Abstract: A process is disclosed for producing polyamide 66 polymers from at least one circular atom component. The circular atom component, for instance, can comprise a fluid obtained from biomass or from an industrial waste stream, such as an industrial gas stream that would otherwise be released to the environment. Polyamide 66 polymers are produced not only containing large amounts of circular atoms but also with excellent mechanical and physical properties.

Abstract: Novel methods for circulation of refrigerants within closed loop systems and using flexible hoses are disclosed that are capable of handling high pressure fluids and providing high barrier against permeation loss. The hoses comprise (from innermost to outermost layer) a thermoplastic veneer; a tie layer; a metal-polymer laminate; a braid under-layer of a thermoplastic or thermosetting elastomer; a reinforcing braid layer; and an outer layer of an elastomeric material.

Abstract: Polymeric pipes with barrier layers are made by attaching to a pipe a multilayer structure which comprises a barrier layer and at least one irregularly surfaced sheet. The resulting pipes, which have reduced permeation to various substances, are useful for reducing loss of materials which are valuable, toxic and/or environmentally harmful.

Abstract: Novel flexible hoses are disclosed that are capable of handling high pressure fluids and providing high barrier against permeation loss. The hoses comprise (from innermost to outermost layer) a thermoplastic veneer; a tie layer; a metal-polymer laminate; a braid under-layer of a thermoplastic or thermosetting elastomer; a reinforcing braid layer; and an outer layer of an elastomeric material. The hoses are suitable for use in air conditioning, refrigeration, fuel handling, hydraulic and similar systems requiring the transport of high pressure fluids.

Abstract: Plastic tube-type heat exchanger structures are made with partially crystallized partially aromatic polyamides of high glass transition temperature. The structures are then annealed to further crystallize the polyamides, causing shrinkage and building up residual tensile stresses. These stresses counteract the swelling caused by water absorption and temperature rise during use of the heat exchanger and keep the structures dimensionally stable.

Abstract: A method and apparatus for making multi-layered plastic tube reinforced with fibers by a co-extrusion process. The method and apparatus provide more specifically a multi-layered plastic tube with an intermediate layer thereof having discrete fibers where at least a major portion of the fibers is oriented to extend predominantly in a general direction lying between the circumferential and the longitudinal axis of the tube with the orientation of the fibers being generally the same throughout the thickness of the intermediate layer.