Scratch-resistant and biological adhesion-resistant PE threading pipe and preparation process thereof

Abstract

The invention discloses a scratch-resistant and biological adhesion-resistant PE threading pipe and a preparation process thereof, and relates to the technical field of PE threading pipes, the PE threading pipe comprises a polyethylene matrix layer and an elastic buffer layer covering the outer surface of the polyethylene matrix layer; the nano composite hardened layer covers the outer surface of the elastic buffer layer; the grafting anti-adhesion surface layer covers the outer surface of the nano-composite hardened layer; the elastic buffer layer and the polyethylene matrix layer form an integral structure through co-extrusion or fusion bonding; a coupling agent modified interface layer is arranged between the nano composite hardened layer and the elastic buffer layer; the grafted anti-adhesion surface layer is fixed on the surface of the nano composite hardened layer in a chemical grafting manner. Through the gradient multi-layer interface structure, on the premise that the flexibility and the integrated structure of the pipe are kept, a stable interlayer chemical and physical bonding interface is formed, the problem that a traditional hard coating is cracked or stripped due to interface stress concentration under bending or impact is solved, and the interlayer bonding reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of PE conduit technology, specifically to a scratch-resistant and bio-adhesion-resistant PE conduit and its manufacturing process. Background Technology

[0002] Polyethylene conduit is widely used due to its corrosion resistance, good processability, and low cost. However, during installation and use, the outer surface is prone to scratches and wear, leading to surface roughness and increased frictional resistance during threading; microscopic roughness and organic residues on the surface can become sites for microbial colonization. Existing modification methods mainly include single-layer hard coatings, low-friction additives, or release-type antibacterial agent coatings: single-layer hard coatings present a trade-off between scratch resistance and flexibility, and are prone to cracking or peeling under bending or impact; low-friction additives often reduce friction in the short term by releasing low-molecular-weight lubricants into the substrate, but their performance deteriorates after release; release-type antibacterial agents have issues with environmental release and long-term stability. Industrial continuous production places specific requirements on the adhesion strength between the coating and the substrate, the curing speed, and process compatibility.

[0003] Patent CN120040861B discloses a PE pipe and its preparation method. The patent achieves the formation of a hyperbranched structure within the material system, which enhances the interaction between molecular chains of the PE pipe substrate and further improves the mechanical properties of the PE pipe substrate, such as tensile strength, flexural strength, and impact strength. At the same time, it improves the processing performance of the PE pipe substrate, making it easier to flow and form during extrusion molding and other processing, and reducing the generation of defects.

[0004] The PE pipes produced by the aforementioned patents have good mechanical properties and anti-aging properties, but they cannot avoid the problem of cracking or peeling of traditional hard coatings due to interface stress concentration under bending or impact.

[0005] Therefore, this application proposes a scratch-resistant and bio-adhesion-resistant PE conduit and its preparation process, which forms a stable interlayer chemical and physical bonding interface by means of a gradient multilayer interface structure while maintaining the flexibility and integrated structure of the conduit. Summary of the Invention

[0006] The purpose of this invention is to provide a scratch-resistant and bio-adhesion-resistant PE conduit and its manufacturing process, in order to solve the technical problems mentioned in the background art, such as the easy occurrence of scratches and wear on the outer surface during laying and use, resulting in surface roughness and increased frictional resistance during threading; and the fact that surface micro-roughness and organic residues can become sites for microbial colonization.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a scratch-resistant and bio-adhesion-resistant PE conduit, wherein the PE conduit comprises, from the inside to the outside, the following components in a radial direction: Polyethylene matrix layer; An elastic buffer layer covering the outer surface of the polyethylene matrix layer; A nanocomposite hardening layer is applied to the outer surface of the elastic buffer layer; A grafted anti-adhesion surface layer is applied to the outer surface of the nanocomposite hardened layer; The elastic buffer layer and the polyethylene matrix layer are formed into an integral structure through co-extrusion or melt bonding. A coupling agent-modified interface layer is provided between the nanocomposite hardening layer and the elastic buffer layer; The grafted anti-adhesion surface layer is fixed to the surface of the nanocomposite hardened layer by chemical grafting.

[0008] Preferably, the elastic buffer layer is a thermoplastic elastomer layer, and the thermoplastic elastomer is selected from thermoplastic polyurethane, SEBS elastomer or elastic modified polyethylene. The thickness of the elastic buffer layer is 50-500μm.

[0009] Preferably, the nanocomposite hardening layer is composed of a UV-curable resin matrix, inorganic nanoparticles, and fluorine-containing lubricating microparticles; The UV-curing resin is an acrylate-based UV-curing resin.

[0010] Preferably, the inorganic nanoparticles are one or more of silicon dioxide, aluminum oxide, or titanium dioxide; Inorganic nanoparticles are surface-modified with silane coupling agents; The average particle size of the inorganic nanoparticles is 10-200 nm; The mass fraction of inorganic nanoparticles in the nanocomposite hardened layer is 0.5-10%.

[0011] Preferably, the fluorinated lubricating microparticles are polytetrafluoroethylene microparticles or fluorinated copolymer microparticles; The average particle size of the fluorinated lubricating microparticles is 0.1-10 μm; The mass fraction of fluorinated lubricating microparticles in the nanocomposite hardened layer is 0.1-5%.

[0012] Preferably, the nanocomposite hardening layer contains dispersed microcapsule structures; Microcapsules consist of a capsule wall material and a capsule core material; The core material is silicone oil or polydimethylsiloxane; The average particle size of the microcapsules is 1-50 μm; The mass fraction of microcapsules in the nanocomposite hardened layer is 0.1-5%.

[0013] Preferably, the grafted anti-adhesion surface layer is a polymer grafted layer formed by photo-initiated grafting reaction; The grafted layer is formed by the polymerization of zwitterionic monomers or amphiphilic monomers; The equivalent thickness of the grafted layer is 5nm-1μm.

[0014] Preferably, the preparation method includes the following steps: (1) Extruding the polyethylene matrix layer and simultaneously forming an elastic buffer layer on the outer surface of the matrix layer; (2) Perform surface activation treatment on the outer surface of the elastic buffer layer; (3) A nanocomposite coating system containing a coupling agent is coated on the outer surface of the surface-activated elastic buffer layer; (4) The nanocomposite coating system is cured by ultraviolet light to form a nanocomposite hardened layer; (5) Photo-initiated grafting reaction is performed on the surface of the nanocomposite hardened layer to form a grafted anti-adhesion surface layer.

[0015] Preferably, the surface activation treatment in (2) is one of corona treatment, plasma treatment or ultraviolet ozone treatment; Surface activation treatment introduces polar functional groups on the surface of the elastic buffer layer.

[0016] Preferably, in the nanocomposite coating system of (3): Inorganic nanoparticles are surface modified with silane coupling agents containing methacryloxy, amino, or epoxy groups before being added; The nanocomposite coating system is applied to the surface of the elastic buffer layer by spraying, casting, or scraping.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, through a gradient multilayer interface structure, forms a stable interlayer chemical and physical bonding interface while maintaining the flexibility and integrated structure of the pipe. This avoids the problem of cracking or peeling of traditional hard coatings due to interface stress concentration under bending or impact, improves the reliability of interlayer bonding, and maintains the integrity and service life of the coating under actual laying conditions. 2. This invention forms a continuous film on the surface with nano-reinforced hardness and local low-friction phase through a nano-composite hardening layer formula. It takes into account both the surface scratch resistance and hardness and low friction performance, avoids the problems of brittleness and high friction of single hard coatings, improves the surface nano hardness and wear resistance, and reduces the coefficient of friction, which facilitates wire threading and reduces roughness caused by wear. 3. This invention uses a non-release chemically grafted anti-adhesion layer to change the surface chemical composition and hydrophilicity / hydrophobicity distribution, thereby reducing the adhesion energy of microorganisms and organic pollutants in a physicochemical way. It replaces the release-type antibacterial and antifouling coating, eliminates the risk of environmental release, and provides long-term stable surface anti-adhesion properties. It reduces the initial colonization of bacteria and biofilms on the pipe surface, improves surface cleanliness, and reduces the frequency of maintenance. 4. This invention employs a micro-nano topological coupling self-healing lubrication strategy. Through a dual mechanism of reducing the actual contact area and releasing lubricant at the scratch, it maintains low friction and restores frictional performance after local damage. This solves the problems that a single microstructure cannot cope with the loss of lubrication performance after scratches and that a single lubricant release strategy may affect long-term consistency and surface finish. It also improves the short-term operability of the scratched area and reduces the fluctuation of threading resistance. Attached Figure Description

[0018] Figure 1 This is a simulation diagram of the Taber wear test results of the present invention; Figure 2 This is a simulation diagram showing the comparison results of the dry friction coefficient of the present invention; Figure 3 This is a simulation diagram of the adhesion test results of the present invention; Figure 4 This is a simulation diagram of the scratch self-healing test results of the present invention. Detailed Implementation

[0019] 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.

[0020] Example 1

[0021] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 The present invention provides an embodiment of a scratch-resistant and bio-adhesion-resistant PE conduit and its preparation process, which employs a baseline-type nanocomposite UV-cured hardening layer: Materials: Matrix material: High-density polyethylene (HDPE, type: PE100, melt index 0.25 g / 10 min); Elastic buffer layer material: Styrene-ethylene-butene-styrene copolymer (SEBS, hardness 50 Shore A); UV-curable resin: Low-viscosity acrylic UV-curable resin (prepolymer, molecular weight ~1000–3000 g / mol); Photoinitiator: Ketone phosphorylation initiator (BAPO, 2 wt% relative to resin); Inorganic nanoparticles: Hydrophobic Silica (average particle size 40 nm), modified with γ-methacryloxypropyltrimethoxysilane (MPS); Fluorine-containing lubricating microparticles: polytetrafluoroethylene (PTFE) spherical microparticles, average particle size 1.0 μm; Coupling agent primer: 0.5 wt% MPS solution diluted with ethanol (as primer); Grafting monomer: sulfobetaine monomer (SBMA); Initiation system (grafting): water / ethanol 1:1 solvent, photoinitiator: Irgacure 2959, 0.5 wt% (relative to monomer solution).

[0022] Layer thickness and content: Elastic buffer layer thickness: 200μm (co-extruded); Nanocomposite hardening layer thickness (after curing): 20μm; Mass fraction of inorganic nanoparticles in nanocomposite slurry: 5wt% (relative to dry base resin); Mass fraction of PTFE microparticles in nanocomposite slurry: 1wt%; Equivalent thickness of grafted anti-adhesion surface layer: 50nm (grafted chain layer measurement value).

[0023] Preparation process: PE / SEBS co-extrusion: Twin-screw extruder settings: PE melt temperature zone 210–230°C, SEBS melt temperature zone 190–210°C; extrusion die diameter 20mm; linear speed 10m / min; to obtain PE pipe blank with a 200μm SEBS outer layer.

[0024] Surface activation: The outer surface of SEBS was activated using a low-temperature plasma processor with a power of 100W, an argon flow rate of 2L / min, and a processing time of 60s.

[0025] Coupling agent primer: Apply 0.5wt% MPS / ethanol solution to the activated surface by spraying at a rate of 1g / m², and dry at 60°C for 2min.

[0026] Nanocomposite slurry preparation and coating: Formulation (by resin mass): 100 phr of UV-curable resin, 5 phr of MPS-modified SiO2, 1 phr of PTFE microparticles, and 2 phr of BAPO initiator; disperse at 25°C for 30 min using a high-speed disperser and degas; apply to the surface of the pipe using a trough-type scraper or narrow-slot casting coating machine, with the wet film thickness controlled at 30 μm (approximately 20 μm after curing).

[0027] UV curing: UV lamp (365nm mid-wavelength LED) irradiation intensity 1000mW / cm² 2 The transmission speed was adjusted accordingly to 10m / min to ensure two irradiations on one side, with a cumulative irradiation of 2s × 2 times.

[0028] Grafting layer formation (photoinitiated grafting): The pipe is immersed in a 10wt% SBMA / water-ethanol (1:1) solution, 0.5wt% photoinitiator is added, and it is irradiated under 365nm UV for 60s. Then it is taken out, rinsed with deionized water and dried with hot air at 60°C for 10min to form a grafting layer with an equivalent thickness of about 50nm.

[0029] Test methods: Layer thickness measurement: measured using a cross-sectional optical microscope or a cross-sectional scanning electron microscope; Graft layer confirmation: surface functional group changes were detected by XPS and ATR=FTIR; Bond strength measurement: tensile peel test (clamping length 50 mm, tensile rate 10 mm / min) was used to record the peel force (N / cm).

[0030] Example 2

[0031] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 One embodiment of the present invention provides: a scratch-resistant and bio-adhesion-resistant PE conduit and its preparation process, employing a TPU buffer layer and TiO2 nanoparticles in a formulation: Materials: Matrix material: High-density polyethylene (PE100); Elastic buffer layer material: Thermoplastic polyurethane (TPU, melt viscosity adapted for extrusion); UV-curable resin: Acrylic resin (same as Example 1); Photoinitiator: Phenyl di(2,4,6-trimethylbenzyloxy)phosphoryl oxide (BAPO, 2wt%); Inorganic nanoparticles: MPS-modified nano-titanium dioxide (TiO2, average particle size 50nm), 3wt% (relative to resin); Fluorinated lubricating microparticles: Fluorinated copolymer microparticles, average particle size 0.5μm, 0.5wt%; Grafted monomer: Quaternary ammonium zwitterionic copolymer monomer (Example formulation: SBMA and ethyl methacrylate mixed in a 1:1 molar ratio).

[0032] Layer thickness and content: Buffer layer thickness: 150μm; Nanocomposite hardening layer thickness: 15μm; TiO2 content: 3wt%; Fluorine-containing particle content: 0.5wt%.

[0033] Preparation process (same as in Example 1): Parameter differences: Co-extrusion parameters: TPU melt temperature range 220–240°C, linear speed 12 m / min; Surface activation: Corona treatment, power 5 kV, processing speed 8 m / min, processing time equivalent to 1 pass; Coating method: Closed-loop casting, wet film thickness 25 μm; UV curing: LED UV intensity 1200 mW / cm², conveyor speed 12 m / min, single irradiation 1.5 s; Grafting conditions: In an ethanol / water 1:1 solution containing 12 wt% zwitterionic comonomer, photoinitiator 0.6 wt%, UV irradiation for 90 s.

[0034] Detection methods: Nanoparticle dispersion uniformity: inspected by transmission electron microscopy (TEM) and beam scanning; UV curing conversion rate: measured by FTIR to measure the reduction of the C=C peak.

[0035] Example 3

[0036] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 One embodiment of the present invention provides: a scratch-resistant and bio-adhesion-resistant PE conduit and its preparation process, using a micro / nano topological template imprinting + pre-embedded microcapsule self-healing system: Materials: Matrix: PE100; Buffer layer: SEBS, thickness 300μm; Nanocomposite hardening layer matrix: acrylate resin + MPS-modified SiO2 (4wt%) + PTFE microparticles (1wt%) + microcapsules (2wt%); Microcapsules: Capsule wall material is urea-formaldehyde resin or chitosan-formaldehyde cross-linked shell, and the core is low-viscosity polydimethylsiloxane (PDMS, viscosity ~100cSt), with an average particle size of 10μm and a mass fraction of 2wt%.

[0037] Layer thickness and content: Thickness of nanocomposite hardened layer (after curing): 25μm;

[0038] Preparation process: Surface activation was the same as in Example 1 (plasma); nanocomposite slurry was coated to a wet film thickness of 35 μm; nano-template imprinting: before the coating solution was fully cured, a stainless steel roller with nano-column pattern was used to imprint the surface at 80°C, a linear speed of 5 m / min, and an imprinting pressure of 1.5 MPa, followed immediately by UV (365 nm, 900 mW / cm²) exposure. 2 Curing for 2 seconds preserves the micro-nano imprint; Grafting layer: using 8wt% SBMA solution, photoinitiated for 60 seconds.

[0039] Selection of molding timing: The coating liquid viscosity reaches a window where it is deformable but still transferable (10-30s after coating) to obtain a complete microstructure; Microcapsule distribution: Pre-mix with resin and degas to avoid high shear breaking of microcapsules.

[0040] Example 4

[0041] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 One embodiment of the present invention provides: a scratch-resistant and bio-adhesion-resistant PE conduit and its preparation process, which uses a thermosetting epoxy and amine system hardening layer (replacing UV curing) and Al2O3 particles: Materials: Matrix PE100; Buffer layer: Thermoplastic polyolefin elastomer (elastic modified PE), 100μm thick; Thermosetting resin: Epoxy resin (low viscosity epoxy prepolymer) and multifunctional amine curing agent; Inorganic nanoparticles: Alumina modified with amine and aminosilane, average particle size 80nm, mass fraction 4wt%; Fluorine-containing lubricating phase: PTFE microparticles 0.5wt%; Grafting monomers and grafting method: The surface is first activated by corona discharge and then coated with an initiation-type grafting underlayer (persulfate system), followed by thermal initiation of propylene amphoteric monomers at 70℃ to form a grafting layer.

[0042] Layer thickness and parameters: Thermosetting hardened layer thickness: 30μm (resin to hardener ratio 100:10wt%); Curing conditions: curing temperature 80℃, curing time 30min, followed by curing at 120℃ for 10min to complete crosslinking.

[0043] Preparation process: Co-extruded PE or elastically modified PE layer (as in Example 1); Surface activation: Corona treatment, treatment parameters are shown in Example 2; Coupling agent primer: Spray with a 0.8wt% solution containing epoxy active silane and allow to dry; Thermosetting slurry preparation: 100 phr epoxy resin, 10 phr amine curing agent, 4 phr Al2O3, 0.5 phr PTFE, mixed and degassed at low speed; Coating thickness 40μm (wet film), preheat oven to 60℃ for 2min to remove solvent, then heat curing at 80℃ for 30min, then heating to 120℃ for 10min; Graft layer formation: Coat the surface of the cured layer with persulfate initiator solution and add 10wt% amphoteric monomer solution, heat treat at 70℃ for 30min, clean and dry.

[0044] Example 5

[0045] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 The present invention provides an embodiment of a scratch-resistant and bio-adhesion-resistant PE conduit and its manufacturing process, wherein a high-density grafted layer and a continuous wire are demonstrated. Materials and Formulation: Matrix: Polyethylene (PE100); Buffer Layer: SEBS, 250μm thick; Nanocomposite Hardening Layer Matrix: Acrylic resin + MPS modified SiO2 (6wt%) + PTFE (1wt%); Grafting Monomer: SBMA (15wt% water and ethanol solution); Grafting Initiator: Photoinitiator 0.6wt%.

[0046] Process (Example of continuous line parameters): Co-extrusion line capacity template: production line diameter 20mm, line speed 8-12m / min; Plasma activation unit: power 120W, gas mixture Ar:O2:9:1, distance between processing head and tube 5mm; Coupling agent spraying and drying: MPS, ethanol 0.6wt%, infrared hot air 80℃×30s; Nanocomposite coating: trough coating, wet film thickness 30μm; UV curing: LED 1200mW / cm² 2 2 seconds per shot; Grafting station: The impregnation tank contains 15wt% SBMA solution, and the pipe passes through the impregnation + UV curing zone (365nm, 1500mW / cm). 2 Irradiate for 60 seconds, then degas and dry under vacuum at 60°C for 5 minutes; Quality inspection: online optical inspection (surface defect identification), thickness measurement (laser displacement thickness gauge) and random chemical analysis (XPS random inspection once every 1000m).

[0047] Example 6

[0048] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 The present invention provides an embodiment of a scratch-resistant and bio-attachment-resistant PE conduit and its preparation process, including experimental formulation and testing procedures. Material formulation: Nanocomposite slurry (formulation by mass): 100g acrylic acid prepolymer, 5g MPS-modified SiO2, 1g PTFE microparticles, 2g BAPO initiator, 2g microcapsules (PDMS), 10g solvent (isopropanol); Grafting solution: 10g SBMA, 45g deionized water, 45g ethanol, 0.5g Iegacure 2959.

[0049] Preparation process (laboratory steps): The acrylic prepolymer was mixed with isopropanol, MPS-SiO2 was added, and the mixture was dispersed using a shear disperser at 2000 rpm for 30 min. PTFE and microcapsules were then added, and the mixture was degassed for 20 min. Plasma treatment (100W, 60s) was performed on PS / SEBS co-extruded samples (SEBS thickness 200μm). Spraying nanocomposite slurry (wet film 30μm) using a UV lamp (365nm) at 1000mW / cm 2 Irradiate for 2 seconds twice; The cured sample was immersed in the grafting solution and irradiated at 365 nm for 60 seconds. After removal, it was washed with deionized water and dried at 60 °C for 10 minutes.

[0050] Testing process and parameters: Surface microstructure: The outer surface morphology was photographed using a scanning electron microscope (SEM) at 5kV, with magnifications of 5000× and 20000×. Nanoparticle dispersion: 80 nm thick TEM slices were prepared to observe the dispersion state of SiO2; Chemical composition of the grafted layer: N1s, S2p, and C1s peaks were determined by XPS, and the changes in elemental ratios before and after grafting were compared. Interlayer adhesion: Cross-cut adhesion test (cross-cut method) and peel load measurement, record peel force (N / cm). Scratch resistance test procedure: Use Taber Abraser (grind wheel load 500g, wear disc CS-10, rotation speed 1000 rpm) and record the wear mass loss (mg). Self-healing release test: Scratches were made on the sample surface (1 mm deep with a standard needle tip), and then the sample was left at room temperature for 24 hours to check the lubricant precipitation in the microcapsule rupture area (optical microscopy).

[0051] I. Performance Testing Methods: 1. Layer thickness measurement: Cross-sectional optical microscope and cross-sectional SEM measurement, take the average of 5 points, unit μm; 2. Surface roughness (Ra): Stylus type roughness meter, measures the average value at 3 orientation positions, unit nm / μm (results are expressed in nm or μm); 3. Surface hardness: Nanoindentation (Berkovich needle), load 5mN, averaged 10 times, results are expressed in GPa; 4. Taber wear: Record the mass loss in mg according to ASTM D4060 (CS-10 disc, 500g load, 1000 rpm); 5. Coefficient of dry friction (COF): Needle disc and pin disc test (similar to ASTM G99), load 2N, sliding speed 50mm / s, record steady-state COF; 6. Recovery of friction coefficient after scratch: A standard scratch (approximately 20 μm deep) was artificially created on the sample. The COF was measured immediately after the scratch was recorded and again after 24 hours. 7. Adhesion and bonding (peel strength): 90° peel test, unit N / cm; and cross-hatching adhesion test (ASTM D3359) rating (5B=best, 0B=worst). 8. Surface chemistry and grafting confirmation: XPS (surface ~10nm), recording the percentage of key element atoms (such as N, S, etc.); ATR-FTIR for functional group identification; 9. Bacterial Adhesion Test: Following standard bacterial adhesion counting methods (using E. coli ATCC25922 and S. aureus ATCC6538 as model bacteria), after 24 hours of contact in LB broth, the bacteria were gently rinsed and recovered by sonication and stirring. After dilution, CFU / cm³ were counted on plates. 2 ; 10. Accelerated aging: QUV (UV-A 340nm, 60℃ temperature bath), after 500h of exposure, repeat the above key tests (Taber, COF, graft layer XPS).

[0052] II. Key Reference Values ​​for the Control Sample (Unmodified PE Pipe) Surface Ra: 1.2 μm; Surface nanohardness (nanoindentation): 0.08 GPa; Taber wear mass loss (500g, 1000 rpm): 120mg; COF (dry): 0.25; 90° peel force: Repeatable adhesion not measured (coating not present), cross-cut score N / A (no coating); E. coli adhesion (CFU / cm) 2 ): 1.2×10 5 ; S. aureus adhesion (CFU / cm) 2 ): 8.5×10 4 .

[0053] III. Summary of test results for the examples (as shown in Tables A, B, and C below) Table A - Key Physical, Chemical and Mechanical Indicators; ; Table B - Indicators of bio-attachment and self-healing scratch recovery; ; Table C - Key parameters after accelerated aging; ; Data Summary: All examples containing the nanocomposite hardening layer showed significantly lower Taber mass loss (12–30 mg) than the unmodified control (120 mg), indicating that the hardening layer formed by the nanofiller and UV / thermosetting resin significantly alters the surface mechanical wear resistance. Example 3 (molded micro / nanotope + microcapsules) achieved the lowest and highest combination of Taber and hardness (12 mg, 1.25 GPa).

[0054] The PTFE / fluorine-containing nanocomposite layer reduced the steady-state COF to 0.10–0.16 (compared to 0.25 in the control). Examples 3 and 5 showed the lowest COF (0.10–0.11).

[0055] Changes in graft layer Nat.% (2.4–3.3 at.%) and contact angle (28°–40°) corresponded to a significant decrease in bacterial adhesion (E. coli from 1.2 × 10⁻⁶). 5 Reduced to 0.98×10 3 –4.5×10 3 Example 5 showed the highest grafting density (N 3.3 at.%) and the lowest bacterial adhesion.

[0056] The COF of the samples with pre-embedded microcapsules (Examples 1, 3, 5, and 6) decreased significantly within 24 hours after scratching, accompanied by optically visible lubricant precipitation areas (1.5–3% of surface area), indicating that the microcapsule strategy can provide lubrication compensation to local scratched areas in the short term.

[0057] The UV-cured acrylate system (Examples 1, 3, 5, 6) showed little change in performance after accelerated aging (Taber +8%–+14%), while the thermosetting epoxy system (Example 4) showed more significant degradation (Taber +22%, with greater loss of graft layer).

[0058] Under continuous line conditions (Example 5), after parameter optimization, a relatively stable grafted layer (XPSN 3.3 at.%) was obtained, and the peel strength and cross score both met the 5B / higher bond strength requirements.

[0059] Working Principle: The conduit, arranged radially from the inside out, consists of: a polyethylene matrix layer, an extruded elastic buffer layer, a coupling agent-modified interface layer, a nanocomposite hardening layer, and a chemically grafted anti-adhesion surface layer. The elastic buffer layer is primarily composed of thermoplastic elastomers, which are co-extruded or melt-bonded with the PE matrix to form an integrated structure. The interface layer contains a silane coupling agent, which improves the adhesion between the elastic layer and the subsequent hardening layer through chemical bonding. The nanocomposite hardening layer consists of an acrylate photocurable resin matrix, surface-modified inorganic nanoparticles, and fluorinated solid lubricating microparticles, forming a continuous and dense hardened film through photocuring or thermal curing. The grafted anti-adhesion surface layer is formed by photo-initiated or thermally initiated graft polymerization on the surface of the cured layer, creating a high-density zwitterionic or amphiphilic polymer chain layer.

[0060] Nanoparticles form a nano-reinforcing phase within the polymer matrix, increasing surface hardness and altering the microscopic contact geometry. Simultaneously, fluorinated microparticles form a low-friction phase to reduce the coefficient of friction. An elastic buffer layer absorbs and disperses stress under external forces, reducing the risk of crack initiation caused by load on the hardened layer. Grafted polymer chains are fixed to the hardened layer surface by chemical or strong physical bonds, altering the surface's hydrophilic / hydrophobic properties and reducing reversible adhesion energy at the nanoscale, thereby decreasing the initial adhesion and retention probability of microorganisms and organic pollutants.

[0061] Microcapsules are pre-embedded in the hardened layer formulation. When local scratches cause damage to the microstructure, the microcapsules rupture and release lubricant to fill the exposed area and compensate for local friction. The entire manufacturing process adopts a continuous process: PE / elastic layer co-extrusion - surface activation - coupling agent primer - nanocomposite slurry coating - UV thermosetting - graft polymerization, thereby forming finished pipes with stable interfacial bonding and controllable interfacial microstructure on the industrial production line.

[0062] 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 scratch-resistant and bio-adhesion-resistant PE conduit, characterized in that: The PE conduit comprises, from the inside to the outside, the following components radially: Polyethylene matrix layer; An elastic buffer layer covering the outer surface of the polyethylene matrix layer; A nanocomposite hardening layer is applied to the outer surface of the elastic buffer layer; A grafted anti-adhesion surface layer is applied to the outer surface of the nanocomposite hardened layer; The elastic buffer layer and the polyethylene matrix layer are formed into an integral structure through co-extrusion or melt bonding. A coupling agent-modified interface layer is provided between the nanocomposite hardening layer and the elastic buffer layer; The grafted anti-adhesion surface layer is fixed to the surface of the nanocomposite hardened layer by chemical grafting.

2. The scratch-resistant and bio-adhesion-resistant PE conduit according to claim 1, characterized in that: The elastic buffer layer is a thermoplastic elastomer layer, and the thermoplastic elastomer is selected from thermoplastic polyurethane, SEBS elastomer or elastic modified polyethylene. The thickness of the elastic buffer layer is 50-500μm.

3. The scratch-resistant and bio-adhesion-resistant PE conduit according to claim 2, characterized in that: The nanocomposite hardening layer is composed of a UV-curable resin matrix, inorganic nanoparticles, and fluorine-containing lubricating microparticles. The UV-curing resin is an acrylate-based UV-curing resin.

4. The scratch-resistant and bio-adhesion-resistant PE conduit according to claim 3, characterized in that: The inorganic nanoparticles are one or more of silicon dioxide, aluminum oxide, or titanium dioxide. Inorganic nanoparticles are surface-modified with silane coupling agents; The average particle size of the inorganic nanoparticles is 10-200 nm; The mass fraction of inorganic nanoparticles in the nanocomposite hardened layer is 0.5-10%.

5. The scratch-resistant and bio-adhesion-resistant PE conduit according to claim 4, characterized in that: The fluorinated lubricating microparticles are polytetrafluoroethylene microparticles or fluorinated copolymer microparticles; The average particle size of the fluorinated lubricating microparticles is 0.1-10 μm; The mass fraction of fluorinated lubricating microparticles in the nanocomposite hardened layer is 0.1-5%.

6. The scratch-resistant and bio-adhesion-resistant PE conduit according to claim 5, characterized in that: The nanocomposite hardening layer contains dispersed microcapsule structures; Microcapsules consist of a capsule wall material and a capsule core material; The core material is silicone oil or polydimethylsiloxane; The average particle size of the microcapsules is 1-50 μm; The mass fraction of microcapsules in the nanocomposite hardened layer is 0.1-5%.

7. The scratch-resistant and bio-adhesion-resistant PE conduit according to claim 1, characterized in that: The grafted anti-adhesion surface layer is a polymer grafted layer formed by photo-initiated grafting reaction; The grafted layer is formed by the polymerization of zwitterionic monomers or amphiphilic monomers; The equivalent thickness of the grafted layer is 5nm-1μm.

8. A manufacturing process for a scratch-resistant and bio-adhesion-resistant PE conduit, applicable to the scratch-resistant and bio-adhesion-resistant PE conduit as described in claim 6, characterized in that: The preparation method includes the following steps: (1) Extruding the polyethylene matrix layer and simultaneously forming an elastic buffer layer on the outer surface of the matrix layer; (2) Perform surface activation treatment on the outer surface of the elastic buffer layer; (3) A nanocomposite coating system containing a coupling agent is coated on the outer surface of the surface-activated elastic buffer layer; (4) The nanocomposite coating system is cured by ultraviolet light to form a nanocomposite hardened layer; (5) Photo-initiated grafting reaction is performed on the surface of the nanocomposite hardened layer to form a grafted anti-adhesion surface layer.

9. The manufacturing process of a scratch-resistant and bio-adhesion-resistant PE conduit according to claim 8, characterized in that: The surface activation treatment in (2) is one of corona treatment, plasma treatment or ultraviolet ozone treatment; Surface activation treatment introduces polar functional groups on the surface of the elastic buffer layer.

10. The manufacturing process of a scratch-resistant and bio-adhesion-resistant PE conduit according to claim 8, characterized in that: In the nanocomposite coating system described in (3): Inorganic nanoparticles are surface modified with silane coupling agents containing methacryloxy, amino, or epoxy groups before being added; The nanocomposite coating system is applied to the surface of the elastic buffer layer by spraying, casting, or scraping.

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