Hydroxyl crosslinking reinforced bagasse cellulose/polyvinyl alcohol composite films as biodegradable packaging

Abstract

To improve the packaging applicability of cellulose-based film, cellulose/polyvinyl alcohol (Cel/PVA) composite films were prepared via crosslinking the hydroxyl groups (-OH) among cellulose and PVA as well as the dehydration/etherification between -OH of adjacent PVA chains. The structure and morphology, mechanical/barrier properties, water resistance, food preservation and degradation behavior in soil of the films were comprehensively characterized. The results indicated that the cellulose-based film (Cel/PVA-10-H) containing 10% PVA thermal-treated at 165 ℃ possessed the best overall performance, which was mainly attributed to the crosslinked structure formed by the hydroxyl groups of cellulose and PVA. The tensile strength (TS) and elongation at break (EB) reached 77.17 MPa and 9.96%, respectively, which were approximately 220% and 97% higher than those of cellulose/PVA blend film without crosslinking. Moreover, the mechanical properties and oxygen permeability (2.04 × 10−5 cm3 mm−1 d−1 atm−1) of Cel/PVA-10-H film were less sensitive to high humidity (RH ≥ 80%), indicating that the cellulose-based composite crosslinked film possessed excellent water resistance. The results from cherry preservation and degradation tests in soil demonstrated that the as-prepared films kept the freshness of the fruits well and possessed excellent biodegradability.