Study of Moisture Diffusion and Cure behavior of Vinyl Ester Resin / Organoclay Nanocomposites

Vinyl ester resin (VER) is amongst the most widely used thermoset polymers in composite industries due to its attractive features such as exceptional chemical resistance, and mechanical properties. The application of nanoparticles such as organoclay has led to developing VER nanocomposites with superior moisture diffusion properties. In the present work, rheometry and water diffusivity experiments were conducted on VER nanocomposites with various organoclay contents (0-5 wt%). The most interesting point regarding the effect of organoclay on the cure behavior of VER systems as it was revealed by rheometry was the chemisorption and physisorption of the reacting monomers and initiator on the organoclay platelets surface which is appeared to be responsible for the higher state of cure. Results indicated that the higher is the cure state, the lower is the equilibrium moisture content. Such phenomenon suggested that the incorporation of the nanoclay could build a perfect network which reduced the water uptake.