摘要
用酶促开环聚合与ATRP方法相结合,制备了聚甲基丙烯酸六氟丁酯-聚己内酯-聚乙二醇-聚己内酯-聚甲基丙烯酸六氟丁酯(PHFMA-b-PCL-b-PEG-b-PCL-b-PHFMA)五嵌段聚合物.首先用Novozym e 435作为催化剂合成了聚己内酯-聚乙二醇-聚己内酯三嵌段聚合物,然后通过端基官能化法合成了大分子引发剂,并用其引发甲基丙烯酸六氟丁酯(HFMA)的ATRP反应,合成了五嵌段聚合物.通过核磁和GPC证明了大分子引发剂和五嵌段共聚物的结构,五嵌段共聚物的GPC分析表明这种合成方法的可行.共聚物胶束的直径和大小通过动态光散射方法和原子力显微镜测试,五嵌段共聚物在水中的的自组装行为也被研究.结果证明胶束是球形,其平均直径为77 nm.聚合物在四氢呋喃中的浓度对聚合物的聚集形貌有很大的影响.
A triblock copolymer PCL-b-PEG-b-PCL was prepared by enzymecatalyzed ring-opening polymerization of ε-caprolactone in the presence of catalyst Novozyme 435 and initiator PEG.The αbromoester terminated Br-b-PCL-b-PEG-b-PCL-b-Br macroinitiator was obtained in the subsequent esterification of end hydroxyl groups with α-bromopropionyl bromide and was used in the ATRP of 2,2,3,4,4,4-hexafluorobutyl methacrylate（HFMA）.A pentablock copolymer consisting of poly（ethylene glycol）（PEG）,polycaprolacrone（PCL） and poly（2,2,3,4,4,4-hexafluorobutyl methacrylate）（PHFMA） was synthesized.The structures of the polymers were characterized by NMR and GPC.Because of the industrial and scientific significance,increasing interest has been arising on the aggregates of complicated block copolymers in selective solvents.The self-assembly of the pentablock copolymer was investigated in aqueous solutions.The size and shape of the resulting micelles were investigated using dynamic light scattering and tapping-mode atomic force microscopy.The results demonstrated that the copolymeric micelles had a spherical shape with a mean diameter of about 77 nm.In addition,the micellar morphologies were influenced remarkably by changing the initial copolymer concentration in organic solvents.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2010年第2期199-204,共6页
Acta Polymerica Sinica
关键词
酶促开环聚合
原子转移自由基聚合
五嵌段聚合物
Enzymatic ring-opening polymerization Atom transfer radical polymerization Pentablock copolymer
