Thermal and mechanical properties of polyethylene-starch based film incorporated with crude palm oil

Abstract

The present study reports the changes in thermal degradation, thermal properties, and mechanical performance of polyethylene (PE) - thermoplastic starch (TPS) based film incorporated with crude palm oil (CPO) as a plasticizer. The films were prepared using the melt-blending and hot-press technique. Then, it was characterized using a Thermogravimetric analyzer, Differential Scanning Calorimetry, and Universal Testing machine to determine the film’s thermal degradation, thermal properties, and mechanical properties. TPS in PE film had reduced the thermal stability; however, CPO gives small changes to it. The amorphous phase of TPS reduced PE film’s crystallinity. Besides, CPO provided a lubricating effect and improved the crystallinity of PE/TPS film. Unfortunately, the tensile strength and elongation at break keep decreased with an increase of CPO content. The thermal decomposition and kinetic analysis using a thermogravimetric analyzer on one film (PE/TPS/CPO) at three different heating rates (7.5, 10.0, and 12.5 °C/min) were investigated. Friedman isoconversional model-free method was used to calculate the activation energy of the film. The thermal decomposition of materials in the film increased with the increasing heating rate, and the average computed activation energy obtained was 364.68 kj/mol.