磺基甜菜碱型两性离子聚合物的合成

Synthesis of zwitterionic copolymer containing sulfobetaine groups

以甲基丙烯酰氧乙基二甲基胺(DM)和1,3-丙基磺内酯为原料,在55℃下反应20 h,合成了3-(2-甲基丙烯酰氧乙基二甲胺基)丙磺酸盐(DMAPS);并在盐溶液中与丙烯酰胺(AM)单体进行自由基共聚合反应,获得了净电荷为零的磺基甜菜碱型两性离子共聚物P(AM-DMAPS);采用红外光谱对共聚物进行表征;考察了总单体的质量分数、单体摩尔分数、引发剂用量、反应时间、反应温度、c(NaCl)以及氧化剂与还原剂的物质的量比等因素对聚合反应的影响;获得最佳反应条件:总单体的质量分数25%,x(DMAPS)=5%,w(引发剂)=0.03%,反应时间10 h,反应温度25℃,c(盐)=0.5 mol/L,n(氧化剂)∶n(还原剂)=1.4∶1。在此条件下获得的共聚物特性粘数为18.5 mL/g。

A zwitterionic monomer of N,N-dimethyl-N-methacryloyloxyethyl-N-（3-sulfopropyl）ammonium（DMAPS）was prepared by the ring opening reaction of 1,3-cyclopropanesultone with dimethylaminoethyl methacrylate（DM） at 55 ℃ for 20 h.Zwitterionic copolymers（P（AM-DMAPS））containing sulfobetaine groups were synthesized by copolymerization of acrylamide（AM）and DM in aqueous solutions.The structure of the copolymers were characterized by FTIR spectroscopy.The effects of total monomer concentration,DM mole fraction in total monomer,the amount of initiator,reaction time,reaction temperature,the concentration of salt solution and mole ratio of oxidant and reductant on polymerization were investigated.The optimal reaction conditions are：the total monomer concentration is 25%,DM mole fraction in total monomer is 5%,the amount of initiator is 0.03%,reaction time is 10 h,reaction temperature is 25 ℃,the concentration of salt solution is 0.5 mol/L,mole ratio of oxidant and reductant is 1.4∶1.Under these conditions,the intrinsic viscosity of copolymer is 14.7.