Poly(ethylene-co-vinyl acetate)/calcium phosphate nanocomposites: contact angle, diffusion and gas permeability studies

Poly(ethylene-co-vinyl acetate) (EVA) based nanocomposites were prepared by melt mixing in an internal mixer with nanoparticles of calcium phosphate. Contact angle measurements of the composites with water and methylene iodide were measured. Parameters such as total solid surface free energy, work of adhesion, interfacial free energy and spreading coefficient were calculated. The interaction parameter between the polymer and the liquid has been calculated using Girifalco-Good's equation. Water diffusion studies of the composites were done at two different temperatures, 27 A degrees C and 50 A degrees C to know the solvent uptake behaviour. Water diffusion showed remarkable reduction with respect to the filler content. Gas permeability studies with oxygen and nitrogen also showed improvement in barrier properties for the composites.