Thermally conductive compositions include a blocked isocyanate prepolymer composition containing an isocyanate prepolymer blocked with one or more of alkylphenol or alkenylphenol; and an amine composition containing: one or more polyetheramines, and one or more plasticizers selected from esters of glycol ethers; and a thermally conductive filler present at a percent by weight of the thermally conductive composition (wt%) in a range of 60 wt% to 98 wt%; wherein the thermally conductive composition cures at a temperature in the range of 18oC to 35oC when the blocked isocyanate prepolymer composition and the amine composition are mixed.