Elucidation and evolution of thermo-responsive polymers designing effector-solvent-polymer three-component systems

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01980
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 35010:Polymer chemistry-related
• Research Institution: Hokkaido University
• Principal Investigator: Kazuki Sada 北海道大学, 理学研究院, 教授 (80225911)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 温度応答性高分子 / 下限臨界共溶温度 / 高分子溶液 / 有機溶媒 / 水 / 水素結合 / コイル・グロビュール転移 / 相分離

Outline of Final Research Achievements

Using polymers with a hydrogen-bonding functional group such as an alcohol, we explored temperature-responsive phase separations with a ternary organic solvent mixtures consisting of a hydrogen-bonding good solvent and a nonpolar poor solvent. In many systems, a lower critical solution temperature (LCST) type of thermo-responsiveness was observed. This exploration of LCST-type thermo-responsive polymers with the ternary solvent system demonstrated its universality and valuable method. Furthermore, by the addition low-molecular-weight compounds with stimuli-responsive functional groups, it was possible to modulate the temperature responsiveness and give other stimulus responsivenessi. Additionally, focusing on the solvating functional groups, we successfully developed N-alkylated nylon as a novel LCST-type thermo-responsive polymer in water. These findings indicate that controlling the solvation of polymers is effective for designing the thermo-responsive polymers in any media.

Free Research Field

高分子化学

Academic Significance and Societal Importance of the Research Achievements

水素結合性官能基を持つ高分子を用いて、水素結合性の良溶媒と非極性の貧溶媒からなる三成分混合溶媒により、多くの系で下部臨界共溶温度(LCST)型の温度応答性を実現できた。このことは、この手法の普遍性の高さを示しており、同種材料の重要な設計指針になり、学術的な意義は大きい。また刺激応答性分子の添加により、容易に温度応答性の変調や刺激応答性なども可能であることを明らかにし、水中における新奇なLCST型温度応答性高分子としてN-アルキル化ナイロンの開発に成功した点はLCST型温度性高分子の可能性を広げ、応用展開が期待できる点から、社会的な意義が大きいと考えられる。