Low-cost Ramjet Combustor Insulators

Period of Performance: 10/10/2002 - 04/10/2003


Phase 1 SBIR

Recipient Firm

Mississippi Polymer Technologies, Inc.
13233 Webre Road
Bay Saint Louis, MS 39520
Principal Investigator


Mississippi Polymer Technologies, Inc. (MPT), in cooperation with Atlantic Research Corporation, proposes to develop ultra-high performance Parmaxr Self-Reinforcing Polymers (SRPs) for ramjet combustor applications. Parmaxr SRPs, which offer strengths comparable to mild steels and specific strengths comparable to titanium alloys, are thermoplastic polyparaphenylenes with superior ablative properties. This combination of low-cost thermoplastic processing and high char-yield makes Parmaxr SRPs ideal insulators. Parmaxr SRPs provide a rigid char that will withstand the combustor flow field shear forces without degrading the produced energy; offering lighter weight and higher performance (thermal diffusivity, conductivity, and ablative performance) than existing silica-filled silicone rubber materials. Additionally, Parmaxr SRPs will offer enhanced bondability and minimized off-gassing at the case bondline. In fact, because of their great strength, Parmaxr SRPs may offer the capability to fabricate ramjet or integrated rocket/ramjet engines without the use of an insulated steel case. This will provide tremendous system performance increases, including increased range/payload, reduced logistical cost, and potentially reduced lifecycle cost as a result of reduced corrosion concerns. Parmaxr SRPs are able to offer this unparalleled capability because of their unique chemistry - no other material in existence is comparable to these amorphous thermoplastic rigid-rod polyparaphenylenes. Successful completion of Phase I R&D will provide an excellent foundation for replacing heavy glass fiber and high fabrication cost carbon fiber insulation in not only ramjets but also integral rocket/ramjet and pure rocket designs. Parmaxr SRPs will offer the convenience of thermoplastic processing in place of traditional tape-wrapping, fiber placement, and weaving/impregnation fabrication technologies. Parmaxr SRPs are melt processible allowing use of injection molding, compression molding, and extrusion. Parmaxr SRPs with specific gravities in the range of 1.2 will weight less than present insulations offering system performance enhancements as well. Additionally, the results from this Phase I effort will also provide sufficient data to allow placement of Parmaxr SRPs into both DoD and commercial aircraft structures. Parmaxr SRPs do not contain sulfur or nitrogen so in fire situations there are no hydrogen sulfides or cyanides produced. Parmaxr SRPs are also lightweight and strong so these materials are ideally suited for use in manned aircraft or spacecraft.