Abstract: A composition of matter is provided, including anhydrite calcium sulfate whiskers having a mean aspect ratio of at least 30. Another composition of matter is provided, including alpha-derived anhydrite calcium sulfate whiskers. Yet another composition of matter is provided, including fine alpha particle-derived anhydrite calcium sulfate whiskers.

Abstract: Gypsum composites containing cementitious materials and methods of making the same are provided. Gypsum composites include gypsum and a cementitious material. Methods of making gypsum composites include combining gypsum stucco, water, and a cementitious material to form a slurry, and setting and drying the slurry to form a gypsum composite.

Abstract: Building materials include a dampening layer which contains a plaster and a viscoelastic polymer, such as polyvinyl butyral. The dampening layer may also include a barium salt. Methods of making a sound dampening material include providing a plaster mixture. The mixture may include a viscoelastic polymer and/or a barium salt. The plaster mixture is combined with water and/or a viscoelastic polymer dispersion, to form a slurry. The slurry is applied to a surface and set to form a sound dampening layer.

Abstract: Methods of making calcium sulfate whiskers are provided. In one aspect, a method includes autoclaving a slurry of calcium sulfate hemihydrate and water to form calcium sulfate hemihydrate whiskers in water and microwaving the whiskers to dewater them, wherein the microwaving is effective to prevent a majority of the whiskers from reverting to a dihydrate form. In one aspect, a method includes microwaving calcium sulfate hemihydrate whiskers to form anhydrite calcium sulfate whiskers, wherein the microwaving is effective to remove a substantial amount of chemically bound water from the whiskers.

Abstract: A composition of matter is provided, including anhydrite calcium sulfate whiskers having a mean aspect ratio of at least 30. Another composition of matter is provided, including alpha-derived anhydrite calcium sulfate whiskers. Yet another composition of matter is provided, including fine alpha particle-derived anhydrite calcium sulfate whiskers.

Abstract: Gypsum composites containing cementitious materials and methods of making the same are provided. Gypsum composites include gypsum and a cementitious material. Methods of making gypsum composites include combining gypsum stucco, water, and a cementitious material to form a slurry, and setting and drying the slurry to form a gypsum composite.

Abstract: Methods for making composite products and methods for their use and manufacture are provided. In at least one specific embodiment, alpha-derived anhydrite calcium sulfate whiskers and a plastic can be combined to produce a composite product.

Abstract: Anhydrite calcium sulfate whiskers are prepared by combining alpha calcium sulfate hemihydrate and water to form a slurry, autoclaving the slurry to form alpha calcium sulfate hemihydrate whiskers in water, dewatering the alpha calcium sulfate hemihydrate whiskers, and heating the alpha calcium sulfate hemihydrate whiskers to form anhydrite calcium sulfate whiskers. A composite includes alpha-derived anhydrite calcium sulfate whiskers and a base material and is prepared by combining alpha-derived anhydrite calcium sulfate whiskers with a base material to form a composite.

Abstract: Building materials include a dampening layer which contains a plaster and a viscoelastic polymer, such as polyvinyl butyral. The dampening layer may also include a barium salt. Methods of making a sound dampening material include providing a plaster mixture. The mixture may include a viscoelastic polymer and/or a barium salt. The plaster mixture is combined with water and/or a viscoelastic polymer dispersion, to form a slurry. The slurry is applied to a surface and set to form a sound dampening layer.

Abstract: The present invention is directed to a primer for application to a rubber gasket for its subsequent repair by a room temperature-curable elastomer. The primer comprises masticated rubber, liquid natural rubber, and carbon black dispersed in a solvent therefor. The method for preparing the rubber gasket surface for repair by a room-temperature-curable elastomer by priming the surface with the inventive primer forms another aspect of the present invention. The rubber gasket which has been primed with the inventive primer forms a further aspect of the present invention.