The Department of Defense (DoD) relies heavily on hexavalent chromium (Cr[VI]) as a corrosion-inhibiting additive and adhesion promoter in military primer formulations that are currently found on aluminum and steel alloys. Incorporating a corrosion-inhibiting compound such as derivatives of 2,5-dimercapto-1,3,4-thiadiazole (DMcT), which have been shown to mimic the corrosion-inhibiting properties of Cr(VI), will provide DoD an attractive Cr(VI)-free alternative. The objective of this project is to demonstrate a new primer formulation that can be incorporated into either a Cr(VI)-free epoxy or a conductive polymer (CP) formulation.

This new primer formulation developed by Crosslink in cooperation with the Naval Air Systems Command (NAVAIR) can be incorporated into either a Cr(VI)-free epoxy or in a CP formulation. The Navy, Air Force, and Army will test both formulations, along with Cr(VI) controls, for performance. Each Service will test the Crosslink Cr(VI)-free primer formulations on substrates using full military coatings under controlled laboratory conditions. The best performing military coating will be down selected and field tested on noncritical military equipment.

A completely Cr(VI)-free military coating will result in a significant reduction in the costs of disposing of hazardous Cr(VI) waste, improved worker safety, compliance with existing and future environmental regulations, and military equipment sustainability in support of mission readiness. (Anticipated Project Completion - 2013)