Characterization of mechanical, thermal, and morphological properties of nano-TiO₂ doped glass fiber/epoxy composites under severe thermal cycling and dynamic loading conditions for aerospace applications

Abstract The exploration is carried out to estimate the properties of glass/epoxy (GE) composites under thermal conditioning environment with and without embedding of TiO 2 nanoparticles in the epoxy matrix. Evaluation of flexural strength and flexural modulus of the GE composites was carried out at different loading rates i.e. at 1, 10, 100, 500, and 1000 mm/min and at different test conditions. The polymer phase was reformed using different concentration (0.1 wt%, 0.3 wt% and 0.5 wt%) of nano-TiO 2 filler. The different sets of specimens were thermally conditioned at a temperature range of + 60 °C for duration of 12 h and same specimens again treated at – 60 °C for 12 h. This thermal shock conditioning was carried out for a period of 30 days. The unconditioned specimens follow an increasing trend in flexural strength with increase in the loading rates. But for conditioned specimens, the flexural strength increases up to 10 mm/min and after further increase in loading rates the strength decreases for all nano-TiO 2 concentration. Maximum strength for flexural tests was obtained for 0.1 wt% nano-TiO 2 embedded GE composites for both conditioned and unconditioned composite specimens. The flexural strength was better in case of thermal conditioned specimen as compared to that of unconditioned specimen. Fractography analysis of failed composite specimens was carried out using scanning electron microscopy (SEM) and glass transition temperature was measured using differential scanning calorimetry (DSC). The developed nano-TiO₂ reinforced GE composites, with enhanced mechanical and thermal steadiness under severe thermal cycling and dynamic loading, are predominantly appropriate for aerospace structural components, UAV housings, radome panels, fairings, and other high-performance lightweight applications.