Crystallization control for constructing functional structures in polymers: flow-acceleration and topological restrictions in polymer crystallization

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K05631
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Polymer/Textile materials
• Research Institution: Yamaguchi University
• Principal Investigator: Yamamoto Takashi 山口大学, その他部局等, 名誉教授 (00127797)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 結晶化 / 高分子結晶化 / 分子シミュレーション / らせん高分子 / 流動結晶化 / トポロジー効果

Outline of Final Research Achievements

Crystallization is a process dominating structures and morphologies of every crystalline polymers. It is very fascinating to understand the emergence of crystalline order from the entangled web of macromolecules. We here adopted a very promising methodology, the computer modeling, to directly observe crystallizing polymers. We here studied polymer crystallization, both in simple linear polymers such as polyethylene and in model helical polymers such as polypropylene. By taking advantage of rapid crystallization during uniaxial stretching or shear deformation, we reexamined various aspects of crystallization in polyethylene, such as nucleation and growth, formation of network made of crystallites. On the other hand, in helical polymers, crystallization always show clear polymoprph selection of definite crystal chirality, the mechanism of which is still almost lie hidden. By use of simulations, we could successfully study chiral crystallization in helical polymers.

Free Research Field

高分子物理学、高分子計算科学

Academic Significance and Societal Importance of the Research Achievements

高分結晶化の分子機構の解明は高分子材料設計の基礎である。しかし、その分子的なメカニズムは半世紀以上にわたる努力にもかかわらず未だ大きな謎を秘めている。近年の計算機技術の飛躍的な発展を背景に、大規模な分子シミュレーションを用いてこの歴史的な課題を解決しようとする試みが世界各所でなされている。我々は、世界に先駆けてこの課題に取り組んできた。本研究では、従来の研究をさらに発展させ、より大規模系や複雑系での高分子結晶化のシミュレーションに取りくみ、典型的な繊維構造の発現機構の解明や螺旋高分子が示す特異な分子認識を伴った結晶化過程を直接的に観測することに成功した。