Abstract: There is disclosed a sound-absorbing syntactic foam comprising expanded polystyrene microspheres, dispersed randomly in a polyurethane matrix.

Abstract: An assembly for protecting a conduit having a core and an axial length, which length is susceptible to being pinched by a structure is disclosed. The conduit includes an insulating coating in surrounding relationship about the core, with the assembly including a semiconductive layer in surrounding relationship about the insulating coating, and a switching layer in surrounding relationship about the semiconductive layer. The semiconductive layer being formed from partially vulcanized ethylene propylene rubber including particles of a conductive element in the form of carbon black, silver, nickel, aluminum or the like. The switching layer is non-conductive in its unstressed state and conductive when pinched such that the switching layer completes a current flow path between the semiconductive layer and either a grounded structure or another conductive layer, which condition may then be detected.

Abstract: An acoustic foam composition comprising (a) about 1 equivalent of a polybutadiene based polyol (b) about 2.5 to 7.5 equivalents of a diisocyante (c) or low molecular weight diol which gives a balanced stoichiometry and (d) about 1.5 to 6% by weight based on the total weight of the composition of hollow polymeric microspheres. The composition may be prepared by a one-step system or a prepolymer system. The foam compositions of the present invention has excellent acoustic properties.

Abstract: A resilient polyurethane elastomeric article is made from (A) a prepolymer prepared from a composition consisting essentially of diphenylmethane diisocyanate and polyoxytetramethylene glycol, and (B) a dual component chain extender consisting essentially of a low molecular weight triol and a material selected form one of 1,4-butanediol and resorcinol di-(beta-hydroxy ethyl) ether. The admixture can be used to impregnate or coat porous fabric material which upon cure and be used as relatively soft, flexible seals or shock isolator pads.

Abstract: A resilient polyurethane elastomer structural member is made from (A) a prepolymer prepared from a composition consisting essentially of 2.60 moles to 2.80 moles of 4,4'-diphenylmethane diisocyanate, and about 0.23 mole to about 0.31 mole of a low molecular weight triol, per 1.0 mole of polyoxytetramethylene glycol, and (B) hydroquinone di-(.beta.-hydroxyethyl) ether, as a chain extender. This polyurethane elastomer can be used to make annular missile shock isolator pads useful for the land based, MX (Peacekeeper) missile.

Abstract: A resilient, strong, high modulus polyurethane elastomer structural member is made from (A) a prepolymer prepared from a composition consisting essentially of 4,4'-diphenylmethane diisocyanate, low molecular weight triol, and polyoxytetramethylene glycol, and (B) hydroquinone di-(.beta.-hydroxyethyl) ether, as a chain extender.

Abstract: A compatible, gellable, dual resin system useful for impregnating porous spacers between stator end windings of turbine generators is made from (A) a liquid diallyl isophthalate component comprising an admixture of liquid diallyl isophthalate monomer and solid diallyl isophthalate prepolymer, where the weight ratio of monomer:prepolymer is between about 1.5:1 and about 3.0:1, (B) an amount of chain forming isocyanate terminated polyurethane prepolymer effective to provide a chain network which physically interpenetrates the liquid diallyl isophthalate component, and prevents free flow of liquid diallyl isophthalate component, (C) a chain extender for the isocyanate terminated polyurethane prepolymer, and (D) a catalyst for the diallyl isophthalate component, where the resin system is curable with the application of heat.