Hard carbon deposition graphene, preparation method thereof, high-wear-resistance flame-retardant modified HDPE (high-density polyethylene) pipe and preparation method thereof

Abstract

The invention relates to the field of graphene materials, and particularly discloses hard carbon deposition graphene and a preparation method thereof and a high-wear-resistance flame-retardant modified HDPE pipe and a preparation method thereof.The preparation method of the hard carbon deposition graphene comprises the following steps that graphene is put into a rotary tube furnace, nitrogen is introduced, heating is conducted, then acetylene is introduced, a constant-temperature reaction is conducted, and the graphene is obtained; and then gradually cooling to room temperature to obtain the hard carbon deposition graphene. The prepared hard carbon deposition graphene can be uniformly dispersed and stably exist in a high polymer material, the excellent performance of the graphene is fully played, and the wear resistance and flame retardance of the high polymer material, especially the high-wear-resistance flame-retardant modified HDPE pipe, can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of graphene materials, and more specifically, to a hard carbon-deposited graphene and a preparation method thereof, a highly wear-resistant and flame-retardant modified HDPE pipe and a preparation method thereof. Background Art

[0002] Graphene is a two-dimensional carbon nanomaterial composed of carbon atoms arranged in a hexagonal honeycomb lattice with sp² hybrid orbitals. It exhibits excellent electrical conductivity, wear resistance, flame retardancy, and static dissipation. Its unique honeycomb network structure effectively isolates oxygen and suppresses the release of heat, smoke, and degradation products. It has significant application potential and broad prospects in the wear-resistant and flame-retardant fields. Graphene is often blended with other substances to create functional composite materials, but its surface inertness makes it prone to aggregation and poorly compatible with polymer matrices. Existing techniques typically involve oxidizing graphene and then covalently modifying it. However, this preparation method is complex, and the modified product is not uniform and stable, failing to bond tightly with the polymer to achieve the desired oxygen-isolating and flame-retardant properties.

[0003] Polyethylene, a common polymer material, is the most produced and imported synthetic resin in my country. Due to its excellent water resistance, corrosion resistance, and impact resistance, it is often used as a pipe material. However, in some specialized applications, such as underground in coal, metal, and non-metallic mines, and in chemical and pharmaceutical plants exposed to high temperatures, flammable, and explosive media, slurry collides with the pipe, causing wear and shortening its service life. Furthermore, airborne dust rubs against the pipe, causing positive and negative charges to accumulate on the pipe and dust, respectively. When static charge accumulates to a certain level, it sparks. Polyethylene, when exposed to open flames, burns rapidly, releasing large amounts of harmful gases and causing production accidents. Currently, the common method for improving the flame retardancy and wear resistance of polyethylene pipes is to add flame retardants and wear-resistant fillers. However, this method has limited effectiveness, and the flame retardants are prone to precipitation and the wear-resistant fillers are not compatible, making it unsuitable for meeting the demand for higher-performance materials.

[0004] Therefore, how to provide a graphene material and its preparation method that can be closely combined with polymer materials, especially polyethylene, to give full play to the excellent properties of graphene is the key to realizing the application potential of graphene. Summary of the Invention

[0005] In order to improve the dispersibility and compatibility of graphene in polymer materials, the present application provides a hard carbon deposited graphene and a preparation method thereof, a highly wear-resistant and flame-retardant modified HDPE pipe and a preparation method thereof.

[0006] In a first aspect, the present application provides a method for preparing hard carbon deposited graphene, which adopts the following technical solution: A method for preparing hard carbon deposited graphene comprises the following steps: placing graphene in a rotary tube furnace, introducing nitrogen, heating, then introducing acetylene, reacting at a constant temperature, and then gradually cooling to room temperature to obtain hard carbon deposited graphene.

[0007] By adopting the above technical solution, the preparation method is simple, and after deposition, the graphene surface has a dense and uniform carbon coating layer, which improves the dispersibility of graphene. Graphene is not easy to agglomerate in polymer materials, which is conducive to the excellent performance of graphene and can increase the amount of graphene added. At the same time, there are uniform and abundant pores on the carbon coating layer obtained. After the hard carbon-deposited graphene is added to the organic polymer material, the organic material can penetrate the pores and form a certain mechanical lock with the graphene. When subjected to external force, the graphene is not easy to escape. Compared with the method of covalently modifying graphene to improve compatibility, it is simpler, more uniform and stable, and can be prepared on a large scale. At the same time, the carbon layer may form an effect similar to that of an intumescent flame retardant, isolating oxygen and heat, and the flame retardant and heat insulating effect of the hard carbon-deposited graphene obtained is better.

[0008] In a specific embodiment, the heating temperature is 700-750°C.

[0009] By adopting the above technical solution, the heating temperature is appropriate, the by-products are few, and the carbon layer on the surface of the hard carbon deposited graphene obtained is denser and more uniform, and the pores are more uniform and abundant.

[0010] In a specific embodiment, the heating process is a gradual temperature increase with a heating rate of 5-6°C / min.

[0011] By adopting the above technical solution, acetylene can be better adsorbed and diffused on the graphene surface, and the carbon layer on the surface of the hard carbon deposited graphene obtained is denser and more uniform, and the pores are more uniform and abundant.

[0012] In a specific embodiment, the particle size of the graphene is 10-15 μm.

[0013] By adopting the above technical solution, the deposition effect, the thickness of the carbon layer formed after deposition, and the pore size are reasonable relative to the particle size of the graphene sheet, and will not destroy the honeycomb network structure of the graphene. At the same time, the graphene will not be too small to form complete and uniform pores, so that the mechanical locking force formed between the pores and the organic matter is limited, and it cannot effectively isolate the hot oxygen, nor will it significantly reduce the compatibility in the organic matter. The obtained graphene has good dispersibility and wear resistance, and can exist evenly and stably in organic matter, especially ethylene.

[0014] In a second aspect, the present application provides a hard carbon-deposited graphene, which is prepared by the above-mentioned preparation method of hard carbon-deposited graphene.

[0015] By adopting the above technical solution, the hard carbon deposited graphene is easy to prepare, the preparation effect is uniform and stable, the dispersion is good and it is not easy to agglomerate, and it can exist uniformly and stably in organic matter, thereby improving the application range of graphene.

[0016] In a third aspect, the present application provides a highly wear-resistant and flame-retardant modified HDPE pipe, which adopts the following technical solution: A highly wear-resistant and flame-retardant modified HDPE pipe comprises the following raw materials in parts by mass: 75-90 parts of HDPE resin, 20-35 parts of UHMWPE, 1-4 parts of graphene, 0.2-0.5 parts of antioxidant, 0.5-1 parts of antibacterial agent, 10-15 parts of flame retardant, 1-3 parts of dispersant, and 2-5 parts of compatibilizer, wherein the graphene comprises the above-mentioned hard carbon deposited graphene.

[0017] By adopting the above technical solution and limiting the quality of each component in the HDPE pipe, the wear resistance and flame retardancy of the pipe are relatively stable and excellent. At the same time, the pipe has suitable viscosity and fluidity after melting, and can better penetrate into the pores of the hard carbon deposited graphene prepared in this application. The secondary structure of the hard carbon deposited graphene monomer is evenly dispersed in the pipe, locked with the resin and stacked layer by layer to form a dense isolation layer. The obtained HDPE pipe has good wear resistance and flame retardancy.

[0018] In a specific embodiment, the graphene further comprises amino-terminated hyperbranched polyamide grafted graphene oxide, and the raw materials further comprise maleic anhydride.

[0019] Hyperbranched polyamide is a multifunctional polymer with a highly branched structure and rich amino functional groups. By adding a certain mass of amino-terminated hyperbranched polyamide grafted graphene oxide, its hyperbranched structure and rich reactive functional groups can improve the bonding strength between graphene and the internal components of the pipe, achieve better interpenetration and promote the cross-linking of the substrate. At the same time, the applicant found that the wear resistance and flame retardancy of the pipe prepared by jointly adding amino-terminated hyperbranched polyamide grafted graphene oxide and hard carbon deposited graphene are significantly improved. It may be that at this time, the side chains of the amino-terminated hyperbranched polyamide grafted graphene oxide and the pores on the surface of the hard carbon deposited graphene undergo a certain degree of interpenetration and locking, or it may be that the large number of amino groups on the amino-terminated hyperbranched polyamide grafted graphene oxide and the hydroxyl groups of the hard carbon deposited graphene undergo electrostatic assembly, which together form a better protective network for the pipe. At the same time, a certain amount of maleic anhydride is added to further form cross-links and generate hydrogen bonds with the large number of amino groups on the amino-terminated hyperbranched polyamide grafted graphene oxide. The internal structure of the pipe is more compact and dense, and the graphene can form a tight connection in the pipe. The lamellar structure and carbon layer form a uniform and tight protection for the pipe, fully blocking the exchange of oxygen and external gases and suppressing heat. The wear resistance and flame retardant performance of the pipe are greatly improved.

[0020] In a specific embodiment, the mass ratio of the amino-terminated hyperbranched polyamide grafted graphene oxide to the hard carbon deposited graphene is 2:1.

[0021] By adopting the above technical solution, the mass ratio of the amino-terminated hyperbranched polyamide grafted graphene oxide and the hard carbon deposited graphene is limited, the internal structure of the prepared pipe is more uniform and tight, and the graphene has a good protective effect on the pipe.

[0022] In a specific embodiment, the preparation steps of amino-terminated hyperbranched polyamide grafted graphene oxide include: adding graphene oxide to a solvent, ultrasonically dispersing, then adding polyvinyl pyrrolidone solution, stirring evenly, adding amino-terminated hyperbranched polyamide, adjusting the pH value, heating for reaction, filtering, washing, and drying to obtain amino-terminated hyperbranched polyamide grafted graphene oxide.

[0023] By adopting the above technical solution, the preparation method is simple, uniform hyperbranched branches are formed on the surface of graphene, the branches are tightly combined in the tube, the length of the branches is appropriate, and the locking and entanglement effect with the hard carbon deposited graphene is good.

[0024] In a fourth aspect, the present application provides a method for preparing a highly wear-resistant and flame-retardant modified HDPE pipe, which adopts the following technical solution: A method for preparing a highly wear-resistant and flame-retardant modified HDPE pipe comprises the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer to obtain a premix at a mixing temperature of 120°C-150°C; S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 180°C-230°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded to obtain a HDPE pipe.

[0025] By adopting the above technical solution, the raw materials are fully melted and evenly mixed without degradation, the graphene two-dimensional structure is evenly dispersed in the pipe, the structure is stable and not destroyed, and a dense isolation layer is formed by stacking layers inside the pipe. The wear resistance and flame retardant properties of the produced pipe are good.

[0026] In summary, this application has the following beneficial effects: 1. This application improves the dispersibility and flame retardancy of graphene by uniformly depositing a layer of hard carbon material on the surface of graphene, and forms uniform and rich pores so that it can exist stably in high molecular organic matter, and further limits the process parameters of the deposition process and the particle size of graphene, so that the thickness of the carbon layer and the pore size of the obtained graphene surface are more suitable.

[0027] 2. By limiting the composition and quality of the HDPE pipe raw materials, this application produces HDPE pipes with optimal viscosity and fluidity, ensuring pipe strength while effectively penetrating the pores of the hard carbon-deposited graphene surface to form mechanical bonds. This results in a uniform and stable graphene sheet structure within the resulting HDPE pipe, providing excellent protection and making the pipe more wear-resistant and flame-retardant.

[0028] 3. This application adds a certain mass of amino-terminated hyperbranched polyamide grafted graphene oxide and hard carbon deposited graphene into the HDPE pipe at the same time and limits the mass ratio of the two, and further adds maleic anhydride to form a certain amount of interpenetration and cross-linking in the pipe to form a dense graphene protection network. The resulting HDPE pipe has good wear resistance and flame retardancy. DETAILED DESCRIPTION

[0029] The following is a more specific description of the technical solution of the present invention in combination with several specific implementation examples. The embodiments are only part of the embodiments of the present invention, not all of them. The following specific embodiments can be combined with each other, and the same or similar concepts or processes therein may not be repeated in some embodiments.

[0030] Unless otherwise specified, the experimental reagents in the preparation examples, embodiments, and comparative examples are conventional commercial brands or obtained through conventional preparation processes.

[0031] In the preparation examples, working examples, and comparative examples, graphene with an average particle size of 10 μm was purchased from Ruixi Biotechnology's R-DKD-006; graphene with an average particle size of 5 μm was purchased from ACS Material's NF022; and graphene oxide with an average particle size of 10 μm was purchased from Jicang Nano. HDPE was purchased from Shanghai Petrochemical's YGH041T, UHMWPE was purchased from Mitsui Chemicals' 240M, antioxidant was purchased from Borealis' FB1520, antibacterial agent was purchased from Microarmor's Micro-KF108, flame retardant was purchased from Shijiazhuang Qibo Chemical Co., Ltd.'s E01, dispersant was purchased from SCG Chemicals' LP0100F, compatibilizer was purchased from Dongguan Yunfeiyang Plastic Technology Co., Ltd.'s PE-1101, item number 11010, amino-terminated hyperbranched polyamide was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., aminosilane coupling agent was purchased from Chunqi Chemical's KH580, and 1250-mesh flake mica powder was purchased from Shifeng SF-YM.

[0032] Preparation Example Preparation Example 1: Graphene oxide grafted with amino-terminated hyperbranched polyamide: 10 g of graphene oxide with an average particle size of 10 μm was added to 400 g of n-butanol, and ultrasonic dispersion was performed at 300 W for 30 minutes. Then, 600 g of 10 wt% polyvinyl pyrrolidone solution was added and stirred evenly. 200 g of amino-terminated hyperbranched polyamide was added, the pH value was adjusted to 9, and the reaction was heated at 50°C. After 12 hours, the mixture was filtered, washed with deionized water, and dried to obtain amino-terminated hyperbranched polyamide grafted graphene oxide.

[0033] Preparation Example 2: Aminosilane coupling agent modified graphene oxide: 15 g of graphene oxide with an average particle size of 10 μm and 20 g of aminosilane coupling agent were added to 200 ml of 25% wt ethanol aqueous solution, stirred evenly, heated to 85° C., stirred for 2 hours, filtered, washed with deionized water three times, and dried to obtain aminosilane coupling agent-modified graphene oxide.

[0034] Preparation Example 3: Amino-terminated hyperbranched polyamide grafted flaky mica powder: 10 g of 1250 mesh flaky mica powder was added to 400 g of n-butanol, and ultrasonic dispersion was performed at 300 W for 30 minutes. Then, 600 g of 10 wt% polyvinyl pyrrolidone solution was added and stirred evenly. 200 g of amino-terminated hyperbranched polyamide was added, and the pH value was adjusted to 9. The mixture was heated at 50° C. for reaction. After 12 hours, the mixture was filtered, washed with deionized water, and dried to obtain amino-terminated hyperbranched polyamide grafted flaky mica powder.

[0035] Example Example 1: Preparation of hard carbon deposited graphene: Graphene with an average particle size of 10 μm was placed in a rotary tube furnace, nitrogen was introduced at a nitrogen flow rate of 50 mL / min, and the temperature was increased to 750°C at a heating rate of 5°C / min. Then acetylene was introduced at an acetylene flow rate of 22 mL / min, and the reaction was carried out at a constant temperature for 70 minutes. The temperature was then gradually lowered to room temperature to obtain hard carbon deposited graphene.

[0036] Example 2: Preparation of hard carbon deposited graphene: Graphene with an average particle size of 5 μm was placed in a rotary tube furnace, nitrogen was introduced at a nitrogen flow rate of 50 mL / min, and the temperature was increased to 750°C at a heating rate of 5°C / min. Then acetylene was introduced at an acetylene flow rate of 22 mL / min, and the reaction was carried out at a constant temperature for 70 minutes. The temperature was then gradually lowered to room temperature to obtain hard carbon deposited graphene.

[0037] Example 3: Preparation of hard carbon deposited graphene: Graphene with an average particle size of 10 μm was placed in a rotary tube furnace, nitrogen was introduced at a nitrogen flow rate of 50 mL / min, and the temperature was increased to 750°C at a heating rate of 10°C / min. Then acetylene was introduced at an acetylene flow rate of 22 mL / min, and the reaction was carried out at a constant temperature for 70 minutes. The temperature was then gradually lowered to room temperature to obtain hard carbon deposited graphene.

[0038] Example 4: Preparation of hard carbon deposited graphene: Graphene with an average particle size of 10 μm was placed in a rotary tube furnace, nitrogen was introduced at a nitrogen flow rate of 50 mL / min, and the temperature was increased to 800°C at a heating rate of 5°C / min. Then acetylene was introduced at an acetylene flow rate of 22 mL / min, and the reaction was carried out at a constant temperature for 70 minutes. The temperature was then gradually lowered to room temperature to obtain hard carbon deposited graphene.

[0039] Example 5: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This embodiment includes the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 30 g of hard carbon-deposited graphene prepared in Example 1, 3 g of antioxidant, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0040] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, hard carbon deposited graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0041] Example 6: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This embodiment includes the following raw materials: 750 g of HDPE resin, 350 g of UHMWPE, 30 g of hard carbon-deposited graphene prepared in Example 1, 2 g of antioxidant, 5 g of antibacterial agent, 100 g of flame retardant, 30 g of dispersant, and 50 g of compatibilizer.

[0042] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, hard carbon deposited graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0043] Example 7: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This embodiment includes the following raw materials: 900 g of HDPE resin, 200 g of UHMWPE, 30 g of hard carbon-deposited graphene prepared in Example 1, 5 g of antioxidant, 10 g of antibacterial agent, 100 g of flame retardant, 30 g of dispersant, and 20 g of compatibilizer.

[0044] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, hard carbon deposited graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0045] Example 8: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This embodiment includes the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 30 g of hard carbon-deposited graphene prepared in Example 2, 3 g of antioxidant, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0046] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, hard carbon deposited graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0047] Example 9: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This embodiment includes the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 30 g of hard carbon-deposited graphene prepared in Example 3, 3 g of antioxidant, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0048] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, hard carbon deposited graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0049] Example 10: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This embodiment includes the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 30 g of hard carbon-deposited graphene prepared in Example 4, 3 g of antioxidant, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0050] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, hard carbon deposited graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0051] Example 11: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This example contains the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 20 g of hard carbon-deposited graphene prepared in Example 1, 10 g of amino-terminated hyperbranched polyamide-grafted graphene oxide prepared in Preparation Example 1, 10 g of maleic anhydride, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0052] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin prepared in S1, UHMWPE, hard carbon-deposited graphene, amino-terminated hyperbranched polyamide grafted graphene oxide, dispersant, and compatibilizer were mixed in a high-speed mixer to obtain a premix at a mixing temperature of 120°C. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0053] Example 12: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This example contains the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 20 g of hard carbon-deposited graphene prepared in Example 1, 10 g of aminosilane coupling agent-modified graphene oxide prepared in Preparation Example 2, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0054] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin prepared in S1, UHMWPE, hard carbon-deposited graphene, aminosilane coupling agent-modified graphene oxide, dispersant, and compatibilizer are mixed in a high-speed mixer to obtain a premix at a mixing temperature of 120°C. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0055] Example 13: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This embodiment contains the following raw materials: 850g of HDPE resin, 325g of UHMWPE, 20g of hard carbon-deposited graphene prepared in Example 1, 10g of amino-terminated hyperbranched polyamide grafted flaky mica powder prepared in Preparation Example 3, 3g of antibacterial agent, 120g of flame retardant, 20g of dispersant, and 30g of compatibilizer.

[0056] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin prepared in S1, UHMWPE, hard carbon-deposited graphene, amino-terminated hyperbranched polyamide grafted flaky mica powder, dispersant, and compatibilizer are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0057] Example 14: Preparation of highly wear-resistant and flame-retardant modified HDPE pipe: This example contains the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 15 g of hard carbon-deposited graphene prepared in Example 1, 15 g of amino-terminated hyperbranched polyamide-grafted graphene oxide prepared in Preparation Example 1, 10 g of maleic anhydride, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0058] This example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin prepared in S1, UHMWPE, hard carbon-deposited graphene, amino-terminated hyperbranched polyamide grafted graphene oxide, dispersant, and compatibilizer were mixed in a high-speed mixer to obtain a premix at a mixing temperature of 120°C. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0059] Comparative Example Comparative Example 1: Preparation of modified HDPE pipe: This comparative example contains the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 30 g of graphene, 3 g of antibacterial agent, 120 g of flame retardant, 20 g of dispersant, and 30 g of compatibilizer.

[0060] This comparative example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer at a mixing temperature of 120°C to obtain a premix. S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0061] Comparative Example 2: Preparation of modified HDPE pipe: This comparative example contains the following raw materials: 850 g of HDPE resin, 325 g of UHMWPE, 30 g of graphene oxide modified with an aminosilane coupling agent obtained in Preparation Example 2, 3 g of an antibacterial agent, 120 g of a flame retardant, 20 g of a dispersant, and 30 g of a compatibilizer.

[0062] This comparative example was prepared according to the following steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin prepared in S1, UHMWPE, aminosilane coupling agent-modified graphene oxide, dispersant, and compatibilizer are mixed in a high-speed mixer to obtain a premix at a mixing temperature of 120°C. S3: melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 200°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded at 180° C. to obtain a HDPE pipe.

[0063] Performance testing methods 1. Wear resistance: The wear resistance of the samples of each embodiment and comparative example was tested in accordance with the EN660-2 wear resistance test standard. The order of wear resistance grades was T grade > P grade > M grade > F grade. The test results are shown in Table 1.

[0064] 2. Flame retardant properties The flame retardancy of the sample slices of each embodiment and comparative example was tested with reference to UL94. The order of flame retardancy levels was 5-V>V-0>V-1>V-2. The test results are shown in Table 1.

[0065] Table 1 Performance Group Wear resistance grade Flame retardant grade Example 5 P V0 Example 6 P V0 Example 7 P V0 Example 8 M V1 Example 9 M V0 Example 10 M V0 Example 11 T 5-V Example 12 M 5-V Example 13 M V-1 Example 14 P 5-V Comparative Example 1 F V-2 Comparative Example 2 F V-2 In combination with Examples 1-4, Example 5, Examples 8-10, Comparative Examples 1-2 and Table 1, the carbon layer on the surface of the hard carbon deposited graphene prepared in the present application is dense and uniform, and has rich pores, which greatly improves its dispersibility and stability in organic polymer materials. The interior of the prepared pipe has a uniform graphene protective insulation layer, which fully exerts the wear resistance and flame retardant properties of graphene, and the prepared pipe has good performance.

[0066] In combination with Examples 5-7, Examples 11-14 and Table 1, the present application limits the component mass of the HDPE pipe, uses hard carbon deposited graphene as a wear-resistant and flame-retardant filler, adds hyperbranched polyamide grafted graphene oxide and maleic anhydride, and further limits the hyperbranched polyamide grafted graphene oxide and hard carbon deposited graphene. The internal structure of the obtained pipe is uniform and dense, and the different components are cross-linked, interlaced, and entangled, and the wear resistance and flame retardant properties are good.

[0067] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing hard carbon deposited graphene, characterized in that: The method comprises the following steps: placing graphene into a rotary tube furnace, introducing nitrogen, heating, then introducing acetylene, reacting at a constant temperature, and then gradually cooling to room temperature to obtain hard carbon deposited graphene, wherein the graphene has a particle size of 10-15 μm, and the heating process is a gradual heating process with a heating rate of 5-6°C / min.

2. The method for preparing hard carbon deposited graphene according to claim 1, wherein: The heating temperature is 700-750°C.

3. A hard carbon deposited graphene, characterized in that It is prepared by the preparation method according to any one of claims 1 to 2.

4. A highly wear-resistant and flame-retardant modified HDPE pipe, characterized in that: The method comprises the following raw materials in parts by mass: 75-90 parts of HDPE resin, 20-35 parts of UHMWPE, 1-4 parts of graphene, 0.2-0.5 parts of antioxidant, 0.5-1 parts of antibacterial agent, 10-15 parts of flame retardant, 1-3 parts of dispersant, and 2-5 parts of compatibilizer, wherein the graphene comprises the hard carbon deposited graphene according to claim 3.

5. The highly wear-resistant and flame-retardant modified HDPE pipe according to claim 4, characterized in that: The graphene further comprises amino-terminated hyperbranched polyamide grafted graphene oxide, and the raw materials further comprise maleic anhydride.

6. The highly wear-resistant and flame-retardant modified HDPE pipe according to claim 5, characterized in that: The mass ratio of the amino-terminated hyperbranched polyamide grafted graphene oxide and the hard carbon deposited graphene is 2:

1.

7. The highly wear-resistant and flame-retardant modified HDPE pipe according to claim 5, characterized in that: The preparation steps of the amino-terminated hyperbranched polyamide grafted graphene oxide include: adding graphene oxide to a solvent, ultrasonically dispersing it, then adding a polyvinyl pyrrolidone solution, stirring evenly, adding the amino-terminated hyperbranched polyamide, adjusting the pH value, heating for reaction, filtering, washing, and drying to obtain the amino-terminated hyperbranched polyamide grafted graphene oxide.

8. A method for preparing a highly wear-resistant and flame-retardant modified HDPE pipe according to any one of claims 4 to 7, characterized in that: The method comprises the following preparation steps: S1: Raw material pretreatment: weigh each component by mass and dry to obtain pretreated raw materials; S2: Premixing: The HDPE resin, UHMWPE, graphene, dispersant, and compatibilizer prepared in S1 are mixed in a high-speed mixer to obtain a premix at a mixing temperature of 120°C-150°C; S3: Melt blending: melt blending the premix prepared in S2 and adding the remaining components to obtain a melt blend with a melting temperature of 180°C-230°C; S4: Extrusion molding: The melt blend prepared in S3 is extruded to obtain a HDPE pipe.