Bionanocomposite Films Based on Chitosan with Bentonite Clay and Polyvinyl Alcohol

Nanocomposite films based on chitosan nanowhisker (CsW) with ionic and nonorganic polymers were prepared and studied on the swelling and mechanical properties. Сhitosan nanowhiskers were made from α-chitin by using a top-down approach. Ionic polymer polyvinyl alcohol (PVA) and nonorganic bentonite clay (BC) were employed to prepare chitosan nanowhisker bionanocomposite film taking into account their biocompatibility and nontoxicity. Fourier transform infrared spectroscopy analysis, swelling degree measurements and mechanical tests were employed to analyze the influence of significant PVA and bentonite amounts on the film properties. The mechanical strength was found to increase with the rise of the PVA concentration. This is an advantage for producing wound dressing material. The increase in BC concentration in the film resulted in high film stability in water and different mediums and in higher water absorbance than that of CsW/PVA film. However, the highest swelling degree was for a film of CsW itself but the mechanical strength was lower and insufficient to use it for the wound dressing material. Thus, the incorporation of PVA and BC into chitosan nanowhisker can enhance the swelling capacity and mechanical strength.