AIBN/SmCl3/乳酸体系催化甲基丙烯酸甲酯的反向原子转移自由基聚合

利用稀土金属化合物三氯化钐(SmCl3)和二氯化钐(SmCl2)之间的单电子转移反应,以AIBN/SmCl3/乳酸作为反向原子转移自由基聚合(ReverseATRP)的催化体系,成功地实现了甲基丙烯酸甲酯(MMA)的反向ATRP,并考察了温度、溶剂和组分比对聚合反应的影响.MMA在该体系中的聚合反应是一级反应,所得PMMA的分子量与单体转化率成正比,聚合物的分子量分布较窄(Mw/Mn<1.5),具有活性聚合的特征.

Reverse ATRP of MMA Catalyzed by AIBN/SmCl3/Lactic Acid System

Reverse ATRP of methyl methacrylate(MMA) mediated by AIBN/SmCl3/lactic acid system was investigated.The one electron transfer reaction of SmCl3 to SmCl2 was firstly employed for living/controlled radical polymerization successfully.The kinetics study indicates that the polymerization is first order in monomer concentration.Moreover,the number average molecular weight(M-n) increased linearly with the monomer conversion,and the molecular weight distributions were narrower(less than 1.5).These show that the polymerization of MMA is a living/controlled one in the above system.The effects of different reaction conditions,such as solvent sort,temperature and ratio of 0/0/0,on the polymerization were studied.PMMA with narrower molecular weight distribution were obtained in DMF at 80℃.Furthermore,the apparent activation energy E-app=74.1 kJ/mol was calculated for the reverse ATRP of MMA initiated by AIBN/SmCl3/lactic acid.