Fiber reinforced polymer composites sustainability under prolonged exposure to hot seawater: Experimental and prediction study

•FRP composite was immersed in seawater at different temperatures for duration of 11 years.•Characterization techniques were performed to evaluate the composite degradation.•Failure analysis was conducted to study the failure mode and fiber/matrix bonding.•Prediction model was developed to predict the long-term durability of the composites. This paper presents long-term experimental investigation of E-glass/epoxy and E-glass/polyurethane composites durability exposed to seawater at different temperatures. The thermoset composite samples were exposed to seawater of different temperatures for a prolonged exposure of 11 years. The mechanical properties were evaluated to assess the sustainability of the composites. The failure analysis was conducted to investigate the bonding of fiber/matrix interface. The prolong immersion in seawater results plasticization and swelling in the composite material which accelerate the rate of the fiber/matrix debonding. The long-term behavior of each composite was also predicted for different areas with northern latitudes (30°, 40°, and 50°) using Arrhenius degradation theory.