Synthesis and characterization of cyano‐substituted maleamic acids and maleimides and their polymerization to thermally stable laminating resins

Abstract

AbstractA novel class of cyano‐substituted maleimides were prepared and polymerized. Particularly, 4‐aminobenzonitrile reacted with maleic or nadic anhydride to yield the amic acid, which was then cyclodehydrated to the corresponding maleimide or nadimide. In addition, the monomaleamic acids prepared from an aromatic diamine reacted with 4‐cyanobenzaldehyde to afford maleamic acids that were cyclodehydrated to maleimides. All maleimides and nadimide as well as their intermediate amic acids were characterized by IR and 1H‐NMR spectroscopy. The curing behavior of polymer precursors was investigated by DTA. Upon curing at 240°C for 15 h, network polymers were obtained both by cross‐linking through the maleimido olefinic bonds and the trimerization reaction of the cyano groups. They were stable up to 330–310°C in N2 or air and afforded anaerobic char yield of 60–40% at 800°C. © 1993 John Wiley & Sons, Inc.