Abstract:
The invention comprises organopolysiloxanes having at least one siloxane unit per molecule of the general formula or of the general formula in which Y is H, an aliphatic hydrocarbon or halohydrocarbon radical, a cycloaliphatic hydrocarbon or halohydrocarbon radical, an aralkyl or haloaralkyl radical or an acyl radical of the formula R11C = O in which R11 is a hydrocarbon or halohydrocarbon radical, m is 1 or 2, Me is a methyl radical, C is a tertiary carbon atom, R is a hydrocarbon radical of 1 to 11 C atoms, R1 is a monovalent hydrocarbon or halohydrocarbon radical of less than 7 C atoms and n is 0, 1 or 2, any remaining siloxane units in the siloxane being of the general formula ZaSiO 4-a/2, in which Z is a monovalent hydrocarbon or halohydrocarbon radical, a is 1, 2 or 3 and has an average value of at least 1 in the polymer. The peroxides can be made by reacting (a) the corresponding siloxane alcohols with H2SO4 to form the sulphate and then reacting the sulphate either with hydroperoxides (where Y is a saturated hydrocarbon or halohydrocarbon) or with H2O2 (where Y is H), or (b) the corresponding organosilicon hydroperoxides with an acyl chloride (where Y is an acyl group) in the presence of a hydrogen halide acceptor, e.g. pyridine; or (c) the K salts of the siloxane hydroperoxide with a halogenated olefin (where Y is an unsaturated hydrocarbon or halohydrocarbon). Another general method involves the selective oxidation of siloxanes of the formula by passing oxygen through the siloxane at 80 DEG to 105 DEG C. In Example (1) was reacted with in the presence of chloroplatinic acid to give the corresponding siloxane alcohol which was reacted with H2SO4, to give the sulphate and then with t-butylhydroperoxide to give a liquid peroxy siloxane of the formula In other examples similar reactions gave (2) a mixture or and (3) first the siloxane alcohol and then the peroxide (4) first the alcohol and then the peroxide (6) (7) and a copolymer of diethylsiloxane, monopropylsiloxane, cyclohexylsiloxane and a ,a ,a -trifluorotolylmethylsiloxane units; and (9) (5) Oxygen was passed over the surface of a heated (85 DEG C.) aqueous emulsion of to give (8) the method (c) above yielded (10) the hydroperoxide was reacted with different acyl halides to yield:- and (11, 12, 13) The peroxy-siloxanes of Examples 1, 2 and 4 were each milled with a vinyldimethylsilyl-terminated dimethylsiloxane gum and trimethylsiloxy surface-modified silica xerogel and heat cured. (14) A dimethylpolysiloxane gum, a liquid dimethylpolysiloxane, a 3,3,3-trifluoropropylmethylpolysiloxane gum and an ethylmethylpolysiloxane gum were each milled with fume silica and cured with the peroxysiloxanes of Example 1. (15) A dimethylpolysiloxane was vulcanized with each of the peroxysiloxanes of Examples 5 to 10. Uses: As catalysts for polymerizing olefins, vulcanizing silicone rubbers, curing silicone resins, and as intermediates in making organo-functional organosilicon compounds.