甲基丙烯酸甲酯常规自由基聚合研究

Free radical polymerization of MMA initiated by BPO

以过氧化二苯甲酰(BPO)为引发剂,研究甲基丙烯酸甲酯的常规自由基聚合。结果表明:温度、引发剂浓度、单体浓度对聚甲基丙烯酸甲酯(PMMA)相对分子质量的影响与经典自由基聚合反应理论完全吻合。升高温度、提高引发剂浓度、引入溶剂都将使PMMA相对分子质量下降。BPO分解生成的苯甲酰初级自由基不但引发单体聚合,还发生了脱羧反应生成苯自由基,苯甲酰初级自由基与链自由基会发生初级终止反应;引发剂浓度对脱羧反应的影响较小,反应温度和单体浓度对脱羧反应的影响较为明显。升高反应温度、提高引发剂浓度等有利于链自由基的双基终止反应。

The free radical polymerization of methyl methacrylate initiated by benzoyl peroxide(BPO)was studied.The results show that the effects of temperature,initiator concentration and monomer conentration on relative molecular mass of poly(methyl methacrylate)(PMMA)fit well with the classical theory.The relative molecular mass of PMMA decreases with the increase of initiator concentration and polymerization temperature,as well as the introduction of solvent.The benzoyl primary radical resolved from BPO not only initiates monomer polymerization,but also produces benzene radical via decarboxylation,then benzoyl radical reacts with chain radical for primary termination reaction.The initiator concentration has little effect on decarboxylation,while reaction temperature and monomer concentration contribute much to decarboxylation.It is beneficial for double base termination reaction by improving the reaction temperature and initiator concentration.