Converting coconut meal into biothermoplastics for industrial applications

Abstract

We present a simple approach to convert coconut (copra) oil cake into biothermoplastics with properties that are suitable for replacing synthetic polymer‐based plastics in current use. About 1.9 million tons of copra meal are generated ever year as coproducts and are available at $0.50–$0.60 per kilogram, making it a renewable, sustainable and low‐cost raw material. Despite containing proteins, carbohydrates and oil, there are limited non‐food applications of oil meals since most oil meals are typically non‐thermoplastic and hence difficult to be processed into bioproducts. In this study, we report the processing of copra meal into biothermoplastics in the presence of various plasticizers, heat and pressure. Compression molded films and bioproducts were developed from copra meal by heating at 130°C in the presence of glycerol, coconut oil or cashew shell oil as plasticizer. The films obtained had tensile strength of up to 4.4 MPa and were inherently stable in water. A one‐step crosslinking with citric acid was done to further improve the strength and stability of the films. With large availability at low cost, copra meal provides an opportunity to develop low‐cost, biodegradable, edible and innovative bioproducts that have the potential to replace the synthetic polymer‐based plastics in current use, particularly single‐use plastics.

Copra Meal: A Review of Its Production, Properties, and Prospects

“…The potential replacement of single-use synthetic polymer-based plastics with cheap and biodegradable thermoplastics made from coconut meal has been recently studied by Reddy et al [ 86 ]. Since copra meal, just like other oil meals, is non-thermoplastic in nature, varying types and ratios of plasticizers were added to enable thermal processing before the meal was subjected to compression molding and rendered into biofilms.…”