UV-cured epoxy coatings modified with perfluoropolyether-based materials

Hydroxy terminated PFPE were chain extended with short PCL segments in order to enhance the compatibility towards the epoxy resin. The obtained PFPE-PCL block copolymers were used as additives to modify toughness of a UV curable bisphenol-A-based epoxy coating. A certain degree of phase separation was achieved during UV curing. The morphology of the obtained cured materials depends on the polycaprolactone PCL length. The perfluoropolyether PFPE additive, without any PCL segment (additive TX), clearly showed a biphasic morphology with separated domains within 50-100 mu m. By increasing the PCL segment it was not identified any second distinct phase. It was shown that the addition of TX additive can generate a strong phase separation and this allowed to achieve an improvement of the toughness properties of the cured samples without affecting the thermo-mechanical properties. (C) 2010 Elsevier B.V. All rights reserved.