Preparation and Characterization of Polyurethane Composite Coatings Reinforced With Carbon Waste

ABSTRACT Given the industrial interest in enhancing materials' mechanical and textural properties, this research focuses on preparing a composite polyurethane (PU) resin coating on ceramic substrates using the cold spray coating technique. The coating was reinforced with 50 μm waste carbon (WC) powder particles from heavy oil cracking, incorporating four different percentages of WC powder (4, 6, 8, and 12 wt%). The cold spray coating was applied at an air pressure of 0.9 MPa and a temperature of 37°C for 20 min, with a standing distance of 40 mm, followed by drying at room temperature for 24 h. XRD, Raman spectroscopy, FESEM/EDS, DSC, apparent porosity, and mechanical properties were analyzed to study the composite coating's structure and morphology. The results demonstrated a significant improvement in mechanical properties, with increased hardness and compressive strength in the (PU/WC) composite coating compared to the pure polymer/substrate. FESEM/EDS images show higher concentrations; clusters of carbon particles within the coating film are formed, resulting in a higher weight percentage of C in EDS analysis, 71.3 and 73.5 wt%, respectively, which means the dense composite coating had a compact structure and improved apparent porosity when the surface is homogenously incorporated with WC at (12% and 16%) about range (0.044%), with an average coating thickness of 1.29 μm and crystal sizes in the order of 2–6 nm by application of the Debye–Scherrer formula. The DSC analysis of the thermoplastic PU revealed a glass‐transition temperature and integral heat energy range of 90.5°C–165°C during heating and cooling processes.