Characterization and biodegradability of foam based on coconut flesh waste-filled high density polyethylene

Abstract

Polymer foam biocomposites based on HDPE/coconut flesh waste were successfully produced by an extrusion foaming process. The compounding of the HDPE with coconut flesh waste was performed via a twin screw extruder which blends the materials with dicumyl peroxide (DCP) and chemical blowing agent (ADC). Five formulations with varying amount of coconut flesh waste were extruded at setting temperatures of 170°C at the melting zone whereas temperature of 190°C was set at the end of the die zone. This research studies the effect of different filler loading, the incorporation of DCP as crosslinking agent and ADC as the blowing agent on morphology (cell structure) of the foam samples. From the optical micrographs of Scanning Electron Microscope (SEM), it was obvious that closed-cell foams were developed. Plus, from the SEM images obtained it can also be concluded that as the filler loading increased, distorted and irregular cell geometry was formed. Density determination by Mettler Toledo Density Meter revealed that density increment was achieved by all foam samples as the filler content increased. From the Differential Scanning Calorimeter (DSC) result, it was noticeable that the percent of crystallinity decreases with increased in filler loading and the melting temperature of the biocomposites were not much affected by the incorporation of coconut waste. Finally, the additions of biodegradable coconut flesh waste into each formulation have significantly improved the biodegradability of these composites.