Abstract: This invention provides curable compositions comprising a polytitanosiloxane containing at least two alkenyl radicals per molecule and a crosslinking agent that is either 1) the combination of an organohydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule and a platinum-containing catalyst or 2) an organic peroxide. This invention also provides a method for curing a polytitanosiloxane by reacting it with the crosslinking agent of the present compositions.

Abstract: The invention is a method for the preparation of organic solvent-soluble polytitanosiloxanes that contain units with the formulas R.sup.1.sub.a R.sup.2.sub.(3-a) SiO.sub. 1/2 (M units), SiO.sub. 4/2 (Q units) and TiO.sub. 4/2. The method comprises hydrolyzing tetraalkyl titanate or a partial hydrolyzate-condensate thereof and tetraalkyl silicate or a partial hydrolyzate-condensate thereof using water in an amount which is less than 80% of the amount theoretically necessary for the hydrolysis of all the alkoxy groups, and reacting the cohydrolyzate-cocondensate with at least 1 silane compound with the formula R.sup.1.sub.a R.sup.2.sub.3-a) SiOR.sup.3, where in the preceding formulas, R.sup.1 is the hydrogen atom or a monovalent organic group, R.sup.2 is a monovalent organic group, R.sup.3 is the hydrogen atom or an acyl group having no more than 8 carbon atoms, and a is an integer with a value of 0 to 3.