含氯聚对苯二甲酰对苯二胺纤维的结构与性能

Structure and properties of chlorinated poly( p-phenylene terephthalamide) fiber

以邻氯对苯二胺(Cl-PPD)与对苯二甲酰氯(TPC)为单体,在N-甲基吡咯烷酮(NMP)/氯化钙(Ca Cl2)或氯化锂(Li Cl)体系中进行低温溶液聚合,合成了含氯聚对苯二甲酰对苯二胺(Cl-PPTA)溶液,直接进行湿法纺丝,制备了Cl-PPTA纤维。采用旋转流变仪测试了Cl-PPTA溶液的流变性能,利用傅里叶变换红外光谱、扫描电子显微镜、热失重分析、纤维强伸度仪、声速取向测量仪、氧指数测定仪对Cl-PPTA纤维的结构及性能进行了表征。结果表明:相比于NMP/Ca Cl2体系,NMP/Li Cl体系的Cl-PPTA溶液黏度更低,所制得的纤维其表面更光滑、结构更致密,纤维力学性能也较好;热处理后两种纤维力学性能均得到进一步改善;两种Cl-PPTA纤维具有较好的热稳定性,其阻燃性能均远高于PPTA纤维。

Chlorinated poly（ p -phenylene terephthalamide） （Cl-PPTA） solution was synthesized by using 2-chloro-p -pheny- lenediamine （Cl-PPD） and terephthalyl chloride （TPC） as monomers in the solution systems of N-methyl pyrrolidone （NMP）/ calcium chloride （ CaCl2 ） and NMP/lithium chloride （LiC1） via low-temperature solution polymerization, which was directly pro-duced into Cl-PPTA fibers via wet spinning. The rheological behavior of the Cl-PPTA solution was measured with a rotary rheometer. And the structure and properties of the produced Cl-PPTA fibers were characterized by Fourier transform infrared spectrometry, scanning electron microscopy, thermogravimetric analysis, tensile test, sonic orientation test, limit oxygen index test. The results showed that the CI-PPTA solution from NMP/LiCl system generated the fiber with smoother surface, denser structure and better mechanical properties due to its lower viscosity as compared to NMP/CaCl2 system; the mechanical properties of the fibers prepared from the two solution systems were both improved after heat treatment; and both of the Cl-PPTA fibers bad favorable thermal stability and the flame retardance extremely higher than that of PPTA fiber.