Disclosed herein are methods of preparing an aminimide. An epoxy compound is reacted with a hydrazine compound comprising a trivalent nitrogen, and an anhydride functional material or a cyclic compound containing a carbonyl group and at least one heteroatom alpha to the carbonyl group at a temperature greater than 20° C. to form the aminimide. At least one of the epoxy compound and the anhydride functional material or the cyclic compound is polymeric.