The Mechanical Properties of Thermoplastic Starch/Poly (Lactic Acid) Blends Filled Durian Peel Ash

Abstract

The purpose of this research was to study the mechanical properties of thermoplastic starch and poly (lactic acid) combined with durian peel ash at 0, 1.25, 2.50 and 5.00 %wt/wt of durian peel ash to polymer blend. The durian peel ash was made by dry grinding with the planetary ball mill. It was found that the particle size of the durian peel ash decreased from 29.21 ± 2.46 µm to 11.19 ± 0.62 µm after grinding for 1 h at 400 rpm. Thermoplastic starch and poly (lactic acid) combined with durian peel ash were prepared using an internal mixer and the test specimens were molded using a compression molding machine. Mechanical and morphological properties of thermoplastic starch and poly (lactic acid) combined with durian peel ash were studied. The highest tensile strength and elongation at break were exhibited in the specimen which had 1.25 %wt/wt of durian peel ash. Tensile strength and elongation at break decreased with an increase of durian peel ash. Young’s modulus and impact strength decreased with an increase of the amount of durian peel ash. The morphology of polymer blended with durian peel ash as captured by scanning electron microscopy (SEM) showed that thermoplastic starch and poly (lactic acid) were immiscible. Additionally, durian peel ash had a better distribution in thermoplastic starch than poly (lactic acid).