Effect of Oil Shale Semi-Coke With Different Particle Sizes on Mechanical and Thermal Properties of Low-Density Polyethylene Composites

This study explores the feasibility of utilizing oil shale semi-coke powder as a substitute for heavy calcium carbonate powder in low-density polyethylene (LDPE). Initially, oil shale semi-coke with varying particle sizes is produced by adjusting the ball milling time. Subsequently, LDPE composites with different filler weight fractions are prepared using an internal mixer. The effects of particle size and filler weight fractions on the composites are investigated. The tensile strength of the composites significantly increases with a reduction in the particle size of the oil shale semi-coke and also increases with an increasing filler weight fraction. Based on the analysis of interface interaction parameters and fracture morphology, it is found that the oil shale semi-coke with a ball milling time of 40 min exhibits the best particle dispersion. Thermogravimetric analyses demonstrate that the composites made with oil shale semi-coke have better hot-air stability. Notably, the composites filled with a 29.70% weight fraction of oil shale semi-coke and a ball milling time of 40 min achieve the highest crystallinity and the smallest grain size, aligning with the observed mechanical properties.