Abstract: A composition contains filler particles dispersed in a matrix material, wherein the matrix material contains: (a) 0.01 to 1.50 weight-percent of a first polyorganosiloxane, wherein first polyorganosiloxane is a linear polyorganosiloxane with an average of 2 or more carboxylic acid groups per molecule; and (b) 5 to 30 weight-percent of a second polyorganosiloxane that is free of carboxylic acid groups, wherein the second polyorganosiloxane is a liquid at 25 degrees Celsius and 101 megaPascals pressure; wherein the filler particles are present at a concentration in a range of 15 to less than 78 volume-percent based on composition volume and weight-percent values are relative to weight of the composition and wherein the composition is free of at least one of aliphatic diols and silicone polyethers.

Abstract: A composition contains filler particles dispersed in a matrix material, wherein the matrix material includes: (a) a first polyorganosiloxane that comprises an average of 2 or more succinic anhydride groups per molecule; and (b) a second polyorganosiloxane other than the first polyorganosiloxane; wherein the filler particles are present at a concentration in a range of 15 to 80 volume-percent based on composition volume and wherein the first polyorganosiloxane is present at a concentration sufficient to provide succinic anhydride groups at a concentration of 0.30 to 200 micromoles per gram of matrix material.

Abstract: A composition contains the following components: (a) 15 to 49.8 volume-percent of a first polysiloxane that is has a viscosity in a range of 50 centiStokes to 550 Stokes as determined according to ASTM D4283-98; (b) 0.2 to 5 volume-percent of an organoclay; (c) 50-74 volume-percent roundish or crushed thermally conductive fillers including: (i) 5 to 15 volume-percent small thermally conductive fillers having a median particle size in a range of 0.1 to 1.0 micrometers; (ii) 10 to 25 volume-percent medium thermally conductive fillers having a median particle size in a range of 1.1 to 5.0 micrometers; (iii) 25 to 50 volume-percent large thermally conductive fillers having a median particle size in a range of 5.1 to 50 micrometers; and (d) 0 to 5 volume-percent of an alkoxy functional linear polysiloxane different from the first polysiloxane and/or an alkoxy functional linear silane; where volume-percent values are relative to composition volume.

Abstract: A composition contains the following components: (a) 15 to 49.8 volume-percent of a first polysiloxane that is has a viscosity in a range of 50 centiStokes to 550 Stokes as determined according to ASTM D4283-98; (b) 0.2 to 5 volume-percent of an organoclay; (c) 50-74 volume-percent roundish or crushed thermally conductive fillers including: (i) 5 to 15 volume-percent small thermally conductive fillers having a median particle size in a range of 0.1 to 1.0 micrometers; (ii) 10 to 25 volume-percent medium thermally conductive fillers having a median particle size in a range of 1.1 to 5.0 micrometers; (iii) 25 to 50 volume-percent large thermally conductive fillers having a median particle size in a range of 5.1 to 50 micrometers; and (d) 0 to 5 volume-percent of an alkoxy functional linear polysiloxane different from the first polysiloxane and/or an alkoxy functional linear silane; where volume-percent values are relative to composition volume.