Chromate-Free Flexible Primer

ABSTRACT: Chromated polysulfide primers provide excellent corrosion protection and the high degree of flexibility required at seams and fasteners. However, hexavalent chromates are known carcinogens and their use is strictly regulated.In addition, polysulfides are highly viscous and the solvents used to reduce viscosity are regulated due to their impact on air quality.An ideal flexible aircraft coating would provide the elongation of a polysulfide primer, corrosion protection without adding chromates, and would have intrinsically low viscosity without high levels of solvents (VOCs).To meet these requirements new innovative materials are required. TDA Research, Inc. has designed a new flexible resin to provide the needed balance of flexibility and chemical resistance in a fast drying, VOC-compliant formula.Furthermore, TDA has developed a class of corrosion inhibitors that can dramatically increase corrosion protection performance through a targeted extended release mechanism.In this SBIR project, TDA will develop a flexible, yet chemically and water resistant primer using a new, proprietary low-viscosity starting material, combined with existing commercially available epoxy and amine compounds, and TDAs chromate-free inhibitors. We will work with a major coating manufacturer to combine our chromate-free inhibitors with the novel flexible resin, and formulate a flexible primer to meet MIL-PRF-32239.; BENEFIT: The VOC compliant, chromate-free flexible coatings are applicable to commercial as well as military aircraft.Further, the non-chrome corrosion inhibitor additives developed in this project can be added to other military and commercial primers and coatings wherever corrosion protection is required.They can be employed to protect metals from corrosion in a wide range of applications, including automotive, aerospace, bridges and building.They will provide effective corrosion protection without the health and environmental hazards of hexavalent chromates and without needing high levels of VOCs.