Influence of α-MnO2 and Curing Temperature on Density and Microhardness of Epoxy Nanocomposites

Abstract

α-MnO2/epoxy nanocomposite shows great potential for structural and tribological applications. The properties of epoxy nanocomposites depended on weight percent (wt.%) loading of reinforcement material and curing temperature. Therefore, the current study examines how neat epoxy’s density and microhardness were affected by the weight percent (0.5, 0.75, and 1.0 wt. %) loading of nano α-MnO2 and curing temperatures (24°C, 50°C, 80°C, 100°C, and 140°C). The samples were created using a procedure called the solution mixing method. Phase and surface morphology of the nanocomposite were analyzed by X-ray diffraction and scanning electron microscopy, respectively. The density of the samples was measured using mass and volume relationship. Density analysis indicated that the density of the nanocomposite increased with increasing wt.% loading of α-MnO2 and decreasing with curing temperature. According to the microhardness study, the nanocomposite samples exhibited lower microhardness with higher wt.% loading of α-MnO2 and an increasing curing temperature. At the indentation load, however, none of the samples developed indentation fractures. The probability plot of the microhardness data at the 95% confidence level showed that the sample’s hardness statistics were unaffected by load and the position of the indentation mark. Analysis of variance results indicated that the wt.% loading of α-MnO2 had a significant effect on the density and microhardness of the nanocomposite, with contributions of 77.7% and 74.75%, respectively, and the effect of curing temperature was small compared to the loading of α-MnO2. The results also indicated that the optimal loading of α-MnO2 in epoxy was 0.5 wt.% and optimal curing temperature at room temperature.