2-溴代环己酮引发的苯乙烯原子转移自由基聚合

在铜体系催化的卤原子转移自由基聚合反应中 ,已有多种卤化物被作为引发剂使用 ,如α-卤代酯、α-卤代腈、多卤代烃、卤代苄基化合物及芳磺酰氯等 [1] ,最近又有报道称 N-氯代磺酰胺也可以作为引发剂使用 [2 ] .但以 α-卤代酮作引发剂只在钌系 [3～ 7]、铁系 [8]及镍系 [9]催化的原子转移自由基聚合中进行了研究 ,尤其是 Swawamoto等 [3～ 6] 对 Ru Cl2 (PPh3 ) 3 作催化剂 ,α,α-二氯苯甲酮和 1 ,1 ,1 -三氯丙酮作引发剂进行的甲基丙烯酸甲酯的原子转移自由基聚合进行了非常系统的研究 .由于羰基的吸电子能力较强 ,α-卤代酮的卤原子…

Atom Transfer Radical Polymerization of Styrene Initiated by 2-Bromocyclohexanone

The atom transfer radical polymerization of styrene was carried out with an α-haloketone, 2-bromocyclohexanone, as the initiator in the presence of CuBr/Cu/2,2′-bipyridine or CuBr/ N,N,N′,N″,N″-pentamethyldiethylenetriamine catalytic system.The polymerization proceeded in a living fashion with that the number average molecular weight increased linearly with the increase of monomer conversion and the polydispersity was relatively low through the polymerization process, especially with CuBr/N,N,N′,N″,N″-pentamethyldiethylenetriamine as the catalyst.The initiation efficiency of 2-bromocyclohexanone in both catalysis systems was about 80%. 1HNMR and 13CNMR verified the presence of 2-oxocyclohexyl and bromine atom at the botHEnds of polystyrene chains respectively, which were derived from the 2-bromocyclohexanone.