A Multifunctinal Coupling Layer for an Advacned Coating System

The U.S. Air Force has identified a need for advanced protective coating systems for its aging aircraft. Durable (30+years) chromate-free coatings are needed to extend the retirement dates of the aging aircraft. A chromate-free coating is needed to avoid the costs of handling of chromate containing hazardous wastes. Unfortunately, in a recent study of chromate-free conversion coatings, all the tested coatings failed to meet the necessary coating requirements (i.e. MilC-81706 Class 1A). According to a Blue Ribbon Advisory Panel assembled by the U.S. Air Force, current coating materials are not likely to meet provide the required 30+ year chromate-free coating.In Phase I we will develop a chromate-free coupling layer for aluminum substrates that will form the first layer of an integrated chromate-free 30+ year protective coating system. We will prepare a multifunctional coupling layer that provides strong covalent bonds between the aluminum alloys and the epoxy primer and in addition also provides excellent corrosion resistance. The phase I efforts will provide basis for a Phase II project where an integrated advanced coating system will be developed.