Disclosed are a reaction mixture for preparing a polyfunctional maleimide-based thermosettable resin composition comprising a bismaleimide or a polymaleimide and an ether derivative of an alkenylphenol; the polyfunctional maleimide-based thermosettable resins comprising the reaction product of the reaction mixture; a process for the manufacture of the resins; and their use in a prepreg containing carbon, boron. glass or other fibers.