Low-Permeability Coating for Nitrile Rubber

The TOMAHAWK Capsule Launching System (CLS) is being leveraged for integration of the littoral Warfare Weapon (LWW) on SSGN and SSN 688I/Virginia Class Vertical Launch System capable platforms. The CLS includes a nylon fabric reinforced nitrile rubber fly-through cover. During stowage of the capsule, the fly-through cover can be exposed to seawater. The fly-through cover must seal the capsule interior, which houses a missile, from the external environment. Since the nitrile rubber is permeable, and the humidity inside the capsule must be maintained below a certain threshold, a Mylar®-tin foil-Mylar® low permeability barrier is installed over the nitrile rubber cover. This barrier is expensive, easily damaged, and presents potential debris concerns after missile launch. METSS has identified several coatings that adhere strongly to nitrile rubber and provides the required level of protection. The Phase I results demonstrate the technical feasibility of protecting the nitrile rubber fly-through cover with an organic barrier coating. The coatings provide sufficient protection to the nitrile rubber that no evidence of deterioration of the rubber was observed after accelerated aging in seawater at elevated temperatures, in comparison to unprotected rubber samples, which experienced noticeable degradation in properties. The accelerated aging data provides a good estimate that the projected service life requirements can be met through application of the coatings developed in this program. During Phase II METSS intends to develop these coatings to the point where they exhibit demonstrable long-term protection of the nitrile rubber fly-through cover.