The Influence of Starch Origin on the Properties of Starch Films: Packaging Performance

The films were made from various starches such as that from maize, potato, oat, rice, and tapioca using 50%w of glycerine as a plasticizer. The obtained starch-based films were made using the well-known casting method from a starch solution in water. The properties of the films that were evaluated were tensile strength, water vapour transition rate, moisture content, wetta-bility, and their surface free energy was determined. Surface free energy (SFE) and its polar and dispersive components were calculated using the Owens-Wendt-Rabel-Kaelbe approach. The values of SFE in the range of 51.64 to 70.81 mJ∙m−2 for the oat starch-based film and the maize starch-based film. The films revealed worse mechanical properties than those of conventional plastics for packaging purposes. The results indicated that the poorest tensile strength was exhibited by the starch-based films made from oat (0.36 MPa) and tapioca (0.78 MPa) and the greatest tensile strength (1.49 MPa) from potato.

本研究以玉米、马铃薯、燕麦、大米及木薯等多种淀粉为原料，以50%质量分数的甘油作为增塑剂，采用淀粉水溶液流延法制备得到淀粉基薄膜。对所获薄膜的拉伸强度、水蒸气透过率、含水率与润湿性进行了表征，并通过Owens-Wendt-Rabel-Kaelbe法计算其表面自由能（Surface Free Energy, SFE）及其极性、色散分量。结果显示，燕麦淀粉基薄膜与玉米淀粉基薄膜的表面自由能介于51.64~70.81 mJ·m⁻²区间。相较于包装用传统塑料薄膜，本研究制备的淀粉基薄膜力学性能较差。测试表明，燕麦淀粉基薄膜（0.36 MPa）与木薯淀粉基薄膜（0.78 MPa）的拉伸强度最低，而马铃薯淀粉基薄膜的拉伸强度最高，可达1.49 MPa。