Poly (vinyl alcohol) (PVA) possesses wide applications as food packaging materials, but is difficult to melt process for its strong inter/intra hydrogen bonding. In this work, flexible PVA films with different content of sorbitol plasticizers were prepared by melt processing with the assistance of water. And the influence of sorbitol plasticizer content on the crystallinity, optical transparency, water-retaining capability, mechanical properties, thermal stability and oxygen and water permeability were investigated. The results indicated that sorbitol dramatically improved the melt processing ability of PVA. Sorbitol could interact with PVA to form strong hydrogen bonding interactions, which would decrease the original hydrogen bonding of the matrix, resulting in the decrease of crystallinity degrees. The glass transition, melting and crystallization peak temperatures decreased with the increase of sorbitol. All the films exhibited fine optical transparency. The water retaining capability were improved with the increase of sorbitol. Especially, an increase in elongation at break and decrease in Young's modulus and tensile strength were observed indicating good plasticizing effect of sorbitol on PVA films. In addition, the PVA films prepared in this work exhibited fine barrier properties against oxygen and water, suggesting wide application potential as packaging materials.

中文翻译：

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山梨糖醇增塑剂对熔融加工聚乙烯醇薄膜结构和性能的影响

聚（乙烯醇）（PVA）作为食品包装材料具有广泛的应用，但由于其强的间/内氢键而难以熔融加工。在这项工作中，在水的辅助下通过熔融加工制备了具有不同山梨醇增塑剂含量的柔性 PVA 薄膜。并研究了山梨糖醇增塑剂含量对结晶度、透光性、保水能力、力学性能、热稳定性和透氧性和透水性的影响。结果表明山梨糖醇显着提高了PVA的熔融加工能力。山梨糖醇与PVA相互作用形成强氢键相互作用，使基体原有的氢键减少，结晶度降低。玻璃化转变，熔融和结晶峰温度随着山梨糖醇的增加而降低。所有膜都表现出良好的光学透明度。随着山梨糖醇的增加，保水能力提高。特别是，观察到断裂伸长率的增加和杨氏模量和拉伸强度的降低，表明山梨糖醇对 PVA 薄膜具有良好的增塑效果。此外，在这项工作中制备的 PVA 薄膜对氧气和水表现出良好的阻隔性能，表明其作为包装材料具有广泛的应用潜力。观察到的模量和拉伸强度表明山梨糖醇对 PVA 薄膜具有良好的增塑效果。此外，在这项工作中制备的 PVA 薄膜对氧气和水表现出良好的阻隔性能，表明其作为包装材料具有广泛的应用潜力。观察到的模量和拉伸强度表明山梨糖醇对 PVA 薄膜具有良好的增塑效果。此外，在这项工作中制备的 PVA 薄膜对氧气和水表现出良好的阻隔性能，表明其作为包装材料具有广泛的应用潜力。