Abstract: Poly(N-vinylcaprolactam) (PVCL) was synthesized by free-radical bulk polymerization in aqueous solution with azodiisobutyronitrile (AIBN) as initiator and N-vinylcaprolactam (VCL) as reactants. The effects of initiator and solvent dosages, reaction time and reaction temperature on polymerization of the polymer were studied. The reaction mechanism of PVCL synthesized in aqueous solution was analysed. Under the optimum reaction conditions of mass ratio of VCL:AIBN:H2O=1:0.05:15, reacting for 5 h at 75℃, the most yield of PVCL was 97%. The average molecular weight of the polymer was evaluated with gel permeation chromatography (GPC). Its structure was analyzed by infrared spectrometry (FT-IR) and nuclear magnetic resonance spectroscopy (1HNMR). The low critical solution temperature was 32℃, which was measured by spectrophotometer.

Key words: N-vinylcaprolactam, poly(N-vinylcaprolactam), free-radical polymerization, low critical solution temperature

摘要： 以乙烯己内酰胺单体(VCL)为原料，偶氮二异丁腈(AIBN)为引发剂，在水溶液中通过自由基聚合合成了聚乙烯己内酰胺. 考察了引发剂用量、溶剂用量、聚合反应时间和聚合反应温度对产物分子量和产率的影响，阐述了水溶液中自由基聚合的反应机理. 在VCL:AIBN:H2O=1:0.05:15(质量比)，75℃下反应5 h的优化工艺条件下，产率能达到97%，并通过凝胶渗透色谱仪测定了聚合物的平均分子量. 以红外光谱和核磁共振对产品结构进行了表征，用分光光度计测定其临界溶解温度为32℃.

关键词: 乙烯己内酰胺, 聚乙烯己内酰胺, 自由基聚合, 临界溶解温度