丙烯腈在1-丁基-3-甲基咪唑氯化物中的聚合及其表征

Radical Polymerization of Acrylonitrile Using 1-Buty-3-Methylimidazolium Chloride as Solvent

以离子液体1-丁基-3-甲基咪唑氯化物([bmim]Cl)为溶剂,研究了丙烯腈(AN)的自由基均聚和共聚反应,通过红外光谱(FT-IR)和核磁共振(NMR)分析了聚合产物的化学结构,研究了第二单体丙烯酸甲酯(MA)的含量对聚合反应速率及转化率的影响。结果表明:以离子液体为溶剂所得聚丙烯腈(PAN)的化学结构与在常规溶剂中的一致,聚合产物的组成比与投料比接近,分子量随着AN含量的增加而增大,反应转化率随着AN含量的增加先增大后减小,所得PAN的分子量分布窄(<1.7)、分子量高。差示扫描量热分析(DSC)结果表明:MA含量低于2%时有利于环化反应的控制。

The free radical polymerization and copolymerization of acrylonitrile （AN） in 1-buty-3-methylimidazolium chloride （[bmim]Cl） were investigated for the first time. The chemical structure of the resulting polymers were analyzed by infrared spectroscopy （FT-IR） and nuclear magnetic resonance （NMR）. The effect of AN/MA （methyl acrylate） ratio on the polymerization kinetics was discussed in detail. The chemical structures of the resulting polymers are identical with that obtained in conventional solvents. The copolymer compositions are close to the monomer feed compositions. The polymer average molecular weight increases with AN content, while there is a maximum in the monomer conversation. All the polymers show high modecular weight and narrow molecular weight distribution （〈1.7）. Differential scanning calorimetry（DSC） analysis shows that lower MA incorporation is conducive to the control of the cyclization reaction.