Biobased films prepared from NaOH/thiourea aqueous solution of chitosan and linter cellulose

Abstract

In the present study, films based on linter cellulose and chitosan were prepared using an aqueous solution of sodium hydroxide (NaOH)/thiourea as the solvent system. The dissolution process of cellulose and chitosan in NaOH/thiourea aqueous solution was followed by the partial chain depolymerization of both biopolymers, which facilitates their solubilization. Biobased films with different chitosan/cellulose ratios were then elaborated by a casting method and subsequent solvent evaporation. They were characterized by X-ray analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), thermal analysis, and tests related to tensile strength and biodegradation properties. The SEM images of the biofilms with 50/50 and 60/40 ratio of chitosan/cellulose showed surfaces more wrinkled than the others. The AFM images indicated that higher the content of chitosan in the biobased composite film, higher is the average roughness value. It was inferred through thermal analysis that the thermal stability was affected by the presence of chitosan in the films; the initial temperature of decomposition was shifted to lower levels in the presence of chitosan. Results from the tests for tensile strength indicated that the blending of cellulose and chitosan improved the mechanical properties of the films and that an increase in chitosan content led to production of films with higher tensile strength and percentage of elongation. The degradation study in a simulated soil showed that the higher the crystallinity, the lower is the biodegradation rate.

Novel antimicrobial chitosan–cellulose composite films bioconjugated with silver nanoparticles

“…Chitosan is non-toxic, has high antimicrobial activity, and has been widely used as wound dressing material (Hou et al, 2008;Alonso et al, 2009;Pandima Devi et al, 2012). Recently, chitosan/cellulose blend membranes were prepared to improve the antimicrobial properties of cellulose-based membranes (Shih et al, 2009;Morgado et al, 2011;Stefanescu et al, 2012). However, monocomponent antibacterial agents have been far from meeting requirements for some special conditions.…”

Saccharification of Brazilian sisal pulp: evaluating the impact of mercerization on non-hydrolyzed pulp and hydrolysis products

“…The degree of polymerization and the average molar mass of cellulose were determined as previously described (Morgado et al 2011, TAPPI T230 om-2008. All measurements were made in triplicate.…”

Manufacture and performance of ethylamine hydroxyethyl chitosan/cellulose fiber in N -methylmorpholine- N -oxide system

“…Among these polymer blends, chitosan/cellulose blend is one of the most promising materials because of the abundance of cellulose and chitin which is parent polymer of chitosan. Numerous investigations have been carried out about chitosan/cellulose blends, which seem to be proper to prepare antibacterial Lyocell fibers [13][14][15][16].…”