Self-repairing polymer networks for high-performance coatings : final report on Project F12-AR12

Abstract

This project demonstrated the capabilities of a self-repairing additive in a polyurethane topcoat (MIL-PRF-85285 Type II, Class H) applied to the exterior hangar doors in the severely corrosive environment at Corpus Christi Army Depot, Texas. Many conventional coatings when scratched or abraded, may develop corrosion that can lead to rapid deterioration of the substrate steel. The demonstrated self-repairing coating system was also applied to test panels exposed to atmospheric weathering and salt fog testing for 2,000 hours. While the self-repairing coating showed promise on the test panel exposure tests, the system was not able to protect the steel hangar doors due to the excessive mechanical impacts and stresses they are subjected to during daily operations. Department of Defense implementation of the demonstrated self-repairing coating is not currently recommended for use on infrastructure. Further evaluation would be needed to match the self-healing capabilities of the demonstrated coating with lighter-duty steel infrastructure components not subjected to the degree of impact and abrasion as the subject hangar doors. Because the self-repairing coating system did not perform any better than the conventional control coating in this project, the return on investment was zero.

Demonstration of a standard steel coating system modified with a vapor-phase corrosion inhibitor : final report on Project F12-AR14

“…The hangar doors coated in this project are subjected to frequent heavy impacts and abrasion during normal site operations. Also, performing this work on CCAD hangar doors leveraged efforts on a concurrent CPC coating demonstration that used the same type of hangar doors (Divan, Lampo, and Clark 2018). • One hangar door leaf to which the surface was abrasive blasted to a near-white condition following SSPC SP-10 requirements.…”

“…For demonstration purposes, however, the outside of the panels in the lower portion of 5 of the 10 door leaves on the east side (leaves 2, 3, 4, 5, and 9) were prepared and painted with VCI-modified MIL-DTL-24441/20 Formula 150 Type III. At the same time, as part of another demonstration, a self-repairing coating system was applied to panels on door leaves 6, 7, and 8 (Divan, Lampo, and Clark 2018). Panel areas on door leaves 1 and 10 were painted with the control coating system, with door leaf 1 panels prepared to the SSPC SP-10 near-white metal condition and door leaf 10 panels prepared to brush-cleaned SSPC SP-7 condition.…”