Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Frederiksberg, Denmark.
Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark.
Int J Mol Sci. 2017 Sep 30;18(10):2075. doi: 10.3390/ijms18102075.
Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material.
生物塑料和生物材料由天然或生物量衍生的聚合物组成，提供了解决当前环境问题的解决方案。基于多糖的生物塑料因其固有可生物降解性而成为传统塑料的重要替代品。仅含有直链淀粉的（AO）是一种经过工程改造的大麦淀粉，直链淀粉含量为 99%，它被用来生产交联的全天然生物塑料，以普通的大麦淀粉作为对照。甘油被用作增塑剂，柠檬酸交联被用来改善交联 AO 淀粉挤出物的机械性能。挤出过程将对照淀粉从 A 型转变为 Vh 和 B 型晶体，表明原淀粉颗粒中的淀粉晶体完全熔融。交联的 AO 和对照淀粉样品显示出额外的宽角度衍射反射。与 Vh 型单螺旋体复合的磷脂构成了 AO 淀粉样品的一个组成部分。对选定的淀粉基原型进行的气体渗透性测试表明，其性能与商业 Mater-Bi 塑料相当。交联的 AO 原型与对照品具有相同的堆肥特性，这表明改性淀粉的行为与普通淀粉相同。这些数据表明，使用设计淀粉作为原料生产全天然生物塑料是可行的。
