中文摘要：

对甲基丙烯酸聚乙二醇单醚酯/二甲基丙烯酸聚乙二醇酯共聚体系分别实施常规自由基聚合（FRP）,原子转移自由基聚合（ATRP）和可逆加成-断裂链转移（RAFT）自由基聚合,通过观察聚合速率、双键转化率、凝胶点以及交联网络的发展,比较FRP、ATRP和RAFT共聚合体系的反应动力学和交联行为。3个聚合体系均出现了自加速现象,ATRP体系的自加速由扩散控制的自由基脱活造成,RAFT体系的自加速来自于扩散控制的自由基加成。在ATRP和RAFT交联体系中,初级链的缓慢增长和充分松弛减少了分子内环化,抑制了微凝胶形成,因此其凝胶点远低于FRP体系。ATRP和RAFT交联网络通过凝胶自由基与单体加成以及支化链的结合而不断发展,导致凝胶含量和交联网络密度随转化率不断增大。

英文摘要：

Atom transfer radical polymerization （ATRP）, reversible addition-fragmentation chain transfer （RAFT） and conventional free radical polymerization （FRP） of polyethylene glycol methyl ether methacrylate （PEGMEMA） and polyethylene glycol dimethacrylates （PEGDMA） were conducted respectively, and their reaction kinetics and gelation behavior were investigated with respect to the polymerization rate, vinyl conversion, gel point, and evolution of network. All the three systems experienced autoacceleration of the reaction. The rate autoacceleration in the ATRP was caused by diffusion-controlled radical deactivation, while that in the RAFT was attributed to diffusion-controlled addition of propagating radicals to RAFT-capped chains. In the ATRP and RAFT systems, the slow growth of primary chains allowed adequate chain relaxation and diffusion of reacting species, which reduced the probability of intramolecular cyclizations and limited the formation of microgels, leading to earlier gelation, as compared with the FRP system. The crosslinking networks in the ATRP and RAFT developed mainly through gel radical propagation with monomers, along with incorporation of branched polymers, resulting in a gradual increase in gel fraction and network density.