紫外光引发醋酸乙烯酯溶液聚合研究

采用二苯甲酮(BP)为光引发剂，三乙胺(TEA)为共引发剂，不同溶剂(环己酮，四氢呋喃)进行紫外光溶液聚合反应合成了一系列聚醋酸乙烯酯(PVAc)，考察了聚合温度、聚合时间、引发剂、共引发剂和单体浓度等对单体的转化率和聚醋酸乙烯酯相对分子质量等的影响。实验结果显示在四氢呋喃体系中温度对转化率的影响较大，且在相同的条件下转化率也较环己酮体系高。对两种溶液聚合体系，从聚合反应机理分析了相对分子质量较低且随引发剂、共引发剂的变化而改变很小的原因。

UV initiated solution polymerization of vinyl acetate

Poly (vinyl acetate) was synthesized via UV photopolymerization, with BP as photoinitiator, triethylamine as hydrogen contributor, tetrahydrofuran and cyclohexanone as solvents, respectively. The principal factors affecting the photopolymerization, including time, temperature, photoinitiator and co initiator concentration, and monomer concentration, were studied systematically. The results show that the effect of temperature on monomer conversion in cyclohexanone is more distinct than that in tetrahydrofuran. The effects of co initiator concentration in different polymerization systems are similar, that is, the higher the concentration is, the higher monomer conversion is, while lower PVAc molecular weight is. In the two polymerization systems, high monomer concentration leads to a high monomer conversion and PVAc molecular weight. The products were characterized by GPC, and the mechanism of this photopolymerization in two different solvents was also discussed.