聚苯硫醚纤维的抗张强度与工艺和结构的关系

以熔融纺丝法制备出不同结晶度的各向同性聚苯硫醚纤维作为样品,根据密度和声速测定值确定出PPS晶相和无定形相的本征横向声模量E0⊥,c(4.40 GPa)和E0⊥,am(1.99 GPa).利用密度梯度法测定出的结晶度Xc和X-衍射法测定的晶区取向因子fc,按照Samules模型计算出不同牵伸和定型工艺下制备的PPS纤维样品的非晶区取向因子(fam),在此基础上分析PPS纤维抗张强度与牵伸定型工艺参数、结构之间的关系.结果表明,PPS纤维的最佳牵伸温度及紧张热定型温度分别在90℃和190℃附近;提高PPS纤维的牵伸温度及紧张热定型温度可以增加纤维的结晶度,在一定范围内对纤维抗张强度的增加有促进作用;但较高的牵伸温度及紧张热定型温度不利于纤维非晶区取向的提高,造成PPS纤维抗张强度降低.牵伸倍数的增加可以有效提高PPS纤维的非晶区取向程度,抗张强度也随着增加.

THE RELATIONSHIP AMONG TENACITY, PROCESSING AND STRUCTURE OF POLY(PHENYLENE SULFIDE) FIBERS

Non-oriented poly(phenylene sulfide) fibers with different crystallinity were prepared by melt spinning and heat treating.Based on the measurement of density and sonic velocity,intrinsic horizontal sonic modulus of amorphous and crystalline phases of PPS fibers was determined to be 1.99 GPa and 4.40 GPa,respectively.Based on Samules’s model and measured crystallinity and X-ray azimuth scanning,the Hermans orientation factor of amorphous phase of PPS fibers made at different drawing and heat-setting conditions was determined.The relationship between tenacity and processing conditions was discussed based on the above structure parameters.The work shows that the optimum stretching and setting temperature of PPS fiber is near 90℃ and 190℃ separately.The increasing of stretching and tense setting temperature is beneficial to the improvement of the fiber’s crystallinity and is helpful to the promotion of fiber’s tenacity within certain range.But the over rising of the processing temperature will be disadvantageous to fiber’s amorphous orientation and thus reduce the tenacity.The increasing of stretching multiples will improve the amorphous orientation of the fiber and furthermore improve the tenacity of the fiber.