Chemical Engineering Department, University of Alicante, Apartado 99, 03080 Alicante, Spain.
Chemical Engineering Department, University of Alicante, Apartado 99, 03080 Alicante, Spain.
Int J Biol Macromol. 2019 Aug 15;135:845-854. doi: 10.1016/j.ijbiomac.2019.06.004. Epub 2019 Jun 3.
Starch films are gaining attention as substitutes of synthetic polymers due to their biodegradability and low cost. Some ionic liquids have been postulated as alternatives to glycerol, one of the best starch plasticizers, due to their great capacity to form hydrogen bonds with starch and hence great ability of preventing starch retrogradation and increasing film stability. In this work, [emim][Ac]-plasticized starch films were prepared from potato, corn and wheat starch. The effect of starch molecular structure in terms of granular composition (amylose and phosphate monoester contents) and molecular weight (M) on film properties was evaluated. Potato starch films were the most amorphous because of the higher M and phosphate monoester content of potato starch, both contributing to a lower rearrangement of the starch chains making the crystallization process difficult. In contrast, corn and wheat starches lead to more crystalline films because of their lower M, which may imply higher mobility and crystal growth rate, and lower phosphate monoester content. This more crystalline structure could be the responsible of their better mechanical properties. [emim][Ac] can be considered suitable for manufacturing starch films showing corn and wheat starch films similar properties to synthetic low-density polyethylene, but involving a simple and environmentally-friendly process.
淀粉薄膜因其可生物降解性和低成本而受到关注，正在逐渐成为合成聚合物的替代品。一些离子液体由于其与淀粉形成氢键的能力很强，从而能够很好地防止淀粉回生，提高薄膜稳定性，被认为是甘油（最好的淀粉增塑剂之一）的替代品。在这项工作中，使用马铃薯、玉米和小麦淀粉制备了[emim][Ac]增塑淀粉薄膜。评估了淀粉分子结构（直链淀粉和磷酸单酯含量）和分子量（M）对薄膜性能的影响。由于马铃薯淀粉的 M 和磷酸单酯含量较高，马铃薯淀粉的薄膜最无定形，这都有助于降低淀粉链的重排，使结晶过程变得困难。相比之下，由于玉米和小麦淀粉的 M 较低，可能意味着其流动性和结晶生长速率较高，且磷酸单酯含量较低，这导致了更结晶的结构，从而使它们具有更好的机械性能。[emim][Ac]可以被认为是适合制造淀粉薄膜的物质，所制得的玉米和小麦淀粉薄膜具有类似于低密度聚乙烯的性质，但涉及到简单且环保的工艺。
