Bionanocomposites of thermoplastic starch reinforced with nanostructured cellulose for application in wound dressings

Abstract

The choice of materials used in the production of wound dressings is important as it affects the well-being and recovery of patients. The selection of natural, renewable and biodegradable materials can also help reduce the environmental impact of these dressings. In this context, biopolymers such as starch and cellulose are promising raw materials. In this work, thermoplastic starch bionanocomposites reinforced with nanostructured cellulose (NC) and functionalized cellulose (NCf) through oxidation using TEMPO (N-oxyl-2,2,6,6-tetramethylpiperidine) were developed, aiming for application in wound dressings. The bionanocomposites were prepared with 5wt% starch, 5wt% glycerol and 1wt% nanocellulose, and the films were processed using the tape casting technique, aiming for large-scale production. The raw materials and bionanocomposites were evaluated using FTIR, SEM, AFM, XRD, tensile tests and contact angle measurements. Homogeneous, continuous and transparent films with a thickness of 0.20 mm were obtained. It was observed that the bionanocomposites showed an increase of more than 94% in tensile strength and 150% in maximum deformation, compared to starch films without nanostructured cellulose. The Young’s modulus and maximum tensile strain values of the develop bionanocomposites are comparable to other results reported in the literature for films with potential application in dressings. Furthermore, significant increases in the mechanical properties of starch-based bionanocomposites were observed with the addition of only 1 wt% of nanostructured cellulose. These results suggest that the bionanocomposites developed in this work have potential for use in wound dressings, once their composition is optimized.