Temperature-responsive flame-retardant composite material as well as preparation method and application thereof

Abstract

The invention relates to a temperature-responsive flame-retardant composite material as well as a preparation method and application thereof, and belongs to the technical field of compositions of high-molecular compounds. The temperature-responsive flame-retardant composite material is prepared from the following components in parts by weight: 40 to 80 parts of matrix resin, 15 to 75 parts of modified flame-retardant filler and 3 to 15 parts of flame-retardant synergist, the modified flame-retardant filler comprises an inorganic flame-retardant filler and a coating layer arranged on at least part of the surface of the inorganic flame-retardant filler, and the coating layer comprises an LCST type temperature-responsive high-molecular polymer. The temperature-responsive flame-retardant composite material has good flame retardant property and excellent mechanical property.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer compound compositions, and in particular to a temperature-responsive flame-retardant composite material and a preparation method and application thereof. Background Art

[0002] The flame retardant properties of cable sheaths have an important impact on the safety of power systems. Although traditional halogen flame retardants have high flame retardant efficiency, they produce a large amount of toxic smoke and corrosive gases when burned. Compared with halogen flame retardants, halogen-free flame retardants not only do not release toxic gases such as hydrogen halides (such as HCl, HBr) and dioxins when burned, but the smoke produced by combustion is also significantly lower than that of halogen flame retardants. Among them, inorganic metal hydroxide flame retardants are the most widely used halogen-free flame retardants, but because they mainly rely on their own decomposition to degrade combustion heat and dilute oxygen at the same time, their content in composite materials often needs to exceed 50% to ensure a good flame retardant effect. However, the polarity of inorganic metal hydroxides is relatively high, resulting in poor compatibility with the resin matrix of the cable sheath, which in turn makes the mechanical properties of the cable sheath poor. Therefore, it is necessary to develop a cable sheath material that has both good flame retardancy and excellent mechanical properties. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a temperature-responsive flame-retardant composite material and a preparation method and application thereof.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a temperature-responsive flame-retardant composite material comprising the following components in parts by weight: 40 to 80 parts of a base resin, 15 to 75 parts of a modified flame-retardant filler, and 3 to 15 parts of a flame-retardant synergist;

[0006] The modified flame retardant filler comprises an inorganic flame retardant filler and a coating layer provided on at least a portion of the surface of the inorganic flame retardant filler, wherein the coating layer comprises an LCST type temperature responsive high molecular polymer.

[0007] The present invention utilizes a coating layer comprising an LCST-type temperature-responsive polymer to surface-modify an inorganic flame-retardant filler. This not only adjusts the surface polarity of the inorganic flame-retardant filler but also effectively prevents agglomeration of the inorganic flame-retardant filler, thereby improving the uniformity of its dispersion within the matrix resin. Furthermore, the coating layer comprising the LCST-type temperature-responsive polymer forms a flexible interface layer between the inorganic filler and the matrix resin to evenly distribute stress. Furthermore, the coating layer is capable of interpenetrating or entangled with the molecular chains of the matrix resin during melt blending, thereby effectively improving the mechanical properties of the flame-retardant composite material. Furthermore, the high temperature generated during combustion of the flame-retardant composite material causes the LCST-type temperature-responsive polymer in the coating layer to shrink, exposing the inorganic flame-retardant filler. This provides more flame-retardant active sites, which, in conjunction with the flame-retardant synergist, promote the formation of a dense carbon layer, achieving a triple synergistic flame retardancy of "physical barrier, chemical smoke suppression, and free radical quenching," thereby significantly improving the flame-retardant properties of the temperature-responsive flame-retardant composite material.

[0008] Optionally, the weight proportion of the matrix resin in the temperature-responsive flame-retardant composite material can be any one of 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, and 80 parts, or any two of the range values; the weight proportion of the modified flame-retardant filler can be any one of 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, and 75 parts, or any two of the range values; the weight proportion of the flame retardant synergist can be any one of 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, and 15 parts, or any two of the range values.

[0009] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the mass percentage of the coating layer is 0.5% to 10% (for example, it can be any one or two of 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%) based on the mass of the modified flame-retardant filler. By regulating the mass percentage of the coating layer in the modified flame-retardant filler within the above range, not only can the interfacial bonding performance between the inorganic flame-retardant filler and the matrix resin be significantly improved, but the LCST-type temperature-responsive polymer in the coating layer on the surface of the inorganic filler can also be caused to shrink rapidly when the temperature-responsive flame-retardant composite material is formed, thereby exposing a large number of flame-retardant active sites, thereby significantly improving the flame retardant properties of the temperature-responsive flame-retardant composite material in a short period of time.

[0010] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the particle size D of the inorganic flame-retardant filler is 50The particle size D of the inorganic flame retardant filler is 10 nm to 10 μm (for example, it can be any one of 10 nm, 50 nm, 100 nm, 200 nm, 300 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, and 10 μm, or any two of the range values). 50 Within the above range, the temperature-responsive flame-retardant composite material can better balance flame-retardant properties and mechanical properties.

[0011] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the modified flame-retardant filler is obtained by atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization of an inorganic flame-retardant filler, a temperature-responsive monomer, and a cross-linking agent;

[0012] The temperature-responsive monomer includes at least one of N-isopropylacrylamide, N-vinylcaprolactam, N,N-diethylacrylamide, N-vinylformamide, vinyl methyl ether, ethylene oxide, and ethylene glycol; and the cross-linking agent includes at least one of di[2-(methacryloyloxy)ethyl]phosphate and N,N'-methylenebisacrylamide.

[0013] Preferably, the mass ratio of the above-mentioned inorganic flame retardant filler, temperature responsive monomer and cross-linking agent can be 50: (2-4): 0.5, specifically it can be any one of 50:2:0.5, 50:2.2:0.5, 50:2.4:0.5, 50:2.6:0.5, 50:2.8:0.5, 50:3:0.5, 50:3.2:0.5, 50:3.4:0.5, 50:3.6:0.5, 50:3.8:0.5, 50:4:0.5 or any two of the range values.

[0014] For example, the modified flame retardant filler can be prepared by the following preparation method:

[0015] S1. Evenly mix an inorganic flame retardant filler, a surfactant (for example, at least one of sodium dodecylbenzenesulfonate, sodium α-olefinsulfonate, sodium lauryl sulfate, cetyltrimethylammonium bromide, fatty alcohol polyoxyethylene ether, and cocamidopropyl betaine) and water (preferably deionized water);

[0016] S2. In an inert gas atmosphere (such as nitrogen, argon, etc.), continue to add the temperature-responsive monomer and the cross-linking agent and mix them evenly at 60-80°C (for example, heating under reflux and stirring for 10-70 minutes at a stirring speed of 100-600 rpm), then add the initiator and react for 1-24 hours, centrifuge, filter, and dry to obtain a modified flame retardant filler.

[0017] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the inorganic flame-retardant filler includes at least one of magnesium oxide, silicon dioxide, titanium dioxide, montmorillonite, hydrotalcite, and magnesium hydroxide.

[0018] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the LCST-type temperature-responsive polymer includes at least one of poly(N-alkyl acrylamide), polyvinyl ether, and polyether.

[0019] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the LCST-type temperature-responsive polymer includes at least one of poly(N-isopropylacrylamide), poly(N-vinylcaprolactam), poly(N,N-diethylacrylamide), poly(N-vinylformamide), polyvinyl methyl ether, polyethylene oxide, polyethylene glycol, poly(2-oxazoline), and a polyethylene oxide-polypropylene oxide block copolymer. Preferably, the LCST-type temperature-responsive polymer is at least one of poly(N-isopropylacrylamide), poly(N-vinylcaprolactam), poly(N,N-diethylacrylamide), and poly(N-vinylformamide). In this case, the LCST-type temperature-responsive polymer can decompose at high temperatures to produce nitrogen-containing gas (e.g., NH3), which can interact with inorganic flame retardant fillers and flame retardant synergists to enhance the flame retardant effect.

[0020] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the matrix resin includes at least one of ethylene-vinyl acetate copolymer (EVA), polyethylene (PE), polyolefin elastomer (POE), ethylene-butyl acrylate copolymer (EBA), maleic anhydride grafted polyolefin elastomer (POE-g-MAH), maleic anhydride grafted polyethylene (PE-g-MAH), maleic anhydride grafted ethylene-vinyl acetate copolymer (EVA-g-MAH), ethylene propylene diene monomer rubber (EPDM), and ethylene propylene rubber (EPR).

[0021] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the flame retardant synergist includes at least one of ammonium polyphosphate (APP), aluminum diethylphosphinate (ADP), melamine cyanurate (MCA), melamine polyphosphate (MPP), pentaerythritol, piperazine pyrophosphate, red phosphorus, and zinc borate.

[0022] As a preferred embodiment of the temperature-responsive flame-retardant composite material of the present invention, the temperature-responsive flame-retardant composite material further includes an additive, comprising 1 to 10 parts by weight of a color-changing additive and 0.5 to 2 parts by weight of an antioxidant. The color-changing additive comprises at least one of vanadium oxide, tungsten oxide, and a rare earth complex (e.g., a complex of rare earth ions such as europium and terbium with an organic ligand). When the temperature-responsive flame-retardant composite material includes the color-changing additive, it changes color when the temperature exceeds a threshold, thereby providing a visual fire warning.

[0023] In a second aspect, the present invention provides a method for preparing the above-mentioned temperature-responsive flame-retardant composite material, comprising the following steps: uniformly mixing the components and then melt-extruding to obtain the temperature-responsive flame-retardant composite material.

[0024] Preferably, the matrix resin and the modified flame retardant filler are first mixed and melt-extruded to obtain a masterbatch, and then the masterbatch is uniformly mixed with other components and melt-extruded to obtain a temperature-responsive flame retardant composite material.

[0025] In the above preparation method, a twin-screw extruder can be used for melt extrusion, the melt extrusion temperature is 145-195° C., and the screw speed is 250-350 rpm.

[0026] In a third aspect, the present invention provides a use of the above-mentioned temperature-responsive flame-retardant composite material in the preparation of cable sheaths.

[0027] In a fourth aspect, the present invention provides a cable sheath, which is made of the above-mentioned temperature-responsive flame-retardant composite material.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention utilizes a coating layer comprising an LCST-type temperature-responsive polymer to surface-modify an inorganic flame-retardant filler. This not only adjusts the surface polarity of the inorganic flame-retardant filler but also effectively prevents agglomeration of the inorganic flame-retardant filler, thereby improving the uniformity of its dispersion within the matrix resin. Furthermore, the coating layer comprising the LCST-type temperature-responsive polymer forms a flexible interface layer between the inorganic filler and the matrix resin to evenly distribute stress. Furthermore, the coating layer is capable of interpenetrating or entangled with the molecular chains of the matrix resin during melt blending, thereby effectively improving the mechanical properties of the flame-retardant composite material. Furthermore, the high temperature generated during combustion of the flame-retardant composite material causes the LCST-type temperature-responsive polymer in the coating layer to shrink, exposing the inorganic flame-retardant filler. This provides more flame-retardant active sites, which, in conjunction with the flame-retardant synergist, promote the formation of a dense carbon layer, achieving a triple synergistic flame retardancy of "physical barrier, chemical smoke suppression, and free radical quenching," thereby significantly improving the flame-retardant properties of the temperature-responsive flame-retardant composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the infrared spectrum of the modified flame retardant filler in Example 1;

[0031] Figure 2 2 are thermogravimetric analysis curves of the temperature-responsive flame-retardant composite materials in Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0032] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0033] Unless otherwise specified, other materials and reagents used in the examples can be obtained from commercial sources.

[0034] 1. Raw materials and reagents

[0035] 1) Matrix resin

[0036] Matrix resin 1 consists of PE, EBA, EVA, POE, and POE-g-MAH in a mass ratio of 2:2:2:4:1;

[0037] Matrix resin 2 consists of PE, EBA, EVA, POE, and POE-g-MAH in a mass ratio of 1:1:2:1:1;

[0038] Matrix resin 3 is EVA;

[0039] The matrix resin 4 is POE;

[0040] The brand of the above-mentioned PE is 749, and the manufacturer is Hanwha; the brand of EBA is 4210, and the manufacturer is Arkema; ​​the brand of EVA is 1833, and the manufacturer is Hanwha; the brand of POE is DF710, and the manufacturer is Mitsui Chemicals, Inc.; the brand of POE-g-MAH is MH5040, and the manufacturer is Mitsui Chemicals, Inc.

[0041] 2) Modified flame retardant filler

[0042] The modified flame retardant filler 1, the preparation method thereof comprises the following steps:

[0043] First, 50 g of flame retardant filler (composed of nano-silica, nano-magnesium oxide and magnesium hydroxide in a mass ratio of 1:1:2), 0.05 g of surfactant (sodium lauryl sulfate) and 500 mL of deionized water were mixed evenly, and then 2 g of temperature-responsive monomer (N-isopropylacrylamide) and 0.5 g of cross-linking agent (bis[2-(methacryloyloxy)ethyl]phosphate) were added thereto and continued to mix evenly; then, 0.005 g of initiator (azobisisobutyronitrile) was added, and the mixture was reacted at 70°C in a nitrogen atmosphere for 2 h, centrifuged and dried to obtain modified flame retardant filler 1.

[0044] The preparation method of modified flame retardant filler 2 is different from that of modified flame retardant filler 1 only in that the added amount of temperature responsive monomer is 3 g.

[0045] The preparation method of modified flame retardant filler 3 is different from that of modified flame retardant filler 1 only in that the added amount of temperature responsive monomer is 4 g.

[0046] The preparation method of modified flame retardant filler 4 is different from that of modified flame retardant filler 1 only in that the temperature-responsive monomer is N-vinyl caprolactam.

[0047] The preparation method of modified flame-retardant filler 5 is different from that of modified flame-retardant filler 1 only in that the temperature-responsive monomer is N,N-diethylacrylamide.

[0048] The preparation method of the modified flame retardant filler 6 is different from that of the modified flame retardant filler 1 only in that the flame retardant filler is montmorillonite.

[0049] The preparation method of the modified flame retardant filler 7 is different from that of the modified flame retardant filler 1 only in that the flame retardant filler is hydrotalcite.

[0050] The modified flame retardant filler 8, the preparation method thereof comprises the following steps:

[0051] 50 g of flame-retardant filler (composed of nano-silica, nano-magnesium oxide and magnesium hydroxide in a mass ratio of 1:1:2), 2 g of temperature-responsive monomer (N-isopropylacrylamide) and 0.5 g of cross-linking agent (bis[2-(methacryloyloxy)ethyl]phosphate) were mixed uniformly at room temperature to obtain modified flame-retardant filler 8.

[0052] The particle size D of the nano-silicon dioxide 50 The particle size of nano-magnesium oxide is 20nm. 50 The particle size of magnesium hydroxide is 600nm. 50 The particle size of montmorillonite is 3 μm. 50 The particle size D of hydrotalcite is 1.6 μm. 50 5μm.

[0053] 3) Flame retardant synergist

[0054] Flame retardant synergist 1 is composed of ADP, MPP, piperazine pyrophosphate and zinc borate in a mass ratio of 2:1:1:0.5;

[0055] Flame retardant synergist 2 is composed of ADP, MPP, piperazine pyrophosphate and zinc borate in a mass ratio of 3:1:1:1.5;

[0056] Flame retardant synergist 3 is ADP;

[0057] Flame retardant synergist 4 is MPP;

[0058] The brand of the above-mentioned ADP is HR915, and the manufacturer is Weihai Hairun; the manufacturer of MPP is Jinan Yunuo Chemical Co., Ltd.; the manufacturer of piperazine pyrophosphate is Guangzhou Yinyuan New Materials Co., Ltd.; and the manufacturer of zinc borate is American Borax Group.

[0059] 4) Additives

[0060] Color-changing agent 1 is vanadium dioxide, which is commercially available;

[0061] Color-changing agent 2 is tungsten oxide, which is commercially available;

[0062] The antioxidant is 1010, brand name is IRGANOX 1010, and the manufacturer is BASF.

[0063] 2. Various Examples and Comparative Examples

[0064] Table 1 Weight percentage of each component of the temperature-responsive flame-retardant composite material in Examples 1 to 14

[0065] Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Base resin 1 40 / / / 40 40 40 40 40 40 40 40 40 40 Base resin 2 / 40 / / / / / / / / / / / / Base resin 3 / / 40 / / / / / / / / / / / Base resin 4 / / / 40 / / / / / / / / / / Modified flame retardant filler 1 50 50 50 50 / / / / / / 50 50 50 50 Modified flame retardant filler 2 / / / / 50 / / / / / / / / / Modified flame retardant filler 3 / / / / / 50 / / / / / / / / Modified flame retardant filler 4 / / / / / / 50 / / / / / / / Modified flame retardant filler 5 / / / / / / / 50 / / / / / / Modified flame retardant filler 6 / / / / / / / / 50 / / / / / Modified flame retardant filler 7 / / / / / / / / / 50 / / / / Flame retardant synergist 1 10 10 10 10 10 10 10 10 10 10 / / / 10 Flame retardant synergist 2 / / / / / / / / / / 10 / / / Flame retardant synergist 3 / / / / / / / / / / / 10 / / Flame retardant synergist 4 / / / / / / / / / / / / 10 / Color-changing agent 1 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 / Color-changing agent 2 / / / / / / / / / / / / / 2.5 antioxidants 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

[0066] Table 2 Weight percentage of each component of the temperature-responsive flame-retardant composite material in Examples 15 and 16

[0067] Example 1 15 16 Base resin 1 40 40 80 Modified flame retardant filler 1 50 75 15 Flame retardant synergist 1 10 15 3 Color-changing agent 1 2.5 1 10 antioxidants 1.5 0.5 2

[0068] The preparation method of the temperature-responsive flame-retardant composite material in each embodiment includes the following steps:

[0069] According to the formula, the base resin and the modified flame-retardant filler are first mixed and then added to a twin-screw extruder for melt extrusion to obtain a masterbatch; the masterbatch, flame retardant synergist, color-changing agent and antioxidant are then added to an internal mixer for mixing. After mixing, the materials are added to a twin-screw extruder for melt extrusion to obtain a temperature-responsive flame-retardant composite material; wherein, the temperatures of each zone of the twin-screw extruder are: 145°C for zone 1, 165°C for zone 2, 185°C for zone 3, 195°C for zone 4, 195°C for zone 5, 185°C for zone 6, 175°C for zone 7 and 165°C for zone 8; the aspect ratio of the screw is 42:1, and the screw speed is 280 rpm.

[0070] Comparative Example 1

[0071] A temperature-responsive flame-retardant composite material comprises the following components in parts by weight: 40 parts of a base resin 1, 50 parts of a flame-retardant filler (composed of nano-silicon dioxide, nano-magnesium oxide, and magnesium hydroxide in a mass ratio of 1:1:2), 10 parts of a flame-retardant synergist 1, 2.5 parts of a color-changing agent 1, and 1.5 parts of an antioxidant.

[0072] The preparation method of the temperature-responsive flame-retardant composite material is the same as that in Example 1.

[0073] Comparative Example 2

[0074] A temperature-responsive flame-retardant composite material comprises the following components in parts by weight: 40 parts of a base resin 1, 50 parts of a modified flame-retardant filler 8, 10 parts of a flame-retardant synergist 1, 2.5 parts of a color-changing auxiliary agent 1, and 1.5 parts of an antioxidant.

[0075] The preparation method of the temperature-responsive flame-retardant composite material is the same as that in Example 1.

[0076] 3. Performance testing

[0077] 1) Tensile strength test: According to GB / T1040.3-2006, the specimen type is type 5 specimen, and the tensile rate is 500 mm / min;

[0078] 2) Elongation at break test: According to GB / T1040.3-2006, the specimen type is type 5 specimen, and the tensile rate is 500 mm / min;

[0079] 3) Smoke density test: According to GB / T8323.2-2008, the sample thickness is 1±0.1mm, 25kW / m 2 .

[0080] Table 3 Properties of temperature-responsive flame-retardant composite materials in various embodiments and comparative examples

[0081]

[0082] The data in Table 3 indicate that the temperature-responsive flame-retardant composite materials of Examples 1 to 16 all exhibited tensile strengths greater than or equal to 11 MPa and elongations at break exceeding 160%. Furthermore, their smoke densities under flame conditions were less than or equal to 81, and their smoke densities under flamelessness were less than or equal to 262, demonstrating that the temperature-responsive flame-retardant composite materials of the present invention exhibit both good flame retardancy and excellent mechanical properties. Furthermore, Example 1, Comparative Examples 1, and Comparative Examples 2 demonstrate that unmodified flame-retardant fillers or simply physically mixing inorganic flame-retardant fillers with temperature-responsive monomers and crosslinking agents are insufficient to effectively improve the flame retardancy and mechanical properties of the composite materials.

[0083] according to Figure 1 It can be seen that the modified sample has characteristic absorption peaks of the response monomer, such as 1548cm -1 The -NH bending vibration peak of the amide II band is at 1461 cm -1 The stretching vibration peak of -CN is at 2923cm, which is the characteristic absorption peak of amide. -1 At 2981cm -1The peaks at -CH2 and -CH3 of the isopropyl group in NIPAM are the stretching vibration peaks, indicating that the response monomer is successfully coated on the flame retardant filler, which means that the modified flame retardant filler is successfully prepared.

[0084] according to Figure 2 It can be found that when the temperature reaches 600° C., the mass residual rate of Comparative Example 1 is 38.8%, compared with the mass residual rate of Example 1 being 43.5%. It can be seen that the thermal stability of Example 1 is significantly improved.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A temperature-responsive flame-retardant composite material, characterized in that: The composition comprises the following components in parts by weight: 40-80 parts of base resin, 15-75 parts of modified flame retardant filler, 3-15 parts of flame retardant synergist; The modified flame retardant filler comprises an inorganic flame retardant filler and a coating layer provided on at least a portion of the surface of the inorganic flame retardant filler, wherein the coating layer comprises an LCST type temperature responsive high molecular polymer.

2. The temperature-responsive flame-retardant composite material according to claim 1, wherein: Based on the mass of the modified flame retardant filler, the mass percentage of the coating layer is 0.5% to 10%.

3. The temperature-responsive flame-retardant composite material according to claim 1, wherein: The particle size D of the inorganic flame retardant filler 50 It is 10nm~10μm.

4. The temperature-responsive flame-retardant composite material according to claim 1, wherein: The modified flame retardant filler is obtained by atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization of an inorganic flame retardant filler, a temperature responsive monomer and a crosslinking agent; The temperature-responsive monomer includes at least one of N-isopropylacrylamide, N-vinylcaprolactam, N,N-diethylacrylamide, N-vinylformamide, vinyl methyl ether, ethylene oxide, and ethylene glycol; and the cross-linking agent includes at least one of di[2-(methacryloyloxy)ethyl]phosphate and N,N'-methylenebisacrylamide.

5. The temperature-responsive flame-retardant composite material according to claim 1, wherein: The inorganic flame retardant filler includes at least one of magnesium oxide, silicon dioxide, titanium dioxide, montmorillonite, hydrotalcite, and magnesium hydroxide; And / or, the LCST-type temperature-responsive polymer includes at least one of poly(N-isopropylacrylamide), poly(N-vinylcaprolactam), poly(N,N-diethylacrylamide), poly(N-vinylformamide), polyvinyl methyl ether, polyethylene oxide, polyethylene glycol, poly(2-oxazoline), and polyethylene oxide-polypropylene oxide block copolymer.

6. The temperature-responsive flame-retardant composite material according to claim 1, wherein: The matrix resin includes at least one of ethylene-vinyl acetate copolymer, polyethylene, polyolefin elastomer, ethylene-butyl acrylate copolymer, maleic anhydride grafted polyolefin elastomer, maleic anhydride grafted polyethylene, maleic anhydride grafted ethylene-vinyl acetate copolymer, EPDM rubber, and EPDM rubber; And / or, the flame retardant synergist includes at least one of ammonium polyphosphate, aluminum diethylphosphinate, melamine cyanurate, melamine polyphosphate, pentaerythritol, piperazine pyrophosphate, red phosphorus, and zinc borate.

7. The temperature-responsive flame-retardant composite material according to claim 1, wherein: The temperature-responsive flame-retardant composite material further includes an auxiliary agent, which includes 1 to 10 parts by weight of a color-changing auxiliary agent and 0.5 to 2 parts by weight of an antioxidant; the color-changing auxiliary agent includes at least one of vanadium oxide, tungsten oxide, and a rare earth complex.

8. The method for preparing the temperature-responsive flame-retardant composite material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: uniformly mixing the components and then melting and extruding the components to obtain a temperature-responsive flame-retardant composite material.

9. Use of the temperature-responsive flame-retardant composite material according to any one of claims 1 to 7 in the preparation of cable sheaths.

10. A cable sheath, characterized in that: The cable sheath is made of the temperature-responsive flame-retardant composite material according to any one of claims 1 to 7.

Images