【摘要】 利用L-丙氨酸和三聚光气反应制备了N-羧基-丙氨酸-环内酸酐(NCA)。以聚乙二醇单甲醚(M PEG)为原料,制备了端氨基聚乙二醇单甲醚(M PEG-NH2),并以此作为大分子引发剂,引发NCA开环聚合,合成了不同含量的聚L-丙氨酸-聚乙二醇嵌段共聚物(PLAM)。利用IR、NM R、DSC等方法对共聚物结构进行了表征,同时利用圆二色光谱(CD)考察了聚合物材料在水溶液中的二级结构。结果表明,M PEG-NH2引发NCA开环聚合得到的是嵌段共聚物,CD测试结果表明共聚物在水溶液中主链以α-螺旋构象存在,聚L-丙氨酸分子中引入亲水性聚乙二醇单甲醚能够改善材料的亲水性能。更多还原

【Abstract】 N-Carboxy-alanine acid anhydride（NCA） was synthesized by L-alanine and Triphosgen.MPEG was used to prepare amine-terminated poly（ethylene glycol） monomethyl ether（MPEG-NH₂）,which was used to initiate NCA ring opening polymerization to produce poly（L-Alanine）/poly（ethylene glycol） monomethyl ether（PLAM） diblock copolymers.The structural characteristics of copolymers were attested by IR,（）¹H-NMR,DSC,GPC,CD etc.The results show that products of NCA ring opening polymerization initiated by MPEGNH₂ are block copolymers.Copolymer′s block contents and number-average molecular weights were calculated from（）¹H-NMR.The results of CD show the copolymers in aqueous solution exist as α-helical conformation.The hydrophilicity of homopolymer was improved by adding hydrophilic MPEG.更多还原