基于光聚合星型PEG-b-PCL大分子单体可生物降解水凝胶的合成及表征

以辛酸亚锡为催化剂 ,通过星型聚乙二醇 (PEG)引发ε 己内酯 (CL)开环聚合 ,制备了PEG b PCL嵌段共聚物 ,进一步以丙烯酸酯封端 ,合成了 3种水溶性大分子单体 .以 2 ,2 二甲氧基 2 苯基苯乙酮为引发剂 ,在紫外光作用下 ,大分子单体在水中由于胶束的形成能够迅速聚合形成水凝胶 .利用1 H NMR、FTIR、DSC、TGA、ESEM、凝胶含量、溶胀比等分析测试手段对大分子单体及其形成的水凝胶进行了表征 .结果表明 ,干胶迅速吸水而达到溶胀平衡 ,水凝胶具有较大的溶胀比和高的水含量 ;随着PEG臂数的增加 ,干胶的熔融峰顶温度下降 ,凝胶的溶胀比减小 ;ESEM图片上清晰地表明水凝胶的网络结构

SYNTHESIS AND CHARACTERIZATION OF BIODEGRADABLE HYDROGELS BASED ON PHOTOPOLYMERIZED STAR-SHAPED POLY(ETHYLENE GLYCOL)- co-POLY(ε-CAPROLACTONE) MACROMERS

The star shaped block copolymers were prepared by ring opening polymerization of ε caprolactone in the presence of multiarm PEG using stannous octoate as a catalyst.Based on these star shaped PEG b PCL,soluble macromers terminated with acrylate groups were synthesized.The amphiphilic nature of the macromers causes them to assume a micellar conformation in water,which enables them to undergo rapid polymerization using photoinitiator under UV radiation.Macromers and their hydrogels were characterized by 1H NMR、FTIR、DSC、TGA、ESEM、 gel content and swelling ratio etc. It is shown that dried gels absorb water rapidly,and hydrogels have high swelling ratio and water content.With the increase of arm numbers of PEG,the temperature of the melting peak of dried gels and the swelling ratio of hydrogels decrease;The photograph of ESEM indicated clearly the network structure of the hydrogel.