"EROSION- AND OXIDATION- RESISTANT PROTECTIVE COATING FOR POLYIMIDE SHEETING"

POLYIMIDE MATERIALS, NOTABLY KAPTON, FIND USE IN THE OUTER COVERINGS OF SPACE VEHICLES FOR PURPOSES SUCH AS THERMAL INSULATION. WHILE EXPOSED TO THE RAM ATOMIC OXYGEN PRESENT IN A LOW-EARTH ORBITAL ENVIRONMENT, THE KAPTON UNDER-GOES A DEGRADATION PROCESS. IT HAS ALREADY BEEN FOUND THAT A COATING OF SILICON OXIDE OR ALUMINUM OXIDE OVER THE KAPTON GREATLY EXTENDS ITS SERVICE LIFE DURING THIS EXPOSURE TO OXYGEN. HOWEVER, THE OXIDE COATINGS ARE BRITTLE AND SUBJECTTO CRACKING. IT IS THE PURPOSE OF THIS RESEARCH TO DEVELOP A COATING WITH THE DESIRABLE PROTECTIVE PROPERTIES OF THE EARLIER FILMS, BUT WHICH ARE ALSO MUCH MORE CRACK-RESISTANT. SECONDARILY, IT WOULD ALSO BE DESIRABLE FOR THIS NEW FILM TO BE UV-OPAQUE, SINCE UV RADIATION ALSO CHEMICALLY DEGRADES KAPTON.