单体组成对甲基丙烯酸甲酯／丙烯酸丁酯RAFT共聚合转移常数的影响  

INFLUENCE OF MONOMER COMPOSITION ON THE CHAIN TRANSFER COEFFICIENT IN METHYL METHACRYLATE/BUTYL ACRYLATE RAFT COPOLYMERIZATION

作　　者：张肖娟[1] 高静[1] 罗英武[1] 李伯耿[1] 

机构地区：[1]化学工程国家重点联合实验室浙江大学化学工程与生物工程学系,杭州310027

出　　处：《高分子学报》2008年第1期83-87,共5页Acta Polymerica Sinica

基　　金：教育部“新世纪优秀人才计划”;国家自然科学基金(基金号20774087)资助项目

摘　　要：采用Z基团为—CH2C6H5的RAFT试剂为链转移剂,AIBN为引发剂,60℃下进行甲基丙烯酸甲酯/丙烯酸丁酯(MMA/BA)的本体RAFT共聚合,并用GPC法测算不同单体组成下低聚物RAFT的链转移常数(Ctr).实验表明,对BA的均聚合,Ctr高达116,但对MMA的均聚合,Ctr约为0.1.在共聚体系中,Ctr与fMMA之间为非线性关系,随着fMMA的增加呈下降趋势.Ctr随单体组成的变化规律可以很好地解释不同单体组成下RAFT共聚合中分子量及其分布随转化率变化的规律.The bulk copolymerization of butyl acrylate （BA） and methyl methacrylate （MMA） in the presence ofthe RAFT agent with Z =—CH2 C6H5 and 2,2′-Azobis（isobutyronitrile） （AIBN） as an initiator was carried out at 60℃ .The chain transfer coefficients （Ctr） at different monomer compositions were determined by the GPC peak resolution method. In the BA homopolymerization, Ctr was up to 116 while it was about 0.1 in the MMA homopolymerization. Since Ctr was too low, the homopolymerization of MMA mediated by the RAFT agent was out ofcontrol. In the copolymerization systems, Ctr showed a nonlinear decrease with the increasing of MMA compositions. When a small fraction with PDI around 1.2 of BA was added at the end of the to an MMA polymerization system, the polymerization became well controlled polymerization. The changing trend of Ctr with monomer compositions wellexplained the profiles of the molecular weight and its distribution against conversion with different monomer compositions.

关 键 词：RAFT共聚 链转移常数 分子量 分子量分布 

分 类 号：TQ316.3[化学工程—高聚物工业]