一种原位生成的原子转移自由基聚合的新型引发剂

通过元素溴与偶氮二异丁腈（AIBN）在二甲基甲酰胺（DMF）中反应合成了一种新型的原子转移自由基聚合（ATRP）引发剂α-溴代异丁腈（B IBN）,B IBN的DMF溶液（B IBN-DMF）可直接作为引发剂引发甲基丙烯酸甲酯和苯乙烯的原子转移自由基聚合.考察了B IBN-DMF分别与不同的催化体系CuB r/PMDETA,FeC l2.4H2O/MA5-DETA及FeC l2.4H2O/PPh3等相匹配时聚合的情况.动力学研究表明：以ln（[M]0/[M]）对反应时间作图,图线呈直线,证明聚合反应过程符合一级反应动力学.聚合产物分子量分布窄（Mw/Mn=1.1-1.3）.实验结果证实反应具有良好的可控性,不经分离可直接使用B IBN的DMF溶液,B IBN-DMF作为引发剂引发ATRP是一种高效而便捷的方法.

A novel initiator for atom transfer radical polymerization

A novel initiator α-bromoisobutylnitrile （BIBN） was synthesized by the reaction between bromine and 2,2＇-azobisisobutyronitrile （AIBN） in dimethyl formamide （DMF）, and used directly in original state （BIBN-DMF） as initiator for atom transfer radical polymerization （ATRP） of MMA and St in conjunction with CuBr/PMDETA （ N, N, N′, N＂, N＂ -pentamethyl diethylenetriamine ）, FeCl2 · 4H2O/MA5-DETA （ N, N, N′, N＂, N＂-pentamethylacylate diethylenetriamine） or FeCl2 4H2O/PPh3 as catalyst/ligand respectively. The linearity of ln（ [M]0/[ M] ） vs time indicated the polymerizations were first-order and the concentration of growing radicals remained constant throughout polymerization, producing polymers were with low polydispersities （ 1. 1 - 1.3 ）. The results showed that the polymerizations were well-controlled, and BIBN-DMF was a good initiator with high initiator efficiency （81% -98% ）, the direct use of BIBN-DMF without separation as initiator of ATRP has proved to be a simple, convenient and effective method.