连续搅拌釜合成聚丙烯腈的聚合工艺

研究了中试规模的连续搅拌釜内丙烯腈/丙烯酸甲酯/衣糠酸(AN/MA/IA)三元水相沉淀聚合,考察了反应停留时间、引发剂用量和搅拌速度对聚合反应和共聚物性能的影响。研究发现,适当延长停留时间有助于提高颗粒聚集稳定性,减小产物中共聚组成与单体投料比的差距。较长停留时间适合采用较高的搅拌转速,有利于提高反应体系的空间均匀性,减小共聚物相对分子质量分布宽度。在进料单体浓度一定的情况下,引发剂用量不宜过低,可以控制较高的反应转化率和较低的相对分子质量分布宽度,由此获得共聚组成理想且热环化性能较好的聚丙烯腈。

Polymerization of Acrylonitrile Copolymer by Continuous Stirring Reactor

This paper studied acrylonitrile/methyl acrylate/itaconic acid ternary aqueous precipitation polymerization in a continuous stirring reactor of middle scale,and investigated the effects of reaction time,initiator dosage and stirring speed on the polymerization reaction and copolymer property.It is found that the appropriate increase of reaction time can improve particle stability and decrease the difference between copolymer composition and monomer feeding ratio.A fast stirring speed is suitable for a long reaction time,which is beneficial to improve the spatial uniformity and reduce the polydispersity index of molecular weight.Meanwhile,the initiator dosage should not be too low under a certain monomer feeding concentration,which can effectively control the conversation and distribution of molecular weight,in order to obtain polyacrylonitrile with ideal composition and thermal circuiting performance.