Vinyl Ester Resins modified with Perfluoropolyethers

Hydroxy-terminated Perfluoropolyether (PFPE) was modified by copolymerisation with caprolactone or by addition of carboxylic or methacrylic terminal groups to increase the miscibility towards Vinyl Ester Resins (VERs). Fluorinated oligomers were employed as additives for a commercial VER. Depending on both molecular structure and curing conditions, different morphologies were obtained, which in turn influence the final properties of the cured resin. Generally, a significant increase in toughness was observed as is indicated by the stress intensity factor. A marked decrease in water diffusion coefficient was obtained, thanks to the hydrophobic character of PFPE.