湿热处理对壳聚糖/明胶共混膜结构与抗水性能的影响

Influence of Moist Heat Treatment on the Water Resistance Properties and Structure of Chitosan/Gelatin Blend Films

用流延法成功制备了3种不同配比的壳聚糖/明胶共混膜, 并对共混膜进行湿热处理,使共混膜的抗水性能得到了不同程度的提高. 在60 ℃、相对湿度75%条件下对共混膜(CSG20)湿热处理24 h,与未处理的膜相比, 共混膜在蒸馏水中的吸水率下降了81%, 在pH 2.8的酸性媒介中的失重率减少了37%. 红外(IR)光谱和X 射线衍射(XRD)分析表明,共混膜在抗水性能方面的变化是明胶和壳聚糖在热引导下发生交联和结晶结构发生变化引起的.

Chitosan/gelatin blend films were prepared successfully by solution method. The films were then exposed to moist heat at different conditions for several time intervals. The influence of moist heat treatment on structure of blend films was investigated by FT-IR and X-ray diffraction. After treatment, the percentage of water sorption in distilled water and dissolution of blend films in acid (pH 2.8) were gradually decreased. After the blend films were exposed to moist heat at 60 ℃ and 75% relative humidity for 24 hours, the percentage of water sorption in distilled water and weight loss in acid of blend films were decreased 81% and 37%, respectively, compared with the freshly prepared films. The results from FT-IR and X-ray diffraction show that change in the water resistance of blend films is usually caused by heat-induced change of crystallinity in blend films and the formation of crosslinks between the polymer molecules.