不同分子量聚丙烯腈的制备及其高压静电纺丝研究

采用DMSO/H2O混合溶剂法制备了5种不同分子量的PAN,并以PAN为原料,DMF为溶剂,配成纺丝溶液,通过高压静电纺丝技术制备超细纤维毡(UFFM)。研究表明,相同单体组成和浓度、相同反应条件情况下,通过聚合制备PAN,随着混合溶剂中水含量的增加,生成的PAN粘均分子量相应增加,其转化率也增加。聚合所得的不同分子量PAN的热重分析显示,随着PAN分子量的增加,热重曲线的剧烈失重区会越来越明显,剧烈失重区的失重率也呈增加的趋势;高压静电纺丝研究发现,PAN-4和PAN-5纺丝溶液由于分子量过高而不可纺;另外,研究还发现,较高的纺丝电压有利于纤维直径的减小,但相应的纺丝稳定性减小,导致纤维直径分布的离散度增加。

Study on Preparation and Electrospinning of Different Molecular Weight Polyacrylonitrile

Five kinds of PAN with different molecular weight were polymerized via DMSO/H2O mixed solvent method,and the PAN was dissolved into the spinning solution with DMF as solvent and electrospun into UFFMs.The polymerization results showed that viscosity average molecular weight and conversion rate of PAN would increase with higher H2O ratio in mixed solvent at the same monomer concentration and environment conditions.From the TG analysis,dramatic weight loss zone would appear and the weight loss ratio would larger with PAN molecular weight increasing.Electrospinning results showed that the spinning solution could not be electrospun into ultra-fine fiber if the molecular weight of PAN was too high,and the higher electrospinning voltage was favorable for finer fiber diameter but cause larger dispersion of fiber diameter distribution with the electrospinning stability decreasing.