油酸对壳聚糖/玉米醇溶蛋白复合膜液流变及膜性能的影响

为了提高壳聚糖/玉米醇溶蛋白膜的机械性能，将壳聚糖液与玉米醇溶蛋白液共混，向其中加入0%、15%、30%、45%（w/w）的油酸改性，研究膜液的粒径、zeta电位、静态和动态流变特性；然后，分析油酸添加量对膜阻隔性能，机械性能和相容性的影响。结果表明：添加油酸后，膜液体系粒径增大、分散均匀，添加30%油酸的膜液分散性更好，PDI为0.34，粒径为1307.5nm。随着油酸含量增大，膜液粘度减小，流动指数增大，弹性模量和粘性模量增加。OA-30膜机械性能较好，抗拉强度达到36.37MPa，断裂延伸率达到22.32%。膜的阻隔性增强，水蒸气、氧气透过率分别降低了44.21%和66.52%。复合膜中壳聚糖与玉米醇溶蛋白分子相容性好，表面光滑平整。综上所述，油酸改性改善了壳聚糖/玉米醇溶蛋白复合膜性能。

Effect of oleic acid on rheology of film solutions and film properties of chitosan/zein composite film

In order to improve the mechanical properties of chitosan/zein composite film, chitosan solution was mixed with zein. Oleic acid (0%, 15%, 30%, 45% (w/w)) as plasticizer was added to the mixture. The particle size, zeta potential, static and dynamic rheological properties of the blend solution were analyzed. Then the effects of oleic acid on the barrier properties, mechanical properties and compatibility of the film were evaluated. The results showed that the particle size of the blend solution increased due to the addition of oleic acid. Compared with other treatments, the dispersivity of particle was better in the solution with 30% oleic acid. The value of PDI was 0.34 and particle size was 1307.5nm. With the increase of oleic acid content, the viscosity of blend solution decreased and the flow index increased. Elastic modulus and viscosity modulus of the solution increased. The mechanical properties of OA-30 film were improved. The tensile strength was up to 36.37 MPa, and the fracture elongation was up to 22.32% The barrier of membrane was enhanced. The water vapor transmittance and oxygen transmittance was reduced by 44.21% and 66.52%. OA-30 film was flat, and the chitosan and zein molecules had good compatibility. In summary, oleic acid modification improved the properties of chitosan/zein composite film.