Effect of irregular shaped nanoalumina on the enhancement of mechanical properties of epoxy resin nanocomposites using DDM as hardener

This article presents experimental results on the mechanical properties of epoxy (EP) resin nanocomposites (EPNCs) reinforced with alumina nanoparticles. The nanoparticles consisted on alpha alumina with irregular shapes (100 nm maximum size) pretreated with a silane agent (3-Aminopropyl triethoxysilane, APTES). During the preparation process, silane-functionalized alumina nanoparticles, are covalently connected to the epoxy matrix by the reaction of the amine groups with the epoxy groups, creating stronger interfacial interactions between the nanoalumina (the filler) and the EP matrix. At the curing process, the amine groups of the 4,4′-Diaminodiphenylmethane (DDM (the hardener)) will react with the epoxy groups, creating/reinforcing the network interlock at the polymeric matrix. The weight fractions of alumina nanoparticles were as follows: 1, 3 and 5 wt.%. After testing, and when compared with the neat EP, the EPNCs containing 1 wt.% of alumina nanoparticles showed the maximum improvement on the mechanical properties. Better dispersion of nanoalumina particles was achieved for 1 wt.%.