Abstract: Bisphosphine oxide monomers and homologs thereof may be incorporated into polycarbonates in order to obtain a flame retardant polymer. More particularly, bis[2,5-(diphenylphosphine oxide)]-1,4-hydroquinone and homologs thereof may be used to prepare flame retardant polycarbonates that retain high glass transition temperature and high impact resistances.

Abstract: In the production of a triorganylsily or organodiorganylsilyl end-terminated poly-(diorganosiloxane) by reacting an .alpha.,.omega.-dihydroxypoly(diorganosiloxane) with a tetraorganyloxysilane or organotriorganyloxysilane in the presence of at least one alkali hydroxide, alkali alkoxide or alkali silanolate as a catalyst, the improvement which comprises effecting the reaction also in the presence of additionally at least one alkali metal salt which is soluble in the reactive system.

Abstract: Organo(poly)siloxanes with siloxane units at the end of the chain having organyloxy and hydrogen groups are disclosed as well as a process for producing the same by reacting .alpha.,w-dihydroxyorgan(poly)siloxanes with silanes having a group that can be easily separated and their use in organo(poly)siloxane mixtures that can be stored in the absence of water but which can be cross-linked into elastomers at ambient temperature in the presence of water. Also, a process is disclosed for producing organopolysiloxane elastomers by cross-linking cross-linkable mixtures by addition of Si-linked hydrogen to SiC-linked residues with aliphatic carbon-carbon multiple linkage.

Abstract: A method for the preparation of a random diorganosiloxane-diorganosilazane copolymer is disclosed, which method comprises polymerizing(A) a mixture or polymerization reaction product of(a) a hexaorganodisiloxane and(b) a cyclic diorganosiloxane with(B) a cyclic diorganosilazane of the formula ##STR1## wherein R.sup.1 is a monovalent hydrocarbon group, R.sup.2 is hydrogen or a monovalent hydrocarbon group and n is 3 or 4, the polymerization being carried out in the presence of cesium hydroxide.

Abstract: The present invention relates to a process for preparing an alkoxy silyl-terminated material, which has at least one alkoxy group on at least one terminal end, said process comprising reacting in the presence of a catalytically effective amount of an organo-lithium reagent an alkoxysilyl-terminated first reactant with a second reactant having at least one end of its chain terminating in silanol groups. The alkoxy silyl-terminated material may have a variety of polymer backbone types such as silicone, polyurethane, polyamide and the like. These materials are intended to cure by either moisture cure or by dual moisture and photo cure mechanisms. The alkoxy silyl-terminated material is preferably an organopoly-siloxane having alkoxy groups at its terminal ends. The resultant alkoxy-terminated organopolysiloxanes are substantially stable materials as measured by preservation and maintenance of viscosity values (cps) over time.

Abstract: The invention provides a method for manufacturing an alkoxy radical-containing silicone resin wherein the molecular weight, viscosity, thermal transition point, and alkoxy radical content can be easily controlled. The method of the instant invention comprises combining under anhydrous conditions, (A) an alkoxysilane represented by the formula R.sup.4.sub.a Si(OR.sup.5).sub.4-a or its partial hydrolysis product wherein R.sup.4 is selected consisting of a monovalent hydrocarbon radical and a monovalent halogenated hydrocarbon radical, R.sup.5 is selected from the group consisting of an alkyl radical containing 1 to 6 carbon atoms, and a has a value of 0 to 3; and (B) an organopolysiloxane or a mixture of organopolysiloxanes selected from the group consisting of organopolysiloxanes that are made of siloxane units selected from the group consisting of R.sup.1 SiO3.sub./2 and R.sup.2 R.sup.3 SiO and mixtures thereof wherein R.sup.1, R.sup.2 and R.sup.

Abstract: Silicone resins containing monorganosiloxane and diorganosiloxane units and exhibiting reproducible values of molecular weight and dispersity are prepared by condensing a mixture of hydrolyzed silanes, adjusting the solids content of the condensed resin and then subjecting the resultant product to a re-equilibration reaction in the presence of an alkali metal compound.

Abstract: The present invention relates to novel fluorosilicone block copolymers and to a method for their preparation. More specifically, the present invention relates to fluorosilicone block copolymers that are composed of poly(perfluoroalkylmethylsiloxane) and polydimethylsiloxane chains and also to a method for the preparation of these fluorosilicone block copolymers.

Abstract: A silicone rubber composition comprising(A) 100 parts by weight of a polyorganosiloxane having, per molecule, at least two structural units represented by the following formula:(R.sup.1).sub.a (R.sup.2).sub.b SiO.sub.(4-(a+b))/2 (I)(B) a polyorganohydrogensiloxane comprising structural units shown by the following formula:(R.sup.3).sub.c H.sub.d SiO(4-(c+d))/2 (II)and having at least three silicon-bonded hydrogen atoms per molecule, the amount of component (B) being such that the number of silicon-bonded hydrogen atoms in component (B) is from 0.5 to 4.0 per R.sup.1 group in the structural units shown by formula (I) of component (A),(C) from 0.1 to 10 parts by weight of a compound selected from the group consisting of an organosilicon compound having, per molecule, at least one silicon-bonded hydrogen atoms and at least one group represented by the following formula: ##STR1## and an acrylic- or methacrylic-functional silane coupling agent, (D) from 0.

Abstract: A method for producing, in the presence of both monomers, a block copolymer of a polymer block of a vinyl aromatic hydrocarbon (and/or a conjugated diene) and a block of polydimethysiloxane which comprises adding a vinyl aromatic hydrocarbon, an organo alkali metal promoter, hexamethylcyclotrisiloxane and a polar promoter to a solvent (or to the styrene if no solvent is to be used) at a temperature of 0.degree. to 60.degree. C., allowing the polymerization of the vinyl aromatic hydrocarbon to proceed until the color of the vinyl aromatic hydrocarbon - Li.sup.+ species which is initially produced fades, then raising the temperature to 60.degree. to 120.degree. C. wherein the hexamethylcyclotrisiloxane polymerizes at the end of the polystyrene polymer blocks and then terminating the polymerization.

Abstract: Cyclopentadienyl and/or cyclopentadienylene and/or dicyclopentadienylene-substituted polyorganosiloxanes that are crosslinkable into elastomeric state on exposure to atmospheric oxygen and/or to moisture are well suited, e.g., for adhesive applications in the construction industry and for diverse insulating/coating applications.

Abstract: The invention provides a thermal and addition curable silicone release coating comprising a mixture of an epoxysilicone controlled release additive containing at least one tri- or quadri-functional siloxane unit, a vinyl-functional silicone base polymer, a temperature-dependent hydrosilation inhibitor and an effective hydrosilation catalyst.

Abstract: The invention relates to a series of novel silicone alkoxylates a process for their preparation and the application of these materials as emulsifiers for a variety of oil phases. This class of compounds are prepared by the reaction of a carboxy functional silicone and a ethylene oxide, propylene oxide or mixtures thereof. The products provide unique surfactant properties, specifically emulsification properties for many oil phases.The compounds are useful for preparation of ultra mild products for use personal care applications for skin, hair care and related applications.

Abstract: Silethynylenedisiloxane polymers are described with repeating units represented by --R.sup.1 R.sup.2 SiC.tbd.CSiR.sup.3 R.sup.4 OSiR.sup.5 R.sup.6 O-- where R.sup.1 -R.sup.6 independently represent hydrogen atoms, alkyl groups, aryl groups, or alkenyl groups. The polymers are prepared by reacting a disilylacetylene compound represented by the formula X.sup.1 R.sup.1 R.sup.2 SiC.tbd.CSiR.sup.3 R.sup.4 X.sup.1 and a silane compound represented by the formula X.sup.2.sub.2 SiR.sup.5 R.sup.6 where X.sup.1 and X.sup.2 represent H, OH, OM, or a hydrolyzable group. X.sup.1 and X.sup.2 are not identical and are selected so that they undergo a condensation reaction to form a siloxane bond.

Abstract: The present invention is an improvement upon the process for making block copolymers of vinyl aromatic hydrocarbons and/or conjugated dienes, and polydimethylsiloxane by first anionically polymerizing the vinyl aromatic hydrocarbon to make a living polymer block and then adding hexamethylcyclotrisiloxane and a polar promoter to polymerize a polydimethylsiloxane block at the end of the living polymer block. The improvement comprises reacting the living polymer blocks with a crossover reagent to decrease the crossover time from the living polymer block polymerization to the polydimethylsiloxane polymerization.

Abstract: A method of manufacturing aminogroup-containing polysiloxanes of uniform quality characterized in that a cyclic organopolysiloxane represented by the following general formula: ##STR1## and an aminoalkylpolysiloxane represented by the following general formula: ##STR2## are heated together in the presence of a basic catalyst.

Abstract: The introduction of a branched organopolysiloxane in which polysiloxane with the formula SiO.sub.2 constitutes the branching center or branch origin and the terminal on only one side of diorganopolysiloxane is bonded to the branch origin wherein this bonding is exactly to the branch origin. The branched organopolysiloxane is described by formula(SiO.sub.4/2).sub.x (R.sup.1.sub.2 ASiO.sub.1/2).sub.y (R.sup.1.sub.3 SiO.sub.1/2).sub.z (RO.sub.1/2).sub.u,wherein each R.sup.1 is independently selected from a group consisting of C.sub.1-8 alkyls, haloalkyls, alkenyls, and aryls; A is described by formula--(OSiR.sup.2 R.sup.3)n--R.sup.4wherein R.sup.2 and R.sup.3 are independently selected from a group consisting of C.sub.1-8 alkyls, haloalkyls, alkenyls, and aryls, R.sup.4 is selected from a group consisting of C.sub.1-8 alkyls, haloalkyls, alkenyls, hydrogen atom and hydroxyl, and 1.ltoreq.n.ltoreq.1,000; R is selected from a group consisting of hydrogen atom and C.sub.1-8 alkyls; 2.ltoreq.x.ltoreq.500; 0.ltoreq.

Abstract: Organosilicon compounds with a siloxane portion and groups of the general formula --OR'OCH.dbd.CHR'' (i) linked via an Si--O--C bond, wherein R' is a divalent hydrocarbon radical or a group --R.degree.--(OR.degree.).sub.n --, wherein R.degree. is alkylene and n is from 1 to 12, R'' is H or alkyl are useful in radiation curable compositions, in which they are mixed with an initiator. The compositions are particularly useful in UV radiation curable relase coatings.

Abstract: The invention provides a method for making an epoxysilicone compound through the hydrosilation addition reaction between an ethylenically unsaturated epoxide and an SiH-containing silicon to produce an epoxysilicone product, and catalyzed by a regiospecific hydrosilation catalyst which does not also promote an oxirane ring-opening polymerization reaction in either the ethylenically unsaturated epoxide starting compound or in the epoxysilicone hydrosilation reaction product. The invention also provides a hydrosilation catalyst with the above catalytic properties as well as an epoxysilicone composition made by the above method.

Abstract: Process for the production of organosiloxanes comprising contacting (A) at least one organosilicon compound having in the molecule at least one silanol group, the organic substituents being selected from monovalent hydrocarbon groups having from 1 to 14 carbon atoms and monovalent substituted hydrocarbon groups having from 1 to 10 carbon atoms, with (B) one or more compounds selected from rubidium carbonate, cesium carbonate and carboxylates of rubidium and cesium.

Abstract: The molecular weight distribution of polydimethylsiloxane-.alpha., .omega.-diol fluids is reduced by contacting the fluid with an alkaline earth metal hydride or hydroxide. Molecular weight distributions lower than Poisson distributions may be obtained. The resulting monodispersed polydimethylsiloxane.alpha., .omega.-diol fluids may be substituted by reaction with common silanating reagents to prepare telechelic polydimethylsiloxanes which are nearly monodispersed.

Abstract: The present invention is a method for the preparation of branched organopolysiloxane in which polysiloxane with the formula SiO.sub.2 constitutes the branching center or branch origin and the terminal on only one side of diorganopolysiloxane is bonded to the branch origin wherein this bonding is exactly to the branch origin. Specifically, the method for preparation of branched polyorganosiloxane comprises the reaction of an alkali metal compound with a silanol-containing polysiloxane described by formula{SiO.sub.4/2 }.sub.x {R.sup.1.sub.2 (OH)SiO.sub.1/2 }.sub.y {R.sup.1.sub.3 SiO.sub.1/2 }.sub.z {RO.sub.1/2 }.sub.u,wherein each R.sup.1 is independently selected from a group consisting of C1-8 alkyls, haloalkyls, alkenyls, and aryls; R is selected from a group consisting of hydrogen atom and C1-8 alkyls; 2.ltoreq.x.ltoreq.500; 2.ltoreq.y+z+u.ltoreq.150; 2.ltoreq.y; 0.ltoreq.z; 0.3 .ltoreq.(y+z+u)/x.ltoreq.3; and 0.ltoreq.u/(x+y+z).ltoreq.0.

Abstract: A process for preparing metallopolysilanes, which comprises reacting at least one disilane of the general formulaR.sub.6-n Si.sub.2 (OR.sup.1).sub.n (I)in which R may be the same or different and is a hydrogen atom or a monovalent hydrocarbon radical, R.sup.1 is the same or different monovalent alkyl groups, and n is 2, 3, 4, 5 or 6, and optionally mixed with at least one compound of the general formulaR.sup.2.sub.4-m Si(OR.sup.4)m (II)in which R.sup.2 may be the same or different and is the same as R, R.sup.4 may be the same or different and is the same as R.sup.1, and m is 1, 2, 3 or 4, with at least one compound of the general formula(R.sup.5 O)[A(OR.sup.5).sub.a-2.sup.O].sub.x R.sup.5 (III)in which R.sup.5 may be the same or different and is the same as R.sup.1, A is a metal from group IIa, IIIa, IVa, Va, IIIb, IVb or Vb of the Periodic Table, x is an integer of from 1 to 1,000, and a represents the valency of A, in the presence of at least one compound of the general formulaMOR.sup.3 (IV)in which R.sup.

Abstract: The heat stability of acrylamide functional polydiorganosiloxanes which cure by exposure to ultraviolet radiation can be improved by the addition of nickel carboxylate, stannous naphthenate, cerium carboxylate, manganese carboxylate, aluminum carboxylate, silver carboxylate, copper undecylenate, cobalt carboxylate, mono(methacrylate) tripropoxyzirconate, mono(ethylacetoacetonate) aluminum di-(sec-butoxide), di-(ethylacetoacetonate) aluminum sec-butoxide, zinc acetylacetonate, molybdenum acetylacetonate, and dibutyltin dicarboxylate.

Abstract: A method of making silethynyl polymers having units of the general formula--(R.sub.2 SiC.tbd.C)-- wherein each R independently denotes a hydrogen atom, an alkyl, aryl or alkenyl group or a substituted alkyl, aryl or alkenyl group having up to 18 carbon atoms comprises adding a lithium salt of one or more diethynylsilanes of the general formula R.sub.2 Si(C.tbd.CH).sub.2 to one or more dihalosilanes of the general formula R.sub.2 SiX.sub.2 where X is a halogen atom and allowing the components to react. Copolymers with alternating units can be made. Linear polymers are made preferentially. Limiting the use of solvent increases the percentage of linear polymers produced.

Abstract: Low-molecular-weight phenylpolysilsesquioxanes that have narrow molecular weight distribution and a method for the preparation of the same.

Abstract: A reaction of perfluoroolefins with bis(silyl) ethers to produce novel partially fluorinated and perfluorinated copolymers and macrocyclic compounds is disclosed.

Abstract: A novel and efficient method is disclosed for decreasing the content of residual alkoxy groups in an organopolysiloxane such as so-called MQ resins, usually and unavoidably, having a considerable amount of residual alkoxy groups bonded to the silicon atoms to be very detrimental against practical application of the organopolysiloxane. The method comprises admixing the alkoxy-containing organopolysiloxane with a strongly alkaline compound such as alkali metal hydroxides as a catalyst, an aprotic polar solvent such as N,N-dimethyl formamide, dimethyl sulfoxide and the like and water each in a specified amount and heating the mixture, for example, under reflux so that the alkoxy groups are rapidly hydrolyzed and can be removed in the form of an alcohol.

Abstract: Polysilanes are synthesized by reacting dihalosilanes in the presence of alkali metal particles while using copper powder, cuprous oxide, cupric oxide, or an organic copper compound as a catalyst. There are obtained high molecular weight polysilanes in high yields.

Abstract: Block copolymers of the formula ##STR1## wherein R.sub.1, R.sub.2, and R.sub.3 are independently selected from the group consisting of hydrogen, alkyl and aryl; k, j, m and n represent the number of repeating segments, and imaging members thereof.

Abstract: A method for deodorizing polyoxyalkylene polysiloxane mixed block polymers wherein the polysiloxane blocks are linked to the polyether blocks through SiC linkages is disclosed. Hydrogen is allowed to act on the mixed block polymers in the presence of hydrogenation catalysts at temperatures of 20.degree. to 200.degree. C. and a pressure of 1 to 100 bar for a period of 0.5 to 10 hours.

Abstract: A composition which is an anhydrous organic solvent free mixture of a hydrolyzable silane monomer; silanols formed by hydrolysis of the silane monomer; alkoxy functional oligomers formed by condensation of the silanols such as dimers and trimers; and higher alkoxy functional oligomers such as tetramers. Methods of making and using the composition are described.

Abstract: A process for preparing organo(poly)siloxanes of the formulaR.sup.1 R.sub.2 Si(OSiR.sub.2).sub.m (OSiR.sub.2).sub.n OHwhich comprises reacting a hexaorganocyclotrisiloxane of the formula(R.sub.2 SiO).sub.3with a sil(ox)anol of the formulaR.sup.1 R.sub.2 Si(OSiR.sub.2).sub.m OHin the presence of a catalyst which contains fluoride ions, in which R is the same or different and represents a monovalent, optionally substituted hydrocarbon radical, R.sup.1 represents a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical, m is 0 or an integer of at least 1 and n is an integer of at least 3.An alkali metal fluoride or an alkali metal fluoride bonded to a support material is preferably used as the catalyst in the process of this invention.

Abstract: A method of making silethynyl polymers having units of the general formula --(R.sub.2 SiC.tbd.C)-- wherein each R independently denotes a hydrogen atom, an alkyl, aryl or alkenyl group or a substituted alkyl, aryl or alkenyl group having up to 18 carbon atoms comprises adding a lithium salt of one or more diethynylsilanes of the general formula R.sub.2 Si(C.tbd.CH).sub.2 to one or more dihalosilanes of the general formula R.sub.2 SiX.sub.2 where X is a halogen atom and allowing the components to react. Copolymers with alternating units can be made. Linear polymers are made preferentially. Limiting the use of solvent increases the percentage of linear polymers produced.

Abstract: Polymeric stabilizers having a polysiloxanic structure contain reactive groups which can be linked to the polymeric structure to be stabilized and sterically hindered piperidinic groups. These polymeric stabilizers are particularly suitable for the stabilization of organic polymers against U.V. radiation and heat, when it is required for them not to be extracted by solvents, fats or soaps.

Abstract: Block copolymers having a repeating unit comprised of polysiloxane and urea segments are prepared by copolymerizing certain diaminopolysiloxanes with diisocyanates. The invention also provides novel diaminopolysiloxanes useful as precursors in the preparation of the block copolymers and a method of making such diaminopolysiloxanes. Pressure sensitive adhesive compositions comprising the block copolymer are also provided as are sheet materials coated with the same.

Abstract: A process for preparing a high molecular weight organopolysiloxane comprising: a first polymerization step of bringing a low molecular weight organopolysiloxane into reaction in the presence of a quaternary phosphonium hydroxide compound and/or a silanolate thereof as a catalyst under heating; and a second polymerization step for bringing the resulting reaction mixture into reaction in the presence of an alkali metal hydroxide and/or a silanolate thereof as a catalyst under heating. According to the process, a high molecular weight organopolysiloxane can be prepared using a reduced amount of catalyst for polymerization reaction, so that the amount of salts formed from a neutralizing agent is smaller and the subsequent filtration step for purification is less burdensome and easier to carry out.

Abstract: A method of making a dispersion of a high viscosity siloxane in a volatile, especially cyclic siloxane, comprises first dispersing organopolysiloxanes having at least 2 Si--OR groups, wherein R is H or alkyl in a volatile siloxane and adding a catalyst which is either a phosphonitrile halide having the general formula [X(PX.sub.2 .dbd.N).sub.n PX.sub.3 ].sup.+ [MX.sub.(v-t+1) R.sub.t ].sup.-, or a heterogeneous catalyst selected from Li, Mg, Ca, Sr or Ba hydroxide, Na or K borate or phosphate, Rb or Cs carbonate or carboxylates of Rb or Cs wherein M is an element having an electronegativity of from 1.0 to 2.0, R is alkyl, X is halide, n is 1 to 6, v is the valence of M and t is from 0 to (v-1).

Abstract: A method of making organopolysiloxanes comprises contacting organosilicon compounds having at least one unit ##EQU1## wherein R.degree. is hydrogen, hydroxyl, a C.sub.1-18 hydrocarbon, substituted hydrocarbon or hydrocarbonoxy group and a has a value of from 0 to 4 with a phosphonitrile halide AB, wherein A is a phosphonitrile halide cation [X(PX.sub.2 .dbd.N).sub.n PX.sub.3 ].sup.+, wherein X is halide and n is from 1 to 8 and B is an anion derived from a Lewis acid not containing a P atom, e.g. [MX.sub.(v-t+1) R.sup.2 .sub.t ].sup.-. The method is particularly useful for condensation of silanol end-blocked siloxanes.

Abstract: An organopolysiloxane containing at least one epoxy group is produced by heating a mixture of (a) an epoxy group-containing organosiloxane; (b) an organosiloxane lacking an epoxy group and optionally containing an arkenyl group; (c) an aprotic polar organic solvent; and (d) a basic catalyst, until reaction between (a) and (b) by a disproportionation equilibration reaction occurs.

Abstract: Polycarbosilanes having Si units which are linked by phenyl-substituted methylene bridges or by partially or completely fluorinated hydrocarbon bridges. These polycarbosilanes are obtained by a Grignard polycondensation reaction. If phenyl substituents are present on the silicon atoms of the polycarbosilanes, they may also optionally be exchanged for halogen atoms in additional halogenating reactions, so that polycarbosilanes can be prepared which are both fluorinated on the hydrocarbon bridges and halogenated (particularly fluorinated) on the silicon atoms.

Abstract: A method of forming modified preceramic polymers comprising mixing organopolysilanes having a plurality of Si--H functional groups with an effective amount of a metallocene compound, and allowing the mixture to undergo a dehydrogenative reaction is disclosed. Pyrolysis of the modified polymer provides in high yields ceramic residues that approach stoichiometric SiC in composition. Preferably the organopolysilane starting material contains a plurality of tertiary Si--H bonds and has the general formula of [(RSiH).sub.x (RSi).sub.y ].sub.n where the sum of the coefficients x and y equal 1, n is an integer greater than 1, R is a lower alkyl group having from 1 to about 8 carbon atoms, a substituted or unsubstituted lower alkenyl group having from 2 to about 8 carbon atoms, a cycloalkyl group having from 3 to about 10 carbon atoms, substituted or unsubstituted aryl group having from 6 to about 10 carbon atoms.

Abstract: Silicone block polymers are obtained by cohydrolysis of a both end reactive diorganopolysiloxane and a silane or a partial hydrolyzate thereof or curing a both end reactive diorganopolysiloxane and an organopolysiloxane at room temperature or elevated temperatures. They have improved flexibility, stain resistance, thermal shock resistance, and water repellency and are suitable to form hard coatings, moistureproof coatings and topcoats.

Abstract: Polyorganosiloxane resins are prepared through the hydrolytic condensation of organoalkoxysilanes and/or oligomers thereof. By adding a low volatile, weakly acidic compound to the reaction mixture for adjusting the reaction mixture to pH 2-5, the alcohol by-product can be distilled off from the reaction mixture without altering the polyorganosiloxane resins.

Abstract: The present invention relates to a process for the production of diorganyloxyorganosilyl- or triorganyloxysilyl-terminated poly(di-organosiloxanes) by reaction of .alpha.,.omega.-dihydroxypoly(diorganosiloxanes) with alkoxysilanes in the presence of catalytically active strong alkali metal bases.

Abstract: The invention provides a high-sensitivity ultraviolet-curable organopolysiloxane composition suitable for use as a surface-release treatment of various substrate such as release-paper sheets and the like. The composition comprises, as the essential ingredients, (a) an organopolysiloxane having a viscosity in the range from 50 to 3000 centipoise at 25.degree. C. and containing, in a molecule, at least one (meth)acryloxy-substituted monovalent hydrocarbon group or at least one epoxy- or glycidyloxy-substituted monovalent hydrocarbon group, and (b) a sulfonate compound such as 2-hydroxy-3-oxy-2,3-diphenylpropyl methanesulfonate as the photopolymerization initiator. The sensitivity of the composition to photopolymerization can be further increased by the addition of a specific salt such as sodium hexafluoroantimonate and sodium hexafluorophosphate.

Abstract: The described process uses a Lewis base as a catalyst to effect the condensation of hydroxy end-substituted polyorganosiloxanes, in the presence of triorganosilyl endblocker to control polymer chain length. The inventors have discovered that within a base catalyst concentration range where the cation concentration is about 1.times.10.sup.-3 to 2.times.10.sup.-1 mole percent in relation to the silicon atoms present, the partial pressure of water can be controlled at a constant value to produce polyorganosiloxane polymers with a reproducible and predictable level of hydroxy substitution.

Abstract: Random or block copolymers with (1-hydro-1-R-1-sila-cis-pent-3-ene), poly(1-hydro-1-R-3,4 benzo-1-sila pent-3-ene), and disubstituted 1-silapent-3-ene repeating units of the general formula ##STR1## where R is hydrogen, an alkyl radical containing from one to four carbon atoms or phenyl, R.sup.1 is hydrogen, an alkyl radical containing from one to four carbon atoms, phenyl or a halogen and R.sup.2 is hydrogen, or R.sup.1 and R.sup.2 are combined to form a phenyl ring, are prepared by the anionic ring opening polymerization of silacyclopent-3-enes or 2-silaindans with an organometallic base and cation coordinating ligand catalyst system or a metathesis ring opening catalyst system.

Abstract: Poly(1-hydro-1-R-1-sila-cis-pent-3-ene) and poly(1-hydro-1-R-3,4 benzo-1-sila pent-3-ene) polymers having repeating units of the general formula ##STR1## where R is hydrogen, an alkyl radical containing from one to four carbon atoms or phenyl, R.sup.1 is hydrogen, an alkyl radical containing from one to four carbon atoms, phenyl or a halogen and R.sup.2 is hydrogen, or R.sup.1 and R.sup.2 are combined to form a phenyl ring, are prepared by the anionic ring opening polymerization of silacyclopent-3-enes or 2-silaindans with an organometallic base and cation coordinating ligand catalyst system.

Abstract: A process for the preparation of organopolysilanes which comprises reacting at least one disilane of the general formulaR.sub.k R.sup.3.sub.m Si.sub.2 (OR.sup.1).sub.6-k-m (I)in which the radicals R may be the same or different and are hydrogen atoms or monovalent, saturated organic radicals, the radicals R.sup.3 may be the same or different and are monovalent, unsaturated organic radicals, the radicals R.sup.1 may be the same or different and are monovalent alkyl groups, k is 0, 1, 2 or 3, and m is 1, 2, 3 or 4, in which the sum of k and m is less than or equal to 4, and optionally mixed with a disilane of the formulaR.sub.n Si.sub.2 (OR.sup.1).sub.6-n (II)in which R and R.sup.1 are the same as above and n is 0, 1, 2 or 3, in the presence of at least one compound of the general formulaMOR.sup.2 (III)in which R.sup.2 is a monovalent hydrocarbon radical and M is an alkali metal atom.