THERMALLY STABLE POLYMERS BASED ON BISMALEIMIDES CONTAINING AMIDE, IMIDE, AND ESTER LINKAGES

Seven new structurally different bismaleimides were synthesized and characterized by infrared and proton nuclear magnetic resonance spectroscopy. The chain of these polymer precursors was extended by incorporating amidized, imidized, and esterified 4-chloroformyl phthalic anhydride. The bismaleimides containing amide and imide linkages were prepared by a simple synthetic route based on the reaction of the monomaleamic acid derived from various aromatic diamines (1 mol) with 4-chloroformyl phthalic anhydride in (0.5 mol) and subsequent cyclodehydration of the intermediate triamic acid. In addition, chain extended bismaleimides were prepared by reacting the monomaleamic acid derived from p-phenylenediamine with several dianhydrides such as p-phenylene (bis(trimellitamide anhydride), p-phenylene bis(trimellitate anhydride), and bis(phenol A bis(trimellitate anhydride). The differential thermal analysis scans of bismaleimides showed exotherms at 221-304°C associated with their polymerization reactions.