温度对TBTGA为链转移剂的RAFT聚合制备PMMA相对分子质量的影响

Effect of temperature on relative molecular mass of PMMA prepared by RAFT with TBTGA as chain transfer agent

以2-巯基-S-硫代苯甲酰乙酸为链转移剂,与高活性单体甲基丙烯酸甲酯发生可逆加成-断裂链转移自由基聚合制备聚甲基丙烯酸甲酯(PMMA),探究温度对聚合的影响。结果表明:反应速率常数和链转移常数随温度升高而增大,即升温有利于链转移;当反应温度为80℃时,PMMA的相对分子质量与理论值相差较小,且相对分子质量分布较窄。

High-activity monomer methyl methacrylate(MMA)was used to prepare poly(methyl methacrylate)(PMMA)with 2-mercapto-S-(thiobenzoyl)thioglycolic acid(TBTGA)as chain transfer agent via reversible addition-fragmentation chain transfer(RAFT)polymerization.The effect of temperature on RAFT polymerization of MMA with TBTGA as chain transfer agent was investigated.The results show that the rate constant of reaction and the constant of chain transfer are increased with the increase of temperature,so the increase in temperature is in favor of the rate of chain transfer.The relative molecular mass of PMMA is close to the theoretical value and the relative molecular mass distribution is relatively narrow at 80℃.