Investigation of the mechanical, thermal and wear properties of eggshell/PLA composites

Abstract

The current study investigated the potential application of agricultural waste chicken eggshell (CES) as a reinforcement in composites made of poly (lactic acid) (PLA). With the use of twin extruder and injection molding machine, polymer composites have been developed. The performance of the composites was assessed with respect to its mechanical, thermal, and wear properties. It was shown that the increase in eggshell content led to the increase in void content and water absorption. Despite the increase in void content, the mechanical properties, in particular, micro-hardness, tensile strength and flexural strength were significantly improved. Conversely, when the eggshell content increased from 0 to 30 wt%, the impact strength was decreased. A slight decrease in fracture toughness was observed. Thermal properties, such as thermal stability and thermal degradation temperature, were improved with an increase in eggshell content. PLA, PLA-CES-10, PLA-CES-20, and PLA-CES-30 composites exhibited increase in erosion rate by 13.8 %, 10 %, 9 %, and 6 %, respectively, when the impact velocity was increased from 30 m/s to 50 m/s. Data were analyzed statistically with one-way ANOVA and post hoc Tukey’s HSD test (α < 0.05). Overall, PLA/eggshell based polymer composites performed exceptionally well, in addition to their environmental benefits, pollution control, waste utilization, and reduced production cost.