Crosslinked lignin-starch polymers with alternative applications

Abstract

Lignin is a complex biopolymer obtained as a by-product from the delignification of wood and grasses. Starch is also a natural polymer of amylose and amylopectin found in many plants, featuring a relatively simple structure and limited solubility in water. Lignin and starch are abundant and inexpensive biopolymers that are often considered sustainable alternatives to oil-based and synthetic polymers. Despite their abundance, and owing to their physicochemical properties, starch and lignin have limited usages as their pristine forms in industrial, high-performance, and food applications. In the last ten years, studies regarding the combination of starch and lignin for producing reinforced materials such as films, coatings, and adhesives have increased significantly. The incorporation of lignin into starch matrices produced materials that were more resistant to water, UV radiation, mechanical stress, and thermal changes. This thesis explores the state of the art for the production of starch-lignin materials, focusing on the physicochemical properties of the starch-lignin materials and the outcomes, challenges, and opportunities for this field. [...]