Low-Permeability Coating for Nitrile Rubber Navy SBIR FY2008.1 Sol No.: Navy SBIR FY2008.1 Topic No.: N08-042 Topic Title: Low-Permeability Coating for Nitrile Rubber Proposal No.: N081-042-0685 Firm: Systems and Materials Research Corporation 1300 West Koenig Lane Suite 230 Austin, Texas 78756 Contact: Alan Bray Phone: (512) 535-7791 Web Site: systemsandmaterials.com Abstract: Researchers have tried for years to make low water vapor transmission rate (WVTR) elastomers without success. Developing low WVTR coatings for the Tomahawk missile fly-through nitrile covers requires a breakthrough technology in barrier materials. A nanocomposite elastomer is proposed that exploits tortuous path and constrained polymer (TP/CP) effects that accrue with high aspect ratio clays such as vermiculite. A "brick wall" like structure is formed that resists water vapor permeation. Permeation improvements to factors of 100-500 compared to the pure polymer are possible with well formed nanocomposites. The result is a barrier material as impermeable as any known polymer - but still elastomeric. Candidate resin/clay combinations will form nanocomposite coatings to be tested for WVTR and elastic properties. WVTRs are projected in the range of 10e-3 gm/100 in.e-2/day/mil, which - based on a ROM model of missile tube relative humidity - is enough for a 33 year barrier life. Physical properties will be tested for each barrier/cover combination before and after accelerated aging exposures. In Phase I Option an OEM elastomer lamination company will help develop a manufacturing strategy and produce pre-prototype fly-through cover bi-laminates for proof testing. Raw material and processing costs are low, netting at least a 40% part cost reduction. Benefits: Elastomer use in the Navy is ubiquitous - there are literally hundreds of elastomer encapsulated parts on naval systems, and many of these would function better if they were more impermeable to water vapor. Examples include inflatable rafts, underwater acoustic transducer boots, sonar domes, and towed arrays. Commercial prospects are just as bright - sprayable impermeable elastomeric coatings could be a huge market in home and commercial vapor barriers. Since the raw materials are commodity elastomers and clay - both very inexpensive products (e.g. clays for this application would cost under 25 cents a pound AFTER processing). Bi-laminate processing equipment is already in place at hundreds of OEMs, and the cost of the final product will be much less per square foot that any available and comparable impermeable materials. The market for impermeable elastomers could reach hundreds of thousands of pounds in the first few years after introduction, reducing the cost to Navy and civilian users proportionately. Return