Allylnadic‐imides: A new class of heat‐resistant thermosets

Allyl‐bicyclo‐(2,2,1)hept‐5‐en‐dicarboxylic(2,3)imides (allylnadic‐imides) are prepared by heating equivalent amounts of allylnadic anhydride and amines. Mixtures of isomers (1‐allyl‐endo, 6‐allyl‐endo and exo) were obtained, separated by flash chromatography and identified by 1H‐ and 13C‐NMR. A series of novel allylnadic‐imide monomers is described. Upon heating to 250°C oligomers are obtained. Diels—Aider rearrangement and “ene” type addition reactions seem to play a major role in oligomer formation. Bis‐ and tris‐allylnadic‐imides are viscous liquids resins or low melting solids, which are soluble in common solvents. Upon heating to 250°C insoluble, high Tg solids are obtained with good thermooxidative and environmental stability and with reduced burning rate. Cured allylnadic‐imide resins are excellent high temperature insulators and low permittivity dielectrics. Crosslinked copolymers with maleic‐imides and epoxy resins are described. Neat resin and carbon fiber composite properties are reported.