Carbon fiber reinforced polypropylene composite material for unmanned aerial vehicle and preparation method thereof

Abstract

The invention discloses a carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles and a preparation method thereof, and belongs to the technical field of composite materials, the carbon fiber reinforced polypropylene composite material comprises the following raw materials by weight: 100 parts of polypropylene resin, 8-12 parts of a compatilizer, 15-20 parts of amino MOFs modified carbon fiber, 3-5 parts of a thiourea hyperbranched cross-linking agent, and 0.3-0.5 part of an initiator; the amino MOFs modified carbon fiber is obtained by loading amino MOFs on the surface of continuous carbon fiber through electrochemical deposition and then shearing, and according to the composite material, through the synergistic effect of the amino MOFs modified carbon fiber and a thiourea hyperbranched cross-linking agent, an ion coordination-covalent cross-linking dual-interface enhancement mechanism is constructed, efficient stress transfer is achieved, and the mechanical property is remarkably improved; meanwhile, the two generate a gas phase dilution-condensed phase charring synergistic flame-retardant effect in combustion, so that the material is endowed with excellent flame retardance, and the problems of poor interface bonding and flammability are comprehensively solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of composite materials, and particularly relates to a carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles and a preparation method thereof. BACKGROUND

[0002] An unmanned aerial vehicle (hereinafter referred to as "unmanned aerial vehicle") is a pilotless aircraft that is controlled by using radio remote control equipment and self-provided program control devices. In order to meet the harsh requirements of modern unmanned aerial vehicles for low cost, lightweight, high stealth, long flight time and high storage life, the selection of structural materials is crucial. Composite materials have become the first choice of materials for unmanned aerial vehicle structures due to their high specific strength, large specific modulus, strong designability, good fatigue resistance and excellent damping and shock absorption characteristics, and are widely used in key parts such as fuselage, wings, tail, rudder and landing gear. A large number of application practices have proved that composite materials can achieve a weight reduction effect of 20-30% for unmanned aerial vehicle structures.

[0003] Among many composite material systems, thermoplastic carbon fiber composite materials (TPC) are becoming the material cornerstone for promoting the large-scale development of low-altitude economic equipment such as unmanned aerial vehicles due to their high production efficiency, good impact resistance and recyclability. Among them, TPC with polypropylene (PP) as the matrix has a wide range of raw material sources, low cost, excellent chemical corrosion resistance and impact resistance, and is considered as a promising material solution for large-scale and low-cost manufacturing of unmanned aerial vehicles.

[0004] However, the surface of carbon fiber is smooth and lacks polar groups, and the wetting ability between the carbon fiber and the resin matrix is poor, which leads to low interfacial adhesion strength between the carbon fiber and the matrix, thereby affecting the performance improvement of the composite material. At present, carbon fiber surface modification is an effective method to improve the interfacial compatibility between the fiber and the matrix.

[0005] Common carbon fiber modification methods include strong acid oxidation and sizing agent treatment. The strong acid oxidation can increase the surface roughness of the fiber, but it is easy to cause fiber damage. The sizing agent treatment generally uses epoxy resin sizing agent, but the interfacial bonding force between the carbon fiber treated by the sizing agent and the PP matrix is poor. Fiber damage and poor bonding performance will both lead to poor mechanical properties of the composite material. Therefore, it is a technical problem to be solved at present to provide a carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles with high mechanical strength. SUMMARY

[0006] One of the purposes of the present application is to provide a carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles, which solves the problem of poor mechanical properties of the current carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles.

[0007] The second purpose of the present application is to provide a preparation method of the above-mentioned carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles.

[0008] The object of the present application can be achieved by the following technical solutions: A carbon fiber reinforced polypropylene composite material for a UAV, raw materials of which include polypropylene resin 100 parts, compatibility agent 8-12 parts, amino MOFs modified carbon fiber 15-20 parts, thiourea hyperbranched crosslinking agent 3-5 parts, and initiator 0.3-0.5 parts.

[0009] The amino MOFs modified carbon fiber is obtained by shearing after loading amino MOFs on the surface of continuous carbon fiber through electrochemical deposition. Compared with chemical deposition method, electrochemical deposition does not need to perform pre-etching treatment on the carbon fiber, which is conducive to protecting the integrity of the carbon fiber matrix structure. In addition, metal organic framework (MOFs) has the characteristics of porous structure and high specific surface area. Introducing amino MOFs on the surface of MOFs not only improves the roughness of the surface of the carbon fiber but also introduces active amino groups, both of which are conducive to improving the binding property of the carbon fiber and the polypropylene matrix.

[0010] Further, the preparation steps of the amino MOF modified carbon fiber are as follows: The pretreated continuous carbon fiber is uniformly wound on a platinum sheet electrode as a working electrode, the platinum sheet electrode is used as a counter electrode, an electrolyte is prepared by using a metal source, an organic ligand, triethylamine hydrochloride and N,N-dimethylformamide, the working electrode and the counter electrode are inserted into the electrolyte to form a two-electrode system, the electrodes are connected with an electrochemical workstation, a constant potential of-2V is applied at room temperature for chemical deposition for 10-15min, after the deposition is completed, the carbon fiber on the surface of the working electrode is taken out and sheared to a length of 1-9mm to obtain the amino MOF modified carbon fiber.

[0011] Further, the amount ratio of the metal source, the organic ligand, the triethylamine hydrochloride and the N,N-dimethylformamide in the electrolyte is 0.05-0.15mol:0.05-0.15mol:0.03mol:1L, and the molar ratio of the metal source and the organic ligand is controlled to be 1:1, wherein the triethylamine hydrochloride can prevent the metal ions from being reduced to metal elements under negative potential.

[0012] Further, the metal source is copper nitrate and / or zinc nitrate.

[0013] Further, the organic ligand is 2-amino terephthalic acid.

[0014] Further, the pretreated continuous carbon fiber is obtained by the following steps: The continuous carbon fiber is soaked in acetone for 48h, then taken out, washed with acetone and dried, and vacuum dried.

[0015] Further, the continuous carbon fiber is T300 high-strength polyacrylonitrile-based carbon fiber, and the density is 1.76 g / cm 3 , and the single fiber diameter is 6-8 μm.

[0016] The raw materials for preparing the thiourea hyperbranched crosslinking agent include melamine, p-phenylene diisothiocyanate and alkenyl succinic anhydride, wherein the p-phenylene diisothiocyanate and the melamine are an A2 type monomer and a B3 type monomer, respectively, for preparing the hyperbranched polymer, and the alkenyl succinic anhydride is an end-capping agent for the hyperbranched polymer.

[0017] Further, the alkenyl succinic anhydride is at least one of allyl succinic anhydride, octenyl succinic anhydride, dodecenyl succinic anhydride and octadecenyl succinic anhydride.

[0018] Further, the preparation step of the thiourea hyperbranched crosslinking agent is as follows: The melamine and the p-phenylene diisothiocyanate are added into N,N-dimethylformamide, stirred uniformly, stirred for 30 min at 0-5 ℃ under nitrogen protection, stirred for 6-12 h at 60-80 ℃, after the reaction is completed, cooled to room temperature, added with triethylamine, stirred uniformly, then added dropwise with a solution of the alkenyl succinic anhydride in N,N-dimethylformamide, after the dropwise addition is completed, reacted for 4-6 h at 40-60 ℃, after the reaction is completed, removed with N,N-dimethylformamide by distillation under reduced pressure, washed with deionized water after the distillation product is dried, to obtain the thiourea hyperbranched crosslinking agent.

[0019] Further, the molar ratio of the melamine, the p-phenylene diisothiocyanate, the triethylamine and the alkenyl succinic anhydride is 1:1:0.2-0.3:1.2-1.5, the p-phenylene diisothiocyanate and the melamine are used as the A2 type monomer and the B3 type monomer, respectively, to obtain an amino-terminated hyperbranched polymer containing a rich thiourea structure through the reaction between the isothiocyanate and the amino group, then the amino-terminated hyperbranched polymer is end-capped by using the alkenyl succinic anhydride through the reaction between the amino group and the anhydride group, to obtain the thiourea hyperbranched crosslinking agent carrying the thiourea structure and the unsaturated carbon chain.

[0020] Further, the initiator is dicumyl peroxide and / or benzoyl peroxide.

[0021] Further, the compatilizer is at least one of maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-octene and maleic anhydride grafted ethylene-vinyl acetate.

[0022] Further, the carbon fiber reinforced polypropylene composite material for the unmanned aerial vehicle further includes 0.2-0.5 parts by weight of an antioxidant and 0.2-0.5 parts by weight of a lubricant.

[0023] Further, the antioxidant is composed of antioxidant 168 and antioxidant 1010 according to a mass ratio of 1:1.

[0024] Further, the lubricant is ethylene bis-stearamide.

[0025] The preparation method of the carbon fiber reinforced polypropylene composite material for the unmanned aerial vehicle comprises the following steps: After the raw materials except the amino MOF modified carbon fiber in the raw materials are uniformly mixed, the amino MOF modified carbon fiber is added from the fiber inlet of the twin-screw extruder, and then extrusion granulation is performed to obtain the carbon fiber reinforced polypropylene composite material for the unmanned aerial vehicle.

[0026] Further, the temperature of the first to sixth zones of the twin-screw extruder is set as follows: the first zone is 190-200 DEG C, the second zone is 195-205 DEG C, the third zone is 205-210 DEG C, the fourth zone is 210-215 DEG C, the fifth zone is 215-220 DEG C, and the sixth zone is 215-220 DEG C, and the temperature of the die head is 215-220 DEG C.

[0027] The present application has the following advantages: 1. In view of the poor bonding between carbon fibers and polypropylene matrix, the amino MOFs are loaded on the surface of continuous carbon fibers by an electrochemical deposition method, and then the amino MOFs modified carbon fiber is prepared by shearing, and the amino MOFs modified carbon fiber is introduced into the polypropylene system, which increases the surface roughness of the carbon fiber, realizes the mechanical interlocking of the carbon fiber and the matrix, and forms a firm amide bond by the reaction between the amino groups on the surface of the MOFs and the anhydride groups in the compatibilizer, thereby preliminarily enhancing the interfacial bonding force between the carbon fiber and the polypropylene; The rich thiourea groups in the thiourea hyperbranched crosslinking agent can form ionic coordination bonds with the metal ions on the surface of the amino MOFs modified carbon fiber, and the unsaturated carbon chains at the ends of the crosslinking agent are grafted onto the polypropylene segment under the action of the initiator to form a covalent crosslinking network, and the dual action of ionic coordination-covalent crosslinking builds a strong and tough transition interface layer between the carbon fiber and the matrix, realizes efficient transmission of stress load, and thus greatly improves the tensile strength of the composite material; in addition, the three-dimensional cavity structure of the thiourea hyperbranched crosslinking agent can deform under external force impact, effectively absorbing and dispersing energy, thereby significantly improving the impact toughness of the composite material. In summary, the present application improves the mechanical properties of the carbon fiber polypropylene composite material through the synergistic effect of multiple mechanisms.

[0028] 2.In the present application, the amino MOF modified carbon fiber can preferentially catalyze the formation of a dense and stable carbon layer at high temperature, which covers the surface of the material, effectively insulates heat and combustible gas, and plays a "barrier" protection effect. The thiourea hyperbranched crosslinking agent decomposes at the initial stage of combustion, which may release non-combustible gas containing nitrogen and sulfur to dilute the concentration of combustible material. At the same time, the hyperbranched structure helps to promote the carbonization of MOFs and produces a synergistic effect with the carbon layer, together building a more complete and more solid intumescent carbon layer. Through the synergistic flame retardant path of "gas phase dilution-coagulation phase carbonization", the flame propagation is significantly delayed and the dripping phenomenon is inhibited, which endows the composite material with excellent flame retardant performance. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In the following examples and comparative examples, the polypropylene resin is homopolymer PP Z30S from Maoming Branch of China Petroleum Chemical Co., Ltd., the maleic anhydride grafted polypropylene is PC-1B with a grafting rate of 0.7-1.0% from Foshan Baimen High Polymer Material Co., Ltd., and the continuous carbon fiber is T300 high-strength polyacrylonitrile-based carbon fiber with a density of 1.76 g / cm 3 , and a single fiber diameter of 6-8 μm. The following will be specifically described in combination with the examples.

[0031] Preparation Example 1

[0032] An amino MOF modified carbon fiber is prepared by the following steps: The pretreated continuous carbon fiber is uniformly wound on a platinum electrode as a working electrode, the platinum electrode is used as a counter electrode, copper nitrate, 2-amino terephthalic acid, triethylamine hydrochloride and N,N-dimethylformamide are uniformly mixed as an electrolyte according to 0.05 mol: 0.05 mol: 0.03 mol: 1 L, the working electrode and the counter electrode are inserted into the electrolyte to form a two-electrode system, the electrodes are connected with an electrochemical workstation, a constant potential of-2 V is applied at room temperature for 10 min of chemical deposition, and then the carbon fiber on the surface of the working electrode is taken out and cut to a length of 1-9 mm to obtain the amino MOF modified carbon fiber.

[0033] The pretreated continuous carbon fiber is obtained by the following steps: The continuous carbon fiber is soaked in acetone for 48 h, then taken out, washed with acetone and dried, and vacuum dried.

[0034] Preparation Example 2

[0035] An amino MOF modified carbon fiber, the preparation steps are as follows: The pretreated continuous carbon fiber is uniformly wound on a platinum sheet electrode as a working electrode, the platinum sheet electrode is used as a counter electrode, copper nitrate, 2-amino terephthalic acid, triethylamine hydrochloride and N,N-dimethylformamide are uniformly mixed as 0.1 mol: 0.1 mol: 0.03 mol: 1 L as an electrolyte, the working electrode and the counter electrode are inserted into the electrolyte to form a two-electrode system, the electrodes are connected with an electrochemical workstation, a constant potential of-2 V is applied at room temperature for chemical deposition for 12 min, after the deposition is completed, the carbon fiber on the surface of the working electrode is taken out and cut to a length of 1-9 mm to obtain an amino MOF modified carbon fiber.

[0036] The preparation steps of the pretreated continuous carbon fiber are the same as those in Preparation Example 1.

[0037] Preparation Example 3

[0038] An amino MOF modified carbon fiber, the preparation steps are as follows: The pretreated continuous carbon fiber is uniformly wound on a platinum sheet electrode as a working electrode, the platinum sheet electrode is used as a counter electrode, copper nitrate, 2-amino terephthalic acid, triethylamine hydrochloride and N,N-dimethylformamide are uniformly mixed as 0.1 mol: 0.1 mol: 0.03 mol: 1 L as an electrolyte, the working electrode and the counter electrode are inserted into the electrolyte to form a two-electrode system, the electrodes are connected with an electrochemical workstation, a constant potential of-2 V is applied at room temperature for chemical deposition for 12 min, after the deposition is completed, the carbon fiber on the surface of the working electrode is taken out and cut to a length of 1-9 mm to obtain an amino MOF modified carbon fiber.

[0039] The preparation steps of the pretreated continuous carbon fiber are the same as those in Preparation Example 1.

[0040] Comparative Example 1

[0041] A MOF modified carbon fiber, compared with Preparation Example 1, the only difference is that the 2-amino terephthalic acid in Preparation Example 1 is replaced by an equal molar amount of terephthalic acid.

[0042] Comparative Example 2

[0043] A MOF modified carbon fiber, compared with Preparation Example 2, the only difference is that the 2-amino terephthalic acid in Preparation Example 2 is replaced by an equal molar amount of terephthalic acid.

[0044] Comparative Example 3

[0045] A MOF modified carbon fiber, compared with Preparation Example 3, the only difference is that the 2-amino terephthalic acid in Preparation Example 3 is replaced by an equal molar amount of terephthalic acid.

[0046] Example 1

[0047] A carbon fiber reinforced polypropylene composite material for a drone, raw materials of which include, by weight, 100 parts of polypropylene resin, 8 parts of maleic anhydride grafted polypropylene, 15 parts of the amino MOFs modified carbon fiber of Preparation Example 1, 3 parts of a thiourea hyperbranched crosslinking agent, 0.3 parts of dicumyl peroxide, 0.2 parts of an antioxidant, and 0.2 parts of ethylene bis-stearamide.

[0048] The preparation steps of the thiourea hyperbranched crosslinking agent are as follows: 0.1 mol of melamine and 0.1 mol of p-phenylene diisothiocyanate were added to 300 mL of N,N-dimethylformamide, stirred uniformly, stirred for 30 min at 0°C under nitrogen protection, stirred for 6 h at 60°C, after the reaction was completed, the temperature was lowered to room temperature, 0.02 mol of triethylamine was added and stirred uniformly, then a mixed solution composed of 0.12 mol of allyl succinic anhydride and 300 mL of N,N-dimethylformamide was added dropwise, after the dropwise addition was completed, the reaction was carried out at 40°C for 4 h, after the reaction was completed, N,N-dimethylformamide was removed by distillation under reduced pressure, the distillation product was washed with deionized water and then dried to obtain the thiourea hyperbranched crosslinking agent.

[0049] The antioxidant is composed of antioxidant 168 and antioxidant 1010 in a mass ratio of 1:1.

[0050] The preparation method of the above-mentioned carbon fiber reinforced polypropylene composite material for a drone is as follows: After the polypropylene, the compatibilizer, the thiourea hyperbranched crosslinking agent, the dicumyl peroxide, the antioxidant, and the ethylene bis-stearamide were uniformly mixed, they were added to a twin-screw extruder, the amino MOF modified carbon fiber was added from the fiber inlet of the twin-screw extruder, and then extrusion granulation was performed to obtain the carbon fiber reinforced polypropylene composite material for a drone.

[0051] The temperature settings of the first to sixth zones of the twin-screw extruder were as follows: 190°C for the first zone, 195°C for the second zone, 205°C for the third zone, 210°C for the fourth zone, 215°C for the fifth zone, and 215°C for the sixth zone, and the temperature of the die head was 215°C.

[0052] Example 2

[0053] A carbon fiber reinforced polypropylene composite material for a drone, raw materials of which include, by weight, 100 parts of polypropylene resin, 10 parts of maleic anhydride grafted polypropylene, 18 parts of the amino MOFs modified carbon fiber of Preparation Example 1, 4 parts of a thiourea hyperbranched crosslinking agent, 0.4 parts of dicumyl peroxide, 0.4 parts of an antioxidant, and 0.4 parts of ethylene bis-stearamide.

[0054] The preparation steps of the thiourea hyperbranched crosslinking agent are as follows: 0.1 mol of melamine and 0.1 mol of p-phenylene diisothiocyanate were added into 400 mL of N,N-dimethylformamide, stirred uniformly, stirred for 30 min at 3 DEG C under nitrogen protection, stirred for 8 h at 70 DEG C, after the reaction was completed, cooled to room temperature, 0.02 mol of triethylamine was added and stirred uniformly, then a mixed solution composed of 0.135 mol of octenyl succinic anhydride and 300 mL of N,N-dimethylformamide was added dropwise, after the dropwise addition was completed, reaction was carried out for 5 h at 50 DEG C, after the reaction was completed, N,N-dimethylformamide was removed by distillation under reduced pressure, the distillation product was washed with deionized water and dried, thereby obtaining a thiourea hyperbranched crosslinking agent.

[0055] The antioxidant was composed of antioxidant 168 and antioxidant 1010 at a mass ratio of 1:1.

[0056] The preparation method of the carbon fiber reinforced polypropylene composite material for the unmanned aerial vehicle is as follows: The polypropylene, the compatibilizer, the thiourea hyperbranched crosslinking agent, the dicumyl peroxide, the antioxidant and the ethylene bis-stearamide were uniformly mixed, then were added into a twin-screw extruder, the amino MOF modified carbon fiber was added from the fiber inlet of the twin-screw extruder, and then was subjected to extrusion granulation, thereby obtaining the carbon fiber reinforced polypropylene composite material for the unmanned aerial vehicle.

[0057] The temperature settings of the first to sixth zones of the twin-screw extruder were as follows: 195 DEG C for the first zone, 200 DEG C for the second zone, 205 DEG C for the third zone, 210 DEG C for the fourth zone, 215 DEG C for the fifth zone, and 215 DEG C for the sixth zone, and the temperature of the die head was 215 DEG C.

[0058] Example 3

[0059] A carbon fiber reinforced polypropylene composite material for an unmanned aerial vehicle, raw materials of which include, by weight, 100 parts of polypropylene resin, 12 parts of maleic anhydride grafted polypropylene, 20 parts of the amino MOF modified carbon fiber prepared in Preparation Example 1, 5 parts of a thiourea hyperbranched crosslinking agent, 0.5 parts of dicumyl peroxide, 0.5 parts of an antioxidant, and 0.5 parts of ethylene bis-stearamide.

[0060] The preparation steps of the thiourea hyperbranched crosslinking agent are as follows: 0.1 mol of melamine and 0.1 mol of p-phenylene diisothiocyanate were added into 500 mL of N,N-dimethylformamide, stirred uniformly, stirred for 30 min at 5 DEG C under nitrogen protection, stirred for 12 h at 80 DEG C, after the reaction was completed, cooled to room temperature, 0.03 mol of triethylamine was added and stirred uniformly, then a mixed solution composed of 0.15 mol of dodecenyl succinic anhydride and 300 mL of N,N-dimethylformamide was added dropwise, after the dropwise addition was completed, reaction was carried out for 6 h at 60 DEG C, after the reaction was completed, N,N-dimethylformamide was removed by distillation under reduced pressure, the distillation product was washed with deionized water and dried, thereby obtaining a thiourea hyperbranched crosslinking agent.

[0061] The antioxidant is composed of antioxidant 168 and antioxidant 1010 at a mass ratio of 1:1.

[0062] The preparation method of the carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles is as follows: The polypropylene, the compatibilizer, the thiourea hyperbranched crosslinking agent, the dicumyl peroxide, the antioxidant, and the ethylene bis-stearamide are uniformly mixed, and then added into a twin-screw extruder, the amino MOF modified carbon fiber is added from the fiber inlet of the twin-screw extruder, and then extrusion granulation is performed to obtain the carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles.

[0063] The temperature settings of the first to sixth zones of the twin-screw extruder are as follows: 200 DEG C for the first zone, 205 DEG C for the second zone, 210 DEG C for the third zone, 215 DEG C for the fourth zone, 220 DEG C for the fifth zone, and 220 DEG C for the sixth zone, and the temperature of the die head is 220 DEG C.

[0064] Example 4

[0065] A carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles, compared with example 1, the difference is only in the replacement of the amino MOFs modified carbon fiber in example 1 with the product obtained in preparation example 2.

[0066] Example 5

[0067] A carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles, compared with example 1, the difference is only in the replacement of the amino MOFs modified carbon fiber in example 1 with the product obtained in preparation example 3.

[0068] Example 6

[0069] A carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles, compared with example 2, the difference is only in the replacement of the amino MOFs modified carbon fiber in example 2 with the product obtained in preparation example 2.

[0070] Example 7

[0071] A carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles, compared with example 2, the difference is only in the replacement of the amino MOFs modified carbon fiber in example 2 with the product obtained in preparation example 3.

[0072] Example 8

[0073] A carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles, compared with example 3, the difference is only in the replacement of the amino MOFs modified carbon fiber in example 1 with the product obtained in preparation example 2.

[0074] Example 9

[0075] A carbon fiber reinforced polypropylene composite material for a drone, which is different from Example 1 only in that the amino MOFs modified carbon fiber in Example 1 is replaced with the product obtained in Preparation Example 3 in the same weight parts.

[0076] Comparative Example 1

[0077] A carbon fiber reinforced polypropylene composite material for a drone, which is different from Example 1 only in that the amino MOFs modified carbon fiber in Example 1 is replaced with the product obtained in Comparative Example 1 in the same weight parts.

[0078] Comparative Example 2

[0079] A carbon fiber reinforced polypropylene composite material for a drone, which is different from Example 1 only in that the amino MOFs modified carbon fiber in Example 1 is replaced with the product obtained in Comparative Example 2 in the same weight parts.

[0080] Comparative Example 3

[0081] A carbon fiber reinforced polypropylene composite material for a drone, which is different from Example 1 only in that the amino MOFs modified carbon fiber in Example 1 is replaced with the product obtained in Comparative Example 3 in the same weight parts.

[0082] Comparative Example 4

[0083] A carbon fiber reinforced polypropylene composite material for a drone, which is different from Example 1 only in that the preparation step of the thiourea hyperbranched crosslinking agent in the present comparative example is as follows: 0.1 mol of melamine and 0.1 mol of p-phenylene diisothiocyanate were added to 300 mL of N,N-dimethylformamide, stirred uniformly, stirred at 0°C for 30 min under nitrogen protection, stirred at 60°C for 6 h, after the reaction was completed, N,N-dimethylformamide was removed by distillation under reduced pressure, and the distillation product was washed with deionized water and dried to obtain a thiourea hyperbranched crosslinking agent.

[0084] Comparative Example 5

[0085] A carbon fiber reinforced polypropylene composite material for a drone, which is different from Example 1 only in that the maleic anhydride grafted polypropylene in Example 1 is removed.

[0086] Comparative Example 6

[0087] A carbon fiber reinforced polypropylene composite material for a drone, which is different from Example 1 only in that the thiourea hyperbranched crosslinking agent in Example 1 is replaced with maleic anhydride grafted polypropylene in the same weight parts.

[0088] The obtained drone carbon fiber reinforced polypropylene composites of Example 1-Example 9 and Comparative Example 1-Comparative Example 6 were added into an injection molding machine for injection molding, the injection molding temperature was 200℃, to obtain test samples, and the performance test was carried out, and the test items and test standards were as follows: Mechanical properties: tensile strength was tested according to GB / T 2567-2021; notched impact strength was tested according to GB / T 1043.1-2008; LOI test: tested according to GB / T 2406.2-2009, sample size was 50mmx8mmx5mm.

[0089] The test results are shown in Table 1: Table 1

[0090] As can be seen from Table 1, the tensile strength of the drone carbon fiber reinforced polypropylene composites obtained in Example 1-Example 9 is 106-116.1MPa, the impact strength is 12.7-14.8kJ / m 2 , and the oxygen index is 30.7-32.5%, compared with Comparative Example 1-Comparative Example 6, the comprehensive performance is better.

[0091] It should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the term "includes", "contains" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0092] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A carbon fiber reinforced polypropylene composite material for a drone, characterized by, The raw materials include, by weight, 100 parts of polypropylene resin, 8-12 parts of compatibilizer, 15-20 parts of amino MOFs modified carbon fiber, 3-5 parts of thiourea hyperbranched crosslinking agent, and 0.3-0.5 parts of initiator. The amino MOFs modified carbon fiber is obtained by shearing after loading amino MOFs on the surface of continuous carbon fiber through electrochemical deposition. 2.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 1, characterized in that, The preparation steps of the amino MOF modified carbon fiber are as follows: The pretreated continuous carbon fiber is uniformly wound on a platinum sheet electrode as a working electrode, and the platinum sheet electrode is used as a counter electrode. An electrolyte is prepared from a metal source, an organic ligand, triethylamine hydrochloride and N,N-dimethylformamide. The working electrode and the counter electrode are inserted into the electrolyte to form a two-electrode system. The electrodes are connected to an electrochemical workstation, and a constant potential of-2V is applied at room temperature for 10-15min of chemical deposition. After deposition, the carbon fiber on the surface of the working electrode is taken out and sheared to a length of 1-9mm to obtain the amino MOF modified carbon fiber. 3.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 2, characterized in that, The dosage ratio of the metal source, the organic ligand, triethylamine hydrochloride and N,N-dimethylformamide in the electrolyte is 0.05-0.15mol:0.05-0.15mol:0.03mol:1L, and the molar ratio of the metal source and the organic ligand is controlled to be 1:

1. 4.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 2, characterized in that, The metal source is copper nitrate and / or zinc nitrate, and the organic ligand is 2-amino terephthalic acid. 5.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 1, wherein, The raw materials for preparing the thiourea hyperbranched crosslinking agent include melamine, p-phenylene diisothiocyanate and alkenyl succinic anhydride. 6.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 5, characterized in that, The alkenyl succinic anhydride is at least one of allyl succinic anhydride, octenyl succinic anhydride, dodecenyl succinic anhydride and octadecenyl succinic anhydride. 7.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 1 or 5, characterized in that, The preparation steps of the thiourea hyperbranched crosslinking agent are as follows: Melamine and p-phenylene diisothiocyanate are added to N,N-dimethylformamide and stirred uniformly. Under nitrogen protection, stirring is carried out at 0-5℃ for 30min, and at 60-80℃ for 6-12h of reaction. After the reaction is completed, the temperature is lowered to room temperature. After triethylamine is added and stirred uniformly, the N,N-dimethylformamide solution of alkenyl succinic anhydride is added dropwise. After the dropwise addition is completed, the reaction is carried out at 40-60℃ for 4-6h. After the reaction is completed, N,N-dimethylformamide is removed by distillation under reduced pressure. The distillation product is washed with deionized water and dried to obtain the thiourea hyperbranched crosslinking agent. 8.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 7, characterized in that, The molar ratio of melamine, p-phenylene diisothiocyanate, triethylamine and alkenyl succinic anhydride is 1:1:0.2-0.3:1.2-1.

5. 9.The carbon fiber reinforced polypropylene composite material for a UAV according to claim 1, wherein, The initiator is dicumyl peroxide and / or benzoyl peroxide, and the compatibilizer is at least one of maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene-octene and maleic anhydride grafted ethylene-vinyl acetate.

10. A method for preparing a carbon fiber reinforced polypropylene composite material for a drone, characterized by, The method for preparing the carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles according to any one of claims 1-9 comprises the following steps: The raw materials except for the amino MOF modified carbon fiber are uniformly mixed and then added to a double-screw extruder. The amino MOF modified carbon fiber is added from the fiber inlet of the double-screw extruder. After extrusion granulation, the carbon fiber reinforced polypropylene composite material for unmanned aerial vehicles is obtained.

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