Abstract: A method for forming blends of polydiorganosiloxanes and solid, sulfonated polyolefins and novel blends prepared by the method. In the present method the solid, sulfonated polyolefin is swollen with a diorganosiloxane oligomer whose rearrangement to high molecular weight polydiorganosiloxanes is catalyzed in situ by the sulfonic acid substituents of the polyolefin.

Abstract: A process for the rearrangement of polyorganosiloxanes using solid sulfonated polyethylene as a rearrangement catalyst. The process comprises contacting polyorganosiloxanes at a temperature within a range of about 20.degree. C. to 110.degree. C. with a rearrangement catalyst consisting essentially of a solid sulfonated polyethylene. In a preferred process, the solid sulfonated polyethylene is in the form of hollow fibers through which the polyorganosiloxanes are passed to effect rearrangement.

Abstract: A method for stabilizing a mixture comprising polydiorganosiloxane and an alkali metal. The method comprises contacting a silyl phosphonate described by formula R.sup.1.sub.a (OH).sub.b (OSiR.sup.2.sub.3).sub.3-a-b P.dbd.O, where each R.sup.1 and R.sup.2 is an independently selected hydrocarbyl radical comprising less than about twelve carbon atoms, a=1 or 2, b=0 or 1, and a+b=1 or 2, with a polydiorganosiloxane and an alkali metal.

Abstract: Coatings of hydrophilic organic polymers such as polyvinyl alcohol are grafted to substrates formed from hydrophobic organic polymers and polyorganosiloxanes by exposing the surface of the substrate to an aqueous solution of the hydrophilic poller in the presence of a solubilized compound of tetravalent cerium that preferably contains hydroxyl or amino groups as ligands.

Abstract: This invention provides reinforced composite structures consisting essentially of a matrix and a dispersed phase, where the matrix is a hydrogel containing water and a solubilized vinyl alcohol homopolymer, the dispersed phase contains a plurality of uniformly distributed acicular regions consisting of fibrils formed from a highly oriented crystalline vinyl alcohol polymer, where the diameter of the said fibrils is less than 1 millimeter, the aspect ratio of the fibrils is from 2:1 to 1000:1, and where the composite is characterized by a gradual transition in the degree of crystallinity at the interfaces between the matrix and the fibrils.

Abstract: This invention provides reinforced composite structures consisting essentially of a matrix and a dispersed phase, where the matrix is a hydrogel containing water and a solubilized vinyl alcohol homopolymer, the dispersed phase contains a plurality of uniformly distributed acicular regions consisting of fibrils formed from a highly oriented crystalline vinyl alcohol polymer, where the diameter of the said fibrils is less than 1 millimeter, the aspect ratio of the fibrils is from 2:1 to 1000:1, and where the composite is characterized by a gradual transition in the degree of crystallinity at the interfaces between the matrix and the fibrils.

Abstract: This invention relates to hollow elongate articles such as tubing and fibers formed from non-crosslinked polyvinyl alcohol. The articles are prepared by extruding a solution of polyvinyl alcohol in the shape of the desired article into a coagulating bath concurrently with a stream of a non-solvent for the polymer. The stream occupies the area corresponding to the interior cavity of the article and prevents collapse of the cavity until the article has solidified in the coagulation bath.

Abstract: A process is provided for the preparation of expanding-contracting hydrogel composites which process comprises the steps of adding solid particles of a polyelectrolyte to a polyvinyl alcohol solution and subjecting the mixture to a low temperature treatment to cause gelation of the polyvinyl alcohol with the polyelectrolyte dispersed as a heterogeneous phase (i.e. solid particles) within the polyvinyl alcohol gel. Hydrogel composites made by the process exhibit high strength and a capacity to expand and contract over a wide range with changes in environment.

Abstract: A curable polydiorganosiloxane is reinforced by mixing with a solution of polyvinylalcohol (PVA) or a modified PVA. The polydiorganosiloxane is then cured and the solvent is extracted to yield a cured polydiorganosiloxane reinforced with PVA.

Abstract: A curable polydiorganosiloxane is reinforced by mixing with a modified polyvinylalcohol (PVA). Fully hydrolyzed PVA is modified by dissolving or swelling in solvent, then adding a silylating agent of the formula R".sub.b (R'.sub.2 SiO).sub.n SiR.sub.a X.sub.4-a where R is a group capable of undergoing hydrolysis to form a siloxane bond with the curable polydiorganosiloxane, R' is a monovalent alkyl or aryl radical having from 1 to 6 carbon atoms, optionally halogen substituted, and compatible with the curable polydiorganosiloxane, R" is either R or R', X is a radical reactive with the hydroxyl on the PVA, a and b are integers of 0 to 3 inclusive, the sum of a plus b is from 1 to 3 inclusive, and n is from 0 to 35. This modified PVA is then mixed with the curable polydiorganosiloxane. The polydiorganosiloxane is then cured and the solvent is extracted to yield a cured polydiorganosiloxane reinforced with polyvinylalcohol.

Abstract: A fine powder is obtained by first dissolving polyvinylalcohol and tetraalkoxysilicate in a common solvent to obtain a reaction product, then spraying a fine mist of a solution of the reaction product into a coagulating bath of a solvent which is miscible with the common solvent, but a poor solvent for the reaction product. After drying, the fine particles obtained are useful as filler in polydiorganosiloxane compositions.

Abstract: A novel method for making stable aqueous microemulsions of high molecular weight polydiorganosiloxanes which comprises sequentially adding at an effective rate a standard emulsion comprised of polydiorganosiloxane precursor, surfactant, and water to a polymerization catalyst medium while mixing to form a clear, stable aqueous microemulsion of polydiorganosiloxane.

Abstract: Aesthetically attractive, free standing dispensers for the controlled release of volatile liquid materials such as perfumes and fragrances into the atmosphere are prepared by (1) forming a first solution by heating a mixture comprising polyvinyl alcohol and water and/or dimethyl sulfoxide under atmospheric pressure, (2) adding a second solution comprising a volatile liquid material and a monohydric alcohol in a solvent that is miscible with the first solution under conditions that avoid precipitation of polyvinyl alcohol, and then (3) cooling the resultant solution to below room temperature to form a gel in the shape of the final dispenser. The exterior surfaces of the dispenser remainds dry to the touch throughout its useful life.

Abstract: Aesthetically attractive, free standing dispensers for the controlled release of volatile liquid materials such as perfumes and fragrances into the atmosphere consist essentially of composite hydrogels comprising a continuous phase of a solubilized polyvinyl alcohol, a dispersed phase comprising a polyelectrolyte and an aqueous solution of the volatile liquid that is distributed between said continuous and dispersed phases. The exterior surfaces of the dispenser remain dry to the touch throughout its useful life.

Abstract: Aesthetically attractive, free standing dispensers for the controlled release of volatile liquid materials such as perfumes and fragrances into the atmosphere consist essentially of composite hydrogels comprising a continuous phase of a solubilized polyvinyl alcohol, a dispersed phase comprising a polyelectrolyte and an aqueous solution of the volatile liquid that is distributed between said continuous and dispersed phases. The exterior surfaces of the dispenser remain dry to the touch throughout its useful life.

Abstract: Solutions of polyvinyl alcohol in non-aqueous mixtures of dimethyl sulfoxide and up to about 30 weight percent, based on said mixture, of an alcohol containing from 1 to about 4 carbon atoms can be converted to hydrogels, fibers and other useful products.

Abstract: A polydiorganosiloxane emulsion having a combination of high polymer content and low viscosity can be produced by blending a high polymer content polydiorganosiloxane macroemulsion, having a polymer content of greater than 60 percent by weight and an average particle size of greater than 0.14 micrometers, and a high polymer content polydiorganosiloxane microemulsion, having a polymer content of from 20 to 30 percent by weight and an average particle size of less than 0.14 micrometers, with the ratio of the average particle size of the macroemulsion to the average size of the microemulsion of from 5 to 15.

Abstract: A curable, reinforced polydiorganosiloxane microemulsion is prepared by adding from 5 to 30 parts by weight of colloidal silica per 100 parts by weight of polydiorganosiloxane in the microemulsion and from 1 to 5 parts by weight of dialkyltindicarboxylate catalyst per 100 parts by weight of the microemulsion to polydiorganosiloxane microemulsion. The curable, reinforced polydiorganosiloxane emulsion can be cast into coherent, elastomeric films of less than 0.4 micrometer thickness.

Abstract: A method of improving the adhesion of silicone elastomers, obtained from aqueous emulsions, comprises mixing the emulsion with an amine functional co-oligomer. A preferred co-oligomer is of the formula ##STR1## where R is a monovalent alkyl radical of from 1 to 6 carbon atoms, x is from 1 to 250, and y is from 2 to 50.

Abstract: The shelf life of an aqueous, anionic silicone emulsion, which contains an organic tin compound and which forms an elastomer upon removal of the water, is improved by the addition of an additive. The additive is selected from the group consisting of alkyl mercaptan, 8-quinolinol, thioglycolic acid, and salts of thioglycolic acid. Elastomers produced by removing the water from these emulsions, once shelf aged, have more consistent physical properties than do elastomers produced from similar emulsions not containing the additives.