Experimental study on the thermal and mechanical properties of multi-walled carbon nanotube-reinforced epoxy

In this study, multi-walled carbon nanotubes (CNTs) were infused into Epon 862 epoxy through a high intensity ultrasonic liquid processor and then mixed with EpiCure curing agent W using a high-speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. Dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and flexural tests were performed on unfilled, 0.1, 0.2, 0.3, and 0.4 wt% CNT-filled epoxy to identify the loading effect on the thermal and mechanical properties of composites. DMA studies revealed that filling the carbon nanotube into epoxy can produce a 90% enhancement in storage modulus and a 22 °C increase in Tg. However, due to the lower crosslink density of the nanophased systems, a 6 °C decrease in decomposition temperature was observed in the 0.4 wt% CNT/epoxy in the TGA test. The flexural results showed that modulus increased with higher CNT loading percentages and the 0.3 wt% CNT-infusion system showed the maximum strength enhancement. Based on the experimentʹs results, a nonlinear constitutive equation was established for neat and nanophased epoxy.