Highly abrasion resistant modified polyolefin pipe and method of making same

Abstract

The application belongs to the technical field of polyolefin pipes, and specifically provides a high-wear-resistance modified polyolefin pipe and a preparation method thereof, characterized by sequentially comprising a wear-resistant layer, an inner pipe, a steel wire mesh and an outer cladding layer from inside to outside; the wear-resistant layer is prepared from raw materials including the following components 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 obtained by co-dispersing iron carrier cores and swollen gelatin to obtain a precursor liquid, then precipitating and hardening in a treatment liquid, and then being dried, crushed and sieved; the polyolefin pipe wear-resistant layer product prepared from the modified toughening agent has an elongation at break of ≥1005.6% and an impact strength of up to 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 the like by taking polyethylene (PE), polypropylene (PP) and the like as main raw materials. Due to excellent properties such as corrosion resistance, light weight and convenient installation, the polyolefin pipe 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 key technology 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 pipe 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 pipe 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 pipe 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, eventually leading to premature failure of the pipe and greatly shortening the service life of the pipe. Therefore, it is necessary to find a high-wear-resistance modified polyolefin pipe which can enhance the wear resistance of the wear-resistant layer and optimize 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 and simultaneously consider 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. From inside to outside, the pipe comprises a wear-resistant layer,

[0007] an inner pipe, a steel wire mesh and an outer coating layer.

[0008] The wear-resistant layer is prepared from raw materials including the following components in 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:

[0009] 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;

[0010] The modified toughening agent is obtained by dispersing iron carrier cores and swollen gelatin to obtain a precursor liquid, and then precipitating and hardening the precursor liquid with a treatment liquid, and then drying, crushing, and sieving.

[0011] The steel wire mesh is obtained by wrapping hot melt adhesive on bare steel wires after degreasing and rust removal, and weaving the steel wires into a mesh on an inner tube, and connecting the inner tube and the outer covering layer by electric heating melting.

[0012] By using the above technical solution, the modified toughening agent is a reinforced particle treated by a treatment liquid, the dispersed iron carrier cores can act as a central support structure to improve the strength of the toughening agent particles, and the toughening effect of the toughening agent particles is not lost due to excessive crushing during mechanical processing; the iron ions loaded on the iron carrier cores can form a coordination structure with the amide bonds and amine groups on the polypeptide segments of the gelatin molecules in the precursor liquid, 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 the subsequent drying treatment, and after the subsequent melt blending with the wear-resistant layer raw materials, the modified toughening agent dispersed on the surface of the wear-resistant layer can act as a wear-resistant particle to improve the wear-resistant properties of the wear-resistant layer, and 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 the modified toughening agent 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, thereby achieving the toughening effect of the wear-resistant layer.

[0013] Further, the preparation steps of the modified toughening agent include the following:

[0014] 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 iron carrier cores; the calcination uses a mixed gas with a volume fraction of 2% oxygen and a volume fraction of 98% argon as the gas atmosphere; the calcination is performed at a temperature of 350-500℃ for 2-4h;

[0015] S02. Take the A type gelatin, swell treatment, then add 3-4 times 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 A type 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;

[0016] S03. Take the precursor liquid, dropwise add the treatment liquid, stir treatment, 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 to an oven temperature of 90-105 DEG C, and air drying is performed overnight.

[0017] 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 the swollen A type 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 the modified toughening agent with toughening and strong hard properties can be obtained after baking and crushing treatment.

[0018] Further, in the step S01, the carrier microparticles are one of silica ash and alumina.

[0019] Further, the hot melt adhesive contains 3%-5% of terpene resin.

[0020] Further, the composite co-extrusion is set to 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.

[0021] Further, the steel wire mesh weaving adopts double-layer crossing, 250-260 wires, and is wound to the outer surface of the inner tube at an angle of 45-55 DEG.

[0022] The application also provides a high-wear-resistance modified polyolefin pipe prepared by the above method.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] 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, so that the thermal stability of the toughening agent is improved; 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.

[0025] 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.

[0026] 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

[0027] Figure 1 It is a structural schematic diagram of the high-wear-resistant modified polyolefin pipe of the application.

[0028] Figure 2 It 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.

[0029] The reference signs are explained as follows: 1, wear-resistant layer; 2, inner pipe; 3, steel wire mesh; 4, outer cladding layer. DETAILED DESCRIPTION

[0030] In order to make the purposes, technical solutions and beneficial technical effects of the application clearer, the application is 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 the other examples obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0031] 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.

[0032] In the case of using "comprising", "having", and "including" described herein, it is intended to cover non-exclusive inclusion, unless an explicit limiting term is used, such as "only", "consisting of", and the like, another component can also be added.

[0033] The words "preferably," "more preferably," "most preferably," and the like, in the specification, mean that in certain situations, one embodiment can provide certain benefits, however, other embodiments can also be preferred for the same reasons or for other reasons. Also, the use of these terms does not foreclose from the scope of the application other embodiments that can not include certain of the benefits and features.

[0034] In the specification, the use of the term "further," "more," "additional" and the like, means that the content is additional to that which is already described, but should not be interpreted as limiting the scope of the application.

[0035] In the specification, the meaning of "at least one" is one or more, such as one, two, and more than two. The meaning of "a plurality" or "several" is at least two, such as two, three, and the like. The meaning of "a plurality of" or "several of" is at least two, such as two, three, and the like, unless otherwise indicated by specific language. In the specification, the meaning of "a number of" is at least one, such as one, two, and the like, unless otherwise indicated by specific language.

[0036] When a range of values is disclosed, unless otherwise stated the range is a continuous range including the minimum and maximum values, and each intervening value by itself, including the minimum and maximum values. Further, when a range of values is provided, it is understood that each intervening value, to the exclusion of any other values outside the specified range, between the minimum and the maximum value are also specifically included within the range. For example, if a range of 1 to 5 is stated, then 3.14 is also specifically stated as applicable. Other examples of included ranges are disclosed, unless otherwise indicated by specific language.

[0037] Unless specifically stated otherwise, all steps, processes, methods and / or algorisms described herein can be performed in sequential order, or in parallel, or in any suitable order, as appropriate, unless otherwise indicated. For example, if a method comprises steps (a) and (b), then the method can comprise performing steps (a) and (b) in that order, or performing steps (b) and (a) in that order. For example, if a method is described as comprising step (c), then the method can comprise performing steps (a), (b) and (c) in that order, or performing steps (a), (c) and (b) in that order, or performing steps (c), (a) and (b) in that order, etc. Unless otherwise indicated, singular forms of terms are meant to include the plural forms of the terms, and are not meant to be limited to quantities of one.

[0038] In the specification, "above" or "below" includes the number itself. For example, 1 or below includes 1.

[0039] In the present application, room temperature refers to 0-40℃, including but not limited to 10-40℃, or further 20-30℃.

[0040] The present application is further illustrated by the following examples, but not limited to the scope of the present application.

[0041] 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 number 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 no specific conditions are indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If no manufacturer of all reagents or instruments is 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, any method, equipment and material of the prior art similar or equivalent to the methods, equipment and materials described in the examples of the present application can also be used to realize the present application according to the mastery of the prior art by those skilled in the art and the description of the present application.

[0042] The structure diagram of high wear-resistant modified polyolefin pipe material of examples 1-3 and comparative examples 1-2 is shown as follows. Figure 1

[0043] Preparation example 1

[0044] 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 iron-loaded core;

[0045] 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.

[0046] Take 5.2 g of tannic acid, then add 10 mL of 8% mass concentration of ice acetic acid buffer, dilute to 100 mL to obtain the treatment liquid.

[0047] 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.

[0048] Preparation example 2 ​

[0049] 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 ash (2 microns), adjust the temperature to 65°C, low speed stirring at 75 rpm for 1 h, then filter the solid part, dry in the oven at 45°C, then transfer to the muffle furnace, 2% O2 / 98% Ar gas atmosphere, 455°C calcination for 2.5 h to obtain the iron carrier core;

[0050] Take 5 g of type A gelatin, add 35 mL of deionized water to swell, then add 3 times the volume of deionized water, constant temperature stirring at 55°C for 15 min, then add 0.25 g of iron carrier core, continue stirring to obtain the precursor liquid.

[0051] Take 5.8 tannic acid, then add 10 mL of 8% mass concentration of ice acetic acid buffer, dilute to 100 mL to obtain the treatment liquid.

[0052] Take 50 mL of the precursor liquid, adjust the temperature to 50°C, add the treatment liquid at a speed of 1.7 mL / min, continue stirring for 2 h, then filter the filter cake, wash with water 2 times, set the oven temperature to 105°C, air dry overnight, then use a high-speed pulverizer to crush and pass through a 325 mesh sieve to obtain the modified toughening agent.

[0053] Preparation Example 3

[0054] 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 ash (3 microns), adjust the temperature to 80°C, low speed stirring at 100 rpm for 2 h, then filter the solid part, dry in the oven at 45°C, then transfer to the muffle furnace, 2% O2 / 98% Ar gas atmosphere, 500°C calcination for 4 h to obtain the iron carrier core;

[0055] Take 5 g of type A gelatin, add 50 mL of deionized water to swell, then add 4 times the volume of deionized water, constant temperature stirring at 60°C for 20 min, then add 0.3 g of iron carrier core, continue stirring to obtain the precursor liquid.

[0056] Take 6.5 g of tannic acid, then add 10 mL of 8% mass concentration of ice acetic acid buffer, dilute to 100 mL to obtain the treatment liquid.

[0057] Take 50 mL of the precursor liquid, adjust the temperature to 50°C, add the treatment liquid at a speed of 1.7 mL / min, continue stirring for 2 h, then filter the filter cake, wash with water 3 times, set the oven temperature to 105°C, air dry overnight, then use a high-speed pulverizer to crush and pass through a 325 mesh sieve to obtain the modified toughening agent.

[0058] Example 1

[0059] 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, 40 g of antioxidant-1010 high-speed mixer for 10 min, then compound co-extrusion with hot melt adhesive (containing 3% terpene resin), set the extrusion temperature to 180℃, processing speed 100 rpm, setting temperature 150℃, get wear-resistant layer (1), after cooling to get wear-resistant pipe embryo material, then co-extrusion with inner tube polypropylene (MI <2.2 g / 10 min) raw material, get the inner tube (2) of wear-resistant pipe embryo surface forming, after 50℃ heat treatment for 30 min in the temperature control box, place cooling for 1 h, then take the bare steel wire degreasing, rust removal, drying, and then wrap the hot melt adhesive with the glue machine, adopt double-layer cross, 250 roots, 45° to the pre-processed steel wire woven to the outer surface of the inner tube, get the steel wire mesh (3), then heat treatment for 1 h in the temperature control room at 50℃ and then cooling and solidification to get the steel wire reinforced core pipe, then according to the pipe diameter of the steel wire reinforced core pipe, put the outer cladding layer polyethylene (MI <1.5 g / 10 min) raw material into the pipe extruder for co-extrusion to get the outer cladding layer (4), after electric hot melt treatment, cooling, traction and cutting to get the high wear-resistant modified polyolefin pipe.

[0060] In this embodiment, the modified toughening agent is prepared by Preparation Example 1.

[0061] Example 2

[0062] 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, 40 g of antioxidant-1010 high-speed mixer for 10 min, then compound co-extrusion with hot melt adhesive (containing 3% terpene resin), set the extrusion temperature to 180℃, processing speed 100 rpm, setting temperature 150℃, get wear-resistant layer (1), after cooling to get wear-resistant pipe embryo material, then co-extrusion with inner tube polypropylene (MI <2.2 g / 10 min) raw material, get the inner tube (2) of wear-resistant pipe embryo surface forming, after 50℃ heat treatment for 30 min in the temperature control box, place cooling for 1 h, then take the bare steel wire degreasing, rust removal, drying, and then wrap the hot melt adhesive with the glue machine, adopt double-layer cross, 250 roots, 45° to the pre-processed steel wire woven to the outer surface of the inner tube, get the steel wire mesh (3), then heat treatment for 1 h in the temperature control room at 50℃ and then cooling and solidification to get the steel wire reinforced core pipe, then according to the pipe diameter of the steel wire reinforced core pipe, put the outer cladding layer polyethylene (MI <1.5 g / 10 min) raw material into the pipe extruder for co-extrusion to get the outer cladding layer (4), after electric hot melt treatment, cooling, traction and cutting to get the high wear-resistant modified polyolefin pipe.

[0063] In this embodiment, the modified toughening agent is prepared by Preparation Example 2.

[0064] Example 3

[0065] 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, 60 g of antioxidant-1010 high-speed mixer for 15 min, then compound with hot melt adhesive (containing 5% terpene resin) co-extrusion, set the extrusion temperature to 215℃, processing speed 120 rpm, setting temperature 175℃, get wear-resistant layer (1), after cooling to get wear-resistant pipe embryo material, then co-extruded with inner tube polypropylene (MI <2.2 g / 10 min) raw material, get wear-resistant pipe embryo surface forming inner tube (2), after 70℃ heat treatment for 50 min in temperature control box, cool for 1 h, then take the bare steel wire degreasing, rust removal, drying, and then wrap the hot melt adhesive with the glue machine, adopt double-layer cross, 260 roots, 55° to the pre-treatment steel wire woven to the outer surface of the inner tube, get steel wire mesh (3), then heat treatment in temperature control room at 60℃ for 2 h and cooling to get steel wire reinforced core pipe, then according to the diameter of the steel wire reinforced core pipe, the outer coating layer polyethylene (MI <1.5 g / 10 min) raw material is placed in the pipe extruder for co-extrusion to get the outer coating layer (4), after electric hot melt treatment, cooling, traction and cutting to get high wear-resistant modified polyolefin pipe.

[0066] In this embodiment, the modified toughening agent is prepared by Preparation Example 3.

[0067] Comparative Example 1

[0068] The difference between this comparative example and Example 1 is that the preparation steps of the precursor solution are as follows:

[0069] Take 5 g of type A gelatin, swell in 30 mL of deionized water, then add 3 times the volume of deionized water, and stir at 50℃ for 15 min, continue to stir to get the precursor solution.

[0070] The remaining steps are the same as Example 1.

[0071] Comparative Example 2

[0072] The difference between this comparative example and Example 1 is that polyaluminum chloride (5 mg / L) is used instead of the treatment solution.

[0073] The remaining steps are the same as Example 1.

[0074] Performance test

[0075] 1. Appearance performance test

[0076] The appearance performance test items and test indexes of the wear-resistant layer of Examples 1-3 and Comparative Examples 1-2 are shown in Table 1.

[0077] Table 1 Appearance performance test items and test indexes of wear-resistant layer of Examples 1-3 and Comparative Examples 1-2

[0078]

[0079] The test results are shown in Table 2.

[0080] Table 2. Test results of the apparent properties of the wear-resistant layers in Examples 1-3 and Comparative Examples 1-2

[0081]

[0082] 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.

[0083] 2. SEM testing

[0084] 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.

[0085] 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.

[0086] Although the present application has been described in detail with reference to the foregoing embodiments, the technical solutions recorded in the foregoing embodiments can be modified by those skilled in the art, or some technical features thereof can be replaced by equivalents, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present 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. 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 either silica fume or alumina; 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. 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 the iron core, and continue stirring to obtain the precursor fluid; in step S02, the mass ratio of type A gelatin to iron core is 5:(0.2-0.3). 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; 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.

2. The method for preparing a high wear-resistant modified polyolefin pipe according to claim 1, characterized in that, In step S03, the drying process involves setting the oven temperature to 90-105℃ and drying overnight with forced air.

3. 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.

4. 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℃.

5. 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.

6. A highly wear-resistant modified polyolefin pipe, characterized in that, It is prepared by any one of the preparation methods described in claims 1-5.

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