Robust, Flexible, and High-Barrier Films from Bacterial Cellulose Modified by Long-Chain Alkenyl Succinic Anhydrides

This paper describes a simple and low-pollution surface modification strategy for fabricating flexible, semi-transparent, and robust bacterial cellulose (BC)/Kombucha tea-based BC films that are effectively resistant to water, water vapor, oxygen, ultraviolet light, and foodborne pathogenic bacteria. The strategy uses dimethyl sulfoxide as the pre-swelling solvent and long-chain alkenyl succinic anhydrides with different chain lengths as the esterifying agents. The proof of esterification, crystallinity index, film microstructure, and degree of surface substitution were systematically investigated. Our result showed that acylation with 2-octenylsuccinic anhydride for 8 h conferred the BC films with the highest water-vapor/oxygen resistance and optimal mechanical/thermal properties. In addition, the modified BC film has good antimicrobial properties and is capable of wrapping strawberries, increasing their longevity. Biodegradation and alkaline hydrolysis tests demonstrated that compostability of the film and recycling of the BC pulp are possible, revealing that such high-performance biofilm-based food packaging could have a green life cycle.