PE pipe and preparation method thereof

Abstract

The invention relates to the technical field of PE pipe machining, and particularly discloses a PE pipe and a preparation method thereof. The PE pipe is prepared from the following raw materials in parts by mass: 60-80 parts of high-density polyethylene, 20-35 parts of polyphenyl ether, 10-20 parts of ethylene propylene diene monomer, 3-8 parts of a polyurethane prepolymer, 2-4 parts of maleic anhydride grafted polyethylene, 2-4 parts of 4, 4 '-diphenylmethane diisocyanate, 1-3 parts of a coupling agent and 1-3 parts of a coupling agent. The composite material is prepared from the following components in parts by mass: 0.5 to 1.5 parts of 2, 5-diamino-2-thiouracil, 5 to 12 parts of silicon-based microcapsule coated basalt particles, 0.5 to 2 parts of an antioxidant, 0.1 to 1 part of a light stabilizer and 1.5 to 2.5 parts of glyceryl stearate. The PE pipe prepared in the invention has good mechanical properties and aging resistance.

Description

Technical Field

[0001] This application relates to the technical field of PE pipe processing, and more specifically, it relates to a PE pipe and a preparation method thereof. Background Art

[0002] PE pipes, namely polyethylene pipes, as a common plastic pipe material, are mainly used in fields such as water supply, drainage, and gas transmission. However, they have some performance shortcomings. In terms of mechanical properties, the strength of PE pipes is limited. Especially when facing relatively large pressure or impact force, they are prone to deformation and even rupture. In terms of high-temperature resistance, PE pipes are extremely prone to deformation and softening in a high-temperature environment, which not only seriously shortens their service life but also poses a great threat to the safety performance during use. At the same time, during long-term use, PE pipes are affected by a variety of factors such as ultraviolet rays, oxygen, and heat, and the aging problem is relatively prominent, resulting in a continuous decline in the pipe performance. In addition, the pressure resistance of PE pipes is relatively low, making it difficult to meet some special usage scenarios with high pressure and large flow. In a high-pressure environment, PE pipes are prone to accidents such as rupture and leakage, bringing serious hidden dangers to the safe and stable operation of water supply and other systems.

[0003] The patent application document with the publication number CN107540916A discloses a PE pipe for municipal drainage. The raw materials are in parts by weight: 100 parts of polyethylene, 8 - 10 parts of polycarbonate, 3 - 6 parts of silicon carbide whiskers, 1 - 4 parts of titanium dioxide, 0.5 - 1 part of graphene, 1 - 2 parts of mineral oil, 0.5 - 1 part of nucleating agent, 1 - 2 parts of compatibilizer, and 1 - 2 parts of antioxidant.

[0004] In the above technical solution, silicon carbide whiskers are directly added to the polyethylene matrix. Due to their special microstructure and surface properties, it is difficult to ensure their uniform and effective dispersion during the preparation process. When the dispersion is uneven, there will be insufficient strengthening effect in some areas inside the pipe. These weak areas are not only prone to deformation when stressed, but also with the continuous deformation and stress concentration, microcracks will gradually form inside the materials of these weak areas, greatly reducing the overall mechanical properties of the pipe. Summary of the Invention

[0005] In order to improve the tensile performance and compressive performance of PE pipes, this application provides a PE pipe and a preparation method thereof.

[0006] In the first aspect, this application provides a PE pipe, adopting the following technical solution: A PE pipe is made of the following raw materials in parts by mass: 60-80 parts by mass of high-density polyethylene, 20-35 parts by mass of polyphenylene ether, 10-20 parts by mass of ethylene propylene diene monomer rubber, 3-8 parts by mass of polyurethane prepolymer, 2-4 parts by mass of maleic anhydride grafted polyethylene, 0.5-1.5 parts by mass of 4,5-diamino-2-thiouracil, 5-12 parts by mass of silicon-based microcapsule coated basalt particles, 0.5-2 parts by mass of antioxidant, 0.1-1 part by mass of light stabilizer, and 1.5-2.5 parts by mass of glyceryl stearate.

[0007] In this technical solution, maleic anhydride grafted polyethylene and polyurethane prepolymer form a physical crosslinking network with high-density polyethylene, polyphenylene ether, and ethylene propylene diene monomer rubber through the flexible winding of molecular chains. This synergistic effect of bonding and physical winding effectively shortens the interfacial distance between components, significantly enhances the interfacial bonding force, and thus realizes the tight integration of the material system. When subjected to impact and high-temperature environments, the synergistic effect of each component is strengthened, effectively inhibiting the phase separation phenomenon, and thus ensuring the overall performance of the pipe. Silicon-based microcapsule coated basalt particles can be evenly dispersed in the PE pipe system. When the pipe is subjected to loads such as impact, compression, and shear, these loads will be transmitted to the basalt particles in the form of shear components, causing the basalt particles to share part of the external load acting on the pipe matrix, thereby significantly improving the ring stiffness and overall strength of the pipe.

[0008] Based on maleic anhydride grafted polyethylene and polyurethane prepolymer, 4,5-diamino-2-thiouracil can form a certain degree of bonding with the crosslinking network formed by high-density polyethylene, polyphenylene ether, and ethylene propylene diene monomer rubber, etc., thereby constructing covalent bond connections between different polymer molecular chains. This is the basis for the formation of a quasi-supramolecular structure. At the same time, a conjugated system similar to the pyrimidine ring can also produce π-π stacking interactions to assist in the formation of the quasi-supramolecular structure. This structure can play a "molecular bridge" role between different polymer molecular chains such as high-density polyethylene, polyphenylene ether, and ethylene propylene diene monomer rubber, increasing the cohesive energy between molecular chains, making the combination between polymers more compact, and thus comprehensively improving the mechanical properties of the entire material, such as tensile strength, tear strength, etc., and significantly enhancing the tensile and tear resistance of the PE pipe.

[0009] In addition, the interactions such as hydrogen bonds in the quasi-supramolecular structure have a certain degree of dynamic reversibility. When the PE pipe is subjected to a small external force and causes minor damage, the formed quasi-supramolecular structure will, under the stimulation of microenvironmental changes, dynamically adjust the hydrogen bond interaction network through a reversible hydrogen bond recombination mechanism, prompting the surrounding polymer molecular chains to rearrange and fill the cracks, achieving a certain degree of self-repair. This dynamic response characteristic helps to restore some of the material's properties, greatly improving the durability and reliability of the pipe.

[0010] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

[0011] Preferably, the light stabilizer is 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol.

[0012] Preferably, the method for preparing the silicon-based microcapsule-coated basalt particles includes the following steps: (1) Mix tetraethyl orthosilicate, organic solvent, silane coupling agent and water evenly, adjust the pH to 8-10, heat up to 40-60 °C, and react for 4-8 h to obtain a sol; (2) Immerse the basalt particles in the sol, mix evenly, heat up to 40-80 °C, react for 12-24 h, cool down, separate the solid and liquid, dry, and sinter to obtain silicon-based microcapsule-coated basalt particles; The mass ratio of tetraethyl orthosilicate, organic solvent, silane coupling agent, water and basalt particles is 1:(3-6):(0.02-0.05):(1.5-2.5):(2-5).

[0013] In this technical solution, on the one hand, the silica gel film formed after the hydrolysis and polycondensation of tetraethyl orthosilicate changes its surface from the original strong hydrophilicity to a certain degree of organophilicity. This change in organophilicity enhances the affinity between the basalt particles and the organic material such as polyethylene. During the mixing process, it can better interact with polyethylene molecules, reduce the agglomeration phenomenon caused by surface property differences, and is conducive to uniform dispersion in polyethylene. On the other hand, after the treatment with tetraethyl orthosilicate, a large number of active groups such as hydroxyl groups on the surface of the silica gel film can not only form bonds with elements such as silicon and aluminum on the surface of the basalt particles, but also physically entangle or mechanically interlock with the molecular chains of high-density polyethylene and other molecules. These interfacial interactions significantly enhance the compatibility between basalt and polyethylene, making the two no longer a simple physical mixture, but a composite system with molecular-level interactions at the molecular level. This molecular-level interaction effectively inhibits the agglomeration and sedimentation of basalt particles in the polyethylene matrix, making them maintain a relatively stable and uniform distribution state in the polyethylene matrix.

[0014] Preferably, the PE pipe also includes 1.5-4.5 parts by mass of modified konjac polysaccharide.

[0015] Preferably, the method for preparing the modified konjac polysaccharide includes the following steps: Mix konjac polysaccharide and solvent evenly, add stearic acid and p-toluenesulfonic acid, heat up to 80-120 °C, react for 6-12 h, cool to room temperature, separate the solid and liquid, and dry to obtain modified konjac polysaccharide; The mass ratio of konjac polysaccharide to stearic acid is 1:(3-5).

[0016] Preferably, the solvent is N,N-dimethylformamide, and the mass ratio of konjac polysaccharide to N,N-dimethylformamide is 1:(5-7).

[0017] Preferably, the dosage of p-toluenesulfonic acid is 0.8%-2% of the total mass of konjac polysaccharide and stearic acid.

[0018] In this technical solution, by adding the modified konjac polysaccharide into the PE pipe system, the polysaccharide chains in its molecules can play a role similar to that of a "molecular bridge" in the PE pipe substrate, not only making the binding between polymer chains tighter, but also promoting the uniform dispersion of stress, thereby improving the mechanical properties of the PE pipe. At the same time, its hydrophobic long-chain alkyl groups are miscible with non-polar polymers such as high-density polyethylene and polyphenylene ether, which can improve the interfacial bonding between components and enhance the overall structural stability and mechanical properties.

[0019] Preferably, the PE pipe further comprises 8-10 parts by mass of polyisobutylene.

[0020] In this technical solution, when polyisobutylene is added to the PE pipe, the polyisobutylene molecules can be relatively easily inserted between the molecular chains of polymers such as high-density polyethylene. The side groups and other structures on the polyisobutylene molecular chains can play a filling role in the gaps between the molecular chains of polymers such as high-density polyethylene, which can not only enhance the binding strength between different polymers, but also enhance the interaction between polymer molecular chains, and the movement of molecular chains is restricted to a certain extent, thereby improving the anti-aging performance. However, the flexibility of polyisobutylene itself plays a compensatory role, so overall the material will not become brittle due to the increase in rigidity, but can still maintain good ductility to a certain extent, making the elongation at break stable or increased within a certain range.

[0021] Preferably, the PE pipe further comprises 6-8 parts by mass of polybutylene adipate.

[0022] In this technical solution, when polybutylene adipate is added to the PE pipe, the flexibility and low-temperature resistance of the PE pipe can be improved, so that it can still maintain good use performance in a cold environment and reduce the risk of brittle fracture.

[0023] In the second aspect, the present application provides a method for preparing the above-mentioned PE pipe, comprising the following steps: S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer, mix evenly to obtain a premix; S2: Transfer the premix to an internal mixer, heat it up to 140 - 160 °C, after mixing for 10 - 15 min, add 4,5 - diamino - 2 - thiouracil, silicon - based microcapsule - coated basalt particles, antioxidant, light stabilizer and glyceryl stearate, continue to mix for 10 - 15 min, and then cool to obtain the extruded material. S3: Convey the extruded material to the feed inlet of a twin - screw extruder, perform extrusion molding, sizing, traction, cooling and shaping, and cutting to obtain the PE pipe.

[0024] Preferably, in the twin - screw extruder, the screw speed is 100 - 200 r / min. From the feed inlet to the discharge outlet, the temperature settings for each zone are as follows: zone 1: 160 - 170 °C, zone 2: 170 - 180 °C, zone 3: 180 - 190 °C, and zone 4: 190 - 200 °C.

[0025] Preferably, in step S2, after adding 4,5 - diamino - 2 - thiouracil, it further includes the step of adding modified konjac polysaccharide.

[0026] Preferably, in step S1, when adding ethylene - propylene - diene monomer (EPDM), it further includes the step of adding polyisobutylene.

[0027] Preferably, in step S1, when adding ethylene - propylene - diene monomer (EPDM), it further includes the step of adding poly(butylene adipate).

[0028] In summary, the present application has the following beneficial effects: 1. The present application uses maleic anhydride - grafted polyethylene and polyurethane prepolymer to jointly strengthen the bonding force between high - density polyethylene, polyphenylene ether and ethylene - propylene - diene monomer (EPDM), improve the overall cohesion and mechanical properties of the PE pipe substrate, and add 4,5 - diamino - 2 - thiouracil to assist in strengthening, guiding the formation of a quasi - hyperbranched structure inside the material system, enhancing the interaction between the molecular chains of the PE pipe substrate, further improving the mechanical properties of the PE pipe substrate, such as tensile strength, bending strength, impact strength, etc., and at the same time improving the processing performance of the PE pipe substrate, making it easier to flow and form during processing such as extrusion molding, reducing the generation of defects.

[0029] 2. The present application uses silicon - based microcapsule - coated basalt particles. The active groups on the surface of the microcapsules can interact with the molecular chains of the PE pipe substrate and be closely connected, such as hydrogen bonds, van der Waals forces, etc., thereby enhancing the interfacial bonding force and compatibility between the particles and the matrix. During the processing, the silicon - based microcapsule - coated basalt particles can be evenly distributed in the pipe material, giving full play to their strengthening effect, and improving the mechanical properties and stability of the PE pipe.

[0030] 3. This application preferably uses modified konjac polysaccharide. Its rich polar groups can form interactions such as hydrogen bonds and van der Waals forces with other components in the PE pipe substrate, such as high-density polyethylene, polyphenylene ether, and ethylene propylene diene monomer, making the binding between polymer chains in the substrate closer and further enhancing the mechanical properties of the PE pipe. Detailed implementation manners

[0031] The following further elaborates on this application with reference to examples.

[0032] Unless otherwise specified, the raw materials in the examples, preparation examples, and comparative examples of this application are all commercially available.

[0033] In the following examples, preparation examples, and comparative examples: The basalt particles are processed through the following steps before use: After cleaning, drying, and grinding the basalt particles, first pass them through a 500-mesh sieve and take the undersize for standby; The polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene ether), and its molecular weight distribution is 30,000 to 50,000; The polyurethane prepolymer is a polyether-type MDI-capped polyurethane prepolymer (abbreviated as polyurethane prepolymer), with an -NCO content of about 8% to 10% and a molecular weight distribution of about 2000; The light stabilizer is 2-(2H-benzotriazol-2-yl)-4,6-ditert-amylphenol (abbreviated as UV-328).

[0034] Preparation Examples 1 to 3: Silicon-based microcapsule-coated basalt particles Preparation Example 1 This preparation example provides a method for preparing silicon-based microcapsule-coated basalt particles, including the following steps: (1) Add 300 g of absolute ethanol to a reactor, then add 100 g of tetraethyl orthosilicate and stir to mix evenly. Then add 2 g of γ-aminopropyltriethoxysilane, continue to stir and mix evenly, slowly add 150 g of deionized water, and adjust the pH to 8 - 8.5 with 5% potassium hydroxide by mass. Heat to 40 °C and react for 8 h to obtain a uniformly distributed sol; (2) Slowly pour 200 g of basalt particles into the above-prepared sol, stir and mix evenly, heat to 40 °C, react for 24 h, naturally cool to room temperature, filter, wash twice with absolute ethanol, transfer to a drying oven, dry to constant weight at 80 °C, then transfer to a sintering furnace, heat to 600 °C at a rate of 4 °C / min, sinter for 3 h, and cool to room temperature with the furnace. Slightly grind and disperse for standby.

[0035] Preparation Example 2 This preparation example provides a method for preparing silicon-based microcapsule-coated basalt particles, including the following steps: (1) Add 600 g of absolute ethanol into a reactor, then add 100 g of tetraethyl orthosilicate and stir to mix evenly. Then add 5 g of γ-aminopropyltriethoxysilane, continue to stir and mix evenly, slowly add 250 g of deionized water, and adjust the pH to the range of 9.5 - 10 with 5% potassium hydroxide by mass fraction. Heat up to 60 °C and react for 4 h to obtain a sol with uniform distribution; (2) Slowly pour 500 g of basalt particles into the sol prepared above, stir and mix evenly, heat up to 80 °C, react for 12 h, naturally cool to room temperature, filter, wash twice with absolute ethanol, transfer to a drying oven, dry to constant weight at 80 °C, then transfer to a sintering furnace, heat up to 400 °C at a rate of 2 °C / min, sinter for 2 h, cool to room temperature with the furnace, and slightly grind and disperse for standby.

[0036] Preparation Example 3 This preparation example provides a preparation method of silicon-based microcapsule-coated basalt particles, including the following steps: (1) Add 450 g of absolute ethanol into a reactor, then add 100 g of tetraethyl orthosilicate and stir to mix evenly. Then add 4 g of γ-aminopropyltriethoxysilane, continue to stir and mix evenly, slowly add 200 g of deionized water, and adjust the pH to the range of 8.5 - 9.5 with 5% potassium hydroxide by mass fraction. Heat up to 50 °C and react for 6 h to obtain a sol with uniform distribution; (2) Slowly pour 300 g of basalt particles into the sol prepared above, stir and mix evenly, heat up to 70 °C, react for 18 h, naturally cool to room temperature, filter, wash twice with absolute ethanol, transfer to a drying oven, dry to constant weight at 80 °C, then transfer to a sintering furnace, heat up to 500 °C at a rate of 3 °C / min, sinter for 4 h, cool to room temperature with the furnace, and slightly grind and disperse for standby.

[0037] Modified konjac polysaccharide in Preparation Examples 4 - 6 Preparation Example 4 This preparation example provides a preparation method of modified konjac polysaccharide, including the following steps: Add 500 g of N,N-dimethylformamide into a reactor, then add 100 g of konjac polysaccharide and stir until completely dissolved. During stirring, heat up to about 40 °C, then add 300 g of stearic acid and stir to mix evenly. Then add 8 g of p-toluenesulfonic acid, mix evenly, heat up to 80 °C, react for 12 h, cool to room temperature, add absolute ethanol until no precipitation occurs, filter, wash twice with absolute ethanol, transfer to a drying oven, dry to constant weight at 80 °C, and slightly grind and fractionate to obtain the modified konjac polysaccharide.

[0038] Take 5 g of the modified konjac polysaccharide and place it in a beaker. Then add 10 g of deionized water. Let it stand at 25 °C for 12 h. After filtration, gently press the surface of the modified konjac polysaccharide with filter paper 3 times, replacing the filter paper each time. Then weigh the substance containing the modified konjac polysaccharide after water absorption, and calculate that the water absorption rate of the modified konjac polysaccharide is about 1%.

[0039] Preparation Example 5 This preparation example provides a method for preparing a modified konjac polysaccharide, which includes the following steps: Add 700 g of N,N-dimethylformamide to a reactor, then add 100 g of konjac polysaccharide and stir until completely dissolved. During stirring, heat up to about 40 °C, then add 500 g of stearic acid and stir to mix evenly. Then add 4.8 g of p-toluenesulfonic acid, mix evenly, heat up to 120 °C, react for 6 h, cool to room temperature, add absolute ethanol until no precipitate is formed, filter, wash with absolute ethanol 2 times, transfer to a drying oven, and dry at 80 °C to constant weight, and gently grind into fractions to obtain the modified konjac polysaccharide.

[0040] Take 5 g of the modified konjac polysaccharide and place it in a beaker. Then add 10 g of deionized water. Let it stand at 25 °C for 12 h. After filtration, gently press the surface of the modified konjac polysaccharide with filter paper 3 times, replacing the filter paper each time. Then weigh the substance containing the modified konjac polysaccharide after water absorption, and calculate that the water absorption rate of the modified konjac polysaccharide is about 0.7%.

[0041] Preparation Example 6 This preparation example provides a method for preparing a modified konjac polysaccharide, which includes the following steps: Add 600 g of N,N-dimethylformamide to a reactor, then add 100 g of konjac polysaccharide and stir until completely dissolved. During stirring, heat up to about 40 °C, then add 400 g of stearic acid and stir to mix evenly. Then add 6 g of p-toluenesulfonic acid, mix evenly, heat up to 100 °C, react for 10 h, cool to room temperature, add absolute ethanol until no precipitate is formed, filter, wash with absolute ethanol 2 times, transfer to a drying oven, and dry at 80 °C to constant weight, and gently grind into fractions to obtain the modified konjac polysaccharide.

[0042] Take 5 g of the modified konjac polysaccharide and place it in a beaker. Then add 10 g of deionized water. Let it stand at 25 °C for 12 h. After filtration, gently press the surface of the modified konjac polysaccharide with filter paper 3 times, replacing the filter paper each time. Then weigh the substance containing the modified konjac polysaccharide after water absorption, and calculate that the water absorption rate of the modified konjac polysaccharide is about 0.8%.

[0043] Example 1 This embodiment provides a PE pipe, which is made of the following raw materials in parts by mass: 600 g of high-density polyethylene, 200 g of polyphenylene ether, 100 g of ethylene propylene diene monomer rubber, 30 g of polyurethane prepolymer, 20 g of maleic anhydride grafted polyethylene, 5 g of 4,5-diamino-2-thiouracil, 50 g of silicon-based microcapsule coated basalt particles, 5 g of antioxidant, 1 g of light stabilizer, and 15 g of glyceryl stearate.

[0044] Among them, the silicon-based microcapsule coated basalt particles are from Preparation Example 1; the antioxidant is antioxidant 1010.

[0045] This embodiment also provides a preparation method of the above-mentioned PE pipe, which includes the following steps: S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer according to the above mass, and mix at a speed of 800 r / min for 8 min to obtain a premix. S2: Transfer the premix to an internal mixer, heat up to 140 °C, mix for 10 min, then add 4,5-diamino-2-thiouracil, silicon-based microcapsule coated basalt particles, antioxidant, light stabilizer, and glyceryl stearate according to the above mass, keep at 140 °C, continue to mix for 10 min, and naturally cool to room temperature to obtain an extrusion material. S3: Convey the extrusion material to the feed port of a twin-screw extruder, install the corresponding die, then start the twin-screw extruder. Set the screw speed to 100 r / min, and adjust the temperatures of each zone of the extruder: Zone 1 is 160 °C, Zone 2 is 170 °C, Zone 3 is 180 °C, and Zone 4 is 190 °C. After extrusion, immediately enter the sizing device. The sized pipe is pulled by a traction device at a speed of 1 m / min into a cooling water tank, and is rapidly cooled and shaped in the cooling water tank. The cooling water temperature is controlled within the range of 15 - 25 °C, and then through a cutting device, it is cut according to a predetermined length to obtain a finished PE pipe.

[0046] Example 2 This embodiment provides a PE pipe, which is made of the following raw materials in parts by mass: 800 g of high-density polyethylene, 350 g of polyphenylene ether, 200 g of ethylene propylene diene monomer rubber, 80 g of polyurethane prepolymer, 40 g of maleic anhydride grafted polyethylene, 15 g of 4,5-diamino-2-thiouracil, 120 g of silicon-based microcapsule coated basalt particles, 20 g of antioxidant, 10 g of light stabilizer, and 25 g of glyceryl stearate.

[0047] Among them, the silicon-based microcapsule coated basalt particles are from Preparation Example 2; the antioxidant is 15 g of antioxidant 1010 and 5 g of antioxidant 168.

[0048] This embodiment also provides a preparation method of the above-mentioned PE pipe, which includes the following steps: S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer according to the above quality, mix at a speed of 800 r / min for 12 min to obtain a premix. S2: Transfer the premix to an internal mixer, heat up to 160 °C, after mixing for 15 min, add 4,5-diamino-2-thiouracil, silicon-based microcapsule-coated basalt particles, antioxidant, light stabilizer, and glyceryl stearate according to the above quality, maintain at 160 °C, continue to mix for 15 min, and naturally cool to room temperature to obtain an extrusion material. S3: Convey the extrusion material to the feed inlet of a twin-screw extruder. After installing the corresponding die, start the twin-screw extruder. Set the screw speed to 200 r / min, and adjust the temperatures of each zone of the extruder: zone 1 at 170 °C, zone 2 at 180 °C, zone 3 at 190 °C, and zone 4 at 200 °C. After extrusion, immediately enter the sizing device. The sized pipe is pulled by a traction device at a speed of 2 m / min into a cooling water tank, and is rapidly cooled and shaped in the cooling water tank. The cooling water temperature is controlled within the range of 15 - 25 °C. Then, it is cut by a cutting device according to a predetermined length to obtain the finished PE pipe.

[0049] Example 3 This example provides a PE pipe made from the following raw materials in parts by mass: 700 g of high-density polyethylene, 300 g of polyphenylene ether, 180 g of ethylene propylene diene monomer rubber, 60 g of polyurethane prepolymer, 30 g of maleic anhydride grafted polyethylene, 10 g of 4,5-diamino-2-thiouracil, 80 g of silicon-based microcapsule-coated basalt particles, 13 g of antioxidant, 6 g of light stabilizer, and 20 g of glyceryl stearate.

[0050] Among them, the silicon-based microcapsule-coated basalt particles are from Preparation Example 3; the antioxidant is 10 g of antioxidant 1010 and 3 g of antioxidant 168.

[0051] This example also provides a method for preparing the above PE pipe, including the following steps: S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer according to the above quality, mix at a speed of 800 r / min for 10 min to obtain a premix. S2: Transfer the premix to an internal mixer, heat up to 150 °C, after mixing for 13 min, add 4,5-diamino-2-thiouracil, silicon-based microcapsule-coated basalt particles, antioxidant, light stabilizer, and glyceryl stearate according to the above quality, maintain at 150 °C, continue to mix for 13 min, and naturally cool to room temperature to obtain an extrusion material. S3: Feed the extruded material to the feed inlet of the twin-screw extruder. After installing the corresponding die, start the twin-screw extruder. Set the screw speed to 120 r / min and adjust the temperatures of each zone of the extruder: Zone 1 at 165 °C, Zone 2 at 175 °C, Zone 3 at 185 °C, and Zone 4 at 195 °C. After extrusion, immediately enter the sizing device. The sized pipe is pulled by the traction equipment at a speed of 1.5 m / min into the cooling water tank, and is quickly cooled and shaped in the cooling water tank. The cooling water temperature is controlled within the range of 15 - 25 °C. Then, it is cut by the cutting equipment according to the predetermined length to obtain the finished PE pipe.

[0052] Example 4 This example provides a PE pipe made from the following raw materials in parts by mass: 700 g of high-density polyethylene, 300 g of polyphenylene ether, 180 g of ethylene propylene diene monomer rubber, 60 g of polyurethane prepolymer, 30 g of maleic anhydride grafted polyethylene, 10 g of 4,5-diamino-2-thiouracil, 80 g of silicon-based microcapsule-coated basalt particles, 13 g of antioxidant, 6 g of light stabilizer, 20 g of glyceryl stearate, and 15 g of modified konjac polysaccharide.

[0053] Among them, the silicon-based microcapsule-coated basalt particles are from Preparation Example 3; the antioxidant is 10 g of antioxidant 1010 and 3 g of antioxidant 168; the modified konjac polysaccharide is from Preparation Example 4.

[0054] This example also provides a method for preparing the above-mentioned PE pipe, including the following steps: S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyurethane prepolymer, and maleic anhydride grafted polyethylene to the high-speed mixer according to the above masses, and mix at a speed of 800 r / min for 10 min to obtain a premix. S2: Transfer the premix to the internal mixer, heat it up to 150 °C, mix for 13 min, then add 4,5-diamino-2-thiouracil, modified konjac polysaccharide, silicon-based microcapsule-coated basalt particles, antioxidant, light stabilizer, and glyceryl stearate according to the above masses, keep at 150 °C, and continue to mix for 13 min. Naturally cool to room temperature to obtain the extruded material. S3: Feed the extruded material to the feed inlet of the twin-screw extruder. After installing the corresponding die, start the twin-screw extruder. Set the screw speed to 120 r / min and adjust the temperatures of each zone of the extruder: Zone 1 at 170 °C, Zone 2 at 180 °C, Zone 3 at 190 °C, and Zone 4 at 200 °C. After extrusion, immediately enter the sizing device. The sized pipe is pulled by the traction equipment at a speed of 1.5 m / min into the cooling water tank, and is quickly cooled and shaped in the cooling water tank. The cooling water temperature is controlled within the range of 15 - 25 °C. Then, it is cut by the cutting equipment according to the predetermined length to obtain the finished PE pipe.

[0055] Example 5 The difference between this example and Example 4 is that: The dosage of the modified konjac polysaccharide is 30 g; the modified konjac polysaccharide is from Preparation Example 5.

[0056] Others are the same as in Example 4.

[0057] Example 6 This example provides a PE pipe, which is made of the following raw materials in parts by mass: 700 g of high-density polyethylene, 300 g of polyphenylene ether, 180 g of ethylene propylene diene monomer, 60 g of polyurethane prepolymer, 30 g of maleic anhydride grafted polyethylene, 10 g of 4,5-diamino-2-thiouracil, 80 g of silicon-based microcapsule-coated basalt particles, 13 g of antioxidant, 6 g of light stabilizer, 20 g of glyceryl stearate, 45 g of modified konjac polysaccharide, and 80 g of polyisobutylene.

[0058] Among them, the silicon-based microcapsule-coated basalt particles are from Preparation Example 2; the antioxidant is 8 g of antioxidant 1010 and 5 g of antioxidant 168; the modified konjac polysaccharide is from Preparation Example 6.

[0059] This example also provides a preparation method of the above PE pipe, which includes the following steps: S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer, polyisobutylene, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer according to the above masses, and mix at a speed of 800 r / min for 12 min to obtain a premix; S2: Transfer the premix to an internal mixer, heat up to 150 °C, mix for 13 min, then add 4,5-diamino-2-thiouracil, modified konjac polysaccharide, silicon-based microcapsule-coated basalt particles, antioxidant, light stabilizer, and glyceryl stearate according to the above masses, keep at 150 °C, continue to mix for 13 min, and naturally cool to room temperature to obtain an extrusion material; S3: Convey the extrusion material to the feed inlet of a twin-screw extruder, install the corresponding die, start the twin-screw extruder, Set the screw speed to 120 r / min, and adjust the temperatures of each zone of the extruder: Zone 1 is 170 °C, Zone 2 is 180 °C, Zone 3 is 190 °C, and Zone 4 is 200 °C. After extrusion, immediately enter the sizing device, and the sized pipe is pulled by a traction device at a speed of 1.5 m / min into a cooling water tank, and is quickly cooled and shaped in the cooling water tank. The cooling water temperature is controlled within the range of 15-25 °C, and then through a cutting device, it is cut according to a predetermined length to obtain a finished PE pipe.

[0060] Example 7 The difference between this example and Example 6 is that: The dosage of polyisobutene is 100 g; the modified konjac polysaccharide is from Preparation Example 5.

[0061] Others are the same as in Example 6.

[0062] Example 8 This example provides a PE pipe, which is made from the following raw materials in parts by mass: 700 g of high-density polyethylene, 300 g of polyphenylene ether, 180 g of ethylene propylene diene monomer rubber, 60 g of polyurethane prepolymer, 30 g of maleic anhydride grafted polyethylene, 10 g of 4,5-diamino-2-thiouracil, 80 g of silicon-based microcapsule coated basalt particles, 13 g of antioxidant, 6 g of light stabilizer, 20 g of glyceryl stearate, 45 g of modified konjac polysaccharide, 100 g of polyisobutene and 60 g of polybutylene adipate.

[0063] Among them, the silicon-based microcapsule coated basalt particles are from Preparation Example 2; the antioxidant is 8 g of antioxidant 1010 and 5 g of antioxidant 168; the modified konjac polysaccharide is from Preparation Example 5.

[0064] This example also provides a preparation method of the above PE pipe, which includes the following steps: S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyisobutene, polybutylene adipate, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer according to the above masses, and mix at a speed of 800 r / min for 12 min to obtain a premix. S2: Transfer the premix to an internal mixer, heat it up to 150 °C, mix for 13 min, then add 4,5-diamino-2-thiouracil, modified konjac polysaccharide, silicon-based microcapsule coated basalt particles, antioxidant, light stabilizer, and glyceryl stearate according to the above masses, keep at 150 °C, continue to mix for 13 min, and naturally cool to room temperature to obtain an extrusion material. S3: Convey the extrusion material to the feed inlet of a twin-screw extruder, install the corresponding die, start the twin-screw extruder, Set the screw speed to 120 r / min, and adjust the temperatures of each zone of the extruder: Zone 1 is 170 °C, Zone 2 is 180 °C, Zone 3 is 190 °C, and Zone 4 is 200 °C. After extrusion, immediately enter the sizing device. The sized pipe is pulled by a traction device at a speed of 1.5 m / min into a cooling water tank, and is quickly cooled and shaped in the cooling water tank. The cooling water temperature is controlled within the range of 15 - 25 °C, and then through a cutting device, it is cut according to a predetermined length to obtain the finished PE pipe.

[0065] Example 9 The difference between this example and Example 8 is that: The dosage of polybutylene adipate is 80 g.

[0066] Others are the same as in Example 8.

[0067] Comparative Example 1 The difference between this comparative example and Example 1 is that: Basalt particles of equal mass were directly added. Before use, the basalt particles were subjected to the following pretreatment steps: After washing, drying, and grinding the basalt particles, they were first passed through a 500-mesh sieve, and the undersize was taken for standby.

[0068] Others were the same as in Example 1.

[0069] Comparative Example 2 The difference between this comparative example and Example 1 is that: Basalt particles of equal mass were directly added. Before use, the basalt particles were subjected to the following pretreatment steps: After washing, drying to constant weight, and grinding the basalt particles, they were first passed through a 500-mesh sieve, and the undersize was taken to obtain preliminarily treated basalt particles. The preliminarily treated basalt particles were added to a silane coupling agent solution with a pH of 4 - 5, stirred and mixed for 4 h, then the pH was adjusted to neutral with 5% ammonia water by mass fraction, filtered, washed twice with absolute ethanol, transferred to a drying oven, and dried to constant weight at 80 °C to obtain the product.

[0070] Among them, the mass ratio of the silane coupling agent solution to the preliminarily treated basalt particles was 5:1.

[0071] The silane coupling agent solution included silane coupling agent KH550, ethanol, and water. The mass fraction of silane coupling agent KH550 was 2%, the mass fraction of ethanol was 78%, and the rest was deionized water.

[0072] Comparative Example 3 The difference between this comparative example and Example 1 is that: 4,5-Diamino-2-thiouracil was not added.

[0073] Others were the same as in Example 1.

[0074] Comparative Example 4 The polyurethane prepolymer was not added, and the amount of maleic anhydride grafted polyethylene was adjusted to 50 g.

[0075] Comparative Example 5 The difference between this comparative example and Example 1 is that: Polyphenylene ether was not added.

[0076] Others were the same as in Example 1.

[0077] Performance detection test 1. Performance detection in the first stage Mechanical property test: (1) Tensile strength and elongation at break: According to GB / T 1040-2018, the finished PE pipes in Examples 1-9 and Comparative Examples 1-5 were respectively cut into dumbbell-shaped specimens. The surface of the specimens should be smooth, without scratches, bubbles and other defects. Five parallel specimens were prepared for each group. Then, an electronic universal testing machine was used to test the tensile strength and elongation at break of each specimen, and the average value was taken as the tensile strength and elongation at break of the specimens in this group. The test results are shown in Table 1.

[0078] (2) Compressive strength: According to GB / T 9647-2015, specimens with a length of (300±10) mm were respectively intercepted from the finished PE pipes in Examples 1-9 and Comparative Examples 1-5. Five parallel specimens were prepared for each group. Then, a pipe ring stiffness testing machine was used to calculate the ring stiffness of each specimen, and the average value was taken as the compressive strength of the specimens in this group. The test results are shown in Table 1.

[0079] (3) Impact resistance: According to GB / T 14152-2001, specimens with a length of (200±10) mm were respectively intercepted from the finished PE pipes in Examples 1-9 and Comparative Examples 1-5. Ten parallel specimens were prepared for each group. A falling weight impact testing machine was used, with the weight of the falling weight being 12 kg and the falling height of the falling weight being within the range of 2 m±0.02 m. The falling weight was allowed to freely fall and impact the specimen, and the impact results of the specimen (counting the number of fractures) were observed and recorded. The test results are shown in Table 1.

[0080] Aging resistance performance test: According to GB / T3512-2001, the finished PE pipes in Examples 1-9 and Comparative Examples 1-5 were respectively cut into dumbbell-shaped specimens. After setting the temperature of the aging chamber to 100 °C, the aging chamber was started, and its internal temperature was evenly increased and stabilized within the range of the target temperature 100 °C±2 °C. The preheating time was not less than 1 hour to ensure the stability of the temperature field in the aging chamber. The test specimens were placed in the aging chamber for experiments. After 72 h, the specimens were taken out, and the aged specimens were transferred to an environment with a temperature of 23±2 °C and a relative humidity of 50±5% for conditioning. The conditioning time was 48 h. Then, an electronic universal testing machine was used to test the tensile strength of the aged specimens. Five parallel specimens of the aged specimens of each sample were tested, and the average value was taken as the tensile strength of the aged sample. The test results are shown in Table 1.

[0081] Table 1 Performance test data of the finished PE pipes in Examples 1-9 and Comparative Examples 1-5

[0082] 2. Second-stage performance testing Low-temperature resistance performance test: According to GB / T3512-2001, the finished PE pipes in Examples 5 to 9 were respectively cut into dumbbell-shaped specimens. After setting the temperatures of the low-temperature aging oven to -20°C and 0°C respectively, start the low-temperature aging oven to make the internal temperature drop uniformly and stabilize within the target temperatures of -20±2°C and 0±2°C. The pre-cooling time was not less than 1 hour to ensure the stability of the temperature field in the low-temperature aging oven. Place the test specimens in the low-temperature aging oven for experiments. After 72 hours, take out the specimens, transfer the specimens after low-temperature aging to an environment with a temperature of 23±2°C and a relative humidity of 50±5% for conditioning. The conditioning time was 48 hours. Then test the low-temperature impact resistance. Prepare 10 parallel specimens for each group, observe and record the impact results of the specimens (count the number of fractures). The test results are shown in Table 2.

[0083] Table 2 Detection data of the impact resistance of the finished PE pipes in Examples 5 to 9

[0084] Analysis of the detection data in Table 1 shows that: From Example 1 and Comparative Examples 1 to 5, it can be seen that the interfacial compatibility between the silicon-based microcapsule-coated basalt particles and matrix polymers such as high-density polyethylene is better, and they are combined more tightly, which can give full play to the strengthening effect, effectively disperse stress and bear pressure. 4,5-Diamino-2-thiouracil and polyurethane prepolymer enhanced the binding strength between different polymer molecules to a certain extent, thus significantly improving the tensile strength and compressive strength of the PE pipe. And polyphenylene ether helps to build a stable structural framework inside the material, and cooperate with components such as silicon-based microcapsule-coated basalt particles to better disperse and resist external pressure.

[0085] From Examples 1 to 9, it can be seen that with the addition of modified konjac polysaccharide, polyisobutene, and polybutylene adipate, both the tensile strength and the elongation at break show a gradually increasing trend. Modified konjac polysaccharide contains a large number of active groups such as hydroxyl groups, which can form hydrogen bonds or physical entanglements with other polymer molecules, enhancing the intermolecular force, thereby improving the tensile strength. Polyisobutene can penetrate between the molecular chains of other polymers, not only endowing the PE pipe with good flexibility, but also connecting different polymer molecules, improving the tensile strength to a certain extent. Polybutylene adipate can form certain interactions with other molecules through ester groups, improve the overall structural stability of the material, and thus enhance the tensile strength. In addition, the addition of polyisobutene and polybutylene adipate also enhanced the impact resistance of the PE pipe at -20°C.

[0086] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A PE pipe, characterized in that: The invention is prepared from the following raw materials in parts by weight: 60-80 parts by weight of high-density polyethylene, 20-35 parts by weight of polyphenylene ether, 10-20 parts by weight of ethylene propylene diene rubber, 3-8 parts by weight of polyurethane prepolymer, 2-4 parts by weight of maleic anhydride grafted polyethylene, 0.5-1.5 parts by weight of 4,5-diamino-2-thiouracil, 5-12 parts by weight of silicon-based microcapsule coated basalt particles, 0.5-2 parts by weight of antioxidant, 0.1-1 parts by weight of light stabilizer and 1.5-2.5 parts by weight of glyceryl stearate.

2. The PE pipe according to claim 1, characterized in that: The method for preparing silicon-based microcapsules coated with basalt particles comprises the following steps: (1) Evenly mix tetraethyl orthosilicate, an organic solvent, a silane coupling agent and water, adjust the pH to 8-10, raise the temperature to 40-60°C, and react for 4-8 hours to obtain a sol; (2) immersing the basalt particles in the sol, mixing them evenly, heating them to 40-80°C, reacting them for 12-24 hours, cooling them, separating the solid and the liquid, drying them, and sintering them to obtain silicon-based microcapsule-coated basalt particles; The mass ratio of the tetraethyl orthosilicate, the organic solvent, the silane coupling agent, the water and the basalt particles is 1:(3-6):(0.02-0.05):(1.5-2.5):(2-5).

3. The PE pipe according to claim 2, characterized in that: The antioxidant is at least one of antioxidant 1010 and antioxidant 168.

4. The PE pipe according to claim 1, characterized in that: The PE tube also includes 1.5 to 4.5 parts by mass of modified konjac polysaccharide.

5. The PE pipe according to claim 4, characterized in that: The preparation method of the modified konjac polysaccharide comprises the following steps: After konjac polysaccharide and solvent are uniformly mixed, stearic acid and p-toluenesulfonic acid are added, the temperature is raised to 80-120°C, the reaction is performed for 6-12 hours, the temperature is lowered to room temperature, the solid-liquid separation is performed, and the modified konjac polysaccharide is obtained; The mass ratio of the konjac polysaccharide to stearic acid is 1:(3-5).

6. The PE pipe according to claim 5, characterized in that: The dosage of the p-toluenesulfonic acid is 0.8% to 2% of the total mass of konjac polysaccharide and stearic acid.

7. The PE pipe according to claim 1, characterized in that: The PE tube also includes 8 to 10 parts by mass of polyisobutylene.

8. A method for preparing a PE pipe according to any one of claims 1 to 7, characterized in that: The steps include: S1: adding high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer, and mixing them evenly to obtain a premix; S2: The premix is ​​transferred to an internal mixer, heated to 140-160°C, mixed for 10-15 minutes, and then 4,5-diamino-2-thiouracil, silicon-based microcapsule-coated basalt particles, antioxidant, light stabilizer and stearyl glycerol are added, and the mixture is further mixed for 10-15 minutes, and cooled to obtain an extrudate; S3: The extrudate is conveyed to the feed port of the twin-screw extruder, extruded, sized, pulled, cooled and shaped, and cut to obtain a PE pipe.

9. The method for preparing a PE pipe according to claim 8, characterized in that: In step S2, after adding 4,5-diamino-2-thiouracil, the method further comprises adding modified konjac polysaccharide.

10. The method for preparing a PE pipe according to claim 8, characterized in that: In step S1, when adding EPDM rubber, the step of adding polyisobutylene is also included.

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