甲基丙烯酸N,N-二甲氨基乙酯与丙烯酰β-环糊精共聚水凝胶的合成及其性能研究

用不同的方法合成了两种结构不同的丙烯酰 β 环糊精酯 (β CD 3 A和 β CD 6 A) ,以此为单体与甲基丙烯酸N ,N 二甲氨基乙酯 (DMAEMA)通过氧化还原自由基引发聚合 ,合成出两类含 β 环糊精结构单元的新型水凝胶 .用核磁共振 ,红外光谱及元素分析对两种单体及共聚物的结构和组成进行了表征 .溶胀实验结果表明 ,两类水凝胶均具有较好的pH、温度及离子强度敏感性 ,且因其交联网络结构不同 ,其溶胀性能有所差异

SYNTHESIS AND CHARACTERIZATION OF NOVEL HYDROGELS OF POLY( DMAEMA-co-β-CYCLODEXTRIN ACRYLATE)

Two kinds of β-cyclodextrin(β-CD)-acrylic monomers,β-CD-3-A and β-CD-6-A,carrying the acryl groups were synthesized relying on their reactivity of different hydroxyl groups in cyclodextrin. 13C-NMR spectra indicated that,for β-CD-3-A,acylation occurs at C-2 and C-3 positions of β-CD,and for β-CD-6-A,the acylation occurs at its C-2 and C-6 positions. Two functional hydrogels were synthesized by copolymerization of β-CD-3-A and β-CD-6-A with N,N-dimethylaminoethyl methacrylate(DMAEMA) using a redox initiator system in aqueous solutions. The hydrogels were characterized by FTIR and elementary analysis. The equilibrium swelling experiments show that the hydrogels possess pH-,ionic strength and thermo-sensitivities. However,due to the difference of monomer structures,the physical properties of the two hydrogels,especially their swelling behavior in response to the external stimuli,exhibit certain difference. It is reasonable to assume that the structure of β-CD-3-A in its hydrogel is more favorable to initiate hydrophobic interactions between dimethylaminoethyl segments and hydrophobic caves in β-CD,as a result,reducing the hydrogel's transition points. It can also be observed that the transition regions for both hydrogels shift to lower temperatures with the increase in contents of β-CD-3-A or β-CD-6-A.