摘要：本文介绍了合成两种链转移剂—S,S'-二(α,α'-二甲基-α"-乙酸) 三硫代碳酸酯(TTX)和 S-1-十二烷基-S'-(α,α'-二甲基-α"-乙酸)三硫代碳酸酯(TTC)的方法，并将其运用于甲基丙烯酸甲酯和苯乙烯的自由基聚合中来表征其链转移活性，并以甲基丙烯酸甲酯和苯乙烯为第二单体进行扩链反应。结果表明甲基丙烯酸甲酯的聚合过程并不是RAFT聚合，而苯乙烯的聚合过程则体现出很好的活性聚合特点，并且证明一级聚苯乙烯大分子具有活性末端。分析原因为所合成链转移剂在甲基丙烯酸甲酯中链转移常数太小。

    通过苯乙烯的RAFT聚合过程，证明了所合成的两种链转移剂都有链转移能力。

关键词：链转移剂；可逆加成-断裂链转移自由基聚合(RAFT)；甲基丙烯酸甲酯(MMA)；苯乙烯(St)；扩链

Abstract：This dissertation introduced the synthesis methods of two chain transfer agents:S,S'-Bis(R,R'-dimethyl-R"-aceticacid)-trithiocarbonate(TTX) and S-1-Dodecyl-S'- (R,R'-dimethyl-R"-acetic acid) trithiocarbonate(TTC), and its applications in free radical polymerization of methyl methacrylate (MMA) and styrene (St) to represent the chain transfer activity, then used MMA and St as the second monomer for chain extension. The results showed that, the polymerization process of MMA was not RAFT, however, the polymerization processof St reflected characteristics of living polymerization. It proved that the first polystyrene macromolecule had the active end group. Analysed the reason, the chain transfer agent in MMA had the lower chain transfer number.

  Through the RAFT process of St,it proved that the two chain transfer agents both had the activaty of chain transfer.

Key words: chain trainsfer agent; reversible addition-fragmentation transfer(RAFT); methyl methacrylate (MMA); styrene (St); chain extension