不同双硫酯用量下RAFT自由基交联聚合体系的反应动力学及交联结构  

Kinetics of RAFT Radical Crosslinking Polymerization and Crosslinking Structure With Different Dithioester Concentrations

作　　者：朱梦冰[1] 甘泉[1] 刘晶如[1] 徐之光[1] 张洪文[1] 俞强[1] 

机构地区：[1]常州大学材料科学与工程学院常州市高分子新材料重点实验室,江苏常州213164

出　　处：《高分子材料科学与工程》2011年第5期78-81,共4页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(20674032)

摘　　要：考察了二硫代苯甲酸苄酯(BDB)用量对二甲基丙烯酸聚乙二醇酯/甲基丙烯酸聚乙二醇甲基醚酯可逆加成-断裂链转移(RAFT)自由基交联聚合动力学、凝胶行为和交联结构的影响。随BDB用量增加,增长自由基浓度降低,导致聚合速率不断下降。链自由基与休眠链的加成反应进入扩散控制后使得RAFT交联聚合出现自加速,随BDB用量增加自加速推迟。当双键/BDB的物质的量比小于100/1时,凝胶点随BDB用量增加而降低;在高BDB用量下,凝胶点随BDB用量增加而增大。交联密度随BDB用量增加有所增大,交联网络结构更加均匀。Reaction kinetics,gelation behavior and crosslinking structures of reversible addition-fragmentation chain transfer（RAFT） radical polymerization of poly（ethylene glycol） dimethacrylates（PEGDMA） and poly（ethylene glycol） methyl ether methacrylate（PEGMEMA） with different molar ratios of benzyl dithiobenzoate（BDB） as RAFT agent were investigated.With the increase of BDB molar ratio,concentration of the growing radicals was reduced in the reaction systems,resulting in the decrease of polymerization rate.Due to diffusion-controlled addition of growing radicals to the dormant species,significant autoacceleration occurred in the RAFT polymerization processes.The vinyl conversions at the onset of autoacceleration increased with BDB molar ratio.Gel point reduced as the BDB concentration increased when BDB molar ratio was between 0～1.0,and it increased as more BDB was introduced.The high molar ratio of BDB also gave rise to a high crosslinking density of the final RAFT products,and more homogeneous networks.

关 键 词：可逆加成-断裂链转移自由基聚合 双硫酯 动力学 凝胶行为 交联结构 

分 类 号：TQ316.65[化学工程—高聚物工业]