温度及pH敏感P(DMAEMA-g-PEG)水凝胶的合成与性能研究

Synthesis and properties of pH and temperature-sensitive P(DMAEMA-g-PEG) hydrogels

通过氧化还原自由基溶液聚合制备了聚甲基丙烯酸-N,N′-二甲氨基乙酯接枝聚乙二醇共聚水凝胶P(DMAEMA-g-PEG)。实验结果表明,该水凝胶具有温度、pH敏感性及溶胀-退胀可逆性,其相转变温度在45℃左右。少量PEG大分子单体的加入,使水凝胶具有较高的溶胀率,但随着PEG大分子单体用量的增大,溶胀率反而下降;水凝胶在酸性介质中溶胀,碱性介质中收缩;扫描电子显微镜观察发现,在干燥状态下该凝胶具有多孔结构。

A novel temperature and pH-sensitive graft copolymer hydrogel was synthesized by redox initiator free radical solution polymerization of 2-（N,N′-dimethylamino）ethyl methacrylate（DMAEMA） and polyethylene glycol（PEG） macromonomer.The obtained results show that the hydrogels have temperature and pH double sensitivities as well as swelling-shrinking reversibility.The phase transition temperature of these hydrogels is about 45℃.The addition of a small quantity of PEG macromonomer makes the hydrogel have high swelling ratio.But with the increasing amount of PEG macromonomer,the swelling ratio decreases.The hydrogels swell in acidic medium and shrink in alkaline medium.It was found that the hydrogels have porous structure by scanning electron microscopy.