Effect of slow cooling temperature on structure and properties of PPS fibers

Since the brittleness of polyphenylene sulfide(PPS) affects its spinnability,an additional slow cooling device was installed on the spinning machine so as to change the state of aggregation structure and improve the toughness of PPS fibers.The effect of slow cooling temperature on the structure and properties of PPS fibers is studied.The results showed that the slow cooling temperature has a greater impact on the crystallinity of the PPS fiber,to be specific,with the increase of slow cooling temperature,PPS UDY crystallinity decreased by 29.8%;but the crystallinity of PPS DT increased with by 12.0%;increasing the slow cooling temperature decreased the orientation degree of UDY gradually by 7.8%,but increased the orientation degree of DT yarn gradually by 15.3%,however,it began to decrease when the temperature reached 175 ℃;with an increase in slow cooling temperature,the breaking strength of PPS DT yarn increased gradually with maximum margin of 9.9% and it began to decrease at 175 ℃,but the breaking elongation had the opposite trend,the largest decline was 31.2%;as the slow cooling temperature increased,the drying shrinkage of the PPS fibers reduced gradually,the largest drop was 46.6%,when the temperature was over 175 ℃,the drying shrinkage began to increase;and the initial modulus increased gradually with maximum margin of 12.7% as the slow cooling temperature increased.