聚氨酯丙烯酸酯浸渍固化对淀粉-纤维素复合膜性能的影响

利用聚氨酯丙烯酸酯树脂（PUA）对淀粉-纤维素膜进行改性，以改善材料性能。先以玉米淀粉和纤维素为主要原料，在无机盐氯化锌水溶液中溶解，用流延法制备淀粉-纤维素混合膜（RSC）；再以PUA为浸渍树脂，采用浸渍固化法制备淀粉-纤维素-聚氨酯丙烯酸酯复合膜（RSC-PUA），考察树脂浓度、光固化时间等因素对复合膜力学性能、吸水性能的影响，并通过扫描电镜、X射线衍射仪、热重分析等手段表征复合膜形貌和结构。实验结果表明：最适宜树脂质量分数为30%，光固化时间为120s；RSC-PUA复合膜比RSC膜拉伸强度提高2.4倍，断裂伸长率提高6倍，吸水率降低了53.6%，热裂解温度增高113℃。以上结果表明，经PUA树脂改性后的复合膜的力学性能、耐湿性、热稳定性提高。

Effect of impregnation-solidification of polyurethane acrylate on the properties of starch-cellulose composite films

The polyurethane acrylate(PUA) was used to reinforce the starch/cellulose film(RSC),and to improve the properties of composite film. Specifically,the RSC film was prepared firstly by solution-casting method,which dissolved corn starch and cellulose in zinc chloride aqueous solution and casted the film by alcohol/water solution. After that,the RSC film was soaked in PUA/acetone solution for 24 hours to prepare RSC-PUA film. For the RSC-PUA composite film,the effects of PUA concentration and light curing time on the mechanical properties and the water absorption properties of composite films were investigated. The scanning electron microscopy(SEM),the X-ray diffraction(XRD),and the thermogravimetric analysis(TG-DTA) were used to detect the morphology and structure. The results showed that the optimal resin concentration was 30% and the light curing time was 120s. Under these conditions,the tensile strength and the elongation of the RSC-PUA composite film were 2.4 times and 6 times higher than those of the RSC film,respectively. Moreover,the water absorption rate of RSC-PUA film decreased by 53.6%,and the thermal degradation temperature increased to 113℃. These results showed that,when RSC film was reinforced by PUA,the mechanical properties,moisture resistance and thermal stability of the composite films were improved.