温度及pH敏感性羟乙基甲壳素水凝胶的合成及其性能研究

Study on Preparation and Properties of Temperature and pH-Sensitive Hydroxythyl Chitin Hydrogels

为得到应用性能好的医用材料 ,用氯乙醇对甲壳素进行醚化改性 ,得到水溶性甲壳素衍生物———羟乙基甲壳素(Hydroxyethylchitin ,HECH) ,用丙三醇三缩水甘油醚 (PTGE)对羟乙基甲壳素进行交联 ,得到了新型的水凝胶。考察了不同交联度的水凝胶的 pH和温度敏感性 ,发现该水凝胶是pH敏感性水凝胶 ,在 pH <6.98的缓冲溶液中 ,凝胶的溶胀度随着 pH的下降而迅速增大 ,在 pH =1.0 0的缓冲溶液中 ,凝胶的溶胀度达到了最大值 ;在去离子水中凝胶的溶胀度随着温度的升高而增大 ,是“热胀型凝胶”。

Hydroxyethyl chitin is a water soluble chitin derivative which was made by means of etherification of chitin. Ethylene chlorohydrin was used as an etherification reagent in this study . Hydroxyethyl chitin showed an excellent solubility in water. Three novel hydrogels based on Glycol chitin were obtained by using different amounts of PTGE as cross-linking reagents under 50℃ respectively. The swelling behaviour, swelling kinetics of hydroxyethyl chitin hydrogel and the effects of temperature, pH value on the swelling ratio of hydrogels were studied. The results showed that the swelling ratio in acid buffer solution was bigger than that in basic buffer solution, and it improved with the decrease of pH value. The swelling ratio of hydrogel increased with the increase of temperature from 25℃ to 50℃, and it increased sharply from 35℃ to 50℃. The hydroxyethyl chitin hydrogels show good sensibility to temperature and pH value.