INTERCROSSLINKED POLYMER NETWORKS BY SIMULTANEOUS CURING OF UNSATURATED POLYESTERS AND BISMALEIMIDE RESINS

The modification of an unsaturated polyester resin by incorporating a second co-reactive monomer as a thermosetting bismalemide is described . The bismaleimide was readily dissolved in the uncured polyester matr ix up to a concentration of about 20 % wt. FTIR isothermal measurement s indicated that the kinetics and the mechanism of the curing process were strongly affected by the presence of the bismaleimide. The result ing inter-crosslinked network showed a gradual enhancement of the elas tic modulus in a wide range of temperatures by increasing the bimaleim ide amount in the system. This enhancement was obtained without alteri ng the intrinsic toughness of the matrix.