Disclosed is a composition comprising an electrophile, a nucleophile, and a thermally conductive filler package. The filler package may comprise thermally conductive, electrically insulative filler particles that may have a thermal conductivity of at least 5 W/m.K (measured according to ASTM D7984) and a volume resistivity of at least 10 Ω•m (measured according to ASTM D257, C611, or B193) and that may be present in an amount of at least 90 % by volume based on total volume of the filler package. The thermally conductive filler package may be present in an amount of at least 10 % by volume percent based on total volume of the composition. The present invention also is directed to a method for treating a substrate and to substrates comprising a layer formed from a compositions disclosed herein.