▎ 摘　　要

NOVELTY - Producing flame-retardant power cord comprises fixing stranding element around wrapping tape, stranding element, and then applying flame-retardant layer, where e.g. flame retardant layer is composed of aqueous polyurethane flame retardant resin, nano graphene, vinyl acetate, liquid paraffin, epoxy soybean oil, dioctyl terephthalate, rare earth nitrate and coupling agent; preparation method of aqueous polyurethane flame retardant resin comprises e.g. mixing poly (tetramethylene ether) glycol-200, polyoxypropylene glycol and poly (propylene adipic acid) and drying in a hot air. USE - The method is useful for producing flame-retardant power cord. ADVANTAGE - The power cord has excellent mechanical and electrical properties, improved flame retardant performance, thermal conductivity and heat dissipation. DETAILED DESCRIPTION - Producing flame-retardant power cord comprises fixing stranding element around wrapping tape, stranding element, and then applying flame-retardant layer, where flame retardant layer is composed of 60-70 pts. wt. aqueous polyurethane flame retardant resin, 1.5-1.8 pts. wt. nano graphene, 8-10 pts. wt. vinyl acetate, 50-60 pts. wt. calcium powder and 4-5 pts. wt. heat stabilizer, 0.5-1 pts. wt. liquid paraffin, 0.2-0.5 pts. wt. epoxy soybean oil, 45-50 pts. wt. dioctyl terephthalate, 2-4 pts. wt. rare earth nitrate and 1-1.5 pts. wt. coupling agent, where preparation method of aqueous polyurethane flame retardant resin comprises (i) mixing 100-200 pts. wt. poly (tetramethylene ether) glycol-200, 5-8 pts. wt. polyoxypropylene glycol and 10-12 pts. wt. poly (propylene adipic acid) and drying in a hot air to a moisture content of below 3%, performing vacuum dehydration at vacuum degree of 0.03-0.06 MPa to moisture content of less than 0.1% to obtain material A, (ii) mixing material A, hydrogenated diphenylmethane diisocyanate, tetramethylcyclohexyl diisocyanate, polyether and polycaprolactone in a mass ratio of 100-120:3:5:5:0.1 in a reaction kettle, heating at 80-85 degrees C, incubating for 40-45 minutes, adding 1 times the mass of polycaprolactone catalyst, reacting and stirring for 100 revolution/minutes, (iii) detecting the reactor isocyanate content, when isocyanate content reaches the theoretical value, adding 15 times the polycaprolactone mass fraction of dimethylethanolamine to continue the reaction for 12-18 minutes to obtain prepolymer, and (iv) adding prepolymer and deionized water into the tank, performing chain extension reaction, removing acetone, and stirring.