Abstract:

The objective of this study was to investigate the effects of plasticizer type (glycerol，oleic acid and polyethylene glycol) and plasticizer quantity on the surface and mechanical properties of cast zein film.Additionally，the viscosity of the zein-forming solution and the water absorption，surface microstructure of plasticized zein films were analyzed and compared.The data showed that，the oleic acid-plasticized solution possessed the highest viscosity while the glycerol-plasticized one had the lowest viscosity by zein-plasticizer interactions.The surface microstructure of zein films were affected and the water absorption capacity of zein-based film was dependent on the hydrophilic/hydrophobic plasticizer used，and decreased in the order of glycerol-plasticized film，polyethylene glycol plasticized-film and oleic acid plasticized-film.In the case of oleic acid-and polyethylene glycol-plasticized films，the initial contact angles with water or alcohol increased with increasing plasticizer quantity，while the glycerol-plasticized films showed a different pattern.The data of dynamic contact angle were well fitted with exponential equation，and the decreasing rate of contact angle was a function of time in a plasticizer type-dependent manner，and decreased in the order of glycerol-plasticized film，polyethylene glycol plasticized-film，oleic acid plasticized-film.The tensile strength (TS) of polyethylene glycol plasticized-film decreased with increasing plasticiser quantity，while a dramatic increase in elongation at break (EB) occurred.This data indicated that polyethylene glycol was an effective plasticizer for zein-based film.While，only a slight increase in EB was observed for glycerol-plasticized film and oleic acid plasticized-film with increasing plasticizer quantity.

Key words:

玉米醇溶蛋白膜, 塑化剂, 黏度, 微结构, 表面性质, 机械性质

摘要：

研究了塑化剂种类（甘油、油酸和聚乙二醇）、用量对玉米醇溶蛋白（zein）膜表面和机械特性的影响及塑化剂对zein成膜液黏度、成膜后表面形貌、水分吸附特性的影响。结果表明：含油酸的成膜液黏度最大，含甘油的成膜液黏度最小，成膜后表面呈现不同的形貌图;蛋白膜的水分吸附特性与塑化剂亲水性变化趋势一致，随甘油、聚乙二醇和油酸顺序而下降;油酸和聚乙二醇塑化的zein膜的表观接触角随塑化剂含量的增加而增加，甘油膜却呈相反趋势;蛋白膜表面润湿动力学可用指数方程模型表征，动态接触角变化速率表现为甘油膜＞聚乙二醇膜＞油酸膜;随塑化剂含量增加，聚乙二醇蛋白膜抗拉强度（TS值）下降，延伸率（EB值）却急剧增加，甘油和油酸蛋白膜的TS值和EB值具有相同的变化趋势但效果不明显。

关键词:

玉米醇溶蛋白膜, 塑化剂, 黏度, 微结构, 表面性质, 机械性质