Investigation of the effect of surface functional group of nanofiller on the crystallization behavior of polymer nanocomposite

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15634
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35020:Polymer materials-related
• Research Institution: Kyoto University
• Principal Investigator: Hikima Yuta 京都大学, 工学研究科, 助教 (50721362)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 結晶化 / 超高速DSC / POSS / 分散性

Outline of Final Research Achievements

In this study, the crystallization behavior of polypropylene (PP) / polyhedral oligomeric silsesquioxanes (POSS) nanocomposite was investigated under the rapid cooling condition using the fast scanning calorimetry (FSC). Non-isothermal crystallization analysis revealed a unique additive effect of POSS on PP crystallization. With the cooling rate below 10 K/s, PP/POSS composites crystallized at a higher temperature than neat PP. On the other hand, the crystallization peak became broad by adding POSS with cooling rates above 10 K/s.
The crystallization kinetic analysis was conducted with isothermal FSC curves to clarify the unique additive effect of POSS. The crystallization rate constant was obtained by the Avrami model. The rate constant increased above 100℃ due to the crystal nucleating effect of POSS. Besides, the crystallization retardation effect of POSS was observed at lower temperatures.

Free Research Field

高分子結晶化，熱分析，分光分析

Academic Significance and Societal Importance of the Research Achievements

本研究ではかご型シルセスキオキサン(POSS)をポリプロピレン(PP)に添加することで，PPの結晶化の促進効果と遅延効果の両方を示すことを初めて見出した．またPOSSが温度域によって異なる添加効果を示すことにより，高速冷却時に結晶化が起こる温度範囲を高温側にも低温側にも拡張することがわかった．この結果は，結晶化開始温度を上昇させることによる結晶の緻密化と，結晶化終了温度を低下させることによる成形性の向上という相反する効果を両立するような，新たな添加剤としてPOSSが利用できる可能性があることを示唆している．