N‐methylolmaleimide–benzene photoadduct: A novel monomer for the synthesis of functionally modified polyimides

A novel polycyclic dihydroxy diimide monomer was synthesized through the photocycloaddition of N‐methylolmaleimide to benzene and the reaction of maleimide–benzene photoadduct with formaldehyde. The monomer, which evolved formaldehyde at about 165 °C, was subsequently used to prepare low molecular weight polyamineimides and polyurethaneimides. Soluble polyamineimides, prepared with three different aromatic diamine monomers, exhibited initial decomposition temperatures between 277 and 329 °C and glass‐transition temperatures between 180 and 219 °C. An aliphatic polyamineimide prepared from 1,6‐hexanediamine was insoluble and had glass‐transition and initial decomposition temperatures of 225 °C and 294 °C, respectively, with prior loss of formaldehyde from end groups. Polyurethaneimides prepared with two aromatic diisocyanates showed loss of formaldehyde in the approximate range of 160–169 °C followed by loss of CO₂ and glass‐transition temperatures of 219 and 233 °C. Attempts to prepare polyamideimides resulted in oligomers with a low nitrogen content. Attempts to prepare polyesterimides were unsuccessful. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2645–2651, 2000