Abstract: Radomes having increased transparency and reduced reflectivity and refractivity to radar waves may be prepared or repaired utilizing heat-curable resin-containing structural materials in which the heat-curable resin contains greater than about 70 weight percent of cyanate functional monomers. The structural materials take the form of matrix resin impregnated prepegs and composites, film adhesives, paste adhesives, syntactic foams, and expandable foams, and may be used to prepare numerous useful structural features including honeycomb materials and leading edge radomes containing syntactic foams. The heat-curable resins further facilitate the preparation of low observable structures.

Abstract: The title compounds correspond to the formula ##STR1## and are useful as stabilizers for organic polymers and lubricating oils to counteract the degradative effects of heat, light and air.