In mid 2008, ATC began a project funded by the state of Ohio, to commercialize coatings that would allow polymer matrix composite materials to operate under extreme conditions. The project is part of a large consortium lead by the University of Dayton Research Institute (UDRI). ATC�s role in the consortium is to develop and produce coating materials to be used as integrated and traditional coatings for polyimide and epoxy based systems.

An integrated coating differs from a traditional coating in that the coating is not a separate entity; instead it is integrated into the sub-structure. The major thrust of our work is to develop hybrid integrated coatings, where the coating material contains some amount of the base material. This method should enhance adhesion, reduce CTE mismatch problems and possibly reduce parasitic weight. That is, the coating would also contribute to the structural component.

The earliest work performed by ATC was on ultra high molecular weight polyethylene (UHMWPE). In this case, an integrated hybrid coating was co-molded with UHMWPE and tested mechanically and thermally. Initially, it was thought that the coating would be too brittle compared to the UHMWPE. However, during 3 point bend testing, where the coating was placed in tension and compression, there was no cracking or delamination of the coating.

Thermal testing of the coating was performed using an oxy-acetylene torch which had a heat output of ~ 600 W/cm². Two tests with the torch impinging on the coated surface of a 4 in. x 4 in. sample were performed for 15 s each. The video below shows the 2nd of the 15 second tests. After both tests the sample self extinguished and there was little damage to the coating and no damage to the underlying polyethylene.

The micrograph below shows a cross-section of the UHMWPE coating after testing. Notice the small amount of intumescence at the surface and the lack of a "sharp" 2-dimensional interface between coating and substrate.

ATC is currently working on developing this type of coating for epoxy and polyimide based systems for improved thermo-oxidative, errosion and abrasion resistance.