A high temperature resistant PE power pipe and its preparation method

Abstract

The present invention discloses a high-temperature resistant PE power pipe and a preparation method thereof, belonging to the technical field of power pipe preparation. 100 parts of polyethylene, 15-25 parts of filler, 10-15 parts of flame retardant, 3-6 parts of plasticizer, 1-2 parts of lubricant, 0.5-2 parts of UV absorber, 0.5-2 parts of antioxidant, and 0.01-0.1 parts of initiator are weighed by weight, added to a high-speed mixer for mixing, then melt-blended in an internal mixer, and finally introduced into plastic pipe processing equipment for extrusion, cooling, molding, and cutting to obtain the PE power pipe. The flame retardant, filler, and polyethylene of the present invention form a cross-linked hybrid network structure, so that the flame retardant and filler are highly dispersed and stably present in the network structure, are not easily migrated or detached, and can maximize their own effects. As a result, the PE power pipe of the present invention has both excellent flame-promoting ability and can maintain good mechanical and physical properties in high-temperature environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power pipe preparation, and in particular, relates to a high-temperature resistant PE electric power pipe and a preparation method thereof. Background Art

[0002] Power pipes are used in power construction technology to protect and support cables. They are typically manufactured from materials such as PVC (polyvinyl chloride), PE (polyethylene), and PP (polypropylene). PE power pipes are widely used due to their excellent electrical insulation and ease of construction. However, with the continuous advancement of industry and urbanization, the continuous upgrading of power systems, and the expansion of power grids, the requirements for power transmission equipment are also increasing. In particular, PE power pipes have insufficient heat resistance in high-temperature environments, which limits their reliability and service life.

[0003] In addition, during the operation of the power system, if electrical equipment fails, local current overload can easily generate a large amount of heat in a short period of time, causing a fire. Therefore, the power pipe also needs to have the ability to prevent the spread of flames to ensure the safe operation of the power system, thereby reducing harm to the environment and personnel and reducing economic losses. Chinese patent CN104945712A discloses a method for preparing a flame-retardant polyethylene composite material. The method comprises preparing a powder of expandable graphite coated with nano-hydroxybismuth oxide, mixing it with polyethylene through a rheometer, pressing it into shape, and cooling it to room temperature. In this invention, the powder of expandable graphite coated with nano-hydroxybismuth oxide is an inorganic material, so the compatibility between the powder and polyethylene is poor. Therefore, the flame retardant effect of the prepared polyethylene composite material needs to be improved. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a high-temperature resistant PE power pipe and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A high-temperature resistant PE power pipe comprises the following raw materials in parts by weight: 100 parts of polyethylene, 15-25 parts of filler, 10-15 parts of flame retardant, 3-6 parts of plasticizer, 1-2 parts of lubricant, 0.5-2 parts of ultraviolet absorber, 0.5-2 parts of antioxidant, and 0.01-0.1 parts of initiator.

[0007] Furthermore, the filler is prepared by the following steps:

[0008] (1) Add hydroxymethyltriethoxysilane, maleic anhydride, DMAP (4-dimethylaminopyridine) and chloroform to a three-necked flask under nitrogen protection, stir and heat to 50°C, keep warm and react for 12 hours. After the reaction is completed, cool to room temperature, then distill under reduced pressure, purify by column chromatography (the eluent is a mixed solution of methanol, ethyl acetate and petroleum ether, and the volume ratio of methanol, ethyl acetate and petroleum ether is 1:1:5), and finally distill under reduced pressure to obtain a modified coupling agent; the dosage ratio of hydroxymethyltriethoxysilane, maleic anhydride, DMAP and chloroform is 19g:10.4g:0.6g:200mL;

[0009] Under the catalytic action of DMAP, the molar ratio of hydroxymethyltriethoxysilane to maleic anhydride is controlled to be 1:1.05-1.1, and then esterification reaction occurs between hydroxymethyltriethoxysilane and maleic anhydride. The reaction process is as follows:

[0010]

[0011] (2) Add titanium dioxide, heavy calcium carbonate, aluminum oxide and anhydrous ethanol into a three-necked flask, stir evenly, and then add acetic acid to adjust the pH to 4; disperse the modified coupling agent in deionized water under nitrogen protection, stir and dissolve, and then transfer it to the above three-necked flask. After the transfer is completed, stir and heat to 65°C, keep warm and react for 1 hour. After the reaction is completed, cool to room temperature, centrifuge, take the precipitate and ultrasonically disperse it in anhydrous ethanol, and finally dry it at 80°C for 12 hours to obtain the filler.

[0012] Furthermore, the mass ratio of the titanium dioxide, heavy calcium carbonate and aluminum oxide is 3:2:3.

[0013] Furthermore, the titanium dioxide is rutile titanium dioxide.

[0014] Furthermore, the mass ratio of the total mass of the titanium dioxide, heavy calcium carbonate, and aluminum oxide to the mass of the modified coupling agent is 16:1.

[0015] Rutile titanium dioxide has excellent high-temperature resistance, typically withstanding temperatures exceeding 800°C. Its structure is relatively stable in high-temperature environments and is not susceptible to discoloration or decomposition. Therefore, adding titanium dioxide to PE power pipes can improve their high-temperature resistance. Furthermore, rutile titanium dioxide can enhance the light and weather resistance of PE power pipes. Adding heavy calcium carbonate to PE power pipes can also improve their heat resistance. Alumina, with its high melting point and excellent high-temperature resistance, can improve its high-temperature resistance, allowing it to maintain good mechanical and physical properties even in high-temperature environments.

[0016] The titanium dioxide, heavy calcium carbonate, and aluminum oxide treated with a modified coupling agent improve their dispersion in the PE power pipe, enhancing compatibility between the filler and organic materials such as antioxidants and UV absorbers. Furthermore, the filler surface contains carboxyl groups, which chemically bond with the hydroxyl groups on the flame retardant surface. The filler surface also contains carbon-carbon double bonds, which, when activated by an initiator, chemically bond with unreacted carbon-carbon double bonds at the ends of the polyethylene and the flame retardant. This further disperses and stabilizes the filler within the PE power pipe, maximizing its effectiveness and ensuring that the PE power pipe maintains excellent mechanical and physical properties even in high-temperature environments.

[0017] Furthermore, the flame retardant is prepared by the following steps:

[0018] S1. Under nitrogen protection, tri(2-chloroethyl) phosphate, triethylamine, and toluene were added to a three-necked flask, stirred to dissolve, and then bis(trimethylsilylmethyl)amine was slowly added. After the addition was complete, the temperature was raised to 60°C and stirred for reaction for 4 hours. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure. Purification was performed by column chromatography (a mixed solvent of chloroform and diethyl ether was selected as the eluent, and the volume ratio of chloroform to diethyl ether was 8:2). Distillation under reduced pressure gave intermediate 1; the amount ratio of tri(2-chloroethyl) phosphate, bis(trimethylsilylmethyl)amine, triethylamine, and toluene was 31 mL:59 g:25 mL:240 mL;

[0019] Triethylamine is used as an acid-binding agent, and the molar ratio of tris(2-chloroethyl) phosphate and bis(trimethylsilylmethyl)amine is controlled to be 1:2.05-2.1. The -Cl of tris(2-chloroethyl) phosphate and the -NH- of bis(trimethylsilylmethyl)amine undergo a substitution reaction. The reaction process is as follows:

[0020]

[0021] S2. Under nitrogen protection, add intermediate 1, triethylamine and dimethyl sulfoxide into a three-necked flask, stir and dissolve, then slowly add 2-amino-4,6-dichloro-S-triazine, heat to 70°C and stir to react for 5 hours, cool to room temperature after the reaction, distill under reduced pressure, purify by column chromatography (a mixed solvent of benzene and methanol is selected as the eluent, and the volume ratio of benzene and methanol is 9:1), and finally distill under reduced pressure to obtain intermediate 2; the amount ratio of intermediate 1, 2-amino-4,6-dichloro-S-triazine, triethylamine and dimethyl sulfoxide is 59g:17g:16mL:250mL;

[0022] Triethylamine is used as an acid-binding agent to control the molar ratio of intermediate 1 and 2-amino-4,6-dichloro-S-triazine to be 1:1-1.05. The -Cl of intermediate 1 reacts with the -NH2 of 2-amino-4,6-dichloro-S-triazine to undergo a nucleophilic substitution reaction. The reaction process is as follows:

[0023]

[0024] S3. Under nitrogen protection, add intermediate 2, pyridine and dimethyl sulfoxide into a dry brown three-necked flask, stir thoroughly until completely dissolved, then slowly add 2-methylene-1,3-propanediol, stir and heat to 50°C, keep warm and react for 3 hours. After the reaction is completed, cool to room temperature, distill under reduced pressure, purify by column chromatography (a mixed solvent of chloroform and acetone is selected as the eluent, and the volume ratio of chloroform and acetone is 17:3), and distill under reduced pressure to obtain a flame retardant; the amount ratio of intermediate 2, 2-methylene-1,3-propanediol, pyridine and dimethyl sulfoxide is 28g:6.8mL:7mL:200mL.

[0025] Under heating conditions, the molar ratio of intermediate 2 and 2-methylene-1,3-propanediol is controlled to be 1:2.1-2.2, and then the -Cl of intermediate 2 and the -OH of 2-methylene-1,3-propanediol undergo a substitution reaction. The reaction process is as follows:

[0026]

[0027] The flame retardant contains abundant halogen-free flame-retardant elements, including nitrogen, phosphorus, and silicon. These elements work synergistically to prevent the escape of decomposition products generated by combustion, dilute combustible gases, and inhibit the thermal decomposition of the polymer material, achieving high flame retardancy, low smoke emission, and low toxicity. Therefore, the flame retardant of this invention can significantly enhance the flame retardancy and smoke suppression properties of PE power pipes. Furthermore, the flame retardant contains multiple methyl groups at the end. The three hydrogen atoms on the methyl groups resemble an open umbrella, making the flame retardant of this invention somewhat hydrophobic, thereby enhancing the anti-fouling and water-repellent properties of the PE power pipes of this invention.

[0028] Under the action of the initiator, the carbon-carbon double bonds in the flame retardant can chemically bond with the unreacted carbon-carbon double bonds at the end of the polyethylene and the surface of the filler. The flame retardant can then be grafted onto the polyethylene macromolecular chain and simultaneously connect to the filler, thereby forming a cross-linked hybrid network structure. The flame retardant is stably present in this network structure and is not easily affected by the external environment, migrating or escaping. It fully exerts its flame retardant and smoke suppression effects, giving the PE power pipe of the present invention an excellent ability to prevent the spread of flames, thereby ensuring the safe operation of the power system, thereby reducing harm to the environment and personnel, and reducing economic losses. At the same time, the flame retardant adds silicone segments and heterocyclic structures to the polymer material, thereby improving the high temperature resistance of the PE power pipe. The cross-linked hybrid network structure further improves the high temperature resistance of the PE power pipe.

[0029] Furthermore, the plasticizer is one or more of epoxy soybean oil, dibutyl phthalate, and diisononyl phthalate.

[0030] Furthermore, the lubricant is one or more of stearic acid, butyl stearate, and ethylene bisstearamide.

[0031] Furthermore, the ultraviolet absorber is one or more of ultraviolet absorber UV-326, ultraviolet absorber UV-3638, and ultraviolet absorber UV-531.

[0032] Furthermore, the antioxidant is one or more of antioxidant 1076, antioxidant 1035, and antioxidant 1010.

[0033] Furthermore, the initiator is one or more of di(2-ethylhexyl) peroxydicarbonate, dibenzoyl peroxide, and dicumyl peroxide.

[0034] A method for preparing a high-temperature resistant PE power pipe comprises the following steps:

[0035] Weigh each raw material by weight, add each raw material into a high-speed mixer and mix evenly, then put it into an internal mixer for melt blending, and finally introduce it into a plastic pipe processing equipment for extrusion, cooling, molding, and cutting to obtain a high-temperature resistant PE power pipe.

[0036] Beneficial effects of the present invention: The flame retardant, filler and polyethylene of the present invention form a cross-linked hybrid network structure, so the flame retardant and filler are highly dispersed and stably present in the network structure, and are not easily affected by the external environment, migrated or escaped, and can maximize their own effects. Therefore, the PE power pipe of the present invention has an excellent ability to prevent the spread of flames and can maintain good mechanical and physical properties in a high temperature environment. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] Example 1, preparing filler, the specific steps are as follows:

[0039] (1) Under nitrogen protection, 19 g of hydroxymethyltriethoxysilane, 10.4 g of maleic anhydride, 0.6 g of DMAP and 200 mL of chloroform were added to a 500 mL three-necked flask, and the temperature was raised to 50 ° C with stirring. The reaction was kept warm for 12 h. After the reaction was completed, it was first cooled to room temperature, then distilled under reduced pressure, and purified by column chromatography (the eluent was a mixed solution of methanol, ethyl acetate and petroleum ether, and the volume ratio of methanol, ethyl acetate and petroleum ether was 1:1:5). Finally, distilled under reduced pressure to obtain a modified coupling agent;

[0040] (2) Add 12g of rutile titanium dioxide, 8g of heavy calcium carbonate, 12g of aluminum oxide and 200mL of anhydrous ethanol into a 500mL three-necked flask, stir evenly and add acetic acid to adjust the pH to 4; disperse 2g of modified coupling agent in 20mL of deionized water under nitrogen protection, stir and dissolve, and transfer to the above three-necked flask. After the transfer is complete, stir and heat to 65℃, keep warm and react for 1h. After the reaction is completed, cool to room temperature, centrifuge, take the precipitate and ultrasonically disperse it in anhydrous ethanol, and finally dry it at 80℃ for 12h to obtain the filler.

[0041] Example 2, preparing a flame retardant, the specific steps are as follows:

[0042] S1. Under nitrogen protection, 31 mL of tris(2-chloroethyl) phosphate, 25 mL of triethylamine, and 240 mL of toluene were added to a 500 mL three-necked flask, stirred to dissolve, and then 59 g of bis(trimethylsilylmethyl)amine was slowly added. After the addition was complete, the temperature was raised to 60°C and stirred for 4 h. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure. Purification was performed by column chromatography (a mixed solvent of chloroform and diethyl ether was selected as the eluent, with a volume ratio of chloroform to diethyl ether of 8:2). Distillation under reduced pressure gave Intermediate 1.

[0043] S2. Under nitrogen protection, 59 g of intermediate 1, 16 mL of triethylamine, and 250 mL of dimethyl sulfoxide were added to a 500 mL three-necked flask, stirred to dissolve, and then 17 g of 2-amino-4,6-dichloro-S-triazine was slowly added. After the addition was complete, the temperature was raised to 70°C and stirred for reaction for 5 h. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure. Purification was performed by column chromatography (a mixed solvent of benzene and methanol was selected as the eluent, with a volume ratio of benzene and methanol of 9:1). Finally, distillation was performed under reduced pressure to obtain intermediate 2.

[0044] S3. Under nitrogen protection, add 28 g of intermediate 2, 7 mL of pyridine and 200 mL of dimethyl sulfoxide into a 500 mL dry brown three-necked flask, stir thoroughly until completely dissolved, then slowly add 6.8 mL of 2-methylene-1,3-propanediol, stir and heat to 50°C, keep warm and react for 3 hours. After the reaction is completed, cool to room temperature, distill under reduced pressure, purify by column chromatography (a mixed solvent of chloroform and acetone is selected as the eluent, and the volume ratio of chloroform and acetone is 17:3), and distill under reduced pressure to obtain a flame retardant.

[0045] Example 3: Preparation of PE power pipe, the specific steps are as follows:

[0046] The raw materials were weighed in parts by weight, and 100 parts of polyethylene, 15 parts of the filler prepared in Example 1, 10 parts of the flame retardant prepared in Example 2, 3 parts of dibutyl phthalate, 1 part of stearic acid, 0.5 parts of ultraviolet absorber UV-326, 0.5 parts of antioxidant 1076, and 0.01 parts of dicumyl peroxide were added to a high-speed mixer and mixed evenly. The mixture was then put into an internal mixer and melt-blended at 200°C for 15 minutes. Finally, the mixture was introduced into a plastic pipe processing equipment for extrusion, and the processing temperature range was controlled to be 190°C. After cooling, molding, and cutting, a PE power pipe was obtained.

[0047] Example 4: Preparation of PE power pipe, the specific steps are as follows:

[0048] The raw materials were weighed in parts by weight, and 100 parts of polyethylene, 20 parts of the filler prepared in Example 1, 13 parts of the flame retardant prepared in Example 2, 3 parts of epoxy soybean oil, 2 parts of diisononyl phthalate, 1 part of stearic acid, 0.5 parts of butyl stearate, 0.5 parts of ultraviolet absorber UV-326, 0.5 parts of ultraviolet absorber UV-3638, 0.5 parts of antioxidant 1076, 0.5 parts of antioxidant 1035, and 0.05 parts of dibenzoyl peroxide were added to a high-speed mixer and mixed evenly. The mixture was then put into an internal mixer and melt-blended at 210°C for 10 minutes. Finally, the mixture was introduced into a plastic pipe processing equipment for extrusion, and the processing temperature range was controlled to be 220°C. After cooling, molding, and cutting, a PE power pipe was obtained.

[0049] Example 5: Preparation of PE power pipe, the specific steps are as follows:

[0050] Each raw material was weighed by weight, and 100 parts of polyethylene, 25 parts of the filler prepared in Example 1, 15 parts of the flame retardant prepared in Example 2, 2 parts of epoxy soybean oil, 2 parts of dibutyl phthalate, 2 parts of diisononyl phthalate, 0.5 parts of stearic acid, 0.5 parts of butyl stearate, 1 part of ethylene bisstearamide, 1 part of ultraviolet absorber UV-326, 0.5 parts of ultraviolet absorber UV-3638, 0.5 parts of ultraviolet absorber UV-531, 1 part of antioxidant 1076, 0.5 parts of antioxidant 1035, 0.5 parts of antioxidant 1010, and 0.1 parts of di(2-ethylhexyl) peroxydicarbonate were added to a high-speed mixer and mixed evenly. The mixture was then put into an internal mixer and melt-blended at 205°C for 11 minutes. Finally, the mixture was introduced into a plastic pipe processing equipment for extrusion, and the processing temperature range was controlled to be 210°C. After cooling, molding, and cutting, a PE power pipe was obtained.

[0051] Comparative Example 1: Prepare the filler in the following steps:

[0052] The remaining steps remained unchanged, except that step (1) of Example 1 was removed and the modified coupling agent in step (2) was replaced by silane coupling agent KH540 to prepare the filler.

[0053] Comparative Example 2: Prepare filler. The specific steps are as follows:

[0054] The filler was prepared by fully mixing 12 g of rutile titanium dioxide, 8 g of heavy calcium carbonate, and 12 g of aluminum oxide.

[0055] Comparative Example 3: PE power pipe was prepared in the following steps:

[0056] The remaining steps remained unchanged, only the filler in Example 3 was replaced by the filler in Comparative Example 1 to prepare a PE power pipe.

[0057] Comparative Example 4: PE power pipe was prepared in the following steps:

[0058] The remaining steps remained unchanged, only the filler in Example 3 was replaced by the filler in Comparative Example 2 to prepare a PE power pipe.

[0059] Comparative Example 5: PE power pipe was prepared in the following steps:

[0060] The remaining steps remained unchanged, except that the flame retardant in Example 3 was replaced by 5 parts of Dow Corning silicone flame retardant FCA-107 and 5 parts of ammonium polyphosphate to prepare a PE power pipe.

[0061] Performance Testing

[0062] The power tubes prepared in Example 3-5 and Comparative Example 3-5 were made into test pieces that met the specifications according to different standards, and the following performance tests were performed:

[0063] The oxygen index was tested according to GB / T2406-93 "Plastics - Test Method for Combustion Performance - Oxygen Index Method"; the tensile strength was tested according to GB / T1040-2006 "Plastics - Determination of Tensile Properties"; and the Vicat softening temperature was tested according to GB / T1633-2000 "Thermoplastics - Determination of Vicat Softening Temperature". The test results for all items are shown in the following table:

[0064] Test items Oxygen index / % Tensile strength / MPa Vicat softening temperature / ℃ Example 3 39.7 41.2 117 Example 4 40.1 41.6 119 Example 5 40.3 42.8 121 Comparative Example 3 39.4 39.9 111 Comparative Example 4 38.9 36.4 105 Comparative Example 5 32.8 38.1 112

[0065] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0066] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A high temperature resistant PE power pipe, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of polyethylene, 15-25 parts of filler, 10-15 parts of flame retardant, 3-6 parts of plasticizer, 1-2 parts of lubricant, 0.5-2 parts of ultraviolet absorber, 0.5-2 parts of antioxidant, and 0.01-0.1 parts of initiator; Wherein, the filler is prepared by the following steps: (1) Add hydroxymethyltriethoxysilane, maleic anhydride, DMAP and chloroform to a flask under nitrogen protection, stir and heat to 50°C for 12 hours, cool, distill under reduced pressure, purify by column chromatography, and distill under reduced pressure to obtain a modified coupling agent; (2) Add titanium dioxide, heavy calcium carbonate, aluminum oxide, and anhydrous ethanol to a flask, stir evenly, and then add acetic acid to adjust the pH to 4; disperse the modified coupling agent in deionized water under nitrogen protection, stir, transfer to the above flask, heat to 65°C, react for 1 hour, cool, centrifuge, take the precipitate, ultrasonically disperse it in anhydrous ethanol, and dry it to obtain a filler; The flame retardant is prepared by the following steps: S1. Tris(2-chloroethyl) phosphate, triethylamine, and toluene were added to a flask under nitrogen, stirred, and bis(trimethylsilylmethyl)amine was added. The temperature was raised to 60°C and the reaction was carried out for 4 hours. The mixture was cooled and evaporated under reduced pressure. The mixture was purified by column chromatography and evaporated under reduced pressure to obtain intermediate 1. The amount ratio of tris(2-chloroethyl) phosphate, bis(trimethylsilylmethyl)amine, triethylamine and toluene in step S1 is 31 mL:59 g:25 mL:240 mL; the amount ratio of intermediate 1, 2-amino-4,6-dichloro-S-triazine, triethylamine and dimethyl sulfoxide in step S2 is 59 g:17 g:16 mL:250 mL; the amount ratio of intermediate 2, 2-methylene-1,3-propanediol, pyridine and dimethyl sulfoxide in step S3 is 28 g:6.8 mL:7 mL:200 mL; S2. Under nitrogen protection, intermediate 1, triethylamine and dimethyl sulfoxide were added to a flask, stirred, 2-amino-4,6-dichloro-S-triazine was added, the temperature was raised to 70°C, the reaction was continued for 5 hours, cooled, distilled under reduced pressure, purified by column chromatography, and distilled under reduced pressure to obtain intermediate 2; S3. Under nitrogen protection, add intermediate 2, pyridine and dimethyl sulfoxide into a flask, stir, add 2-methylene-1,3-propanediol, heat to 50°C and react for 3 hours, cool, distill under reduced pressure, purify by column chromatography, and distill under reduced pressure to obtain a flame retardant.

2. A high temperature resistant PE power pipe according to claim 1, characterized in that: The amount ratio of hydroxymethyltriethoxysilane, maleic anhydride, DMAP and chloroform in step (1) is 19g:10.4g:0.6g:200mL; the mass ratio of titanium dioxide, heavy calcium carbonate and aluminum oxide in step (2) is 3:2:3; the titanium dioxide in step (2) is rutile titanium dioxide.

3. The high temperature resistant PE power pipe according to claim 1, characterized in that: The mass ratio of the total mass of the titanium dioxide, heavy calcium carbonate and aluminum oxide to the mass of the modified coupling agent is 16:

1.

4. The high temperature resistant PE power pipe according to claim 1, characterized in that: The plasticizer is one or more of epoxy soybean oil, dibutyl phthalate, and diisononyl phthalate.

5. The high temperature resistant PE power pipe according to claim 1, characterized in that: The lubricant is one or more of stearic acid, butyl stearate, and ethylene bisstearamide.

6. The high temperature resistant PE power pipe according to claim 1, characterized in that: The ultraviolet absorber is one or more of ultraviolet absorber UV-326, ultraviolet absorber UV-3638, and ultraviolet absorber UV-531.

7. The high temperature resistant PE power pipe according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 1076, antioxidant 1035, and antioxidant 1010.

8. The high temperature resistant PE power pipe according to claim 1, characterized in that: The initiator is one or more of di(2-ethylhexyl) peroxydicarbonate, dibenzoyl peroxide, and dicumyl peroxide.

9. The method for preparing a high temperature resistant PE power pipe according to claim 1, characterized in that: The following steps are involved: Weigh each raw material by weight, add each raw material into a high-speed mixer and mix evenly, then put it into an internal mixer for melt blending, finally introduce it into a plastic pipe processing equipment for extrusion, cool and shape, and cut to produce a high-temperature resistant PE power pipe.

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