Furyl-maleimidein situ generated ab-monomers: Synthesis,characterization, and Diels-Alder polymerization

2-Furoyl chloride reacted with the monomaleamic acids 1a-1d derived from a aromatic diamine to yield a new series of maleamic acids 2a–2d . The latter were cyclodehydrated to afford maleimides 3a-3d which behaved as AB-monomers for a Diels-Alder polymerization. In addition, the monomaleamic acid 4 derived from 4-aminophenol reacted with 2-furoyl chloride to yield maleamic acid 5 . It was cyclodehydrated to maleimide 6 which is a novel polymer precursor. The monomers were characterized by IR and ¹H-NMR spectroscopy. Their thermal polymerization was investigated by DTA. Maleamic acids 2a–2d and 5 were cured at 280°C for 22 h to yield polymers which were characterized by TGA and isothermal gravimetric analysis (IGA). They were stable up to 340–376°C and afforded anaerobic char yield of 55–64% at 800°C. © 1992 John Wiley & Sons, Inc.