Low-temperature-resistant creep-resistant PE water supply pipe and preparation process thereof

Abstract

The invention discloses a low-temperature-resistant creep-resistant PE water supply pipe and a preparation process thereof, and relates to the technical field of PE pipes. The PE water supply pipe comprises the following components in parts by weight: 60-80 parts of high-density polyethylene, 5-7 parts of ultra-high molecular weight polyethylene, 0.5-2 parts of organic illite-montmorillonite soil, 2-5 parts of a polyolefin elastomer, 2-5 parts of a cycloolefin copolymer, 1-2 parts of a compatilizer, 0.1-0.5 part of an antioxidant and 0.1-0.5 part of an antibacterial agent. By introducing the halloysite nanotube-loaded cuprous oxide hybrid material, an efficient and lasting antibacterial function is realized, application scenarios, such as hospitals and direct drinking water systems, having strict requirements on water quality are met, the problems of quick release and short validity period of an antibacterial agent are solved, and the comprehensive performance of the PE water supply pipe is improved.

Description

Technical Field

[0001] This invention relates to the field of PE pipe technology, specifically to a low-temperature resistant and creep-resistant PE water supply pipe and its manufacturing process. Background Technology

[0002] PE water supply pipes, as an important material in modern water supply systems, are made from polyethylene resin and feature corrosion resistance and good flexibility. PE water supply pipes are lightweight, easy to transport and install, significantly shortening the construction cycle and reducing labor costs. They are widely used in municipal water supply, building water supply, farmland irrigation, and many other fields.

[0003] With increasing demands for water quality safety, traditional PE pipes, despite their advantages of corrosion resistance and ease of construction, are prone to bacterial growth and biofilm formation during long-term use, leading to secondary water pollution. This problem is particularly pronounced in rural water supply systems and aging pipe networks.

[0004] Patent CN110698747B discloses a creep-resistant and impact-resistant PE pipe and its production method. The above patent achieves a smooth PE pipe surface, low end warping, and improves the weather resistance, creep resistance, and impact resistance of the PE pipe.

[0005] The aforementioned patents have solved the problems of poor temperature creep resistance, easy catalysis and poor weather resistance of polyethylene (PE) pipes, large shrinkage during molding, and easy pipe aging. However, there is still room for improvement in terms of the pipe's long-lasting antibacterial properties. This application achieves efficient and long-lasting antibacterial function and solves the problems of rapid release and short shelf life of antibacterial agents.

[0006] Therefore, this application proposes a low-temperature resistant and creep-resistant PE water supply pipe with efficient and long-lasting antibacterial function and its manufacturing process. Summary of the Invention

[0007] The purpose of this invention is to provide a low-temperature resistant and creep-resistant PE water supply pipe and its manufacturing process, so as to solve the technical problems of rapid release and short effective period of antibacterial agents mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a low-temperature resistant and creep-resistant PE water supply pipe, wherein the PE water supply pipe comprises, by weight: 60-80 parts of high-density polyethylene, 5-7 parts of ultra-high molecular weight polyethylene, 0.5-2 parts of organic imidium monoxide, 2-5 parts of polyolefin elastomer, 2-5 parts of cyclic olefin copolymer, 1-2 parts of compatibilizer, 0.1-0.5 parts of antioxidant, and 0.1-0.5 parts of antibacterial agent, wherein the compatibilizer is polyethylene grafted with maleic anhydride, and the antibacterial agent is halloysite nanotube-supported cuprous oxide hybrid material.

[0009] Preferably, the raw materials for grafting maleic anhydride onto polyethylene include: high-density polyethylene, maleic anhydride, dicumyl peroxide, antioxidant 1010, and liquid paraffin, with a mass ratio of 100:0.5:0.1:0.1:1.

[0010] Preferably, the preparation method of the halloysite nanotube-supported cuprous oxide hybrid material includes the following steps: Halloysite nanotubes were poured into deionized water, ultrasonically stirred for 30 min, sodium hydroxide solution was added, stirred at room temperature for 12 h, centrifuged, washed with deionized water until neutral, and dried at 80℃ to obtain pretreated halloysite nanotubes. The pretreated halloysite nanotubes were poured into deionized water, heated to 80°C, and hexadecyltrimethylammonium bromide was added. The mixture was stirred at a constant temperature for 2 hours, and copper sulfate pentahydrate solution was slowly added. Sodium hydroxide solution and ascorbic acid solution were added dropwise under stirring conditions. The mixture was cooled to room temperature, centrifuged, washed, and dried to obtain halloysite nanotube-supported cuprous oxide hybrid material.

[0011] Preferably, the method for preparing the polyethylene grafted with maleic anhydride includes the following steps: Liquid paraffin and high-density polyethylene granules were stirred in a high-speed mixer for 1 minute. Maleic anhydride, dicumyl peroxide, and antioxidant 1010 were added and stirred for 5 minutes. The mixture was then extruded and granulated using a twin-screw extruder to obtain polyethylene grafted with maleic anhydride.

[0012] Preferably, the method for preparing the organic imidacloprid includes the following steps: Immonite was poured into deionized water, stirred and allowed to stand for 24 hours. Hexadecyltrimethylammonium bromide was added, and the pH was adjusted to 3 using glacial acetic acid. The mixture was stirred at 75°C for 2 hours. Silane coupling agent KH-570 dissolved in anhydrous ethanol was added, and the mixture was stirred at 75°C for 4 hours. After centrifugation, washing, and drying, organic immonite was obtained.

[0013] Preferably, the polyolefin elastomer is selected with a molecular weight of 7.95 × 10⁻⁶. 4 Low molecular weight polyolefin elastomers.

[0014] Preferably, the cyclic olefin copolymer is a low melt index cyclic olefin copolymer with a melt index range of 0.8-1.2 g / 10 min.

[0015] Preferably, the antioxidant is one or a combination of antioxidant 1010 and antioxidant 168.

[0016] Preferably, the preparation process includes the following steps: S1. Weigh out high-density polyethylene, ultra-high molecular weight polyethylene, organic imidium monoxide, polyolefin elastomer, cyclic olefin copolymer, compatibilizer, antioxidant, and antibacterial agent, add them to a high-speed mixer and premix them evenly. Then, use a twin-screw extruder to granulate the mixture to obtain composite granules. S2. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0017] Preferably, the twin-screw extruder temperatures in step S1 are: 150-170℃ in the feeding section, 180-200℃ in the melting section, 200-220℃ in the mixing section, and 210-230℃ in the die head. In step S2, the temperatures of the single screw extruder are as follows: feeding section 150-170℃, compression section 180-200℃, melt conveying section 180-200℃, and mandrel temperature of the rotary shearing device 190-200℃.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves efficient and long-lasting antibacterial function by introducing halloysite nanotubes loaded with cuprous oxide hybrid materials, meeting the application scenarios with stringent water quality requirements such as hospitals and direct drinking water systems, solving the problems of rapid release and short effective period of antibacterial agents, and improving the overall performance of PE water supply pipes; 2. By introducing maleic anhydride grafted onto polyethylene, this invention achieves good compatibility among the components, solves the problems of poor dispersion and weak interfacial bonding of inorganic fillers in the polyethylene matrix, improves the mechanical properties of PE water supply pipes, and enhances processing stability. 3. By introducing organic imidized imidized clay, this invention achieves organic composite of inorganic filler and polyethylene matrix, which improves the strength and modulus of PE water supply pipe, achieves a balance between enhanced rigidity and toughness of PE water supply pipe, and improves the overall performance of PE water supply pipe. 4. This invention achieves toughening modification of the rigid matrix by introducing polyolefin elastomers and cyclic olefin copolymers, solving the problem of difficulty in achieving both high strength and high toughness, improving the impact strength and toughness of PE water supply pipes, and improving processing fluidity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the PE water supply pipe manufacturing process of the present invention; Figure 2 This is a schematic diagram of the halloysite nanotube pretreatment process of the present invention; Figure 3 This is a schematic diagram of the antibacterial agent preparation process of the present invention; Figure 4 This is a schematic diagram of the polyethylene grafting maleic anhydride preparation process of the present invention. Figure 5 This is a schematic diagram of the imidacloprid modification process of the present invention; Figure 6 This is a schematic diagram of the antioxidant of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1, please refer to Figure 1 , Figure 2 , Figure 3 and Figure 6 A low-temperature resistant and creep-resistant PE water supply pipe, the manufacturing process of which includes the following steps: Halloysite nanotubes were poured into deionized water and ultrasonically stirred for 30 min. Sodium hydroxide solution was added, and the mixture was stirred at room temperature for 12 h. After centrifugation, the nanotubes were washed with deionized water until neutral and dried at 80 °C to obtain pretreated halloysite nanotubes. The pretreated halloysite nanotubes were then poured into deionized water, heated to 80 °C, and hexadecyltrimethylammonium bromide was added. The mixture was stirred at a constant temperature for 2 h, and copper sulfate pentahydrate solution was slowly added. Sodium hydroxide solution and ascorbic acid solution were added dropwise under stirring conditions. The mixture was cooled to room temperature, centrifuged, washed, and dried to obtain halloysite nanotube-supported cuprous oxide hybrid material. 80 parts of high-density polyethylene, 7 parts of ultra-high molecular weight polyethylene, 2 parts of organic imidium oxide, 5 parts of polyolefin elastomer, 5 parts of cyclic olefin copolymer, 2 parts of polyethylene grafted maleic anhydride, 0.5 parts of antioxidant 1010, and 0.5 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0022] Furthermore, halloysite nanotubes, as one-dimensional nanomaterials, possess a high specific surface area and a unique tubular structure, thus providing an ideal carrier for loading cuprous oxide. Cuprous oxide, as an antibacterial material, exhibits inhibitory and inactivating effects against various bacteria. By loading cuprous oxide onto halloysite nanotubes and modifying it with hexadecyltrimethylammonium bromide as a surfactant, the aggregation of cuprous oxide can be inhibited, thereby preparing an antibacterial agent with a halloysite nanotube-loaded cuprous oxide hybrid material. The tubular structure of the halloysite nanotubes and the modification effect of the surfactant can improve the stability of the hybrid material, reduce the rapid release of copper ions, achieve long-term sustained release, and prolong the antibacterial effect. The tube wall of the halloysite nanotubes also enhances the resistance of the internal cuprous oxide... Copper provides some protection, slowing down the oxidation and deactivation of cuprous oxide. The hybrid material has a positively charged surface, which can generate strong electrostatic adsorption with the negatively charged bacterial cell membrane, destroying the integrity of the bacterial cell membrane and leading to bacterial death. The hybrid material can slowly release Cu+ ions in a humid environment. After Cu+ penetrates the cell membrane, it can interfere with the activity of various enzymes, disrupting the energy metabolism and normal physiological functions of bacteria. When PE water supply pipes are in operation, the humid environment inside the pipe is a breeding ground for microorganisms and the formation of biofilms. Biofilms not only pollute water quality but may also exacerbate pipe corrosion. The introduction of hybrid materials enables PE water supply pipes to actively and continuously kill or inhibit microorganisms in contact with the pipe wall, fundamentally preventing the formation of biofilms and ensuring the safety and hygiene of the water supply.

[0023] Example 2, please refer to Figure 1 , Figure 4 and Figure 6 A low-temperature resistant and creep-resistant PE water supply pipe, the manufacturing process of which includes the following steps: Liquid paraffin and high-density polyethylene granules were stirred in a high-speed mixer for 1 minute. Maleic anhydride, dicumyl peroxide, and antioxidant 1010 were added and stirred for 5 minutes. The mixture was then extruded and granulated using a twin-screw extruder to obtain polyethylene grafted with maleic anhydride. The mass ratio of high-density polyethylene, maleic anhydride, dicumyl peroxide, antioxidant 1010, and liquid paraffin was 100:0.5:0.1:0.1:1. 75 parts of high-density polyethylene, 7 parts of ultra-high molecular weight polyethylene, 2 parts of organic imidium oxide, 4 parts of polyolefin elastomer, 4 parts of cyclic olefin copolymer, 2 parts of polyethylene grafted maleic anhydride, 0.4 parts of antioxidant 1010, and 0.4 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0024] Furthermore, polyethylene is a non-polar polymer, while organic imidium oxide and antibacterial agents are both highly polar inorganic nanomaterials. If directly blended, due to the huge difference in surface energy and lack of chemical bonding, the inorganic nanoparticles will severely aggregate due to strong van der Waals forces, forming stress defect points. The interface between the nanoparticles and the polyethylene matrix is ​​weak, which will cause the aggregates to become stress concentration points, significantly accelerating the damage of water supply pipes under long-term hydrostatic pressure. Imidium oxide cannot be effectively exfoliated into nanosheets, and its effect of enhancing creep resistance and barrier properties is greatly reduced. Introducing maleic anhydride grafted onto polyethylene solves the problem of multiphase interface incompatibility through a dual mechanism of similar compatibility and chemical bonding. The molecular structure of polyethylene grafted with maleic anhydride comprises a nonpolar polyethylene backbone and polar maleic anhydride groups. The polyethylene-grafted maleic anhydride backbone and the molecular chains of the matrix polyethylene are physically bonded through intermolecular forces, dissolving and entangled with each other. Under high-temperature melt blending conditions, the maleic anhydride functional groups of the polyethylene-grafted maleic anhydride side chains can chemically react with functional groups on the surface of imidium montmorillonite and antibacterial agents, forming covalent bonds. The synergistic effect of the physical entanglement between the polyethylene chain segments and the matrix, and the chemical bonding between the maleic anhydride functional groups and the inorganic nanofillers, constructs a molecular bridge between the inorganic nanofillers and the matrix. Through the interfacial compatibility of polyethylene-grafted maleic anhydride, organication is achieved. The uniform dispersion of imidium monoxide and antibacterial agents in the polyethylene matrix ensures that the halloysite nanotube-loaded cuprous oxide hybrid material particles can fully expose their surfaces, allowing them to contact bacteria in the water flow and exert their antibacterial activity. This avoids the aggregation of the hybrid material, which would prevent it from contacting bacteria and reduce the antibacterial efficiency. Under good compatibility and shear force, the layered structure of the organic imidium monoxide is exfoliated into nanosheets, effectively extending the movement path of the molecular chains and significantly improving the material's creep resistance and barrier properties. By strengthening the interfacial bonding, the grafting of maleic anhydride onto polyethylene can significantly improve the tensile strength and modulus of PE water supply pipes, greatly improving their creep resistance.

[0025] Example 3, please refer to Figure 1 , Figure 5 and Figure 6 A low-temperature resistant and creep-resistant PE water supply pipe, the manufacturing process of which includes the following steps: Immonite was poured into deionized water, stirred and allowed to stand for 24 hours. Hexadecyltrimethylammonium bromide was added, and the pH was adjusted to 3 using glacial acetic acid. The mixture was stirred at 75°C for 2 hours. Silane coupling agent KH-570 dissolved in anhydrous ethanol was added, and the mixture was stirred at 75°C for 4 hours. After centrifugation, washing and drying, organic immonite was obtained. 70 parts of high-density polyethylene, 6 parts of ultra-high molecular weight polyethylene, 1.5 parts of organic imidium oxide, 4 parts of polyolefin elastomer, 4 parts of cyclic olefin copolymer, 2 parts of polyethylene grafted maleic anhydride, 0.4 parts of antioxidant 1010, and 0.4 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0026] Furthermore, hexadecyltrimethylammonium bromide is inserted into the interlayer of imidium montmorillonite via ion exchange, expanding the interlayer spacing and introducing hydrophobic alkyl chains. Through grafting with a silane coupling agent, the surface of the imidium montmorillonite is hydrophobicized. The organically modified imidium montmorillonite has a layered silicate structure, and its sheet surface is organically modified from hydrophilic to hydrophobic, improving its compatibility with the polyethylene matrix. During melt blending, the organically modified imidium montmorillonite sheets can be uniformly dispersed between the polyethylene molecular chains, forming a nanocomposite structure. The organically modified imidium montmorillonite sheet structure, through physical cross-linking points, can restrict the slippage and orientation rearrangement of the polyethylene molecular chains, thereby inhibiting… Plastic deformation under long-term stress, i.e. creep; organic imidium oxide nanosheets can still maintain rigidity at low temperatures, inhibiting brittle fracture caused by freezing of molecular chain segments, and synergistically improving the toughness of PE water supply pipes at low temperatures with polyolefin elastomers and cyclic olefin copolymers; the sheet structure of organic imidium oxide forms tortuous paths in the polyethylene matrix, thereby effectively blocking the diffusion of small substances such as oxygen and water molecules, while the antibacterial agent of cuprous oxide hybrid material loaded on Luoshi nanotubes needs to avoid oxidation failure caused by water or oxygen penetration. The barrier properties of organic imidium oxide can delay the degradation of antibacterial components and ensure antibacterial durability.

[0027] Example 4, please refer to Figure 1 A low-temperature resistant and creep-resistant PE water supply pipe, the manufacturing process of which includes the following steps: 65 parts of high-density polyethylene, 6 parts of ultra-high molecular weight polyethylene, 1.5 parts of organomodified imidol, 3 parts of polyolefin elastomer, 3 parts of cyclic olefin copolymer, 1 part of polyethylene grafted maleic anhydride, 0.3 parts of antioxidant 1010, and 0.3 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0028] Furthermore, as an elastomeric phase, polyolefin elastomers have flexible molecular chains. When subjected to external impact, they can absorb and disperse energy through their own elastic deformation, preventing crack propagation and effectively improving the brittleness of high-density polyethylene and ultra-high molecular weight polyethylene blends. Especially in low-temperature environments, they endow pipes with excellent flexibility and impact resistance, preventing low-temperature brittleness. Low molecular weight polyolefin elastomers have good compatibility with polyethylene and are easy to disperse uniformly in the matrix. The introduction of low molecular weight polyolefin elastomers reduces the overall melt viscosity of the blend system, enhances the fluidity during extrusion processing, and helps avoid the processing difficulties caused by the extremely high molecular weight of ultra-high molecular weight polyethylene. In addition, the addition of polyolefin elastomers can improve the gas barrier properties of the pipe, reduce gas permeation, and delay the oxidation or leakage of substances inside the pipe. Cyclic olefin copolymers possess rigid molecular chains and high heat distortion temperatures. The addition of cyclic olefin copolymers effectively inhibits the slippage and deformation of polyethylene molecular chains under long-term loads, significantly improving the creep resistance of pipes. The rigid structure of cyclic olefin copolymers increases the modulus and hardness of pipes, making them less prone to deformation under pressure and maintaining shape stability. Low melt index cyclic olefin copolymers have more compact molecular chains, effectively extending the permeation path of gases or liquids and enhancing the barrier properties of pipes. The rigid segments of cyclic olefin copolymers act as physical cross-linking points in the polyethylene matrix, restricting the movement of polyethylene molecular chains and suppressing amorphous regions. Regarding the creep behavior of chain segments, cyclic olefin copolymers can promote the formation of finer and more complete crystal structures in the polyethylene matrix, thereby improving the rigidity and thermal stability of the pipe. Furthermore, the longer molecular chains of low melt index cyclic olefin copolymers result in more complete entanglement with polyethylene, further inhibiting the relaxation and creep of molecular chains. The selection of low molecular weight polyolefin elastomers can significantly improve the low-temperature impact toughness of the pipe by elastic toughening and improving dispersibility while ensuring processing fluidity. On the other hand, the selection of low melt index cyclic olefin copolymers can utilize their rigid chain structure to enhance the rigidity, heat resistance, and creep resistance of the matrix, and optimize the crystal structure through heterogeneous nucleation.

[0029] Example 5, please refer to Figure 1 A low-temperature resistant and creep-resistant PE water supply pipe, the manufacturing process of which includes the following steps: 65 parts of high-density polyethylene, 5 parts of ultra-high molecular weight polyethylene, 0.5 parts of organomodified imidol, 2 parts of polyolefin elastomer, 2 parts of cyclic olefin copolymer, 1 part of polyethylene grafted maleic anhydride, 0.2 parts of antioxidant 1010, and 0.2 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0030] Furthermore, when the melt is subjected to circumferential shear force by a rotating mandrel within the mold cavity, the molecular chains are stretched and oriented. Long chains with sufficiently large molecular weights are less prone to relaxation and retraction under shearing, and can be straightened and aligned circumferentially, forming a shish structure similar to ridge fibers. This highly oriented shish structure along the flow direction serves as an ideal nucleation point, inducing the remaining molecular chains to grow epitaxially in a folded manner around it, forming periodic kebab plates, ultimately resulting in a highly anisotropic string crystal structure. Simultaneously or after shearing, rapid cooling of the mold preserves the string crystal structure formed in the melt, obtaining the desired circumferential reinforcement effect in the pipe, achieving a significant improvement in circumferential mechanical properties. In addition, due to its extremely high molecular weight and severe chain entanglement, ultra-high molecular weight polyethylene (UHMWPE) is difficult to integrate with high-density polyethylene (HDPE) in conventional processing, resulting in weak interfacial bonding. The strong shear field and high-temperature, high-pressure environment provided by the rotary shearing device effectively untangle the chain entanglement of UHMWPE, promoting better dissolution and dispersion of UHMWPE within the HDPE matrix, thereby forming a denser network structure.

[0031] Example 6, please refer to Figure 1 A low-temperature resistant and creep-resistant PE water supply pipe, the manufacturing process of which includes the following steps: 60 parts of high-density polyethylene, 5 parts of ultra-high molecular weight polyethylene, 0.5 parts of organomodified imidol, 2 parts of polyolefin elastomer, 2 parts of cyclic olefin copolymer, 1 part of polyethylene grafted maleic anhydride, 0.1 parts of antioxidant 1010, and 0.1 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0032] Comparative Example 1: 80 parts of high-density polyethylene, 7 parts of ultra-high molecular weight polyethylene, 2 parts of organomodified imidol, 5 parts of polyolefin elastomer, 5 parts of cyclic olefin copolymer, 2 parts of polyethylene grafted maleic anhydride, and 0.5 parts of antioxidant 1010 were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0033] Comparative Example 2: 80 parts of high-density polyethylene, 7 parts of ultra-high molecular weight polyethylene, 2 parts of unmodified imidium oxide, 5 parts of polyolefin elastomer, 5 parts of cyclic olefin copolymer, 2 parts of polyethylene grafted maleic anhydride, 0.5 parts of antioxidant 1010, and 0.5 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0034] Comparative Example 3: 80 parts of high-density polyethylene, 7 parts of ultra-high molecular weight polyethylene, 2 parts of organic imidium oxide, 5 parts of polyolefin elastomer, 5 parts of cyclic olefin copolymer, 0.5 parts of antioxidant 1010, and 0.5 parts of halloysite nanotube-supported cuprous oxide hybrid material were added to a high-speed mixer and premixed evenly. The mixture was then extruded and granulated using a twin-screw extruder to obtain composite granules. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt through a rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

[0035] Performance testing Test 1: Tensile property test. The finished products prepared in Examples 1-6 and Comparative Examples 1-3 were cut into ring-shaped samples with a thickness of about 8 mm. The circumferential tensile strength of the samples was tested by a universal tensile tester according to ISO 6259-3:1997 standard, with a tensile rate of 10 mm / min. Test 2 Impact performance test: The specimens prepared in Examples 1-6 and Comparative Examples 1-3 were cut into 80mm×10mm×4mm pieces and tested according to the standard GB / T 1043.1-2008. The instrument was a cantilever beam impact testing machine. Test 3 Antibacterial performance test: The samples prepared in Examples 1-6 and Comparative Examples 1-3 were cut into standard samples. According to GB / T 31402-2015 standard, the test strain was Escherichia coli ATCC 8739. The antibacterial rate was calculated as (AB) / A×100%, where A is the average number of viable bacteria in the control sample and B is the average number of viable bacteria in the sample.

[0036] Table 1. Test Results of Performance Testing

[0037] In summary, the performance tests conducted in Examples 1-6 and Comparative Examples 1-3 demonstrate that polyethylene grafted with maleic anhydride is a key component affecting the mechanical properties of the pipe. It improves the interfacial adhesion between the inorganic nanofiller and the organic polyethylene matrix, ensuring that stress is effectively transferred from the relatively flexible polymer matrix to the rigid filler particles, preventing interfacial debonding from becoming the starting point of failure. A good interface allows the elastomer particles to fully exert their toughening effects by inducing crazes and shear bands. The introduction of the antibacterial agent effectively increases the antibacterial properties of the pipe. Simultaneously, the polyethylene grafted with maleic anhydride ensures the uniform dispersion of the antibacterial agent, guaranteeing its exposure on the inner wall surface of the pipe and ensuring its antibacterial effect. The only difference between the components in Examples 1-6 is the amount of material used.

[0038] Working principle: Ultra-high molecular weight polyethylene has extremely long molecular chains and a relaxation time much longer than high-density polyethylene. Under the action of a circumferential shear flow field, the long chains of ultra-high molecular weight polyethylene are preferentially straightened to form a ridge fiber structure, which induces the high-density polyethylene molecular chains to grow epitaxially on the ridge fiber structure, ultimately resulting in a tandem crystal structure. Polyolefin elastomers and cyclic olefin copolymers are used as elastomer particles, which are uniformly dispersed in the polyethylene matrix. The dispersed elastomer particles absorb energy and passivate cracks, effectively compensating for the loss of toughness due to high orientation, and ensuring the safety of the pipe under impact and long-term dimensional stability. The chemical bonding between polyethylene grafted with maleic anhydride, organic imidized montmorillonite, and antibacterial agents allows inorganic nanofillers to be uniformly dispersed in the polyethylene matrix and form strong interfacial adhesion, preventing the inorganic nanofillers from agglomerating and becoming stress concentration points. This ensures that the antibacterial agent can be uniformly dispersed and partially exposed on the pipe surface, activating the antibacterial function.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A low-temperature resistant and creep-resistant PE water supply pipe, characterized in that: The PE water supply pipe comprises, by weight: 60-80 parts high-density polyethylene, 5-7 parts ultra-high molecular weight polyethylene, 0.5-2 parts organic imidium oxide, 2-5 parts polyolefin elastomer, 2-5 parts cyclic olefin copolymer, 1-2 parts compatibilizer, 0.1-0.5 parts antioxidant, and 0.1-0.5 parts antibacterial agent. The compatibilizer is polyethylene grafted with maleic anhydride, and the antibacterial agent is halloysite nanotube-supported cuprous oxide hybrid material.

2. The low-temperature resistant and creep-resistant PE water supply pipe according to claim 1, characterized in that: The raw materials for grafting maleic anhydride onto polyethylene include: high-density polyethylene, maleic anhydride, dicumyl peroxide, antioxidant 1010, and liquid paraffin. The mass ratio of high-density polyethylene, maleic anhydride, dicumyl peroxide, antioxidant 1010, and liquid paraffin is 100:0.5:0.1:0.1:

1.

3. The low-temperature resistant and creep-resistant PE water supply pipe according to claim 1, characterized in that: The preparation method of the halloysite nanotube-supported cuprous oxide hybrid material includes the following steps: Halloysite nanotubes were poured into deionized water, ultrasonically stirred for 30 min, sodium hydroxide solution was added, stirred at room temperature for 12 h, centrifuged, washed with deionized water until neutral, and dried at 80℃ to obtain pretreated halloysite nanotubes. The pretreated halloysite nanotubes were poured into deionized water, heated to 80°C, and hexadecyltrimethylammonium bromide was added. The mixture was stirred at a constant temperature for 2 hours, and copper sulfate pentahydrate solution was slowly added. Sodium hydroxide solution and ascorbic acid solution were added dropwise under stirring conditions. The mixture was cooled to room temperature, centrifuged, washed, and dried to obtain halloysite nanotube-supported cuprous oxide hybrid material.

4. The low-temperature resistant and creep-resistant PE water supply pipe according to claim 2, characterized in that: The preparation method of the polyethylene grafted with maleic anhydride includes the following steps: Liquid paraffin and high-density polyethylene granules were stirred in a high-speed mixer for 1 minute. Maleic anhydride, dicumyl peroxide, and antioxidant 1010 were added and stirred for 5 minutes. The mixture was then extruded and granulated using a twin-screw extruder to obtain polyethylene grafted with maleic anhydride.

5. The low-temperature resistant and creep-resistant PE water supply pipe according to claim 1, characterized in that: The preparation method of the organic imidacloprid includes the following steps: Immonite was poured into deionized water, stirred and allowed to stand for 24 hours. Hexadecyltrimethylammonium bromide was added, and the pH was adjusted to 3 using glacial acetic acid. The mixture was stirred at 75°C for 2 hours. Silane coupling agent KH-570 dissolved in anhydrous ethanol was added, and the mixture was stirred at 75°C for 4 hours. After centrifugation, washing, and drying, organic immonite was obtained.

6. The low-temperature resistant and creep-resistant PE water supply pipe according to claim 1, characterized in that: The polyolefin elastomer selected has a molecular weight of 7.95 × 10⁻⁶. 4 Low molecular weight polyolefin elastomers.

7. The low-temperature resistant and creep-resistant PE water supply pipe according to claim 1, characterized in that: The cyclic olefin copolymer is selected from low melt index cyclic olefin copolymers with a melt index range of 0.8-1.2 g / 10 min.

8. The low-temperature resistant and creep-resistant PE water supply pipe according to claim 1, characterized in that: The antioxidant is selected from one or more of antioxidants, such as antioxidant 1010 and antioxidant 168.

9. A manufacturing process for a low-temperature resistant and creep-resistant PE water supply pipe, applicable to the low-temperature resistant and creep-resistant PE water supply pipe described in any one of claims 1-8, characterized in that: The preparation process includes the following steps: S1. Weigh out high-density polyethylene, ultra-high molecular weight polyethylene, organic imidium monoxide, polyolefin elastomer, cyclic olefin copolymer, compatibilizer, antioxidant, and antibacterial agent, add them to a high-speed mixer and premix them evenly. Then, use a twin-screw extruder to granulate the mixture to obtain composite granules. S2. The composite granules are extruded through a single screw extruder, and the extruded melt is filled into the mold cavity. A circumferential shear force field is applied to the melt by the rotating mandrel of the rotary shearing device. After cooling and shaping, a PE water supply pipe is obtained.

10. The manufacturing process of a low-temperature resistant and creep-resistant PE water supply pipe according to claim 9, characterized in that: In step S1, the twin-screw extruder temperatures are: 150-170℃ in the feeding section, 180-200℃ in the melting section, 200-220℃ in the mixing section, and 210-230℃ at the die head. In step S2, the temperatures of the single screw extruder are as follows: feeding section 150-170℃, compression section 180-200℃, melt conveying section 180-200℃, and mandrel temperature of the rotary shearing device 190-200℃.

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