【摘要】 PPTA 纤维通过张力热处理,纤维的模量得到了显著的提高,纤维的分子结构及超分子结构同时发生了变化。本文测定了热处理前后的 PPTA 纤维晶胞 c 轴的变化,证实 PPTA 纤维在热处理过程中,在超分子结构变化的同时,晶胞也发生了形变。在松弛热处理过程中,纤维的晶胞 c 轴随热处理温度的升高而缩短;而在张力热处理时,晶格 c轴随张力的增犬而伸长。同时,热处理前后纤维热收缩应力的变化与 c 轴变化相对应,纤维的热收缩应力也随着张力的增加而增大,随温度的上升而降低。从热收缩应力和晶胞 c 轴的形变可以计算得到晶格热收缩模量的变化。更多还原

【Abstract】 The tensile modulus of PPTA fiber increases upon tensioned heat-set,themolecular structure and super-molecular structure of PPTA fiber are changedsimultaneously.During the relaxed heat-set,c-axis of unit cell of PPTA fiber decreases withthe increase of the heat-set temperature.However,after the tensioned heattreatment,c-axis of the unit cell was extended corresponding to the tension.Mean-while,the changes of thermal shrinking stress were proportional to the variation ofc-axis of unit cell before and after the heat treatment.From the thermal shrink-ing stress and the strain of c-axis of unit cell,we can calculate the thermalshrinking modulus of crystalline region.The thermal shrinking modulus alsoin c teased with tension and decreased with the raise of temperature.更多还原