Low-Permeability Coating for Nitrile Rubber

This research will develop a coating for the nylon/NBR fly-through cover (FTC) to reduce water permeation into the missile tube. The point-to-point variability of permeation of our novel coating will be reduced compared to the MTM coating. The currently variable permeation of water compromises the mechanical integrity of the sea-wetted FTC by softening localized regions of the FTC. We will design a tape or film that will be adhered to the surface of the fly-through cover before compression molding. The tape or film will be designed to withstand at least 160 inflation/deflation cycles. We will investigate elastomeric layers and low permeability plastic films bonded inside elastomeric layers. We will investigate two commercially available elastomers as elastomeric permeation barriers. We will prepare compounds with and without platy nanofillers. We will then take the best elastomer compounds and make thermoplastic vulcanizates (TPVs) based on these elastomers in combination with low permeability plastics. Such coatings will be tested for mechanical and permeability properties. Lastly, multilayer structures comprised of the elastomeric compound or compounds, sandwiched with a highly permeation-resistant plastic film layer will be prepared and evaluated. Plastics with permeability from 20-500 times lower than the elastomeric barrier layers will be investigated.