Fast preparation of flexible wet-resistant and biodegradable films from a stable suspension of xylan/chitosan polyelectrolyte complexes

Abstract

Novel hemicellulose-based flms from polyelectrolyte complexes (PECs) of chitosan and xylan from sugar cane bagasse were prepared and characterized. PEC suspension from two diferent xylan to chitosan mass ratios (70/30 and 80/20) were considered. With the aim of shorten the whole flm preparation process, PEC suspension was concentrated through a fast evaporation stage before casting. Results show that the concentration stage did not modify neither the size of the complexes, i.e., a size distribution with a mode at 450 nm and other at 5000 nm, nor the mechanical properties of the flms. By the increment in xylan content from 70 to 80%, the strain at break was decreased (up to a value of 7%), the stress at break was increased (up to 22 MPa) and the swelling of the flms was increased from 80 to 90%. After 25 days under aerobic burial conditions, degradation of the flms was similar to cellulose.