采用流延成型法制备了明胶(gel)/聚乙烯醇(PVA)共混膜,用甲醛作为交联剂进行溶液交联制备了交联改性的gel/PVA复合膜,考察了交联剂用量对gel/PVA共混膜力学性能及溶解性能的影响,并采用红外光谱(FT-IR)、X射线衍射(XRD)、差示扫描量热(DSC)、热重(TG)等对复合膜交联前后的结构及性能进行了表征。测试结果表明,随着甲醛用量的增加,复合膜的拉伸强度呈现逐渐增加的趋势,而断裂伸长率基本上呈现逐渐降低的趋势;FT-IR 光谱结果表明,甲醛不仅与明胶中-NH2反应,也与 PVA 发生了缩醛化反应;DSC、TG结果显示,交联后复合膜的热稳定性明显增加。
The gelatin/PVA biodegradable blend films were prepared based on gelatin and poly(vinyl alcohol)by a simple solvent casting method and modified by crossing-linking using formaldehyde.In this paper,the effects of content of crosslinking agent on mechanical properties and soluble ratio of the gelatin/PVA blend films were studied.The chemical structure of the blend films were investigated by Fourier transform infrared spectroscopy (FT-IR),X-ray diffraction (XRD),differential scanning calorimetr (DSC)and thermogravimetry analysis (TG)and so on.The results showed that the tensile strength of the blend films were gradually increased and elongation at break of the blend films were gradually decreased with increasing the content of formaldehyde. The FT-IR result showed that formaldehyde reacted with not only -NH2 of gelatin but also PVA.The results of DSC and TG displayed that thermal stability of the blend films was improved after crosslinking modification using formaldehyde.