Next Generation, Polymeric-based Ablative Nanostructured Materials

Nanocomosites using montmorillonite nanoclays dispersed in phenolic resins were shown in Phase I to make significant improvements in standard ablative materials, including erosion rate, mass loss, and heat-soaked bondline temperature. Nanoclay loadings of2% by weight replaced an equal amount of carbon black filler in MX-4926, the standard ablative prepreg for rocket nozzle asemblies. Preliminary results indicate reductions in peak erosion and bondline temperatures over the heat flux range 650 to 1000Btu/ft-s. Phase II will build on this foundation by optimizing for ablation performance through a formulate-and-test strategy. Screening will be done using the SWT Simulated Solid Rocket Motor (SSRM) test facility, and actual small rocket firings conductedby Pratt & Whitney Space Propulsion. Nanocomposite rocket ablative materail (NRAM) formulations will be prepared in small batches for test and selection screening at SWT, then scaled up to prepregs at Cytec Fiberite. Formuations will include varying weightfraction, varying nanocomposites - including nanoclay, POSS, and carbon nanofibers - and modifying three ablative materials currently on the market. The goal for NRAM develpment is a lighter weight, lower cost, better ablative material. Phase I datasupport this claim and the optimization of NRAMs in Phase II is expected to improve noxxle assembly ablative performance considerably. A full scale focket test if sugested as an option to Phase II or a Phase III effort to certify NRAMs for use in theentrance region and exit cone of rocket nozzle assemblies.