Biodegradable Films Formed by Polyelectrolyte Complexes of Xylan and Chitosan

GALVÁN, MARÍA V.; SCHNELL, CARLA N.; INALBON, MARÍA C.; PERESÍN, MARÍA S.; ZANUTTINI MIGUEL A.; MOCCHIUTTI PAULINA

Concepción

Simposio; 3er Congreso Iberoamericano sobre Biorrefinerías (CIAB), 4to Congreso Latinoamericano sobre Biorrefinerías y 2do Simposio Internacional sobre Materiales Lignocelulósicos; 2015

UDT y CB U. de Concepción, SIADEB, U. de Jaén, LNEG, PROVALOR CYTED, RIADICYP, VTT, BIOREN U. de la Frontera

The objective of this work was to obtain potentially useful biodegradable films by using natural polyelectrolyte complexes (PECs) obtained by combining anionic xylan (Xyl) and cationic chitosan (Ch) solutions. The effects of different mass ratios of polyelectrolytes (30% Ch:70% Xyl; 25% Ch:75% Xyl; 20% Ch:80% Xyl and 15% Ch: 85%Xyl) with 10% glycerol as plasticizer were evaluated.Polyelectrolytes were characterized by determining the charge density, molecular weight and degree of deacetylation of chitosan. Taking into account these results, PECs were prepared by adding the anionic Xyl on the cationic chitosan solutions, which is under continuous stirring, at pH 5.0 and 0.01N NaCl. It was found that the low charge densities of the different complexes obtained were always positive.Films were produced by casting the suspensions of PECs. Solubility, mechanical properties, water vapor transmission rate (WVTR) and oxygen permeability were evaluated. The results show that the lowest value of solubility, WVTR and oxygen permeability was found in the case of the film with higher amount of xylan. The mechanical properties of the films depended on the proportion of Ch:Xyl used. When increasing the amount of chitosan in the films, the stress at break and the Young´s modulus were observed to decreased, whereas the opposite effect was observed in the case of strain at break.