High-wear-resistance modified polyolefin pipe and preparation method thereof

Abstract

The invention belongs to the technical field of polyolefin pipes, and particularly provides a high-wear-resistance modified polyolefin pipe and a preparation method thereof.The high-wear-resistance modified polyolefin pipe is characterized in that the high-wear-resistance modified polyolefin pipe sequentially comprises a wear-resistant layer, an inner pipe, a steel wire mesh and an outer coating layer from inside to outside; the wear-resistant layer is prepared from the following raw materials in parts by mass: 85-90 parts of ultra-high molecular weight polyethylene, 3-5 parts of a modified toughening agent, 1-2 parts of conductive carbon black, 2-3 parts of an antioxidant and 0.5-2 parts of polyethylene wax; the modified toughening agent is prepared by the following steps: co-dispersing an iron-loaded core and swelling gelatin to obtain a precursor liquid, then precipitating and hardening the precursor liquid through a treatment liquid, and then baking, crushing and sieving the precursor liquid. The elongation at break of a polyolefin pipe wear-resistant layer product prepared from the modified flexibilizer is greater than or equal to 1005.6%, and the impact strength can reach 30.46 KJ / m < 2 >.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polyolefin pipes, and particularly relates to a high-wear-resistance modified polyolefin pipe and a preparation method thereof. BACKGROUND

[0002] The polyolefin pipe is a plastic pipe formed through extrusion, injection molding and other processes by taking polyethylene (PE), polypropylene (PP) and other polyolefin resins as main raw materials, and has excellent properties such as corrosion resistance, light weight and convenient installation, and has a high application prospect in the fields of municipal water supply and drainage, gas transportation, agricultural irrigation and industrial fluid transportation.

[0003] To expand the application of the polyolefin pipe in high-wear conditions such as coal mines, and particularly in the conveying scene of solid particles (such as coal powder and slag), it is a technical key to improve the wear resistance of the pipe. At present, the mainstream solution is to co-extrude a wear-resistant layer taking ultra-high molecular weight polyethylene (UHMWPE) as a base material on the innermost layer of the polyolefin pipe. Since UHMWPE has extremely high wear resistance, impact resistance and self-lubricating property, its wear life is more than 7 times that of ordinary carbon steel, which can significantly enhance the ability of the pipeline to resist the erosion and wear of solid particles.

[0004] However, UHMWPE also has certain technical problems. On the one hand, UHMWPE has extremely high wear resistance, but on the other hand, the elongation at break of UHMWPE is relatively low, resulting in insufficient flexibility and deformation capacity of the material. When the material flux in the conveying system is too high or the pressure fluctuation is large, the pipeline will periodically expand and recover. Under this dynamic deformation, the UHMWPE wear-resistant layer is difficult to stretch and contract synchronously with the outer layer of the polyolefin matrix with good toughness, and thus micro-cracks along the axial direction of the pipeline are easily generated due to stress concentration. These cracks will rapidly expand in the further use process, not only damaging the integrity of the wear-resistant layer, but also providing a channel for corrosive media, ultimately leading to premature failure of the pipe and greatly shortening its service life. Therefore, it is necessary to find a high-wear-resistance modified polyolefin pipe which can enhance the wear resistance of the wear-resistant layer while optimizing the toughness of UHMWPE material. SUMMARY

[0005] In view of the above problems, in order to further improve the wear resistance of the wear-resistant layer while taking into account the toughening effect, the application provides a high-wear-resistance modified polyolefin pipe and a preparation method thereof.

[0006] The application first provides a high-wear-resistance modified polyolefin pipe and a preparation method thereof, which comprises, from inside to outside, a wear-resistant layer, an inner pipe, a steel wire mesh and an outer coating layer. The wear-resistant layer is prepared from raw materials including the following components by mass: 85-90 parts of ultra-high molecular weight polyethylene, 3-5 parts of modified toughening agent, 1-2 parts of conductive carbon black, 2-3 parts of antioxidant, and 0.5-2 parts of polyethylene wax; the preparation steps include the following: The ultra-high molecular weight polyethylene, modified toughening agent, conductive carbon black, polyethylene wax, and antioxidant are mixed, and then are subjected to double-layer composite co-extrusion with hot melt adhesive to obtain the wear-resistant layer after cooling; The modified toughening agent is obtained by co-dispersing iron carrier core and swollen gelatin to obtain a precursor liquid, then precipitating and hardening in a treatment liquid, and then drying, crushing, and sieving; The steel wire mesh is obtained by wrapping hot melt adhesive on bare steel wires after degreasing and rust removal, and then weaving the wires into a mesh on an inner tube, and connecting the inner tube and the outer covering layer by electric heating melting.

[0007] By using the above technical solution, the modified toughening agent is a reinforced particle treated by a treatment liquid, the dispersed iron carrier core can serve as a central support structure to improve the strength of the toughening agent particles, and avoid the toughening effect of the toughening agent particles being lost due to excessive fragmentation during mechanical processing; the iron ions loaded on the iron carrier core can form a coordination structure with the amide bonds and amine groups on the polypeptide segments of the gelatin, thereby enhancing the entanglement between the gelatin molecular segments, and inhibiting the depolymerization behavior of the gelatin molecular polypeptide segments and the entangled chains of peptide bonds during the high-temperature treatment of the pipe wear-resistant layer extrusion; the hardness of the precursor liquid is further improved after the treatment liquid precipitates and hardens, and then the modified toughening agent dispersed on the surface of the wear-resistant layer after subsequent melt blending with the wear-resistant layer raw materials can act as a wear-resistant particle to improve the wear resistance of the wear-resistant layer; when external force acts on the wear-resistant layer, the micro-nano modified toughening agent is affected by the hardness difference and phase separation of the wear-resistant layer system, and is adhered and detached to form a dissipative structure in the wear-resistant layer matrix, thereby consuming energy and inhibiting the growth of pipe wall cracks, and achieving the toughening effect of the wear-resistant layer.

[0008] Further, the preparation steps of the modified toughening agent include the following: S01. Take water, adjust the pH to 4.3-5.0, then add ferrous sulfate, dissolve, then add carrier particles, heat and stir, then filter and calcine to obtain the iron carrier core; the calcination uses a mixed gas with an oxygen content of 2% by volume and an argon content of 98% by volume; the calcination is performed at a temperature of 350-500℃ for 2-4h; S02. Take the type A gelatin, swell treatment, then add 3-4 times the volume of water, constant temperature stirring at 50-60 DEG C, then add the iron carrier, continue to stir, to obtain the precursor liquid; the mass ratio of the type A gelatin and the iron carrier used is 5:(0.2-0.3); further, in the step S02, the treatment liquid contains tannic acid with a mass concentration of 5.2%-6.5%; the dropwise adding speed is 1.2-1.7 mL / min; S03. Take the precursor liquid, dropwise add the treatment liquid, stir, then sequentially perform suction filtration, water washing, drying, then crush and sieve through a 325 mesh sieve to obtain the product; the drying treatment is set at an oven temperature of 90-105 DEG C, and air drying is performed overnight.

[0009] By adopting the above technical scheme, under hydrothermal conditions, ferrous sulfate is adsorbed on the carrier microparticles, and is fixed on the carrier microparticles in the form of high-valence iron oxide in a calcination oxidation atmosphere, and then a high-activity iron carrier is obtained; when the iron carrier is subsequently blended with swollen type A gelatin, it is dispersed in the swollen gelatin molecular system, and forms a preliminary entanglement structure with the gelatin polypeptide chain through coordination, and then the gelatin polypeptide chain segment conformation is further treated by the treatment liquid, and is contracted and hardened, and finally a modified toughening agent with toughening and strong hard properties can be obtained after baking and crushing treatment.

[0010] Further, in the step S01, the carrier microparticles are one of silica ash and alumina.

[0011] Further, the hot melt adhesive contains 3%-5% of terpene resin.

[0012] Further, the composite co-extrusion is set at an extrusion temperature of 180-215 DEG C, a processing rotation speed of 100-120 rpm, and a shaping temperature of 150-175 DEG C.

[0013] Further, the steel wire mesh weaving adopts double-layer crossing, 250-260 wires, and is wound at an angle of 45-55 DEG to the outer surface of the inner tube.

[0014] The application also provides a high-wear-resistance modified polyolefin pipe prepared by the above preparation method.

[0015] Compared with the prior art, the application has the following beneficial effects: 1. The application adds a modified toughening agent to the wear-resistant layer of the polyolefin pipe, the toughening agent has an iron carrier as a central structure and is treated by a plant-derived tannic acid, so that the hardness of the toughening agent particles can be enhanced; the iron ions loaded on the iron carrier can entangle with the gelatin polypeptide molecular chain through coordination, thereby improving the thermal stability of the toughening agent; after the modified toughening agent is dispersed on the surface of the wear-resistant layer, the wear resistance of the wear-resistant layer can be improved.

[0016] 2、The modified toughening agent of the application can also play a toughening effect on the wear-resistant layer pipe, when external force acts on the wear-resistant layer and conducts to the inner layer, the modified toughening agent of micro-nano sticks and detaches to form a dissipative structure in the matrix to consume energy, which can inhibit the cracking behavior of the wear-resistant layer and improve the toughness of the wear-resistant layer.

[0017] 3、The polyolefin pipe wear-resistant layer product prepared by using the modified toughening agent of the application has an elongation at break of ≥1005.6% and an impact strength of up to 30.46 KJ / m 2 . BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the high-wear-resistant modified polyolefin pipe of the application.

[0019] Figure 2 The figure is the SEM scanning test result of the wear-resistant layer sample section after impact strength test of Example 1 and Comparative Example 2 of the application.

[0020] The figure is a schematic diagram of the high-wear-resistant modified polyolefin pipe of the application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and beneficial technical effects of the application of the application clearer, the application will be further described in detail below in combination with examples. Obviously, the described examples are only some of the examples of the application, but not all the examples. Based on the examples in the application, all other examples obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0023] In the case of using "including", "having", and "containing" described herein, it is intended to cover non-exclusive inclusion, unless the explicit limiting term such as "only", "consisting of", etc. is used, otherwise another component can also be added.

[0024] The terms "preferred," "more preferably," "better," and "even better" used in this application refer to embodiments of this application that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application. That is, in this application, "preferred," "more preferably," "better," and "even better" are merely descriptions of implementations or embodiments with better effects, but do not constitute a limitation on the scope of protection of this application.

[0025] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0026] In this application, "at least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two layers, three layers, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0027] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0028] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method comprising steps (a) and (b) indicates that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0029] In this application, "above" or "below" includes the number itself. For example, "below 1" includes 1.

[0030] In the present application, room temperature refers to 0-40℃, including but not limited to 10-40℃, or further 20-30℃.

[0031] The present application is further illustrated by the following examples, but not limited to the scope of the present application.

[0032] When the examples give a numerical range, it should be understood that, unless otherwise specified in the present application, both ends of each numerical range and any one numerical between the two ends can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art. If the specific conditions are not indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the manufacturer of all reagents or instruments is not indicated, it is a conventional product that can be purchased on the market. In addition to the specific methods, equipment, materials used in the examples, according to the mastery of the prior art by those skilled in the art and the description of the present application, any method, equipment and material of the prior art similar or equivalent to the method, equipment and material described in the examples of the present application can also be used to realize the present application.

[0033] The structure of the high wear-resistant modified polyolefin pipe material of examples 1-3 and comparative examples 1-2 is shown in Figure 1 .

[0034] Preparation example 1 Take 80 mL of deionized water, adjust the pH to 4.3, then add 1.25 g of ferrous sulfate, stir for 2 min, then add 11.4 g of aluminum oxide (2 microns), adjust the temperature to 60℃, low speed stirring at 50 rpm, stirring for 1 h, then filter the solid part, dry in the oven at 45℃, then transfer to the muffle furnace, 2% O2 / 98% Ar gas atmosphere, 350℃ calcination for 2 h to obtain the iron-loaded core; Take 5 g of type A gelatin, swell in 30 mL of deionized water, then add 3 times the volume of deionized water, constant temperature stirring at 50℃ for 15 min, then add 0.2 g of iron-loaded core, continue to stir to obtain the precursor liquid.

[0035] Take 5.2 g of tannic acid, then add 10 mL of 8% mass concentration of ice acetic acid buffer, make up to 100 mL to obtain the treatment liquid.

[0036] Take 50 mL of the precursor liquid, adjust the temperature to 40℃, add the treatment liquid at a speed of 1.2 mL / min, continue to stir for 1 h, then filter the filter cake, wash with water for 2 times, set the oven temperature to 90℃, air dry overnight, then use a high-speed pulverizer to crush and pass through a 325 mesh sieve to obtain the modified toughening agent.

[0037] Preparation example 2 Take 90 mL of deionized water, adjust the pH to 4.7, then add 1.5 g of ferrous sulfate, stir for 2 min, then add 11.8 g of silica fume (2 microns), adjust the temperature to 65℃, and stir at a low speed of 75 rpm for 1 h. Then filter to collect the solid part, dry it in an oven at 45℃, and transfer it to a muffle furnace. Calcine it at 455℃ for 2.5 h under a 2% O2 / 98% Ar gas atmosphere to obtain the iron-supported core. Take 5g of type A gelatin, add 35mL of deionized water to fully swell, then add 3 times the volume of deionized water, stir at 55℃ for 15min, then add 0.25g of iron-loaded core, continue stirring to obtain the precursor fluid.

[0038] Take 5.8g of tannic acid, then add 10mL of 8% glacial acetic acid buffer, and bring the volume up to 100mL to obtain the treatment solution.

[0039] Take 50 mL of precursor fluid, adjust the temperature to 50℃, add 175 mL of treatment solution dropwise at a rate of 1.7 mL / min, stir continuously for 2 h, then filter to obtain filter cake, wash twice with water, set the oven temperature to 105℃, dry overnight with forced air, then use a high-speed pulverizer to pulverize and pass through a 325 mesh sieve to obtain modified toughening agent.

[0040] Preparation Example 3 Take 100 mL of deionized water, adjust the pH to 5.0, then add 1.7 g of ferrous sulfate, stir for 3 min, then add 12 g of silica fume (3 microns), adjust the temperature to 80 ℃, stir at a magnetic stirring speed of 100 rpm for 2 h, then filter to take the solid part, dry in an oven at 45 ℃, then transfer to a muffle furnace, and calcine at 500 ℃ for 4 h under a 2% O2 / 98% Ar gas atmosphere to obtain the iron-supported core; Take 5g of type A gelatin, add 50mL of deionized water to fully swell, then add 4 times the volume of deionized water, stir at 60℃ for 20min, then add 0.3g of iron-loaded core, continue stirring to obtain the precursor fluid.

[0041] Take 6.5g of tannic acid, then add 10mL of 8% glacial acetic acid buffer, and bring the volume up to 100mL to obtain the treatment solution.

[0042] Take 50 mL of precursor fluid, adjust the temperature to 50℃, add 200 mL of treatment solution dropwise at a rate of 1.7 mL / min, stir continuously for 2 h, then filter to obtain filter cake, wash with water 3 times, set the oven temperature to 105℃, dry overnight with forced air, then use a high-speed pulverizer to pulverize and pass through a 325 mesh sieve to obtain modified toughening agent.

[0043] Example 1 Take 1.7 kg of ultra-high molecular weight polyethylene (model: GUR-4170), 60 g of modified toughening agent, 20 g of conductive carbon black, 10 g of polyethylene wax, and 40 g of antioxidant-1010. Mix them in a high-speed mixer for 10 min. Then, co-extrude them with hot melt adhesive (containing 3% terpene resin). Set the extrusion temperature to 180℃, the processing speed to 100 rpm, and the setting temperature to 150℃ to obtain the wear-resistant layer (1). After cooling, obtain the wear-resistant tube preform. Then, co-extrude it with the inner tube polypropylene (MI < 2.2 g / 10 min) raw material to obtain the inner tube (2) formed on the surface of the wear-resistant tube preform. Temperature control After heat treatment at 50℃ for 30 minutes, the wire was placed to cool for 1 hour. Then, the bare steel wire was degreased, derusted, dried, and coated with hot melt adhesive using a glue machine. The pretreated steel wire was woven into the outer surface of the inner tube using a double-layer cross-bracing method with 250 wires at a 45° angle to obtain a steel wire mesh (3). Subsequently, the wire was heat-treated at 50℃ for 1 hour in a temperature-controlled chamber and then cooled and cured to obtain a steel wire reinforced core tube. Then, according to the diameter of the steel wire reinforced core tube, the outer coating layer polyethylene (MI < 1.5 g / 10 min) raw material was placed in a pipe extruder to co-extrude the outer coating layer (4). After electrothermal melting treatment, the tube was cooled, pulled, and cut to obtain a high wear-resistant modified polyolefin pipe.

[0044] In this embodiment, the modified toughening agent was prepared in Preparation Example 1.

[0045] Example 2 Take 1.75 kg of ultra-high molecular weight polyethylene (model: GUR-4170), 80 g of modified toughening agent, 35 g of conductive carbon black, 15 g of polyethylene wax, and 50 g of antioxidant-1010 and mix them in a high-speed mixer for 12 min. Then, co-extrude the mixture with hot melt adhesive (containing 3.2% terpene resin) at an extrusion temperature of 190℃, a processing speed of 120 rpm, and a setting temperature of 165℃ to obtain a wear-resistant layer (1). After cooling, a wear-resistant tube preform is obtained. Then, it is co-extruded with inner tube polypropylene (MI < 2.2 g / 10 min) raw material to obtain an inner tube (2) with the surface of the wear-resistant tube preform. After heat treatment at 65℃ for 40 minutes in a temperature control chamber, the wire is placed to cool for 1 hour. Then, the bare steel wire is degreased, derusted, dried, and coated with hot melt adhesive using a glue machine. The pretreated steel wire is woven into the outer surface of the inner tube using a double-layer cross pattern with 255 wires at a 45° angle to obtain a steel wire mesh (3). Subsequently, the wire is heat-treated at 60℃ for 2 hours in a temperature control chamber and then cooled and cured to obtain a steel wire reinforced core tube. Then, according to the diameter of the steel wire reinforced core tube, the outer coating layer polyethylene (MI < 1.5 g / 10 min) raw material is placed in a pipe extruder to co-extrude the outer coating layer (4). After electrothermal melting treatment, the tube is cooled, pulled, and cut to obtain a high wear-resistant modified polyolefin pipe.

[0046] In this embodiment, the modified toughening agent was prepared from Preparation Example 2.

[0047] Example 3 Take 1.8 kg of ultra-high molecular weight polyethylene (model: GUR-4170), 100 g of modified toughening agent, 40 g of conductive carbon black, 40 g of polyethylene wax, and 60 g of antioxidant-1010. Mix them in a high-speed mixer for 15 min, then co-extrude them with hot melt adhesive (containing 5% terpene resin). Set the extrusion temperature to 215℃, the processing speed to 120 rpm, and the setting temperature to 175℃ to obtain a wear-resistant layer (1). After cooling, obtain a wear-resistant tube preform. Then co-extrude it with inner tube polypropylene (MI < 2.2 g / 10 min) raw material to obtain an inner tube (2) with the surface of the wear-resistant tube preform. After heat treatment at 70℃ for 50 minutes, the wire was placed to cool for 1 hour. Then, the bare steel wire was degreased, derusted, dried, and coated with hot melt adhesive using a glue machine. The pretreated steel wire was woven into the outer surface of the inner tube using a double-layer cross-bracing method with 260 wires at a 55° angle to obtain a steel wire mesh (3). Subsequently, the wire was heat-treated at 60℃ for 2 hours in a temperature-controlled chamber and then cooled and cured to obtain a steel wire reinforced core tube. Then, according to the diameter of the steel wire reinforced core tube, the outer coating layer polyethylene (MI < 1.5 g / 10 min) raw material was placed in a pipe extruder to co-extrude the outer coating layer (4). After electrothermal melting treatment, the tube was cooled, pulled, and cut to obtain a high wear-resistant modified polyolefin pipe.

[0048] In this embodiment, the modified toughening agent was prepared from Preparation Example 3.

[0049] Comparative Example 1 The difference between this comparative example and Example 1 is that the preparation steps of the precursor fluid are as follows: Take 5g of type A gelatin, add 30mL of deionized water to fully swell, then add 3 times the volume of deionized water, stir at 50℃ for 15min, and continue stirring to obtain the precursor fluid.

[0050] The remaining steps are the same as in Example 1.

[0051] Comparative Example 2 The difference between this comparative example and Example 1 is that polyaluminum chloride (5 mg / L) was used instead of the treatment solution.

[0052] The remaining steps are the same as in Example 1.

[0053] Performance testing 1. Apparent performance test The test items and test indicators of the wear-resistant layer appearance performance of Examples 1-3 and Comparative Examples 1-2 are shown in Table 1.

[0054] Table 1. Test items and test indicators for the apparent performance of wear-resistant layers in Examples 1-3 and Comparative Examples 1-2 The test results are shown in Table 2.

[0055] Table 2. Test results of the apparent properties of the wear-resistant layers in Examples 1-3 and Comparative Examples 1-2 Comparing Examples 1-3 and Comparative Examples 1-2 with Tables 1 and 2, it can be concluded that the wear-resistant layer prepared using the methods in the examples exhibits significantly improved tensile strength, impact strength, and elongation at break compared to the comparative examples, demonstrating "strong and tough" characteristics, which better meet the performance requirements of wear-resistant pipes. Comparative Examples 1 and 2 respectively set up comparative schemes for treating the precursor fluid using denuclearization and physical precipitation methods. The modified toughening agent showed poor hardening and thermal stability, and the modified toughening agent, after being added to the system, posed a risk of thermal melting decomposition and excessive breakage, affecting the strength of the wear-resistant layer product. Combined with the wear rate data, under the same test environment, the modified toughening agent particles in the comparative examples were more easily lost due to erosion, which would exacerbate the wear of the wear-resistant pipe and shorten its expected service life.

[0056] 2. SEM testing After impact strength testing, the test samples from Example 1 and Comparative Example 2 were subjected to cross-sectional SEM scanning tests. The test results are as follows: Figure 2 As shown.

[0057] From Example 1 and Comparative Example 2, and in conjunction with Table 2 and Figure 2 It can be concluded that after the impact test, the test sample of Example 1 showed a large number of micron-sized cavitation bubbles in its cross-section, which is a manifestation of the toughening agent sticking off. When the wear-resistant layer system is subjected to external impact, the modified toughening agent particles dispersed in the wear-resistant layer polyolefin matrix slip along the direction of force. However, due to the difference in hardness and compatibility between the modified toughening agent particles and the matrix system, the degree of recovery deformation after slippage is different, thus forming a dissipative structure centered on the modified toughening agent, which increases the energy consumption of the system and inhibits the impact fracture behavior of the material. In contrast, the modified toughening agent of Comparative Example 2 is affected by the degree of hardening. When subjected to external impact, the deformation behavior of the toughening agent particles and the matrix is ​​more consistent, and the occurrence of cavitation bubbles generated by recovery deformation is significantly reduced. Combined with the impact strength test data in Table 2, the impact strength of Example 1 is significantly higher than that of Comparative Example 2, which further illustrates the effect of the modified toughening agent in the examples on inhibiting the brittle fracture of the wear-resistant layer.

[0058] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a highly wear-resistant modified polyolefin pipe, characterized in that, From the inside out, it includes a wear-resistant layer, an inner tube, a wire mesh, and an outer covering layer; The wear-resistant layer is prepared from raw materials comprising the following parts by weight: 85-90 parts ultra-high molecular weight polyethylene, 3-5 parts modified toughening agent, 1-2 parts conductive carbon black, 2-3 parts antioxidant, and 0.5-2 parts polyethylene wax; the preparation steps include the following: Take ultra-high molecular weight polyethylene, modified toughening agent, conductive carbon black, polyethylene wax and antioxidant, mix them, and then co-extrude them with hot melt adhesive in two layers. After cooling, a wear-resistant layer is obtained. The modified toughening agent is obtained by co-dispersing iron core and swollen gelatin to obtain a precursor liquid, which is then hardened by precipitation in a treatment liquid, and then dried, pulverized and sieved. The wire mesh is made by degreasing and removing rust from bare steel wire, coating it with hot melt adhesive, and then weaving it into a mesh on the inner tube. The inner tube and the outer covering layer are connected by electrofusion.

2. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 1, characterized in that, The preparation steps of the modified toughening agent include the following: S01. Take water, adjust the pH to 4.3-5.0, then add ferrous sulfate to dissolve it, then add carrier microparticles, heat and stir, then filter and calcine to obtain the iron-supported core; the carrier microparticles are one of silica fume and alumina; S02. Take type A gelatin, add water to swell it, then add 3-4 times the volume of water, stir at a constant temperature of 50-60℃, then add iron core, continue stirring to obtain precursor fluid; S03. Take the precursor fluid, add the treatment solution, stir and treat, then filter, wash with water, dry, and then crush and sieve through a 325-mesh sieve to obtain the product.

3. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 2, characterized in that, In step S01, the calcination atmosphere is a mixture of 2% oxygen and 98% argon by volume; the calcination is carried out at a temperature of 350-500℃ for 2-4 hours.

4. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 2, characterized in that, In step S02, the mass ratio of type A gelatin to iron core used is 5:(0.2-0.3).

5. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 2, characterized in that, In step S03, the treatment solution contains tannic acid with a mass concentration of 5.2%-6.5%; the dropping rate is 1.2-1.7 mL / min.

6. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 2, characterized in that, In step S03, the drying process involves setting the oven temperature to 90-105℃ and drying overnight with forced air.

7. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 1, characterized in that, The hot melt adhesive contains 3%-5% terpene resin.

8. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 1, characterized in that, The composite co-extrusion is set with an extrusion temperature of 180-215℃, a processing speed of 100-120rpm, and a setting temperature of 150-175℃.

9. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 1, characterized in that, The wire mesh is woven in a double-layer cross pattern, with 250-260 strands wound at a 45-55° angle onto the outer surface of the inner tube.

10. A high-wear-resistant modified polyolefin pipe, characterized in that, It is prepared by any one of the preparation methods described in claims 1-9.

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