中文摘要：

以AIBN为引发剂，AET．HCl为链转移剂，通过自由基聚合制备了具有温敏性的P（NIPAM—CO-NMAM）-g-（PLLA—g-MAAH）接枝共聚物．通过NMR、FTIR和GPC分析研究了生成的接枝共聚物的化学结构、相对分子质量及相对分子质量分布；利用DLS和TEM手段对产物的粒子尺寸、分布及其形貌进行了研究；利用透光率及表面张力测定研究了其温敏行为及胶束化行为．实验结果表明，合成的P（NIPAM-CO-NMAM）-g-（PLLA—g-MAAH）接枝共聚物在水溶液中形成近似球形胶束，平均粒子尺寸约20nm，具有最低临界溶液温度约42℃，临界胶束浓度约28mg／L．MTT试验表明合成的共聚物无细胞毒性或有轻微毒性，有望成为一种有潜力的生物医用材料．

英文摘要：

Thermosensitive P（NIPAM-co-NMAM）-g-（PLLA-g-MAAH） graft copolymers were synthesized via a free radical polymerization route using 2, 2＇-azobisisobutyronitrile （AIBN） as an initiator and 2- aminoethanethiol hydrochloride （AET. HCl） as a chain transfer agent. The structure, molecular weight and polydispersity of the copolymer were characterized by NMR, FTIR and GPC. The morphologies, size and size distribution of the as-synthesized copolymer micelles were investigated by TEM and DLS. The ther- mosensitive behavior and micellization were examined with UV-vis and surface tension measurements. The experimental results showed that the as-synthesized P（NIPAM-co-NMAM）-g-（PLLA-g-MAAH） copolymers formed sphere-like micelles in aqueous solution, with an average size of approximate 20 nm, a low critical solution temperature of about 42 ℃, and a critical micelle concentration of ca. 28 mg/L. MTT assay indicated that the copolymers had no cytotoxicity or slight toxicity, and could be used as a potential biomedical material.