Abstract: An adhesion promoter which is a silane or polysiloxane having in each molecule at least one organic group possessing aliphatic unsaturated group and at least one organic group possessing amino group or having in each molecule at least one organic group possessing both aliphatic unsaturation and an amino group is useful for improving the adhesion of radiation curable organopolysiloxane compositions to substrates.

Abstract: The combination of known thermally conductive fillers having an average particle size of from about 10 to about 100 microns with aluminum nitride having an average particle size of less than one micron improves the thermal conductivity of organosiloxane compositions. The thermal conductivity values achieved using this combination of fillers is higher than can be achieved using the maximum loading of either filler alone that can be present without adversely affecting the ability of the organosiloxane composition to cure or to serve as useful coatings and encapsulates for electronic solid state devices and other substrates.

Abstract: Silicone-polyarylene ether block copolymers are provided which can be made by effecting reaction between amino terminated polydiorganosiloxane and anhydride functionalized polyarylene ether.