Surface properties of alicyclic epoxy coatings modified with reactive copolymer containing fluorinated side chains

An alicyclic epoxy resin was modified with a copolymer having both a perfluoroalkyl side chain and a cyclohexenoxide-terminated side chain. The copolymer had a good solubility in the epoxy matrix during the reaction of the alicyclic epoxy groups on the terminal end of the side chains. Thus, the cured epoxy resin had a homogeneous phase structure and was a colorless material with excellent transparency. The fluorinated side chains were highly self-segregated in the air-side surface (thickness: less than 8 nm) to minimize the interfacial free energy between the air and cured epoxy resin. The surface of the epoxy coatings had a significantly low surface free energy (ca. 20 mJ/m2) and revealed both high hydro- and oleo-phobicities. In addition, the surface had a gradient in the refractive index due to the self-stratification of the C–F bond that has a low polarizability.