聚乳酸/茶多酚抗氧化膜的制备及其性能研究

以聚乳酸（PLA）为基材，茶多酚（TP）为抗氧化剂，通过流延法制备了具抗氧化活性的可降解PLA/TP共混膜，并研究了茶多酚添加量对共混膜包装性能及抗氧化性能的影响。研究结果表明：茶多酚与聚乳酸基质间发生了相互作用，茶多酚在聚乳酸基质中具有较好的分散性。天然抗氧化物茶多酚的添加使共混膜的拉伸强度、断裂伸长率以及透光率降低，但显著提高了共混膜的热封强度、透湿系数、透氧系数、溶解度和自由基清除率。当茶多酚的质量分数为0.9%时，共混膜的热封强度为3.31 N/(15 mm)，透湿系数和透氧系数分别是纯PLA膜的1.68倍和6倍，透光率为88.1%，自由基清除率为89.18%，是一种具有应用潜力的环境友好型食品活性包装材料。

Study on the Preparation and Performance of Polylactide Matrix Antioxidant Blend Films Based on Polyphenol

PLA/TP biodegradable blend film was prepared by choosing polylactide(PLA) as film forming substrate, and tea polyphenols(TP) as antioxidant. The effects of tea polyphenols content on the packaging properties and oxidation resistance of blend films were studied. The results showed that there were reactions between tea polyphenols and polylactic acid copolymer, and tea polyphenols had good dispersibility in polylactic acid matrix. The addition of tea polyphenols decreased the tensile strength, elongation at break and light transmittance of the blend films, but obviously improved the heat sealing strength, barrier property, oxidation resistance and free radical scavenging rate. When the mass fraction of tea polyphenols was 0.9%, the heat sealing strength of the blend film was 3.31 N/(15 mm), the coefficient of moisture and oxygen permeability were 1.68 and 6 times that of pure PLA respectively, the light transmittance was 88.1%, the free radical scavenging rate was 89.18%. The blend film has application potential in eco-friendly active food packaging material.