Modification of mechanical properties of PMMA/salt samples based on water absorbenc

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14680
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35020:Polymer materials-related
• Research Institution: Kanazawa University
• Principal Investigator: Ito Asae 金沢大学, フロンティア工学系, 准教授 (20845177)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 非平衡構成方程式 / ガラス状高分子 / 水 / PMMA / 塩

Outline of Final Research Achievements

We have also found to control the water contents in the salt-doped PMMA samples by changing the salt amounts. The brittle-to-ductile transition was appeared in the mechanical properties. We have proposed a constitutive equation, which was developed for the stress-strain curves of PMMA/Li-salt samples. Here, the water spots were formed surrounding the salts. The water spots accumulated around salts were spread throughout a whole sample specimen and stretched to a homogeneously water absorbed condition. The non-equilibrium constitutive equation was introduced in which the fraction α of PMMA including in the constitutive equation and α changed with strain with the constant k as an exponent. The analysis showed that the constant k does not depend on the salt concentration, but only on the amount of water. We have performed experiments with different salt species.

Free Research Field

高分子物理、レオロジー

Academic Significance and Societal Importance of the Research Achievements

近年、環境・エネルギー問題対策として、システムの軽量化を目的にさまざまな分野で無機材料のポリマー系材料への置き換えが進んでいる。ガラス状ポリマーは透明性が高く、無機ガラスの代替が期待されるが、硬さと粘り強さの両立が難しかった。さらに、最近では資源の有効利用を目指し、サステイナブルな材料創
成が求められている。そこで申請者は、代表的なガラス状ポリマーで最も高い透明性を持つポリメタクリル酸メチル（PMMA）を用いて、持続可能な方法で硬さを保ったまま粘り強さを付与できる材料設計指針を確立し、資源循環型社会に寄与する「力学特性制御により硬さと粘り強さの両立を実現した革新的ガラス状ポリマー」を創出する。