Addition polyimides. I. Kinetics of cure reaction and thermal decomposition of bismaleimides

Abstract

Abstract The thermal polymerization of four structurally different bismaleimide resins, prepared by reacting maleic anhydride with four aromatic diamines, viz., 4,4′‐diaminodiphenyl methane, 4,4′‐diamino diphenyl ether, 4,4′‐diamino diphenyl sulfone, and 3,3′‐diamino diphenyl sulfone, was followed by differential scanning calorimetry (DSC). The enthalpy change and the kinetic constants for the polymerization reactions were evaluated from the DSC curves. Thermal stability of the cured polymers was studied by thermogravimetry (TG). The kinetic parameters, viz., activation energy E and preexponential factor A , for the thermal decomposition of the cured bismaleimides were calculated from the TG curves using three nonmechanistic integral equations. The kinetic constants ( E and A ) follow a trend similar to the thermal stability of the polymers.