Study of the effect of silica nanofillers on the sea-water diffusion barrier property of unsaturated polyester composites

With successful applications in every other field, composites have been used in making boats, offshore structures and various marine structural applications for past few decades, owing to their superior strength-to-weight ratio and performance-to-cost ratio. Usually, marine environment poses serious challenges to the choice of materials due to the presence of corrosive seawater which significantly decreases their life-time. Slowly, nanocomposites are increasingly becoming popular because of nanoscale effects, large interface area and strong interfacial interactions between nanoparticles and polymer. In the present study, Silicon dioxide nanofillers were used as additive in order to enhance the barrier property of composites against water diffusion and hence to prevent it from mechanical degradation. Being one of the most commonly used resin for making composites, unsaturated polyester was chosen for study. Resistance to sea-water diffusion and water absorption rate was studied while varying parameters like ambient temperature and salinity of water. It was observed that the presence of nanoparticles significantly decreases the maximum water uptake and moisture diffusivity in the composite. It was also found that as the salinity of sea-water increases and temperature decreases, degradation due to water absorption decreases.