热处理工艺对三元共聚聚酰亚胺纤维结构和性能的影响

Effects of heat treatment process on the structure and properties of co-polyimide fibers

采用傅立叶红外光谱(FTIR)、扫描电子显微镜(SEM)、声速取向、热重分析仪(TGA)等表征手段研究了热处理对湿法纺丝制备的3,3',4,4'—二苯酮四酸二酐(BTDA)—二异氰酸甲苯酯(TDI)/二异氰酸二苯甲烷酯(MDI)三元共聚聚酰亚胺纤维结构与性能的影响。结果表明:热处理对纤维结构无明显影响;热处理使纤维表面更加致密,提高了纤维的取向度;与初生纤维相比,热处理之后纤维力学性能提高了近3倍,模量提高了2倍,同时热稳定性能得到了增强。

The effects of heat treatment process on the structure and properties of the 3,3＇, 4,4＇-benzophenone tetracarboxylic dianhydrid （BTDA）-toluene di-isocyanate （TDI）/diphenyl- methylene di-isocyanate （MDI） co- polyimide fiber via wet spinning method were studied by using FTIR, SEM, sonic orientation, thermo gravimetric analyzer（TGA）and other testing methods. The results showed that the chemical structure of PI fiber had no evident change after being heat treated. The surface of fiber became.more solid and the degree of orientation of PI fiber also increased. The heat treatment had a great effect on the mechanical properties of PI fiber for its breaking strength increasing at 3 times and initial modulus at 2 times. The thermal stability of PI fibers also enhanced.