Studies on poly(ester-urea-imide)s containing epoxy segment

Novel flame retardant poly(ester-urea-imide)s were prepared by diels–Alder (DA) polymerization reaction of various bisfuran derivatives (3a–e) containing amide linkages with brominated epoxy resin based bismaleimide (4). The so-called DA reaction was carried out by refluxing the mixture of both 3a–e and 4 monomers in THF solvent. The resultant DA adduct was formed which was treated with acetic anhydride at 135 °C. The final products were in aromatized form and designated as poly(ester-urea-imide)s (PEUIs, 6a–e). These polymers were characterized by elemental analysis, number average molecular weight and thermogravimetric analysis. The glass and carbon fiber reinforced composites of such PEUIs were fabricated by ‘in situ’ polymerization process.