SYNTHESIS AND CHARACTERIZATION OF A NEW BISMALEIMIDE RESIN MATRIX FOR COMPOSITES

A bismaleimide monomer containing etherimide linkages was synthesized from 3-nitrophthalic anhydride, diamino diphenyl ether and bisphenol-A by the principle of activated nucleophilic displacement reaction and finally reacting the produced diamine with maleic anhydride. The monomer was characterized by elemental analysis, IR and NMR spectroscopy. It is highly soluble in low boiling solvents such as chloroform, tetrahydrofuran, etc. It forms a cross-linked polymer on heating to 200-degrees-C and higher. The cured product is completely insoluble in usual solvents including conc. H2SO4. The thermal behaviour of the bismaleimide was studied by TGA, DTA and isothermal aging. The polymer is stable up to 300-degrees-C. Laminates prepared with this resin and carbon fiber are almost void-free and possess good mechanical and thermal properties. These properties are compared with earlier reported bismaleimide imide prepolymer based composite.