Tian Huafeng, Yan Jiaan, Rajulu A Varada, Xiang Aimin, Luo Xiaogang
School of Material and Mechanical Engineering, Beijing Technology and Business University, Beijing 100048, China; Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, China.
School of Material and Mechanical Engineering, Beijing Technology and Business University, Beijing 100048, China.
Int J Biol Macromol. 2017 Mar;96:518-523. doi: 10.1016/j.ijbiomac.2016.12.067. Epub 2016 Dec 26.
In this work, starch/polyvinyl alcohol (PVA) blend films with different compositions were prepared by melt processing. The effect of the composition and relative humidity (RH) on the structure and properties of the resulting blends were investigated. OH groups on starch and PVA formed hydrogen bonding interactions, which could improve the compatibility of the two components. With the increase of starch, the degree of crystallinity of PVA component decreased. The fracture surface of the blend films exhibited rough surface, suggesting the tough fracture. With the increase of starch, the water uptake at equilibrium decreased. With the increase of RH, the water uptake at equilibrium of the resulting blends increased. The tensile strength, elongation at break and Young's modulus decreased with increasing content of starch. However, at 50% starch content, the flexibility of the blend films was still high, with the elongation at break more than 1000% and tensile strength of 9MPa, which was superior to the commonly LDPE package films. The tensile strength and Young's modulus decreased with the increase of RH, while the elongation at break was enhanced dramatically, indicating the improved flexibility. Therefore, these kinds of blend films exhibited wide application potentials as packaging materials.
在本工作中，通过熔融加工制备了不同组成的淀粉/聚乙烯醇（PVA）共混薄膜。研究了组成和相对湿度（RH）对所得共混物结构和性能的影响。淀粉和PVA上的羟基形成氢键相互作用，这可以提高两种组分的相容性。随着淀粉含量的增加，PVA组分的结晶度降低。共混薄膜的断裂表面呈现粗糙表面，表明为韧性断裂。随着淀粉含量的增加，平衡吸水率降低。随着RH的增加，所得共混物的平衡吸水率增加。拉伸强度、断裂伸长率和杨氏模量随着淀粉含量的增加而降低。然而，在淀粉含量为50%时，共混薄膜的柔韧性仍然很高，断裂伸长率超过1000%，拉伸强度为9MPa，优于普通的低密度聚乙烯包装薄膜。拉伸强度和杨氏模量随着RH的增加而降低，而断裂伸长率显著提高，表明柔韧性得到改善。因此，这类共混薄膜作为包装材料具有广阔的应用潜力。
