Moisture Vapor-Gas Barrier Coatings for Carbon-Epoxy Composites

AZ Technology proposes to design and test an innovative polymer coating system and demonstrate prototype production of a moisture/gas barrier coating to effectively eliminate composite sabot moisture related expansion. The Army has identified a need to reduce expansion of epoxy composite materials used in experimental artillery ammunition sabots. We propose to use our expertise in coating design, experience with application of halogenated polymer systems, and our commercially available composite primer coatings to develop a fully functional composite moisture barrier coating for the Army. Several polymer materials, polyvinylidene chloride copolymers and polytetrafluoroethylene, are proposed as primary candidates. This coating will. be low temperature cured, approximately 1 mil thick, compatible with propellants and depleted uranium, -46 C to 63 C service temperature and easily applied in ammunitions production facilities via high volume low pressure spray technology. Moisture/gas barrier coating development will include defining application procedures that provide for bonding of boot material to the sabot and testing to demonstrate coating suitability. Phase II will investigate improvement coating adhesion and demonstrate application process scale up. Scale up shall include the spray application of the barrier coating(s) onto Government Furnished Material sabots to be used by the Army for full-scale humidity and ballistics testing. BENEFITS: A viable, commercially available moisture barrier coating for composites is beneficial to satellite industry, aircraft industry, and all hardware organizations that use composite materials. Weight reduction is the primary driver for the use of composites. This type of coating will reduce weight of the copposite even further by reduction/elimination of water vapor absorption.