▎ 摘　　要

NOVELTY - Preparation of torsional-resistant low-smoke halogen-free flame retardant cable insulation material involves uniformly mixing 50-200 g styrene-butadiene-styrene block copolymer, 150-400 g styrene-isoprene-styrene block copolymer, 300-420 g magnesium-aluminum layered double hydroxide, 1-5 g graphene oxide and 1-5 g silicone masterbatch in an internal mixer at 130 degrees C, pelletizing mixture, extruding into cable and modifying with crosslinked polymer by electron beam irradiation. USE - The method is useful for preparing torsional-resistant low-smoke halogen-free flame retardant cable insulation material (claimed). ADVANTAGE - The method ensures preparation of low-smoke halogen-free cable insulation material with excellent electrical performance, torsional resistance, aging resistance, oil resistance, heat resistance and flame-retardant property, low toxicity and long service life. DETAILED DESCRIPTION - Preparation of torsional-resistant low-smoke halogen-free flame retardant cable insulation material involves (a) weighing 50-200 g styrene-butadiene-styrene block copolymer, 150-400 g styrene-isoprene-styrene block copolymer, 300-420 g magnesium-aluminum layered double hydroxide, 1-5 g graphene oxide and 1-5 g silicone masterbatch, (b) preparing graphene oxide by adding 5 g phosphorus pentoxide, 24 ml concentrated sulfuric acid and 5 g potassium persulfate to a 1 l three-necked flask, heating at 80 degrees C, stirring mixture until it is completely dissolved, adding 6 g natural graphite, reflux condensation of mixture at 80 degrees C for 4.5 hours, cooling to room temperature, adding 1000 ml deionized water, leaving overnight, washing, drying, adding 240 ml concentrated sulfuric acid to dried graphite in 0 degrees C ice water bath, adding 30 g potassium permanganate, grinding, maintaining the temperature at below 10 degrees C, heating at 35 degrees C, stirring for 2 hours, slowly adding 2 l deionized water to obtain brown suspension, adding 40 ml 30% hydrogen peroxide, stirring to form bright yellow suspension, leaving, adding 300 ml 10% hydrochloric acid to supernatant, settling, washing upper liquid with deionized water and drying, and (c) uniformly mixing above ingredients in an internal mixer at 130 degrees C, pelletizing mixture, extruding into cable and modifying with crosslinked polymer by electron beam irradiation.