物理交联型生物医用聚氨酯水凝胶的合成研究

我们采用碳酸亚乙酯(E thy lene carbonate)与乙醇胺(E thano lam ine)反应合成得到含有氨基甲酸酯结构的新型小分子二醇扩链剂双羟乙基氨基甲酸酯(B is-hydroxy lethy l carbom ate(EC-AE))。用一步法通过扩链剂EC-AE和1,4-bu taned io l合成了聚氨酯聚合物PUA 25和PU B 25,对其结构用红外光谱分析(FT-IR)、差动扫描量热法分析(DSC)进行了表征,其结果表明:PUA 25微相分离程度比PU B 25的低,即PUA 25的硬段之间形成氢键的数量较PU B 25的少,相混和程度大。并以PUA 25和PU B 25为原料,对其形成的物理交联水凝胶进行了研究,发现PUA 25能够制备物理交联型水凝胶,且该水凝胶随着冷却-加热-冷却过程的重复而出现“凝胶-溶液-凝胶”的循环转变,证明了相容性程度较高的聚氨酯易形成水凝胶。

Study on Synthesis of Physically Crosslinked Biomedical Polyurethane Hydrogel

In this study,using ethylene carbonate and ethanolamine,we synthesized a novel diol chain-extender,bis-hydroxylethyl carbomate(EC-AE),which contains carbomate structure.The polyurethanes, PUA25 and PUB25,with different extenders,EC-AE and BDO,were synthesized by one-step polymerization,respectively.Their structures were characterized by using FT-IR and DSC.The results indicated that the microphase separation degree of PUA25 was less than that of PUB25,in other words,the amount of hydrogen bonding between hard segments and soft segments in PUA25 was superior to that in PUB25.And the formation of physically crosslinked hydrogels prepared by PUA25 and PUB25 were studied in detail.It was found that only PUA25 can form hydrogel in situ from solution state by cooling.And this kind of hydrogels showed the transition cycle of "gel-sol-gel" under "cooling-heating-cooling" thermal cycles,respectively.The results suggested that the physically crosslinked polyurethane hydrogels were easily possessed in high degree of phase mixing.