Abstract: Improved acoustic damping materials comprise interpenetrating polymer netks having a soft polymer component and a hard polymer component. The soft polymer component, constituting from 50 to 90 percent by weight of the material, is a polyurethane made by polymerization of a diisocyanate with a polyether glycol, and the hard polymer component is made by polymerization of bisphenol A diglycidyl ether, with boron trichloride amine complex as a curing agent.

Abstract: Improved acoustic damping materials comprise interpenetrating polymer netks having a soft polymer component and a hard polymer component. The soft polymer component, constituting from 75 to 95, preferably 90, percent by weight of the material, is made by polymerizing an aromatic diisocyanate with a polyalkylene ether glycol, and the hard polymer component is a vinyl ester polymer made by polymerization of the acrylate or methacrylate ester of the diglycidyl ether of a polyphenol. The curing of the mixture is carried out at room temperature in presence of a peroxide and an aromatic amine. The mixture of ingredients, while liquid, may be injected into mechanical devices, such as shafts of rotating equipment whose noise is to be dampened, and allowed to cure therein.

Abstract: Improved acoustic damping materials comprise interpenetrating polymer netks having a soft polymer component and a hard polymer component. The soft polymer component, constituting from 50 to 90, preferably 70, percent by weight of the material, is made by polymerizing an aromatic diisocyanate with a polyalkylene ether glycol, and the hard polymer component is a vinyl ester polymer made by polymerization of a vinyl ester resin such as the acrylate or methacrylate ester of the diglycidyl ether of a polyphenol. Optionally, the vinyl ester resin may be brominated, whereby increased fire retardance is conferred upon the interpenetrating polymer network. The mixture is cured at room temperature.

Abstract: This invention relates to polymeric materials formable by casting at room mperature and having antifouling material incorporated therein. It is the reaction product of a) with polyether polyols and methylene bis (4-cyclohexyl) isocyanate, where a) is a polymer composition which is the reaction product of the distilled tributyltin oxide with a copolymer of either methyl methacrylate or methyl acrylate and, with either methacrylic acid or acrylic acid in such proportion that four (4) percent of the carbonyl groups remain unreacted.

Abstract: Objects which are designed to be submerged in a marine environment are prcted from fouling for an extended period of time by the use of elastomeric based covering materials which are characterized by a constant delivery rate of the incorporated organometallic polymer toxicant from the formulation.