A curable composition for an electrical machine is presented. The curable composition includes: (A) about 10 weight percent to about 30 weight percent of a polyfunctional cyanate ester; (B) about 25 weight percent to about 60 weight percent of a first difunctional cyanate ester, or a prepolymer thereof; (C) about 10 weight percent to about 30 weight percent of a second difunctional cyanate ester, or a prepolymer thereof, and (D) about 5 weight percent to about 25 weight percent of a thermally conductive filler comprising boron nitride. An associated method is also presented.