Development of Nanocomposites from Bacterial Cellulose and Poly(vinyl Alcohol) using Casting-drying Method

Nanocomposites of bacterial cellulose (BC) and poly(vinyl alcohol) (PVA) were prepared by cast-drying method as an easy way in producing nanocomposite films and to expand the use of BC. The contribution of PVA in nanocomposites was evaluated by measurement of cross-sectional surface, moisture uptake and mechanical properties. Morphological analysis shows that PVA covered a number of cellulosic fibres and formed denser material as a function of PVA addition. Based on the tensile test, the addition of PVA causes a very slight reduction compared with bacterial cellulose itself. The BC/PVA nanocomposites still have similar stiffness to BC with elongation at break less than 5%, while PVA film shows ductile properties with elongation at break more than 80%. On the other hand, the presence of BC fibres in the PVA matrix enhanced the tensile strength and the elastic modulus of pure PVA about two to three times, but it decreased the toughness of pure PVA. The highest tensile strength and elastic modulus of the nanocomposites are 164 MPa and 7.4 GPa, respectively at BC concentration of 64%. Increasing BC concentration is proportional to reducing moisture uptake of BC/PVA nanocomposites indicating that the existence of BC fibres inhibits moisture absorption.