Chitosan/nanocrystalline cellulose biocomposites based on date palm (Phoenix dactylifera L.) sheath fibers

Abstract

In this study, nanocrystalline celluloses were used to enhance physical, mechanical and water vapor barrier properties of chitosan films for potential food packaging applications. Two different mineral acids (sulfuric and phosphoric) were used to extract nanocrystalline cellulose from date palm sheath fibers. The influence of cellulose I and cellulose II on the properties of the isolated nanocrystalline celluloses (e.g., yield, energy and length of intra-and intermolecular hydrogen bonds, and degree of substitution) were studied too. The characteristics of chitosan biocomposite film with phosphorylated nanocrystalline cellulose were compared to those with sulfated nanocrystalline cellulose. Results showed that besides cellulose polymorphism, the ionic ester groups on the surface of nanocrystalline cellulose is one of the factors influencing the physical, chemical, mechanical, and water vapor barrier properties in chitosan/nanocrystalline cellulose biocomposites.