中文摘要：

利用点击化学（click）反应和原子转移自由基聚合（ATRP）相结合的方法,合成了聚（丙烯酸丁酯-b-甲基丙烯酸甲酯）（PBA-b-PMMA）环状嵌段聚合物.使用傅里叶红外光谱、核磁共振谱和凝胶渗透色谱对合成产物结构进行表征.利用热重分析和差示扫描量热法分析比较了PBA-b-PMMA环状嵌段聚合物与线性嵌段聚合物的热动力学性能,结果表明两者具有相近的玻璃化转变,而环状嵌段聚合物则表现出较高的热分解温度.透射电子显微镜观察分析发现环状嵌段聚合物呈现的微相结构与线性嵌段聚合物完全不同,环状嵌段聚合物的相分离呈现连续-分散相结构,分散相（PBA）形态类似于蠕虫状,相畴尺寸在纳米尺度;退火后,相畴尺寸也明显增加。

英文摘要：

Cyclic poly（ n-butyl acrylate）-block-poly（ methyl methacrylate）（ cyclic-PBA-b-PMMA） can be synthesized successfully by the combination of ATRP and click reactions. The cyclic copolymers were obtained by the intramolecular cyclization reactions between the linear precussors at high dilution. The chemical structures,molecular weights and molecular weight distributions of the cyclic block copolymers obtained were well characterized by Fourier transform infrared spectroscopy,nuclear magnetic resonance spectroscopy and gel permeation chromatography. The thermal properties of these cyclic block copolymers and their linear counterparts were characterized by differential scanning alorimetry and thermogravimetric analysis. It is interesting that the cyclic block copolymers have similar glass transition temperatures but higher degradation temperatures compared to their linear counterparts. The morphologies of the prepared samples were investigated via transmission electron microscopy. Unlike the linear block polymers,the cyclic block copolymers exhibited unique morphologies. Obviously,the cyclic block copolymers displayed a continuous dispersed morphology,and the dispersed phase had a worm-like structure. Meanwhile,nano-scaled phase separation was also observed between PBA and PMMA phasees. By means of annealing above the glass transition temperatures of the two blocks,PBA and PMMA,both linear and cyclic copolymers possessed well ordered nano-structures,and the size of these separated domains increased after annealing.