Preparation method of conductive weather-resistant composite material

Abstract

The invention belongs to the technical field of polymer composite materials, and discloses a conductive weather-resistant composite material which is prepared from the following raw materials in percentage by weight: matrix resin, conductive filler and a functional additive. The researched and developed conductive weather-resistant composite material is remarkable in function, and a unique raw material formula and diversified order-of-magnitude optimization are adopted in the aspect of electrical performance. A multi-layer conductive network with the volume omega is constructed, the important composition of ordered conductor carriers is realized, the interface and volume resistivity omega can be controlled to be 1.0 * 10 < 3 > omega, 1.0 * 10 < 5 > omega, 1.0 * 10 < 4 > omega and 1.0 * 10 < 6 > omega through doping, dispersing, copolymerizing, chelating and compatibility of the carriers in different resins, and the electrical property attenuation is kept to be not greater than 2 seconds for a long-acting effect. An anti-aging and weather-resistant auxiliary agent is further added, so that the safety and the reliability of the material are promoted to be stable, the comprehensive performance is improved, the density is low, and the mechanical property is good; static power accumulation caused by collision of propellers and airflow of the special unmanned aerial vehicle in severe weather is effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials technology, specifically a method for preparing a conductive and weather-resistant composite material. Background Technology

[0002] In the application of special-purpose unmanned aerial vehicles (UAVs), the surface material of the propeller, as a key component, directly affects the safe operation of the UAV in complex environments. Especially under severe weather conditions such as thunderstorms, static electricity easily accumulates on the propeller surface due to friction and induction. Most existing materials used for the surface of special-purpose UAV propellers suffer from poor anti-static properties. Static electricity accumulation not only interferes with the normal operation of the UAV's internal electronic equipment, leading to abnormal flight data and communication interruptions, but can also trigger electrostatic discharge, generating electric sparks. This poses a significant safety hazard in thunderstorms, seriously threatening the flight safety of the UAV and rendering it unusable in severe weather conditions, greatly limiting the performance and application scope of special-purpose UAVs in complex environments. Therefore, developing a propeller surface material with excellent anti-static properties and adaptability to severe weather is of significant practical importance. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a conductive and weather-resistant composite material to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a conductive and weather-resistant composite material, which is composed of the following raw materials by weight percentage: The matrix resin is composed of bisphenol A type epoxy resin E-51 and thermoplastic polyurethane elastomer PU in a mass ratio of 2:1, wherein epoxy resin E-51 accounts for 40 wt% and polyurethane PU accounts for 20 wt%. Conductive filler: composed of networked polypyrrole (PPy), carboxylated multi-walled carbon nanotubes (MWCNT), and high-structure conductive carbon black (KB) in a mass ratio of 1.5:1:1, wherein PPy accounts for 15 wt%, MWCNT accounts for 10 wt%, and KB accounts for 10 wt%. Functional additives: composed of hindered amine light stabilizers, benzotriazole ultraviolet absorbers UV-P, silane coupling agents KH-560, and superdispersants BYK-110 in a mass ratio of 1:1:1:2, wherein the heat stabilizer accounts for 1 wt%, the ultraviolet absorber accounts for 1 wt%, the coupling agent accounts for 1 wt%, and the dispersant accounts for 2 wt%.

[0005] Preferably, the method for preparing the composite material includes: Step 1, Preprocessing stage: Multi-walled carbon nanotubes (MWCNTs) and conductive carbon black (KB) were placed in 68% concentrated nitric acid and refluxed at 80°C for 2 hours. After washing with deionized water until pH=7, they were dried in a vacuum drying oven at 80°C for 12 hours. Epoxy resin E-51 and polyurethane PU were added to a reactor at a mass ratio of 2:1, followed by heat stabilizer and ultraviolet absorber. The mixture was mechanically stirred at 60°C for 1 hour at a stirring speed of 300 rpm to form a homogeneous premixed resin. Step 2, Conductive filler dispersion stage: The modified MWCNT, KB and networked polypyrrole PPy were added to the premixed resin in sequence, and the mixture was treated with an ultrasonic cell disruptor at 400W power and 20kHz frequency for 30 minutes. During the ultrasonic process, the material temperature was controlled to be ≤40℃. Transfer to a high-speed disperser and continue stirring at 3000 rpm for 1 hour. During this time, add coupling agent KH-560 and dispersant BYK-110 to form a conductive resin system with uniformly dispersed filler. Step 3, Molding and Processing Stage: The mixture is injected into a mold preheated to 120°C with a mold dimensional accuracy of ±0.02mm. It is then held under 10MPa pressure and heated to 150°C at a rate of 2°C / min, and cured for 2 hours. After naturally cooling to 60℃, the material is demolded and a transparent anti-corrosion coating is applied to the surface using an electrostatic spraying process. The spraying voltage is 60kV, and the coating thickness is monitored in real time by a film thickness gauge with an error of ±2μm. The final product is cured at 80℃ for 1 hour, then cut, trimmed, and packaged.

[0006] Preferably, the networked polypyrrole (PPy) is synthesized via a soft template method, specifically as follows: Using sodium dodecylbenzenesulfonate as a template agent, pyrrole monomers were polymerized in an ice bath at 0°C for 12 hours under the action of ammonium persulfate oxidant. After repeated washing with ethanol, the wire diameter was controlled at 20-35 nm to form an interpenetrating three-dimensional conductive network structure. The carboxylated multi-walled carbon nanotubes (MWCNTs) are oxidized with mixed acid (concentrated sulfuric acid: concentrated nitric acid = 3:1), with a diameter of 10-20 nm, a length of 5-15 μm, and a surface carboxyl content ≥1.2 wt%. The high-structure conductive carbon black (KB) has a particle size distribution D50 of 30-50 nm and a specific surface area ≥1200 m² / g.

[0007] Preferably, the epoxy value of epoxy resin E-51 in the matrix resin is 0.51 mol / 100g, and the Shore hardness of polyurethane PU is A85±5; the heat stabilizer in the functional additives is poly[(6-morpholine-s-triazine-2,4-diyl)[2,2,6,6-tetramethyl-4-piperidinyl)imino]], the ultraviolet absorber is 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, the coupling agent KH-560 has the molecular formula C9H20O5Si, and the dispersant BYK-110 is a copolymer solution containing acidic groups.

[0008] Preferably, the surface resistivity of the composite material is controlled to be 10. 6 Ω~10 11 Ω, tested according to GJB3007 (SJ / T10694) standard; under a 5kV applied voltage, the time required for electrostatic decay to reach 10% is ≤0.5s, the test method refers to ASTM D257; the material density is ≤1.2g / cm³, determined according to GB / T 1033.1-2008 method A; tensile strength ≥50MPa, flexural modulus ≥2000MPa, impact strength ≥40kJ / m², respectively performed according to GB / T 1040.2, GB / T 9341, and GB / T 1843 standards.

[0009] Preferably, the surface of the composite material is coated with a transparent anti-corrosion coating with a thickness of 10-20 μm. The coating material is a fluorocarbon resin-based compound, specifically composed of perfluoropolyether modified acrylate and nano-silica in a mass ratio of 95:5. The curing process is baking at 120°C for 30 minutes. The coating contact angle is ≥110°, and the weather resistance meets the GB / T 1865-2009 standard.

[0010] Preferably, the concentrated nitric acid treatment process in step one can be replaced by a mixed acid oxidation of 30% hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:3, with a treatment temperature of 70°C and a time of 1.5 hours; during the preparation of the premixed resin, the mixing order of epoxy resin and polyurethane is as follows: first add polyurethane and preheat to 60°C, then slowly add epoxy resin to avoid local overheating and clumping.

[0011] Preferably, in step two, the ultrasonic dispersion adopts a pulse working mode, with 10 seconds of operation and 5 seconds of pause, for a total effective ultrasonic time of 25 minutes; during the high-speed dispersion process, the temperature of the material barrel is controlled to ≤45℃ by circulating water cooling; after dispersion, a laser particle size analyzer is used to detect the particle size distribution of the filler to ensure that D90≤80μm.

[0012] Preferably, the composite material employs a filler gradation design, enabling PPy to construct a long-range conductive network, MWCNT to fill the network gaps, and KB to form micro-area conductive channels. These three components synergistically achieve a low percolation threshold. The material density is further controlled by adding 5 wt% hollow glass microspheres (density 0.6 g / cm³), resulting in a final density ≤1.18 g / cm³, while maintaining a surface resistivity of 8.2 × 10⁻⁶. 7 The performance includes Ω and electrostatic decay time ≤0.5s.

[0013] Preferably, the composite material has been verified by a third-party testing institution to have a surface resistivity change of ≤1 order of magnitude after 500 hours of damp heat aging test at 85℃ and 85% relative humidity; after 300 hours of xenon lamp aging (wavelength 300-400nm, irradiance 0.51W / m²), the material color difference ΔE ≤1.5, with no visible cracking, blistering or fading; in the propeller application verification, 50 take-off and landing tests were completed in thunderstorm weather (wind speed 12m / s, rainfall 50mm / h), the radar wave reflectivity was normal, and the flight data was not abnormally interrupted.

[0014] The beneficial effects of this invention are as follows: 1. The conductive and weather-resistant composite material developed in this invention exhibits significant functionalities. In terms of electrical properties, it features a unique raw material formulation and multi-level optimization. A multi-layered conductive network (Ω) is constructed, realizing a crucial component of ordered conductor charge carriers. Through doping, dispersing, copolymerizing, and chelating charge carriers in different resins, the interfacial and volume resistivity (Ω) can be controlled within 1.0 × 10⁻⁶. 3 Ω∼1.0×10 5 Ω∼1.0×10 4 Ω∼1.0×10 6 Ω, maintaining electrical performance degradation of no more than 2 seconds for a long-lasting effect. Through specialized and innovative technical methods and optimized preparation processes, the material undergoes multi-element fine processing to ensure uniform dispersion of the filler phase and dense composite structure. Further addition of aging-resistant and weather-resistant additives promotes material safety and reliability stability, enhances overall performance, and results in low density and excellent mechanical properties. It effectively solves the problem of static electricity accumulation caused by propeller collisions with airflow in severe weather conditions for special-purpose drones. This static electricity is instantly neutralized by passive discharge to the blue sky and white clouds, greatly improving endurance and ensuring the safe operation of all drone performance data and its widespread application.

[0015] 2. This invention significantly improves the comprehensive performance of the composite material through innovative preparation processes. In the pretreatment stage, multi-walled carbon nanotubes (MWCNTs) and conductive carbon black (KB) are treated with concentrated nitric acid or mixed acid oxidation, increasing their surface activity and facilitating uniform dispersion in the matrix resin. Precise control of the mixing sequence and temperature during premixed resin preparation avoids localized overheating and agglomeration, ensuring the uniformity of the resin system. In the conductive filler dispersion stage, a combination of ultrasonic cell disruptors and high-speed dispersers is used to uniformly disperse the filler in the resin. Laser particle size analyzers are used to detect the filler particle size distribution, ensuring D90 ≤ 80 μm, further improving the material's electrical and mechanical properties. In the molding and processing stage, strict control of mold temperature, pressure, and heating rate ensures a dense internal structure and optimal performance indicators, with tensile strength ≥ 50 MPa, flexural modulus ≥ 2000 MPa, and impact strength ≥ 40 kJ / m², meeting the requirements for use by special UAV propellers under complex stress environments.

[0016] 3. This invention further expands the application range and reliability of composite materials by optimizing material structure and surface treatment. Through filler gradation design, PPy constructs a long-range conductive network, MWCNT fills the network gaps, and KB forms micro-area conductive channels. These three elements work synergistically to achieve a low percolation threshold, reducing the amount of conductive filler used and lowering material costs while maintaining conductivity. Adding 5wt% hollow glass microspheres further regulates the material density, achieving a final density ≤1.18 g / cm³, while maintaining a surface resistivity of 8.2 × 10⁻⁶. 7 The Ω and electrostatic decay time of ≤0.5s reduce the weight of the propeller and improve the flight efficiency of the UAV. The transparent anti-corrosion coating sprayed on the surface is made of fluorocarbon resin-based compound. After curing, the coating contact angle is ≥110°, which has good anti-fouling properties, reducing the adhesion of dust, rainwater and other impurities on the propeller surface and reducing the impact on flight performance. Verified by a third-party testing agency, after 500 hours of damp heat aging test at 85℃ and 85% relative humidity, the surface resistivity change is ≤1 order of magnitude. After 50 take-off and landing tests in thunderstorm weather, the radar wave reflectivity is normal and the flight data is not abnormally interrupted, which fully demonstrates the reliability and stability of the composite material under harsh weather conditions and provides a strong guarantee for the safe flight of special UAVs in complex environments. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the preparation steps of the conductive and weather-resistant composite material of the present invention. Detailed Implementation

[0018] 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.

[0019] like Figure 1 As shown in the figure, this invention provides a composite material with excellent electrical conductivity and weather resistance, the raw material composition and preparation process of which are as follows: I. Raw material composition and proportions Matrix resin system Bisphenol A type epoxy resin E-51 and thermoplastic polyurethane elastomer PU (Shore hardness A85±5) were compounded at a mass ratio of 2:1, with epoxy resin E-51 accounting for 40wt% and polyurethane PU accounting for 20wt%. The epoxy value of epoxy resin E-51 is 0.51mol / 100g, and the addition of polyurethane can improve the toughness of the material.

[0020] conductive filler system It is composed of networked polypyrrole (PPy), carboxylated multi-walled carbon nanotubes (MWCNT), and high-structure conductive carbon black (KB) in a mass ratio of 1.5:1:1, specifically: PPy 15wt%, MWCNT 10wt%, and KB 10wt%.

[0021] PPy: Synthesized via a soft template method, using sodium dodecylbenzenesulfonate as a template agent. Pyrrole monomers are polymerized in an ice bath at 0°C for 12 hours under the action of ammonium persulfate oxidant. After repeated washing with ethanol, the wire diameter is controlled at 20-35 nm, forming an interpenetrating three-dimensional conductive network structure.

[0022] MWCNT: Oxidized by mixed acid (concentrated sulfuric acid: concentrated nitric acid = 3:1), with a diameter of 10-20nm, a length of 5-15μm, and a surface carboxyl content ≥1.2wt%.

[0023] KB: Particle size distribution D50 is 30-50nm, specific surface area ≥1200m² / g, and high structural characteristics are conducive to the formation of micro-region conductive channels.

[0024] Functional additive system It is composed of hindered amine light stabilizer, benzotriazole ultraviolet absorber UV-P, silane coupling agent KH-560 (molecular formula C9H20O5Si), and superdispersant BYK-110 (a copolymer solution containing acidic groups) in a mass ratio of 1:1:1:2. The specific ratio is: 1 wt% heat stabilizer, 1 wt% ultraviolet absorber, 1 wt% coupling agent, and 2 wt% dispersant.

[0025] Heat stabilizer: Poly[(6-morpholino-s-triazine-2,4-diyl)[2,2,6,6-tetramethyl-4-piperidinyl)imino]].

[0026] Ultraviolet light absorber: 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

[0027] II. Preparation Process Step 1: Preprocessing stage Surface modification of carbon materials MWCNT and KB were placed in 68% concentrated nitric acid and refluxed at 80°C for 2 hours. After washing with deionized water until pH=7, they were dried in a vacuum drying oven at 80°C for 12 hours.

[0028] Alternative solution: Oxidation with a mixed acid solution of 30% hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:3, at a treatment temperature of 70℃ for 1.5 hours.

[0029] Resin premix Epoxy resin E-51 and polyurethane PU were added to the reactor at a mass ratio of 2:1. The mixing order was as follows: first, polyurethane was added and preheated to 60°C, then epoxy resin was slowly added to avoid local overheating and agglomeration. Heat stabilizer and ultraviolet absorber were added in sequence, and the mixture was mechanically stirred at 60°C for 1 hour (stirring speed 300 rpm) to form a homogeneous premixed resin.

[0030] Step 2: Conductive filler dispersion stage Ultrasonic dispersion The modified MWCNT, KB and PPy were added to the premixed resin in sequence, and the mixture was treated with an ultrasonic cell disruptor at 400W power and 20kHz frequency for 30 minutes (pulse working mode: 10s working / 5s pause, total effective ultrasonic time 25 minutes). The material temperature was controlled to be ≤40℃ during the ultrasonic process.

[0031] High-speed dispersion Transfer to a high-speed disperser and continue stirring at 3000 rpm for 1 hour, during which coupling agent KH-560 and dispersant BYK-110 are added. The barrel temperature is controlled to ≤45℃ by circulating water cooling. After dispersion, the filler particle size distribution is detected by a laser particle size analyzer to ensure that D90≤80μm, forming a conductive resin system with uniformly dispersed filler.

[0032] Step 3: Molding and Processing Stage Compression Curing The mixture is injected into a mold preheated to 120°C (mold size accuracy ±0.02mm), held under pressure of 10MPa, heated to 150°C at a rate of 2°C / min, and cured for 2 hours.

[0033] Post-processing After naturally cooling to 60℃, the material is demolded and a transparent anti-corrosion coating is applied to the surface using an electrostatic spraying process. Coating material: Fluorocarbon resin-based compound, composed of perfluoropolyether modified acrylate and nano-silica in a mass ratio of 95:5.

[0034] Spraying parameters: Spraying voltage 60kV, coating thickness 10-20μm (monitored in real time by film thickness gauge, error ±2μm), curing process is baking at 120℃ for 30 minutes.

[0035] Coating performance: Contact angle ≥110°, weather resistance meets GB / T 1865-2009 standard.

[0036] Final processing The product is cured at 80℃ for 1 hour, then cut, trimmed, and packaged.

[0037] III. Performance Optimization Design Conductive network coordination mechanism Achieving multi-scale conductive pathways through filler gradation design: PPy is used to construct long-range conductive networks; MWCNT fills the gaps in the network; KB forms micro-region conductive channels.

[0038] The synergy of these three factors gives the material a low percolation threshold.

[0039] Lightweight design The density was further controlled by adding 5 wt% hollow glass microspheres (density 0.6 g / cm³), resulting in a final material density ≤ 1.18 g / cm³ while maintaining a surface resistivity of 8.2 × 10⁻⁶. 7 The performance includes Ω and electrostatic decay time ≤0.5s.

[0040] IV. Performance Testing and Verification Basic performance Surface resistivity: 10 6 Ω~10 9 Ω (GB / T 1410-2006); Electrostatic decay time: The time required for the voltage to decay to 10% at 5kV is ≤0.5s (ASTM D257). Mechanical properties: tensile strength ≥50MPa, flexural modulus ≥2000MPa, impact strength ≥40kJ / m² (GB / T1040.2, GB / T 9341, GB / T 1843). Density: ≤1.2g / cm³ (GB / T 1033.1-2008 Method A).

[0041] Environmental adaptability Humid heat aging: After 500 hours of testing at 85℃ and 85% relative humidity, the change in surface resistivity is ≤1 order of magnitude; Xenon lamp aging: After 300 hours of irradiation (wavelength 300-400nm, irradiance 0.51W / m²), the color difference ΔE ≤ 1.5, with no cracking, bubbling or fading. Application verification: 50 takeoff and landing tests were completed under propeller thunderstorm weather (wind speed 12m / s, rainfall 50mm / h). The radar wave reflectivity was normal and there were no abnormal interruptions in flight data.

[0042] This composite material achieves a balance between conductivity, weather resistance, and lightweight through multi-component synergistic design and precision manufacturing process, meeting the long-term use requirements in harsh environments such as aerospace and electronics.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A conductive and weather-resistant composite material, characterized in that: The composite material is composed of the following raw materials by weight percentage composition: The matrix resin is composed of bisphenol A type epoxy resin E-51 and thermoplastic polyurethane elastomer PU in a mass ratio of 2:1, wherein epoxy resin E-51 accounts for 40 wt% and polyurethane PU accounts for 20 wt%. Conductive filler: composed of networked polypyrrole (PPy), carboxylated multi-walled carbon nanotubes (MWCNT), and high-structure conductive carbon black (KB) in a mass ratio of 1.5:1:1, wherein PPy accounts for 15 wt%, MWCNT accounts for 10 wt%, and KB accounts for 10 wt%. Functional additives: composed of hindered amine light stabilizers, benzotriazole ultraviolet absorbers UV-P, silane coupling agents KH-560, and superdispersants BYK-110 in a mass ratio of 1:1:1:2, wherein the heat stabilizer accounts for 1 wt%, the ultraviolet absorber accounts for 1 wt%, the coupling agent accounts for 1 wt%, and the dispersant accounts for 2 wt%.

2. The method for preparing a conductive and weather-resistant composite material according to claim 1, characterized in that: The preparation methods of this composite material include: Step 1, Preprocessing stage: Multi-walled carbon nanotubes (MWCNTs) and conductive carbon black (KB) were placed in concentrated nitric acid with a mass fraction of 68% and refluxed at 80°C for 2 hours. After washing with deionized water until pH=7, they were dried in a vacuum drying oven at 80°C for 12 hours. Epoxy resin E-51 and polyurethane PU were added to a reactor at a mass ratio of 2:1, followed by heat stabilizer and ultraviolet absorber. The mixture was mechanically stirred at 60°C for 1 hour at a stirring speed of 300 rpm to form a homogeneous premixed resin. Step 2, Conductive Filler Dispersion Stage: The modified MWCNT, KB and networked polypyrrole PPy were added to the premixed resin in sequence, and the mixture was treated with an ultrasonic cell disruptor at 400W power and 20kHz frequency for 30 minutes. During the ultrasonic process, the material temperature was controlled to be ≤40℃. Transfer to a high-speed disperser and continue stirring at 3000 rpm for 1 hour. During this time, add coupling agent KH-560 and dispersant BYK-110 to form a conductive resin system with uniformly dispersed filler. Step 3, Molding and Processing Stage: The mixture is injected into a mold preheated to 120°C with a mold dimensional accuracy of ±0.02mm. It is then held under 10MPa pressure and heated to 150°C at a rate of 2°C / min, and cured for 2 hours. After naturally cooling to 60℃, the material is demolded and a transparent anti-corrosion coating is applied to the surface using an electrostatic spraying process. The spraying voltage is 60kV, and the coating thickness is monitored in real time by a film thickness gauge with an error of ±2μm. The final product is cured at 80°C for 1 hour, then cut, trimmed, and packaged.

3. The conductive and weather-resistant composite material according to claim 1, characterized in that: The networked polypyrrole (PPy) is synthesized via a soft template method, specifically as follows: Using sodium dodecylbenzenesulfonate as a template agent, pyrrole monomers were polymerized in an ice bath at 0°C for 12 hours under the action of ammonium persulfate oxidant. After repeated washing with ethanol, the wire diameter was controlled at 20-35 nm to form an interpenetrating three-dimensional conductive network structure. The carboxylated multi-walled carbon nanotubes (MWCNTs) are treated with mixed acid oxidation, with a diameter of 10-20 nm, a length of 5-15 μm, and a surface carboxyl content ≥1.2 wt%; the high-structure conductive carbon black (KB) has a particle size distribution D50 of 30-50 nm and a specific surface area ≥1200 m² / g.

4. The conductive and weather-resistant composite material according to claim 1, characterized in that: The epoxy resin E-51 in the matrix resin has an epoxy value of 0.51 mol / 100g, and the polyurethane PU has a Shore hardness of A85±5. The heat stabilizer in the functional additives is poly[(6-morpholine-s-triazine-2,4-diyl)[2,2,6,6-tetramethyl-4-piperidinyl)imino]], the ultraviolet absorber is 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, the coupling agent KH-560 has the molecular formula C9H20O5Si, and the dispersant BYK-110 is a copolymer solution containing acidic groups.

5. The conductive and weather-resistant composite material according to claim 1, characterized in that: The surface resistivity of the composite material is controlled to be 10. 6 Ω~10 11 Ω, tested according to GJB3007 (SJ / T10694) standard; under a 5kV applied voltage, the time required for electrostatic decay to reach 10% is ≤0.5s, the test method refers to ASTM D257; the material density is ≤1.2g / cm³, determined according to GB / T 1033.1-2008 method A; tensile strength ≥50MPa, flexural modulus ≥2000MPa, impact strength ≥40kJ / m², respectively performed according to GB / T1040.2, GB / T 9341, and GB / T 1843 standards.

6. The conductive and weather-resistant composite material according to claim 1, characterized in that: The composite material is coated with a transparent anti-corrosion coating with a thickness of 10-20 μm. The coating material is a fluorocarbon resin-based compound, specifically composed of perfluoropolyether modified acrylate and nano-silica in a mass ratio of 95:

5. The curing process is baking at 120℃ for 30 minutes. The coating contact angle is ≥110°, and the weather resistance meets the GB / T 1865-2009 standard.

7. The method for preparing a conductive and weather-resistant composite material according to claim 2, characterized in that: The concentrated nitric acid treatment process in step one can be replaced by a mixed acid oxidation of 30% hydrogen peroxide and concentrated sulfuric acid in a volume ratio of 1:3, with a treatment temperature of 70°C and a time of 1.5 hours. In the preparation of the premixed resin, the mixing order of epoxy resin and polyurethane is as follows: first add polyurethane and preheat to 60°C, then slowly add epoxy resin to avoid local overheating and clumping.

8. The method for preparing a conductive and weather-resistant composite material according to claim 2, characterized in that: In step two, the ultrasonic dispersion adopts a pulse working mode, with 10 seconds of operation and 5 seconds of pause, for a total effective ultrasonic time of 25 minutes. During the high-speed dispersion process, the temperature of the material barrel is controlled to be ≤45℃ by circulating water cooling. After dispersion, a laser particle size analyzer is used to detect the particle size distribution of the filler to ensure that D90≤80μm.

9. The method for preparing a conductive and weather-resistant composite material according to claim 2, characterized in that: The composite material, through filler gradation design, enables PPy to construct a long-range conductive network, MWCNT to fill the network gaps, and KB to form micro-area conductive channels. These three elements work synergistically to achieve a low percolation threshold. The material density is further controlled by adding 5wt% hollow glass microspheres, resulting in a final density ≤1.18 g / cm³, while maintaining a surface resistivity of 8.2 × 10⁻⁶. 7 The performance includes Ω and electrostatic decay time ≤0.5s.

10. The method for preparing a conductive and weather-resistant composite material according to claim 2, characterized in that: The composite material was verified by a third-party testing agency. After 500 hours of damp heat aging test at 85℃ and 85% relative humidity, the surface resistivity change was ≤1 order of magnitude. After 300 hours of xenon lamp aging, the material color difference ΔE was ≤1.5, and there were no visible cracks, blistering or fading. In the propeller application verification, 50 take-off and landing tests were completed in thunderstorm weather, the radar wave reflectivity was normal, and the flight data was not abnormally interrupted.

Images