A PE pipe and its preparation method

Abstract

This application relates to the technical field of PE pipe processing, and specifically discloses a PE pipe and a preparation method thereof. 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. The PE pipe prepared by this application has good mechanical properties and anti-aging properties.

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 its preparation method. Background Art

[0002] PE pipe, namely polyethylene pipe, as a common plastic pipe material, is mainly used in fields such as water supply, drainage, and gas transmission. However, it has some performance drawbacks. In terms of mechanical properties, the strength of PE pipe is limited. Especially when facing large pressure or impact force, it is prone to deformation or even rupture. In terms of high-temperature resistance, PE pipe is extremely prone to deformation and softening under high-temperature environment, which not only seriously shortens its service life, but also poses a great threat to the safety performance during use. At the same time, during long-term use, PE pipe is affected by various factors such as ultraviolet rays, oxygen, and heat, and the aging problem is relatively prominent, resulting in continuous decline of pipe performance. In addition, the pressure resistance of PE pipe is relatively low, and it is difficult to meet some special use scenarios with high pressure and large flow rate. Under high-pressure environment, PE pipe is 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 its special microstructure and surface properties, it is difficult to ensure its 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. When the weak areas are stressed, they are not only prone to deformation, but also with the continuous deformation and stress concentration, microcracks will gradually appear 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 and compressive properties of PE pipe, this application provides a PE pipe and its preparation method.

[0006] In the first aspect, this application provides a PE pipe, adopting the following technical solution:

[0007] 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.

[0008] 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. The synergistic effect of this bonding and physical winding effectively shortens the interfacial distance between each component, 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 suppressing the phase separation phenomenon, thereby 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, enabling the basalt particles to share part of the external load acting on the pipe matrix, thus significantly improving the ring stiffness and overall strength of the pipe.

[0009] 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 generate π-π stacking interactions to assist in the formation of the quasi-supramolecular structure. This structure can play a role of "molecular bridge" 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 each polymer more compact, and thus comprehensively improving the mechanical properties of the entire material, such as tensile strength and tear strength, and significantly enhancing the tensile and tear resistance of the PE pipe.

[0010] 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 generates 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.

[0011] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

[0012] Preferably, the light stabilizer is 2-(2H-benzotriazol-2-yl)-4,6-ditert-amylphenol.

[0013] Preferably, the method for preparing the silicon-based microcapsule-coated basalt particles comprises the following steps:

[0014] (1) Mix tetraethyl orthosilicate, an organic solvent, a silane coupling agent and water uniformly, adjust the pH to 8-10, raise the temperature to 40-60 °C, and react for 4-8 h to obtain a sol;

[0015] (2) Immerse the basalt particles in the sol, mix uniformly, raise the temperature to 40-80 °C, react for 12-24 h, cool down, separate the solid and liquid, dry, and sinter to obtain the silicon-based microcapsule-coated basalt particles;

[0016] 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).

[0017] 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 being originally hydrophilic to having 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 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 substances. These interfacial interactions significantly enhance the compatibility between basalt and polyethylene, making the two no longer a simple physical mixture, but forming a composite system with mutual interactions at the molecular level. This molecular-level interaction effectively inhibits the agglomeration and sedimentation of basalt particles in the polyethylene matrix, keeping them in a relatively stable and uniform distribution state in the polyethylene matrix.

[0018] Preferably, the PE pipe further comprises 1.5-4.5 parts by mass of modified konjac polysaccharide.

[0019] Preferably, the method for preparing the modified konjac polysaccharide comprises the following steps:

[0020] After mixing 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 solid from liquid, and dry to obtain modified konjac polysaccharide;

[0021] The mass ratio of the konjac polysaccharide to the stearic acid is 1:(3~5).

[0022] Preferably, the solvent is N,N-dimethylformamide, and the mass ratio of the konjac polysaccharide to N,N-dimethylformamide is 1:(5~7).

[0023] Preferably, the dosage of the p-toluenesulfonic acid is 0.8%~2% of the total mass of the konjac polysaccharide and the stearic acid.

[0024] In this technical solution, by adding the modified konjac polysaccharide into the PE pipe system, the polysaccharide chain in its molecule can play a role similar to a "molecular bridge" in the PE pipe substrate, not only making the binding between polymer chains closer, 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 binding between components and enhance the overall structural stability and mechanical properties.

[0025] Preferably, the PE pipe further comprises 8~10 parts by mass of polyisobutylene.

[0026] 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 chain can play a filling role in the gaps between the molecular chains of polymers such as high-density polyethylene, not only enhancing the binding strength between different polymers, but also enhancing the interaction between polymer molecular chains, restricting the movement of molecular chains to a certain extent, thereby improving the anti-aging performance. However, the flexibility of polyisobutylene itself plays a compensating role, so overall the material will not become brittle due to increased rigidity, but can still maintain good ductility to a certain extent, making the elongation at break remain stable or increase within a certain range.

[0027] Preferably, the PE pipe further comprises 6~8 parts by mass of polybutylene adipate.

[0028] In this technical solution, when polybutylene adipate is added to the PE pipe, it can improve the flexibility and low-temperature resistance of the PE pipe, enabling it to still maintain good performance in cold environments and reducing the risk of brittle fracture.

[0029] In the second aspect, the present application provides a preparation method of the above-mentioned PE pipe, comprising the following steps:

[0030] 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.

[0031] S2: Transfer the premix to an internal mixer, heat up to 140 - 160 °C, mix for 10 - 15 min, then 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 an extruded material.

[0032] 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 a PE pipe.

[0033] 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 is 160 - 170 °C, zone 2 is 170 - 180 °C, zone 3 is 180 - 190 °C, and zone 4 is 190 - 200 °C.

[0034] Preferably, in step S2, after adding 4,5-diamino-2-thiouracil, it further includes the step of adding modified konjac polysaccharide.

[0035] Preferably, in step S1, when adding ethylene propylene diene monomer rubber, it further includes the step of adding polyisobutylene.

[0036] Preferably, in step S1, when adding ethylene propylene diene monomer rubber, it further includes the step of adding polybutylene adipate.

[0037] In summary, the present application has the following beneficial effects:

[0038] 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 rubber, 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, flexural strength, impact strength, etc., and at the same time improving the processing performance of the PE pipe substrate, making it more fluid and easier to form during processing such as extrusion molding, reducing the generation of defects.

[0039] 2. This application uses silicon-based microcapsules to coat 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, giving full play to their strengthening effect and improving the mechanical properties and stability of the PE pipe.

[0040] 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 polymer chains in the substrate bind more closely and further enhancing the mechanical properties of the PE pipe. Specific embodiments

[0041] The following further elaborates on this application with reference to examples.

[0042] Unless otherwise specified, the raw materials in the examples, preparation examples, and comparative examples of this application are all commercially available.

[0043] In the following examples, preparation examples, and comparative examples:

[0044] The basalt particles are processed through the following steps before use:

[0045] After the basalt particles are washed, dried, and ground, first pass through a 500-mesh sieve and take the undersize for standby;

[0046] The polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene ether), and its molecular weight distribution is 30,000 - 50,000;

[0047] The polyurethane prepolymer is a polyether-type MDI-capped polyurethane prepolymer (referred to as polyurethane prepolymer), with an -NCO content of about 8% - 10% and a molecular weight distribution of about 2000;

[0048] The light stabilizer is 2-(2H-benzotriazol-2-yl)-4,6-ditert-amylphenol (referred to as UV-328).

[0049] Preparation Examples 1 - 3 Silicon-based Microcapsule-coated Basalt Particles

[0050] Preparation Example 1

[0051] This preparation example provides a preparation method for silicon-based microcapsule-coated basalt particles, including the following steps:

[0052] (1) Add 300 g of absolute ethanol into the 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 the range of 8 - 8.5 with 5% potassium hydroxide by mass fraction. Heat up to 40 °C and react for 8 h to obtain a uniformly distributed sol;

[0053] (2) Slowly pour 200 g of basalt particles into the sol prepared above, stir and mix evenly, heat up 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 up to 600 °C at a rate of 4 °C / min, sinter for 3 h, cool to room temperature with the furnace, and slightly grind and disperse for standby.

[0054] Preparation Example 2

[0055] This preparation example provides a preparation method of silicon-based microcapsule-coated basalt particles, which includes the following steps:

[0056] (1) Add 600 g of absolute ethanol into the 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 uniformly distributed sol;

[0057] (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.

[0058] Preparation Example 3

[0059] This preparation example provides a preparation method of silicon-based microcapsule-coated basalt particles, which includes the following steps:

[0060] (1) Add 450 g of absolute ethanol into the 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 uniformly distributed sol;

[0061] (2) Slowly pour 300 g of basalt particles into the above-prepared sol, 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, and dry at 80 °C until constant weight. 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.

[0062] Preparation Examples 4 - 6 of Modified Konjac Polysaccharide

[0063] Preparation Example 4

[0064] This preparation example provides a method for preparing modified konjac polysaccharide, which includes the following steps:

[0065] Add 500 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 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 precipitate is formed, filter, wash twice with absolute ethanol, transfer to a drying oven, and dry at 80 °C until constant weight. Slightly grind and fractionate to obtain the modified konjac polysaccharide.

[0066] Take 5 g of the modified konjac polysaccharide and put it into 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 a 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%.

[0067] Preparation Example 5

[0068] This preparation example provides a method for preparing modified konjac polysaccharide, which includes the following steps:

[0069] 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 twice with absolute ethanol, transfer to a drying oven, and dry at 80 °C until constant weight. Slightly grind and fractionate to obtain the modified konjac polysaccharide.

[0070] Take 5 g of the modified konjac polysaccharide and put it into 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 a 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%.

[0071] Preparation Example 6

[0072] This preparation example provides a method for preparing modified konjac polysaccharide, which includes the following steps:

[0073] Add 600 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 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 down to room temperature, add anhydrous ethanol until no precipitation occurs, filter, wash twice with anhydrous ethanol, transfer to a drying oven, and dry to constant weight at 80 °C, and slightly grind to obtain modified konjac polysaccharide.

[0074] Take 5 g of modified konjac polysaccharide and put it into 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, and replace 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%.

[0075] Example 1

[0076] This example 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.

[0077] Among them, the silicon-based microcapsule coated basalt particles are from Preparation Example 1; the antioxidant is antioxidant 1010.

[0078] This example also provides a method for preparing the above-mentioned PE pipe, which includes the following steps:

[0079] 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, and mix at a speed of 800 r / min for 8 min to obtain a premix;

[0080] 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 quality, keep at 140 °C, and continue to mix for 10 min, and naturally cool down to room temperature to obtain an extrusion material;

[0081] S3: Feed the extruded material to the feed inlet of the twin-screw extruder. After installing the corresponding die, start the twin-screw extruder.

[0082] Set the screw speed to 100 r / min and adjust the temperatures of each zone of the extruder: Zone 1 at 160 °C, Zone 2 at 170 °C, Zone 3 at 180 °C, and Zone 4 at 190 °C. After extrusion, immediately enter the sizing device. The sized pipe is pulled by the traction equipment at a speed of 1 m / min into the cooling water tank, where it is rapidly cooled and shaped. The cooling water temperature is controlled within the range of 15 - 25 °C. Then, through the cutting equipment, it is cut according to the predetermined length to obtain the finished PE pipe.

[0083] Example 2

[0084] This example provides a PE pipe made from the following parts by mass of raw materials: 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.

[0085] 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.

[0086] This example also provides a method for preparing the above PE pipe, including the following steps:

[0087] 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 mass, and mix at a speed of 800 r / min for 12 min to obtain a premix.

[0088] S2: Transfer the premix to the internal mixer, heat it to 160 °C, mix for 15 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, maintain at 160 °C, continue to mix for 15 min, and naturally cool to room temperature to obtain the extruded material.

[0089] S3: Feed the extruded material to the feed inlet of the twin-screw extruder. After installing the corresponding die, start the twin-screw extruder.

[0090] 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, it immediately enters the sizing device. The sized pipe is pulled by the traction equipment at a speed of 2 m / min into the cooling water tank, where it is rapidly cooled and shaped. 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.

[0091] Example 3

[0092] 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, and 20 g of glyceryl stearate.

[0093] 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.

[0094] This example also provides a method for preparing the above PE pipe, which includes the following steps:

[0095] 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 masses, and mix at a speed of 800 r / min for 10 min to obtain a premix.

[0096] S2: Transfer the premix to an internal mixer, heat it to 150 °C, mix for 13 min, then add 4,5-diamino-2-thiouracil, silicon-based microcapsule-coated basalt particles, antioxidant, light stabilizer, and glyceryl stearate according to the above masses, keep it at 150 °C, and continue to mix for 13 min. Then, cool it naturally to room temperature to obtain an extrusion material.

[0097] S3: Feed the extrusion material to the feed port of a twin-screw extruder. After installing the corresponding die, start the twin-screw extruder.

[0098] 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, it immediately enters 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, where it is rapidly cooled and shaped. 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.

[0099] Example 4

[0100] 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, and 15 g of modified konjac polysaccharide.

[0101] 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.

[0102] This example also provides a method for preparing the above-mentioned PE pipe, which includes the following steps:

[0103] 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 masses, and mix at a speed of 800 r / min for 10 min to obtain a premix.

[0104] 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.

[0105] S3: Transport the extrusion material to the feed inlet of a twin-screw extruder, install the corresponding die, start the twin-screw extruder,

[0106] 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 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.

[0107] Example 5

[0108] The difference between this example and Example 4 is that:

[0109] The dosage of the modified konjac polysaccharide is 30 g; the modified konjac polysaccharide is from Preparation Example 5.

[0110] Others are the same as in Example 4.

[0111] Example 6

[0112] 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, and 80 g of polyisobutylene.

[0113] 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.

[0114] This example also provides a preparation method of the above-mentioned PE pipe, which includes the following steps:

[0115] S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, 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.

[0116] 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.

[0117] S3: Transport the extrusion material to the feed inlet of a twin-screw extruder. After installing the corresponding die, start the twin-screw extruder.

[0118] 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 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.

[0119] Example 7

[0120] The difference between this example and Example 6 is that:

[0121] The dosage of polyisobutylene is 100 g; the modified konjac polysaccharide is from Preparation Example 5.

[0122] Others are the same as in Example 6.

[0123] Example 8

[0124] 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 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 polyisobutylene, and 60 g of polybutylene adipate.

[0125] 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.

[0126] This example also provides a preparation method of the above PE pipe, which includes the following steps:

[0127] S1: Add high-density polyethylene, polyphenylene ether, ethylene propylene diene monomer rubber, polyisobutylene, polybutylene adipate, polyurethane prepolymer, and maleic anhydride grafted polyethylene into a high-speed mixer according to the above quality, and mix at a speed of 800 r / min for 12 min to obtain a premix.

[0128] S2: Transfer the premix to an internal mixer, heat it 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 quality, keep it at 150 °C, continue to mix for 13 min, and naturally cool to room temperature to obtain an extruded material.

[0129] S3: Transport the extruded material to the feed inlet of a twin-screw extruder, install the corresponding die, start the twin-screw extruder,

[0130] 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 a finished PE pipe.

[0131] Example 9

[0132] The difference between this example and Example 8 is that:

[0133] The dosage of polybutylene adipate is 80 g.

[0134] Others are the same as in Example 8.

[0135] Comparative Example 1

[0136] The difference between this comparative example and Example 1 is that:

[0137] Basalt particles of equal mass were directly added. Before use, the basalt particles were subjected to the following pretreatment steps:

[0138] After the basalt particles were washed, dried, and ground, they were first passed through a 500-mesh sieve, and the undersize was taken for standby.

[0139] Others are the same as in Example 1.

[0140] Comparative Example 2

[0141] The difference between this comparative example and Example 1 is that:

[0142] Basalt particles of equal mass were directly added. Before use, the basalt particles were subjected to the following pretreatment steps:

[0143] After the basalt particles were washed, dried to constant weight, and ground, 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.

[0144] Among them, the mass ratio of the silane coupling agent solution to the preliminarily treated basalt particles is 5:1.

[0145] The silane coupling agent solution includes silane coupling agent KH550, ethanol, and water. The mass fraction of silane coupling agent KH550 is 2%, the mass fraction of ethanol is 78%, and the rest is deionized water.

[0146] Comparative Example 3

[0147] The difference between this comparative example and Example 1 is that:

[0148] 4,5-Diamino-2-thiouracil was not added.

[0149] Others are the same as in Example 1.

[0150] Comparative Example 4

[0151] The polyurethane prepolymer was not added, and the amount of maleic anhydride grafted polyethylene was adjusted to 50 g.

[0152] Comparative Example 5

[0153] The difference between this comparative example and Example 1 is that:

[0154] No polyphenylene ether was added.

[0155] Other conditions are the same as in Example 1.

[0156] Performance detection test

[0157] 1. Performance detection in the first stage

[0158] Mechanical property test:

[0159] (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. 5 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 this group of specimens. The test results are shown in Table 1.

[0160] (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. 5 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 this group of specimens. The test results are shown in Table 1.

[0161] (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. 10 parallel specimens were prepared for each group. A falling weight impact testing machine was used, with a falling weight of 12 kg and a falling height of the weight within the range of 2 m±0.02 m. The weight was allowed to fall freely to 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.

[0162] Aging resistance 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 box to 100°C, the aging box was started, and its internal temperature was allowed to rise uniformly and stabilize 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 box. The test specimens were placed in the aging box for experiments. After 72 hours, 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 hours. Then, an electronic universal testing machine was used to test the tensile strength of the aged specimens. 5 parallel specimens of each aged specimen 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.

[0163] Table 1 Performance test data of finished PE pipes in Examples 1-9 and Comparative Examples 1-5

[0164]

[0165] 2. Performance test in the second stage

[0166] Low temperature resistance test: According to GB / T3512-2001, the finished PE pipes in Examples 5-9 were respectively cut into dumbbell-shaped specimens. After the temperature of the low temperature aging chamber was set at -20°C and 0°C respectively, the low temperature aging chamber was started, and its internal temperature was uniformly decreased and stabilized within the target temperature range of -20±2°C and 0°C±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 chamber. The test specimens were placed in the low temperature aging chamber for experiments. After 72 hours, the specimens were taken out, and the specimens after low temperature aging were transferred to an environment with a temperature of 23±2°C and a relative humidity of 50±5% for conditioning for 48 hours. Then, the low temperature impact resistance was tested. 10 parallel specimens were prepared in each group, and the impact results of the specimens (the number of ruptures was counted) were observed and recorded. The test results are shown in Table 2.

[0167] Table 2 Impact resistance test data of finished PE pipes in Examples 5-9

[0168]

[0169] It can be seen from the test data in Table 1 that

[0170] From Example 1 and Comparative Examples 1-5, 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 closely, 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 bonding 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 construct 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.

[0171] As can be seen from Examples 1 to 9, with the addition of modified konjac polysaccharide, polyisobutylene, and poly(butylene adipate), both the tensile strength and the elongation at break show a gradually increasing trend. The 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 and thus increasing the tensile strength. Polyisobutylene can penetrate between the molecular chains of other polymers, not only endowing the PE pipe with good flexibility but also connecting different polymer molecules, to a certain extent increasing the tensile strength. Poly(butylene adipate) can form certain interactions with other molecules through ester groups, improving the overall structural stability of the material and further enhancing the tensile strength. In addition, the addition of polyisobutylene and poly(butylene adipate) also enhances the impact resistance of the PE pipe at -20°C.

[0172] 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 without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A PE pipe, characterized in that: The invention comprises 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, 1.5-4.5 parts by weight of modified konjac polysaccharide and 1.5-2.5 parts by weight of glyceryl stearate; 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); 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).

2. The PE pipe according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1010 and antioxidant 168.

3. The PE pipe according to claim 1, 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.

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

5. A method for preparing a PE pipe as claimed in any one of claims 1 to 4, 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: transferring the premix to an internal mixer, heating to 140-160° C., mixing for 10-15 minutes, adding 4,5-diamino-2-thiouracil, silicon-based microcapsule-coated basalt particles, antioxidants, light stabilizers and stearyl glycerol, continuing to mix for 10-15 minutes, cooling, and obtaining an extrudate, wherein after adding 4,5-diamino-2-thiouracil, a step of adding modified konjac polysaccharide is also included; 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.

6. The method for preparing a PE pipe according to claim 5, characterized in that: In step S1, when adding EPDM rubber, the step of adding polyisobutylene is also included.

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