Abstract: A method for chemical vapor deposition of a film comprising tantalum onto a substrate includes introducing into a deposition chamber: (i) a substrate; (ii) a source precursor in the vapor state; and (iii) at least one carrier gas, and maintaining the temperature of the substrate within the chamber as from about 70.degree. C. to about 675.degree. C. for a period of time sufficient to deposit a film comprising tantalum on the substrate. The source precursor has a formula (I):Ta(I.sub.5-m-n-p)(Br.sub.m- p)(Cl.sub.n- p)(R.sub.p) (I)wherein m is an integer from 0 to 5, n is an integer from 0 to 4, p is an integer from 0 to 4, and R is selected from the group consisting of hydrogen, and lower alkyl.

Abstract: A branched alkylsilane includes a branched hydrocarbon backbone which has a linear or branched alkylsilyl moiety extending asymmetrically from the backbone such that the backbone has a first portion and a second portion extending from the moiety. The second portion has two carbon atoms more than the first portion, and the alkylsilyl moiety includes at least one hydrolyzable group bound to silicon for reacting with a substrate. A method for preparing a branched alkylsilane useful for chromatographic applications includes the steps of preparing a vinylidene olefin by dimerization of an .alpha.-olefin and reacting it with a monomeric silane having a silicon-hydrogen bond in the presence of a metallic catalyst such that the silicon-hydrogen bond is added to the vinylidene double bond of the vinylidene olefin thereby converting the double bond to a single bond and bonding the silicon of the monomeric silane to the vinylidene olefin to form a branched alkylsilane.

Abstract: Silsesquioxane polymers that are useful for preparing SiO.sub.2 -rich ceramic coatings are obtained as the polymeric reaction products from the hydrolysis and condensation of organosilanes having a .beta.-substituted alkyl group. A preferred silsesquioxane polymer is the polymeric reaction product obtained from .beta.-chloroethyltrichlorosilane. Coating compositions containing such silsesquioxane polymers dissolved in organic solvent may be applied to a substrate and converted to SiO.sub.2 -rich ceramic thin layers by evaporating the solvent and heating the coated substrate at moderate temperatures.

Abstract: Novel hydroxymethyltrialkoxysilanes of the formula: ##STR1## are produced by transesterifying a carboxylic acid ester of hydroxymethyltrialkoxysilane with an alcohol, and distilling the reaction mixture to remove the carboxylate of the alcohol. The carboxylic acid ester of hydroxymethyltrialkoxysilane is prepared by the reaction of an alkali metal carboxylate with chloromethyltrialkoxysilane, which in turn is prepared by the reaction of a trialkylorthoester with chloromethyltrichlorosilane by heating to reflux with removal of alkylchloride, followed by distillation to remove alkyl ester. The hydroxymethyltrialkoxysilanes and carboxylic acid esters thereof, as well as carboxymethyltrialkoxysilanes, are particularly useful in sol-gel processing by undergoing hydrolysis to yield hydroxymethylsilanetriol, and subsequent hydrolysis and polycondensation products.

Abstract: Silicone semi-interpenetrating polymer networks are formed in thermoplastic polymer matrices by the vulcanization of a hydride group-containing silicon with a polymer containing unsaturated groups. The semi-IPN is then cross-linked by hydrolysis of SiOR groups on the polymer network, so that the OR groups are hydrolyzed to allow condensation of silanol groups to form SiOSi cross-links between the chains of the polymer network. Preferably, the polymer containing unsaturated groups in an alkoxysilyl-modified poly 1,2-butadiene. The resulting cross-linked products have improved chemical resistance, increased compressive or tensile strength and excellent temperature resistance and electrical properties for use in applications such as paper-making felts and wire and cable insulation.

Abstract: Chromogenic or fluorogenic silanes are formed in which a reactive organosilane is coupled to a chromogenic or fluorogenic nucleus of the coumarin class of compounds, by an ether, urethane or urea linkage. The preferred compounds have the general formula.X.sub.y R'.sub.z Si(CH.sub.2).sub.n L-Couwherein X is a displaceable or hydrolyzable group which allows the silanes to derivatize protic materials; R' is an aliphatic or aromatic hydrocarbon group; L is an ether (O), urethene (NCO) or urea (NCN) linkage; Cou is a coumarin derivative; n=1 to 8; y=1 to 3 and Z=0 to 2, such that y plus z equal 3. The ether linked silanes may be formed by hydrosilylation of an alkenyl ether of the coumarin compound, while the urethane or urea linked silanes may be formed by the direct reaction of a reactive silylisocyanate with a hydroxyl- or amine-substituted coumarin compound. The silanes are useful in derivatizing protic materials to provide the protic materials with chromogenic or fluorogenic properties.

Abstract: Melt processable pseudointerpenetrating polymer networks (pseudo- or semi-IPNs) of silicones in thermoplastic matrices and methods of producing same are provided by vulcanizing the silicones within the matrices. The silicone component of the network is preferably the reaction product of a polymeric hydride group - containing silicone and a polymer containing at least one unsaturated group, preferably a vinyl group. The polymer containing unsaturated groups may be a silicone polymer also, or may be a non-silicone polymer such as a styrene, butadiene or urethane polymer or copolymer. Depending on certain parameters chain-extended (thermoplastic) or cross-linked (thermosetting) compositions are produced.

Abstract: A method of treating a surface to be contacted by a protein-containing fluid reduces protein adsorption to the surface. The method comprises coating or siliconizing the surface with a lower alkyl silane selected from the group consisting of monoalkyl silanes of the formula RSiX.sub.3 wherein R is selected from ethyl and branched (C.sub.3 -C.sub.5) alkyl and X is selected from hydrolyzable groups, such as halogen or lower alkoxy, and dialkyl silanes of the formula R'.sub.2 SiX.sub.2 wherein R' is (C.sub.2 -C.sub.5) alkyl and X is as described above. For example, borosilicate glass vessels for storing blood may be treated.

Abstract: Organosilicon compounds referred to as silacrown ethers or "silacrowns" are of the general formula: ##STR1## where R.sup.1 and R.sup.2 are organic radicals or hydrogen and n is an integer between 4 and 10 inclusive. Silacrown ethers are prepared by reacting polyethylene glycol with substituted silanes under conditions promoting cyclization over polymerization. Silacrown ethers may be employed as phase-transfer catalysts in solution or immobilized on siliceous supports.

Abstract: Linear polysilane-siloxane copolymers having remarkable sensitivity to radiation have the general formula[(SiMe.sub.2).sub.m ].sub.a [(OSiMeR).sub.n ].sub.bwherein Me is a methyl group, R is lower alkyl or phenyl, m=4 to about 30 inclusive, n=1 to about 100 inclusive, a and b may each be 1 to about 10 inclusive, and a units alternate with b units. The copolymers of the invention may be in the form of oligomers, random copolymers where n=1 to 9, block copolymers where n=10 to 100, and mixed (random and block) copolymers. These copolymers may also be in the form of modified copolymers having reactive functional groups such as acrylate, methacrylate, vinyl or other unsaturated substitutions. The copolymers may be produced by formation of a halogen terminated oligomer of a polysilane or polysilane-siloxane copolymer, followed by coupling the oligomers with themselves or with distinct higher molecular weight silanol terminated siloxane species.

Abstract: Modified silacrown ethers are formed having the general formula: ##STR1## wherein R.sup.1 and R.sup.2 are organic radicals, hydrogen or groups which actively assist in the complexing of metal cations, n is an integer between 3 and 10 inclusive, and R.sup.3 is hydrogen or lower alkyl. These modified silacrown ethers are prepared by reacting a polyalkylene glycol with substituted silanes under conditions promoting cyclization over polymerization. The modified silacrown ethers are useful for forming cation complexes and promoting anionic reactions, particularly in phase transfer reactions either in solution or immobilized on siliceous supports.

Abstract: Cyclic silazanes which are particularly useful for the formation of silicon nitrides have the general formula: ##STR1## wherein Me represents methyl (CH.sub.3), n=3-6, x=0-1 and y=0.25-1. These N-methylhydridosilazanes are a convenient source of silicon nitride by chemical vapor deposition to form films for masking layers and dielectric coatings with reduced levels of silicon carbide contamination in the silicon nitride. Low molecular weight, linear polymers of the N-methylhydridosilazanes are also useful in the preparation of silicon nitrides by evaporation from liquid solutions and subsequent pyrolysis and are particularly useful for infiltration of refractories. Particularly preferred compounds of the invention are 2,6 di-N-methyl-1,3,5,7-tetramethylcyclotetrasilazane; 2,4,6,8-tetra-N-methyl-1,5-dimethylcyclotetrasilazane and their polymeric derivatives.

Abstract: Cyclotrisilazanes, including hexamethylcyclotrisilazane, a difunctional blocking agent used to derivatize and protect active hydrogen-containing substrates during chemical analysis and synthetic reactions, may be prepared by heating cyclotetrasilazanes using a Group VIII catalyst in the presence of hydrogen. In addition, the average degree of polymerization of cyclosilazane compositions may be reduced.

Abstract: Optically clear lenses, particularly contact lenses, may be prepared from an alloy of a polyacrylate resin and a siloxane-styrene copolymer, the alloy having an oxygen permeability greater than the polyacrylate resin. Preferably the polyacrylate is polymethylmethacrylate or methylacrylate-ethylacrylate copolymer, and the siloxane-styrene copolymer is preferably a polydimethylsiloxane-alpha-methylstyrene block copolymer. The alloy composition may be produced by melt mixing, preferably by polymerizing acrylate monomers in the presence of siloxane-styrene copolymer.

Abstract: A melt processable pseudointerpenetrating network of silicones in thermoplastic matrices and a method of producing same is provided by vulcanizing the silicones within the matrices. In a preferred embodiment a two part silicone comprising silicon hydride groups and silicon vinyl-containing groups are reacted in the presence of a platinum complex. Depending on certain parameters chain-extended (thermoplastic) or cross-linked (thermosetting) compositions are produced.

Abstract: The preparation of pure mixed alkoxyaminosilanes is described corresponding to the general formula:R.sub.m Si(OR').sub.n (NR"R'").sub.pwherein:R is hydrogen, short chain alkyl or alkenyl or aryl;R" and R'" are separately either hydrogen, short chain alkyl or aryl, at least one being other than hydrogen;R' is short chain alkyl or aryl; andm, n and p are integers such that m+n+p=4 and n and p are at least one each.The obtained compounds are employed in endcapping of polysiloxanes having terminal silane groups.

Abstract: Contact lenses are fabricated from a mixture of polymethymethacrylate and polydimethylsiloxane-bisphenol A carbonate block copolymers. The lenses so produced exhibit excellent oxygen permeability.

Abstract: [2-(p-t-Butylphenyl)ethyl]silanes are provided having the general formula:Si(B).sub.x (R).sub.y (A).sub.zwherein B is a (p-t-butylphenyl)ethyl moiety, R is an alkyl or aryl moiety and A is a hydrolyzeable moiety; x equals 1 or 2, y equals 0, 1 or 2 and z equals 1, 2 or 3 such that x plus y plus z equals 4. The bulky substituted silanes are produced by the hydrosilylation of p-t-butylstyrene.[2-(p-t-Butylphenyl)ethyl] substituted disiloxanes are also provided, having the general formula:(B).sub.x (R).sub.y (A).sub.z Si--O--Si(A).sub.z (R).sub.y (B).sub.xwherein B, R, A, x, y and z are as defined above except that z equals 0,1 or 2 and x plus y plus z equals 3. The bulky substituted disiloxanes are produced by the hydrolysis of above-described bulky substituted silanes.

Abstract: Organosilicon compounds referred to as silacrown ethers or "silacrowns" are of the general formula: ##STR1## where R.sup.1 and R.sup.2 are organic radicals or hydrogen and n is an integer between 4 and 10 inclusive. Silacrown ethers are prepared by reacting polyethylene glycol with substituted silanes under conditions promoting cyclization over polymerization. Silacrown ethers may be employed as phase-transfer catalysts in solution or immobilized on siliceous supports.

Abstract: A melt processable pseudointerpenetrating network of silicones in thermoplastic matrices and a method of producing same is provided by vulcanizing the silicones within the matrices. In a preferred embodiment a two part silicone comprising silicon hydride groups and silicon vinyl-containing groups are reacted in the presence of a platinum complex. Depending on certain parameters chain-extended (thermoplastic) or cross-linked (thermosetting) compositions are produced.