Thermoplastic and flexible films from arabinoxylan

Artikel i vetenskaplig tidskrift, 2019

Current interest in replacing fossil-fuel-derivedpolymers and materials in favor of renewable materials is high.An inherent difficulty with the use of biomass-derivedpolysaccharides and hemicelluloses in this context, however,is their stiffness and lack offlowability at temperatures relevantfor thermal processing, which severely limits their capacity forthermal processing. Here, we present a modification thatenables a heat-processable arabinoxylan (AX). The modifica-tion involves a ring-opening oxidation to a dialdehyde withsubsequent reduction of the aldehydes to alcohol, to increasethe number of OH groups, followed by an etherification withhydrophobic alkyl chains. The modified AX was successfullycompression molded with heat intofilmswhich becomethermoplastic in behavior and highlyflexibleandflows at temperatures above 130°C. Thefilms are stretchable up to 200%,and their strength and strain deformation are controlled by the degree of oxidation and substitution of the AX polymer. Thesefindings are highly encouraging and open up the potential use of modified AX alone or as a composite in applications thatincludefilms, food packaging, and barriers via hot-melt processing techniques.