混合溶剂中聚丙烯腈纺丝原液的可纺性

Spinnability of Polyacrylonitrile Spinning Solution in Composite Solvent

以二甲基亚砜/二甲基乙酰胺(DMSO/DMAc)为混合溶剂,选择高黏均分子量(Mη)聚丙烯腈(PAN)为研究对象,系统研究了温度、溶剂比例、分子量、固含量对混合溶剂纺丝原液流变性的影响。结果表明,纺丝原液的表观黏度随分子量、固含量的增大而增加,随温度升高而降低,随溶剂比例先增加后减小,在V(DMSO)∶V(DMAc)=1.25∶1处出现最小值,随后逐渐增加。PAN的结晶度随溶剂体积比增大而升高,在1.25∶1时结晶性能最优。最终实验确定PAN纺丝原液可纺性最佳条件为:纺丝温度60℃～70℃,溶剂体积比1.25:1,固含量14%～16%。

The spinnability of high molecular weight polyacrylonitrile （PAN） was investigated in the composite solvent of dimethylsulfoxide/dimethylacetamide （DMSO/DMAc）. The effect of temperature, solvent ratio, molecular weight and solid content on the rheological properties of PAN spinning solution was studied systematically. It is shown that the viscosity of the spinning solution increases with the increase of molecular weight and solid content. The viscosity drops with the increase of temperature and the DMSO ratio. There is a minimum point of viscosity then the solvent volume ratio （DMSO and DMAc） is 1.25：1. The crystallinity of PAN increases with the inerese of DMSO ratio and the best crystalline property is obtained when V（DMSO） ： V （DMAc） is 1.25 ： 1. The optimum of spinnability of PAN spinning solution was determined as follows： spinning temperature between 60 ℃ -70 ℃, V（DMSO） ： V（DMAc） of 1.25：1 and solid content of 14%--16% .