二甲基丙烯酸酯的ATRP交联聚合及交联结构均匀性

使用动态力学分析方法(DMA)对二甲基丙烯酸酯常规自由基交联聚合(CRP)和原子转移自由基交联聚合(ATRP)产物的结构进行了分析。结果表明,ATRP交联聚合可以改善交联网络均匀性;随单体双键之间链段长度的增加,交联结构更加均匀。ATRP对交联结构均匀性的改善与其聚合机理有关,初级链的同步增长以及悬挂双键的均匀分布有利于抑制微凝胶的形成,获得均匀的交联结构。

Atom Transfer Radical Crosslinking Polymerization of Dimethacrylates and Structural Homogeneities of the Crosslinked Polymers

By using dynamic mechanical analysis(DMA),crosslinking structures of polymers from conventional radical polymerization(CRP) and/or atom transfer radical polymerization(ATRP) of dimethacrylate were characterized.It is found that the ATRP of dimethacrylate can improve structural heterogeneities of the resulting networks,and with the increase of spacer length in the dimethacrylates,more homogeneous networks are observed.This improvement is attributed to the mechanism of ATRP in the crosslinking system.The reversible equilibrium between living radicals and dormant species results in a low propagation rate of the primary chains in the ATRP process and sufficient relaxation of the reactive species,which reduces the probability of microgel generation,and then benefits the equal reactions among the primary chains to form a more homogeneous crosslinking network.