An unconventional approach for improving the integrity and mechanical properties of xylan type hemicellulose based films

Abstract

The isolation of xylans from lignocellulosic biomass via alkaline extraction typically involves a neutralization step, which results in salt formation. Usually, these salts are removed from the medium to avoid their presence within the isolated xylans and films made from these polymers. The present work shows that it is not always necessary to do so, since the presence of potassium acetate (KAcO) in the films was found to be beneficial both for the film formation and mechanical properties. While desalted xylans could only form film fragments, the presence of KAcO in the films led to intact films with increased toughness by approximately 2 to 5 fold. Increasing KAcO concentration resulted in softer films while the opposite was true for NaCl indicating that the two salts had different effects on the films, which was also verified by the differences in the cross-sectional and surface morphologies of the films containing KAcO and NaCl.