氮氧稳定自由基聚合与原子转移自由基聚合结合制备梳形支化聚苯乙烯的反应行为  

Reaction Behavior in Preparation of Comb-like Branched Polystyrene by Combination of Nitroxide-Mediated Radical Polymerization and Atom Transfer Radical Polymerization

作　　者：王美玉[1] 徐晓梅[1] 刘佳楠[1] 陆梦雅 朱梦冰[1] 俞强[1] 

机构地区：[1]常州大学材料科学与工程学院,江苏省太阳能电池材料与技术重点实验室,江苏常州213164

出　　处：《高校化学工程学报》2014年第1期98-103,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：江苏省太阳能电池材料与技术重点实验室资助项目

摘　　要：为了实现对梳形支化聚苯乙烯结构的精确控制，采用核磁共振（1H-NMR）、多角度激光散射联用凝胶渗透色谱（GPC-MALLS）和气相色谱（GC）表征聚合物结构和观察反应动力学，研究了苯乙烯（St）与对氯甲基苯乙烯（p-CMS）氮氧稳定自由基共聚合（NMP）制备 P（St-co-CMS）的反应行为以及以 P（St-co-CMS）为大分子引发剂引发苯乙烯原子转移自由基聚合（ATRP）制备梳形支化聚苯乙烯的反应行为。结果表明，在反应温度为130℃，苯甲醚为溶剂，BPO/HTEMPO为引发体系引发St与p-CMS的氮氧稳定自由基共聚合过程中，St和p-CMS的转化速率接近，p-CMS按其在单体混合物中的比例均匀进入共聚物分子链，共聚物分子量随转化率增加线性增大，P（St-co-CMS）的组成和分子量可控。在反应温度为100℃，苯甲醚为溶剂，CuCl/PMDETA为催化体系，P（St-co-CMS）为引发剂引发St的ATRP反应体系中，氯甲基全部用于引发St聚合，形成梳形支链；低转化率阶段，聚合物分子量随转化率增加呈线性增长，分子量分布较窄；在较高转化率下，聚合体系发生交联，形成凝胶；P（St-co-CMS）中p-CMS含量越高，凝胶越早发生。通过选择不同p-CMS含量的 P（St-co-CMS）为大分子引发剂以及将苯乙烯转化率控制在一定范围，制得了主链分子量在25000～30000、支链数目在6.3～42.6、支链分子量在6000～17000的一系列梳形支化PS。Reaction behaviors of nitroxide-mediated radical copolymerization （NMP） of styrene （St） and p-chloromethyl styrene （p-CMS） and following the atom transfer radical polymerization （ATRP） of styrene with P（St-co-CMS） as the macroinitiator to prepare the polystyrene were investigated for the purpose of precisely controlling the structure of the prepared comb-like branched polystyrene. Reaction kinetics and polymer structures were characterized by 1H-NMR, GPC-MALLS and GC. The experimental results show that St and p-CMS enter the copolymer chains with almost the same conversion rate during the NMP of St and p-CMS with BPO/HTEMPO as initiating system, anisole as the solvent at 130℃, which demonstrates that the p-CMS units are distributed uniformly along the P（St-co-CMS） chains. Well-defined P（St-co-CMS） with controlled composition and molecular weight were synthesized by controlling the monomer molar feed ratio and monomer conversion. In the ATRP of styrene with P（St-co-CMS） as the macroinitiator, CuCl/PMDETA as catalyst , anisole as the solvent at 100℃, all the p-CMS groups are consumed in initiating the ATRP of styrene to form the comb-like branched PS. In lower conversion region, the reaction proceedes in a controlled manner. However,after monomer conversion reaches a certain level, gelation occurres due to the bimolecular coupling reaction between PS macromolecular radicals. The higher the p-CMS fraction is in P（St-co-CMS）, the earlier the gelation occurres. By selecting P（St-co-CMS） macroinitiator with different p-CMS fractions, and controlling the monomer conversion within a certain levels, a series of comb-like branched polystyrenes with molecular weight of main chain between 25000～30000, the average branch number of each main chain between 6.3～42.6, and the molecular weight of branch chain between 6000～17000, were prepared.

关 键 词：梳形支化聚苯乙烯 氮氧稳定自由基聚合 原子转移自由基聚合 反应行为 

分 类 号：O631.5[理学—高分子化学] O632.13[理学—化学]