. Polyesters prepared at the molar ratio of 1,4-DAB in DAB (chi) of less than 60 mol% showed meltability under decomposition temperature. When the value of chi was 20-60 mol%, the polyesters exhibited optical anisotropicity in melt phase, suggesting the thermotropic liquid crystallinity. The phase transition temperature of these polyesters depended on the composition and it was tunable by the. value. The film of the polyesters prepared at. of 20 mol% possessed 1.2 GPa of the modulus, 26.0 MPa and 2.9% of the strength and elongation at break, respectively. Polyesters based on FDCA possessed good thermal stability and mechanical properties comparable to common aromatic polyesters.

DOI： 10.2115/fiberst.2016-0009

Web of Science

researchmap

Synthesis of Poly(ether ketone)s from 2,5-Thiophenedicarboxylic Acid 査読

Yusuke Kanetaka, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   29 ( 2 )   243 - 246   2016年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TECHNICAL ASSOC PHOTOPOLYMERS,JAPAN  

The Friedel-Crafts polymerization of 2,5-thiophenedicarbonyl dichloride and diphenyl ether in 1,2-dichloroethane afforded only low molecular weight of poly(ether ketone) containing thiophene-ring. In contrast to this, the polymerization in 1-butyl-3-methylimidazolium chloride-aluminum chloride mixture gave high molecular weight polymers. The polymerizations in ionic liquids were a new approach to expand possibility of polymer synthesis such as preparation of polymer containing heterocyclic rings. The obtained poly(ether ketone) exhibited good thermal stability and chemical resistance comparable to common poly(ether ketone)s.

DOI： 10.2494/photopolymer.29.243

Web of Science

researchmap

Preparation of poly(ester-imide) ribbons comprised of helical and non-helical blocks by copolymerization 査読

T. Ohnishi, T. Uchida, S. Yamazaki, K. Kimura

RSC ADVANCES   6 ( 104 )   101995 - 102002   2016年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC CHEMISTRY  

Helical ribbons of poly[4-(5-oxy-1,3-dioxoisoindoline-2-yl) benzoyl] (PODB) were previously prepared by the homo-polymerization of N-(4-carboxyphenyl)-4-acetoxyphthalimide (CAP) in aromatic solvents. The copolymerization of CAP and p-acetoxybenzoic acid (ABA) was examined to change the helical morphology. The helical morphology was extinguished by the copolymerization of a small amount of ABA at 280 degrees C at a concentration of 1.0% in aromatic solvent. Based on these results, ABA was added stepwise during the homo-polymerization of CAP. When a small amount of ABA was added, copolymer crystals comprised of helical and non-helical blocks were formed. The non-helical blocks grew on the PODB helical ribbons by the precipitation of co-oligomers. This result provides a novel method to control helical morphology by copolymerization.

DOI： 10.1039/c6ra22494f

Web of Science

researchmap

Hydrothermal synthesis of aromatic polyimide particles by using reaction-induced crystallization 査読

Daisaku Shojo, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   53 ( 24 )   2795 - 2799   2015年12月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

DOI： 10.1002/pola.27791

Web of Science

researchmap

Consideration on formation mechanism of aromatic polyamide hollow spheres prepared by reaction-Induced phase separation 査読

Hirofumi Nakayama, Yuji Fujitsu, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   53 ( 17 )   1966 - 1974   2015年9月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Hollow spheres of poly(1,4-phenylene-5-hydroxyisophthalamide) had been obtained by the reaction-induced phase separation during polymerization of 5-hydroxyisophthalic acid and 1,4-phenylene diamine in an aromatic solvent. In this study, formation mechanism of the hollow spheres was considered from the view points of eliminated small molecules, polymer structure, and cross-linking reaction. With respect to the eliminated small molecules, water was the most desirable to form gas-bubbles in droplets compared with methanol and acetic acid, due to the insolubility into the polymerization system. Rigid polymer structure was also needed to prepare hollow spheres owing to the rapid solidification of droplets. Further, phenolic hydroxyl group in 5-hydroxy-1,3-phenylene moiety caused the ester-amide exchange reaction to form cross-linked skin layer in the droplets. The efficient formation of the skin layer was important to encapsulate gas-bubbles in the droplets, resulting in the formation of hollow structure. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1966-1974

DOI： 10.1002/pola.27683

Web of Science

researchmap

Preparation of aromatic polyesters by direct polymerization in the presence of boronic anhydride under non-stoichiometric condition 査読

Masahiro Kihara, Yuma Sakakiyama, Shinichi Yamazaki, Kunio Kimura

POLYMER   66   222 - 229   2015年6月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Direct polymerizations of p-hydroxybenzoic acid (HBA) and 2-hydroxy-6-naphthoic acid (HNA) in the presence of boronic anhydride were examined by using crystallization under non-stoichiometric condition. The polymerizations were carried out with the addition of monofunctional compounds such as an aromatic carboxylic acid and a phenol. High molecular weight poly(p-oxybenzoyl) (PUB) and poly(2-oxy-6-naphthoyl) (PUN) were obtained in the form of precipitates, and their molecular weights were much higher than those calculated according to the stoichiometric imbalance. Oligomers were formed by the direct polymerization with eliminating water in the solution, and then they were precipitated to form the crystals at the initial stage of the polymerization. Oligomers end-capped by monofunctional compounds were also formed in the solution, but the polymerization continued with the elimination of monofunctional compounds by the ester exchange reaction. The end-capped oligomers were precipitated in the middle of the polymerization, and the polymerization proceeded efficiently even in the precipitated crystals by not only the direct polymerization but also the ester exchange polymerization, resulting in the increase in molecular weight. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2015.04.019

Web of Science

researchmap

バイオベーススーパーエンジニアリングプラスチック : フランジカルボン酸を原料とした芳香族ポリエーテルケトンの合成

兼高 悠輔, 山崎 慎一, 木村 邦生

プラスチックス : 日本プラスチック工業連盟誌   65 ( 7 )   62 - 66   2014年7月

　詳細を見る

記述言語：日本語   出版者・発行元：日本工業出版  

CiNii Article

CiNii Books

researchmap

バイオマスを原料としたスーパーエンプラの調製 招待

木村邦生, 山崎慎一, 兼高悠輔

ケミカルエンジニヤリング   59 ( 6 )   39 - 43   2014年6月

　詳細を見る

記述言語：日本語  

researchmap

マテリアルニュース&トピックス バイオ材料由来の「スーパーエンジニアリングプラスチック」の開発

兼高 悠輔, 山崎 慎一, 木村 邦生

Material stage   14 ( 1 )   47 - 51   2014年4月

　詳細を見る

記述言語：日本語   出版者・発行元：技術情報協会  

CiNii Article

researchmap

バイオマスから作るスーパーエンプラ 招待

兼高悠輔, 山崎慎一, 木村邦生

コンバーテック   42 ( 2 )   48 - 52   2014年2月

　詳細を見る

記述言語：日本語  

researchmap

多重水素結合性官能基を末端に有するポリエチレンおよびポリジオキサノンの結晶化 査読

内村 美香, 岡崎 康平, 山崎 慎一, 木村 邦生

高分子論文集   71 ( 11 )   562 - 572   2014年

　詳細を見る

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/koron.71.562

Web of Science

researchmap

アラミドの中空微粒子の新調製法 招待

木村邦生, 山崎慎一, 内田哲也, 中山博文

ケミカルエンジニヤリング   59 ( 12 )   1 - 5   2014年

　詳細を見る

記述言語：日本語  

researchmap

Heterogeneous Polycondensation for Composition Control of Poly(p-mercaptobenzoyl-co-p-benzamide) by Shearing 査読

Toshimitsu Ichimori, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   51 ( 20 )   4301 - 4308   2013年10月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Composition control of aromatic poly(thioester-amide) was examined by the reaction-induced phase separation during polymerization of S-acetyl-4-mercaptobenzoic acid (AMBA) and p-acetylaminobenzoic acid (AABA) in aromatic solvent. The poly(thioester-amide)s were obtained as precipitates and their yields became lower at the middle range of the content of AMBA in feed ((f)). The contents of p-mercaptobenzoyl (MB) moiety ((p)) in the precipitates prepared without shearing were in good agreement with the (f) values. In contrast to this, the (p) values of the precipitates prepared at (f) of 50-70 mol % under shearing were much lower than the (f) values. The reaction rate of AMBA increased with shearing, whereas that of AABA was unchanged by shearing. This shearing effect on the reaction rates accelerated to form the homo-oligomers. The solubility of MB oligomers enhanced by shearing, whereas that of p-benzamide oligomers did not enhance owing to the strong interaction through hydrogen bonding. The MB oligomers were inhibited to be precipitated, resulting in the lower (p) values than the (f) values. The composition could be controlled by the application of the shearing to the heterogeneous polymerization. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4301-4308

DOI： 10.1002/pola.26839

Web of Science

researchmap

Synthesis and morphology control of self-condensable naphthalene-containing polyimide by using reaction-induced crystallization 査読

Takashi Sawai, Kanji Wakabayashi, Shinichi Yamazaki, Tetsuya Uchida, Yoshimitsu Sakaguchi, Ryouhei Yamane, Kunio Kimura

European Polymer Journal   49 ( 8 )   2334 - 2343   2013年8月

　詳細を見る

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Poly(2,6-1H-benzo[f]isoindole-1,3(2H)-dione) (PBID), which was a self-condensable naphthalene-containing polyimide, was synthesized as precipitated crystals from 6-amino-3-(ethoxycarbonyl)-2-naphthoic acid and 7-amino-3-(ethoxycarbonyl)-2-naphthoic acid by using reaction-induced crystallization during solution polymerization. The obtained PBID crystals possessed high crystallinity, excellent thermal stability and chemical resistance. They neither exhibited Tg nor Tm under the decomposition temperature. The morphology of the PBID crystals depended on not only the polymerization conditions but also the isomeric structure of the monomer, and the wide variety of the morphology appeared such as rods, plates and lathes. The plate-like crystals had fine protuberances on the surface. Copolymerization of PBID and poly(4-phthalimide) were also examined. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.eurpolymj.2013.05.021

Scopus

researchmap

Morphological diversity and nanofiber networks of poly(p-oxybenzoyl) generated by phase separation during copolymerization 査読

Toshimitsu Ichimori, Kenta Mizuma, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

Journal of Applied Polymer Science   128 ( 2 )   1282 - 1290   2013年4月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Poly(p-oxybenzoyl) (POB) precipitates prepared by reaction-induced phase separation during copolymerization exhibit wide variety of morphologies such as fibril, needle, slab, spindle, and sphere. The morphology is significantly influenced by the copolymerization conditions of structure of trifunctional comonomers, copolymerization ratio, solvent, concentration, and temperature of the polymerization. Among them, POB nanofiber networks like a texture of nonwoven fabrics are obtained only by the polymerization of 4-acetoxybenzoic acid with 3,5-diacetoxybenzoic acid (DABA) in aromatic solvent at a concentration of 1.0-2.0% at the content of DABA in feed of 10-20 mol % at 320°C. The network is comprised of fibrillar crystals connected each other at spherical nodal points. The diameters of the fibers are 90-129 nm. This network is highly crystalline and the molecules are aligned along the long direction of the fibers. Various parameters characterized the networks can be controlled by the polymerization concentration. © 2012 Wiley Periodicals, Inc.

DOI： 10.1002/app.38554

Scopus

researchmap

Hollow Spheres of Aromatic Polyamide Prepared by Reaction-Induced Phase Separation 査読

Yuji Fujitsu, Hirofumi Nakayama, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   51 ( 4 )   780 - 785   2013年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Hollow spheres of aromatic polyamide are obtained by the reaction-induced phase separation during polymerization of 5-hydroxyisophthalic acid and 1,4-phenylene diamine in an aromatic solvent at a concentration of 1-2% at 320 degrees C without stirring. The hollow sphere has a dimple hole and the diameters of the hollow spheres are 3-4 mu m. The droplets are initially generated via liquid-liquid phase separation and then rigid crosslinked network structure formed the rigid skin layer on the surface of the droplets. The solidification of the droplets occurred owing to the further polymerization in them with maintaining the morphology to form the hollow spheres. The hollow spheres exhibit outstanding thermal stability. (C) 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 780-785

DOI： 10.1002/pola.26467

Web of Science

researchmap

Preparation of Novel Naphthalene Polyimide and Its Morphology 査読

Takashi Sawai, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   26 ( 3 )   341 - 344   2013年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TECHNICAL ASSOC PHOTOPOLYMERS,JAPAN  

DOI： 10.2494/photopolymer.26.341

Web of Science

researchmap

Morphosynthesis of poly(ether ketone) by reaction-induced crystallization during polymerization 査読

Kanji Wakabayashi, Naofumi Sumi, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

EUROPEAN POLYMER JOURNAL   48 ( 10 )   1787 - 1795   2012年10月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Morphology control of poly(ether ketone) (PEK) was examined by using the crystallization during the nucleophilic aromatic substitution reaction of potassium salt of 4-fluoro-4'-hydroxybenzophenone. Polymerizations were carried out at 290 degrees C. The PEK was obtained as precipitates and its morphology was highly influenced by the polymerization condition such as the solvent, the concentration and the polymerization time. High crystalline spindle-like crystals were obtained by the polymerization in diphenyl sulfone (DPS) at a concentration of 5.0% for 2 h with the yield of 86%. The average length and width were 1.4 mu m and 300 nm respectively, and the maximum thickness was 130 nm. The surface was not smooth and it was hilly. The spindle-like crystal was likely consisted of multilayered lamellae comprised of the microcrystallites. The molecules were oriented perpendicular to the lamella. The polymerization in DPS at a higher concentration of 10.0% afforded the networks of nanofibres, of which the diameter was 100-250 nm. The obtained PEK precipitates possessed excellent thermal properties. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.eurpolymj.2012.07.004

Web of Science

researchmap

Morphosynthesis of poly[4-(1,4-phenylene)oxyphthalimide] and copolymers prepared by reaction-induced crystallization during polymerization 査読

Takashi Sawai, Kanji Wakabayashi, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS   50 ( 18 )   1293 - 1303   2012年9月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Morphosynthesis of poly[4-(1,4-phenylene)oxyphthalimide] (POPI) and poly[4-(1,4-phenylene)oxyphthalimide-co-4-phthalimide] (POPI-PPI) was examined by using the crystallization during the polymerization. The POPI fibrillar crystals were obtained as precipitates with the formation of spherical aggregates of plate-like crystals. Some of the POPI fibrillar crystals were longer than 15 mu m. They possessed high crystallinity and the molecules aligned perpendicular to the long direction of the fibers. On the other hand, one-dimensional structures of POPI-PPI such as ribbon, cone, rod, and fiber were obtained as precipitates by the copolymerization. The copolymer molecules might align along the long direction of the cone-like crystals. The morphology of these poly(ether-imide)s could be controlled by not only the polymerization condition but also with the aid of copolymerization. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012

DOI： 10.1002/polb.23122

Web of Science

researchmap

Selective Synthesis of Poly(p-oxybenzoyl) by Fractional Polycondensation: Enhancement of Selectivity by Shearing 査読

Toshimitsu Ichimori, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   49 ( 21 )   4613 - 4617   2011年11月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

The influence of shear flow, especially the timing for the application of shearing, was examined to enhance the selectivity for the preparation of poly(p-oxybenzoyl) (Pp-OB) by using hydrodynamically induced phase separation during polymerization of 4-(4-acetoxybenzoyloxy) benzoic acid (p-ABAD) and m-acetoxybenzoic acid (m-ABA). The polymers containing few m-oxybenzoyl (m-OB) moieties were obtained as precipitates even at high content of m-OB moiety in feed (chi(f)) under shear flow. The content of m-OB moiety in the precipitates (chi(p)) prepared under shearing throughout the polymerization at the shear rate (gamma) of 489 s(-1) was 6.3 mol % even at chi(f) of 60 mol %. Especially, the Pp-OB was obtained as the precipitates at chi(f) of less than 50 mol %. The timing of the application of the shearing influenced the selectivity significantly, and the shearing just after the precipitation of the oligomers started was quite efficient to enhance the selectivity more. The chi(p) of the precipitates prepared with shearing at gamma of 489 s(-1) just after the precipitation was only 3.9 mol % even at chi(f) of 60 mol %. The shear flow reduced the difference in the reactivity between p-ABAD and m-ABA, resulting in the decrease in the selectivity with regard to the formation of p-oxybenzoyl homo-oligomer. However, the shear flow enhanced the difference in the miscibility between homo-oligomers and co-oligomers. This change in the miscibility by shear flow brought about the more rapid precipitation of homo-oligomers, leading to the enhancement of the selectivity. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 4613-4617, 2011

DOI： 10.1002/pola.24904

Web of Science

researchmap

環状ポリエチレンの球晶成長速度から探る高分子の結晶成長に及ぼすトポロジカルな拘束と結び目絡み合いの効果 査読

北原 綱樹, 山崎 慎一, 木村 邦生

高分子論文集   68 ( 10 )   694 - 701   2011年10月

　詳細を見る

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/koron.68.694

Web of Science

Scopus

researchmap

Morphology Control of Various Aromatic Polyimidazoles-Preparation of Nanofibers 査読

Jin Gong, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF APPLIED POLYMER SCIENCE   121 ( 5 )   2851 - 2860   2011年9月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Morphology of four kinds of aromatic polyimidazoles was examined by using reaction-induced crystallization during solution polymerization at a concentration of 1% at 350 degrees C in liquid paraffin (LPF), dibenzyltoluene (DBT), and the mixture of these solvents. Aggregates of ribbon-like crystals of poly[2,6-(2,6-naphthalene)-benzobisimidazole] were obtained in LPF, and those of plate-like crystals were obtained in DBT/LPF-50 and in DBT. In contrast to this, the network structures of poly[2,2'-(2,6-naphthalene)-5,5'-bibenzimidazole)] (PNT-BBI) nanofibers with the diameter of 25 to 90 nm was mainly obtained in DBT. The network structures of the PNT-BBI nanofibers could be recognized as nonwoven fabrics of the high-performance polymers. Imidazole trimers were precipitated to form the ribbon-like crystals and then they were continuously supplied from solution to grow the crystals. Molecular weight increased by the polymerization on the surface of the crystals when they crystallized and in the crystals. The initially formed aggregates of ribbon-like crystals changed to the nanofibers with time. In the case of poly[2,6-(4,4'-biphenylene)-benzobisimidazole] and poly[2,2'-(4,4'-biphenylene)-5,5'-bibenzimidazole)], they exhibited various morphologies such as spheres, lath-like crystals, and the spherical aggregates of lath-like crystals depending on the solvent, but fibers like PNT-BBI were not formed. The crystals obtained in this study possessed very high crystallinity and the outstanding thermal stability measured by TGA. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 2851-2860, 2011

DOI： 10.1002/app.33914

Web of Science

researchmap

Preparation of Poly(p-oxybenzoyl) Crystals Using Direct Polymerization of p-Hydroxybenzoic Acid in the Presence of Boronic Anhydrides 査読

Masahiro Kihara, Shin-Ichiro Kohama, Shota Umezono, Kanji Wakabayashi, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   49 ( 5 )   1088 - 1096   2011年3月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

Poly(p-oxybenzoyl) (POB) crystals were prepared by reaction-induced crystallization during direct polymerization of p-hydroxybenzoic acid in the presence of boronic anhydrides. Polymerizations were carried out at 300 degrees C in dibenzyltoluene at a concentration of 1% with three kinds of anhydrides of boronic acid such as 3,4,5-trifluorophenylboronic acid (TFB), 4-methoxyphenylboronic acid (MPB) and 4-biphenylboronic acid (BPB). The POB crystals were formed as precipitates in the solution and the morphology was considerably influenced by both the structure of the boronic anhydride and its concentration (C(B)). Needle-like crystals were firmed in the presence of TFB anhydride (TFBA) at C(B)S of 5 and 10 mol % by the spiral growth of lamellae. Spherical aggregates of slab-like crystals were formed at C(B)S from 50 to 100 mol %. The polymerization with MPB anhydride and BPB anhydride (BPBA) also yielded the needle-like crystals at C(B)S of 50 and 5 mol %, respectively. The polymerization with TFBA at lower C(B) was favorable to prepare the needle-like crystal. Molecular weight was also influenced by the structure of the boronic anhydride and C(B). M(n) increased generally with C(B) and BPBA gave the highest M(n) of 14.7 x 10(3) at C(B) of 100 mol %. The loose packing of the molecules in the crystal caused by the bulkiness of the end-groups made the polymerization in the crystals more efficiently. Morphology and molecular weight of the POB crystals could be controlled by the chemical structure and the content of boronic anhydride. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 1088-1096, 2011

DOI： 10.1002/pola.24521

Web of Science

researchmap

Micro-flowers of poly(p-phenylene pyromelliteimide) crystals 査読

Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

POLYMER   52 ( 3 )   837 - 843   2011年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Morphology control of poly(p-phenylene pyromelliteimide) (PPPI) crystals was examined using reaction-induced crystallization of oligomers during solution polymerization of self-polymerizable N-(4'-aminophenyl)-3-carboxyl-4-alkoxycarbonylPhthalimide. Micro-flowers of the PPP1 needle-like crystals were formed in which the needle-like crystals grew radially from the center part as petals. The molecules aligned regularly along the long axis of the needle-like crystal. The structure of alkoxy group in the monomer and the monomer concentration influenced the size of the needle-like crystals, and their average length and width were changeable from 640 nm to 1.69 mu m and from 110 nm to 210 nm, respectively. The average thickness was 20 nm. The obtained micro-flowers possessed high crystallinity and exhibited excellent thermal stability. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2010.12.022

Web of Science

researchmap

Preparation of Poly(p-phenylenepyromelliteimide) Microspheres with Rugged Surfaces Using Crystallization During Isothermal Polymerization 査読

Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULAR CHEMISTRY AND PHYSICS   212 ( 2 )   159 - 167   2011年1月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-V C H VERLAG GMBH  

Preparation of discrete PPPI microspheres was examined using the crystallization of oligomers during isothermal polymerization of PMDA and p-phenylene diisocyanate, and that of pyromellitic dithioanhydride and PPDA in poor solvents. In contrast to PPPI microspheres with smooth surfaces that were previously prepared by phase-separation during the polymerization of PPDA and PMDA, the microspheres obtained here consisted of flake-like lamellae with rugged surfaces. The diameters of the microspheres ranged from 0.5 to 6.7 mu m. They exhibited excellent thermal stability depending on the monomers. These results provide a new preparative procedure of the PPPI microsphere with a rugged surface.

DOI： 10.1002/macp.201000510

Web of Science

researchmap

One-Pot Preparation of Aromatic Poly(azomethine ester) Fibrillar Crystals Using Reaction-Induced Crystallization 査読

Jin Gong, Yasuhide Yakushi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   49 ( 1 )   127 - 137   2011年1月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL PUBLISHING, INC  

Polymerizations of 4-(4-acetoxybenzylideneamino)-benzoic acid were performed in dibenzyltoluene (DBT) and a mixture of DBT and liquid paraffin at 350 degrees C for 6 h. Fibrillar crystals of poly[4-(4-oxybenzylideneamino)benzoyl] (POAB) having the width of 50-450 nm and the length of over 15 pm were obtained by the crystallization during the polymerization. The fibrillar crystals possessed high crystallinity and the molecular chains aligned perpendicular to the long axis of the fibrillar crystals. Plate-like crystals were initially formed by the crystallization of oligomers, and then they changed to the fibrillar crystals via the formation of bundle-like crystals after 1 h. Molecular weight increased by the further polymerization in the crystals. Based on these results, one-pot preparation of the fibrillar POAB crystals was examined by the polymerization of 4-acetoxybenzaldehyde and 4-aminobenzoic acid. The polymerization at 180 degrees C for 2 h and then at 350 degrees C for 6 h afforded the fibrillar crystals with a small amount of the ribbon-like crystals. Although the side-reaction to generate the p-benzamide sequences was not completely depressed, the sequence of heating in which 180 degrees C for the formation of the azomethine linkage and then 350 degrees C for the formation of the ester linkage was preferable to prepare the fibrillar POAB crystals. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 127-137, 2011

DOI： 10.1002/pola.24427

Web of Science

researchmap

Preparation of poly(2-oxy-6-naphthoyl) and copolymers using reaction-induced phase separation during direct polymerization in the presence of boronic anhydride 査読

Masahiro Kihara, Shinichi Yamazaki, Kunio Kimura

POLYMER CHEMISTRY   2 ( 5 )   1195 - 1202   2011年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ROYAL SOC CHEMISTRY  

Poly(2-oxy-6-naphthoyl) (PON) was obtained as precipitates by direct polymerization of 2-hydroxy-6-naphthoic acid (HNA) in the presence of boronic anhydrides such as 2,4,6-tris(3,4,5-trifluorophenyl)-1,3,5,2,4,6-trioxatriborinane (TFBA) and 2,4,6-tri(biphenyl-4-yl)-1,3,5,2,4,6-trioxatriborinane (BPBA). The polymerizations were carried out in an aromatic solvent at 300 degrees C for 24 h. Both morphology and molecular weight of the PON precipitates were considerably influenced by not only the structure of the boronic anhydride but also its concentration (c(B)). Spheres with needles on their surface were formed in the polymerization with TFBA at c(B) of 50-70 mol%, and those having smooth surface were obtained at c(B) of 100 mol%. The M(n) increased with the value of c(B) in the range from 2.7 x 10(3) to 9.0 x 10(3). Aggregates of cone-like crystals were prepared in the polymerization with BPBA at c(B) of 10-30 mol%, and spheres having rugged surface were formed at c(B) of 50-100 mol%. The M(n) also increased with the value of c(B) in the range from 5.4 x 10(3) to 12.9 x 10(3). These PON precipitates possessed high crystallinity in spite of the morphology. The copolymerization of HNA and 4-hydroxybenzoic acid (HBA) was also examined in the presence of BPBA at c(B) of 100 mol% with varying the content of HBA in feed (r(f)). Copolymers were obtained as spheres of which the content of 4-oxybenzoyl moiety was lower than the value of r(f) due to the difference in the solubility of the oligomers.

DOI： 10.1039/c0py00420k

Web of Science

researchmap

Poly[2,6-(1,4-phenylene)-benzobisimidazole] Nanofiber Networks 査読

Jin Gong, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULAR CHEMISTRY AND PHYSICS   211 ( 20 )   2226 - 2232   2010年10月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-V C H VERLAG GMBH  

The preparation of poly[2,6-(1,4-phenylene)-benzobisimidazole] (PPBI) nanofibers was examined using the crystallization of oligomers during isothermal polymerization of self-polymerizable 2-(1,4-carbophenoxyphenyl)-5,6-diaminobenzimidazole. The polymerization was carried out at 350 degrees C at a concentration of 1w-t.-% for 6 h in three kinds of solvent. The solvent influenced the morphology of PPBI precipitates significantly, and PPBI nanofiber networks were successfully formed in DBT, of which the width ranged from 30 to 110 nm. Molecules were aligned along the long axis of nanofibers. A fibrillar morphology with molecular orientation is ideal for high performance materials such as reinforcements, non-woven fabrics and so on. The nanofiber networks exhibit the highest thermal stability.

DOI： 10.1002/macp.201000306

Web of Science

researchmap

Thermally Induced Solid-State Synthesis of Fluorine-Containing Poly(ether oxadiazole) 査読

Yuka Maruyama, Yukihiko Maeda, Kanji Wakabayashi, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF APPLIED POLYMER SCIENCE   118 ( 1 )   91 - 98   2010年10月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS INC  

Synthesis of poly[oxy-(2,3,5,6-tetrafluoro-1,4-phenylene)-(1,3,4-oxadiazol-2-yl)-1,4-phenylene] (F-PEOz) was examined by nucleophilic aromatic substitution reaction of 2-(4-hydroxyphenyl)-5-pentafluorophenyl-1,3,4-oxadiazole (HPOz). Only low molecular weight F-PEOz or crosslinked insoluble polymers were obtained by the solution polymerization with bases. In contrast, thermally induced solid-state polymerization of HPOz potassium salts at 180 degrees C for 1 h gave fully soluble F-PEOz with the yield of 84% and its reduced viscosity was 0.66 dL The longer polymerization time gave insoluble polymers due to the crosslinking reaction even in solid state. The solid-state polymerization did not undergo topochemically and it proceeded in an amorphous state. The crosslinking reaction was slightly inhibited by the solid-state polymerization. F-PEOz exhibited excellent solubility, high T(g) of 246 degrees C and good thermal stability. (c) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 91-98, 2010

DOI： 10.1002/app.32391

Web of Science

researchmap

Poly(2,5-benzimidazole) nanofibers prepared by reaction-induced crystallization 査読

Kazuya Kimura, Jin Gong, Shin-ichiro Kohama, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

POLYMER JOURNAL   42 ( 5 )   375 - 382   2010年5月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

Morphological control of poly(2,5-benzimidazole) (PBI) was examined by reaction-induced phase separation of oligomers during polymerization to prepare nanofibers. Three monomers, 3,4-diaminobenzoic acid (DABA), 3,4-diacetoamidebenzoic acid (DAcBA) and phenyl 3,4-diaminobenzoate (PDAB), were used to synthesize PBI. Polymerizations were carried out at 350 degrees C in a mixture of dibenzyltoluene isomers. Polymerization of DABA yielded spheres with plate-like crystals on their surface. Polymerization of DAcBA yielded almost no precipitates because of the high solubility of DAcBA oligomers. By contrast, polymerization of PDAB yielded aggregates of PBI nanofibers (of which the average diameter was similar to 60 nm), which resembled nonwoven fabrics. These fibers were formed by precipitation of (2,5-benzimidazole) oligomers and their subsequent polymerization into a developing crystal structure. The structure of the monomer significantly influenced the morphology of the PBI product, and PDAB was preferable for the preparation of PBI nanofibers. The temperature of 10% N-2 weight loss in these nanofibers was in the range of 634-644 degrees C and they were thermally stable. Polymer Journal (2010) 42, 375-382; doi:10.1038/pj.2010.20; published online 17 March 2010

DOI： 10.1038/pj.2010.20

Web of Science

researchmap

Formation and Morphology of “Shish-like” Fibril Crystals of Aliphatic Polyesters from the Sheared Melt 査読

Shinichi Yamazaki, Manabu Itoh, Takuya Oka, Kunio Kimura

European Polymer Journal   46 ( 1 )   58 - 68   2010年1月

　詳細を見る

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.eurpolymj.2009.09.003

Web of Science

researchmap

ポリエステル類のシシケバブ構造形成におけるエステル交換反応を介した絡み合い解消の影響 招待

山崎 慎一

Sen’i Gakkaishi   66 ( 7 )   237 - 239   2010年

　詳細を見る

記述言語：日本語  

DOI： 10.2115/fiber.66.P_237

researchmap

Direct Synthesis of Wholly Aromatic Polyamides by Using Reaction-Induced Crystallization 査読

Kazufumi Kobashi, Kentaro Kobayashi, Haruki Yasuda, Kentaro Arimachi, Testuya Uchida, Kanji Wakabayashi, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULES   42 ( 16 )   6128 - 6135   2009年8月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

Direct synthesis of rigid-rod aromatic polyamides was studied without condensation reagents by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of p-aminobenzoic acid were carried out in an aromatic solvent at a polymerization concentration of 20% at 350 degrees C. High molecular weight poly(p-benzamide) (PBA) was obtained in the form of plate-like crystals, and the highest molecular weight was 11.6 x 10(3). In this polymerization, the oligomers were formed in the solution by the condensation reaction with the elimination of water. When the molecular weight of oligomers exceeded the critical value, the oligomers were precipitated by crystallization via supersaturated state to form the plate-like crystals. The molecular weight increased by the polymerization between the oligomers on and in the crystals. Poly(p-phenylene isophthalamide) (PPIA) was also obtained in the form of plate-like crystals by the polymerization of p-phenylene diamine (PPDA) and isophthalic acid (IPA) under the same condition as that of PBA. These results exhibited the thermally direct synthesis of infusible aromatic polyamides. Sequential addition of monomers into this heterogeneous polymerization was examined to increase the molecular weight. In the step-growth polymerization, the addition of monomers into the homogeneous polymerization could not increase the molecular weight because it was determined by the extent of reaction and reshuffled by the transamidation reaction. However, the addition of PPDA and IPA during the polymerization resulted in the increase in the molecular weight of PPIA. This result gave possibly a novel procedure for the preparation of high molecular weight condensation-type polymers.

DOI： 10.1021/ma9009033

Web of Science

researchmap

Topological Mechanism of Nucleation of Cyclic Polyethylene

Shinichi Yamazaki, Shouichi Ida, Kunio Kimura

物性研究   92 ( 1 )   47 - 50   2009年4月

　詳細を見る

担当区分：筆頭著者,　責任著者   記述言語：英語  

researchmap

球晶成長速度をプローブにした脂肪族ポリエステル類のエステル交換反応を介した絡み合い解消の可能性の検証 査読

山崎 慎一, 岡 卓也, 木村 邦生

高分子論文集   66 ( 10 )   475 - 482   2009年

　詳細を見る

担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/koron.66.475

Web of Science

researchmap

Preparation of Poly(4 '-oxy-4-biphenylcarbonyl) Needlelike Crystals with the Aid of Copolymerization 査読

Naomi Yoshida, Yasuhiro Kurihara, Shin-ichiro Kohama, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULES   41 ( 20 )   7571 - 7578   2008年10月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

Preparation of poly(4'-oxy-4-biphenylcarbonyl) (POBP) needlelike crystals was examined by using reaction-induced crystallization of oligomers during copolymerization of 4-(4-aceloxypheilyl)benzoic acid (APBA) and 4-acetoxybenzoic acid (ABA). Polymerizations were carried out in aromatic solvent at various ABA molar ratios in feed (chi(f)). When they chi(f) was 20-10 mol %, starlike aggregates of needlelike crystals and fibrillated slablike crystals were separately formed, exhibiting similar morphology to poly(4-oxybenzoyl) and POPB crystals. 4-(Oxyphenyl)benzoyl (OPB) homo-oligomers and co-oligomers rich in OPB moiety were more rapidly precipitated due to the lower solubility, and the slablike crystals were formed. Afterward, 4-oxybenzoyl (013) homo-oligomers and the co-oligomers rich in OB moiety were precipitated to form spindlelike crystals. The OPB homo-oligomers and the co-oligomers rich in OPB moiety were continuously crystallized on both crystals due to the high degree of supersaturation. and the spindlelike crystals grew to the needlelike crystals mainly comprised of POBP. Copolymerization of 4-(4-acetoxybenzoyloxy)benzoic acid and APBA at chi(f) of 10 mol % yielded the needlelike crystals without coexisting fibrillated slablike crystals. This result provides a new methodology for morphology control with the aid of copolymerization.

DOI： 10.1021/ma800029n

Web of Science

researchmap

Preparation of brush-like crystals of poly[2,6-(1,4-phenylene)-benzobisimidazole] 査読

Jin Gong, Shin-ichiro Kohama, Kazuya Kimura, Shinichi Yamazaki, Kunio Kimura

POLYMER   49 ( 18 )   3928 - 3937   2008年8月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Poly[2,6-(1,4-phenylene)-benzobisimidazole] (PPBI) crystals were prepared by using reaction-induced crystallization of oligomers during solution polymerization of 1,2,4,5-tetraaminobenzene and diphenyl terephthalate. Polymerizations were carried out at a monomer concentration of 4.3 x 10(-2) mol L-1 at 350 degrees C for 6 h. Brush-like PPBI crystals were obtained in a mixture of structural isomers of dibenzyltoluene, in which many needle-like crystals came out vertically from the surface of the ribbon-like crystals. Average width and thickness of the ribbon-like crystals were 0.75 mu m and 0.11 mu m, respectively. And average length and diameter of the needle-like crystals were 0.36 mu m and 50 nm, respectively. The brush-like crystals possessed high crystallinity and exhibited good thermal resistance. The ribbon-like crystals were formed by the crystallization of imidazole oligomers at an initial stage of polymerization, and then the needle-like crystals grew from the surface of the ribbon-like crystals. Polymerization occurred on the crystals when the oligomers were crystallized, leading to the high molecular weight PPBI crystals. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2008.07.011

Web of Science

researchmap

Fabrication of rod-like crystals of poly(p-oxycinnamoyl) by hydrodynamically induced crystallization during solution polymerization 査読

Shin-ichiro Kohama, Mayuko Muraoka, Shinichi Yamazaki, Kunio Kimura

SEN-I GAKKAISHI   64 ( 8 )   220 - 223   2008年8月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC FIBER SCIENCE TECHNOLOGY  

Microspheres of poly(p-oxycinnamoyl) (POC) were obtained by the polymerization of (E)-4-acetoxycinnamic acid in aromatic solvent at 320 degrees C and a concentration of 1.5% without stirring via liquid-liquid phase separation of oligomers. In contrast to this, rod-like crystals were formed under shearing with more than 700 rpm. The obtained rod-like crystals were 10-15 mu m in length and 1.0-1.5 mu m in width having many thorns on the surface. The critical stirring speed for the onset of Taylor vortices was in agreement with 700 rpm and the crystallization of oligomers was hydrodynamically induced by the generation of Taylor vortices affording the rod-like crystals. Stirring influenced the morphology of POC significantly and this work provided a new procedure for the fabrication of fine fibers of intractable aromatic polymers.

DOI： 10.2115/fiber.64.220

Web of Science

researchmap

Preparation of poly(4-phthalimide) nanoribbon by reaction-induced crystallization 査読

Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura

MACROMOLECULES   41 ( 13 )   4607 - 4614   2008年7月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

The morphology of poly(4-phthalimide) (PPI) crystals was examined by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of alkyl 4-aminophthalates such as I-ethyl 4-aminophthalate (1EAP), 2-ethyl 4-aminophthalate, 1-hexyl 4-aminophthalate, and 2-hexyl 4-aminophthalate were carried out at 330 degrees C in a mixture of isomers of dibenzyltoluene without stirring. Nanoscale PPI ribbons having smooth surface were formed by the polymerizations of these monomers. The ribbons prepared from 1EAP at a concentration of 2.0% for 24 h were averagely 12 mu m in length, 150 urn in width, and 8 nm in thickness, in which the molecular chains aligned along the long axis of the ribbon. The phase-separated oligomers were fully cyclized imide oligomers, and this is of great importance for the formation of the ribbon. The obtained ribbons possessed high crystallinity and exhibited excellent thermal stability.

DOI： 10.1021/ma800874w

Web of Science

researchmap

Composition control of aromatic copolyesters by shearing 査読

Kunio Kimura, Toshimitsu Ichimori, Kanji Wakabayashi, Shin-ichiro Kohama, Shinichi Yamazaki

MACROMOLECULES   41 ( 12 )   4193 - 4199   2008年6月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

Composition control of copolyester was examined by using hydrodynamically induced phase separation, during solution polymerization, of p-acetoxybenzoic acid and m-acetoxybenzoic acid (m-ABA). Polymerizations were carried out in liquid paraffin at 1.0% of concentration under shear flow. The polymers were obtained as precipitates formed via phase separation of oligomers and the subsequent polymerization in the precipitates. When the feed ratio of m-ABA (chi(f)) was 20 mol %, the molar ratio of m-oxybenzoyl moiety in the precipitated polymers (chi(p)) was 5.3, 3.1, and 2.3 mol % at a shear rate (gamma) of 0, 147, and 489 s(-1), respectively. The values of chi(p) were much lower than those of chi(f), and shear flow lowered the value of chi(p); thus, controlling shear flow influenced both the reaction rate of the monomers and the miscibility of the oligomers. It especially enhanced the difference on the miscibility between homo-oligomers and co-oligomers. This change in the miscibility by shear flow brought about the more rapid precipitation of homo-oligomers than co-oligomers, leading to the selective formation of poly(p-oxybenzoyl).

DOI： 10.1021/ma800529d

Web of Science

researchmap

Improvement of adhesion and long-term adhesive reliability of liquid crystalline polyester film by plasma treatment 査読

Yasuhiro Kurihara, Hiroyuki Ohata, Masahiko Kawaguchi, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF APPLIED POLYMER SCIENCE   108 ( 1 )   85 - 92   2008年4月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS INC  

Surface modification of thermotropic liquid crystalline aromatic polyester (LCP) films was examined by low-pressure plasma treatment to improve initial adhesion and long-term adhesive reliability between the LCP film and an epoxy bonding sheet for printed circuit boards. Plasma irradiation was carried out in various plasma gases with different plasma modes as reactive-ion-etching (RIE), direct-plasma (DP) with pressures ranging from 4.0 to 26.6 Pa. Although the initial adhesion of the DP-treated film increased, the long-term adhesive reliability estimated by pressure cooker test (PCT) decreased with decreasing the plasma gas pressure in every gas. The higher concentration of the generated polar groups such as phenolic hydroxyl group and carboxyl group enhanced the initial adhesion by the increase in the chemical interaction; however, it damaged the long-term adhesive reliability due to the acceleration of the penetration of water molecules into the interface. The large surface roughness was effective to enhance the initial adhesion and the long-term adhesive reliability. The RIE-treatment generated the polar groups and the larger surface roughness than the DP-treatment. The RIE-treatment in the O-2 atmosphere at the gas pressure of 13.3 Pa was the best plasma condition for both the initial adhesion and the long-term adhesive reliability. (C) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/app.27537

Web of Science

researchmap

Morphology control of poly(2,2’-phenylene-5,5’-bibenzimidazole) by reaction-induced crystallization during polymerization 査読

Shin-ichiro Kohama, Jin Gong, Kazuya Kimura, Shinichi Yamazaki, Tetsuya Uchida, Kaoru Shimamura, Kunio Kimura

Polymer   49 ( 7 )   1783 - 1791   2008年4月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.polymer.2008.02.016

Web of Science

researchmap

Fluorinated poly(aryl thioether)s and poly(aryl sulfone)s derived from 2,3,4,5,6-pentafluorobenzoic acid 査読

Shunsuke Masaki, Natsuko Sato, Ai Nishichi, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF APPLIED POLYMER SCIENCE   108 ( 1 )   498 - 503   2008年4月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS INC  

Poly(aryl thioether)s (F-PTEs) containing 2,3,5,6-tetrafluoro-1,4-phenylene moiety and polar moiety, such as 1,3,4-ozadiazole, ether ketone, and amide groups, were synthesized by nucleophilic aromatic substitution reaction of aryl fluorides and 4,4'-thiobisbenzenthiol. F-PTEs were amorphous with good thermal properties including high glass transition temperature (T-g) and thermal stability, solubility, and hydrophobicity. F-PTEs were transformed into poly(aryl sulfone)s (F-PSs) by the oxidation reaction with hydrogen peroxide in acetic acid. Because of the sulfone group, the T(g)s of the F-PSs were 30-40 degrees C higher than those of the corresponding F-PTEs. F-PSs maintained solubility in polar aprotic solvents and exhibited hydrophobicity in spite of the content of polar sulfone groups due to the highly substituted fluorine atoms. These F-PTEs and F-PSs were a new class of high-performance polymers. (C) 2008 Wiley Periodicals, Inc.

DOI： 10.1002/app.27347

Web of Science

researchmap

Dimer effect on fractional polycondensation of poly(p-oxybenzoyl) 査読

Kunio Kimura, Yasuo Shimizu, Toshimitsu Ichimori, Shin-Ichiro Kohama, Shinichi Yamazaki, Yuhiko Yamashita

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   46 ( 5 )   1598 - 1606   2008年3月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS INC  

Selective preparation of poly(p-oxybenzoyl) (POB) crystals was examined from the viewpoint of a dimer effect on fractional polycondensation. Four different copolymerization systems were chosen as the combinations of p-acetoxybenzoic acid (p-ABA), m-acetoxybenzoic acid (m-ABA), and their dimers. The crystals obtained from the copolymerization of the dimer of p-ABA (p-ABAD) and m-ABA contained only 3.1 mol % of m-oxybenzoyl moiety even at high content of m-oxybenzoyl moiety in feed (chi(f)) of 40 mol %. p-Oxybenzoyl homo-oligomers were more rapidly formed from p-ABAD in the solution than from p-ABA, and they were crystallized to form the crystals with segregating co-oligomers. While co-oligomers containing more m-oxybenzoyl moiety were formed in the solution, afterward they were unable to be phase-separated because of higher miscibility. The further polycondensation proceeded in the precipitated crystal, and finally the POB crystal was selectively formed. Lower polymerization temperature and concentration enhanced the fractionability, and the POB crystals containing less than 1 mol % m-oxybenzoyl moiety were prepared at chi(f) of 30 mol %, 270 degrees C, and a concentration of 0.5%. The dimer effect on the fractional polycondensation was clearly observed. (C) 2008 Wiley Periodicals, Inc.

DOI： 10.1002/pola.22496

Web of Science

researchmap

Nonstoichiometric Synthesis of Poly(4,4’-oxydiphenylene pyromelliteimide) by Reaction-Induced Crystallization of Oligomers 査読

Kanji Wakabayashi, Shin-ichiro Kohama, Shinichi Yamazaki, Kunio Kimura

Macromolecules   41 ( 4 )   1168 - 1174   2008年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/ma702030u

Web of Science

researchmap

Improvement of Adhesion Between Liquid Crystalline Polyester Films by Plasma Treatment 査読

Yasuhiro Kurihara, Hiroyuki Ohata, Masahiko Kawaguchi, Shinichi Yamazaki, Kunio Kimura

JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY   22 ( 16 )   1985 - 2002   2008年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BRILL ACADEMIC PUBLISHERS  

Surface modification of thermotropic liquid crystalline aromatic polyester (LCP) films was carried out by low-pressure plasma treatment to improve the initial adhesion as well as the long-term adhesion reliability, a measure of durability between the LCP films used as substrates for printed circuit boards. Plasma irradiation was carried out in various plasma gases with different plasma modes such as reactive-ion-etching, and direct-plasma (DP) with pressures ranging from 6.7 Pa to 26.6 Pa. The introduction of polar groups on the film surface such as phenolic hydroxyl groups and carboxyl groups enhanced the initial adhesion by increased chemical interaction. However, if the concentration of polar groups became too high, the long-term adhesion reliability estimated by the pressure cooker test was degraded due to the acceleration of the penetration of water molecules into the interface. A large surface roughness was also effective in preventing the decrease in the long-term adhesion reliability. However, too much increase in surface roughness decreases the long-term adhesion reliability. The DP-treatment in the O(2) atmosphere at a gas pressure of 6.7 Pa was found to be the best plasma condition for both the initial adhesion as well as the long-term adhesion reliability between the LCP films. (C) Koninklijke Brill NV, Leiden, 2008

DOI： 10.1163/156856108X331751

Web of Science

researchmap

Fabrication of nanoribbon of high-performance polyimide

K. Wakabayashi, S. Yamazaki, T. Uchida, K. Kimura

American Chemical Society, Polymer Preprints, Division of Polymer Chemistry   49 ( 1 )   331 - 332   2008年

　詳細を見る

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Polymer Preprints ACS  

Scopus

researchmap

Synthesis and properties of fluorine-containing poly(aryl ether oxadiazole)s 査読

Natsuko Sato, Ken Tanaka, Shunsuke Masaki, Shinichi Yamazaki, Kunio Kimura, Al Nishichi

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   45 ( 14 )   2855 - 2866   2007年7月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS INC  

Fluorine-containing poly(aryl ether 1,3,4-ozadiazole)s were synthesized by the nucleophilic aromatic substitution reaction of 2,5-bis(2,3,4,5,6-pentafluorophenyl)-1,3,4-oxadiazole and various bisphenols in the presence of potassium carbonate. The polymerizations were carried out at 30 degrees C in 1-methyl-2-pyrrolidinone to avoid the gelation caused by a crosslinking reaction at para and ortho carbons to the 1,3,4-oxidiazole ring. The obtained polymers were all para-connected linear structures. The obtained fluorine-containing poly(aryl ether 1,3,4-ozadiazole)s showed excellent solubility and afforded tough, transparent films by the solution-casting method. They also exhibited a high glass transition temperature depending on the molecular structure, and the glass transition temperature could be controlled by the bisphenols in the range of 157-257 degrees C. They showed good thermal stability and excellent hydrophobicity due to the incorporation of the 2,3,5,6-tetrafluoro-1,4-phenylene moiety. (c) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/pola.22041

Web of Science

researchmap

Morphological architecture of poly(p-oxybenzoyl) by modification of oligomer end-group 査読

Kunio Kimura, Yasuhiro Kurihara, Hideki Omori, Shin-ichiro Kohama, Shinichi Yamazaki, Yuhiko Yamashita

POLYMER   48 ( 12 )   3429 - 3436   2007年6月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Influence of oligomer end-group on morphology of poly(4-oxybenzoyl) (POB) was examined by polymerizations of 4-acyloxybenzoic acids having different acyl groups. Polymerizations of 4-propionyloxybenzoic acid, 4-hexanoyloxybenzoic acid, 4-octanoyloxybenzoic acid and 4-decanoyloxybenzoic acid in liquid paraffin at 320 degrees C yielded needle-like or pillar-like POB crystals via crystallization of oligomers. On the other hand, the polymerization of 4-perfluorooctanoyloxybenzoic acid (FOBA) afforded microspheres having needle-like crystals on the surfaces. At an initial stage in the polymerization, microspheres having smooth surface were formed via liquid-liquid phase separation of oligomers prepared from FOBA owing to the low miscibility of perfluorooctanoyl end-group. Thereby the phase-separation behaviour of oligomers changed from liquid-liquid phase separation to crystallization at a middle stage in the polymerization and then needle-like crystals were formed on the surface of the microspheres. Chemical structure of the oligomer end-group affected significantly the phase-separation behaviour of oligomers and ultimately the morphology of POB. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2007.04.025

Web of Science

researchmap

流動場結晶化における異形微粒子添加によるshish構造形成の促進

山崎 慎一, 若林 完爾, 水間 健太, 木村 邦生

岡山大学環境理工学部研究報告   12 ( 1 )   157 - 160   2007年3月

　詳細を見る

記述言語：日本語   出版者・発行元：岡山大学環境理工学部  

We have shown that the shish was formed from the oriented melt composed of the elongated chains caused by dust particles within the melt via bundle typed nucleation under flow with low shear rate (γ=5s(-1)). This implies that dust particles effectively cause the elongation of chains within the melt. In this work, we observed the crystallization of polypropylene added with irregular shaped particles under shear flow by means of polarizing optical microscope. We prepared various shaped particles such as confetti-like, spherical and rock-like. We found that the size and asymmetric shape of additive particles play an important role for the acceleration of formation of shish.

CiNii Article

CiNii Books

researchmap

結晶化処理を用いたポリブチレンテレフタレートの効果的鎖延長反応の開発

井原 誠司, 城間 弥, 山崎 慎一, 木村 邦生

岡山大学環境理工学部研究報告   12 ( 1 )   167 - 171   2007年3月

　詳細を見る

記述言語：日本語   出版者・発行元：岡山大学環境理工学部  

Plastics are quite important materials for not only industrial usages but also our daily life. Many plastics are difficult to reuse because they are susceptible to UV, hydrolysis and so on leading to the reduction of molecular weight. Among them, poly (butylenes terephthalate) (PBT) is a valuable materials prepared by polycondensation reaction, and PBT has the same limitation to reuse. Hence, efficient chain extension reaction for recovered PBT has been needed to improve the properties damaged by chain scission. In this study, new chain extension reaction had been examined by using crystallization as pre-treatment. Isothermal crystallization at 161℃ concentrated the chain end-groups on the surface of the crystals, and chain extension reaction at 210℃, which was lower than the melting temperature of PBT, enhanced the molecular weight significantly compared with the reaction over the melting temperature. It concluded that the pre-treatment of crystallization was favorable for the efficient chain extension reaction and this result provided the new technology for the effective reuse of the plastics.

CiNii Article

CiNii Books

researchmap

Fabrication of particles and crystals of poly(p-phenylene pyromelliteimide) and the study on crystal structure 査読

Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura, Kaoru Shimamura

MACROMOLECULES   40 ( 2 )   239 - 246   2007年1月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

Morphologies of poly(p-phenylene pyromelliteimide) (PPPI) were investigated by using phase separation during polymerization of pyromellitic dianhydride (PMDA) and p-phenylene diamine (PPDA). Polymerizations were carried out at 330 degrees C for 6 h. PPDA was added to the solution of PMDA in an aromatic solvent at various temperatures after PMDA was entirely dissolved. The morphology of the precipitates was drastically changed with the temperature of PPDA addition (Tad). When Tad was 240 degrees C, the fine particles were formed through the formation of droplets via liquid-liquid phase separation. On the contrary, when Tad was higher than 280 degrees C, the mixture of lozenge-shaped crystals and starlike aggregates of needlelike crystals were formed by the crystallization of oligomers. Tad influenced the degree of imidization of oligomers, resulting in the variation in the morphology of PPPI. Crystal structure and molecular chain orientation of the lozenge-shaped crystals were also investigated by high-resolution transmission electron microscope.

DOI： 10.1021/ma062032y

Web of Science

researchmap

Morphology control of various aromatic polyimides by using phase separation during polymerization 査読

Kanji Wakabayashi, Shin-ichiro Kohama, Shinichi Yamazaki, Kunio Kimura

POLYMER   48 ( 2 )   458 - 466   2007年1月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

Morphology control of various aromatic polyimides representative as poly(4,4'-oxydiphenylene pyromelliteimide) was examined by using the phase separation during solution polymerization. Polymerizations of aromatic dianhydrides and aromatic diamines to the polyimides were carried out in poor solvents at 240-330 degrees C for 6 h with no stirring. Polymerization concentrations were from 0.25% to 3.0%. The polyimides were obtained as yellow precipitates. Two categorized morphologies were created, which were particles and crystals exhibiting lath-like and plate-like habits. These morphologies of polyimides could be selectively controlled by the polymerization conditions. The higher concentrations, less miscible solvents and lower temperatures were preferable to yield the particles via liquid-liquid phase separation. On the contrary, the lower concentration, miscible solvents and higher temperature were desirable to yield the crystals. The polyimide precipitates showed high crystallinity and possessed excellent thermal stability at which the 10 wt% loss temperatures in N-2 were in the range of 590-694 degrees C. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2006.11.061

Web of Science

researchmap

リサイクル性に優れたセルフコンポジット型高強度・高耐熱性プラスチック材料の開発 招待

山崎 慎一

ポリファイル   44 ( 518 )   30 - 34   2007年

　詳細を見る

記述言語：日本語  

researchmap

Two-step formation of entanglement from disentangled polymer melt detected by using nucleation rate 査読

Shinichi Yamazaki, Fangming Gu, Kaori Watanabe, Kiyoka Okada, Akihiko Toda, Masamichi Hikosaka

POLYMER   47 ( 18 )   6422 - 6428   2006年8月

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

"How do chain molecules spontaneously entangle from completely disentangled polymer melt?" remains the most interesting unsolved problem. In order to solve this problem, we used the concept that the melt of "nascent" polymer crystallized during polymerization just after melting does not include any entanglements. We succeeded in detecting the increase of entanglement density v(e) with the increase of annealing time At above the equilibrium melting temperature before isothermal crystallization. The increase of v(e) was detected by observing the decrease of nucleation rate I from the melt of nascent polymer with different Delta ts. I is a very sensitive detector of entanglements because the nucleation is a rearrangement process of chains to the crystalline lattice through the disentanglement. Therefore, I is significantly suppressed with the increase of v(e). We found a two-step decrease of I with an increase of Delta t for the first time. This should correspond to a two-step increase of v(e) with an increase of Delta t. This indicates that simple entanglements such as twist or knot with lower order (one time knot) were formed within short time and then the complicated ones such as knot with higher order (two or three times knots) or loops (entanglements by loop conformation) were formed. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2006.07.010

Web of Science

researchmap

Novel fluorine-containing poly(aryl ether amide)s derived from 2,3,4,5,6-pentafluorobenzoic acid 査読

Ken Tanaka, Natsuko Sato, Shinichi Yamazaki, Kunio Kimura, Yuhiko Yamashita

SEN-I GAKKAISHI   62 ( 7 )   155 - 161   2006年7月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC FIBER SCIENCE TECHNOLOGY  

Various amide-containing aryl fluorides were synthesized from 2,3,4,5,6-pentafluorobenzoic acid, and novel fifteen AA-BB type and three AB type fluorine-containing poly(aryl ether amide)s (F-PEA) were obtained by nucleophilic aromatic substitution reaction. The synthesized aryl fluorides possessed several reactive carbons for the nucleophilic attack and cross-linking reaction occurred at 100 degrees C. Polymerizations were carried out at 80 degrees C to avoid cross-linking and stopped just before gelation occurred. They had all para connected linear structures. The obtained F-PEAs showed excellent solubility and afforded tough transparent films by casting method. They also exhibited high Tg in the range of 179-273 degrees C depending on the molecular structure. They showed good thermal stability, and even though F-PEAs contained amide linkage into the repeating unit of polymer molecule, they exhibited excellent hydrophobicity due to the incorporation of 2,3,5,6-tetrafluoro-1,4-phenylene moiety.

DOI： 10.2115/fiber.62.155

Web of Science

researchmap

Fabrication of poly(p-oxycinnamoyl) nano-scale particles 査読

Yoshito Hirai, Shin-ichiro Kohama, Shinichi Yamazaki, Kunio Kimura

SEN-I GAKKAISHI   62 ( 7 )   167 - 174   2006年7月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC FIBER SCIENCE TECHNOLOGY  

Fabrication of poly(p-oxycinnamoyl) (POC) nano-scale particles was examined by using self-seeding polymerization of (E)-4-acetoxycinnamic acid in liquid paraffin. The diameter of the POC spheres was very susceptible to the polymerization temperature and the temperature drop was very efficient to control the nucleation process by the adjustment of the degree of super saturation leading to the decrease in the diameter. The average diameter of the spheres prepared at 320 degrees C was 3.6 mu m, whereas, the temperature drop from 320 degrees C to 250 degrees C just before the nucleation afforded the POC microspheres having average diameter of 2.2 mu m. In order to prepare the nano-scale particles, only the self-seeding polymerization was not sufficient and the control of the growth process was additionally required. The POC particles having 600 nm of the average diameter were obtained by not only the temperature change from 320 degrees C to 250 degrees C and then 320 degrees C but also the addition of 4-octadecyloxybiphenyl as a coalescence inhibitor. The average diameter was in nano-scale, but the diameter distribution became broader with bimodality.

DOI： 10.2115/fiber.62.167

Web of Science

researchmap

New attempt at preparation of fluorine-containing poly(ether ketone)s in supercritical carbon dioxide

Kunio Kimura, Shinichi Yamazaki, Patrick E. Cassidy, John W. Fitch, Sreenu R. Venumkbaka

岡山大学環境理工学部研究報告   11 ( 1 )   93 - 97   2006年3月

　詳細を見る

記述言語：英語  

researchmap

Acceleration mechanism of growth rates under shear flow due to the oriented melt - The novel morphology of spiral crystal (spiralite) 査読

K Watanabe, K Okada, A Toda, S Yamazaki, T Taniguchi, K Koyama, K Yamada, M Hikosaka

MACROMOLECULES   39 ( 4 )   1515 - 1524   2006年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

Isothermal crystallization of three-dimensional (3D) spherulites from the bulky melt under low shear rate flow was Studied based on new in situ observation along a direction perpendicular to the flow velocity a adient plane (XZ plane) by means Of optical microscope, where X- and Z-axes are perpendicular and parallel to the flow direction, respectively. Spherulites are rotating. A novel "spiral pattern" was found oil the surface of the rotating "half-spherulite" near the surface of the melt for the first time. The half-spherulite is named "spiralite" which enabled us to have a visible image of the rotation of Spherulite. Hence, we could detect the growth rate around the Z-axis V(Z) and that around the X-axis V(X) by using the spiral pattern. We could experimentally obtain V(Z) > V(X) in this study. From kinetic viewpoint. this fact indicates that free energy for formation of a critical nucleus around file Z-axis is smaller than that around the X-axis. From this, it is concluded that the 1 oriented melt" is formed around the 7 axis. We proved it theoretically by showing that micro shear rate (Z) on the interface around the Z-axis significantly increases and chains will be elongated even when macro is low (y < 10 s(-1)). With increase of y(Z), the chain elongation will overcome the entropic relaxation, that results in formation of the "oriented melt". Crystallization mechanism under low shear flow is proposed that file growth rate of spherulite or shish is accelerated around interface, due to formation of the "oriented melt". Finally, we proposed a possible relationship between Inch Structure and crystallization under anisotropic and isotropic external fields.

DOI： 10.1021/ma050825z

Web of Science

researchmap

Morphology control of aromatic polymers in concert with polymerization 査読

Kunio Kimura, Shin-ichiro Kohama, Shinichi Yamazaki

POLYMER JOURNAL   38 ( 10 )   1005 - 1022   2006年

　詳細を見る

記述言語：英語   出版者・発行元：NATURE PUBLISHING GROUP  

Morphology control methods of aromatic polymers in concert with polymerization reaction are described in this review. Many attractive methods have been developed including reaction-induced phase separation of oligomers, epitaxial polymerization, shear-induced chain orientation during gelation, template-based polymerization, suspension polycondensation, solid-state polycondensation and liquid-liquid interfacial precipitation and so on. Among them, the reaction-induced phase separation of oligomers, in which there are two modes of crystallization and liquid-liquid phase separation, possess practically high potentiality to create novel polymer materials since it can control not only the morphology but also the molecular chain orientation. Ultimate goal is the embodiment of the nature system in a flask, that is, the control of the materials from primary structures to super structures. The morphology control methods by using polymerization reaction afford the valuable methodology for the three-dimensional structure architecture.

DOI： 10.1295/polymj.PJ2006083

Web of Science

researchmap

Morphology control of polybenzimidazole by using reaction-induced phase separation of oligomers during solution polymerization

Shin-Ichiro Kohama, Shinichi Yamazaki, Kunio Kimura, Jin Gong, Kaoru Shimamura

Polymer Preprints, Japan   55 ( 2 )   2852   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

This paper deals with a new finding on the morphology control of poly[2,2′-(p-phenylene)-5,5′-bibenzimidazole] (PBI) by using the reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of 3,3′-diaminobenzidine and diphenyl terephthalate or terephthalic acid were carried out at 350°C for 6 hours in poor solvent such as dibenzyl toluene mixture to induce the crystallization of oligomers. Bundle-like aggregates of PBI nanofibers and plate-like PBI crystals were prepared with high yields. The values of inherent viscosity of FBI were 0.49 - 0.58 dL/g. Obtained crystals possessed high crystallinity measured on WAXS and good thermal stability. The morphology of the products was drastically influenced by the end-group structure of phase separated oligomers.

Scopus

researchmap

Nucleation and entanglement of cyclic polyethylene

Shouichi Ida, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   55 ( 2 )   3125 - 3126   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Previously, we have shown the hierarchised model of entanglements of polymer chains based on melt annealing time Δt dependence of nucleation rate I of "nascent" linear polyethylene (nascent L-PE). This work showed the validity of above model and role of "knot" entanglement in the nucleation of polymers using cyclic polyethylene (C-PE) which can not form the knot entanglement. We found that I of C-PE was remarkably larger than that of L-PE. Moreover, we found that I of C-PE monotonically decreased with increasing Δt. These imply that the knot entanglement plays an important role in the nucleation.

Scopus

researchmap

Synthesis of novel fluorine-containing poly(ether sulfone)s by using chemical modification reaction

Shunsuke Masaki, Ai Nishichi, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   55 ( 1 )   189   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

This paper described the synthesis of novel fluorine-containing aromatic poly(ether sulfone)s (F-PES) by the oxidation of the corresponding fluorine-containing polythioethers (F-PTEs) derived from 2,3,4,5,6- pentafluorobenzoic acid. F-PTEs were synthesized by nucleophilic aromatic substitution reaction at relative low temperature in DMF. F-PTEs obtained by stopping just before the gelation were all para connected linear structures. The obtained F-PESs showed higher Tg than that of F-PTEs due to the introduction of sulfone units. They also exhibited excellent solubility and good hydrophobicity due to the incorporation of 2,3,5,6-tetrafluoro-1,4-phenylene moiety.

Scopus

researchmap

Nonstoichiomeric polymerization of polyimide by using reaction-induced crystallization of oligomers

Kanji Wakabayashi, Takuya Ito, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   55 ( 1 )   281   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Nonstoichiometric preparation of poly(4,4'-oxydiphenylene pyromelliteimide)(Kapton) from pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA) was examined by using reaction-induced crystallization of oligomers. When the polymerization was carried out under stoichiometric condition, the crystals having ηinh of 1.58 dL/g were obtained. Under the excess ODA, ηinh was insensitive toward the imbalance of stoichiometry, and suprisingly, ηinh became 1.63 dL/g even under 50 mol% excess. In the polymerization under nontoichiometric condition, the terminated oligomers precipitated to form the crystals and the solid-state polymerization proceeded with the elimination of terminated oligomer unit in oligomer crystals resulting in high molecular weight.

Scopus

researchmap

Improvement of adhesion between liquid crystalline polymer film and epoxy by cold plasma treatment

Yasuhiro Kurihara, Shinichi Yamazaki, Kunio Kimura, Hiroyuki Ohata, Masahiko Kawaguchi

Polymer Preprints, Japan   55 ( 1 )   2349   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

We investigated the surface modification of thermotropic liquid-crystalline polymer (LCP) film made of wholly aromatic copolyester by O2 reactive-ion-etching (RIE) and O2, N2, N 2/H2(7/3) direct-plasma (DP) to improve the adhesion and the long-term reliability of the adhesion between the LCP film and epoxy, which is typically used as bonding sheet for printed circuit boards. About the peel strength before and after Pressure Cooker Test (PCT), which was conducted to determine the long-term reliability, the peel strength before PCT was increased with decreasing pressure in O2, N2 DP, whereas the peel strength after PCT was decreased with decreasing pressure in O2 RIE and O2, N2 DP . The XPS analysis conducted on the LCP film surface treated with O2 RIE and O2 DP implied that a higher number of phenol hydroxyl groups were generated at low-pressure and the peel strength before and after PCT was affected. Moreover, it is speculated that if N functional groups are introduced by the plasma treatment of the gas containing N2, the decrease of the peel strength after PCT will become significant. The surface roughness of the film was increased with increasing pressure in O2 RIE, and it was assumed that the peel strength before and after PCT was based on the synergistic effect of functional groups and the surface roughness.

Scopus

researchmap

Preparation of polybenzimidazole nanofibers by using reaction-induced crystallization of oligomers during solution polymerization

Shin-Ichiro Kohama, Jin Gong, Shinichi Yamazaki, Kunio Kimura, Kaoru Shimamura

Polymer Preprints, Japan   55 ( 1 )   546   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

This paper deals with our new finding on the fabrication of poly[2,2'-(p-phenylene)-5,5'-bibenzimidazole] (PBI) nanofibers by using the crystallization of oligomers during solution polymerization. Polymerizations of 3,3'-diaminobenzidine and diphenyl terephthalate were carried out at 320 and 350°C for 6 hours in poor solvents to induce the crystallization of oligomers. The solvents used in this study were liquid paraffin (LPF) and Barrel Therm 400 (BT4, Matsumura Oil Co., Ltd.), which is the mixture of dibenzyl toluene. In the polymerizations in LPF, plate-like crystals of PBI were obtained and their inherent viscosities (ηinh) were 0.21 - 0.27 dL/g. On the other hand, in the polymerization in BT4, the bundle-like aggregates of PBI nanofibers were prepared with quantitative yields. The diameter of each nanofibers was 20 - 100 nm. The values of ηrinh of PBI nanofibers were 0.35 - 0.58 dL/g and they were higher than those in LPF. These nanofibers possessed extremely high crystallinity measured on WAXS and good thermal stability. The morphology was drastically influenced by the solvent, and the control of miscibility is of great importance for the fabrication of PBI nanofibers.

Scopus

researchmap

Possibility of disentanglement process of condensation polymer by transesterification proof by growth rate of spherulite

Takuya Oka, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   55 ( 1 )   818   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

In order to proof of the possibility of disentanglement process of condensation polymers via transesterificartion, we measured the growth rate of spherulite (G) of PLLA as a function of melt annealing time (Δt) before isothermal crystallization. We prepared three PLLA samples by means of reaction induced crystallization of oligomers during polymerization. For the sample with unclear crystal habit, we found that G was almost constant at Δt&lt
30 min, and then monotonially decreased with increasing Δt. From GPC measurements, we confirmed that molecular weight did not change and molecular weight distribution became broad. This implies that condensation polymers within the melt disentangle via transesterification.

Scopus

researchmap

Copolymerization effect on morphology of polymer crystals prepared from 4-acetoxybenzoic acid and 4-(4-acetoxyphenyl)benzoic acid

Naomi Yoshida, Yasuhiro Kurihara, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   55 ( 1 )   547   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

We had been studying a dual self-assembling polycondensation system by means of phase separation of oligomers, which is a novel polycondensation system to prepare separately the two kinds of polymer crystals having different structures. This phenomenon was induced by the difference in the oligomer interaction such as hydrogen bonding. In this study, a dual self-assembling polycondensation was found in the solution polymerization of 4-acetoxybenzoic acid (ABA) and 4-(4-acetoxyphenyl)benzoic acid (APBA). Two different kinds of crystals were simultaneously formed, of which one was needle-like crystal and another was fibrillated slab-like crystals. These morphologies resembled those of corresponding homopolymer crystals. Microscopic FT-IR analysis suggested that these two crystals had different structure. The miscibility of the oligomers prepared from APBA was quite lower than those from ABA, and this large difference in the miscibility may induce the simultaneous formation of two kinds of crystals having different crystal habit.

Scopus

researchmap

Preparation of aromatic polyesters by using fractional polycondensation under shearing condition

Chie Iwado, Shin-Ichiro Kohama, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   55 ( 1 )   545   2006年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

We have found that poly(p-oxybenzoyl) (POB) was selectively prepared by the fractional polycondensation of p-acetoxybenzoic(p-ABA) acid and m-acetoxybenzoic acid in poor solvents by using the phase separation of oligomers, and shearing was of importance for the fractionability. In this study, fractional polycondensation of POB was examined in the copolymerization of p-ABA and 3-(4-acetoxyphenyl)propionic acid (p-APPA) to clarify the shearing effect on the fractionability. This copolymerization had also fractionability and the precipitates rich in p-oxybenzoyl moiety were selectively obtained. The shearing enhanced the fractionability and the content of p-oxybenzoyl moiety of the precipitates prepared at the content of ABA in feed of 70mol% was 92.6%, which was almost POB. The shearing increased the solubility of cooligomers and therefore, this provided the suitable circumstance that homo-oligomers were selectively phase-separated.

Scopus

researchmap

Topological Mechanism of Polymer Nucleation and Growth – The Role of Chain Sliding Diffusion and Entanglement 招待 査読

Advances in Polymer Sciences   191   137 - 186   2005年10月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/12_010

Web of Science

researchmap

Formation mechanism of shish in the oriented melt (II) - two different growth mechanisms along and perpendicular to the flow direction 査読

S Yamazaki, K Watanabe, K Okada, K Yamada, K Tagashira, A Toda, M Hikosaka

POLYMER   46 ( 5 )   1685 - 1692   2005年2月

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

In part I of this series of paper, we have solved the formation mechanism of shish from the oriented melt based on the kinetic observation. In this work, we have shown for the first time the molecular mechanism of the growth of shish by kinetic study. We found that there are two different type of the growth of shish against the flow direction. The growth rate along the flow direction (U) is proportional to DeltaT, where DeltaT is the degree of supercooling. This indicates that U is mainly controlled by the rearrangement process of the chain near the end surface of the shish. On the other hand, the growth rate perpendicular to the flow direction (V) obeyed a well-known equation Vproportional to exp(-B/DeltaT), where B is a constant proportional to the free energy necessary for forming a critical secondary nucleus DeltaG*. This indicates that V is mainly controlled by the secondary nucleation process on the side surface of shish. Moreover, we also found that there is a critical shear rate gamma (over dot)* for the growth of shish. Below gamma (over dot)*, U and V approached to zero and the growth rate of spherulite, respectively. From this experimental fact, we proposed that the chain conformation near the interface between the melt and shish, i.e. near the end and side surface of shish is elongated and oriented by the shear flow above gamma (over dot)*. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2004.12.010

Web of Science

researchmap

Electrical conductivity and electromagnetic interference shielding effectiveness of polyaniline-ethylene vinyl acetate composites 査読

NC Das, S Yamazaki, M Hikosaka, TK Chaki, D Khastgir, A Chakraborty

POLYMER INTERNATIONAL   54 ( 2 )   256 - 259   2005年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JOHN WILEY & SONS LTD  

Electrical conductivity and electromagnetic interference (EMI) shielding effectiveness at microwave (200-2000 MHz) and X-band (8-12 GHz) frequency range of polyaniline (PAni) composites were studied. It has been observed that EMI shielding of conductive polyaniline (PAni)-ethylene vinyl acetate composites increases with the increase in the loading levels of the conductive polymer doped with dodecylbenzene sulfonic acid. The result indicates that the composites having higher PAni loading (> 23%) can be used for EMI shielding materials and those with lower PAni loading can be used for the dissipation of electrostatic charge. (C) 2004 Society of Chemical Industry.

DOI： 10.1002/pi.1660

Web of Science

researchmap

Formation mechanism of shish in the oriented melt (I) - bundle nucleus becomes to shish 査読

S Yamazaki, K Watanabe, K Okada, K Yamada, K Tagashira, A Toda, M Hikosaka

POLYMER   46 ( 5 )   1675 - 1684   2005年2月

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

We have solved the molecular mechanism of the formation of shish of isotactic-polypropylene (iPP) and polyethylene (PE) from the sheared melt based on kinetic study by means of polarizing optical microscope. We found that the rate determining process for the formation of shish is a nucleation process in the most range of degree of supercooling (DeltaT) except for large DeltaT of PE. We have shown a direct evidence of the formation of bundle nucleus from the oriented melt, which is consisted of elongated chains caused by artificial pins. For polymers, a universal mechanism of nucleation from the isotropic or oriented melt was proposed. We also found that there is a critical shear rate for the formation of shish. This experimental fact indicates that the shish will be formed when the elongation of chains will overcome the conformational relaxation of chains and chain conformation within the oriented melt is kept liquid crystal like one. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2004.12.009

Web of Science

researchmap

Fabrication of poly(p-oxybenzoyl) nanowhisker 査読

K Kimura, S Yamazaki, Y Matsuoka, Y Yamashita

POLYMER JOURNAL   37 ( 12 )   906 - 912   2005年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

Fabrication of poly(p-oxybenzoyl) (POB) nanowhiskers was examined by using reaction-induced crystallization of oligomers during the polymerization of p-acetoxybenzoic acid in liquid paraffin. Width of the POB whiskers was susceptible to polymerization temperature and it was efficiently controlled by a change in temperature during the polymerization. Increase in polymerization temperature just after nucleation (Han) reduced the degree of super saturation of oligomers (or) resulting in the depression of the width increase by the crystallization of oligomers on side surface of the whiskers. Temperature drop just before nucleation (Cbn) enhanced the value of a resulting in the generation of much more nuclei having the smaller width. On the basis of these results, the combination of these two methods Han and Cbn afforded the whiskers having the smallest width, and the POB nanowhiskers were prepared of which the width and the length were 190nm and 18.6 mu m, respectively.

DOI： 10.1295/polymj.37.906

Web of Science

researchmap

Morphology control of poly(p-oxycinnamoyl) by direct polycondensation with aromatic anhydride

Toshimitsu Nakanishi, Shin-Ichiro Kohama, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   54 ( 1 )   1824   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Direct polycondensation of p-hydroxycinnamic acid was carried out in the presence of an aromatic anhydride such as benzoic anhydride and p-ethoxybenzoic anhydride by means of reaction-induced phase separation of oligomers. Poly(p-oxycinnamoyl) (POC) spheres were prepared in liquid paraffin in the presence of both aromatic anhydrides at 280 - 320°C. On the other hand, POC crystals having clear habits were prepared in hydrogenated terphenyl mixture in the presence of p-ethoxybenzoic anhydride at 260°C. Especially, POC needle-like crystals were prepared in good yield at 260°C at a concentration of 10.0 %. WAXS patterns of POC plate-like and needle-like crystals showed that these crystals possessed quite high crystallinity compared with POC spheres. It was concluded that the morphology of POC was tunable by not only the solvent but also the aromatic anhydride as condensation reagent.

Scopus

researchmap

Formation of shish under flow with low shear rate - Effect of addition of irregular shaped particles

Shinichi Yamazaki, Kanji Wakabayashi, Kenta Mizuma, Kunio Kimura

Polymer Preprints, Japan   54 ( 2 )   3157 - 3158   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Previously, we have shown that the shish was formed from the oriented melt composed of the elongated chains caused by dust particles within the melt via bundle typed nucleation under flow with low shear rate ( γ̇
=5s -1). This implies that dust particles effectively cause the elongation of chains within the melt. In this work, we observed the crystallization of iPP added with irregular shaped particles under shear flow by means of polarizing optical microscope. We prepared various shaped particles such as confetti-like, spherical and rock-like. We found that the size and asymmetric shape of additional particles are important for effective formation of shish.

Scopus

researchmap

Influence of shearing on fractutional polycondensation of aromatic polyester

Chie Iwado, Toshimitsu Ichmori, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   54 ( 2 )   2679   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Selective preparation of poly(p-oxybenzoyl) (POB) in copolymerization system of p-acetoxybenzoic acid (p-ABA) and m-acetoxybenzoic acid (m-ABA) was examined by using reaction-induced crystallization under shearing condition. POB crystals were mainly precipitated in liquid paraffin solution even at the content of m-ABA in feed (χf) of 30 mol% without stirring. In contrast to this, they were formed even at χf of 50 mol% and the fractionability was significantly enhanced by shearing. The mechanism of the fractional polycondensation was attributed to both the reactivity of monomer and the phase separation behavior of oligomer. Under shearing condition, the difference on the reactivity between p-ABA and m-ABA was lowered. However, the shearing induced the crystallization of homo-oligomers of p-oxybenzoyl unit more efficiently and prevented the precipitation of co-oligomers via crystallization. Thereby homo-oligomers were more rapidly and selectively precipitated by crystallization to form the POB crystals.

Scopus

researchmap

Solid-state polycondensation of aromatic polyimide by means of crystallization of oligomers during solution polymerization

Kanji Wakabayashi, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   54 ( 2 )   2555   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Poly(4,4'-oxydiphenylene pyromelliteimide)(PI(PMDA/DPE)) were prepared from PMDA and DPE as monomers at condition of 0.50% and 280°C in TS10 (mixture of isomers of dibenzyltoluene). Lath-like crystals and particles composed with plate-like crystals were obtained via the crystallization of oligomers during solution polymerization. The products exhibited high crystallinity and high inherent viscosity of 1.17 dig-1. This implies solid-state polymerization effectively progressed in the crystals of oligomer, because the chain ends in the oligomers crystal were advantageously arranged for polycondensation reaction.

Scopus

researchmap

Fabrication of poly(p-oxycinnamoyl) needle crystals by using hydrodynamically induced crystallization during solution polymerization

Mayuko Muraoka, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   54 ( 1 )   600   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Morphology control of poly(p-oxycinnamoyl) (POC) was studied to overcome the poor processability and microspheres were prepared by the self-organizing polycondensation of (E)-4-acetoxycinnamic acid (ACA) in aromatic solvent at 320°C without stirring. The work reported investigated the fabrication of POC needle crystals by hydrodynamically induced crystallization during polymerization of ACA. Polymerizations of ACA were carried out in a cylindrical vessel equipped with a stirring bar at a concentration of 1.5% under stirring with different speed (γ) of 300, 700 and 1100 rpm. Microspheres were obtained at γ of 300 rpm via liquid-liquid phase separation. In contrast to this, morphology was drastically changed from sphere to needle at γ of 700 and 1100 rpm These needle crystals were obtained with the yield of 22-27 %, which were 1.0-1.5 μm in length and 1.0-1.5 μm in width. The purely laminar flow in the cylindrical vessel at low stirring speed changed to Taylor vortices with the increase of γ and this brought about the huge concentration of oligomers along to the circular flow leading to the crystallization to form the needle crystals.

Scopus

researchmap

Direct synthesis of polyamides by using crystallization during polymerization

Kentaro Kobayashi, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   54 ( 1 )   304   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Direct polycondensations of isophthalic acid (IPA) and p-phenylenediamine (PPDA) were carried out by means of reaction-induced crystallization of oligomers. Poly(p-phenylene isophthalamide) (PPIA) plate-like crystals were obtained in good yield. The crystals exhibiting clear habits possessed high crystallinity. PPDA / IPA = 1.4 - 1.5 gave the highest intrinsic viscosity ([η]) of 0.37 dl/g. The yield and [η] of the polymers and the dissolved oligomers were measured in the course of the polymerization in order to examine polycondenastion feature. [η] of the polymers was increased even after the polymer yield was leveled off. On the other hand, [η] of the dissolved oligomers was constant through the polymerization. From these results, it was concluded that the polycondensation of IPA and PPDA proceeded as follows. When the molecular weight of oligomers exceeded the critical value, they were crystallized to form crystals. Solid-state polycondensation subsequently occurred in the crystals. Finally, PPIA were obtained as a form of crystals.

Scopus

researchmap

Synthesis of novel fluorine-containing poly(oxadiazole-ether)s

Natsuko Sato, Shunsuke Masaki, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   54 ( 1 )   287   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

We had been studying the synthesis of fluorine-containing polymers derived from 2,3,4,5,6-pentafluorobenzoic acid. This paper described the synthesis and characterization of novel fluorine-containing poly(arylether 1,3,4-oxadiazole)s(F-PEOs). Monomer was synthesized from hydrazine hydrate and 2,3,4,5,6-pentafluorobenzoyl chloride. F-PEOs were synthesized by nucleophilic aromatic substitution reaction at 30°C in NMP. The polymers obtained by stopping just before the gelation were all para connected linear structures confirmed by NMR. The obtained F-PEOs showed excellent solubility and afforded tough transparent films by solution casting method. They also exhibited high Tg of 157-257°C and good thermal stability, and excellent hydrophobicity due to the incorporation of 2,3,5,6-tetrafluoro-1,4-phenylene moiety.

Scopus

researchmap

Morphology control of poly(azomethine ester) by using reaction-induced oligomer phase separation

Yasuhide Yakushi, Shinichi Yamazaki, Tetsuya Uchida, Kunio Kimura

Polymer Preprints, Japan   54 ( 2 )   4777 - 4778   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

Spindle-like crystals of poly(azomethine ester) (PAME) were formed by the polymerization of 4-(4-acetoxybenzylidenamino)benzoic acid (ABBA) in liquid paraffin (LPF) at 300°C via reaction-induced crystallization of oligomers. But the trace of lamellae stacking structure was observed on the surface of crystals due to the lack of post-polymerization between the oligomers in the crystals. In order to induce the crystallization at 350°C to accelerate the post-polymerization, the polymerization of ABBA was carried out in the mixed solvent of LPF and aromatic solvent. This polymerization afforded the fibrillar crystals having smooth surface. One-pot polymerization of 4-acetoxybenzaldehyde and 4-aminobenzoic acid yielded ribbon-like PAME crystals besides spherical precipitates. These ribbon-like crystals showing the larger width than the fibrillar crystals prepared from ABBA were formed by the crystallization of oligomers through the stepwise formation of azomethine linkage and ester linkage during the elevated temperature polymerization. These crystals possessed quite high crystallinity as well as the fibrillar crystals. The morphology of PAME was controllable by means of precipitation during solution polymerization.

Scopus

researchmap

Morphology control of aromatic polyimide by using reaction-induced phase separation of oligomers

Kanji Wakabayashi, Shinichi Yamazaki, Kunio Kimura

Polymer Preprints, Japan   54 ( 1 )   599   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

We had reported that lozenge-shaped crystals and microspheres of poly(p-phenylene pyromelliteimide) were prepared by means of reaction-induced phase separation of oligomers during solution polymerization. These morphologies could be controlled on the basis of the miscibility between solvent and oligomers. In this paper, we investigated on the morphology control of Kapton by using the phase separation of oligomer during polymerization. Microspheres of Kapton were obtained in an aromatic solvent at a concentration of 3.0 wt/vol%. In contrast to this, lath-like crystals and spheres composed of plate-like crystals were obtained at a concentration of 0.5 wt/vol%. These products exhibited high crystallinity and possessed high heat-resistance. Influences of solvent and polymerization temperature on the morphology were also presented.

Scopus

researchmap

Mechanism of acceleration of growth rate under shear flow -universal role of the "oriented melt" near the surface

Kaori Watanabe, Masamichi Hikosaka, Kiyoka Okada, Akihiko Toda, Motoi Yamashita, Shinichi Yamazaki, Takashi Taniguchi, Kiyohito Koyama, Koji Yamada, Kastuhaeu Tagashira

Polymer Preprints, Japan   54 ( 1 )   626   2005年

　詳細を見る

記述言語：日本語   掲載種別：研究論文（国際会議プロシーディングス）  

We propose that shear rate γ̇ (Z) within the interface significantly increases and conformation of molecular chains will be elongated. When γ̇ (Z) becomes larger, the elongation of chains will overcome the entropic relaxation, that results in formation of the "oriented melt". Universal crystallization mechanism under shear flow is proposed that the growth rate of spherulite or shish is accelerated near the surface, that is due to formation of the oriented melt.

Scopus

researchmap

Equilibrium melting temperature of isotactic polypropylene with high tacticity: 1. Determination by differential scanning calorimetry 査読

K Yamada, M Hikosaka, A Toda, S Yamazaki, K Tagashira

MACROMOLECULES   36 ( 13 )   4790 - 4801   2003年7月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

A new method to determine the correct Gibbs-Thomson plot and equilibrium melting temperature (T-m(0)) of polymers was proposed. The Gibbs-Thomson plot method is reliable, because the Gibbs-Thomson equation is directly derived from thermodynamical relations. In this method, the heating rate dependence of melting temperature (T.) was omitted by applying the theory of the "melting kinetics", and the effect of lamellar thickening on T. was also omitted by observing thick lamellae. A differential scanning calorimeter (DSC) was used for observation of T. as a conventional method. Transmission electron microscope (TEM) was used to observe a distribution of lamellar thickness (l). It was shown theoretically that peak temperature of melting endotherm (T.(DSC)) corresponded to averaged reciprocal l (<l(-1)>) for the case of sharp distributions of T-m and l(-1). The Gibbs-Thomson plot, T-m (DSC) vs <l(-1)>, was carried out. A reliable Gibbs-Thomson plot and T-m(0) = 186.2 degreesC were obtained for a fraction of isotactic polypropylene (iPP) with high tacticity ([mmmm] = 99.6%, M-n = 64 x 10(3) and MwMn = 2.4). It was shown that DSC double melting endotherm corresponded to the number-distribution of l(-1), when lamellar thickening did not occur.

DOI： 10.1021/ma021206i

Web of Science

researchmap

Equilibrium melting temperature of isotactic polypropylene with high tacticity. 2. Determination by optical microscopy 査読

K Yamada, M Hikosaka, A Toda, S Yamazaki, K Tagashira

MACROMOLECULES   36 ( 13 )   4802 - 4812   2003年7月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

In part 1 of this series, we proposed a new method to determine the correct equilibrium melting temperature (T-m(0)). Effects of the "melting kinetics" and lamellar thickening were omitted from T-m. The correct T-m(0) of isotactic polypropylene (iPP) ([mmmm] = 99.6%, M-n = 64 x 10(3), and M-w/M-n = 2.4) was observed to be 186.1 degreesC. In this paper, the rigorous Gibbs-Thomson plot was obtained by using the direct correspondence between maximum melting temperature (T-m,T-max) and maximum lamellar thickness (l(max))- T-m,T-max and l(max) were observed by means of optical microscope and transmission electron microscope (TEM), respectively. The validity of the Gibbs-Thomson plot obtained by means of a differential scanning calorimeter (DSC) (part 1 of this series) was confirmed by comparing it with the rigorous Gibbs-Thomson plot in this paper. The Hoffman-Weeks plot is widely used as one of the methods to obtain T-m(0). It was shown that the Hoffman-Weeks plot is correct only when l proportional to 1/DeltaT where DeltaT is the degree of supercooling, is satisfied. However, in the case of iPP, the condition is not satisfied, and so the result obtained by the Gibbs-Thomson plot is not equivalent to that obtained by the Hoffman-Weeks plot. The existence of alpha2' phase was confirmed again by breakings in slopes of l and T-m against T-c at 159 degreesC. Furthermore, the broad bimodal distribution of l was caused by the difference between the lamellar thickening growth rate of isolated mother lamellae and the lamellae thickening rate of stacked daughter lamellae.

DOI： 10.1021/ma021207a

Web of Science

researchmap

Direct evidence of nucleation during the induction period of polyethylene crystallization by SAXS 査読

M Hikosaka, S Yamazaki, Wataoka, I, NC Das, K Okada, A Toda, K Inoue

JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS   B42 ( 3-4 )   847 - 865   2003年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MARCEL DEKKER INC  

Direct evidence that nuclei are formed during the induction period of crystallization is obtained for the first time by means of small-angle X-ray scattering (SAXS). Polyethylene (PE) was used as a model crystalline polymer. The nucleating agent was mixed with PE in order to increase the scattering intensity I-x from nuclei as large as 10(4) times bigger than usual. I-x increased soon after quenching to the crystallization temperature from the melt and saturated after some time. A new theory is proposed to estimate the size of the nuclei N, the number density distribution of nuclei with N at time t, f(t,N), and the induction time tau(i), by analyzing the SAXS scattering intensity. The volume-averaged size of the nuclei nearly the same as that of critical nuclei and does not change so much with time during the induction period. Lamellae start stacking much later than nuclei start forming.

DOI： 10.1081/MB-120021610

Web of Science

researchmap

Molecular weight dependence of equilibrium melting temperature and lamellar thickening of isotactic polypropylene with high tacticity 査読

K Yamada, M Hikosaka, A Toda, S Yamazaki, K Tagashira

JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS   B42 ( 3-4 )   733 - 752   2003年

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MARCEL DEKKER INC  

Molecular weight (M) dependence of the equilibrium melting temperature (T-m(o)) of isotactic polypropylene (iPP) with high tacticity ([mmmm] = 99.6%) was studied. Four fractionated iPPs with M-n = 23 x 10(3), 64 x 10(3), 94 x 10(3), and 263 x 10(3) were used. T-m(o) was obtained by using an improved method based on the Gibbs-Thomson plot proposed in previous papers. The effect of "melting kinetics" on melting temperature (T-m) was eliminated by observing isothermal melting of spherulites. The effect of lamellar thickening on Tm during T, measurement at high temperature was also eliminated by observing thick lamellae formed at high crystallization temperatures (T-c = 148 similar to 166 degreesC). With increase of M, T-m(o) increased significantly. The empirical equation, T-m(o) = 119.5 + 23.6 x log M - 2.0 x (log M)(2) (degreesC), was obtained. The molecular weight dependence of the alpha2-alpha2' transition was observed. The transition temperature (Talpha2-alpha2') also increased with increase of M. The DeltaT dependence of lamellar thickness was concluded to be controlled by that of lamellar thickening.

DOI： 10.1081/MB-120021603

Web of Science

researchmap

Nucleation and morphology of polyethylene under shear flow 査読

S Yamazaki, M Hikosaka, A Toda, Wataoka, I, K Yamada, K Tagashira

JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS   B42 ( 3-4 )   499 - 514   2003年

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MARCEL DEKKER INC  

Effect of the shear flow ((gamma)over dot = 0.5 similar to 5 s(-1)) on the nucleation and on the morphology of polyethylene (PE) during crystallization from the melt was studied by means of polarizing optical microscopy and small angle X-ray scattering. In order to analyze the results by the nucleation theory, we observed the effect of shear flow on the equilibrium melting temperature (T-m(0)). The T-m(0) under shear flow and that under quiescent state are almost the same, T-m(0) = 140.2 similar to 140.3degreesC. Therefore, the shear flow does not affect the T-m(0). The "heterogeneous" primary nucleation rate (1) and the induction onset time of nucleation (tau(onset)) of the isolated crystals under shear flow are also almost the same as those under quiescent state. The heterogeneous primary nucleation means that isolated nuclei are sporadically generating from the melt with the aid of heterogeneities such as nucleating agents. After the generation of primary nuclei, the "shish" were generated independent of the primary nucleation. We found that the shish were formed by the chain elongation caused by the velocity difference between polymer chains and dust particles, etc. After that, we observed that the "kebabs" were formed on the shish. It was found that the nucleation from the melt after melting of the "shish-kebabs" (at melt annealing temperature T-max = 160degreesC for 5 min) was accelerated compared with the ordinary melt crystallization after melting of folded chain crystals. This indicates that the "solid memory effect" of the former solid is significant. This is because of the low entanglement density within the melt of shish kebabs.

DOI： 10.1081/MB-120021578

Web of Science

researchmap

Role of Entanglement in Nucleation and ‘Melt Relaxation’ of Polyethylene 査読

Shinichi Yamazaki, Masamichi Hikosaka, Akihiko Toda, Isao Wataoka, Fangming Gu

Polymer   43 ( 24 )   6585 - 6593   2002年11月

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/S0032-3861(02)00592-X

Web of Science

researchmap

Power law of molecular weight of the nucleation rate of folded chain crystals of polyethylene 査読

SK Ghosh, M Hikosaka, A Toda, S Yamazaki, K Yamada

MACROMOLECULES   35 ( 18 )   6985 - 6991   2002年8月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

molecular weight (M.) dependence of the primary nucleation rate (I) of folded chain single crystals (FCSCs) of polyethylene (PE) was studied. A power law for the nucleation rate, I proportional to M-n (-2.4), was found. The FCSCs were formed by isothermal crystallization from the melt into an ordered phase (=orthorhombic phase). A new experimental method was established to obtain reliable I, which has been difficult in the case of heterogeneous nucleation for long years. The degree of supercooling (DeltaT) dependence of I fits well with the theoretical I given by classical nucleation theory, I = I-0 exp(-DeltaG*/kT) proportional to D exp(-C/DeltaT(2)), where I-0 is proportional to the topological diffusion coefficient of polymer chains (D), DeltaG* is the free energy for forming a critical nucleus, k is the Boltzmann constant, T is temperature, and C is a constant. It is found that DeltaG* (-C) does not depend on M., while I0 decreases with increase of M., from which it is concluded that formation of a critical nucleus is not controlled by M., while only topological diffusion of polymers is controlled by M-n, i.e., I proportional to D(M-n). Similar power laws of PE were already found by the present authors on I of extended chain single crystals (ECSCs), i.e., I proportional to M-n(-10), and on the lateral growth rates (V) of ECSCs and FCSCs, V proportional to M-n(-0.7) and V proportional to M-n(-1.0), respectively. ECSCs were formed by isothermal crystallization from the melt into a disordered phase (=hexagonal phase). Therefore, it is concluded that a common power law, I, V proportional to D(M-n) proportional to Mn-H of PE is confirmed, irrespective of nucleation or growth and irrespective of crystalline phases, ordered or disordered phases. It is to be noted that the power H depends on the degree of order of the crystalline phase, from which it is concluded that both nucleation and growth are controlled by the "topological" diffusion of polymer chains within interface between a nucleus (or crystal) and the melt and/or within the nucleus. The "topological" diffusion is related to chain sliding diffusion and disentanglements.

DOI： 10.1021/ma0105901

Web of Science

researchmap

Second-order phase transition of high isotactic polypropylene at high temperature 査読

FM Gu, M Hikosaka, A Toda, SK Ghosh, S Yamazaki, M Arakaki, K Yamada

POLYMER   43 ( 4 )   1473 - 1481   2002年2月

　詳細を見る

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCI LTD  

A second-order phase transition of alpha2 form isotactic polypropylene (iPP) is found at high annealing temperature (T-a = 159.3 degreesC) by means of X-ray diffraction method. Although the lattice shape and the space group keep the same as those of the alpha2 form, i.e. monoclinic and P2(1)/c, with increase of T-a, it has been revealed that there are discontinuous increases in the slopes of the lattice constants a and b against T-a plots, while the c and the beta keep almost constant. As a result, the slope of the unit cell volume V versus T-a plot also shows a discontinuous increase at T-a = 159.3 degreesC, indicatin- the occurrence of the second-order phase transition. In order to distinguish the two phases, the phase above the transition temperature is named alpha2' phase and the transition temperature is denoted Talpha2-alpha2'. These facts suggested that the alpha2' form is a mobile phase where the molecular chains would become loosely packed and mobile, promoting the better chain sliding diffusion. A fast lamellar thickening process has been confirmed in the higher temperature region than Talpha2-alpha2', which was reported in the precedent paper. General significance is proposed that mobile phases possibly exist at high temperature, close to the melting temperature and accelerate lamellar thickening, which improves physical properties of polymers. (C) 2001 Published by Elsevier Science Ltd.

DOI： 10.1016/S0032-3861(01)00667-X

Web of Science

researchmap

Effect of entanglement on nucleation rate of polyethylene 査読

S Yamazaki, M Hikosaka, FM Gu, SK Ghosh, M Arakaki, A Toda

POLYMER JOURNAL   33 ( 11 )   906 - 908   2001年

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC POLYMER SCIENCE JAPAN  

DOI： 10.1295/polymj.33.906

Web of Science

researchmap

C-13 NMR relaxation of poly(acrylic acid) in aqueous solution. Effects of charge density on local chain dynamics 査読

S Yamazaki, Noda, I, A Tsutsumi

POLYMER JOURNAL   32 ( 1 )   87 - 89   2000年

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

DOI： 10.1295/polymj.32.87

Web of Science

researchmap

Persistence lengths of ionenes in methanol 査読

S Yamazaki, Y Muroga, Noda, I

LANGMUIR   15 ( 12 )   4147 - 4149   1999年6月

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER CHEMICAL SOC  

To characterize the local conformations of ionenes, persistence lengths (P-1) were measured for 4,4-, and 6,6-ionenes (m,m-ionene) and 1,1-oxyethyleneionene (1,1-OEI) in methanol by small-angle X-ray scattering. It was found that P-1's of all the ionenes are almost identical (1.4 +/- 0.2 nm).

DOI： 10.1021/la981120b

Web of Science

researchmap

Chain Conformation of Aliphatic α,ω-Diamines in Aqueous Solutions 査読

Shinichi Yamazaki, Takahiro Yoshida, Yoshio Muroga, Ichiro Noda

Polymer Journal   31 ( 12 )   1237 - 1242   1999年

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/polymj.31.1237

Web of Science

researchmap

¹³C NMR Relaxation of Poly (t-butyl crotonate) in Solution. Effects of β-Substitution on Local Chain Motions 査読

Shinichi Yamazaki, Eisaku Okada, Yoshio Muroga, Ichiro Noda, Akihiro Tsutsumi

Polymer Journal   31 ( 6 )   542 - 549   1999年

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1295/polymj.31.542

Web of Science

researchmap

C-13 NMR relaxation of iso-poly(2-vinylpyridinium chloride) in aqueous solution. Effects of electrostatic interactions on local chain dynamics 査読

S Yamazaki, E Okada, Y Muroga, Noda, I, A Tsutsumi

POLYMER JOURNAL   31 ( 7 )   614 - 620   1999年

　詳細を見る

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

Measurements of C-13 spin-lattice relaxation times, T-1, and nuclear Overhauser effects, NOE, were carried out as a function of temperature at two magnetic fields for iso-poly(2-vinylpyridine) (iso-P2VP) in I,4-dioxane-d(8) and iso-poly(2-vinylpyridinium chloride) (iso-P2VPCl), in D2O to investigate the effects of electrostatic interactions on local chain dynamics. For main chain carbons of both polymers, the experimental T-1 and NOE data are in good agreement with the Dejean-Laupretre-Monnerie (DLM) model in the entire temperature range. It was found that the local conformational transitions of main chain and the libration are more restricted for iso-P2VPCl than iso-P2VP. For pyridyl ring carbons, the experimental data were reproduced by the models combining the DLM model and restricted ring rotations. The angular amplitude alpha of ring rotation of iso-P2VPCl is smaller than that of iso-P2VP. These results imply that both local motions of main chain and side chain are affected by the electrostatic interactions.

DOI： 10.1295/polymj.31.614

Web of Science

researchmap