沸水再拉伸速率对聚丙烯腈纤维结构与性能的影响

以1-丁基-3-甲基咪唑氯盐(BMIM]Cl)为溶剂溶解聚丙烯腈(PAN)制成PAN纺丝原液,采用干喷湿法纺丝,经过凝固、预拉伸、沸水拉伸制得PAN纤维,对所得PAN纤维进行沸水再拉伸处理,研究了沸水再拉伸速率对PAN纤维结构和性能的影响。结果表明:PAN纤维中残留质量分数为4.38%的离子液体,为沸水再拉伸起到了增塑作用;随着沸水再拉伸速率的增大,PAN纤维的力学性能提高,断裂强度由2.69cN/dtex提高到4.33 cN/dtex,而断裂伸长率由26%减小到20%,纤维的玻璃化转变温度、晶区取向度、双折射率、结晶度、晶粒尺寸均增大。

Effect of secondary drawing rate in boiling water on structure and properties of polyacrylonitrile fiber

A polyacrylonitrile(PAN) fiber was prepared via dry-jet wet spinning process from the spinning solution of PAN dissolving in 1-butyl-3-methylimidazolium chloride(Cl) after coagulation,pre-drawing and drawing in boiling water.The obtained PAN fiber was subject to the secondary drawing in boiling water.The effect of the secondary drawing rate in boiling water on the structure and properties of polyacrylonitrile fiber was studied.The results showed that the residual ionic liquid of 4.38% by mass fraction in the fiber provided a plasticization effect during the secondary drawing in boiling water;and the mechanical properties of PAN fiber were improved,the breaking strength was increased from 2.69 cN/dtex to 4.33 cN/dtex,the elongation at break was decreased to 20% from 26%,and the glass transition temperature,crystalline orientation,birefringence,crystallinity and crystal size were all increased while raising the secondary drawing rate in boiling water.