US Patent 7432338 Branched polymers from organohydrogensilicon compounds

This invention relates to a method comprising (1) heating in the presence of a catalyst a mixture comprising (i) at least one organohydrogensilicon compound containing at least one silicon-bonded hydrogen atom per molecule or a reaction product obtained by mixing in the presence of a platinum group metal-containing catalyst at least one organohydrogensilicon compound containing at least one silicon-bonded hydrogen atom per molecule and at least one compound having at least one aliphatic unsaturation, (ii) at least one endblocker, and optionally (iii) at least one organosiloxane chosen from a hydrolyzate or a cyclosiloxane, so to cause polymerization of components (i), (ii), and optionally (iii) to form silicon-bonded hydrogen containing branched polymers.