An MPP cable protection pipe and its preparation method

Abstract

This invention belongs to the field of cable protection conduits and discloses an MPP cable protection conduit and its preparation method, which is made from the following raw materials in parts by weight: 80-90 parts of random copolymer polypropylene, 3-6 parts of poly-1-butene, 4-8 parts of organically modified montmorillonite, 4-7 parts of maleic anhydride-grafted ethylene propylene diene monomer (EPDM-g-MAH), 1-2.5 parts of epoxidized soybean oil, 0.2-0.4 parts of antioxidant 1010, 0.15-0.3 parts of antioxidant 168, 0.2-0.5 parts of hindered amine light stabilizer 944, 0.4-0.8 parts of polyethylene wax, 3-6 parts of composite filler, and 2-5 parts of composite modifier. The purpose of this invention is to overcome the shortcomings of insufficient overall performance of existing MPP cable protection conduits, and to provide an MPP cable protection conduit and its preparation method that improves the internal structural density and interfacial bonding effect of the conduit, thereby enhancing the overall performance of the conduit.

Description

Technical Field

[0001] This invention relates to the field of cable protection pipe technology, specifically to an MPP cable protection pipe and its preparation method. Background Technology

[0002] MPP (modified polypropylene) cable protection conduits possess advantages such as high temperature resistance, high pressure resistance, corrosion resistance, light weight, and convenient construction, and are widely used in power, telecommunications, and other fields to protect underground cables from external damage and environmental erosion, ensuring the safe and stable operation of the cables. However, existing MPP cable protection conduits still have many shortcomings in their overall performance, failing to meet the requirements of complex working conditions in actual engineering projects. This technical solution proposes improvements to address these performance deficiencies, resolving the pain points of existing technologies and achieving superior technical results.

[0003] The core defects of existing MPP cable protection conduit materials are mainly reflected in five aspects: First, the ring stiffness is insufficient. When buried underground for a long time, it is prone to deformation and collapse under the action of external forces such as soil pressure and ground load, which cannot effectively support and protect the internal cables and can easily lead to cable damage under pressure. Secondly, the pipe has poor low-temperature toughness. In cold regions or low-temperature environments, the pipe becomes more brittle and is prone to cracking and damage from slight external impacts, affecting construction safety and service life. Third, the anti-aging performance is limited. When exposed to underground humid environments, ultraviolet radiation, or chemical media for a long time, the pipes are prone to aging, brittleness, degradation, etc., which leads to a significant decrease in mechanical properties and a shortened service life. Fourth, it has insufficient wear resistance and impact resistance. During construction, it is easily damaged by external forces such as dragging and collision. Moreover, long-term burial in the ground makes it susceptible to friction and wear from soil particles, resulting in thinner pipe walls and reduced strength. Fifth, it has poor dimensional stability and is prone to thermal expansion and contraction due to temperature changes, which can lead to loosening of pipe joints, reduced sealing performance, and problems such as water and mud ingress, which can then corrode the internal cables and affect their safe operation.

[0004] In view of the comprehensive performance defects of the existing MPP cable protection pipe body, the core technical problem to be solved by this technical solution is: to provide an MPP cable protection pipe body with excellent comprehensive performance and its preparation method, to solve the problems of insufficient ring stiffness, poor low temperature toughness, weak aging resistance, poor wear and impact resistance, and poor dimensional stability of the existing pipe body, to improve the structural strength, environmental adaptability and service life of the pipe body, and to reduce production costs and improve production efficiency. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of insufficient overall performance of MPP cable protection pipes in the prior art, and to provide an MPP cable protection pipe and its preparation method, which improves the internal structural density and interface bonding effect of the pipe and enhances the overall performance of the pipe.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The technical solution provided by this invention is: An MPP cable protection conduit is made from the following raw materials in parts by weight: 80-90 parts random copolymer polypropylene, 3-6 parts poly-1-butene, 4-8 parts organically modified montmorillonite, 4-7 parts maleic anhydride-grafted ethylene propylene diene monomer (EPDM-g-MAH), 1-2.5 parts epoxidized soybean oil, 0.2-0.4 parts antioxidant 1010, 0.15-0.3 parts antioxidant 168, 0.2-0.5 parts hindered amine light stabilizer 944, 0.4-0.8 parts polyethylene wax, 3-6 parts composite filler, and 2-5 parts composite modifier.

[0007] The random copolymer polypropylene has a melt index of 0.8–2.5 g / 10 min at 230°C and 2.16 kg. The organically modified montmorillonite is sodium montmorillonite modified with octadecyltrimethylammonium chloride, with a lamellar spacing ≥2.5 nm. It is prepared by modifying sodium montmorillonite and octadecyltrimethylammonium chloride at a mass ratio of 100:3–5. The sodium montmorillonite needs to be dried at 105–115°C for 2–3 hours to remove surface free water, and the octadecyltrimethylammonium chloride aqueous solution has a mass fraction of 1.5%–2.5%. The modification method of the organically modified montmorillonite is as follows: the sodium montmorillonite is placed in… Dry the sample in an oven at 105–115°C for 2–3 hours to remove surface free water and cool it to room temperature. Then, add it to an aqueous solution of 1.5%–2.5% (by mass) of octadecyltrimethylammonium chloride, wherein the mass ratio of sodium montmorillonite to octadecyltrimethylammonium chloride is 100:3–5. After stirring evenly, place the sample in a water bath at 60–70°C and stir at 300–400 r / min for 2–3 hours. After the reaction is complete, filter the sample and wash the filter cake with deionized water until the conductivity of the washing liquid is ≤50 μ / cm. Then, dry the filter cake in an oven at 80–90°C until constant weight, grind it, and pass it through a 200-mesh sieve to obtain the final product.

[0008] The grafting rate of the maleic anhydride-grafted EPDM rubber is 0.6%–1.2%; the composite filler is a multi-component composite material, composed of fly ash, carbon black, and polyethylene glycol in a mass ratio of 4:2:1, wherein the fly ash is 800–1000 mesh, the carbon black is N330 type, and the polyethylene glycol has a molecular weight of 4000–6000; the preparation method of the composite filler is as follows: weigh fly ash, carbon black, and polyethylene glycol according to the above mass ratio, put them into a high-speed mixer, mix them for 12–18 minutes at 90–110℃ and 800–1000 r / min, and then cool them to room temperature to obtain the filler.

[0009] The composite modifier is a multi-component composite material, composed of maleic anhydride-grafted POE, polylactic acid, and nano-silica in a mass ratio of 3:2:1. The grafting rate of maleic anhydride-grafted POE is 0.7%–1.3%, the weight-average molecular weight of polylactic acid is 80,000–120,000, and the particle size of nano-silica is 20–50 nm. The preparation method of the composite modifier is as follows: weigh each component according to the above mass ratio, put them into a twin-screw mixer, melt-blend at 160–180℃ and 300–380 r / min for 8–12 min, extrude and granulate, cool to room temperature, and pulverize to 80–100 mesh to obtain the final product.

[0010] The present invention also provides a method for preparing the above-mentioned MPP cable protection conduit, comprising the following steps: S1: Weigh each raw material according to the weight parts, first put the organic modified montmorillonite and epoxidized soybean oil into a high-speed mixer, mix at 60-80℃ for 5-8 minutes to complete the pretreatment of filler activation; S2: Take the composite filler and composite modifier separately and put them into a high-speed mixer together. Mix them with the pretreated material from step S1 for 3-5 minutes to obtain a composite modified mixture. The composite filler is composed of fly ash, carbon black and polyethylene glycol in a mass ratio of 4:2:1. The preparation method is as follows: weigh fly ash, carbon black and polyethylene glycol in a mass ratio of 4:2:1, put them into a high-speed mixer, mix them at 90-110℃ and 800-1000 r / min for 12-18 minutes, and cool them to room temperature. The composite modifier is composed of maleic anhydride grafted POE, polylactic acid and nano silica in a mass ratio of 3:2:1. The preparation method is as follows: weigh each component in a mass ratio of 3:2:1, put them into a twin-screw mixer, melt-blend them at 160-180℃ and 300-380 r / min for 8-12 minutes, extrude and granulate them, cool them to room temperature, and pulverize them to 80-100 mesh. S3: Add random copolymer polypropylene, poly-1-butene, maleic anhydride-grafted EPDM rubber, antioxidant 1010, antioxidant 168, light stabilizer 944, and polyethylene wax to the mixer, and continue mixing at room temperature for 8-10 minutes to obtain a uniform mixture. S4: Add the mixture to a twin-screw extruder, melt extrude and granulate to obtain MPP-specific modified material; wherein, the temperature of each section of the twin-screw extruder is: 175~185℃, 185~195℃, 195~205℃, 200~210℃, and the screw speed is 280~360r / min. S5: The modified material is extruded and shaped by a single screw extruder, vacuum sizing, cooling, traction, and length cutting to obtain the MPP cable protection pipe; wherein, the temperature of the single screw extruder is 195~215℃, the vacuum sizing pressure is 0.025~0.04MPa, and the cooling water temperature is 20~28℃.

[0011] The beneficial effects of this technical solution are: (1) This technical solution uses random copolymer polypropylene as the base material, combined with an appropriate amount of poly-1-butene. The synergistic effect of the two can optimize the processing fluidity and molding stability of the base material, avoid the problem of high brittleness and easy defects in molding of single polypropylene base material, and lay the foundation for the overall structural strength of the pipe. The addition of organic modified montmorillonite can improve the mechanical properties of the base material. After specific modification treatment, it can be better dispersed in the base material system, form a good interface bond with the base material, and enhance the deformation resistance and toughness of the pipe, which is different from the disadvantage of uneven dispersion of unmodified montmorillonite.

[0012] (2) The composite system of composite filler and composite modifier is one of the core advantages of this technology, and the two work synergistically to enhance each other's effectiveness. The composite filler is composed of fly ash, carbon black and polyethylene glycol, which can not only supplement the structural strength of the pipe, but also improve the wear resistance and dimensional stability of the pipe. Compared with single filler, it can better meet the performance requirements of multiple aspects. The composite modifier is composed of maleic anhydride grafted POE, polylactic acid and nano silica, which can improve the compatibility between the raw materials, improve the low temperature toughness and anti-aging ability of the pipe, and solve the problems of uneven dispersion of different components and poor interfacial bonding.

[0013] (3) Maleic anhydride-grafted EPDM rubber can further enhance the impact resistance of the pipe. Epoxidized soybean oil can improve the dispersibility of fillers and the compatibility between raw materials. Combined with antioxidants and light stabilizers, it can effectively delay the aging of the pipe and extend its service life. Polyethylene wax can optimize the processing, avoid raw material adhesion, and ensure smooth molding. The proportions of each component are scientific and reasonable, with no redundant components, forming a synergistic and complementary overall system. Compared with single components or simple compounding, it can more comprehensively improve the overall performance of the pipe and meet the multifaceted needs of buried cable protection. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the preparation process of an MPP cable protection pipe and its preparation method proposed in this invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] The specific implementation process is as follows: Example 1:

[0017] Please see Figure 1 The present invention provides a technical solution: an MPP cable protection pipe, which is made from the following raw materials in actual weight parts: 80 parts of random copolymer polypropylene (melt index 0.8g / 10min at 230℃ and 2.16kg), 3 parts of poly-1-butene, 4 parts of organic modified montmorillonite, 4 parts of maleic anhydride-grafted EPDM rubber (grafting rate 0.6%), 1 part of epoxidized soybean oil, 0.2 parts of antioxidant 1010, 0.15 parts of antioxidant 168, 0.2 parts of hindered amine light stabilizer 944, 0.4 parts of polyethylene wax, 3 parts of composite filler, and 2 parts of composite modifier.

[0018] Its preparation method includes the following steps: S1: First, prepare organically modified montmorillonite. The specific preparation method is as follows: Dry sodium-based montmorillonite in a 110℃ oven for 2.5 hours to remove surface free water and cool to room temperature. Then, add it to an aqueous solution of 2.0% (by mass) octadecyltrimethylammonium chloride, wherein the mass ratio of sodium-based montmorillonite to octadecyltrimethylammonium chloride is 100:4. After stirring evenly, place it in a 65℃ water bath and stir at 350 r / min for 2.5 hours. After the reaction, filter, wash the filter cake with deionized water until the conductivity of the washing liquid is ≤50 μ / cm, and then dry the filter cake in an 85℃ oven to constant weight. Grind and pass through a 200-mesh sieve to obtain the product. The interlamellar spacing of this organically modified montmorillonite is 2.8 nm, which meets the requirements of the claims. Weigh each raw material according to the above actual weight parts, and put 4 parts of the prepared organically modified montmorillonite and 1 part of epoxidized soybean oil into a high-speed mixer and mix at 60℃ for 5 minutes to complete the pretreatment of the filler activation. S2: First, prepare the composite filler and composite modifier separately. The composite filler is prepared by weighing 800-mesh fly ash, N330 carbon black, and polyethylene glycol with a molecular weight of 5000 in a mass ratio of 4:2:1, adding them to a high-speed mixer, and mixing for 15 minutes at 100℃ and 900 r / min. After cooling to room temperature, the composite modifier is obtained. The composite modifier is prepared by weighing maleic anhydride-grafted POE with a grafting rate of 1.0%, polylactic acid with a weight average molecular weight of 100,000, and nano-silica with a particle size of 30 nm in a mass ratio of 3:2:1, adding them to a twin-screw mixer, and melting and blending for 10 minutes at 170℃ and 340 r / min. After extrusion granulation, cooling to room temperature, and pulverizing to 90 mesh, the composite filler and composite modifier are added to a high-speed mixer and mixed with the pretreated material from step S1 for 3 minutes to obtain the composite modified mixture. S3: Add 80 parts of random copolymer polypropylene, 3 parts of poly-1-butene, 4 parts of maleic anhydride-grafted EPDM rubber, 0.2 parts of antioxidant 1010, 0.15 parts of antioxidant 168, 0.2 parts of hindered amine light stabilizer 944, and 0.4 parts of polyethylene wax to the mixer, and continue mixing at room temperature for 8 minutes to obtain a uniform mixture; S4: Add the mixture to a twin-screw extruder, melt extrude and granulate to obtain MPP-specific modified material; wherein the temperatures of each section of the twin-screw extruder are: 175℃, 185℃, 195℃, 200℃, and the screw speed is 280 r / min. S5: The modified material is extruded and shaped by a single screw extruder, vacuum sizing, cooling, traction, and fixed-length cutting to obtain the MPP cable protection pipe; wherein, the temperature of the single screw extruder is 195℃, the vacuum sizing pressure is 0.025MPa, and the cooling water temperature is 20℃.

[0019] The experimental data above show that the MPP cable protection conduit prepared in Example 1 meets all industry standard requirements, and its core performance indicators are all better than the lower limit of the standard. Specifically, the ring stiffness reaches 8.2 kN / m. 2 It exceeds the standard requirement of 6.3 kN / m. 2 This indicates that the pipe has good resistance to deformation and can withstand soil pressure and ground loads for long-term underground burial; the low-temperature impact strength is 12.5 kJ / m. 2 It is far higher than the standard requirement of 8.0 kJ / m 2The results indicate that the pipe exhibits low brittleness and strong impact resistance in cold environments, making it less prone to cracking. In terms of anti-aging properties, the tensile strength retention rate reaches 88.6%, demonstrating the pipe's excellent resistance to ultraviolet radiation and degradation, which can extend its underground service life. The wear amount is only 0.032g, meeting the standard requirements, indicating excellent wear resistance and the ability to withstand soil particle friction. The dimensional change rate is 0.32%, lower than the standard upper limit, indicating good dimensional stability and minimal impact from temperature changes, ensuring reliable joint sealing. In summary, the pipe prepared in Example 1 demonstrates excellent overall performance, effectively addressing the core defects of existing pipe technologies. Example 2:

[0020] Please see Figure 1 The present invention provides a technical solution: an MPP cable protection pipe, made from the following raw materials in parts by weight: 85 parts of random copolymer polypropylene (melt index 1.6g / 10min at 230℃ and 2.16kg), 4.5 parts of poly-1-butene, 6 parts of organically modified montmorillonite, 5.5 parts of maleic anhydride-grafted EPDM rubber (grafting rate 0.9%), 1.75 parts of epoxidized soybean oil, 0.3 parts of antioxidant 1010, 0.225 parts of antioxidant 168, 0.35 parts of hindered amine light stabilizer 944, 0.6 parts of polyethylene wax, 4.5 parts of composite filler, and 3.5 parts of composite modifier.

[0021] Its preparation method includes the following steps: S1: First, prepare organically modified montmorillonite. The specific preparation method is as follows: Dry sodium-based montmorillonite in a 110℃ oven for 2.5 hours to remove surface free water and cool to room temperature. Then, add it to an aqueous solution of 2.0% (by mass) octadecyltrimethylammonium chloride, wherein the mass ratio of sodium-based montmorillonite to octadecyltrimethylammonium chloride is 100:4. After stirring evenly, place it in a 65℃ water bath and stir at 350 r / min for 2.5 hours. After the reaction, filter, wash the filter cake with deionized water until the conductivity of the washing liquid is ≤50 μ / cm, and then dry the filter cake in an 85℃ oven to constant weight. Grind and pass through a 200-mesh sieve to obtain the product. The interlamellar spacing of this organically modified montmorillonite is 2.8 nm, which meets the requirements of the claims. Weigh each raw material according to the above actual weight parts, and put 6 parts of the prepared organically modified montmorillonite and 1.75 parts of epoxidized soybean oil into a high-speed mixer and mix at 70℃ for 6.5 minutes to complete the pretreatment of the filler activation. S2: First, prepare the composite filler and composite modifier separately. The composite filler is prepared by weighing 900-mesh fly ash, N330 carbon black, and polyethylene glycol with a molecular weight of 5000 in a mass ratio of 4:2:1, adding them to a high-speed mixer, and mixing for 15 minutes at 100℃ and 900 r / min. After cooling to room temperature, the composite modifier is obtained. The composite modifier is prepared by weighing maleic anhydride-grafted POE with a grafting rate of 1.0%, polylactic acid with a weight average molecular weight of 100,000, and nano-silica with a particle size of 30 nm in a mass ratio of 3:2:1, adding them to a twin-screw mixer, and melting and blending for 10 minutes at 170℃ and 340 r / min. After extrusion granulation, cooling to room temperature, and pulverizing to 90 mesh, the composite filler and composite modifier are added to a high-speed mixer and mixed with the pretreated material from step S1 for 4 minutes to obtain the composite modified mixture. S3: Add 85 parts of random copolymer polypropylene, 4.5 parts of poly-1-butene, 5.5 parts of maleic anhydride-grafted EPDM rubber, 0.3 parts of antioxidant 1010, 0.225 parts of antioxidant 168, 0.35 parts of hindered amine light stabilizer 944, and 0.6 parts of polyethylene wax to the mixer, and continue mixing at room temperature for 9 minutes to obtain a uniform mixture; S4: Add the mixture to a twin-screw extruder, melt extrude and granulate to obtain MPP-specific modified material; wherein, the temperature of each section of the twin-screw extruder is: 180℃, 190℃, 200℃, 205℃, and the screw speed is 320r / min. S5: The modified material is extruded through a single screw extruder, vacuum sizing, cooled, drawn, and cut to a fixed length to obtain the MPP cable protection pipe; wherein, the temperature of the single screw extruder is 205℃, the vacuum sizing pressure is 0.0325MPa, and the cooling water temperature is 24℃.

[0022] The MPP cable protection conduit prepared in Example 2 showed significantly better performance in all aspects than that of Example 1 and the industry standard requirements, with outstanding performance in core indicators. Specifically, the ring stiffness reached 10.5 kN / m. 2 The value is far higher than the lower limit of the standard, indicating that the pipe has stronger resistance to deformation and collapse, and can adapt to more complex underground load environments; the low-temperature impact strength is 15.8 kJ / m. 2Compared to Example 1, the improvement is significant, indicating that the toughness and impact resistance of the pipe in low-temperature environments are further optimized, enabling stable use in cold regions. The tensile strength retention rate in anti-aging properties reaches 92.3%, demonstrating excellent UV and degradation resistance, effectively extending the service life underground. The wear amount is only 0.025g, with better wear resistance than Example 1, better resisting frictional loss from underground soil particles. The dimensional change rate is as low as 0.21%, exhibiting excellent dimensional stability, effectively avoiding problems such as loosening of joints and sealing failure caused by temperature changes. The tensile strength reaches 32.8MPa, far exceeding the standard requirements, indicating high structural strength and resistance to breakage. In summary, Example 2, using intermediate ratios and process parameters, achieves optimal overall performance of the pipe. Example 3:

[0023] Please see Figure 1 The present invention provides a technical solution: an MPP cable protection pipe, which is made from the following raw materials in actual weight parts: 90 parts of random copolymer polypropylene (melt index 2.5g / 10min at 230℃ and 2.16kg), 6 parts of poly-1-butene, 8 parts of organically modified montmorillonite, 7 parts of maleic anhydride-grafted EPDM rubber (grafting rate 1.2%), 2.5 parts of epoxidized soybean oil, 0.4 parts of antioxidant 1010, 0.3 parts of antioxidant 168, 0.5 parts of hindered amine light stabilizer 944, 0.8 parts of polyethylene wax, 6 parts of composite filler, and 5 parts of composite modifier.

[0024] Its preparation method includes the following steps: S1: First, prepare organically modified montmorillonite. The specific preparation method is as follows: Dry sodium-based montmorillonite in a 110℃ oven for 2.5 hours to remove surface free water and cool to room temperature. Then, add it to an aqueous solution of 2.0% (by mass) octadecyltrimethylammonium chloride, wherein the mass ratio of sodium-based montmorillonite to octadecyltrimethylammonium chloride is 100:4. After stirring evenly, place it in a 65℃ water bath and stir at 350 r / min for 2.5 hours. After the reaction, filter, wash the filter cake with deionized water until the conductivity of the washing liquid is ≤50 μ / cm, and then dry the filter cake in an 85℃ oven to constant weight. Grind and pass through a 200-mesh sieve to obtain the product. The interlamellar spacing of this organically modified montmorillonite is 2.8 nm, which meets the requirements of the claims. Weigh each raw material according to the above actual weight parts, and put 8 parts of the prepared organically modified montmorillonite and 2.5 parts of epoxidized soybean oil into a high-speed mixer and mix at 80℃ for 8 minutes to complete the pretreatment of the filler activation. S2: First, prepare the composite filler and composite modifier separately. The composite filler is prepared by weighing 1000-mesh fly ash, N330 carbon black, and polyethylene glycol with a molecular weight of 5000 in a mass ratio of 4:2:1, adding them to a high-speed mixer, and mixing for 15 minutes at 100℃ and 900 r / min. After cooling to room temperature, the composite modifier is obtained. The composite modifier is prepared by weighing maleic anhydride-grafted POE with a grafting rate of 1.0%, polylactic acid with a weight average molecular weight of 100,000, and nano-silica with a particle size of 30 nm in a mass ratio of 3:2:1, adding them to a twin-screw mixer, and melting and blending for 10 minutes at 170℃ and 340 r / min. After extrusion granulation, cooling to room temperature, and pulverizing to 90 mesh, the composite filler and composite modifier are added to a high-speed mixer and mixed with the pretreated material from step S1 for 5 minutes to obtain the composite modified mixture. S3: Add 90 parts of random copolymer polypropylene, 6 parts of poly-1-butene, 7 parts of maleic anhydride-grafted EPDM rubber, 0.4 parts of antioxidant 1010, 0.3 parts of antioxidant 168, 0.5 parts of hindered amine light stabilizer 944, and 0.8 parts of polyethylene wax to the mixer, and continue mixing at room temperature for 10 minutes to obtain a uniform mixture. S4: Add the mixture to a twin-screw extruder, melt extrude and granulate to obtain MPP-specific modified material; wherein, the temperature of each section of the twin-screw extruder is: 185℃, 195℃, 205℃, 210℃, and the screw speed is 360r / min. S5: The modified material is extruded and shaped by a single screw extruder, vacuum sizing, cooling, traction, and length cutting to obtain the MPP cable protection pipe; wherein, the temperature of the single screw extruder is 215℃, the vacuum sizing pressure is 0.04MPa, and the cooling water temperature is 28℃.

[0025] The MPP cable protection conduit prepared in Example 3 meets all industry standard requirements, and its overall performance is better than that of Example 1 but slightly lower than that of Example 2, consistent with the variation law of the mixing ratio and process parameters. The ring stiffness is 9.8 kN / m. 2 The results are higher than the standard requirements and those of Example 1, indicating that the pipe has strong resistance to deformation and can adapt to complex underground load environments; the low-temperature impact strength is 14.2 kJ / m. 2The results are significantly higher than the lower limit of the standard and superior to those of Example 1, indicating that the pipe exhibits good toughness and impact resistance in low-temperature environments, allowing for normal use in cold regions. The tensile strength retention rate in anti-aging properties reaches 90.7%, demonstrating excellent UV and degradation resistance, effectively extending the pipe's underground service life. The wear amount is 0.028g, with wear resistance superior to Example 1, effectively resisting frictional loss from underground soil particles. The dimensional change rate is 0.27%, indicating good dimensional stability and preventing issues such as loosening of joints and sealing failure caused by temperature changes. The tensile strength is 31.5MPa, far exceeding the standard requirements, indicating high structural strength and resistance to breakage. In summary, Example 3, using the upper limit ratio and process parameters, still stably produces pipes with excellent comprehensive performance, further verifying the wide applicability and stability of the present invention. Example 4:

[0026] Please see Figure 1 The present invention provides a technical solution: an MPP cable protection pipe, which is made from the following raw materials in parts by weight: 82 parts of random copolymer polypropylene (melt index 1.0g / 10min at 230℃ and 2.16kg), 5 parts of poly-1-butene, 5 parts of organically modified montmorillonite, 6 parts of maleic anhydride-grafted EPDM rubber (grafting rate 0.7%), 1.5 parts of epoxidized soybean oil, 0.25 parts of antioxidant 1010, 0.18 parts of antioxidant 168, 0.3 parts of hindered amine light stabilizer 944, 0.5 parts of polyethylene wax, 5 parts of composite filler, and 4 parts of composite modifier.

[0027] Its preparation method includes the following steps: S1: First, prepare organically modified montmorillonite. The specific preparation method is as follows: Dry sodium-based montmorillonite in a 110℃ oven for 2.5 hours to remove surface free water and cool to room temperature. Then, add it to an aqueous solution of 2.0% (by mass) octadecyltrimethylammonium chloride, wherein the mass ratio of sodium-based montmorillonite to octadecyltrimethylammonium chloride is 100:4. After stirring evenly, place it in a 65℃ water bath and stir at 350 r / min for 2.5 hours. After the reaction, filter, wash the filter cake with deionized water until the conductivity of the washing liquid is ≤50 μ / cm, and then dry the filter cake in an 85℃ oven to constant weight. Grind and pass through a 200-mesh sieve to obtain the product. The interlamellar spacing of this organically modified montmorillonite is 2.8 nm, which meets the requirements of the claims. Weigh each raw material according to the above actual weight parts, and put 5 parts of the prepared organically modified montmorillonite and 1.5 parts of epoxidized soybean oil into a high-speed mixer and mix at 65℃ for 7 minutes to complete the pretreatment of the filler activation. S2: First, prepare the composite filler and composite modifier separately. The composite filler is prepared by weighing 850-mesh fly ash, N330 carbon black, and polyethylene glycol with a molecular weight of 4000 in a mass ratio of 4:2:1, adding them to a high-speed mixer, and mixing for 16 minutes at 95℃ and 850 r / min. After cooling to room temperature, the composite modifier is obtained. The composite modifier is prepared by weighing maleic anhydride-grafted POE with a grafting rate of 0.7%, polylactic acid with a weight average molecular weight of 80,000, and nano-silica with a particle size of 20 nm in a mass ratio of 3:2:1, adding them to a twin-screw mixer, and melting and blending for 11 minutes at 165℃ and 320 r / min. After extrusion granulation, cooling to room temperature, and pulverizing to 80 mesh, the composite filler and composite modifier are added to a high-speed mixer and mixed with the pretreated material from step S1 for 4.5 minutes to obtain the composite modified mixture. S3: Add 82 parts of random copolymer polypropylene, 5 parts of poly-1-butene, 6 parts of maleic anhydride-grafted EPDM rubber, 0.25 parts of antioxidant 1010, 0.18 parts of antioxidant 168, 0.3 parts of hindered amine light stabilizer 944, and 0.5 parts of polyethylene wax to the mixer, and continue mixing at room temperature for 8.5 minutes to obtain a uniform mixture; S4: Add the mixture to a twin-screw extruder, melt extrude and granulate to obtain MPP-specific modified material; wherein, the temperature of each section of the twin-screw extruder is: 178℃, 188℃, 198℃, 202℃, and the screw speed is 300r / min. S5: The modified material is extruded into shape by a single screw extruder, vacuum sizing, cooling, traction, and fixed-length cutting to obtain the MPP cable protection pipe; wherein, the temperature of the single screw extruder is 200℃, the vacuum sizing pressure is 0.03MPa, and the cooling water temperature is 22℃.

[0028] Example 4 uses raw materials with different parameters within a defined range, and adjusts the proportions and process parameters. The resulting MPP cable protection pipe still meets all industry standard requirements, and its overall performance is better than Example 1, but slightly lower than Examples 2 and 3, demonstrating the flexibility and stability of the technical solution of this invention. The ring stiffness is 9.1 kN / m. 2 The results are higher than the standard requirements and those of Example 1, indicating that the pipe has good resistance to deformation and can adapt to complex underground load environments; the low-temperature impact strength is 13.7 kJ / m. 2The results, far exceeding the lower limit of the standard, indicate that the pipe exhibits good toughness and impact resistance in low-temperature environments, allowing for normal use in cold regions. The tensile strength retention rate in the anti-aging properties reaches 89.5%, demonstrating the pipe's excellent resistance to ultraviolet radiation and degradation, effectively extending its underground service life. The wear amount is 0.030g, with wear resistance superior to Example 1, effectively resisting frictional loss from underground soil particles. The dimensional change rate is 0.29%, indicating good dimensional stability and preventing problems such as loosening of joints and sealing failure caused by temperature changes. The tensile strength is 30.2MPa, far exceeding the standard requirements, indicating high structural strength and resistance to breakage. In summary, Example 4 further verifies the flexibility of the present invention's technical solution. As long as the raw material parameters, proportions, and process parameters are within the scope defined in the claims, regardless of their specific values, pipes with excellent comprehensive performance can be stably prepared.

[0029] Comparative Example 1: Please see Figure 1 The present invention provides a comparative scheme, which differs from Example 2 in that: no composite filler or composite modifier is used; the sodium-based montmorillonite is not modified, and ordinary sodium-based montmorillonite is used directly; only the basic components are retained in the raw materials, and there is no composite system as defined in this invention. The remaining raw material ratios and preparation process parameters are completely consistent with those of Example 2.

[0030] Comparative Example 1, lacking the addition of composite fillers and composite modifiers, and directly using unmodified ordinary sodium-based montmorillonite, did not possess the composite system defined in this invention. Therefore, its performance was only slightly above the lower limit of industry standards, showing a significant difference compared to Example 2. The ring stiffness was only 6.5 kN / m. 2 Its resistance to deformation is significantly reduced, making it difficult to adapt to complex underground loads; its low-temperature impact strength is 8.2 kJ / m. 2 It exhibits poor low-temperature toughness and is prone to cracking in cold environments; its anti-aging properties, wear resistance, dimensional stability, and tensile strength are all close to the standard critical values, and long-term use is prone to performance degradation, damage, and loosening of joints. This comparative example fully demonstrates that the composite filler, composite modifier, and organically modified montmorillonite specified in this invention are the core components for improving the overall performance of MPP cable protection pipes, and none of them can be omitted.

[0031] Comparative Example 2: Please see Figure 1 The present invention provides a comparative scheme, which differs from Example 2 in that: no composite filler is used, only the composite modifier is retained; the remaining raw material ratios, organic modified montmorillonite preparation methods, and preparation process parameters are completely consistent with Example 2.

[0032] Comparative Example 2, retaining only the composite modifier and without adding composite filler, showed superior performance in all aspects compared to Comparative Example 1, but significantly lower performance than Example 2. Its ring stiffness was 7.8 kN / m. 2 It has insufficient resistance to deformation and is unable to withstand large underground loads; its low-temperature impact strength is 11.3 kJ / m. 2 The low-temperature toughness decreased significantly compared to Example 2; the wear resistance and tensile strength also decreased significantly. The main reason is the lack of reinforcement and wear resistance from the composite filler, which prevents it from forming a synergistic effect with the composite modifier. This comparative example demonstrates that the composite filler is the key to improving the strength, wear resistance, and dimensional stability of the pipe. The composite modifier alone cannot achieve the optimal improvement of the overall performance of the pipe. The composite system of this invention (composite filler + composite modifier) ​​is indispensable.

[0033] Comparative Example 3: Please see Figure 1 The present invention provides a comparative scheme, which differs from Example 2 in that: no composite modifier is used, only the composite filler is retained; the remaining raw material ratios, organic modified montmorillonite preparation methods, and preparation process parameters are completely consistent with Example 2.

[0034] Comparative Example 3 retained only the composite filler and did not add the composite modifier. Its performance was superior to Comparative Example 1 and slightly superior to Comparative Example 2, but still far inferior to Example 2. Specifically, its low-temperature impact strength was only 9.7 kJ / m. 2 The pipe exhibits significant low-temperature brittleness and insufficient impact resistance, primarily due to the lack of toughening and compatibility enhancement from the composite modifier, which fails to improve the interfacial bonding between raw materials. Anti-aging properties and dimensional stability also show a marked decline, failing to achieve synergistic effects among the raw materials. This comparative example further demonstrates that the composite modifier is crucial for improving the pipe's toughness, compatibility, and anti-aging properties. Relying solely on composite fillers cannot meet the performance requirements of this invention; the synergistic effect of composite fillers and composite modifiers is one of the core advantages of this invention.

[0035] Comparative Example 4: Please see Figure 1 The present invention provides a comparative scheme, which differs from Example 2 in that: the organic modification method of montmorillonite is different, using a 1.0% (w / w) hexadecyltrimethylammonium bromide aqueous solution for modification, the modification temperature is 55°C, the reaction time is 1.5 h, and the remaining modification steps remain unchanged; the interlayer spacing of the obtained montmorillonite is 1.9 nm, which does not meet the requirements of the claims of the present invention; the remaining raw material ratios and preparation process parameters are completely consistent with those of Example 2.

[0036] Comparative Example 4, due to the use of an organically modified montmorillonite modification method that does not meet the requirements of this invention, resulted in montmorillonite with a lamellar spacing of only 1.9 nm, leading to poor modification effects. Consequently, all properties were lower than those of Example 2 and slightly lower than those of Comparative Example 3. Insufficient lamellar spacing prevents effective dispersion of montmorillonite within the raw material system, hindering its reinforcing and toughening effects. This results in a decrease in pipe ring stiffness, tensile strength, and low-temperature impact strength. Simultaneously, the interfacial bonding between montmorillonite and other raw materials deteriorates, affecting wear resistance and dimensional stability. This comparative example demonstrates that the organically modified montmorillonite preparation method (specific modifier, temperature, and time) specified in this invention is crucial for ensuring the modification effect of montmorillonite and improving the overall performance of the pipe. Deviating from this method leads to a significant performance decline.

[0037] Comparative Example 5: Please see Figure 1 The present invention provides a comparative scheme: the difference from Example 2 is that the preparation process does not include the filler activation pretreatment in step S1, and all raw materials are directly put into the mixer for mixing; the remaining raw material ratios, organic modified montmorillonite preparation methods, composite filler and composite modifier preparation methods, and process parameters are completely consistent with Example 2.

[0038] Comparative Example 5 omitted the filler activation pretreatment step S1, directly mixing all raw materials. This resulted in insufficient activation of the organically modified montmorillonite and composite filler, leading to poor dispersibility and interfacial bonding with other raw materials, and all performance characteristics were lower than in Example 2. Without activation pretreatment, the filler lacked surface activity, making it prone to agglomeration and failing to fully exert its reinforcing, toughening, and wear-resistant effects, resulting in a decrease in pipe ring stiffness, tensile strength, and wear resistance. Simultaneously, uneven raw material dispersion also affected the dimensional stability and anti-aging properties of the pipe. This comparative example demonstrates that the filler activation pretreatment step specified in this invention is a necessary process to ensure uniform raw material dispersion and improve the overall performance of the pipe. Omitting this step leads to a significant performance decline, further highlighting the rationality and necessity of the process in this invention.

[0039] Comparative Example 6: Please see Figure 1 The present invention provides a comparative scheme, which differs from Example 2 in that: a single 800-mesh fly ash is used to replace the composite filler (the amount is the same as that in Example 2), and a single maleic anhydride grafted with POE with a grafting rate of 1.0% is used to replace the composite modifier (the amount is the same as that in Example 2); the remaining raw material ratios, organic modified montmorillonite preparation methods, and preparation process parameters are completely consistent with Example 2.

[0040] Comparative Example 6, using a single raw material to replace the composite filler and composite modifier of the present invention, showed lower performance in all aspects compared to Example 2, and slightly lower than Comparative Example 3, but higher than Comparative Examples 2 and 4. Single fly ash could not achieve the synergistic effects of reinforcement, wear resistance, and dimensional stability of the composite filler, and single maleic anhydride-grafted POE could not achieve the synergistic effects of toughening, compatibility, and anti-aging of the composite modifier, resulting in varying degrees of decline in the pipe's performance. Among these, the low-temperature impact strength and anti-aging performance showed the most significant decline, failing to meet the requirements for use in complex environments. This comparative example fully demonstrates that the composite filler (multi-component synergy) and composite modifier (multi-component synergy) used in the present invention have significant advantages over single raw materials. The synergistic effect of multiple components is the core of improving the overall performance of the pipe and is also one of the key differences between the present invention and existing technologies.

[0041] This technical solution uses random copolymer polypropylene as the base material, combined with an appropriate amount of poly-1-butene. The synergistic effect of the two optimizes the processing fluidity and molding stability of the base material, avoiding the problems of high brittleness and easy defects in molding of single polypropylene base material, thus laying the foundation for the overall structural strength of the pipe. The addition of organically modified montmorillonite can improve the mechanical properties of the base material. After specific modification treatment, it can be better dispersed in the base material system, forming a good interfacial bond with the base material, enhancing the pipe's resistance to deformation and toughness, which is different from the disadvantage of uneven dispersion of unmodified montmorillonite.

[0042] The composite system of composite filler and composite modifier is one of the core advantages of this technology, with the two working synergistically to enhance performance. The composite filler is composed of fly ash, carbon black, and polyethylene glycol, which not only supplements the structural strength of the pipe but also improves its wear resistance and dimensional stability, thus better meeting multiple performance requirements compared to a single filler. The composite modifier is composed of maleic anhydride-grafted POE, polylactic acid, and nano-silica, which improves the compatibility between the raw materials, enhances the low-temperature toughness and anti-aging ability of the pipe, and solves the problems of uneven dispersion and poor interfacial bonding of different components.

[0043] Maleic anhydride-grafted EPDM rubber further enhances the pipe's impact resistance, while epoxidized soybean oil improves filler dispersibility and compatibility with raw materials. Combined with antioxidants and light stabilizers, it effectively delays pipe aging and extends service life. Polyethylene wax optimizes the processing, prevents raw material adhesion, and ensures smooth molding. The scientifically proportioned ingredients, with no redundant components, form a synergistic and complementary system. Compared to single-component or simple compounding, this system more comprehensively improves the overall performance of the pipe, meeting the diverse needs of buried cable protection.

[0044] Based on the comparative analysis of all the above embodiments and comparative examples, Examples 1 to 4 all use random copolymer polypropylene and poly-1-butene as the base material, combined with a composite system of specifically modified organic montmorillonite, composite filler and composite modifier, and supplemented with auxiliary components such as maleic anhydride-grafted EPDM rubber and epoxidized soybean oil. The components work synergistically and complementarily to solve the core defects of MPP pipes in the prior art, such as high brittleness, weak deformation resistance, poor wear resistance, insufficient low-temperature toughness and poor anti-aging performance.

[0045] Comparative Example 1 lacked composite filler and composite modifier and did not use modified montmorillonite. Its performance was only close to the lower limit of industry standards, highlighting the core role of the composite system and modified montmorillonite in this technical solution. Comparative Examples 2 and 3 lacked composite filler and composite modifier, respectively. Their performance was significantly lower than that of Example 2, proving that the synergistic effect of composite filler and composite modifier is the key to improving the overall performance of the pipe. Both are indispensable. Comparative Example 4 used a montmorillonite modification method that did not meet the requirements of this technology, resulting in poor montmorillonite modification effect and a significant decrease in performance. This proves that the montmorillonite modification method specified in this technology is a necessary condition to ensure the modification effect and improve the performance of the pipe. Comparative Example 5 omitted the filler activation pretreatment step, resulting in uneven dispersion of raw materials and decreased performance, highlighting the rationality and necessity of the process steps in this technology. Comparative Example 6 used a single raw material to replace composite filler and composite modifier, which could not achieve the synergistic effect of multiple components. Its performance was far lower than that of Example 2, proving that the composite system used in this technology has significant advantages over single raw material compounding and breaks the limitations of single component or simple compounding in the prior art.

[0046] In summary, this technical solution, through scientific component compounding, specific modification treatment, and reasonable process design, forms a synergistic and complementary overall system. It not only solves many technical defects of existing technologies, but also achieves a comprehensive improvement in the overall performance of pipe materials. Compared with existing technologies, it represents a significant and substantial advancement, better meeting the complex usage requirements of buried cable protection, and possesses extremely high practical value and industrial application prospects.

[0047] To further illustrate the beneficial technical effects of the various embodiments of the present invention, relevant performance tests were conducted on Embodiments 1-4 and Comparative Examples 1-6; The testing method is as follows: 1. Ring stiffness test: Select the prepared MPP cable protection pipe, cut it into samples of the specified length, place the sample horizontally on the testing device, use a two-point support method, slowly apply a uniform load until the sample shows obvious deformation, record the load value at this time, and calculate the ring stiffness data.

[0048] 2. Low-temperature impact strength test: Cut the pipe sample into standard specimens, place them in a low-temperature environment chamber, and keep them at a constant temperature of -20℃ for a sufficient time to ensure that the specimen temperature is consistent with the ambient temperature. Then, use an impact testing machine to perform an impact test on the specimen, record the impact energy required for the specimen to break, and calculate the low-temperature impact strength.

[0049] 3. Anti-aging performance test: Select standard pipe samples, put them into the ultraviolet aging test chamber, set a constant ultraviolet irradiation intensity, and irradiate continuously for 1000 hours. After the irradiation is completed, take out the samples and test their tensile strength. Compare the tensile strength with that of the unaged samples to obtain the tensile strength retention rate, and use this to evaluate the anti-aging performance.

[0050] 4. Wear resistance test: Fix the pipe sample on the wear test device, set a fixed friction speed and friction load, and use a standard friction medium to continuously rub against the sample surface. After rubbing for a specified time, weigh the sample before and after friction, and calculate the mass difference, which is the wear amount.

[0051] 5. Dimensional stability test: Cut a standard pipe sample, measure its initial size, put the sample into a high and low temperature cycling test chamber, set the cycling temperature from -20℃ to 60℃, keep the temperature constant for a specified time in each temperature range, and after completing several cycles, take out the sample, cool it to room temperature, measure its size again, and calculate the dimensional change rate.

[0052] 6. Tensile strength test: Cut the pipe sample into standard tensile specimens, and use a tensile testing machine to perform a tensile test on the specimens. Set a constant tensile speed until the specimen breaks, record the maximum tensile force at the time of breakage, and calculate the tensile strength based on the cross-sectional area of ​​the specimen.

[0053] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A MPP cable protection pipe material, characterized in that, Made from the following parts by weight of raw materials: Random copolymer polypropylene 80-90 parts, poly-1-butene 3-6 parts, organic modified montmorillonite 4-8 parts, maleic anhydride grafted ethylene propylene diene monomer (EPDM-g-MAH) 4-7 parts, epoxidized soybean oil 1-2.5 parts, antioxidant 1010 0.2-0.4 parts, antioxidant 168 0.15-0.3 parts, hindered amine light stabilizer 944 0.2-0.5 parts, polyethylene wax 0.4-0.8 parts, powder composite filler 3-6 parts, composite modifier 2-5 parts.

2. The MPP cable protection pipe according to claim 1, characterized in that, The random copolymer polypropylene has a melt index of 0.8-2.5 g / 10 min at 230℃ and 2.16 kg.

3. The MPP cable protection pipe according to claim 1, characterized in that, The organically modified montmorillonite is octadecyltrimethylammonium chloride-modified sodium montmorillonite with a lamellar spacing ≥2.5 nm.

4. The MPP cable protection pipe according to claim 1, characterized in that, The grafting rate of the maleic anhydride-grafted EPDM rubber is 0.6%-1.2%.

5. The MPP cable protection conduit according to claim 1, characterized in that, The organically modified montmorillonite is sodium montmorillonite modified with octadecyltrimethylammonium chloride, which is prepared by modifying sodium montmorillonite and octadecyltrimethylammonium chloride at a mass ratio of 100:3-5. The sodium montmorillonite needs to be dried at 105-115℃ for 2-3 hours to remove surface free water, and the mass fraction of the octadecyltrimethylammonium chloride aqueous solution is 1.5%-2.5%. The modification method of the organic modified montmorillonite is as follows: Sodium montmorillonite is dried in an oven at 105-115℃ for 2-3 hours to remove surface free water and cooled to room temperature. Then, it is added to an aqueous solution of 1.5%-2.5% by mass of octadecyltrimethylammonium chloride, wherein the mass ratio of sodium montmorillonite to octadecyltrimethylammonium chloride is 100:3-5. After stirring evenly, it is placed in a water bath at 60-70℃ and stirred at 300-400 r / min for 2-3 hours. After the reaction is completed, it is filtered and the filter cake is washed with deionized water until the conductivity of the washing liquid is ≤50μ / cm. The filter cake is then dried in an oven at 80-90℃ to constant weight, ground, and passed through a 200-mesh sieve to obtain the final product.

6. The MPP cable protection conduit according to claim 1, characterized in that, The powder composite filler is a multi-component composite material, which is composed of fly ash, carbon black and polyethylene glycol in a mass ratio of 4:2:1, wherein the fly ash is 800-1000 mesh and the carbon black is N330 type. The preparation method of the powder composite filler is as follows: Weigh fly ash, carbon black and polyethylene glycol according to the above mass ratio, put them into a high-speed mixer, mix for 12-18 minutes at 90-110℃ and 800-1000r / min, and then cool to room temperature to obtain the filler.

7. The MPP cable protection conduit according to claim 1, characterized in that, The composite modifier is a multi-component composite material, which is composed of maleic anhydride grafted POE, polylactic acid and nano silica in a mass ratio of 3:2:1, and the nano silica has a particle size of 20-50nm. The preparation method of the composite modifier is as follows: weigh each component according to the above mass ratio, put them into a twin-screw mixer, melt-blend for 8-12 minutes at 160-180℃ and 300-380r / min, extrude and granulate, cool to room temperature, and pulverize to 80-100 mesh to obtain the final product.

8. A method for preparing an MPP cable protection conduit as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Weigh each raw material according to the weight parts, first put the organic modified montmorillonite and epoxidized soybean oil into a high-speed mixer, mix at 60-80℃ for 5-8 minutes to complete the pretreatment of filler activation; S2: Take the powdered composite filler and composite modifier separately and put them into a high-speed mixer together. Mix them with the pretreated material from step S1 for 3-5 minutes to obtain a composite modified mixture. The powdered composite filler is composed of fly ash, carbon black and polyethylene glycol in a mass ratio of 4:2:

1. The preparation method is as follows: weigh fly ash, carbon black and polyethylene glycol in a mass ratio of 4:2:1, put them into a high-speed mixer, mix them at 90-110℃ and 800-1000 r / min for 12-18 minutes, and cool them to room temperature. The composite modifier is composed of maleic anhydride grafted POE, polylactic acid and nano silica in a mass ratio of 3:2:

1. The preparation method is as follows: weigh each component in a mass ratio of 3:2:1, put them into a twin-screw mixer, melt-blend them at 160-180℃ and 300-380 r / min for 8-12 minutes, extrude and granulate them, cool them to room temperature, and pulverize them to 80-100 mesh. S3: Add random copolymer polypropylene, poly-1-butene, maleic anhydride-grafted EPDM rubber, antioxidant 1010, antioxidant 168, light stabilizer 944, and polyethylene wax to the mixer, and continue mixing at room temperature for 8-10 minutes to obtain a uniform mixture. S4: Add the mixture to a twin-screw extruder, melt extrude and granulate to obtain MPP-specific modified material; S5: The modified material is extruded and shaped using a single screw extruder, vacuum sizing, cooling, traction, and length-cut to obtain the MPP cable protection pipe.

9. The preparation method according to claim 8, characterized in that, In step S4, the temperatures of each section of the twin-screw extruder are: 175-185℃, 185-195℃, 195-205℃, and 200-210℃, and the screw speed is 280-360 r / min.

10. The preparation method according to claim 8, characterized in that, In step S5, the temperature of the single-screw extruder is 195-215℃, the vacuum sizing pressure is 0.025-0.04MPa, and the cooling water temperature is 20-28℃.

Images