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采用可逆加成断裂链转移自由基聚合方法,成功地制备了两亲嵌段共聚物聚甲基丙烯酸甲酯-b-聚丙烯酸-co-聚异丙基丙烯酰胺(PMMA-b-(PAA-co-PNIPAM)。利用傅立叶红外光谱、核磁共振和透射电镜研究了共聚物的结构特征;用GPC测定了其分子量和分子量分布。透射电镜、激光粒度分析仪和动态光散射结果表明嵌段共聚物在水溶液中能够自组装形成直径为200nm的胶束颗粒。通过紫外-可见分光光度计和差示扫描量热法测得了不同pH值下嵌段共聚物的低临界溶解温度(LCST)。经过接枝后的嵌段共聚物的LCST比PNIPAM要高,且随着pH值的降低,聚合物的LCST随之降低。聚合物的LCST可以通过AA链段与NIPAM链段的比例、温度、pH值来控制。
The amphiphilic block copolymer PMMA-b-polyacrylic acid-co-polyisopropylacrylamide (PMMA-b- (PAA- co-PNIPAM). The molecular weight and molecular weight distribution of the copolymer were investigated by Fourier transform infrared spectroscopy, nuclear magnetic resonance and transmission electron microscopy. The results of transmission electron microscopy, laser particle size analyzer and dynamic light scattering showed that the block copolymer The self-assembled micelles with diameter of 200nm can be formed in aqueous solution.The LCST of block copolymers at different pH values were measured by UV-visible spectrophotometer and differential scanning calorimetry The LCST of the block copolymer after the branch is higher than that of the PNIPAM, and the LCST of the polymer decreases with the decrease of the pH.The LCST of the polymer can be determined by the ratio of the AA segment to the NIPAM segment, the temperature, the pH value To control.