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研究了以苯乙烯(St)和N-[4-(2-溴丙酰氧基)苯基]马来酰亚胺(BPPM)的交替共聚物P(St-alt-BPPM)为大分子多官能度引发剂,以CuBr/2,2’-联吡啶(bpy)为催化体系,环己酮为溶剂,在60或80℃下进行St的原子转移自由基聚合(ATRP).结果表明,反应呈现活性聚合的假一级反应动力学特征,聚合物分子量随着单体转化率上升而增加,降低反应温度将减低反应速率,但是所得聚合物[P(St-alt-BPPM)-g-PS]分子量分布更窄.水解实验证明该过程具有一定可控性.由于类似的单官能度引发剂无法在同等条件下顺利引发St的ATRP,因此采用大分子多官能度引发剂可以大幅度降低ATRP的反应温度.此加速现象被归因于CuBr/bpy从大分子引发剂线团外向线团内扩散,而CuBr2/bpy则从大分子引发剂线团内向线团外扩散,从而提高大分子引发剂线团中的自由基浓度和聚合反应速率.
The copolymer (St-alt-BPPM) of styrene (St) and N- [4- (2-bromopropionyloxy) phenyl] maleimide (BPPM) The functional initiator was CuBr / 2,2’-dipyridyl (bpy) catalyzed system and cyclohexanone was used as the solvent to carry out atom transfer radical polymerization (ATRP) of St at 60 or 80 ° C. The results showed that the reaction The pseudo-first-order kinetics of living polymerization showed that the molecular weight of the polymer increased with the increase of the monomer conversion. Decreasing the reaction temperature decreased the reaction rate. However, the polymer [P (St-alt-BPPM) ] Narrower molecular weight distribution.Hydrolysis experiments show that the process has a certain controllability.Because similar monofunctional initiator can not be successfully under the same conditions ATRP St, so the use of macromolecular polyfunctional initiator can significantly reduce the ATRP The acceleration is attributed to the diffusion of CuBr / bpy from the extrinsic filament of the macromolecular initiator thread and to the diffusion of CuBr2 / bpy from the inside of the macromolecular initiator thread, thereby increasing the macromolecular priming Free radical concentration and polymerization rate in the dough.