中文摘要：

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一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。

英文摘要：

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.