Decreasing the CTE of Thermoplastic Polyimide by Blending with a Thermosetting System  

作　　者：Yu-Cheng Zi Gao-Jie Wu Dong-Xu Pei Shu Guo Sheng-Li Qi Guo-Feng Tian De-Zhen Wu 

机构地区：[1]Key Laboratory of Carbon Fiber and Functional Polymers(Beijing University of Chemical Technology),Ministry of Education,Beijing 100029 China [2]Institute of Analysis and Testing,Beijing Academy of Science and Technology(Beijing Center For Physical&Chemical Analysis),Beijing 100089,China

出　　处：《Chinese Journal of Polymer Science》2023年第6期956-961,I0010,共7页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51773007);the Fundamental Research Funds for the Central Universities(No.XK1802-2)。

摘　　要：A series of thermoplastic polyimide resins with a low coefficient of thermal expansion(CTE)were prepared by blending a rigid resin system 3,3’,4,4’-biphenyltetracarboxylic dianhydride(BPDA)/p-phenylenediamine(PDA)with a flexible resin system 4,4’-[isopropylidenebis(pphenyleneoxy)]diphthalic anhydride(BPADA)/PDA.The effects of the blending ratio on the macromolecular coil size,free volume,and CTE of the mixed system were studied.The mixing is carried out in the prepolymer poly(amide acid)(PAA)stage,which makes the two systems more compatible and is conducive to the formation of a semi-interpenetrating network structure between the rigid molecular chains and flexible molecular chains.The flexible structure of the BPADA/PDA system is used to ensure the melt processing performance.The rigid characteristics of the BPDA/PDA system can inhibit the movement of molecular chains and reduce the free volume fraction,thereby reducing the CTE value.When the rigid system content reaches 30%,the CTE can be reduced to 38 ppm/K.This method provides a new approach for studying low CTE thermoplastic polyimide resins.

关 键 词：value. SYSTEM CHAINS 

分 类 号：TQ323.7[化学工程—合成树脂塑料工业]