Polyamide composite material, method for producing same, and use thereof
By combining polyborosiloxane-modified ammonium polyphosphate with surface-modified vinyl borate containing phosphorus boehmite, the problems of flame retardancy and weather resistance of polyamide composites in new energy charging facilities were solved, and polyamide composites with high CTI and high weather resistance were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGZHOU HUASU NEW MATERIALS CO LTD
- Filing Date
- 2025-09-29
- Publication Date
- 2026-06-12
AI Technical Summary
Existing polyamide composite materials cannot simultaneously meet the requirements of high electrical insulation, high flame retardancy, and high weather resistance in new energy charging facilities. In particular, the GWFI value and CTI value cannot meet the performance standards of new energy charging connectors.
Phosphorus-containing boehmite modified with polyborosiloxane and surface-modified vinyl borate ester was used as modified halogen-free flame retardants. By compounding, the flame retardant properties and compatibility of polyamide composites were improved, free carbon generation was avoided, and weather resistance was enhanced.
While achieving glow wire performance at 960℃ and V0 flame retardant performance, the polyamide composite material also has a CTI value of over 700V and excellent weather resistance (ΔE≤3.3), meeting the high-performance requirements of new energy charging facilities.
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Figure CN121045822B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polyamide composite material technology, specifically relating to a polyamide composite material, its preparation method, and its application. Background Technology
[0002] Currently, the development of new energy vehicles is rapid, and the number of new energy vehicle charging facilities is also gradually increasing. The charging connectors in new energy charging facilities, including plugs and sockets, need to have excellent electrical insulation (CTI>600V), flame retardancy (V-0 / 1.5mm, GWFI: 960℃) and weather resistance because they are directly connected to the wires.
[0003] Polyamide is a common engineering plastic, and PA66, also known as Nylon 66, possesses excellent mechanical properties, heat resistance, electrical insulation, abrasion resistance, and corrosion resistance, making it a promising candidate for charging connectors in new energy charging infrastructure. However, while pure PA66 can achieve a CTI value of 600V, adding flame retardants or fillers can cause its CTI value to decrease, failing to meet the performance requirements of charging connectors in new energy charging infrastructure.
[0004] Chinese Patent Publication No. CN 118165507 A discloses a polyamide composite material, comprising the following components by weight: 60-80 parts polyamide resin; 20-30 parts MCA flame retardant; 110 parts vinyl copolymer containing acidic groups; and 0-1.0 parts other additives; wherein the electrical conductivity of the MCA flame retardant is ≤16μS / cm. This technical solution, by selecting an MCA flame retardant with specific electrical conductivity, rationally controlling the content of the MCA flame retardant, and using the vinyl copolymer containing acidic groups in combination, can achieve good flame retardancy and a high tracking index. Chinese Patent Publication No. CN 120310246 A discloses a high-performance, high-tracking-index flame-retardant reinforced nylon material and its preparation method. The material comprises the following components by weight: 50 parts polyamide PA664, 30-35 parts modified glass fiber, 1-3 parts toughening agent, 10-15 parts flame retardant, 0.2-0.4 parts antioxidant, 0.1-1 part nucleating agent, 0.2-0.4 parts lubricant, 1-3 parts hydrolysis resistant agent, and 1-3 parts CTI modifier. This technical solution improves the flame retardant properties and electrical insulation of nylon materials by optimizing the types and proportions of raw materials.
[0005] Although the polyamide composite material of the above technical solution has a CIT value >600V, reaching the V-0 flame retardant rating, its GWFI value can only reach 850℃.
[0006] To meet the application requirements of charging connectors in the aforementioned new energy charging facilities, there is an urgent need to develop a polyamide composite material that combines high electrical insulation, high flame retardancy, and high weather resistance, which is of great significance to the technological development of the new energy vehicle industry. Summary of the Invention
[0007] In view of this, one object of the present invention is to provide a polyamide composite material, its preparation method and application. The present invention creatively prepares polyborosiloxane-modified ammonium polyphosphate and surface-modified vinyl borate-containing phosphorus boehmite as modified halogen-free flame retardants, thereby achieving high glow wire performance, high flame retardancy, high CTI and weather resistance of the polyamide composite material.
[0008] Another object of the present invention is to provide a method for preparing polyamide composite materials.
[0009] Another objective of this invention is to provide an application of polyamide composite materials in new energy charging facilities.
[0010] To achieve the above objectives, the first aspect of the present invention provides a polyamide composite material comprising the following raw materials in parts by weight: 50-70 parts of PA66, 5-10 parts of modified halogen-free flame retardant, 20-40 parts of glass fiber, 0.1-1 parts of antioxidant, and 0.1-1 parts of lubricant.
[0011] In some preferred embodiments, the relative viscosity of PA66 is 2.62-2.72.
[0012] Preferably, the PA66 can be selected from at least one of Shenma PA66 EPR27, Shenma PA66 EPR27T03, Huafeng EP158 and Huafeng EP158L.
[0013] In some preferred embodiments, the modified halogen-free flame retardant comprises polyborosiloxane-modified ammonium polyphosphate and phosphorus-containing boehmite with surface-modified vinyl borate.
[0014] Preferably, the mass ratio of the polyborosiloxane-modified ammonium polyphosphate to the phosphorus-containing boehmite with surface-modified vinyl borate is 1-2:1-2.
[0015] In some preferred embodiments, the method for preparing the polyborosiloxane-modified ammonium polyphosphate includes the following steps:
[0016] Boric acid, phenylsiloxane, vinylsiloxane A, and aqueous ethanol solution A are mixed, the pH is adjusted, the reaction is initiated, aminosiloxane is added, the reaction continues, and the mixture is distilled under reduced pressure to obtain polyborosiloxane; polyborosiloxane and ammonium polyphosphate are mixed, stirred, and dried to obtain the final product.
[0017] Preferably, the phenylsiloxane is selected from at least one of phenyltrimethoxysilane, phenyltriethoxysilane, methylphenyldimethoxysilane, and diphenyldimethoxysilane.
[0018] Preferably, the vinylsiloxane A is selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri-(2-methoxyethoxy)-silane.
[0019] Preferably, the mass concentration of the ethanol aqueous solution A is 80-90%.
[0020] Preferably, the aminosiloxane is selected from at least one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.
[0021] Preferably, the mass ratio of boric acid, phenylsiloxane, vinylsiloxane and aminosiloxane is 1:5-10:1-2:6-7.
[0022] Preferably, the amount of the ethanol aqueous solution A added is 1.2-1.5 times the total mass of boric acid, phenylsiloxane and vinylsiloxane.
[0023] Preferably, the pH is adjusted to 1-3 using hydrochloric acid, sulfuric acid, or p-toluenesulfonic acid.
[0024] Preferably, the mass ratio of the polyborosiloxane to ammonium polyphosphate is 1:6-10.
[0025] Specifically, the preparation method of the polyborosiloxane-modified ammonium polyphosphate includes the following steps:
[0026] Boric acid, phenylsiloxane, vinylsiloxane, and an aqueous ethanol solution A are mixed, the pH is adjusted, and the mixture is reacted at 70-90℃ for 1-3 hours. Aminosiloxane is added, and the reaction is continued for 1-3 hours. The mixture is then distilled under reduced pressure to obtain polyborosiloxane. Polyborosiloxane and ammonium polyphosphate are mixed, stirred at 8000-10000 rpm for 30-60 minutes, and then dried to obtain the final product.
[0027] In some preferred embodiments, the method for preparing the surface-modified vinyl borate phosphate-containing boehmite includes the following steps:
[0028] Boehmite was dispersed in an aqueous ethanol solution B, phytic acid and vinylsiloxane B were added, stirred, filtered, washed and dried to obtain phosphorus-containing boehmite; phosphorus-containing boehmite, vinyl borate ester, initiator and N,N-dimethylformamide were mixed evenly, heated and reacted, and the result was obtained after the reaction was completed.
[0029] Preferably, the boehmite has a D50 of 0.2-1µm and a Ca content of 1µm. 2+ Content <30ppm, Fe 3+ Content <10ppm, Cu 2+ Content <5ppm, Na + Content <100ppm.
[0030] Preferably, the mass concentration of the ethanol aqueous solution B is 80-90%.
[0031] Preferably, the vinylsiloxane B is selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri-(2-methoxyethoxy)-silane.
[0032] Preferably, the mass ratio of boehmite, aqueous ethanol solution B, phytic acid and vinylsiloxane B is 1:10-15:0.3-0.6:0.1-0.3.
[0033] Preferably, the vinyl borate ester is selected from at least one of vinyl borate pinacol ester and 2,2-dimethyl vinyl borate pinacol ester.
[0034] Preferably, the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, and azobisisoheptanenitrile.
[0035] Preferably, the mass ratio of the phosphorus-containing boehmite, vinyl borate ester, initiator and N,N-dimethylformamide is 1:0.4-0.6:0.01-0.04:10-20.
[0036] Specifically, the method for preparing the phosphorus-containing boehmite with surface-modified vinyl borate ester includes the following steps:
[0037] Boehmite was dispersed in an aqueous ethanol solution B, phytic acid and vinylsiloxane were added, and the mixture was stirred at 60-80℃ for 1-2 hours. After filtration, washing and drying, phosphorus-containing boehmite was obtained. Phosphorus-containing boehmite, vinyl borate ester, initiator and N,N-dimethylformamide were mixed evenly and heated to 70-80℃ for 2-4 hours. After the reaction was completed, the mixture was filtered, washed and dried to obtain the final product.
[0038] In some preferred embodiments, the glass fiber is chopped glass fiber, the chopped length of which is 2-6 mm and the diameter of the single filament is 10-15 μm.
[0039] In some preferred embodiments, the antioxidant is selected from at least one of hindered phenolic antioxidants, amine antioxidants, and phosphate antioxidants.
[0040] In some preferred embodiments, the lubricant is selected from at least one of calcium stearate, zinc stearate, and polyethylene wax.
[0041] A second aspect of the present invention provides a method for preparing a polyamide composite material, comprising the following steps:
[0042] PA66, modified halogen-free flame retardant, glass fiber, antioxidant and lubricant are mixed evenly in a mixer to obtain a premix. The premix is then melt-mixed in a screw extruder and extruded and granulated to obtain the final product.
[0043] Preferably, the twin-screw extruder rotates at a speed of 300-500 rpm.
[0044] Preferably, the extrusion temperature of the twin-screw extruder is 260-280℃.
[0045] The third aspect of this invention provides an application of polyamide composite materials in new energy charging facilities.
[0046] Compared with the prior art, the present invention has the following beneficial effects:
[0047] This invention utilizes a compound of polyborosiloxane-modified ammonium polyphosphate and surface-modified vinyl borate-containing boehmite as a modified halogen-free flame retardant. The polyborosiloxane-modified ammonium polyphosphate is first prepared using boric acid, phenylsiloxane, vinylsiloxane, and aminosiloxane to obtain polyborosiloxane, which is then coated onto the surface of the ammonium polyphosphate. The surface-modified vinyl borate-containing boehmite is first modified with phytic acid and vinylsiloxane to introduce phytic acid and vinyl groups, and then reacted with the phosphorus-containing boehmite using vinyl borate. The compound of polyborosiloxane-modified ammonium polyphosphate and surface-modified vinyl borosiloxane-containing boehmite achieves synergistic flame retardancy while avoiding the generation and accumulation of free carbon, thus improving CTI. On the other hand, it improves the compatibility of flame retardant with PA66 and avoids the influence of flame retardant on the weather resistance of polyamide composites under light conditions. Thus, the polyamide composites achieve high glow wire performance (960℃), high flame retardancy (V0), high CTI (≥700), and weather resistance (ΔE≤3.3).
[0048] The inventors also unexpectedly discovered during the experiment that the particle size and phosphorus content of boehmite impurities affect the glow wire properties and weather resistance of polyamide composites. When using D50 of 0.2-1µm, Ca... 2+ Content <30ppm, Fe 3+ Content <10ppm, Cu 2+ Content <5ppm, Na + Boehmite with a content of less than 100 ppm is more effective. Attached Figure Description
[0049] Figure 1Infrared spectrum of polyborosiloxane-modified ammonium polyphosphate A;
[0050] Figure 2 Infrared spectrum of phosphorus-containing boehmite A with surface-modified vinyl borate ester. Detailed Implementation
[0051] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.
[0052] Unless otherwise specified, the raw materials, reagents or apparatus used in the following examples and comparative examples are available from conventional commercial sources or can be obtained by existing known methods.
[0053] Example 1: Preparation of polyborosiloxane-modified ammonium polyphosphate A
[0054] 10g boric acid, 80g phenyltrimethoxysilane, 15g vinyltrimethoxysilane and 150g ethanol aqueous solution (mass concentration of 80%) were mixed, the pH was adjusted to 3 with hydrochloric acid, and the mixture was reacted at 80℃ for 2h. 65g 3-aminopropyltrimethoxysilane was added, and the reaction was continued for 2h. The mixture was then distilled under reduced pressure to obtain polyborosiloxane.
[0055] Mix 10g of polyborosiloxane and 80g of ammonium polyphosphate, stir at 10000rpm for 60min, and dry to obtain the final product.
[0056] The infrared spectrum of polyborosiloxane-modified ammonium polyphosphate A is as follows: Figure 1 As shown.
[0057] Example 2 Preparation of polyborosiloxane-modified ammonium polyphosphate B
[0058] 10g boric acid, 80g phenyltrimethoxysilane, 15g vinyltrimethoxysilane and 150g ethanol aqueous solution (mass concentration of 80%) were mixed, the pH was adjusted to 3 with hydrochloric acid, and the reaction was carried out at 80℃ for 4h. The mixture was then distilled under reduced pressure to obtain polyborosiloxane.
[0059] Mix 10g of polyborosiloxane and 80g of ammonium polyphosphate, stir at 10000rpm for 60min, and dry to obtain the final product.
[0060] Example 3 Preparation of Phosphorus-containing Boehmite A with Surface-Modified Vinyl Boronate
[0061] 10g of boehmite was dispersed in 120g of ethanol aqueous solution (mass concentration of 80%), 5g of phytic acid and 2g of vinyltriethoxysilane were added, and the mixture was stirred at 70℃ for 2h. After filtration, washing and drying, phosphorus-containing boehmite was obtained.
[0062] 10g of phosphorus-containing boehmite, 5g of vinyl borate pinacol ester, 0.2g of azobisisobutyronitrile and 150g of N,N-dimethylformamide were mixed evenly and reacted at 70℃ for 3h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the final product.
[0063] The boehmite has a D50 of 0.2-0.3 µm and a Ca content of 100 µm. 2+ Content <20ppm, Fe 3+ Content <10ppm, Cu 2+ Content <5ppm, Na + Content <50ppm, Suzhou Baird New Material Technology Co., Ltd., Model: BOE-501.
[0064] The infrared spectrum of phosphorus-containing boehmite A with surface-modified vinyl borate ester is shown below. Figure 2 As shown.
[0065] Example 4
[0066] Preparation of Phosphorus-containing Boehmite B with Surface-Modified Vinyl Borate
[0067] 10g of boehmite was dispersed in 120g of ethanol aqueous solution (mass concentration of 80%), 5g of phytic acid and 2g of vinyltriethoxysilane were added, and the mixture was stirred at 70℃ for 2h. After filtration, washing and drying, phosphorus-containing boehmite was obtained.
[0068] 10g of phosphorus-containing boehmite, 5g of vinyl borate pinacol ester, 0.2g of azobisisobutyronitrile and 150g of N,N-dimethylformamide were mixed evenly and reacted at 70℃ for 3h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the final product.
[0069] The boehmite has a D50 of 0.04-0.08 µm and a Ca content of 100 μm. 2+ Content <10ppm, Fe 3+ Content <5ppm, Cu 2+ Content <5ppm, Na + Content <5ppm, Suzhou Baird New Material Technology Co., Ltd., Model: BOE-500.
[0070] Example 5
[0071] Preparation of Phosphorus-containing Boehmite C with Surface-Modified Vinyl Borate
[0072] 10g of boehmite was dispersed in 120g of ethanol aqueous solution (mass concentration of 80%), 5g of phytic acid and 2g of vinyltriethoxysilane were added, and the mixture was stirred at 70℃ for 2h. After filtration, washing and drying, phosphorus-containing boehmite was obtained.
[0073] 10g of phosphorus-containing boehmite, 5g of vinyl borate pinacol ester, 0.2g of azobisisobutyronitrile and 150g of N,N-dimethylformamide were mixed evenly and reacted at 70℃ for 3h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the final product.
[0074] The boehmite has a D50 of 0.4-0.8 µm and a Ca content of 100 µm. 2+ Content <500ppm, Fe 3+ Content <50ppm, Cu 2+ Content <5ppm, Na + Content <500ppm, Anhui Yishitong Materials Technology Co., Ltd., Model: BG-601.
[0075] Example 6
[0076] Preparation of surface-modified vinyl borate boehmite
[0077] 10g of boehmite was dispersed in 120g of ethanol aqueous solution (mass concentration of 80%), 2g of vinyltriethoxysilane was added, and the mixture was stirred at 70℃ for 2h. The mixture was then filtered, washed, and dried to obtain boehmite.
[0078] 10g boehmite, 5g vinyl borate pinacol ester, 0.2g azobisisobutyronitrile and 150g N,N-dimethylformamide were mixed evenly and reacted at 70℃ for 3h. After the reaction was completed, the mixture was filtered, washed and dried to obtain the final product.
[0079] The boehmite has a D50 of 0.2-0.3 µm and a Ca content of 100 µm. 2+ Content <20ppm, Fe 3+ Content <10ppm, Cu 2+ Content <5ppm, Na + Content <50ppm, Suzhou Baird New Material Technology Co., Ltd., Model: BOE-501.
[0080] Example 7
[0081] Preparation of phosphorus-containing boehmite
[0082] 10g of boehmite was dispersed in 120g of ethanol aqueous solution (mass concentration of 80%), 5g of phytic acid and 2g of vinyltriethoxysilane were added, and the mixture was stirred at 70℃ for 2h. After filtration, washing and drying, phosphorus-containing boehmite was obtained.
[0083] Examples 8-17
[0084] The polyamide composite material was prepared, and its composition by mass parts is shown in Table 1.
[0085] PA66: What is PA66 EPR27?
[0086] Glass fiber: chopped glass fiber, wherein the chopped length of the chopped glass fiber is 3±1mm and the diameter of the single filament is 13μm, Shenzhen Xinxian Technology Co., Ltd., model: XGPA1303;
[0087] Antioxidant: Antioxidant 1098;
[0088] Lubricant: calcium stearate.
[0089] Table 1
[0090]
[0091] The preparation method of the above-mentioned polyamide composite material includes the following steps:
[0092] PA66, modified halogen-free flame retardant, glass fiber, antioxidant and lubricant are mixed evenly in a mixer to obtain a premix. The premix is then melt-mixed in a screw extruder and extruded and granulated to obtain the final product.
[0093] The twin-screw extruder operates at a speed of 400 rpm.
[0094] The extrusion temperature of the twin-screw extruder is 265°C.
[0095] Performance testing
[0096] The polyamide composite materials of the examples and comparative examples were injection molded into standard specimens and subjected to performance tests. The test items, test standards and test criteria are shown in Table 2 below.
[0097] Table 2
[0098]
[0099] The test results are shown in Table 3 below.
[0100] Table 3
[0101]
[0102] Examples 11-17 are all single variables compared to Example 9. Example 11 uses polyborosiloxane to modify ammonium polyphosphate B, resulting in a decrease in CTI and weather resistance of the polyamide composite material. This indicates that the polyborosiloxane prepared by boric acid, phenylsiloxane, vinylsiloxane and aminosiloxane coating the surface of ammonium polyphosphate can improve its compatibility with PA66 and phosphorus-containing boehmite with surface modified vinyl borate. It can interrupt carbonization at the high temperature generated by arc discharge and avoid the effect of ammonium polyphosphate on weather resistance.
[0103] Example 12 contained only phosphorus-containing boehmite A with surface-modified vinyl borate; Example 13 contained only polyborosiloxane-modified polyphosphate A. As can be seen from Examples 12 and 13, the combination of phosphorus-containing boehmite A with surface-modified vinyl borate and polyborosiloxane-modified polyphosphate A has a synergistic effect, which can improve the glow wire performance and flame retardant properties of polyamide composites while improving CTI.
[0104] Example 14 uses phosphorus-containing boehmite B with surface-modified vinyl borate; Example 15 uses phosphorus-containing boehmite C with surface-modified vinyl borate. As can be seen from Examples 14 and 15, the particle size and impurity content of boehmite affect the performance and weather resistance of hot wire.
[0105] Example 16 used boehmite with a surface modified vinyl borate, and Example 17 used phosphorus-containing boehmite. It can be seen from Examples 16 and 17 that phytic acid, vinyl borate, and boehmite can synergistically retard flame and synergistically improve the CTI performance of polyamide. In addition, modifying the surface of phosphorus-containing boehmite with vinyl borate can improve the weather resistance of polyamide, indicating that modifying the surface of phosphorus-containing boehmite with vinyl borate can improve its compatibility with PA66 and polyborosiloxane-modified ammonium polyphosphate.
[0106] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.
Claims
1. A polyamide composite material, characterized in that, The raw materials include the following parts by weight: PA66 50-70 parts, modified halogen-free flame retardant 5-10 parts, glass fiber 20-40 parts, antioxidant 0.1-1 parts, and lubricant 0.1-1 parts; The modified halogen-free flame retardant comprises polyborosiloxane-modified ammonium polyphosphate and phosphorus-containing boehmite with surface-modified vinyl borate in a mass ratio of 1-2:1-2. The preparation method of the polyborosiloxane-modified ammonium polyphosphate includes the following steps: Boric acid, phenylsiloxane, vinylsiloxane A, and aqueous ethanol solution A are mixed, the pH is adjusted, the reaction is initiated, aminosiloxane is added, the reaction continues, and the mixture is distilled under reduced pressure to obtain polyborosiloxane; polyborosiloxane and ammonium polyphosphate are mixed, stirred, and dried to obtain the final product. The method for preparing the phosphorus-containing boehmite with surface-modified vinyl borate ester includes the following steps: Boehmite was dispersed in an aqueous ethanol solution B, phytic acid and vinylsiloxane B were added, stirred, filtered, washed and dried to obtain phosphorus-containing boehmite; phosphorus-containing boehmite, vinyl borate ester, initiator and N,N-dimethylformamide were mixed evenly, heated and reacted, and the result was obtained after the reaction was completed. The vinylsiloxane A and vinylsiloxane B are independently selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltri-(2-methoxyethoxy)-silane; The boehmite has a D50 of 0.2-1µm and a Ca content of 1µm. 2+ Content <30ppm, Fe 3+ Content <10ppm, Cu 2+ Content <5ppm, Na + Content <100ppm.
2. The polyamide composite material according to claim 1, characterized in that, The relative viscosity of PA66 is 2.62-2.
72.
3. The polyamide composite material according to claim 2, characterized in that, The phenylsiloxane is selected from at least one of phenyltrimethoxysilane, phenyltriethoxysilane, methylphenyldimethoxysilane, and diphenyldimethoxysilane; the aminosiloxane is selected from at least one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.
4. The polyamide composite material according to claim 3, characterized in that, The vinyl borate ester is selected from at least one of vinyl borate pinacol ester and 2,2-dimethyl vinyl borate pinacol ester.
5. The method for preparing the polyamide composite material according to any one of claims 1-4, characterized in that, Includes the following steps: PA66, modified halogen-free flame retardant, glass fiber, antioxidant and lubricant are mixed evenly in a mixer to obtain a premix. The premix is then melt-mixed in a screw extruder and extruded and granulated to obtain the final product.
6. The application of the polyamide composite material according to any one of claims 1-4 in new energy charging facilities.