Composites come clean

New science and processes are applied to next-generation materials.

The introduction of new composite materials for aerospace applications is relatively rare due to the decade or longer it typically takes to develop, qualify, and certify a material. Nevertheless, there is a strong desire within the industry to do just that, particularly as a way to eliminate toxic substances that exist in many composites.

The U.S. Air Force, for example, has spent more than a decade looking for a new composite material that could replace the widely used polymer PMR-15 because it is prepared with a monomer called methyl-enedianiline that is a known carcinogen. The USAF has spent so much time working on a replacement for PMR-15, which NASA developed in the 1970s, because it is one of the few composite materials that can be fashioned into engine components that operate at temperatures as high as 500°F.