Abstract

Results of EIS investigation, outdoor exposure and accelerated testing for polyurethane and the normal temperature-cured fluoropolymer top coatings are presented. Both systems show very high durability in tropical environment. It was demonstrated that fluoropolymer coating is extremely superior to the other systems in weatherability. Its gloss retention is over 60% after 3 years of testing, meanwhile this value is only 20 - 40% for polyurethane couting. Similar conclusions are obtained from data of roughness and 3D profiles of couting surface. Values of fluoropolymer coating resistance Rc and capacitance C, calculated from Nyquist plots, unremarkably changed before and after 4 years of outdoor testing.