Research Topics

Polymer materials are quite important in our daily life. What kind of polymer materials (plastics) we will develop is of cardinal importance for the solution of many environmental issues caused by the wasted plastics and energy conservation we meet now, and this answer will lead to the establishment of the decarbonized society. The mission of our research group is the contribution of not only the academic progress of polymer science but also the solution of environmental issues. Several projects are carried out as follows; Design and development of novel high-performance and functional polymeric materials by controlling morphology with molecular orientation, Development of environmental benign chemical upcycling of polymers, Synthesis and characterization of new polymers from biomass, Study on the precise polycondensation, Study on the crystallization behaviors of flexible polymers from the view point of interlocking of molecules, Improvement of mechanical performance of biodegradable polymers, and so on.

Morphology Control of Polymers by using Reaction-induced Phase Separation during Polymerization

Aromatic polymers had been expected to possess excellent thermal stability, mechanical strength, chemical resistance and so on due to the rigid structures, and therefore they have been expected as hopeful candidates for high-performance materials. Recently, they have been paid attention as functional polymers having interesting electronic properties because of the pai electron conjugated structure. However, they had been given up for applying industrial materials and devises due to their intractability also caused by the rigid structure. The excellent properties and intractability are serious antagonistic relation. In this project, the new methodology to create morphology of intractable aromatic polymers which was not influenced by the intractability of polymers has been developed by using reaction-induced phase separation during polymerization, and novel materials having unique morphology such as nanoribbon of polyimides, whiskers and dimple microspheres of biobase polyesters and hollow spheres of aromatic polyamides have been created so far. They will open the new world of attractive polymer materials.

Study on crystallization mechanism of polymers and improvement of performance of environmental benign plastics

Many of environmental benign polymers are crystalline and their performance are highly related to the crystal structure and the molecular orientation. The crystallization behavior is strongly influenced by the inter-locking and entanglement of long polymer molecules. In this project, the detail of the crystallization mechanism of polymers is studied to make the role of the inter-locking and the entanglement of molecules clearer and ultimately to improve the mechanical properties of environmental benign polymers.

Development of Novel Precise Polycondensation

PET, Nylon and many other plastics we use in our daily life are synthesized by the polycondensation. However, they cannot be precisely synthesized as well as biopolymers, and their molecular weights and their dispersity cannot be controlled, because the polycondensation reaction usually progresses according to theory of probability and the exchange reaction also occurs rapidly with the polycondensation reaction, bringing about the reshuffling the sequence regularity. In this project, the novel precise polycondensation has been developed from the viewpoint of the heterogeneous reaction-phase which is a model of nature polymerization. These developed precise polycondensations lead to the control sequence regularity of copolymerization.

Publication List

• Formation of shish-like fibril crystals from the melt of blends of cyclic and linear polyethylene under shear flow, Keiko Kobayashi, Shinichi Yamazaki, Kunio Kimura, Polymer Journal, in press, 2022, "DOI: https://doi.org/10.1038/s41428-022-00643-x
• Morphology and growth rate of spherulite of cyclic poly(ε-caprolactone) having a triazole group at the closing point, Atsushi Shinya, Ryogo Ono, Hironori Atarashi, Shinichi Yamazaki, Kunio Kimura, Polymer, Vol. 202, 122660, DOI: https://doi.org/10.1016/j.polymer.2020.122660
• Molecular weight dependence of the growth rate of spherulite of cyclic poly(ε-caprolactone) polymerized by ring expansion reaction, Ryogo Ono, Hironori Atarashi, Shinichi Yamazaki, Kunio Kimura, Polymer, Vol. 194, 122403, 2020, DOI: 10.1016/j.polymer.2020.122403
• Size control of aromatic polyamide hollow spheres prepared by reaction-induced phase separation, Hirofumi Nakayama, Naoto Adachi, Hironori Atarashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura, Polymer, Vol. 111, pp. 239-243, 2017.
• Preparation of poly(ether ketone)s derived from 2,5-furandicarboxylic acid via nucleophilic aromatic substitution polymerization, Yusuke Kanetaka, Shinichi Yamazaki, Kunio Kimura, J. Polym. Sci. Part A: Polym. Chem.,Vol. 54, No. 19, pp. 3094-3101, 2016.
• Preparation of helical crystals of aromatic poly(ester-imide) and on-off switching of helix formation, Takuya Ohnishi, Miki Nakagawa, Kanji Wakabayashi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura, Polymer, Vol. 98, pp. 378-386, 2016.
• Preparation of Poly(ether ketone)s Derived from 2,5-Furandicarboxylic Acid by Polymerization in Ionic Liquid, Yusuke Kanetaka, Shinichi Yamazaki, Kunio Kimura, Macromolecules, Vol. 49, No. 4, pp. 1252-1258, 2016.
• Preparation of poly(ester-imide) ribbons comprised of helical and non-helical blocks by copolymerization, Takuya Ohnishi, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura, RSC Advances, Vol. 6, No. 104, pp. 101995-102002, 2016.
• Hydrothermal synthesis of aromatic polyimide particles by using reaction-induced crystallization, Daisaku Shojo, Shinichi Yamazaki, Kunio Kimura, J. Polym. Sci. Part A: Polym. Chem.,Vol. 53, No. 24, pp. 2795-2799, 2015.
• Consideration on Formation Mechanism of Aromatic Polyamide Hollow Spheres prepared by Reaction-induced Phase Separation, Hirofumi Nakayama, Yuji Fujitsu, Tetsuya Uchida, Shinichi Yamazaki, Kunio Kimura, J. Polym. Sci. Part A: Polym. Chem.,Vol. 53, No. 17, pp. 1966-1974, 2015