Effect of TiC nanoparticles on accelerated weathering of coir fiber filler and basalt fabric reinforced bio/synthetic epoxy hybrid composites: Physicomechanical and thermal characteristics

In the present research, the physical, mechanical, and thermal characteristics of bio and synthetic basalt fabric epoxy composites reinforced with coir microparticles and TiC nanofillers under before and after exposure of accelerated weathering were investigated. All the bio and synthetic epoxy hybrid composites were exposed to humidity, elevated temperature, and ultraviolet radiation. It has been examined that both bio and synthetic epoxy composites exhibited reduced mechanical characteristics after the exposure of accelerated weathering when compared with before exposure. The wettability experiment was performed from the contact angle evaluation method and found that all the fabricated samples before and after the exposure of accelerated weathering have contact angle value lower than 90 degrees that is assigned with the hydrophilic surface characteristics of the laminate. The water absorption capacity showed that all the bio and synthetic epoxy composites reacted for water absorption up to 45 days and then endured constant in both conditions. After the exposure of accelerated weathering, epoxy hybrid composites absorbed more water than before exposure. The chemical modifications possessed on the surface were evaluated from Fourier transform infrared spectra. The intensity of hydroxyl and carbonyl functional groups of bio and synthetic epoxy hybrid composites decreased compared with the original samples, which tends to decrement in tensile, flexural, and impact characteristics of the laminate. The production of more fracture lines on the cross-sectional surface of epoxy hybrid composites has been observed from scanning electron microscope micrographs after the exposure of accelerated weathering. The onset, end set, and glass transition temperature of bio and synthetic epoxy composites in the thermal examination were reduced after the disclosure of accelerated weathering for all fabricated specimens. The reason may be assigned to the weaker bonding between the coir microparticles and TiC nanofillers. The undesirable impact emerged from ultraviolet radiation, elevating the temperature and humidity. The test results showed that the accelerated weathering has negative impact on physicomechanical characteristics of bio/synthetic epoxy hybrid polymer composites. The overall thermal characteristics were not considerably affected with 570 h of the weathering exposure.