Patent GB-659083-A (GB)
Title: A process for the preparation of reaction products of polydienes with sulphur dioxide
IPC: C08C19/20
Filed: 1948-06-16
Abstract: A solution of a polydiene is mixed with an unsaturated compound of low molecular weight, the mixture is activated with oxygen or an oxygen-releasing substance which, if it is not a hydroperoxide, must be applied together with an ether, and is then contacted with sulphur dioxide.  "Polydiene" includes natural rubber and polymers and copolymers of conjugated dienes with 4 to 6 carbon atoms, containing a plurality of unsaturated carbon to carbon linkages and having a molecular weight of at least 5000. Specified are polymers of butadiene, methyl or dimethyl butadiene, or pentadiene, copolymers of mixtures of these compounds and with alkenes, e.g. isobutene.  The unsaturated compounds of low molecular weight must have at least one unsaturated carbon-to-carbon linkage and a molecular weight under 5000, and may be polymerization products.  Examples are butadiene, 1.5-hexadiene, allyl alcohol, chloride, acetate, capronate, isothiocyanate or oleate, o-diallyl phthalate or diallyl adipate. They may be substituted with halogens or polar groups such as OH, NH2, NH, CNO, CNS and NCS.  Suitable activators are hydrogen peroxide, ethyl hydroperoxide, tert.-butyl hydroperoxide, peracetic acid, cyclohexene peroxide, methyl-cyclohexene peroxide, tetra- and deca-hydronaphthalene peroxides and octahydroanthracene peroxide. The sulphur dioxide is preferably employed in solution of which the solvent may be miscible with that for the polydiene.  The reaction products may be obtained in the form of threads, fibres, bands or films by extruding the solution of polydiene and low molecular compound, containing a hydroperoxide, through a narrow orifice into a solution of sulphur dioxide in, e.g., ethyl alcohol, coagulation occurring immediately.  Specifications 611,919 and 616,276 are referred to.ALSO:A solution of natural rubber is mixed with an unsaturated compound of molecular weight below 5000, the mixture is activated with oxygen or an oxygen-yielding substance which, if it is not a hydroperoxide, must be applied together with an ether, and is then contacted with sulphur dioxide.  The low molecular compounds must have at least one unsaturated carbon-to-carbon linkage and may be polymerization products.  Examples are butadiene, 1,5-hexadiene, allyl alcohol, chloride, acetate, capronate, isothiocyanate, oleate, o-diallyl phthalate and diallyl adipate.  They may be substituted with halogens or polar groups such as OH, NH2, NH, CNO, CNS and NCS. Suitable activators are hydrogen peroxide, ethyl hydroperoxide, tert.-butyl hydroperoxide, peracetic acid, cyclohexene peroxide, methyl cyclohexene peroxide, tetra.- and deca-hydronaphthalene peroxides and octa-hydroanthracene peroxide.  The sulphur dioxide is preferably used in solution of which the solvent may be miscible with that for the rubber.  The reaction products may be obtained in the form of threads, fibres, bands or films by extruding the solution of rubber, low molecular compound, and hydroperoxide, in e.g. a benzene-toluene mixture, through a narrow orifice into a solution of sulphur dioxide in e.g. ethyl alcohol, coagulation occurring immediately. Specifications 611,919 and 616,276, [both in Group IV (a)], are referred to.