Chitosan biocomposites with enzymatically produced nanocrystalline cellulose

Several fungal and bacterial strains are known to be able to degrade polymeric chains of cellulose. In this research, two polymorphic forms of celluloses, Cellulose I (C I) and Cellulose II (C II), were incubated with Ochrobactrum anthropi strain producing the cellulolytic enzymes. In the result, nanocrystalline celluloses with distinctive particle sizes distributions, as well as intact supermolecular and chemical structures were produced. The differences in yield of nanometric particles of each polymorphic form were discussed in accordance to crystallographic form of cellulose. Solvent casting method was applied to produce chitosan films filled with 1, 3, and 5 wt% of nanocrystalline C I and nanocrystalline C II. Mechanical testing proved that the tensile properties of the composites were closely related to the polymorphic variety of nanocrystalline cellulose. On the other hand, SEM microphotographs of the produced composites confirmed that good distribution of nanoparticles in the chitosan matrix was crucial for obtaining materials with enhanced mechanical properties. Filling the chitosan matrix with 1 wt% of nanocrystalline C I was determined to be the most effective. POLYM. COMPOS., 39:E448–E456, 2018. © 2017 Society of Plastics Engineers