叔胺中的取代基团对其促进烯类聚合活性的影响

<正> 过硫酸盐和水溶性脂肪胺可以组成引发体系用于烯类聚合反应。脂肪胺的促进聚合活性随其结构不同而异。为了研究清楚脂肪胺促进聚合活性与结构的关系,本文合成了几种甲基取代的脂肪叔胺,分别与过硫酸盐组成引发体系用于烯类聚合反应。研究结果表明,甲基取代基团的效果较好。

EFFECTS OF TERTIARY ALIPHATIC AMINES ON PROMOTING ACTIVITIES IN VINYL POLYMERIZATION

Tertiary aliphatic amines containing methyl substituents on the nitrogen atom such as N-methyl diethylamine, N-methyl di-n-propylamine, N,N-dimethyl n-propylamine, N-methyl di-n-butylamine, N,N-dimethyl n-butylamine and the other trialkyl amines such as triethylamine, tri-n-propylamine, tri-n-butylamine were coupled with persulfate as redox initiators in acry-lamide polymerization. The rate of polymerization and the over all-activation energies of polymerization were determined respectively. It was found that the tertiary aliphatic amines containing methyl substituents exhibited higher promorting activities in polymerization of acryla-mide than those of trialkyl amines with larger alkyl substituents. The results of spin trapping and ESR spectroscopy study showed that the tertiary amines having methyl substituents were oxidized by persulfate to form the corresponding dialkylamino methyl free radicals and they were responsible for initiating of vinyl polymerization and became the amino end groups of the resulting polymers as confirmed by end group analysis.