A new class of polymeric materials was developed with resistance to heat, dielectric breakdown, and oxidation at high temperatures. For applications that demand high temperature resistance coupled with greater strength, these polymers can be easily transformed into ceramics with extreme thermal and oxidative stability.
The new polymeric materials — made from resins derived from carboranes and either vinyl or acetylene siloxanes — can resist temperatures up to 510 °C (950 °F) in air, and are highly resistant to chemical attack. They can be molded, injected, or coated, and are also highly adhesive. The acetylenic variety is thermally cured at 200 °C, whereas the vinylic type cures at room temperature. Once cured, the hardness and strength of the materials can be substantially increased by thermally converting them to a novel lightweight ceramic that can withstand temperature in air of at least 1500 °C. While the network polymers possess all of the inherent siloxane characteristics, they are highly insulating in nature, with exceptional high-temperature dielectric stability under high voltages.
Organic unsaturated-containing poly (carboranylenesiloxanes) materials are viscous liquids at room temperature and are easily processed into shaped configurations. The opportunity to convert the materials into network polymers at room temperature or at elevated temperatures provides a broad range of applications for these materials. Structural characteristics can be controlled easily by diluting the crosslinking density in the materials. Structural components can be readily fabricated by cost-effective methods such as resin transfer molding, resin infusion molding, and filament winding.
Applications for the materials exist in aerospace engine applications, insulative coatings for high-performance organic and metal fibers, high-temperature adhesives, and high-temperature dielectrics for electronic applications.