一种长侧链取代液晶环氧单体的酸酐固化与性能

Curing Reaction and Mechanical Properties of a LC Epoxy Monomer with Long Lateral Substituent Cured with Anhydride

采用非等温差示扫描量热法(DSC)研究了一种长侧链取代液晶环氧单体与甲基六氢苯酐的固化反应历程,考察了体系的固化反应动力学特征。并通过POM、WAXD、SEM、TGA和DMA等对其等温固化产物的相结构、热性能和动态力学性能等进行表征和分析。结果表明,侧链的存在使其固化反应具有良好的可控性。固化反应活化能为77.8 kJ/mol,固化反应后期为扩散控制。液晶环氧单体经固化后呈向列相,其力学和耐热性能优良,韧性也得到明显改善。

A liquid crystalline epoxy monomer with long lateral substituent was cured with anhydride and the cure kinetics was investigated by non-isothermal DSC technique. The cured network was characterized by POM, WAXD, SEM, TGA and DMA. The results show that the long lateral substituent can greatly decreased the melting point of LC epoxy monomer. The activation energy （E,） and the frequency factor （A） calculated by Ozawa method is 77.8 kJ/mol and 1.87 × 10^9 s^-1, respectively. And the curing reaction is controlled by diffusion at the late stage of curing. A nematic structure is observed, and the mechanical properties of the LC epoxy resin is also enhanced compared to the common epoxy resins.