RAFT种子乳液聚合反应初期的Monte Carlo模拟

自由基聚合是制备聚合物材料最为重要的技术 .但由于自由基极易进行双基终止 ,一般很难对其结构进行精确的控制 ,所得产物分子量宽 ,组成分布不易控制 ,很难制备嵌段共聚物 . 2 0世纪 90年代出现的活性自由基聚合技术 (RAFT)克服了上述缺点 ,成为高分子化学研究的热点1] .RAFT聚合以其适用单体广、聚合条件温和以及活性高而成为最具前途的活性自由基聚合技术之一 .迄今为止 ,RAFT的研究大多集中在溶液和本体等均相聚合体系 2～ 5] .乳液聚合有聚合速率快、环境友好、体系粘度低等优点 ,是活性自由基聚合工业化首选工艺 ,因而近年来活…

Monte Carlo Simulations for the Very Beginning of RAFT Seeded Emulsion Polymerization

Monte Carlo simulation technique was used to simulate the scenarios of the very beginning of a particle in RAFT seeded emulsion polymerization. It was first found that by introducing a high reactive RAFT agent, a large number of free radical need to be captured by the particle before polymerization starts up. The phenomenon was ascribed to the high reactivity of RAFT agent and fast exit of fragmented group of the original RAFT agent. The simulations could be successfully used to explain an unexpected long induction period and polymerization retardation reported. The results of this study will be of particular use in understanding and design of RAFT emulsion polymerization.