Abstract: The present invention relates to a process for the production of an intermediate siloxane monomer and use of said monomer to produce high molecular weight linear polysilalkylenesiloxanes. The siloxane monomer is prepared by ring opening polymerization of a cyclic monomer of the structure in the presence of an acidic or basic ring opening polymerization catalyst; to form a mixture of siloxane monomers and linear oligomers. The linear oligomers are then extracted and discarded before a further step of ring opening polymerization using the aforementioned intermediate siloxane monomer mixture as the starting material. The second polymerization step is undertaken at a temperature within the melting point range of said siloxane monomer mixture. The intermediate, final product and methods of their manufacture are described.

Abstract: The present invention relates to a process for the production of an intermediate siloxane monomer and use of said monomer to produce high molecular weight linear polysilalkylenesiloxanes. The siloxane monomer is prepared by ring opening polymerization of a cyclic monomer of the structure in the presence of an acidic or basic ring opening polymerisation catalyst; to form a mixture of siloxane monomers and linear oligomers. The linear oligomers are then extracted and discarded before a further step of ring opening polymerization using the aforementioned intermediate siloxane monomer mixture as the starting material. The second polymerisation step is undertaken at a temperature within the melting point range of said siloxane monomer mixture. The intermediate, final product and methods of their manufacture are described.

Abstract: There is disclosed an improved method for preparing a hybrid organodisilanol compound having the formulaHO--R.sup.1 R.sup.2 SiC.sub.n H.sub.2n RC.sub.n H.sub.2n SiR.sup.1 R.sup.2 --OH (I)said method comprising:(A) reacting a dihydridosilane of the formulaR.sup.1 R.sup.2 SiH.sub.2 (II)with a diene of the formulaC.sub.n H.sub.2n-1 RC.sub.n H.sub.2n-1 (III)to provide a dihydrido compound of the formulaH--R.sup.1 R.sup.2 SiC.sub.n H.sub.2n RC.sub.n H.sub.2n SiR.sup.1 R.sup.2 --H (IV); and(B) reacting said dihydrido compound (IV) with a buffered water solution in the presence of a palladium catalyst.