Preparation of Cellulose Nanocrystals Biofilm from Coconut Coir as an Alternative Source of Food Packaging Material

Abstract

The current perspective emphasizes on the synthesis of a biofilm from cellulose nanocrystals (CNC) of coconut coir for the development of sustainable packaging materials as an alternative source of plastic. The biofilm was prepared by a solvent-casting method and investigated by various analytical techniques. Of them, surface morphology was observed by SEM, suggesting a crystalline rod shape with particle size of 104-318 nm and diameter of 15-70 nm. However, CNC was incorporated with starch at various ratios ranging from 10:0 to 1:9; the ratio 6:4 of CNC and the binder maximized the mechanical properties of the polymer. In the presence of a plasticizer and a cross-linker, the film possessed high tensile strength (38.4 ± 1.57 MPa) and elongation (8.2 ± 0.39%) compared to commercially available polyethylene (9.84 ± 0.32 MPa and 23 ± 0.74%). The biofilm possessed a great extent of cross-link structure, divulging through the change of contact angle (92°), surface morphology (rough surface), crystallinity (45.36%), water vapor transmission rate (427 g/m2/day), and thermal stability from 232 to 258 °C. The degree of deterioration was assessed by the soil burial test (30-45 days), highlighting the environmental compatibility of the film.