EVA接枝α—Ms的研究

A Study of the Graft Copolymerization of α-Ms onto EVA

本文以K_2S_2O_8-NaHSO_3为引发剂,在氮气保护下通过乳液聚合研究了EVA与α-Ms的接技共聚,讨论了各种因素对单体转化率和接枝效率的影响.结果表明:随着反应时间的增加单体转化率和接枝效率先增加,后下降在反应曲线图上均出现一峰值;引发剂用量增加单体转化率逐渐增大,而在接枝效率的变化曲线图上出现一峰值;乳化剂用量增加,转化率和接枝效率均升高;温度对转化率和接枝效率的曲线图上均出现一峰值,但温度低于303K时单体只能自聚不能接枝;随着单体用量的增加,转化率降低,接枝效率升高,接枝物玻璃化温度也升高;EVA和接枝产物的电镜分析表明两者有明显差异,接枝产物中EVA表面确已形成微观接枝点.本研究找出了EVA接枝α-Ms的最佳反应条件,为工业化生产提供了依据.

The graft copolymerization of α-Ms onto EVA by emulsion polymerization under N2 atmosphere, with K2O2O8-NaHSO3 as initiator, was studied, and the effect of different factors on the monomer conversion efficiency and graft efficiency were also studied in this paper. The results showed that the conversion and graft efficiencies increased first and then decreased with the increase of reaction time, having a peak on the reaction curve; when the initiator content increased, the conversion efficiency increased, and there was a peak on the curve of graft efficiency vs initiator content; the convernsion and graft efficiencies increased with the increase of the emulsifier content; on the curves of conversion and graft efficiencies vs reaction temperature there was a peak respectively, but the monomer could only self-polymerized when the temperature was lower than 303 K; the conversion efficiency decreased, graft efficiency increased and the Tg of the graft copolymer increased when the monomer content increased; the obvious difference on the SEM of EVA and the graft copolymer showed that micro scopic graft points formed on the surface of EVA. An optimum reaction condition for the graft copolymerization of a-MS onto EVA was found and a reference for the industrial production of the copolymer was also given in this paper.