摘要:
A method of manufacturing a fiber reinforced silicone foam is described. An aqueous silicone emulsion that cures upon drying at ambient temperature to an elastomeric film is combined with inorganic fibers having a diameter of less than 25 micrometers and a length of less than 10 mm to form a mixture. Air is dispersed through the mixture to form a stable froth. Removing the water from the stable froth yields an open-cell foam having cell walls comprising a thin layer of silicone elastomer reinforced with fibers. If electrically conductive fibers are used, the foam can be electrically conductive.
摘要:
A composition which provides an elastomeric, electrically conductive product upon removal of the water at ambient conditions is described. The composition comprises an emulsion (A) having a dispersed phase of elastomer and a continuous phase of water containing a material selected from the group comprising colloidal silica, alkali metal silicates, and organosilicates, and (B) electrically conductive, metal coated spheres having a diameter of from 5 to 105 micrometers. Because the dispersed particles of elastomer are crosslinked before the metal coated spheres are added, when the water is removed from the emulsion, the metal coated spheres and the dispersed crosslinked elastomer are found in a continuous polar phase. The cured elastomer, having a surface resistivity of less than 2 ohms per square on at least one surface is particularly useful in producing an efficient shield for electromagnetic radiation in the radio and television frequencies.
摘要:
A composition which provides an electrically conductive product upon removal of the water at ambient conditions is described. The composition comprises a dispersed phase of elastomer and a continuous phase of water containing a material selected from the group comprising colloidal silica, alkali metal silicates, and organosilicates. Also present in the continuous phase is greater than 10 parts by weight of electrically conductive particles in the form of fibers having a diameter of less than 25 micrometers and a length of less than 10 millimeters with the ratio of length to diameter of greater than 10:1. Upon drying, the emulsion yields an electrically conductive elastic product having elastomer particles and electrically conductive fibers dispersed in a solid polar continuous phase. The electrically conductive product is particularly useful as an efficient shield for electromagnetic radiation in the radio and television frequencies.
摘要:
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.
摘要:
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.
摘要:
A method for improving properties of a cellulosic textile fabric is disclosed. The fabric is first impregnated with an aqueous emulsion of a carboxyfunctional silicone fluid stabilized by a nonionic surfactant having a particular HLB value, and then heated to crosslink the carboxyfunctional silicone fluid.
摘要:
Condensation products of phenyltrialkoxysilanes (and optionally methyltrialkoxysilanes) and 2-methyl-2,4-pentane diol containing at least 25 percent by weight phenyl radicals are employed as internal lubricants for clear thermoplastics. For example, 1 percent by weight of ##STR1## is added to polystyrene to give an optically clear material having good surface properties.
摘要:
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.
摘要:
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.
摘要:
This disclosure relates to a method for imparting durable press characteristics to textile fabrics containing cellulosic fibers. The fabric is impregnated with a homogeneous composition comprising a volatile liquid carrier and certain methoxylated, phenyl-substituted fluid organosilicon polymers, and is subsequently heated to effect crosslinking of the fluid organosilicon polymers.