以环糊精为核的星形高分子合成及其温度、pH敏感性研究

以不同用量的氯乙酰氯与 β 环糊精反应 ,得到含有不同酰化度的氯乙酰化 β 环糊精 ,以此化合物为引发剂 ,采用原子转移自由基 (ATRP)引发甲基丙烯酸N ,N 二甲氨基乙酯 (DMAEMA)聚合 ,得到温度及pH敏感的以 β 环糊精为核的星形聚合物 .通过红外光谱、1 3C NMR、1 H NMR和氯元素滴定分析确定了酰化后的 β 环糊精的结构 ,并采用红外光谱、1 H NMR、元素分析、DSC表征了以 β 环糊精分子为核的星形聚甲基丙烯酸N ,N 二甲氨基乙酯的大分子结构 ,紫外光谱研究表明聚合物水溶液具有明显的温度和pH敏感性 .

SYNTHESIS AND CHARACTERIZATION OF THE THERMO- AND pH SENSITIVE STAR POLYMERS WITH A RIGID CORE OF β-CYCLODEXTRIN

Two kinds of chemical modified β-cyclodextrin(β-CD) with different acylation degree were synthesized relying on the content of chloroacetyl chloride agent used. The structures of β-CD with different degree of acylation were characterized using infrared spectroscopy, ()~(13)C-NMR, ()~~1H-NMR and titration analysis.Infrared spectroscopy and ()~(13)C-NMR indicated that acylations occurred at C-2 and C-6 position in β-CD,()~1H-NMR and titration analysis suggested that the acylation degrees of β-CD are 3.2 and 4.5,respectively.A series of star polymers having different average length of poly(N,N-dimethylaminoethyl methacrylate) were synthesized by atom transfer radical polymerization (ATRP) using anterior acylated β-CD as the initiator.The branch chain structure and their compositions were characterized using infrared spectroscopy,()~1H-NMR,element analysis and DSC.The star polymers prepared here had a hard β-CD core with the potential to form inclusion complexes with certain small organic compounds,and also their aqueous solutions were studied by UV spectroscopy in order to explore their thermo- and pH sensitivities.The results showed that the novel star polymers exhibited clearly thermo- and pH respondings in accordance with the change of the environment.