Properties of biodegradable foam composites made from coconut residue as a function of the reinforcing phase of cassava starch

Abstract

The large amount of coconut residue produced by coconut producers and manufacturers has harmed the environment. Coconut waste was converted into coconut residue flour (CRF), which was used as a reinforcing material for biodegradable packaging development in order to decrease waste problems and increase the value of the circular economy. The effects of CRF content, ranging from 0 to 25 wt%, on the properties of foam-type composites made from cassava starch containing 10 wt% spent coffee grounds (SCG) were investigated. Flexural strength was raised to 2.53 MPa by adding CRF at 25 wt%. Athicker outer layer and denser foam structure were observed when the proportion of CRF in the samples was increased. The density of all samples was found to be 0.34-0.41 g/cm3, which was in the same range as other starch-based foam composites. The water resistance of the samples was marginally enhanced by adding more CRF. The water absorption index (WAI) and water solubility index (WSI) of the samples were in the ranges of 5.10–8.95% and 2.16–5.05%, respectively. The soil burial test at 30 days showed thatthe weight loss of the samples increased from 74.88 to 100% with increasing CRF due to the high susceptibility of CRF to microbial spoilage. Based on the findings of this study, CRF could bea promising and environmentally friendly reinforcing material for biodegradable foam composites that could be used to replace expanded polystyrene in dry food packaging. This would be a sustainable solution to waste problems while increasing financial gains for coconut producers and manufacturers.

Keywords

• foam composite
• biodegradable packaging
• soil burial
• coconut residue
• cassava starch