Funct. Mater. 2025; 32 (3): 380-385.
Investigation of the mechanical characteristics of composites based on CFA and rLDPE
1Department of Mechanical Engineering, Faculty of Engineering, Halu Oleo University, 93232 Kendari, Indonesia
2Department of Civil Engineering, Faculty of Engineering, Halu Oleo University, 93232 Kendari, Indonesia
3Department of Management, Faculty of Business and Economics, Halu Oleo University, 93232 Kendari, Indonesia
The effect of coal fly ash (CFA) as a filler in recycled low-density polyethylene (rLDPE) matrix composites on the compressive strength, flexural strength and flexural modulus of this material was investigated. The composites were prepared by blending CFA and rLDPE at levels of 20 wt%, 30 wt% and 40 wt% CFA with 80 wt%, 70 wt% and 60 wt% rLDPE. Mixing was carried out at 160 °C until the rLDPE melted, then CFA was added and mixed until homogeneous. The mixture was then poured into a mold and subjected to direct molding. Compressive strength tests were performed according to ASTM D695 and flexural strength tests according to ASTM D790-03. SEM analysis was used to characterize the microstructure of the composite. The results showed that the composite with 20 wt% CFA and 80 wt% rLDPE provided the highest compressive and flexural strength of 9.60 MPa and 16 MPa, while higher proportion of CFA reduced the compressive strength. SEM analysis shows that good distribution of CFA in rLDPE matrix improves the mechanical properties of the composite.