Effect of In-Service Temperature on the Flexural and Creep Behaviour of Carbon Nanofiber Embedded Epoxy Nanocomposite

Abstract

In the present scenario, polymeric composites are becoming more popular for electro-magnetic (EM) shielding applications, where internal heat generation in the component is a general phenomenon. Reinforcement of carbon nanofiber (CNF) in epoxy based polymer has drawn significant attention in this regard to enhance the shielding effectiveness. But, at the same time understanding of the mechanical performance of these materials at above ambient temperature environment is equally important to prevent any unwanted damage. Current investigation has been focused to evaluate the mechanical, thermo-mechanical and creep performance of 0.5 wt.% CNF embedded epoxy (CNF/EP) nanocomposite at elevated temperature environments. The nanocomposite exhibits 18% higher strength and 12% higher modulus over neat epoxy, when testing was done at room temperature. However, the rate of strength deterioration was found to be more rapid in case of the nanocomposite than neat epoxy, as temperature rises. Eventually at 90 °C, the nanocomposite shows a negative reinforcement effect due to extensive interfacial debonding. This fact has also been supported by the thermo-mechanical behaviour of both materials, which suggests a higher reinforcement efficiency of the nanocomposite in the early glassy state. Ambient temperature (30 °C) creep test suggests a significant resistance towards creep deformation of the nanocomposite over neat epoxy. However, beyond a critical temperature, the nanocomposite yields a relatively poor creep performance, suggesting the need of suitable interfacial engineering to make these materials more durable under elevated temperature environments.