中文摘要：

以末端含有炔基的2-十二烷基三硫代碳酸酯-2-甲基-丙酸丙炔醇酯（DMPE）为链转移剂（CTA）,2,2′偶氮二异丁腈（AIBN）为引发剂,在N,N-二甲基甲酰胺（DMF）中,利用可逆加成-断裂链转移（RAFT）聚合反应制备了分子链末端带炔基的均聚物聚（N-丙烯酰基-L-缬氨酰甲胺）（PAVMA—C帒CH）,然后与叠氮基封端的聚乙二醇单甲醚（MPEG-N3）进行＂click＂偶合反应,制备具有温敏特性的光学活性嵌段聚合物MPEG-b-PAVMA.利用1H-NMR和体积排阻色谱（SEC）等表征了所合成的均聚物和共聚物的结构和分子量分布.1H-NMR结果表明所合成的嵌段共聚物中MPEG和PAVMA链段的重复单元数分别为115和55.利用紫外分光光度计测试了均聚物及嵌段聚合物的温敏特性,结果表明均聚物和共聚物在水中的低临界溶解温度（LCST）分别为6.5℃和19.5℃.比旋光度测试结果表明,均聚物和共聚物具有旋光性,同时相比于单体,其旋光能力有所降低.圆二色谱法（CD）的测试结果显示,均聚物和嵌段共聚物在220nm和197nm附近分别有一个较弱的正Cotton效应峰和一个较强的负Cotton效应峰,并且在水溶液中主要以无规的二级构象结构存在。

英文摘要：

Thermoresponsive and optically active polymer poly（N-acryloyl-L-valine N＇-methylamide）（PAVMA-C≡CH） bearing amino acidamide moieties in the side chain was synthesized via reversible additionfragmentation chain transfer（RAFT） polymerization using 2-dodecylsulfanylthiocarbonylsulfanyl-2-methylpropionic acid propargyl alcohol ester（DMPE） with alkyne group in the end as the chain transfer agent（CTA）.Diblock copolymer MPEG-b-PAVMA was then prepared from ＂click＂coupling reaction between PAVMA-C≡CH and polyethylene glycol monomethylether capped by azide group（MPEG115-N3） in conjunction with CuSO4 /ascorbate sodium as catalytic system.The chemical structures and molecular characters were evaluated by 1H-NMR and size exclusion chromatography（SEC）,respectively.The number of repeating unit for MPEG and PAVMA was 115 and 55,respectively,which was calculated from 1H-NMR analysis.The lower critical solution temperatures（LCSTs） for PAVMA and MPEG-b-PAVMA in water were 6.5℃ and 19.5℃,respectively,which were measured by transmittance tests on a UV-Vis spectrophotometer equipped with a temperature controller system.Specific optical rotation results showed that optical activity of the prepared PAVMA-C≡CH homopolymer and corresponding MPEG-b-PAVMA copolymer decreased comparing with that of monomer（AVMA） due to the variation of micro-conformation during polymerization.Circular dichroism（CD） spectra for the aqueous solution of resulted polymers at 5℃ exhibit a weak Cotton effect peak at about 220 nm and a strong negative Cotton effect peak at around 197 nm,indicating random coil conformation for polymer chains in solution.