Electron beam pretreatment of carboxymethyl nanofibrillar cellulose reinforced polyvinyl alcohol-based degradable composite membranes: Preparation, characterization and property optimization

Abstract

This study investigated the development of biodegradable composite films blending carboxymethyl-modified peanut hull nanocelluloses (CMNCs) pretreated by electron beam irradiation with polyvinyl alcohol (PVA). The films were characterized by their structure, physicochemical properties, and degradation characteristics. The carboxyl group of CMNCs and the hydroxyl group of PVA enhance the network structure of the film through hydrogen bonding. This is most notably manifested in the fact that when CMNCs with a substitution degree of 0.38 and an addition amount of 4 % were added, the CMNCs were uniformly dispersed in the PVA matrix with a flat and smooth surface of the plastic and a dense structure. Meanwhile, the water contact angle (57.14°), the tensile strength (47.28 N/mm2) and elongation at break (156 %) of the composite films were significantly increased, and the water content (12.71 %) was decreased. The hydrophobic and mechanical properties of the composite plastics were improved considerably. In addition, the addition of 4 % CMNCs with a degree of substitution of 0.66 and a high dose of electron beam irradiation (120 KGy) to PVA made the degradation rate of the composite plastic in the first week (31 %) much higher than that of pure PVA (3 %). At the same time, the light transmittance of the composite plastic decreased significantly in both visible and UV ranges. EBI pretreatment significantly improved the degradation and light barrier properties of the composite plastics. Therefore, this study may provide new ideas for EBI pretreatment-assisted chemical modification of nanocellulose to prepare functional composite films.