Development of high-densitypolyethylene-matrix composites reinforced with silica and kaolin

The mechanical properties of high-density polyethylene (HDPE) composites reinforced with silica and kaolin fillers were studied. Waste yogurt containers were cleaned and processed into polymer matrices and reinforced with varying concentrations of kaolin and silica (0 to 30 wt.%). Fillers were sieved through a mesh of 150 micrometer. Composites were produced using two-ball roll mills and compression moulding technique. Fourier Transform Infrared (FTIR) spectroscopy was used for fillers characterization. FTIR revealed presence of diverse functional groups for the fillers. The fillers' various functional groups, such as hydroxyl (O-H), carbon-carbon (C=C, C?C), carbon-nitrogen (C?N), and carbon-chlorine (C-Cl) groups, were identified by FTIR analysis. Uneven filler dispersion was seen in SEM micrographs; compositions including 6 wt.%, 12 wt.%, and 18 wt.% had better mechanical qualities and a more uniform distribution, but compositions containing 24 wt.% and 30% of filler showed notable agglomeration. Scanning Electron Microscopy (SEM) revealed morphology of the composites. Mechanical testing showed maximum tensile strength of 30.93 MPa and elastic modulus of 297.75 MPa with 12 wt.% filler content. Flexural strength peaked at 77.81 MPa for 18 wt.% filler loading. The maximum hardness value of 63.10Hv was recorded for 24 wt.% filler. Elongation at break and Impact strength gradually decreased with increasing filler content. SEM showed unequal distribution of filler within the HDPE matrix. 6 wt.%, 12 wt.% and 18 wt.% fillers reinforcement produced uniformly dispersed composites with improved properties. 24 wt.% and 30 wt.% filler composites showed better hardness values. Multiple Linear Regression was more accurate in predicting the impact strengths of the examined composites in comparison with predictions by the Artificial Neural Network (ANN). At 12 wt.% filler content, tensile strength increased 17.5% to 30.93 MPa, while flexural strength peaked at 77.81 MPa (an 11.7% improvement) at 18 wt.% loading. With an increase in filler content, however, impact strength dropped dramatically from 0.273 to 0.159 J/mm2, suggesting lower toughness. Filler agglomeration at greater concentrations was discovered by SEM analysis, which accounted for the strength decrease. These composites exhibit promise for uses such as roof ceilings and floor tiles, where high flexural strength is preferred above impact resistance. This research developed composites with improved mechanical properties produced using High density polyethylene waste yoghurt cans reinforced with silica and kaolin for possible use as floor tiles and roofing ceilings.