不同抗氧化剂对聚乙烯醇复合膜性能的影响

Effects of Different Antioxidants on Properties of PVA Composite Films

中文关键词: 聚乙烯醇  茶多酚  抗氧化剂  力学性能  自由基清除率

英文关键词: polyvinyl alcohol  tea polyphenols  antioxidants  mechanical properties  free radical scavenging rate

中文摘要:

      目的 利用不同水溶性及脂溶性抗氧化剂对聚乙烯醇（PVA）进行改性，以期在改善复合膜综合性能的基础上，重点提升其抗氧化能力。方法 以茶多酚、柠檬酸、BHT和维生素E为变量，甘油/聚乙烯醇为基底，研究不同水溶性及脂溶性抗氧化剂对复合膜形貌、力学性能、透光性、耐水性能及抗氧化能力的影响。结果 加入适量的抗氧化剂后，薄膜各项性能均有所增强。其中，茶多酚/聚乙烯醇复合膜的力学性能最优，茶多酚（1.5%）/PVA复合膜的拉伸强度可达47.85 MPa，断裂伸长率为375.69%。该复合膜显著提高了紫外线的吸收率，同时73.93%的自由基清除率为研究薄膜中最高。结论 采用茶多酚改性聚乙烯醇，不仅可提升复合膜的包装强度，增强其耐水性能，更能增强抗氧化能力，为食品保鲜提供了良好思路。

英文摘要:

      The work aims to modify the polyvinyl alcohol (PVA) with different water-soluble and fat-soluble antioxidants in order to improve the antioxidant properties of the composite film on the basis of enhancing its comprehensive performance. With tea polyphenols, citric acid, BHT and vitamin E as variables and glycerol/polyvinyl alcohol as basis, the effects of different water-soluble and fat-soluble antioxidants on the morphology, mechanical properties, light transmittance, water resistance and antioxidant capacity of the composite film were studied. The properties of the films were enhanced by adding proper amount of antioxidant. The mechanical properties of tea polyphenols/polyvinyl alcohol composite film were the best. The tensile strength of tea polyphenols (1.5%)/PVA composite film could reach 47.85 MPa and the breaking elongation rate was up to 375.69%. The composite film could significantly improve the UV absorption rate, and the free radical scavenging rate of 73.93% was the highest among all the studied films. Using tea polyphenol to modify polyvinyl alcohol can not only improve the packaging strength of composite film and enhance its water resistance, but also strengthen its antioxidant and antibacterial properties, providing a good idea for food preservation.