Abstract: The present invention provides a method for preparing alkenylsilanes whereby a gaseous mixture consisting essentially of an acetylenic hydrocarbon and a silane containing a silicon-bonded hydrogen atom is directed into contact with a reaction medium in the form of a relatively thin moving liquid layer or film. The reaction medium comprises a solubilized hydrosilylation catalyst and the alkenylsilane produced as a product of the reaction. The reaction medium can optionally include an organic liquid that is a solvent for the catalyst, alkenylsilane and acetylenic hydrocarbon reactant.

Abstract: What is disclosed is a process for the rearrangement of cylcoorganopolysilazanes to cycloorganotrisilazanes using quaternary ammonium halides as a catalyst. The quaternary ammonium halide has the formula R.sup.i.sub.4 NX where at least one R.sup.i is a group containing greater than 11 carbon atoms and X is a halogen atom. The rearrangement process is ran either as a batch or a continuous distillation procedure.

Abstract: What is disclosed is a process for converting polydiorganosiloxanes to cyclopolydiorganosiloxanes with reduced cleavage of organic groups from silicon atoms. The process comprises (A) feeding a mixture of the polydiorganosiloxanes, a catalyst, and an organic solvent to a device in which water is formed as the polydiorganosiloxanes react in the presence of the catalyst and the organic solvent, the water formed being driven out of said device as a two-phase organic solvent/water azeotrope; (B) reacting the polydiorganosiloxane/catalyst/organic solvent mixture from (A), essentially free of water, to convert the polydiorganosiloxanes to the desired product cyclopolydiorganosiloxanes; and (C) recovery of the desired product cyclopolydiorganosiloxanes.