Description: NASA future applications require non- incremental advances in high temperature materials. Specifically, advanced future propulsion systems require significant improvement in the upper temperature operating limit of composite materials. Carbon-carbon (C-C) composites exhibit unique properties on increasing strength with temperature but suffer from oxidation at temperatures above 550 C. Over the years significant efforts in the oxidation protection of C-C composites included internal inhibition, external coatings and sealants. The reliability of such oxidation protection system is greatly limited by the intrinsic risk of coating spallation. On the other hand the internal inhibition by itself is incapable of providing sufficient substrate protection at high temperatures without the external coatings. Phase I results provided initial paradigm shift into the feasibility of internal oxidation protection system for 3500 F to 4200 F applications. This Phase II builds on very encouraging and insightful Phase I results and provides for a comprehensive, unique molecular level inhibition of the fiber, intrabundle matrix and interbundle matrix. System chemistry will be optimized to offer NASA a plethora of opportunities in such demanding applications as extension nozzles and combustors offering max temp operation up to 4,200 F with the material system chemistry and molecular inhibition design enabling the composite based parts to experience very large temperature gradients and providing effective oxidation protection of the substrate. In short, the uniqueness of this molecular inhibition system, based on Allcomp’s provisional patent, eliminates the need for external coatings and sealants. By the elimination of the external coatings the huge coating spallation reliability problem will be solved offering a paradigm shift applicable not only to NASA propulsion applications but the plethora of other NASA applications, military, and commercial applications.

Benefits: An inherently oxidation resistant molecular-inhibited C-C composites without the need of external coating protection capable for operating at temperature up to 4200 F can be easily scaled up at low cost for large extension nozzles, high temperature integrated combustor / throat/ exit cone, and advanced heat shields for NASA’s launch vehicles and re-entry vehicles. Examples are NASA Space Launch System and Robotic Lunar Vehicles - Lunar Orbital Platform Gateway to Lunar Surface.

Advanced oxidation resistant C-C can be used in in the propulsion path of advanced missiles systems and for the hot structure of the hypersonic vehicles. In the commercial space market, light weigh, low cost, and scaleable oxidation resistant C-C can also be in the propulsion path of their launch vehicles.