采用ATRP合成天然橡胶接枝共聚物——Ⅲ.NR-g-PMMA的制备

Synthesis of Graft Copolymer of Natural Rubber by ATRP Ⅲ.Preparation of NR-g-PMMA

N-溴代丁二酰亚胺与天然橡胶(NR)反应合成了大分子引发剂——溴代天然橡胶[NR-Br(1)]。通过原子转移自由基聚合(ATRP),以CuBr/PMDTA为催化体系,1引发甲基丙烯酸甲酯(MMA)接枝共聚制得新型天然橡胶-g-聚甲基丙烯酸甲酯[NR-g-PMMA(2)],其结构经1H NMR和IR表征。初步聚合反应动力学研究结果表明,NBS与NR在高温下反应容易伴随双键加成和环化反应,于室温反应所得1具有较高的引发活性;接枝聚合符合一级动力学反应,即2的分子量随MMA单体转化率的提高而增加。

An atom transfer radical polymerization（ATRP） macroinitiator,bromo-（natural rubber）1）],was synthesized by the reaction of natural rubber（NR） with N-bromosuccinimide.A novel graft copolymer,（natural rubber）-g-poly（methyl methacrylate）2）],was prepared from methyl methacrylate（MMA） using 1 as a macroinitiator and CuBr/PMDTA as the catalyst by ATRP.The structures were characterized by 1H NMR and IR.The results of preliminary study of graft copolymerization dynamics showed that the reaction of NR with NBS at high temperature easily occured addition and cyclization,1 prepared at room temperature exhibited higher initiating activity,and the graft copolymerization accorded with first-order kinetic reaction because the molecular weight of 2 increaseed as MMA monomer conversion increases.