热处理对PBO纤维分子链结构和性能的影响

利用红外光谱分析(FTIR)、示差扫描量热法(DSC)和磷含量分析方法研究了热处理对PBO纤维结构和性能的影响。结果表明,热处理使PBO纤维分子链中聚合后期少量的未关环反应趋向完全,使得PBO分子的共轭链长增加,弱键消失,提高了PBO纤维的力学性能;提高了分子链与链之间排列的有序性,使链与链之间堆砌更加紧密,使得热处理后的纤维较难溶于MSA中;热处理使PBO纤维表面化学组成发生变化,并使其表面粗糙化,能改善其表面润湿性能;热处理对纤维强度影响甚微,提高热处理温度、延长热处理时间和增大热处理张力,能提高PBO纤维的模量。

Effect of heat treatment on molecule chain structure and performance of poly ( p-phenylene benzobisoxazole) fiber

The effects of heat treatment on molecule chain structure and performances of poly(p-phenylene benzobisoxazole) fiber were investigated by means of FTIR,DSC and phosphorus content analysis methods.The results show that heat treatment can make ring-unclosing reaction at the end of polymerization conducted fully,length of the conjugation chain increased,the mechanical performance of PBO fiber improved;heat treatment can also make ordering of molecule chain improved and build-up of molecule chain compacted,and PBO fiber dissolved difficultly in MSA.Chemical ingredients on the surface of PBO fiber after heat treatment change and its surface becomes rough;wetting property of PBO fiber surface is improved by heat treatment.Heat treatment has small effect on strength of PBO fiber,but some measures can make the modulus of PBO fiber increased,such as increasing heat treatment temperature,time and tension.