USA As Represented by Secretary of the Navy

William L Yeager

Timothy L Dapp

Usman A Sorathia

Vincent J Castelli

William B Mercer

Alexander Lebovits

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.

Polyurethane-epoxy interpenetrating polymer network acoustic damping

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.

Interpenetrating polymer network acoustic damping material

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.

Anti-fouling castable polymers and anti-fouling polyurethanes and

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. The formulation consists essentially of, by weight, from about 44% to about 85% of elastomeric material selected from the group consisting of neoprene (polychloroprene) rubber, natural rubber, and EPD (ethylene-propylene-diene) rubber; from about 7% to about 25% of selected fillers, antioxidants, accelerators, pigments, and other processing compounds, and; from about 1% to about 48% of organometallic polymer containing pendant group tri-n-butyltin selected from the group consisting of poly (tri-n-butyltin methyacrylate-co-tri-n-propyltin methyacrylate-co-methyl methacrylate 1:1:1 mole ratio, poly (tri-n-butyltin methacrylate-co-methyl methacrylate) 1:1 mole ratio, tri-n-butyltin ester of poly (methyl vinyl ether-co-maleic acid) 1:1 mole ratio and tri-n-butyltin ester of poly methacrylic acid cross-lined with divinylbenzene.

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Queen Anne, MD, United States of America

William L Yeager