Effect of Al${}_2{O}_3$ Nanoparticles on the Mechanical and Physical Properties of Epoxy Composite

The effect of alumina nanoparticles and the dispersion homogeneity on the composite performance, in terms of mechanical and physical properties, has been studied extensively. The effect of alumina nanoparticles weight percentage (0.25–0.5–0.75–1 wt%) and particle size of 60 nm mixed with commercial epoxy resin (Kemapoxy 150) are used in this investigation. Bending, hardness, tension, erosion, water absorption, and TGA tests are studied. Experimental results indicate improvement in the mechanical behavior with 0.25 wt% particles for both bending strength and wear resistance by 7 and 67% relative to pure epoxy. Water absorption depends mainly on particle distribution, and TGA testing slightly increases with the increase in particles dosage. The tested samples were studied using environmental scanning electron microscopy. Good distribution and dispersion of nanoparticles in the epoxy matrix lead to reducing the mobility of the epoxy chains due to the formation of high immobile nano-layers around the alumina nanoparticles. Thus, creating hydrogen bonding between chains and particles. Consequently, increased constraints between particles/polymer chains and polymer chains themselves are found leading chains to bear extra forces. Fracture strength decreases due to nanoparticles agglomerations causing an increase in the space distance (free volume space) between epoxy chains. This study suggests possible applications of the tested coating due to improved mechanical and physical properties upon nanoparticles addition.