Preparation and characterization of bio-composite films obtained from coconut coir and groundnut shell for food packaging

A great deal of focus has been given to finding a bio-composite film to substitute petroleum-based synthetic plastic in recent years. Many animals in India die after eating the plastic-based film used to cover disposable food items such as sandwiches and burgers. An attempt is made in this paper to make a similar strength bio-composite film that is nature friendly and can substitute the plastic film. In this research, a novel bio-composite film is prepared from coconut coir (CC)/groundnut shell (GS) carboxymethyl cellulose (CMC)–starch and coconut coir (CC)/groundnut shell (GS) carboxymethyl cellulose (CMC)–commercial CMC and the physical, mechanical and microstructural properties of the resulting films are investigated. Coconut coir (CC) and groundnut shell (GS) are agricultural waste (lignocellulosic biomass), composed of cellulose, which can be further converted into carboxymethyl cellulose by mercerization followed by the etherification process and further that CMC is converted into a bio-composite film which can substitute the plastic film. Glycerol as a plasticizer makes film flexible, and olive oil enhances the water barrier properties. Film flexibility and extension usually improve with glycerol. Characterization of carboxymethyl cellulose has been done using XRD, FTIR spectra, and SEM. The antibacterial test was conducted against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Water solubility, moisture content, and film opacity improve with an increasing degree of substitution (DS). XRD, FTIR, and SEM results show that the CMCs have been successfully synthesized from coconut coir and groundnut shell. Bio-composite film produced from coconut coir CMC displays higher tensile strength and elongation.