豌豆淀粉/聚乳酸双层膜的制备与性能表征

采用溶液流延法以豌豆淀粉（PS）和聚乳酸（PLA）为原料制备了豌豆淀粉/聚乳酸（PS/PLA）双层薄膜。通过对双层薄膜的吸水性、溶解性、水蒸气透过性、拉伸性能、表面形貌等进行测试，研究了薄膜的力学性能、疏水性能以及水蒸气阻隔性能。结果表明：随着双层膜中聚乳酸层的比例增加，双层薄膜的吸水性、溶解性和水蒸气透过性逐渐降低，拉伸强度和拉伸模量逐渐增加，断裂伸长率逐渐下降，表明水蒸气阻隔效果明显，增加了膜的韧性，降低了膜的强度。当PLA和PS的质量比为50：50时，PS/PLA双层膜的拉伸强度为（13.47±0.75）MPa，拉伸模量为（0.848±0.002）GPa；断裂伸长率为（16.11±0.16）%，水蒸气透过系数为0.27×10^-10 g·cm/（cm²·s·Pa）。

Preparation and Characterization of Pea Starch/Polylactic Acid Double Layer Film

The pea starch/polylactic acid(PS/PLA) double layer film was prepared by solution casting method with pea starch(PS) and polylactic acid(PLA) as raw materials. The mechanical properties, hydrophobicity and water vapor barrier properties of the films were studied by testing the water absorption, solubility, water vapor transmission performance, tensile properties and surface morphology of double layer films. The results showed that with the increase of the proportion of polylactic acid layer, the water absorption, solubility and water vapor permeability of double layer film decreased, the tensile strength and tensile modulus increased, the elongation decreased gradually, which indicated that the water vapor barrier effect was obvious, the toughness increased and the strength reduced. When the mass ratio of PLA and PS was 50:50, the tensile strength, tensile modulus, elongation at break of PS/PLA double layer were (13.47±0.75)MPa, (0.848±0.002)GPa, and (16.11±0.16)%, respectively; and the water vapor transmission coefficient was 0.27×10^-10 g·cm/(cm²·s·Pa).