Atom transfer radical polymerization of styrene initiated by α,α dibromotoluene and catalyzed by copper (I) bromide/2,2′ bipyridine was carried out.The produced polymers had narrow molecular weight distributions an...Atom transfer radical polymerization of styrene initiated by α,α dibromotoluene and catalyzed by copper (I) bromide/2,2′ bipyridine was carried out.The produced polymers had narrow molecular weight distributions and controlled molecular weights that were proportional to monomer conversion.In order to show that α,α dibromotoluene is a bifunctional initiator for atom transfer radical polymerization of styrene,polymerization of styrene using a mixture of 1 phenyl ethyl bromide and α,α dibromotoluene initiators was also carried out.The GPC trace of obtained polystyrene exhibited bimodal distribution.The peak appearing at lower elution time corresponds to polymer from α,α dibromotoluene and the other one corresponds to polymer from 1 phenyl ethyl bromide.The ratio of peak molecular weight of the polymer from α,α dibromotoluene to that from 1 phenyl ethyl bromide was found to be close to two,confirming that the polymer from α,α dibromotoluene grows from both ends of the polymer chain.Furthermore,the ratio of the two peak surface area changed with the molar ratio of α,α dibromotoluene to 1 phenyl ethyl bromide.展开更多
以1,4-二氧六环为溶剂,AIBN为引发剂,N-[(4-溴-3,5-二氟)苯基]马来酰亚胺(BDPM)和苯乙烯(St)为原料,通过溶液聚合合成了N-[(4-溴-3,5-二氟)苯基]马来酰亚胺/苯乙烯(BDPM/St)二元共聚物,考察了单体投料比、单体总浓度、引发剂浓度和反应...以1,4-二氧六环为溶剂,AIBN为引发剂,N-[(4-溴-3,5-二氟)苯基]马来酰亚胺(BDPM)和苯乙烯(St)为原料,通过溶液聚合合成了N-[(4-溴-3,5-二氟)苯基]马来酰亚胺/苯乙烯(BDPM/St)二元共聚物,考察了单体投料比、单体总浓度、引发剂浓度和反应时间对共聚的影响。采用红外光谱(FT-IR)和1 H NMR对其结构进行了表征,根据元素分析测定结果,计算得到共聚物中两种单体单元的摩尔配比接近1∶1,表明了BD-PM和St具有明显的交替共聚趋势。通过热重分析对BDPM/St的热性能进行了表征,结果表明,二元共聚物具有优良的热稳定性。GPC测定其相对分子质量(Mn=2.17×105,MW=2.85×105,D=1.4),表明BD-PM/St聚合度较高。展开更多
文摘Atom transfer radical polymerization of styrene initiated by α,α dibromotoluene and catalyzed by copper (I) bromide/2,2′ bipyridine was carried out.The produced polymers had narrow molecular weight distributions and controlled molecular weights that were proportional to monomer conversion.In order to show that α,α dibromotoluene is a bifunctional initiator for atom transfer radical polymerization of styrene,polymerization of styrene using a mixture of 1 phenyl ethyl bromide and α,α dibromotoluene initiators was also carried out.The GPC trace of obtained polystyrene exhibited bimodal distribution.The peak appearing at lower elution time corresponds to polymer from α,α dibromotoluene and the other one corresponds to polymer from 1 phenyl ethyl bromide.The ratio of peak molecular weight of the polymer from α,α dibromotoluene to that from 1 phenyl ethyl bromide was found to be close to two,confirming that the polymer from α,α dibromotoluene grows from both ends of the polymer chain.Furthermore,the ratio of the two peak surface area changed with the molar ratio of α,α dibromotoluene to 1 phenyl ethyl bromide.
文摘以1,4-二氧六环为溶剂,AIBN为引发剂,N-[(4-溴-3,5-二氟)苯基]马来酰亚胺(BDPM)和苯乙烯(St)为原料,通过溶液聚合合成了N-[(4-溴-3,5-二氟)苯基]马来酰亚胺/苯乙烯(BDPM/St)二元共聚物,考察了单体投料比、单体总浓度、引发剂浓度和反应时间对共聚的影响。采用红外光谱(FT-IR)和1 H NMR对其结构进行了表征,根据元素分析测定结果,计算得到共聚物中两种单体单元的摩尔配比接近1∶1,表明了BD-PM和St具有明显的交替共聚趋势。通过热重分析对BDPM/St的热性能进行了表征,结果表明,二元共聚物具有优良的热稳定性。GPC测定其相对分子质量(Mn=2.17×105,MW=2.85×105,D=1.4),表明BD-PM/St聚合度较高。
