Abstract: The inventive cylindrical cartridges are installed in machinery for purposes of isolating vibration of conventional rolling element bearings from major machinery components. Two inventive cartridges are concentrically coupled with a rolling element bearing, one cartridge fitting circumferentially inside the bearing's inner ring, the other cartridge fitting circumferentially outside the bearing's outer ring. Each inventive cartridge comprises inner and outer concentric cylindrical metallic pieces and an intermediate filling which includes two lateral circumferential elastomeric bands separated by a medial circumferential air gap. The inventive cartridges can be inexpensively fabricated and can be permanently integrated with existing machinery.

Abstract: Fiber-reinforced plastic composite materials are fire-protected by the apcation thereon of a combination of coatings comprising a ceramic coating and an intumescent coating. The ceramic coating consists of zirconia stabilized with yttria.

Abstract: A polyimide and a process for its preparation wherein the polyimide is prepared from reaction of an organic tetracarboxylic acid or derivative thereof with a mixture of an aromatic diamine and an amine-terminated fluoroether. The polyimides of the invention are particularly useful in the preparation of flexible foams.

Abstract: A method of preparing a polyimide foam which includes the steps of: preparing, foaming, and curing a precursor containing at least one alkyl ester of 3,3'4,4'-benzophenonetetracarboxylic acid; a meta- or para-substituted aromatic diamine; a heterocyclic diamine; an aliphatic diamine; and a solid blowing agent. The blowing agent is added to said precursor in a concentration which is sufficient to effect at least one of the following attributes of the foam: cell size, proportion of open cells, cell density, and indentation load deflection.

Abstract: Copolyimide foams derived from a diester of 3,3',4,4'-benzophenonetetracarboxylic acid, an aromatic diamine, and a heterocyclic diamine. A molar concentration of the heterocyclic diamine approaching but not exceeding 0.42 is employed. This results in a flexible foam with a homogeneous cellular structure and a reduced compression set loss.

Abstract: Copolyimide foams derived from a diester of 3,3',4,4'-benzophenonetetracarboxylic acid, an aromatic diamine, and a heterocyclic diamine. A molar concentration of the heterocyclic diamine approaching but not exceeding 0.42 is employed. This results in a flexible foam with a homogeneous cellular structure and a reduced compression set loss.

Abstract: Copolyimide foams derived from a diester of 3,3',4,4'-benzophenonetetracarboxylic acid, an aromatic diamine, and a heterocyclic diamine. A molar concentration of the heterocyclic diamine approaching but not exceeding 0.42 is employed. This results in a flexible foam with a homogeneous cellular structure and a reduced compression set loss.

Abstract: Copolymide foams derived from a diester of 3,3',4,4'-benzophenonetetracarboxylic acid, an aromatic diamine, and a heterocyclic diamine. A molar concentration of the heterocyclic diamine approaching but not exceeding 0.42 is employed. This results in a flexible foam with a homogeneous cellular structure and a reduced compression set loss.

Abstract: Methods of preparing polyimides and polyimide precursors from liquid resins containing tetracarboxylic acid esters and primary diamines which involve spray drying the resin.

Abstract: A composite structure having a substrate is protectively covered during fabrication by a barrier layer, such as an intumescent mat or felt, into which a fire resisting agent such as phenolic resin or water, or oil based intumescent coating is infused in-situ before attachment to the substrate and completion of composite structure fabrication. The barrier layer is infused in-situ with the phenolic resin before attachment by adhesive bonding to the substrate or infusion is performed during formation of the underlying substrate layer so as to achieve attachment without adhesive.