Investigating the influence of periwinkle shell powder on the thermal and mechanical performance of high-density polyethylene composites

Abstract

In this study, the shell powder of Littorina littorea commonly called periwinkle was used as an eco-friendly filler in High-Density Polyethylene (HDPE) to form periwinkle/HDPE composites (PHPC). Understanding the effect of different particle sizes of periwinkle shell powder (PSP) and optimizing their influence on PHPC is the main scope of this work. Periwinkle shell (PS) particles with sizes ranging from <53 μm to 150 μm were chosen as reinforcements. The PSP sizes chosen in this study, <53 μm, 53 μm, 75 μm, 90 μm, 105 μm and 150 μm were named PHPC _L53 , PHPC _53 , PHPC _75 , PHPC _90 , PHPC _105 , and PHPC _150 , respectively. The composites were fabricated by incorporating 1 wt% PSP into the HDPE matrix using the compression molding technique and then subjected to morphological, thermal, and mechanical characterizations. Morphology studies using scanning electron microscopy (SEM) confirms 150 μm PSP had the best dispersion whereas 75 μm PSP resulted in agglomeration. PSP had little influence on the thermal stability of HDPE except for PHPC _150 which showed an increase in the degradation temperature when compared to the virgin sample. Mechanical properties such as hardness, Young’s modulus, impact strength, and flexural modulus were enhanced by the addition of PSP. However, a decrease was noted in the elongation at break (%) and flexural strength of PHPC indicating the stiffening effect of the filler on the HDPE. In order to understand the particle size influence better, the extension evaluation method (EEM) was used for all samples and PHPC _150 was found to be the best performing among all particle sizes.

Keywords

• periwinkle shell powder
• HDPE
• composites
• eco-benign filler
• extension evaluation method