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CN-122011562-A - Environment-friendly flame-retardant composite material for cables and preparation method thereof

CN122011562ACN 122011562 ACN122011562 ACN 122011562ACN-122011562-A

Abstract

The invention provides an environment-friendly flame-retardant composite material for cables and a preparation method thereof, wherein the preparation raw materials comprise, by weight, 30-40 parts of an ethylene-1-octene copolymer, 25-35 parts of linear low density polyethylene, 18-25 parts of phosphorus nitrogen silicon aluminum quaternary synergistic hybrid microspheres, 3-6 parts of metal coordination halloysite hybrid carbon nanotubes, 5-8 parts of a reactive compatibilizer, 0.8-1.2 parts of a crosslinking agent, 0.5-1.0 part of a crosslinking assistant agent, 0.4-0.8 part of an antioxidant and 0.5-1.0 part of a lubricant. The invention can improve the flame retardant, char formation, heat conduction and smoke suppression performance of the composite material, optimize the interface compatibility, processing fluidity and heat resistance, enhance the thermal oxygen stability and the anti-dripping performance, and has excellent comprehensive performance.

Inventors

  • WU YANLEI
  • WU CHONGFEI

Assignees

  • 北京市昆仑线缆制造有限公司

Dates

Publication Date
20260512
Application Date
20260306

Claims (8)

  1. 1. The environment-friendly flame-retardant composite material for the cable is characterized by comprising, by weight, 30-40 parts of an ethylene-1-octene copolymer, 25-35 parts of linear low density polyethylene, 18-25 parts of a phosphorus nitrogen silicon aluminum quaternary synergistic hybrid microsphere, 3-6 parts of a metal coordination halloysite hybrid carbon nano tube, 5-8 parts of a reactive compatibilizer, 0.8-1.2 parts of a crosslinking agent, 0.5-1.0 part of a crosslinking assistant agent, 0.4-0.8 part of an antioxidant and 0.5-1.0 part of a lubricant.
  2. 2. The environment-friendly flame-retardant composite material for cables, as claimed in claim 1, wherein the reactive compatibilizer is an ethylene-alkyl acrylate-glycidyl methacrylate terpolymer, the crosslinking agent is dicumyl peroxide, and the auxiliary crosslinking agent is triallyl cyanurate.
  3. 3. The environment-friendly flame-retardant composite material for cables, according to claim 1, is characterized in that the antioxidant is formed by compounding an antioxidant 1010 ‌ and an antioxidant 168 ‌ according to a mass ratio of 1:1.5, and the lubricant is modified ethylene bis stearamide.
  4. 4. The environment-friendly flame-retardant composite material for cables according to claim 1, wherein the preparation method of the phosphorus-nitrogen-silicon-aluminum quaternary synergistic hybrid microsphere comprises the following steps: 1) Mixing tetraethoxysilane and aluminum isopropoxide according to a molar ratio of 1 (0.25-0.35), adding equimolar acetylacetone into the aluminum isopropoxide for chelation, adding absolute ethyl alcohol to prepare a solution with a mass concentration of 18% -22%, dropwise adding 0.1mol/L dilute hydrochloric acid at a temperature of 30-40 ℃ at a concentration of 1-3 mL/min to adjust the pH value to 3.0-4.0, and carrying out hydrolysis activation for 1-2 hours to obtain silicon-aluminum composite sol; 2) Dissolving hexachlorocyclotriphosphazene in anhydrous tetrahydrofuran under the protection of nitrogen, cooling to 0-5 ℃ in an ice bath, keeping stirring at 150-200 r/min, dropwise adding a tetrahydrofuran solution containing p-phenylenediamine at 0.5-2 mL/min, wherein the molar ratio of hexachlorocyclotriphosphazene to p-phenylenediamine is 1 (2.5-3.5), heating to 50-60 ℃ after the dropwise adding is finished, and continuing to react for 5-7 h to obtain an amino-sealed ring triphosphazene prepolymer solution; 3) Adding the amino-terminated triphosphazene prepolymer solution into silicon-aluminum composite sol, adding melamine, and transferring the mixture into a hydrothermal reaction kettle at 80-90 ℃ for reaction for 10-14 h, wherein the molar ratio of melamine to hexachlorocyclotriphosphazene (0.5-1.5): 1; 4) Centrifuging and separating reactants at 6000-8000 r/min, washing the precipitate with absolute ethyl alcohol and deionized water for 3 times respectively, vacuum drying to constant weight under the conditions of 70-90 ℃ and vacuum degree of-0.08 to-0.1 MPa, then heat treating for 1.5-2.5 h under the nitrogen atmosphere of 280-320 ℃, crushing by a jet mill, and controlling the discharge particle size D 50 to be 3-5 mu m to obtain the phosphorus-nitrogen-silicon-aluminum quaternary synergistic hybrid microsphere.
  5. 5. The environment-friendly flame-retardant composite material for cables according to claim 1, wherein the preparation method of the metal coordination halloysite hybrid carbon nanotubes comprises the following steps: (1) Adding absolute ethyl alcohol into a halloysite nanotube, dispersing for 20-40 min under the conditions of ultrasonic power of 200-300W and frequency of 20-40 kHz, adding gamma-aminopropyl triethoxysilane accounting for 14-16% of the weight of the halloysite nanotube, carrying out reflux reaction for 7-9 h at 55-65 ℃, carrying out centrifugal separation at 6000-8000 r/min after the reaction is finished, washing a precipitate with deionized water for 3 times, and carrying out vacuum drying under the conditions of 70-90 ℃ and vacuum degree of-0.08 to-0.1 MPa to obtain an aminated halloysite nanotube; (2) Adding the multiwall carbon nanotube into a mixed solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1, carrying out reflux oxidation for 4-6 hours at 65-75 ℃, cooling, diluting with deionized water, carrying out suction filtration, washing to be neutral, and carrying out vacuum drying at 70-90 ℃ to obtain a carboxylated multiwall carbon nanotube; (3) Adding carboxylated multiwall carbon nanotubes into deionized water, dispersing for 20-40 min under the conditions of ultrasonic power of 200-300W and frequency of 20-40 kHz, adding 8-12% of zinc nitrate hexahydrate, adding an aqueous dispersion of aminated halloysite nanotubes after ultrasonic coordination, continuing ultrasonic treatment for 20-40 min, and freeze-drying for 44-52 h under the conditions of-55 to-45 ℃ and vacuum degree of <10Pa to obtain the metal coordination halloysite hybrid carbon nanotubes.
  6. 6. A method for preparing the environment-friendly flame-retardant composite material for cables according to any one of claims 1 to 5, comprising the following steps: S1, placing an ethylene-1-octene copolymer and linear low density polyethylene in a blast drying oven at 55-65 ℃ for drying for 3-5 hours to obtain a pretreated matrix resin; S2, adding the pretreated matrix resin and a reactive compatibilizer into an internal mixer, mixing for 2-4 min at 110-120 ℃ and rotor rotation speed of 35-55 r/min, adding phosphorus nitrogen silicon aluminum quaternary synergistic hybrid microspheres and metal coordination halloysite hybrid carbon nanotubes, and continuously mixing for 4-8 min at 110-120 ℃ to obtain mixed sizing material; S3, transferring the mixed sizing material into a double-screw extruder with the length-diameter ratio L/D=40:1, adding a cross-linking agent and a crosslinking aid in a lateral feeding mode, adding a composite antioxidant and a lubricant at the same time, extruding, cooling and granulating to obtain the environment-friendly flame-retardant composite material granules for the cable.
  7. 7. The preparation method of the environment-friendly flame-retardant composite material for the cable, which is disclosed in claim 6, is characterized in that in the step S3, the temperatures of each section of the twin-screw extruder are 105-110 ℃, 110-115 ℃ in the first section, 110-115 ℃ in the second section, 110-115 ℃ in the third section, 108-113 ℃ in the fourth section, 110-115 ℃ in the machine head and 70-130 r/min of screw rotation speed, and the cross-linking agent and the auxiliary cross-linking agent are added after the melting section and before the homogenizing section of the extruder.
  8. 8. The preparation method of the environment-friendly flame-retardant composite material for cables, which is characterized in that the octene chain unit content of the ethylene-1-octene copolymer is 18-25wt%, the melt index is 0.5-3.0 g/10min at 190 ℃ per 2.16kg, the weight average molecular weight is 8 multiplied by 10 4 ～12×10 4 g/mol, the melt index is 1.0-2.5 g/10min at 190 ℃ per 2.16kg, and the weight average molecular weight is 7 multiplied by 10 4 ～10×10 4 g/mol.

Description

Environment-friendly flame-retardant composite material for cables and preparation method thereof Technical Field The invention relates to the technical field of high polymer composite materials for cables, in particular to an environment-friendly flame-retardant composite material for cables and a preparation method thereof. Background Polyvinyl chloride (PVC) is convenient to process and moderate in cost, is used as a common insulation and sheath material for wires and cables for a long time, but is easy to release toxic corrosive gases such as hydrogen halide and the like when being burnt, and has obvious limitations on environmental protection and use safety. The crosslinked polyethylene insulated power cable gradually becomes the main stream selection type of medium-high voltage power transmission by virtue of excellent electrical insulation performance, heat resistance and mechanical properties, however, the conventional crosslinked polyethylene material has insufficient flame retardance, char formation and smoke suppression performance, and is difficult to meet the safe use requirement in a severe flame-retardant scene. The application of the current halogen-free flame-retardant polyolefin composite material in the cable field still has obvious short plates, most systems are difficult to simultaneously consider flexibility and structural strength, flame-retardant char formation efficiency is low, smoke release amount is large during combustion, interface combination of inorganic flame-retardant filler and an organic matrix is poor, the heat-resistant deformation, thermal oxygen stability and processability of the material are easy to be reduced, and the preparation and use requirements of the high-performance environment-friendly flame-retardant cable cannot be comprehensively adapted. Disclosure of Invention Aiming at the problems in the prior art, the invention provides an environment-friendly flame-retardant composite material for cables and a preparation method thereof. In order to achieve the above purpose, the invention is realized by the following technical scheme: The invention discloses an environment-friendly flame-retardant composite material for cables, which comprises, by weight, 30-40 parts of an ethylene-1-octene copolymer, 25-35 parts of linear low density polyethylene, 18-25 parts of a phosphorus nitrogen silicon aluminum quaternary synergistic hybrid microsphere, 3-6 parts of a metal coordination halloysite hybrid carbon nanotube, 5-8 parts of a reactive compatibilizer, 0.8-1.2 parts of a crosslinking agent, 0.5-1.0 part of a crosslinking assistant agent, 0.4-0.8 part of an antioxidant and 0.5-1.0 part of a lubricant. Preferably, the reactive compatibilizer is an ethylene-alkyl acrylate-glycidyl methacrylate terpolymer, the crosslinking agent is dicumyl peroxide, and the auxiliary crosslinking agent is triallyl cyanurate. Preferably, the antioxidant is formed by compounding an antioxidant 1010 ‌ and an antioxidant 168 ‌ according to a mass ratio of 1:1.5, and the lubricant is modified ethylene bis stearamide. Preferably, the preparation method of the four-element synergistic hybridization microsphere comprises the following steps: 1) Mixing tetraethoxysilane and aluminum isopropoxide according to a molar ratio of 1 (0.25-0.35), adding equimolar acetylacetone into the aluminum isopropoxide for chelation, adding absolute ethyl alcohol to prepare a solution with a mass concentration of 18% -22%, dropwise adding 0.1mol/L dilute hydrochloric acid at a temperature of 30-40 ℃ at a concentration of 1-3 mL/min to adjust the pH value to 3.0-4.0, and carrying out hydrolysis activation for 1-2 hours to obtain silicon-aluminum composite sol; 2) Dissolving hexachlorocyclotriphosphazene in anhydrous tetrahydrofuran under the protection of nitrogen, cooling to 0-5 ℃ in an ice bath, keeping stirring at 150-200 r/min, dropwise adding a tetrahydrofuran solution containing p-phenylenediamine at 0.5-2 mL/min, wherein the molar ratio of hexachlorocyclotriphosphazene to p-phenylenediamine is 1 (2.5-3.5), heating to 50-60 ℃ after the dropwise adding is finished, and continuing to react for 5-7 h to obtain an amino-sealed ring triphosphazene prepolymer solution; 3) Adding the amino-terminated triphosphazene prepolymer solution into silicon-aluminum composite sol, adding melamine, and transferring the mixture into a hydrothermal reaction kettle at 80-90 ℃ for reaction for 10-14 h, wherein the molar ratio of melamine to hexachlorocyclotriphosphazene (0.5-1.5): 1; 4) Centrifuging and separating reactants at 6000-8000 r/min, washing the precipitate with absolute ethyl alcohol and deionized water for 3 times respectively, vacuum drying to constant weight under the conditions of 70-90 ℃ and vacuum degree of-0.08 to-0.1 MPa, then heat treating for 1.5-2.5 h under the nitrogen atmosphere of 280-320 ℃, crushing by a jet mill, and controlling the discharge particle size D 50 to be 3-5 mu m to obtain the phosphorus-ni