封端型低膨胀聚酰亚胺薄膜的制备及性能研究  

Preparation and Properties of End-capped Polyimide Films with Low Thermal Expansion Coefficient

作　　者：徐菁 XU Jing

机构地区：[1]上海市塑料研究所有限公司,上海201702 [2]上海计算化学与化工工程技术研究中心,上海201100

出　　处：《上海化工》2022年第5期10-14,共5页Shanghai Chemical Industry

摘　　要：以均苯四甲酸二酐(PMDA)、3,3’,4,4’-联苯四甲酸二酐(s-BPDA)为二酐单体,对苯二胺(p-PDA)、4,4’-二氨基二苯醚(ODA)为二胺单体,偏苯三酸酐(TMA)为封端剂,共聚制备了封端型聚酰亚胺(PI)浆料,并经热亚胺化得到封端型耐高温聚酰亚胺薄膜。利用傅里叶红外光谱对材料的化学结构进行了表征,研究了聚酰亚胺薄膜的热学性能和力学性能。结果表明,薄膜完全亚胺化,且末端羧基在升温过程中脱羧产生联苯键交联结构。此外,随着封端含量的增多,聚酰亚胺薄膜的耐热性能和力学性能得到改善。与未封端的聚酰亚胺薄膜相比,封端型耐高温聚酰亚胺薄膜的玻璃化转变温度上升8~15℃,1%热失重温度提高了10~24℃,而且热膨胀得到抑制,PI-8薄膜的线性热膨胀系数仅为4.16×10^(-6)/℃。End-capped polyimide films with high temperature resistance were prepared by thermal imidization of end-capped polyimide slurries, which were prepared by copolymerization with pyromellitic dianhydride(PMDA) and 3,3,4,4-biphenyltetracarboxylic dianhydride(s-BPDA) as dianhydride monomers, p-phenylenediamine(p-PDA) and 4,4-diaminodiphenyl ether(ODA) as diamine monomers, and trimellitic anhydride(TMA) as the end-capping agent. The chemical structure of the material was characterized by Fourier transform infrared spectroscopy(FTIR), and thermal and mechanical properties of polyimide films were also studied. The results show that the film is completely imidized, and terminal carboxyl groups are decarboxylated to produce a biphenyl bond crosslinked structure during the heating process. In addition, with the increase of the end-capping agent, the heat resistance and mechanical properties of polyimide films are improved. Compared with polyimide films without the end-capping agent, the glass transition temperature of end-capped polyimide films with high temperature resistance increased by 8-15 ℃, the 1% thermogravimetric temperature increased by 10-24 ℃, and the thermal expansion was inhibited. The linear thermal expansion coefficient of PI-8 film is only 4.16×10^(-6)/℃.

关 键 词：聚酰亚胺 封端 羧基 交联 高耐热 低膨胀系数 

分 类 号：TQ323.7[化学工程—合成树脂塑料工业]