PS-b-PNVIm(Bu)BF4离子液体嵌段聚合物的RAFT合成及表征

摘要

以S-十二烷基-S’-(α,α’-二甲基-α”-乙酸)-三硫代碳酸酯为链转移剂,制备了窄分布的聚苯乙烯大分子链转移剂,再用该大分子链转移剂制备聚苯乙烯-b-聚N-乙烯基咪唑(PS-b-PNVIm)两嵌段聚合物.通过与溴代正丁烷发生季铵化反应并与氟硼酸钠进行阴离子交换,得到聚苯乙烯-b-聚1-丁基-3-乙烯基咪唑氟硼化物[PS-b-PNVIm (Bu) BF4].运用1H NMR、IR和凝胶渗透色谱(GPC)等技术对产物的结构和分子量及分子量分布进行表征,结果表明,嵌段聚合物为PS160-b-PNVIm82,分子量分布为1.52,合成过程具有活性/可控聚合特征.PS-b-PNVIm具有两亲性,原子力显微镜观察到水溶性球形胶束,胶束以PNVIm链段为壳,PS链段为核.%Macro-RAFT agent,poly(styrene) were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using S-dodecyl-S'-(α,α'-dimethyl-α"-aceαic-cid)-trithiocarbonate as the chain transfer agent.Poly (styrene)-b-poly (N-vinylimidazole) (PS-b-PNVIm) diblock polymers were synthesized using N-vinylimidazole as monomer and poly (styrene) as macro-RAFT agent.Then,poly (styrene)-b-poly (1-butyl-3-vinylimidazolium sodiumm tetrafluoroborate) (PS-b-PNVIm (Bu) BF4) ionic liquid copolymers were synthesized by the quaternary ammonium reaction of PS-b-PNVIm with bromobutane and then anion-exchange reaction with sodium tetrafluoroborate.The molecular structure and molecular weight of the products were characterized by1 H NMR,IR and GPC.The results indicate that RAFT is a successful access to the copolymer PS160-b-PNVIm82 with narrow molecular weight distribution (PDI =1.52).The spherical micelles from the amphiphilic block polymer PS160-b-PNVIm82,characterized by AFM,has formed in water with a shell of PNVIm chain,and a core of PS.