温度及pH敏感N-异丙基丙烯酰胺/β-环糊精水凝胶的合成与性能研究

用顺丁烯二酸酐 (MAH)对具有分子包结能力的 β 环糊精 (β CD)进行化学改性 ,合成出了丁烯二酸单酯化 β CD单体 (MAH β CD) .通过氧化还原自由基引发MAH β CD与N 异丙基丙烯酰胺 (NIPA)聚合 ,合成出含 β CD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MAH β CD单体及共聚物的结构和组成进行了表征 .溶胀研究结果表明 ,该水凝胶具有较好的pH、温度及离子强度敏感性 ;并且水凝胶在较高羧基(—COOH)含量和弱碱环境中 ,仍能表现出明显的温敏性

SYNTHESIS AND PROPERTIES OF pH- AND TEMPERATURE-SENSITIVE HYDROGEL CONTAINING N-ISOPROPYLACRYLAMIDE AND β-CYCLODEXTRIN

A novel β cyclodextrin ( β CD) based monomer (MAH β CD) containing vinyl and carboxyl functional groups was synthesized by reaction of β CD with maleic anhydride (MAH) in N,N dimethylformamide (DMF) at 80°C.Through copolymerization of this functional monomer with N isopropylacrylamide (NIPA ) in aqueous solution,a novel hydrogel (poly(NIPA co MAH β CD) with pH ,temperature and ionic strength sensitivities as well as with molecular inclusion behavior,was obtained using radical polymerization method.Both MAH β CD monomer and the gels obtained were characterizited using 13 C NMR , IR spectra,and element analysis.The equilibrium swelling ratios (ESR) of the hydrogels have been investigated under conditions of different pH,temperature and ionic strength.The results indicated that the ESR presents remarkable response to changes of pH,temperature,or ionic strength.Interestingly,under higher content of —COOH groups and weak base,the hydrogel still possesses evidently temperature sensitivity behavior.