聚丙烯腈预拉伸丝的热塑拉伸特性

Thermal tensile property of pre-drawn acrylic filament

通过湿法纺丝制备了不同拉伸倍数的聚丙烯腈预拉伸丝,采用偏光显微镜观察了拉伸倍数对预拉伸丝横截面形态的影响,采用DMA研究了预拉伸丝的塑化温度。在此基础上,采用温度控制的应力-应变仪研究了聚丙烯腈预拉伸丝的断裂应力和断裂伸长与温度、预拉伸倍数的关系,发现聚丙烯腈预拉伸丝在室温下的断裂伸长率小于40%,当二次拉伸的温度超过100℃时,断裂伸长率明显增大;且纤维的断裂应力随着预拉伸倍数的增大而增大。对预拉伸纤维进行二次热塑拉伸,发现纤维强度的增大程度大于水浴拉伸。

Pre - drawn acrylic filaments of different draw ratioes were prepared by use of wet - spinning technology. The cross - section morphology of pre - drawn filaments was observed by polar - light microscope. The ductility temperature was analyzed with DMA. The relationship between the breaking stress and strain of pre - drawn acrylic filament against the temperature and pre - drawn ratio was investigated by temperature - controlled stress - strain meter. It shows that the breaking elongation of pre - drawn acrylic filament is less than 40% at room temperature, and the breaking elongation is increased when the temperature is higher than 100℃. The breaking stress is increased with the pre - drawn ratio. The strength of the filament is largely during the second - stage ductile draw process compared to the draw process in boihng water.