Molecular Study of Solvent Effects on Amorphous Polymer Fracture

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05631
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 35020:Polymer materials-related
• Research Institution: Nagoya University
• Principal Investigator: Fujimoto Kazushi 名古屋大学, 工学研究科, 助教 (70639301)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 全原子分子動力学計算 / 高分子破壊 / 溶媒効果

Outline of Final Research Achievements

It is known that when certain solvents interact with specific polymers, a destructive phenomenon occurs. This phenomenon, which has been observed in practical investigations, is not yet fully understood from a chemical and physical perspective. Furthermore, as this phenomenon is fundamentally molecular in nature, it necessitates research grounded in microscopic examination. In this research project, we employed all-atom molecular dynamics (AA-MD) calculations to shed light on the effects of solvents on polymer fracture at a molecular level.
We found that the yield stress of PMMA, a famous glassy polymer, decreased when exposed to methanol. A similar decrease was observed when it was exposed to water. Our AA-MD calculations suggested that this was due to increased mobility in the polymer upon contact with the liquid.

Free Research Field

物理化学

Academic Significance and Societal Importance of the Research Achievements

高分子破壊への溶媒効果はこれまで、主に高分子と溶媒の親和性で議論されてきた。メタノールはPMMAと親和性が高いため、破われやすくなるということは古くから知られていた。しかしながら、水という親和性が極めて低い溶液でもPMMAの降伏応力を低下することが実験・計算両面から明らかとなり、親和性の高低によらず液体が接触することで高分子の運動性が上昇することで破壊が起きやすくなることを分子レベルから解明した。