▎ 摘　　要

NOVELTY - Producing (M1) an electrically-conductive polyurethane foam, comprises: forming a reaction mixture comprising (a) component A comprising an isocyanate, (b) component B comprising at least one polyol, (c) a dispersion of exfoliated graphene nanoplatelets, and (d) a blowing agent; and curing the reaction mixture to provide a three-dimensional composite structure which comprises a direct current electrical conductivity configured to conduct a provided current from an impressed-current cathodic protection system as required by Federal law to be utilized on underground metallic oil and gas pipeline facilities. USE - The methods are useful for: producing an electrically-conductive polyurethane foam; and mitigating or preventing corrosion of external metallic pipe surface. ADVANTAGE - The methods: utilize carbon nanomaterials that provide thermal and electrical conductivity properties; utilize grapheme that have high aspect ratio, high surface area, favorable mechanical attributes, thermal conductivity, electrical conductivity, flexibility and gas barrier qualities as well; and provide polyurethane foam that reduced labor costs, reduced risk of employee injury (and even death) versus use of sandbags, and increased productivity resulting from much faster job site completion. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) mitigating or preventing (M2) corrosion of an external metallic pipe surface beneath a cured formation of polyurethane foam applied on and/or around a buried metallic pipeline structure surrounded by an electrolyte predominantly comprising moisture-rich soil utilizing an impressed-current cathodic protection system, comprising (1) forming the reaction mixture and (2) providing the reaction mixture in a form compatible with customary operation of plural-component, impingement-mix air spray gun equipment and mixer configurations, and (3) performing high-pressure spray application of the reaction mixture to combine components A and B and provide curing of electrically-conductive compositions of polyurethane foam directly on and/or around the buried pipeline structure in place, and (4) providing operation of an impressed-current cathodic protection electrical circuit or system comprising an above-ground DC power source or rectifier unit which is electrically connected to at least one underground anode deployed within the electrolyte surrounding the buried pipes with applied foam to be protected against external corrosion, where the cathodic protection electrical circuit and the electrolyte provide current flow via positive DC power supply within the rectifier unit through each provided electrically-conductive composition of foam and to at least one metallic pipe if an exposed metallic pipe area is present, the current flow which occurs between an exposed metallic pipe area and the electrolyte producing negative electrical potentials at the surface of each exposed metallic pipe area, and this current flow occurs as the provided electrical current(s) complete at least one return path on the negative side of the cathodic protection circuit back to the rectifier unit; and (2) a buried metallic pipeline structure comprising successive installations of cured compositions of electrically-conductive polyurethane foam comprising graphene nanoplatelets, where the support and protection of the buried structure is provided by the installations of cured foam and corrosion of the metallic pipeline beneath the successive installations of the cured foam is mitigated or prevented by the installed electrically-conductive foam compositions, and the successive installations of the foam comprise a direct current electrical conductivity compatible with conducting a provided current from an impressed-current cathodic protection system as required by Federal law to be utilized on buried metallic oil and gas pipeline structures.