Comparative Analysis of Characteristics of Poly‐Lactic Acid (PLA) Bio‐Composites Blended With White Marble and Walnut Shell Fine Powder

ABSTRACT The development of eco‐friendly materials with superior properties is challenge for many researchers. The polymer composites of PLA has certain limitations related to heat resistance, impact strength, etc. This research work is related to use of bio waste fillers to improve properties of PLA. The work carried out consists of walnut shell fine dust powder (WSFP) and white marble fine powder (WMFP) for reinforcement. The PLA polymer is reinforced using fine powder of walnut shell and white marble having blending contribution as 2.5%, 5%, 7.5%, and 10% with respect to PLA matrix individually. Four types of filaments were extruded for each type of filler using a single screw extruder. The testing specimens were printed using commercial 3D printer and tested for hardness (Shore D), melting temperature, elongation, tensile, flexural strength and water absorption. The hardness of PLA decreased for walnut shell filler but improvement in hardness about 10% is observed for white marble powder filler. Slight improvement in melting point for both type of fillers. The tensile strength is improved when walnut shell fine powder added to 7.5% of WSFP while it is declined with addition of white marble fine powder (WMFP). The flexural strength is highest of 90.26 Mpa in PLA blended with 5% WSFP and then decreased with increase in filler content. PLA blended with WSFP and WMFP shows that increase in water absorption from 0.221 to 0.916 % and addition of WMFP caused water absorption up to 0.428 % which is less compared to WSFP.