A novel strategy to branched polyacrylonitrile via one‐pot RAFT copolymerization of acrylonitrile and an asymmetrical divinyl monomer
A novel strategy to branched polyacrylonitrile via one‐pot RAFT copolymerization of acrylonitrile and an asymmetrical divinyl monomer
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DOI：
10.1002/app.30599
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发表时间：
2009-10
影响因子：
3
通讯作者：
Xiao-hui Liu;Guibao Zhang;Baixiang Li;Yungang Bai
中科院分区：
文献类型：
--
作者：
Xiao-hui Liu;Guibao Zhang;Baixiang Li;Yungang Bai
通过丙烯腈和一种不对称二乙烯基单体（甲基丙烯酸烯丙酯）的一锅自由基共聚制备了支化聚丙烯腈。RAFT技术用于通过快速可逆链转移平衡保持低增长链浓度，从而防止交联，直到高水平的单体转化率。这种新的策略被证明产生具有丰富的侧链官能乙烯基和腈基的支化结构，以及作为受控/活性自由基聚合特性的行为的受控分子量。详细研究了温度、支化剂与单体的摩尔比、链转移剂与引发剂的摩尔比等实验参数对控制分子尺寸（分子量和多分散指数）和支化度的影响。此外，1H-1 NMR和凝胶渗透色谱法证实了所得聚合物的支化结构。共聚物的特性粘度也低于线性对应物。
Branched polyacrylonitriles were prepared via the one-pot radical copolymerization of acrylonitirle and an asymmetric divinyl monomer (allyl methacrylate) that possesses both a higher reactive methacrylate and a lower reactive allyl. RAFT technique was used to keep a low-propagation chain concentration via a fast reversible chain transfer euilibration and thus the cross-linking was prevented until a high level of monomer conversions. This novel strategy was demonstrated to engenerate a branched architecture with abundant pendant functional vinyl and nitrile groups, and controlled molecular weight as a behavior of controlled/living radical polymerization characteristics. The effect of the various experimental parameters, including temperature, brancher to monomer molar ratio, and chain transfer agent to initiator molar ratio, on the control Of moleculer dimension (molecular weight and polydispersity indices) and the degree of branching were investigated in detail. Moreover, H-1 NMR and gel permeation chromatography confirm the branched architecture of the resultant polymer. The intrinsic viscosity of the copolymer is also lower than the linear counterpart.