Objective: The objective of this project is to demonstrate an effective, environmentally benign, repairable coating system using electroactive polymers (EAP) as a replacement for chromated conversion coatings (CCC). Performance will be validated with currently used non-chromated primers on aluminum, titanium, and composites, as well as on steel. Technology Description: The coating system to be demonstrated and validated involves the use of an EAP (a poly(phenylene vinylene)) as the pretreatment material to replace hexavalent chromium on aluminum alloys. Numerous reports have shown that EAPs coated on various substrates and exposed to corrosive environments can inhibit and retard corrosion. These studies have laid the foundation for the current work using EAPs by Naval Air Systems Command, Weapons Division (NAVAIR-WD). Recent work has demonstrated that poly(phenylene vinylene), specifically BAM-PPV, can perform as well as current CCC in a coating system in neutral salt fog experiments. Similar to chrome, the actual mechanism of corrosion protection from EAPs is still being studied. Some theories involve metal passivation, changes in the metal oxidation potential, or serving as an efficient barrier. To demonstrate and validate the potential usefulness of BAM-PPV as a conversion coating or pretreatment in military coating systems, several demonstrations will be performed by NAVAIR, Air Force, and the Army. These demonstrations will address issues of application, removal, corrosion performance, repairability, and compatibility with substrate materials and primers. Expected Benefits: An environmentally benign, repairable EAP-based coating system as a replacement for hexavalent chromium pretreatments will lead to significant life cycle cost savings as well as compliance with existing and future environmental regulations. In addition, performance of non-chromated coating systems will be enhanced. (Anticipated Project Completion - 2009) Principal Investigator:
Dr. Peter Zarras
Naval Air Systems Command
Code 4T4220D
1900 North Knox Road (Stop 6303)
1 Administration Circle
China Lake, CA 93555-6106
Telephone: (760) 939-1396
Fax: (760) 939-1617
E-mail: peter.zarras@navy.mil
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