可控自由聚合反应制备窄分散性聚苯乙烯大分子单体

以自制的2,2,6,6-四甲基哌啶-1-氧（TEMPO）作为稳定氮氧自由基，研究了TEMPO的存在对过氧化二苯甲酰（BPO）引发的苯乙烯聚合反应的影响。在此基础上，采用氧化-还原引发体系和自由基捕捉反应一步合成了带有羟基和2,2,6,6-四甲基哌啶-1-氧基团的新型引发剂；由此引发剂通过简易可行的可控自由基聚合反应制备了窄分散性的端羟基聚苯乙烯齐聚物，再经酯交换化反应合成了窄分散性聚苯乙烯大分子单体；最后以聚苯乙烯大分子单体和甲基丙烯酸甲酯进行共聚合反应制备了聚甲基丙烯酸甲酯接枝聚苯乙烯（PMMA-g-PS）接枝共聚物。研究结果表明端羟基聚苯乙烯齐聚物和聚苯乙烯大分子单体的分子质量分布指数为1.3左右(<1.5)，而且分子质量实测值与理论计算值能够很好地吻合,合成的聚苯乙烯大分子单体可以和甲基丙烯酸甲酯顺利进行共聚合反应合成接枝共聚物。

Synthesis of Dolystyrene Necromonomer With Narrow Distribution From Controlled Radical Polymeritation

Polymerization of styrene initiated with BPO at the presence of 2,2,6,6-tetramethyl-1-piperidinyloxy(TEMPO) was investigated .The influence of existing TEMPO to styrene polymerization initiated by BPO has been studied. Then a new functional initiator was prepared in only one-step by means of oxidation -reduction initiating system; This new initiator contains hydroxy group and TEMPO unit. Polystyrene oligomers with hydroxy group were synthesized by using this new initiator. Then polystyrene macromonomers were prepared by ester-exchange reaction from these oligomers with methacrylate. The measured molecular weight of polystyrene oligomers and polystyrene macromonomers matched well with their theoretical values. The polydispersity of the oligomers and macromonomers is less than 1.5. Macromonomer prepared can polymerize with methyl methacrylate successfuliy and PMMA-g-PS can be produced.