Production of biodegradable UV protection film using cellulose and lignin extracted from oil palm empty fruit bunch

Abstract

The optimized process for cellulose extraction from oil palm empty fruit bunch (EFB) consisting of acid pretreatment (0.5% (v/v) H2SO4), alkaline extraction (15% (w/w) NaOH), and chlorine-free bleaching (10% (w/v) H2O2) yielded pulp with the highest cellulose content at 83.42%. The EFB cellulose was then etherified into carboxymethyl cellulose (CMC) which was readily water-soluble (81.32%). The EFB CMC (2.5% (w/v)) was blended with glycerol (0.5 % (w/v)) to produce a composite film by a solution casting method. Lignin obtained from acid precipitation of the EFB black liquor was added into the film at different concentrations, and its influence on the UV-protection property was evaluated. Interestingly, the film without lignin incorporation completely blocked UV-B transmittance. The addition of lignin at all concentrations significantly improved the UV-A blocking and other physical properties, such as the surface roughness, thickness, and thermal stability, although the water vapor permeability and tensile strength were not significantly affected. The EFB CMC film supplemented with 0.2% (w/v) lignin was observed to be the optimized composition according to its total UV-A and UV-B protection capacity, highest antioxidant activity, and preferable mechanical performance.