Thermoplastic and Flexible Films from Arabinoxylan

Current interest in replacing fossil-fuel-derived polymers and materials in favor of renewable materials is high. An inherent difficulty with the use of biomass-derived polysaccharides and hemicelluloses in this context, however, is their stiffness and lack of flowability at temperatures relevant for thermal processing, which severely limits their capacity for thermal processing. Here, we present a modification that enables a heat-processable arabinoxylan (AX). The modification involves a ring-opening oxidation to a dialdehyde with subsequent reduction of the aldehydes to alcohol, to increase the number of OH groups, followed by an etherification with hydrophobic alkyl chains. The modified AX was successfully compression molded with heat into films—which become thermoplastic in behavior and highly flexible—and flows at temperatures above 130 °C. The films are stretchable up to 200%, and their strength and strain deformation are controlled by the degree of oxidation and substitution of the AX polymer. These findings are highly encouraging and open up the potential use of modified AX alone or as a composite in applications that include films, food packaging, and barriers via hot-melt processing techniques.