High-strength weather-resistant pbt composite material and preparation method thereof

Abstract

The application relates to the technical field of high polymer materials, in particular to a high-strength weather-resistant PBT composite material and a preparation method thereof. The PBT composite material is composed of the following raw materials in parts by weight: 100 parts of polybutylene terephthalate, 12-16 parts of modified glass fiber, 5-10 parts of filler, 0.1-0.3 parts of antioxidant, and 0.2-0.5 parts of compatilizer. The PBT composite material has high strength, excellent weather resistance and flame retardance, and good dimensional stability.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a high-strength, weather-resistant PBT composite material and its preparation method. Background Technology

[0002] Polybutylene terephthalate (PBT) is a translucent or opaque, crystalline thermoplastic polyester resin, also known as polytetramethyl terephthalate. PBT possesses excellent mechanical properties, good electrical insulation, chemical resistance, and rapid crystallization, making it widely used in the automotive industry, electronics, machinery, and fiber optic sheathing. Especially in structural components requiring high strength and dimensional stability, PBT is often modified through glass fiber reinforcement and inorganic filler filling to meet higher performance requirements.

[0003] However, during long-term outdoor use, PBT materials are susceptible to the combined erosion of ultraviolet radiation, oxygen, and humid and hot environments, resulting in ester hydrolysis, molecular chain breakage and degradation. This leads to yellowing and powdering of the material surface, a significant decrease in mechanical properties, and a severely shortened service life. In particular, the aging rate of PBT is accelerated under high temperature, high humidity, and strong sunlight environments, which greatly limits its widespread application in long-term outdoor service scenarios.

[0004] To overcome the above shortcomings, existing technologies mainly adopt the following improvement strategies: First, adding antioxidants, light stabilizers, and other additives to the PBT matrix to delay thermo-oxidative and photo-aging processes; second, introducing reinforcing fillers such as glass fiber and talc to improve the material's mechanical strength and dimensional stability; and third, improving the interfacial bonding between the filler and the matrix and reducing defects through surface modification or coupling agent treatment. However, these methods still have many bottlenecks. For example, conventional antioxidants and light stabilizers are prone to volatilization or migration during long-term aging, and their protective effect gradually diminishes; although simply adding glass fiber can improve strength, the interfacial bonding between the fiber and the resin is weak, and severe debonding occurs after aging, which accelerates the decline in mechanical properties; ordinary talc fillers have poor dispersibility, are prone to agglomeration, and cannot provide effective flame retardancy and long-term weather resistance protection. More importantly, most existing technologies target only one aging factor and lack multiple synergistic protection mechanisms, making it difficult to simultaneously meet the comprehensive requirements of high strength, high flame retardancy, excellent weather resistance, and good dimensional stability.

[0005] Therefore, developing a PBT composite material that combines high strength, excellent weather resistance, good flame retardancy, and dimensional stability has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the primary objective of this invention is to provide a high-strength weather-resistant PBT composite material, which has high strength, excellent weather resistance and flame retardant properties, and good dimensional stability.

[0007] Another objective of this invention is to provide a method for preparing a high-strength, weather-resistant PBT composite material. This method is simple, easy to operate, and operates under mild conditions, making it suitable for industrial production.

[0008] The objective of this invention is achieved through the following technical solution: A high-strength, weather-resistant PBT composite material is composed of the following raw materials in parts by weight: 100 parts polybutylene terephthalate, 12-16 parts modified glass fiber, 5-10 parts filler, 0.1-0.3 parts antioxidant, and 0.2-0.5 parts compatibilizer; The preparation process of the modified glass fiber is as follows: (1) Hydroxylated glass fiber and silane coupling agent were added to an aqueous ethanol solution, heated to react, and purified to obtain silane coupling agent modified glass fiber; (2) The glass fiber modified by the silane coupling agent was added to N,N-dimethylformamide, and then epoxy-terminated polyurethane resin and triethylamine were added. The mixture was heated and reacted, and then purified to obtain pre-modified glass fiber. (3) Add talc and polyvinyl alcohol to water, then add the pre-modified glass fiber, heat and stir, purify, and obtain the modified glass fiber.

[0009] The preparation principle of the modified glass fiber of this invention is as follows: First, hydroxylated glass fibers are modified with a silane coupling agent to introduce amino groups. The amino groups undergo a nucleophilic ring-opening addition reaction with terminal epoxy-based polyurethane resin, and the flexible polyurethane molecules are fixed to the glass fiber surface through carbon-nitrogen covalent bonds. Then, the amphiphilic polymer properties of polyvinyl alcohol are utilized to achieve uniform dispersion and stable coating of talc powder. Polyvinyl alcohol molecules have both hydrophilic hydroxyl groups and hydrophobic carbon chain structures. In an aqueous system, they can effectively inhibit the agglomeration and sedimentation of layered talc powder through steric hindrance and electrostatic adsorption, achieving uniform dispersion of single talc particles. At the same time, polyvinyl alcohol can be simultaneously adsorbed on the surface of the pre-modified glass fiber and the surface of the talc particles, constructing a flexible bonding bridge, so that the talc particles are uniformly and firmly physically deposited and coated on the polyurethane grafted modified glass fiber surface.

[0010] Preferably, in step (1), the mass ratio of hydroxylated glass fiber to silane coupling agent is 1:(3-4); the silane coupling agent is KH550; the heating reaction temperature is 70-80℃ and the time is 3-5h.

[0011] Preferably, in step (2), the mass ratio of the silane coupling agent-modified glass fiber, the terminal epoxy polyurethane resin, and the triethylamine is 1:(2-4):(0.03-0.1); the heating reaction temperature is 105-110℃ and the time is 1-3h.

[0012] Preferably, the mass ratio of talc, polyvinyl alcohol and pre-modified glass fiber in step (3) is 1:(0.1-0.3):(0.1-0.3); the heating and stirring temperature is 40-50℃ and the time is 1-3h.

[0013] Preferably, the preparation process of the filler is as follows: (a) Add talc to zinc chloride solution, then add strong base, stir and purify to obtain pre-modified talc; (b) The pre-modified talc powder is added to water, sodium alginate is added, ultrasonic treatment is performed, the mixture is allowed to stand, the precipitate is collected, washed, and then soaked in phytic acid solution to obtain the filler.

[0014] The preparation principle of the filler of this invention is as follows: the filler is prepared by sequential activation with zinc salt and strong alkali, coating with sodium alginate, and chelation modification with phytic acid. Specifically: First, zinc chloride reacts with a strong alkali to generate zinc oxide, which is loaded onto the surface of talc powder to activate the powder and increase active sites; second, sodium alginate coats the activated talc powder surface by means of intermolecular forces, improving the powder dispersion performance; finally, phytic acid forms a dense protective layer on the powder surface through coordination chelation and hydrogen bonding cross-linking.

[0015] Preferably, in step (a), the ratio of talc powder, zinc chloride solution, and strong alkali is 1g:(10-12)mL:(0.2-0.3)g; the strong alkali is sodium hydroxide or potassium hydroxide; the concentration of the zinc chloride solution is 0.1-0.2mol / L; and the stirring time is 1-3h.

[0016] Preferably, in step (b), the mass ratio of sodium alginate to pre-modified talc is 1:(4-6); the volume ratio of precipitate to phytic acid solution is 1g:(20-25)mL; the concentration of phytic acid solution is 9-11wt%; the power of ultrasonic treatment is 100-200W, and the time is 3-4h; the standing time is 5-8h; and the soaking time is 40-60min.

[0017] Preferably, the antioxidant is antioxidant 1010 or antioxidant 1076; the compatibilizer is maleic anhydride-grafted polyethylene.

[0018] The preparation method of the above-mentioned high-strength weather-resistant PBT composite material includes the following steps: The raw material is added to a twin-screw extruder, melt-extruded, cooled, and pelletized to obtain the final product.

[0019] Preferably, the temperature of the melt extrusion is 230-260°C.

[0020] The present invention has the following advantages over the prior art: (1) This invention provides a high-strength, weather-resistant PBT composite material, comprising polybutylene terephthalate, modified glass fiber, filler, antioxidant, compatibilizer, and other raw materials. This composite material has high strength, excellent weather resistance and flame retardant properties, and good dimensional stability.

[0021] (2) This invention improves the weather resistance of the composite material by introducing modified glass fiber. On the one hand, the talc powder on the surface of the modified glass fiber has a layered silicate structure, which can form a labyrinthine barrier channel inside the composite material, effectively delaying the penetration and diffusion of water vapor, oxygen and ultraviolet rays. On the other hand, the surface-grafted saturated polyurethane segments have excellent resistance to ultraviolet rays and heat-oxidative aging, which can effectively shield external aging factors and protect the PBT matrix molecular chains from damage. In addition, the dense coating layer constructed with polyvinyl alcohol can further reduce fiber surface defects and reduce interfacial aging sites. The synergistic effect of multiple protection mechanisms significantly improves the resistance to ultraviolet aging, damp heat aging and heat-oxidative aging of PBT composite material, and extends the service life of the material.

[0022] (3) This invention improves the rigidity, dimensional stability, flame retardancy, and weather resistance of the composite material by introducing fillers. After adding fillers to PBT, the talc and zinc oxide in them can effectively reinforce the matrix and improve the rigidity and dimensional stability of the material. The zinc (ZnO) and phosphorus (phytic acid) elements in the filler shell form a highly efficient phosphorus-zinc synergistic flame retardant system during combustion. When heated, phytic acid decomposes to generate polyphosphoric acid, which promotes the dehydration and char formation of the PBT matrix. At the same time, it reacts with ZnO to form a dense glassy protective layer of zinc phosphate in situ. Sodium alginate dehydrates at high temperature to form a dense, continuous, and thermally stable carbon layer, which can effectively isolate heat, oxygen, and combustible gases, and significantly improve the limiting oxygen index of the composite material. In addition, the ZnO and zinc phosphate layers can not only catalyze char formation, but also efficiently adsorb smoke particles, showing a significant smoke suppression effect. The dual physical barrier of the rigid talc sheet and the dense carbon layer on the surface can greatly increase the viscosity of PBT in the molten state, effectively suppress the molten dripping phenomenon during combustion, and improve the safety of the material. Meanwhile, the organic modification of the filler surface reduces the surface energy of the filler, reduces the tendency of particle aggregation, makes it easier to disperse uniformly in the PBT matrix, and improves the processing performance; its surface protective structure can block external corrosive factors, delay the hydrolysis and aging of the PBT matrix, thereby further improving the weather resistance of the composite material.

[0023] (4) The present invention also provides a method for preparing a high-strength weather-resistant PBT composite material. The preparation method is simple, easy to operate, and has mild conditions, making it easy to industrialize. Attached Figure Description

[0024] Figure 1 SEM image of the modified glass fiber obtained in Example 1 of this invention; Figure 2 The image shows a SEM image of the packing material obtained in Example 4 of this invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field. Test methods in the following embodiments that do not specify specific experimental conditions are generally performed according to conventional experimental conditions or experimental conditions recommended by the manufacturer. Unless otherwise specified, the reagents and raw materials used in the present invention are commercially available.

[0026] The glass fiber of this invention has a diameter of 15-20 μm.

[0027] Preparation Example 1 The preparation process of modified glass fiber is as follows: (1) Add 30wt% hydrogen peroxide dropwise to the glass fiber at a ratio of 1g:25mL, stir evenly, reflux for 4h, filter, and dry to obtain hydroxylated glass fiber; add the above hydroxylated glass fiber and KH550 to a 75% (v / v) ethanol aqueous solution at a ratio of 1g:3.5g:100mL, react at 75℃ for 4h, filter, and vacuum dry to obtain silane coupling agent modified glass fiber; (2) The glass fiber modified with silane coupling agent, the epoxy-terminated polyurethane resin, triethylamine and DMF are used in a ratio of 1g:3g:0.05g:25mL. The glass fiber modified with the above silane coupling agent is dispersed in N,N-dimethylformamide (DMF), and then epoxy-terminated polyurethane resin (viscosity of 60000mPa·s) and triethylamine are added. The mixture is reacted at 108℃ for 2h, filtered, washed and dried to obtain pre-modified glass fiber. (3) Using talc powder, polyvinyl alcohol, pre-modified glass fiber and water in a ratio of 1g:0.2g:0.2g:90mL, add talc powder and polyvinyl alcohol to water, mix evenly, add the above pre-modified glass fiber, stir at 45℃ for 2h, filter, wash and dry to obtain modified glass fiber.

[0028] Preparation Example 2 The preparation process of modified glass fiber is as follows: (1) Add 30wt% hydrogen peroxide dropwise to the glass fiber with a ratio of glass fiber to hydrogen peroxide of 1g:25mL, stir evenly, reflux for 3h, filter, and dry to obtain hydroxylated glass fiber; add the above hydroxylated glass fiber and KH550 to a 75% (v / v) ethanol aqueous solution with a ratio of 1g:3g:100mL, react at 70℃ for 5h, filter, and vacuum dry to obtain silane coupling agent modified glass fiber; (2) The glass fiber modified with silane coupling agent, the epoxy-terminated polyurethane resin, triethylamine and DMF are used in a ratio of 1g:2g:0.03g:25mL. The glass fiber modified with the silane coupling agent is dispersed in DMF, and then epoxy-terminated polyurethane resin (viscosity of 50000mPa·s) and triethylamine are added. The mixture is reacted at 105℃ for 3h, filtered, washed and dried to obtain pre-modified glass fiber. (3) Using talc powder, polyvinyl alcohol, pre-modified glass fiber and water in a ratio of 1g:0.1g:0.1g:90mL, add talc powder and polyvinyl alcohol to water, mix evenly, add the above pre-modified glass fiber, stir at 40℃ for 3h, filter, wash and dry to obtain modified glass fiber.

[0029] Preparation Example 3 The preparation process of modified glass fiber is as follows: (1) Add 30wt% hydrogen peroxide dropwise to the glass fiber with a ratio of glass fiber to hydrogen peroxide of 1g:25mL, stir evenly, reflux for 5h, filter, and dry to obtain hydroxylated glass fiber; add the above hydroxylated glass fiber and KH550 to a 75% (v / v) ethanol aqueous solution with a ratio of 1g:4g:100mL, react at 80℃ for 3h, filter, and vacuum dry to obtain silane coupling agent modified glass fiber; (2) The glass fiber modified with silane coupling agent, the epoxy-terminated polyurethane resin, triethylamine and DMF are used in a ratio of 1g:4g:0.1g:25mL. The glass fiber modified with the silane coupling agent is dispersed in DMF, and then epoxy-terminated polyurethane resin (viscosity of 80000mPa·s) and triethylamine are added. The mixture is reacted at 110℃ for 1h, filtered, washed and dried to obtain pre-modified glass fiber. (3) Using talc, polyvinyl alcohol, pre-modified glass fiber and water in a ratio of 1g:0.3g:0.3g:90mL, add talc and polyvinyl alcohol to water, mix evenly, add the above pre-modified glass fiber, stir at 50℃ for 1h, filter, wash and dry to obtain modified glass fiber.

[0030] Preparation Example 4 The preparation process of the filler is as follows: (a) With a ratio of 1g:11mL:0.25g of talc powder, zinc chloride solution and sodium hydroxide, talc powder was added to a 0.15mol / L zinc chloride solution, and then sodium hydroxide was added. The mixture was stirred at room temperature for 2 hours, filtered, washed and dried to obtain pre-modified talc powder. (b) Using sodium alginate, pre-modified talc, and water in a ratio of 1g:5g:100mL, add the pre-modified talc to water, then add sodium alginate, sonicate at 150W for 3.5h, let stand for 6h, collect the precipitate, and wash it; using the ratio of precipitate to phytic acid solution of 1g:22mL, soak the precipitate in a 10wt% phytic acid solution for 50min to obtain the filler.

[0031] Preparation Example 5 The preparation process of the filler is as follows: (a) With a ratio of 1g:10mL:0.2g of talc powder, zinc chloride solution and potassium hydroxide, talc powder was added to 0.1mol / L zinc chloride solution, and then potassium hydroxide was added. The mixture was stirred at room temperature for 1h, filtered, washed and dried to obtain pre-modified talc powder. (b) Using sodium alginate, pre-modified talc, and water in a ratio of 1g:4g:100mL, add the pre-modified talc to water, then add sodium alginate, sonicate at 100W for 4h, let stand for 5h, collect the precipitate, and wash it; using the ratio of precipitate to phytic acid solution of 1g:20mL, soak the precipitate in a 9wt% phytic acid solution for 40min to obtain the filler.

[0032] Preparation Example 6 The preparation process of the filler is as follows: (a) With a ratio of 1g:12mL:0.3g of talc powder, zinc chloride solution and sodium hydroxide, talc powder was added to 0.2mol / L zinc chloride solution, and then sodium hydroxide was added. The mixture was stirred at room temperature for 3 hours, filtered, washed and dried to obtain pre-modified talc powder. (b) Using sodium alginate, pre-modified talc, and water in a ratio of 1g:6g:100mL, add the pre-modified talc to water, then add sodium alginate, sonicate at 200W for 3h, let stand for 8h, collect the precipitate, and wash it; using the ratio of precipitate to phytic acid solution of 1g:25mL, soak the precipitate in 11wt% phytic acid solution for 60min to obtain the filler.

[0033] Example 1 A high-strength, weather-resistant PBT composite material is composed of the following raw materials in parts by weight: 100 parts of polybutylene terephthalate, 13 parts of modified glass fiber of Preparation Example 1, 7 parts of filler of Preparation Example 4, 0.2 parts of antioxidant 1076, and 0.3 parts of maleic anhydride-grafted polyethylene.

[0034] The preparation method of the above-mentioned high-strength weather-resistant PBT composite material includes the following steps: The raw material is added to a twin-screw extruder, melt-extruded, cooled, and pelletized to obtain the final product. The temperature settings for each heating zone of the twin-screw extruder are as follows: Zone 1 230℃, Zone 2 240℃, Zone 3 250℃, Zone 4 260℃, Zone 5 260℃, Zone 6 255℃, Zone 7 250℃, Zone 8 245℃, and the die head 240℃.

[0035] Example 2 A high-strength, weather-resistant PBT composite material is composed of the following raw materials in parts by weight: 100 parts of polybutylene terephthalate, 12 parts of modified glass fiber of Preparation Example 2, 5 parts of filler of Preparation Example 5, 0.1 parts of antioxidant 1010, and 0.2 parts of maleic anhydride-grafted polyethylene.

[0036] The preparation method of the above-mentioned high-strength weather-resistant PBT composite material includes the following steps: The raw material is added to a twin-screw extruder, melt-extruded, cooled, and pelletized to obtain the final product. The temperature settings for each heating zone of the twin-screw extruder are as follows: Zone 1 230℃, Zone 2 240℃, Zone 3 250℃, Zone 4 260℃, Zone 5 260℃, Zone 6 255℃, Zone 7 250℃, Zone 8 245℃, and the die head 240℃.

[0037] Example 3 A high-strength, weather-resistant PBT composite material is composed of the following raw materials in parts by weight: 100 parts of polybutylene terephthalate, 16 parts of modified glass fiber of Preparation Example 3, 10 parts of filler of Preparation Example 6, 0.3 parts of antioxidant 1076, and 0.5 parts of maleic anhydride-grafted polyethylene.

[0038] The preparation method of the above-mentioned high-strength weather-resistant PBT composite material includes the following steps: The raw material is added to a twin-screw extruder, melt-extruded, cooled, and pelletized to obtain the final product. The temperature settings for each heating zone of the twin-screw extruder are as follows: Zone 1 230℃, Zone 2 240℃, Zone 3 250℃, Zone 4 260℃, Zone 5 260℃, Zone 6 255℃, Zone 7 250℃, Zone 8 245℃, and the die head 240℃.

[0039] Comparative Example 1 The difference between this comparative example and Example 1 is that the modified glass fiber of Preparation Example 1 is replaced with the silane coupling agent modified glass fiber of Preparation Example 1.

[0040] Comparative Example 2 The difference between this comparative example and Example 1 is that the filler in Preparation Example 4 was replaced with talc.

[0041] Experimental Example 1 The modified glass fiber obtained in Preparation Example 1 and the filler obtained in Preparation Example 4 were characterized by scanning electron microscopy (SEM). The microstructure results are as follows: Figure 1-2 As shown.

[0042] Figure 1 SEM image of the modified glass fiber obtained in Example 1. Observation Figure 1 It is known that modified glass fibers, after being grafted with silane coupling agents, modified with terminal epoxy polyurethane resin, and coated with talc-polyvinyl alcohol composite, have a rough and uniform surface with no exposed smooth areas, forming a dense and uniform composite coating layer.

[0043] Figure 2 SEM image of the packing material obtained in Example 4. Observation Figure 2 It can be seen that the talc filler after zinc salt activation, sodium alginate coating, and phytic acid chelation modification has a complete organic-inorganic composite film layer on the particle surface, and the particle outline is regular and the structure is dense.

[0044] Experimental Example 2 The PBT composite materials of the examples or comparative examples were injection molded on an injection molding machine to prepare samples, and then performance tests were performed according to the following method: UV aging resistance: Tested according to GB / T 16422.3-2022 standard (exposure conditions: radiation temperature 50℃, irradiation time 5h, irradiation intensity 0.8W / m²). 2 The blackboard temperature was 20℃, and water was sprayed for 1 hour; the aging time was 200 hours. The tensile strength of the composite material was tested before and after aging according to ISO 527 method (tensile speed 5 mm / min), and the tensile strength retention rate was calculated to evaluate the UV aging resistance.

[0045] Heat and oxygen aging resistance: The test conditions were 180℃ and hot air oxidation for 600 hours. The tensile strength of the composite material was tested before and after aging according to ISO 527 method (tensile speed 5 mm / min), and the tensile strength retention rate was calculated to evaluate the heat and oxygen aging resistance performance.

[0046] Moist heat aging resistance: The test conditions are 90℃ temperature, 85% relative humidity, and 260h storage. Tensile strength is tested before and after aging according to ISO 527 method (tensile speed 5 mm / min), and the tensile strength retention rate is calculated to evaluate the moisture heat aging resistance performance.

[0047] Flexural modulus: Tested according to ISO 178 method at a test speed of 2 mm / min.

[0048] Limiting oxygen index: Tested in accordance with GB / T 2406.2-2009.

[0049] Dimensional stability: Tested according to GB / T 17037.4-2003. The test results are shown in Table 1.

[0050] Table 1 According to the experimental data in Table 1, the PBT composite materials prepared in Examples 1-3 of this invention exhibit excellent performance in all aspects. Compared with Comparative Example 1, where the modified glass fiber was replaced with glass fiber modified only by silane coupling agent, Example 1 shows significantly better resistance to UV radiation, heat and oxygen, and damp heat aging. Compared with Comparative Example 2, where the filler was replaced with unmodified talc, Example 1 shows significantly better limiting oxygen index, flexural modulus, and shrinkage. The above results indicate that this invention significantly improves the flame retardancy, rigidity, weather resistance, and dimensional stability of PBT composite materials through the synergistic effect of modified glass fiber and filler.

[0051] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A high-strength, weather-resistant PBT composite material, characterized in that, It is composed of the following raw materials in parts by weight: 100 parts polybutylene terephthalate, 12-16 parts modified glass fiber, 5-10 parts filler, 0.1-0.3 parts antioxidant, and 0.2-0.5 parts compatibilizer; The preparation process of the modified glass fiber is as follows: (1) Hydroxylated glass fiber and silane coupling agent were added to an aqueous ethanol solution, heated to react, and purified to obtain silane coupling agent modified glass fiber; (2) The glass fiber modified by the silane coupling agent was added to N,N-dimethylformamide, and then epoxy-terminated polyurethane resin and triethylamine were added. The mixture was heated and reacted, and then purified to obtain pre-modified glass fiber. (3) Add talc and polyvinyl alcohol to water, then add the pre-modified glass fiber, heat and stir, purify, and obtain the modified glass fiber.

2. The high-strength, weather-resistant PBT composite material according to claim 1, characterized in that, In step (1), the mass ratio of hydroxylated glass fiber to silane coupling agent is 1:(3-4); the silane coupling agent is KH550; the heating reaction temperature is 70-80℃ and the time is 3-5h.

3. The high-strength, weather-resistant PBT composite material according to claim 1, characterized in that, In step (2), the mass ratio of the silane coupling agent-modified glass fiber, the terminal epoxy polyurethane resin, and the triethylamine is 1:(2-4):(0.03-0.1); the heating reaction temperature is 105-110℃ and the time is 1-3h.

4. The high-strength, weather-resistant PBT composite material according to claim 1, characterized in that, In step (3), the mass ratio of talc, polyvinyl alcohol, and pre-modified glass fiber is 1:(0.1-0.3):(0.1-0.3); the heating and stirring temperature is 40-50℃ and the time is 1-3h.

5. The high-strength, weather-resistant PBT composite material according to claim 1, characterized in that, The preparation process of the filler is as follows: (a) Add talc to zinc chloride solution, then add strong base, stir and purify to obtain pre-modified talc; (b) The pre-modified talc powder is added to water, sodium alginate is added, ultrasonic treatment is performed, the mixture is allowed to stand, the precipitate is collected, washed, and then soaked in phytic acid solution to obtain the filler.

6. The high-strength, weather-resistant PBT composite material according to claim 5, characterized in that, In step (a), the ratio of talc powder, zinc chloride solution, and strong alkali is 1g:(10-12)mL:(0.2-0.3)g; the strong alkali is sodium hydroxide or potassium hydroxide; the concentration of the zinc chloride solution is 0.1-0.2mol / L; and the stirring time is 1-3h.

7. The high-strength, weather-resistant PBT composite material according to claim 5, characterized in that, In step (b), the mass ratio of sodium alginate to pre-modified talc is 1:(4-6); the volume ratio of precipitate to phytic acid solution is 1g:(20-25)mL; the concentration of phytic acid solution is 9-11wt%; the ultrasonic treatment power is 100-200W and the time is 3-4h; the standing time is 5-8h; and the soaking time is 40-60min.

8. The high-strength, weather-resistant PBT composite material according to claim 1, characterized in that, The antioxidant is antioxidant 1010 or antioxidant 1076; the compatibilizer is maleic anhydride-grafted polyethylene.

9. A method for preparing a high-strength, weather-resistant PBT composite material according to any one of claims 1-8, characterized in that, Includes the following steps: The raw material is added to a twin-screw extruder, melt-extruded, cooled, and pelletized to obtain the final product.

10. The method for preparing the high-strength weather-resistant PBT composite material according to claim 9, characterized in that, The temperature of the melt extrusion is 230-260℃.

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