Effect of fixed carbon on the interfacial compatibility of coal gangue/polyethylene composites was investigated using anthracite as a model compound

Abstract

AbstractCoal gangue (CG), a byproduct of coal mining, integrated with polyethylene (PE) offers potential in diverse applications. However, ensuring compatibility between CG and PE remains a challenge due to CG's complex nature. This study explores the influence of fixed carbon, represented by high‐carbon‐content anthracite, on the interface of CG/PE composites. Comprehensive investigations were conducted on physical, mechanical, thermal, microstructural, and chemical aspects. Results revealed that increasing carbon content positively impacted density and hardness while enhancing bending strength and modulus, albeit at a cost of reduced tensile strength. When the C content reached 80%, the hardness and density increased from 50.5 HD and 0.93 g cm−3 to 62.4 HD and 1.18 g cm−3, which were 23.6% and 26.9% higher, respectively. Meanwhile, the bending strength and bending modulus reached 17.2 and 1582.4 MPa, which were 53.6% and 239.1% higher than those of the composites prepared from pure PE (11.2 and 466.7 MPa), respectively. However, the tensile strength decreased by 48.7% from 11.7 to 6.0 MPa. Moderate carbon content positively affected thermal stability, yet higher concentrations posed stability challenges. Microstructural analyses unveiled varied interfacial morphologies, shedding light on carbon's role in enhancing material rigidity and hardness. Surface chemical studies suggested physical entanglement between carbon and PE. Additionally, varying carbon content influenced crystallization, elevating crystallinity and impacting mechanical properties. The findings underscore carbon's potential in reinforcing composite materials. This research provides insights into optimizing CG/PE composites and addressing CG treatment challenges.Highlights Unveiled relationships between fixed carbon and properties in composites. The structure was studied qualitatively and quantitatively by XRD. The anthracite‐C substitution in composite preparation was unraveled.