Synthesis, characterization and stability of bismaleimides containing ester groups in the backbone

A new series of bismaleimides containing ester groups in the backbone were synthesized from maleimido benzoic acid via its acid chloride with 4,4'-(hexa-fluoroisopropilidene)diphenol, 2,7-dihydroxynaphtalin, 1,3-dihydroxy-benzene and 4-hydroxyphenyl sulfone by simple condensation reaction. The monomers are characterized by IR, H-1-NMR and elemental analysis. DSC studies of these bismaleimides indicated a curing exotherm in the temperature range 260-306 degrees C with polymerization heat 92.9-139.6 J/g. Thermogravimetric analysis of the monomers showed high thermal stability for all bismaleimides.