High-strength PC composite material and preparation method thereof

Abstract

The invention relates to a high-strength PC composite material and a preparation method thereof, and belongs to the technical field of PC composite materials. The material comprises the following raw materials: bisphenol A polycarbonate, carbon fibers, nano silicate, an intumescent flame retardant and a silane coupling agent derivative. The silane coupling agent derivative is a copolymer of a silane coupling agent KH571 and benzotriazole, is prepared through a photo-initiated thiol-ene click chemical reaction, and is grafted on the surface of the carbon fiber to form an interface enhanced network. The balance of high strength and high flame retardance of the PC material is realized through macroscopic reinforcement of the short carbon fibers, microcosmic reinforcement of the nano silicate and synergism of the intumescent flame retardant, and the PC material is suitable for the fields of electronic appliances, automobile parts and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of PC composite materials and relates to a high-strength PC composite material and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) is a high-performance engineering thermoplastic that is widely used in various fields, including electronics, automobiles, construction, and medical devices, due to its excellent mechanical properties, transparency, and heat resistance. As an amorphous polymer, the molecular structure of PC material gives it good toughness and impact strength, enabling it to perform well in many demanding applications. PC material is widely used as a substitute for glass due to its optical transparency, especially in applications requiring high strength and impact resistance, such as bulletproof glass and goggles. In addition, PC also has good dimensional stability and can maintain its physical properties even at high temperatures, which makes it very popular in injection molding processes.

[0003] In order to enhance the strength and other properties of PC materials, researchers and engineers have made many attempts and innovations. Adding fillers is a common method to improve the strength of PC materials. Carbon fiber is widely used as a reinforcing material due to its high strength and high modulus properties. By compounding it with the PC matrix, the tensile strength and rigidity of the composite material can be significantly improved. In addition, the introduction of nanofiller salts can also improve the mechanical properties and thermal stability of PC composites. The high specific surface area and unique physical and chemical properties of nanomaterials enable them to exhibit excellent performance in interfacial bonding with the polymer matrix, which can significantly improve the overall strength and heat resistance of the material. However, how to rationally design and disperse these reinforcing materials to achieve the best performance improvement effect remains a technical challenge.

[0004] Although existing technologies have made certain progress in improving the performance of PC composites, some shortcomings still exist. First, the uniform dispersion of the reinforcing material in the matrix is one of the key factors affecting the performance of the composite material. Since fillers easily agglomerate, they are unevenly distributed in the composite material, which limits their reinforcement effect. In addition, the interfacial compatibility between the reinforcing material and the PC matrix also affects the overall performance of the composite material. Poor interfacial bonding may lead to stress concentration and material failure. Secondly, existing flame retardant reinforcement technologies often reduce the mechanical properties of the material. How to improve flame retardancy without losing mechanical properties is an urgent problem to be solved. Therefore, it is particularly important to develop new chemical modification technologies and optimize the preparation process of composite materials to improve the dispersion and interfacial bonding of reinforcing materials. These technical improvements will help improve the comprehensive performance of PC composites and broaden their application range. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-strength PC composite material and a preparation method thereof, which realizes high strength and high flame retardancy of PC material through the synergistic reinforcement mechanism of chopped carbon fiber and nano-silicate, combined with environmentally friendly intumescent flame retardant and interface modification technology.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A high-strength PC composite material comprises the following components in parts by weight: 70-90 parts of bisphenol A polycarbonate, 5-15 parts of carbon fibers, 3-8 parts of nano-silicate, 3-6 parts of intumescent flame retardant, and 0.5-2 parts of silane coupling agent derivative;

[0008] The carbon fibers are modified with epoxy groups;

[0009] The silane coupling agent derivative is a copolymer obtained by a click reaction between the silane coupling agent KH571 and mercaptobenzotriazole, which occurs between mercapto groups and olefins.

[0010] As a preferred technical solution of the present invention, the preparation method of the silane coupling agent derivative comprises the following steps:

[0011] A1, benzotriazole and succinic anhydride react at 80-100°C for 6-8 hours under the catalysis of 4-dimethylaminopyridine. 4-Dimethylaminopyridine catalyzes the ring opening of succinic anhydride and undergoes nucleophilic substitution with the NH bond of benzotriazole to form a benzotriazole-carboxylic anhydride intermediate. The carboxylic anhydride group provides an active site for subsequent hydrolysis and thiolation.

[0012] A2, hydrolyzing the benzotriazole-carboxylic anhydride intermediate obtained in step A1 with a hydrochloric acid solution, and hydrolyzing the anhydride bond into a carboxylic acid in dilute hydrochloric acid to obtain carboxybenzotriazole;

[0013] A3, condensing the carboxyl-containing benzotriazole prepared in step A2 with mercaptoethylamine using 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole as condensing agents; 1-ethyl-(3-dimethylaminopropyl)carbodiimide activates the carboxylic acid to generate an O-acylisourea intermediate, which is converted by 1-hydroxybenzotriazole into a stable ester; and mercaptoethylamine nucleophilically attacks the benzotriazole to form an amide bond, thereby generating mercaptobenzotriazole;

[0014] A4. The mercaptobenzotriazole and KH571 prepared in step A3 are irradiated with UV light under the photoinitiator condition of Irgacure 819. Irgacure 819 absorbs UV light to generate active free radicals, which trigger a thiol-ene click reaction between the thiol (-SH) and the allyl group (C=C) of KH571, forming a C-S covalent bond, thereby forming a silane coupling agent derivative of the KH571-mercaptobenzotriazole copolymer.

[0015] As a preferred technical solution of the present invention, the mass ratio of benzotriazole, succinic anhydride, and 4-dimethylaminopyridine in step A1 is 1:0.85-1.2:0.05-0.15.

[0016] As a preferred technical solution of the present invention, the molar ratio of the benzotriazole-carboxylic anhydride intermediate to hydrochloric acid in step A2 is 1:1.5-2.5; and the concentration of the hydrochloric acid solution is 1-3M.

[0017] As a preferred technical solution of the present invention, the condensing agent in step A3 is 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in a mass ratio of 0.85-1.1:0.6-0.8; the mass ratio of the carboxybenzotriazole, mercaptoethylamine, and condensing agent is 1:035-0.45:1.6-2.0.

[0018] As a preferred technical solution of the present invention, the mass ratio of benzotriazole-SH, KH571, and Irgacure819 in step A4 is 1:0.8-1.2:0.005-0.02.

[0019] As a preferred technical solution of the present invention, the carbon fiber is chopped carbon fiber with a length of 100-300 μm and a diameter of 5-8 μm.

[0020] As a preferred technical solution of the present invention, the nano-silicate is montmorillonite or halloysite, and the particle size is 20-50 nm.

[0021] As a preferred technical solution of the present invention, the intumescent flame retardant is ammonium polyphosphate and melamine cyanurate in a mass ratio of 2-3:1.

[0022] Furthermore, the method for preparing the high-strength PC composite material comprises the following steps:

[0023] (1) Immersing carbon fiber in an epichlorohydrin / acetone solution with a volume ratio of 1:4-6, reacting at 70-90° C. for 3-5 hours, and then mixing with nano-silicate and silane coupling agent derivatives and ultrasonically dispersing for 30-60 minutes to form a premix;

[0024] (2) melt-blending bisphenol A polycarbonate, premix, and intumescent flame retardant at 250-280° C.;

[0025] (3) PC composite materials were obtained by extrusion and granulation.

[0026] Beneficial effects of the present invention:

[0027] (1) The present invention provides a macroscopic reinforcement skeleton for the PC composite material by chopped carbon fibers, thereby improving the material strength; and further improves the material strength by filling with nano-silicates.

[0028] (2) The present invention prepares a modified silane coupling agent through carboxylation-thiolation-click polymerization of benzotriazole, and the molecular chain contains a benzotriazole group and a thiol group; the nitrogen heterocycle of benzotriazole and the ester group of PC can form a hydrogen bond, and the thiol group is bonded to the epoxy group on the surface of the chopped carbon fiber, thereby improving the interface compatibility between the carbon fiber and the PC matrix, thereby improving the mechanical properties of the material; and the anti-ultraviolet property of benzotriazole gives the PC composite material anti-aging properties.

[0029] (3) The present invention uses ammonium polyphosphate and melamine cyanurate in a mass ratio of 2-3:1 as intumescent flame retardants, which release non-combustible gas at high temperatures to isolate oxygen and heat; and the benzotriazole group in the silane coupling agent is bonded to the phosphorus group of ammonium polyphosphate to prevent the flame retardant from migrating at high temperatures and improve thermal stability. DETAILED DESCRIPTION

[0030] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0031] The sources of raw materials involved in the following examples and comparative examples are as follows: the bisphenol A polycarbonate was purchased from Shengchen Chemical Co., Ltd.; carbon fiber was purchased from Lishuo Composite Materials Technology Co., Ltd.; montmorillonite was purchased from Wanzhao Fine Chemical Co., Ltd.; and halloysite was purchased from Jinbaixu Mineral Products Co., Ltd.

[0032] Example 1

[0033] A high-strength PC composite material comprises the following components in parts by weight: 80 parts of bisphenol A polycarbonate, 10 parts of carbon fiber, 5 parts of nano-silicate, 4 parts of intumescent flame retardant, and 1.2 parts of a silane coupling agent derivative;

[0034] The carbon fibers are modified with epoxy groups;

[0035] The silane coupling agent derivative is a copolymer obtained by a click reaction between the silane coupling agent KH571 and mercaptobenzotriazole, which occurs between mercapto groups and olefins.

[0036] The preparation method of the silane coupling agent derivative comprises the following steps:

[0037] A1, benzotriazole and succinic anhydride react at 90 ° C for 7 h under the catalysis of 4-dimethylaminopyridine to generate benzotriazole-carboxylic anhydride intermediate;

[0038] A2, hydrolyzing the benzotriazole-carboxylic anhydride intermediate obtained in step A1 with a hydrochloric acid solution to obtain carboxybenzotriazole;

[0039] A3, condensing the carboxyl-containing benzotriazole obtained in step A2 with mercaptoethylamine using a condensing agent to generate mercaptobenzotriazole;

[0040] A4. The mercaptobenzotriazole prepared in step A3 and KH571 are reacted with each other under the photoinitiator of Irgacure 819 and UV irradiated to form a silane coupling agent derivative of KH571-mercaptobenzotriazole copolymer.

[0041] The mass ratio of benzotriazole, succinic anhydride and 4-dimethylaminopyridine in step A1 is 1:1:0.1.

[0042] In step A2, the molar ratio of the benzotriazole-carboxylic anhydride intermediate to hydrochloric acid is 1:2; and the concentration of the hydrochloric acid solution is 2M.

[0043] The condensing agent in step A3 is 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in a mass ratio of 1:0.7; the mass ratio of carboxybenzotriazole, mercaptoethylamine, and condensing agent is 1:0.4:1.8.

[0044] The mass ratio of benzotriazole-SH, KH571, and Irgacure 819 in step A4 is 1:1:0.01.

[0045] The carbon fiber is chopped carbon fiber with a length of 100-300 μm and a diameter of 5-8 μm.

[0046] The nano silicate is montmorillonite with a particle size of 20-50 nm.

[0047] The intumescent flame retardant is ammonium polyphosphate and melamine cyanurate in a mass ratio of 2.5:1.

[0048] The method for preparing the high-strength PC composite material comprises the following steps:

[0049] (1) The carbon fibers were immersed in an epichlorohydrin / acetone solution with a volume ratio of 1:5, reacted at 80°C for 4 hours, mixed with nano-silicate and a silane coupling agent derivative, ultrasonically dispersed for 50 minutes, and UV-irradiated for 4 minutes to form a premix;

[0050] (2) melt-blending bisphenol A polycarbonate, premix, and intumescent flame retardant at 265° C.;

[0051] (3) PC composite materials were obtained by extrusion and granulation.

[0052] Comparative Example 1: High carbon fiber content composite material is provided:

[0053] Example 2

[0054] A high-strength PC composite material comprises the following components in parts by weight: 70 parts of bisphenol A polycarbonate, 15 parts of carbon fiber, 3 parts of nano-silicate, 3 parts of intumescent flame retardant, and 0.5 parts of a silane coupling agent derivative;

[0055] The carbon fibers are modified with epoxy groups;

[0056] The silane coupling agent derivative is a copolymer obtained by a click reaction between the silane coupling agent KH571 and mercaptobenzotriazole, which occurs between mercapto groups and olefins.

[0057] The preparation method of the silane coupling agent derivative comprises the following steps:

[0058] A1, benzotriazole and succinic anhydride react at 80 ° C for 6 h under the catalysis of 4-dimethylaminopyridine to generate benzotriazole-carboxylic anhydride intermediate;

[0059] A2, hydrolyzing the benzotriazole-carboxylic anhydride intermediate obtained in step A1 with a hydrochloric acid solution to obtain carboxybenzotriazole;

[0060] A3, condensing the carboxyl-containing benzotriazole obtained in step A2 with mercaptoethylamine using a condensing agent to generate mercaptobenzotriazole;

[0061] A4. The mercaptobenzotriazole prepared in step A3 and KH571 are reacted with each other under the photoinitiator of Irgacure 819 and UV irradiated to form a silane coupling agent derivative of KH571-mercaptobenzotriazole copolymer.

[0062] The mass ratio of benzotriazole, succinic anhydride and 4-dimethylaminopyridine in step A1 is 1:0.85:0.05.

[0063] In step A2, the molar ratio of the benzotriazole-carboxylic anhydride intermediate to hydrochloric acid is 1:1.5; and the concentration of the hydrochloric acid solution is 1M.

[0064] The condensing agent in step A3 is 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in a mass ratio of 0.85:0.6; the mass ratio of carboxybenzotriazole, mercaptoethylamine, and condensing agent is 1:035:1.6.

[0065] The mass ratio of benzotriazole-SH, KH571, and Irgacure 819 in step A4 is 1:0.8:0.005.

[0066] The carbon fiber is chopped carbon fiber with a length of 100-300 μm and a diameter of 5-8 μm.

[0067] The nano silicate is montmorillonite with a particle size of 20-50 nm.

[0068] The intumescent flame retardant is ammonium polyphosphate and melamine cyanurate in a mass ratio of 2-3:1.

[0069] The method for preparing the high-strength PC composite material comprises the following steps:

[0070] (1) The carbon fibers were immersed in an epichlorohydrin / acetone solution with a volume ratio of 1:4, reacted at 70°C for 3 hours, mixed with nano-silicate and silane coupling agent derivatives, ultrasonically dispersed for 30 minutes, and UV-irradiated for 3 minutes to form a premix;

[0071] (2) melt-blending bisphenol A polycarbonate, premix, and intumescent flame retardant at 250° C.;

[0072] (3) PC composite materials were obtained by extrusion and granulation.

[0073] Comparative Example 1: A composite material with a high flame retardant ratio is provided:

[0074] Example 3

[0075] A high-strength PC composite material comprises the following components in parts by weight: 70 parts of bisphenol A polycarbonate, 5 parts of carbon fiber, 3 parts of nano-silicate, 6 parts of intumescent flame retardant and 0.5 parts of silane coupling agent derivative;

[0076] The carbon fibers are modified with epoxy groups;

[0077] The silane coupling agent derivative is a copolymer obtained by a click reaction between the silane coupling agent KH571 and mercaptobenzotriazole, which occurs between mercapto groups and olefins.

[0078] The preparation method of the silane coupling agent derivative comprises the following steps:

[0079] A1, benzotriazole and succinic anhydride react at 100 ° C for 8 h under the catalysis of 4-dimethylaminopyridine to generate benzotriazole-carboxylic anhydride intermediate;

[0080] A2, hydrolyzing the benzotriazole-carboxylic anhydride intermediate obtained in step A1 with a hydrochloric acid solution to obtain carboxybenzotriazole;

[0081] A3, condensing the carboxyl-containing benzotriazole obtained in step A2 with mercaptoethylamine using a condensing agent to generate mercaptobenzotriazole;

[0082] A4. The mercaptobenzotriazole prepared in step A3 and KH571 are reacted with each other under the photoinitiator of Irgacure 819 and UV irradiated to form a silane coupling agent derivative of KH571-mercaptobenzotriazole copolymer.

[0083] The mass ratio of benzotriazole, succinic anhydride and 4-dimethylaminopyridine in step A1 is 1:1.2:0.15.

[0084] In step A2, the molar ratio of the benzotriazole-carboxylic anhydride intermediate to hydrochloric acid is 1:2.5; and the concentration of the hydrochloric acid solution is 3M.

[0085] The condensing agent in step A3 is 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in a mass ratio of 1.1:0.8; the mass ratio of carboxybenzotriazole, mercaptoethylamine, and condensing agent is 1:0.45:2.0.

[0086] The mass ratio of benzotriazole-SH, KH571, and Irgacure 819 in step A4 is 1:1.2:-0.02.

[0087] The carbon fiber is chopped carbon fiber with a length of 100-300 μm and a diameter of 5-8 μm.

[0088] The nano-silicate is halloysite, and the particle size is 20-50 nm.

[0089] The intumescent flame retardant is ammonium polyphosphate and melamine cyanurate in a mass ratio of 3:1.

[0090] The method for preparing the high-strength PC composite material comprises the following steps:

[0091] (1) The carbon fibers were immersed in an epichlorohydrin / acetone solution with a volume ratio of 1:6, reacted at 90°C for 5 hours, mixed with nano-silicate and silane coupling agent derivatives, ultrasonically dispersed for 60 minutes, and UV-irradiated for 5 minutes to form a premix;

[0092] (2) melt-blending bisphenol A polycarbonate, premix, and intumescent flame retardant at 280° C.;

[0093] (3) PC composite materials were obtained by extrusion and granulation.

[0094] Comparative Example 1: A high-proportion silane coupling agent derivative composite material is provided:

[0095] Example 4

[0096] A high-strength PC composite material comprises the following components in parts by weight: 80 parts of bisphenol A polycarbonate, 5 parts of carbon fiber, 3 parts of nano-silicate, 3 parts of intumescent flame retardant, and 2 parts of silane coupling agent derivative;

[0097] The carbon fibers are modified with epoxy groups;

[0098] The silane coupling agent derivative is a copolymer obtained by a click reaction between the silane coupling agent KH571 and mercaptobenzotriazole, which occurs between mercapto groups and olefins.

[0099] The preparation method of the silane coupling agent derivative comprises the following steps:

[0100] A1, benzotriazole and succinic anhydride react at 90 ° C for 6 h under the catalysis of 4-dimethylaminopyridine to generate benzotriazole-carboxylic anhydride intermediate;

[0101] A2, hydrolyzing the benzotriazole-carboxylic anhydride intermediate obtained in step A1 with a hydrochloric acid solution to obtain carboxybenzotriazole;

[0102] A3, condensing the carboxyl-containing benzotriazole obtained in step A2 with mercaptoethylamine using a condensing agent to generate mercaptobenzotriazole;

[0103] A4. The mercaptobenzotriazole prepared in step A3 and KH571 are reacted with each other under the photoinitiator of Irgacure 819 and UV irradiated to form a silane coupling agent derivative of KH571-mercaptobenzotriazole copolymer.

[0104] The mass ratio of benzotriazole, succinic anhydride and 4-dimethylaminopyridine in step A1 is 1:0.9:0.1.

[0105] In step A2, the molar ratio of the benzotriazole-carboxylic anhydride intermediate to hydrochloric acid is 1:2; and the concentration of the hydrochloric acid solution is 3M.

[0106] The condensing agent in step A3 is 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in a mass ratio of 1:0.8; the mass ratio of carboxybenzotriazole, mercaptoethylamine, and condensing agent is 1:035:2.

[0107] The mass ratio of benzotriazole-SH, KH571, and Irgacure 819 in step A4 is 1:0.8:0.02.

[0108] The carbon fiber is chopped carbon fiber with a length of 100-300 μm and a diameter of 5-8 μm.

[0109] The nano-silicate is halloysite, and the particle size is 20-50 nm.

[0110] The intumescent flame retardant is ammonium polyphosphate and melamine cyanurate in a mass ratio of 2:1.

[0111] The method for preparing the high-strength PC composite material comprises the following steps:

[0112] (1) The carbon fibers were immersed in an epichlorohydrin / acetone solution with a volume ratio of 1:5, reacted at 90°C for 5 hours, mixed with nano-silicate and silane coupling agent derivatives, ultrasonically dispersed for 30 minutes, and UV-irradiated for 5 minutes to form a premix;

[0113] (2) melt-blending bisphenol A polycarbonate, premix, and intumescent flame retardant at 260° C.;

[0114] (3) PC composite materials were obtained by extrusion and granulation.

[0115] Comparative Example 1

[0116] On the basis of Example 1, no silane coupling agent derivative was prepared, and equal amounts of silane coupling agent KH571 and benzotriazole were directly added. The rest remained the same as Example 1.

[0117] Comparative Example 2

[0118] On the basis of Example 1, the silane coupling agent K571 was replaced by the silane coupling agent K570, and the rest remained the same as Example 1.

[0119] Comparative Example 3

[0120] On the basis of Example 1, no carbon fiber was added, the addition amount of nano-silicate was changed to 15 parts by weight, and the rest remained the same as Example 1.

[0121] Comparative Example 4

[0122] On the basis of Example 1, no nano-silicate was added, the added amount of carbon fiber was changed to 15 parts by weight, and the rest remained the same as Example 1.

[0123] Comparative Example 5

[0124] On the basis of Example 1, the flame retardant was changed to decabromodiphenylethane, and the rest remained the same as Example 1.

[0125] Performance testing:

[0126] Tensile strength: tested according to ASTM D638 standard, tensile speed is 50mm / min;

[0127] Impact strength: tested according to ASTM D256 standard;

[0128] Flame retardant performance test: According to the UL-94-2009 test standard, the sample size is 127×12.7×1.6cm 3， Tested for UL94 rating and LOI value.

[0129]

[0130] The test results show that in Comparative Example 1, the silane coupling agent derivative is not prepared, and the strength and flame retardancy of the PC composite material are significantly reduced, which verifies the interface strengthening effect of the silane coupling agent derivative; in Comparative Example 2, KH570 is used instead of KH571, and an effective click reaction cannot be achieved, and the flame retardancy is reduced; Comparative Example 3 proves that short-cut nanocarbon fibers are the core of increasing the strength of PC composite materials. After not adding carbon fibers, the tensile strength drops to 53MPa and the impact strength drops to 19kJ / m 2 ; Comparative Example 4 verifies the role of nanosilicate in further improving the strength of the composite material, and is also crucial to the flame retardant effect; Comparative Example 5 (decabromodiphenyl ethane): Although the UL-94 grade reaches V-0, the LOI is only 29%, and the impact strength is low, reflecting the environmental and mechanical defects of halogen flame retardants.

[0131] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any indirect modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high-strength PC composite material, characterized by: The invention comprises the following components in parts by weight: 70-90 parts of bisphenol A polycarbonate, 5-15 parts of carbon fiber, 3-8 parts of nano-silicate, 3-6 parts of intumescent flame retardant and 0.5-2 parts of silane coupling agent derivative; The carbon fibers are modified with epoxy groups; The silane coupling agent derivative is a copolymer obtained by a click reaction between the silane coupling agent KH571 and mercaptobenzotriazole, which occurs between mercapto groups and olefins.

2. The high-strength PC composite material according to claim 1, characterized in that: The preparation method of the silane coupling agent derivative comprises the following steps: A1, benzotriazole and succinic anhydride react at 80-100°C for 6-8h under the catalysis of 4-dimethylaminopyridine to generate a benzotriazole-carboxylic anhydride intermediate; A2, hydrolyzing the benzotriazole-carboxylic anhydride intermediate obtained in step A1 with a hydrochloric acid solution to obtain carboxybenzotriazole; A3, condensing the carboxyl-containing benzotriazole obtained in step A2 with mercaptoethylamine using a condensing agent to generate mercaptobenzotriazole; A4. The mercaptobenzotriazole prepared in step A3 and KH571 are reacted with each other under the photoinitiator of Irgacure 819 and UV irradiated to form a silane coupling agent derivative of KH571-mercaptobenzotriazole copolymer.

3. The high-strength PC composite material according to claim 2, characterized in that: The mass ratio of benzotriazole, succinic anhydride and 4-dimethylaminopyridine in step A1 is 1:0.85-1.2:0.05-0.

15.

4. The high-strength PC composite material according to claim 2, characterized in that: In step A2, the molar ratio of the benzotriazole-carboxylic anhydride intermediate to hydrochloric acid is 1:1.5-2.5; and the concentration of the hydrochloric acid solution is 1-3M.

5. The high-strength PC composite material according to claim 1, characterized in that: The condensing agent in step A3 is 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in a mass ratio of 0.85-1.1:0.6-0.8; the mass ratio of carboxybenzotriazole, mercaptoethylamine, and condensing agent is 1:035-0.45:1.6-2.

0.

6. The high-strength PC composite material according to claim 2, characterized in that: The mass ratio of benzotriazole-SH, KH571, and Irgacure 819 in step A4 is 1:0.8-1.2:0.005-0.

02.

7. The high-strength PC composite material according to claim 1, characterized in that: The carbon fiber is chopped carbon fiber with a length of 100-300 μm and a diameter of 5-8 μm.

8. The high-strength PC composite material according to claim 1, characterized in that: The nano-silicate is montmorillonite or halloysite, and has a particle size of 20-50 nm.

9. The high-strength PC composite material according to claim 1, characterized in that: The intumescent flame retardant is ammonium polyphosphate and melamine cyanurate in a mass ratio of 2-3:

1.

10. A method for preparing the high-strength PC composite material according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Immersing carbon fiber in an epichlorohydrin / acetone solution with a volume ratio of 1:4-6, reacting at 70-90° C. for 3-5 hours, mixing with nano-silicate and silane coupling agent derivatives, ultrasonically dispersing, and UV irradiating to form a premix; (2) melt-blending bisphenol A polycarbonate, premix, and intumescent flame retardant at 250-280° C.; (3) PC composite materials were obtained by extrusion and granulation.

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