Development of Innovative Thermal Insulator using Interfacial Resistance of Different Polymer Materials

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02083
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Saito Takushi 東京工業大学, 工学院, 准教授 (20302937)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 界面熱抵抗 / 高分子材料 / 分子動力学シミュレーション / 界面層厚さ

Outline of Final Research Achievements

The objective of this research project is to quantitatively evaluate the thermal resistance that is expected to occur at the interface of dissimilar polymer materials. The knowledge obtained will provide guidelines for the development of innovative thermal insulation materials. Two approaches were employed to quantify the interfacial thermal resistance: experimental measurement using a fabricated multilayer structure and numerical estimation by molecular dynamics simulation. Although it was difficult to determine the interfacial thermal resistance experimentally, non-equilibrium molecular dynamics simulation showed that an interfacial thermal resistance of about 1.1xE-8 m2K/W occurred in the polystyrene/polymethyl methacrylate system used. In addition, the interfacial thermal resistance was estimated to be affected by the free volume in the material, and the value of the thermal resistance was shown to vary with the thickness of the interfacial layer.

Free Research Field

伝熱工学

Academic Significance and Societal Importance of the Research Achievements

マクロスケールにおける界面熱抵抗は，材料の表面粗さによる空気層の介在が原因とされるが，近年のマイクロ・ナノ領域における熱移動現象の研究進展により，例えばシリコン等の結晶性材料と非晶質な高分子材料の界面において熱振動伝播の散乱が生じ，熱抵抗が発現することが報告されている．金属材料や高分子材料，あるいはセラミックス材料の組み合わせにおける界面熱抵抗の議論はこれまでにもあったが，モノマー種の違いによる高分子材料同士の界面熱抵抗に関する議論は本研究が初めてである．また，本研究により得られた知見は，新しいアプローチでの高分子系断熱材の開発につながる可能性があり，熱の有効利用に役立てられると考えられる．