聚乙烯醇/淀粉复合膜的制备及其对鲜花保鲜效果研究

Study on preparation of poly(vinyl alcohol)/starch composite films and its fresh-keeping effect on fresh flowers

以木薯淀粉和聚乙烯醇作为基本成膜物质,添加表面活性剂十二烷基磺酸钠,通过流延成膜法制备聚乙烯醇/淀粉复合膜。在单因素试验基础上,研究木薯淀粉、聚乙烯醇、表面活性剂十二烷基磺酸钠用量,成型加工温度和成型加工时间对聚乙烯醇/淀粉复合膜力学性能的影响,并通过正交试验对木薯淀粉、十二烷基磺酸钠用量和成型加工时间3个因素进行优化,确定聚乙烯醇/淀粉复合膜性能的较优工艺条件。同时,对新制备的复合膜土埋降解和鲜花保鲜性能进行了研究。结果表明:当聚乙烯醇用量为1 g,木薯淀粉用量为0.7 g,十二烷基磺酸钠用量为0.5 g,成型加工温度为80℃,成型加工时间为65 min时,制备的聚乙烯醇/淀粉复合膜力学性能较优,断裂伸长率高达262.58%、拉伸强度24.63 MPa。获得的新复合膜具有可降解性。聚乙烯醇/淀粉复合膜储藏80 h以后无霉菌生长迹象,对鲜花有一定保鲜效果。

Poly(vinyl alcohol)/starch composite films were prepared by means of a casting film-forming method using tapioca starch and poly(vinyl alcohol)as basic film-forming materials and sodium lauryl sulfonate as a surfactant.Based on single factor experiments,the effects of the amounts of tapioca starch,poly(vinyl alcohol)and surfactant sodium lauryl sulfonate,molding processing temperature,and molding processing time on the mechanic performance of the composite films were investigated.The three factors of tapioca starch dosage,sodium lauryl sulfonate dosage,and molding processing time were optimized through orthogonal experiments to determine the optimal processing conditions of the composite films.The soil degradation and fresh-keeping properties of the as-prepared composite films were studied.The results indicated that the composite films achieved optimal mechanical properties at a poly(vinyl alcohol)amount of 1 g,a tapioca starch amount of 0.7 g,a sodium lauryl sulfonate amount of 0.5 g,a molding processing temperature of 80℃,and a molding processing time of 65 min.The composite films exhibited high elongation at break of 262.58%and ultimate tensile strength of 24.63 MPa.The developed composite films obtained good degradability.There was no evidence of mold growth for the composite films after storage for 8 h,indicating a certain preservation effect on fresh flowers.