High-strength flame-retardant polycarbonate plastic and preparation method thereof

Abstract

The invention belongs to the technical field of polycarbonate materials, and particularly discloses a high-strength flame-retardant polycarbonate plastic and a preparation method thereof. The high-strength flame-retardant polycarbonate plastic comprises the following components in parts by weight: 60-80 parts of polycarbonate, 5-10 parts of a flame retardant, 0.1-2 parts of a dispersing agent, 0.1-2 parts of an antioxidant, 3-8 parts of a reinforcing agent and 2-6 parts of a toughening agent, a preparation process of the flame retardant comprises the following steps: adding 1, 10-phenanthroline-4, 7-diamine and triethylamine into dichloromethane, cooling to-5 to 5 DEG C, adding a dichloromethane solution of a compound A in an inert gas atmosphere, stirring to react, and purifying a reaction solution to obtain the flame retardant. The polycarbonate plastic prepared by the invention has excellent mechanical property and flame retardant property.

Description

Technical Field

[0001] The present invention belongs to the technical field of polycarbonate materials, and particularly relates to a high-strength flame-retardant polycarbonate plastic and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) is a type of high molecular polymer containing carbonate groups in its molecular chain. The alternating structure of flexible carbonate bonds and rigid arylalkylene groups in its macromolecular chain endows it with characteristics such as light weight, impact resistance, good transparency, excellent dielectric properties, heat resistance, and cold resistance, and it is widely used in fields such as construction, medical devices, electronic appliances, optical devices, automobiles, and aerospace.

[0003] With the increasingly strict safety standards and the continuous expansion of the material application environment, higher requirements are put forward for the flame-retardant performance of polycarbonate materials. Usually, flame retardants need to be introduced to achieve an ideal flame-retardant effect. There are many types of conventional flame retardants for polycarbonate, but they all have some disadvantages. Although traditional brominated flame retardants have high flame-retardant efficiency, they produce thick smoke containing carcinogens when burning; although low-molecular-weight phosphate ester flame retardants are halogen-free and environmentally friendly, they are volatile and cause deterioration of the heat resistance of the matrix; although sulfonate flame retardants can promote carbon formation and maintain transparency, they are not hydrolysis-resistant and are prone to flame-retardant failure. At the same time, the introduction of conventional flame retardants often leads to a decrease in key mechanical indexes such as the impact strength and tensile properties of the material. Therefore, it is of great significance to develop polycarbonate materials with both high flame-retardant performance and excellent mechanical properties. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the primary object of the present invention is to provide a high-strength flame-retardant polycarbonate plastic, which has excellent flame-retardant performance and mechanical properties.

[0005] Another object of the present invention is to provide a preparation method of the above high-strength flame-retardant polycarbonate plastic, and this preparation method has a simple process and can be mass-produced.

[0006] The object of the present invention is achieved by adopting the following technical solutions: A high-strength flame-retardant polycarbonate plastic, the high-strength flame-retardant polycarbonate plastic comprises by weight: 60 - 80 parts of polycarbonate, 5 - 10 parts of flame retardant, 0.1 - 2 parts of dispersant, 0.1 - 2 parts of antioxidant, 3 - 8 parts of reinforcing agent, 2 - 6 parts of toughening agent; The preparation process of the flame retardant is as follows: Add 1,10-phenanthroline-4,7-diamine and triethylamine to dichloromethane, cool to -5 - 5 °C, and then add a dichloromethane solution of compound A under an inert gas atmosphere, stir and react, and the reaction solution is obtained after purification treatment.

[0007] Preferably, the dosage ratio of 1,10-phenanthroline-4,7-diamine, triethylamine, dichloromethane and compound A is 0.1 mol: (25 - 35) mL: (250 - 300) mL: (0.2 - 0.25) mol; the stirring reaction time is 12 - 18 h.

[0008] Preferably, the preparation process of the enhancer is as follows: (1) Dispersing hydroxyapatite in acetone, adding toluene-2,4-diisocyanate and stannous octoate, reacting under heating conditions, and obtaining isocyanated hydroxyapatite after purification treatment; (2) Dispersing the isocyanated hydroxyapatite in ethyl acetate, adding 3-mercaptopropanol, reacting under heating conditions, and obtaining mercapto-functionalized hydroxyapatite after purification treatment; (3) Adding the mercapto-functionalized hydroxyapatite, allyl methyl carbonate and photoinitiator to tetrahydrofuran, reacting under an inert gas atmosphere and ultraviolet lamp irradiation, and obtaining the product after purification treatment.

[0009] Preferably, in step (1), the dosage ratio of hydroxyapatite, toluene diisocyanate, stannous octoate and acetone is 1 g: (1 - 2) g: (0.003 - 0.006) g: (50 - 75) mL; the heating temperature is 50 - 75 °C, and the reaction time is 4 - 8 h.

[0010] Preferably, in step (2), the dosage ratio of isocyanated hydroxyapatite, 3-mercaptopropanol and ethyl acetate is 1 g: (3 - 5) g: (50 - 75) mL; the heating temperature is 75 - 85 °C, and the reaction time is 3 - 8 h.

[0011] Preferably, in step (3), the dosage ratio of mercapto-functionalized hydroxyapatite, allyl methyl carbonate, photoinitiator and tetrahydrofuran is 1 g: (0.6 - 1.2) g: (0.015 - 0.03) g: (50 - 75) mL; the photoinitiator is benzoin dimethyl ether; the reaction time is 5 - 10 h.

[0012] Preferably, the polycarbonate is bisphenol A polycarbonate, and the melt index under the test conditions of 300 °C and 1.2 kg is 10 - 40 g / 10 min; the antioxidant is at least one of antioxidant 1010 and antioxidant 1076; the dispersant is at least one of monoglyceryl stearate and ethylene bisstearamide; the toughening agent is at least one of styrene-grafted maleic anhydride and methyl methacrylate-butadiene-styrene copolymer.

[0013] The preparation method of the above high-strength flame-retardant polycarbonate plastic is as follows: according to the above weight parts, polycarbonate, flame retardant, dispersant, antioxidant, reinforcing agent and toughening agent are stirred and mixed to obtain a mixture; the mixture is added into a twin-screw extruder, melted, extruded and granulated to obtain the high-strength flame-retardant polycarbonate plastic.

[0014] Preferably, the rotation speed of the stirring and mixing is 800 - 1200 rpm, and the time is 5 - 15 min.

[0015] Preferably, the temperature range of each region of the twin-screw extruder is 200 - 260 °C, and the main machine rotation speed is 300 - 850 rpm. The present invention has the following effects compared with the prior art: 1. The present invention provides a high-strength flame-retardant polycarbonate plastic, which includes raw materials such as polycarbonate and flame retardant. This flame retardant can significantly improve the flame retardancy of polycarbonate through dual mechanisms of gas-phase flame retardancy (phosphorus-nitrogen synergistically generating free radical quenching effect) and condensed-phase flame retardancy (catalyzing carbon formation to form a heat-insulating layer). In addition, the ester group structure in the flame retardant molecule can improve its compatibility with the polycarbonate matrix and enhance its dispersibility; the phenanthroline rigid skeleton in the flame retardant molecule can not only enhance the strength of the carbon layer but also assist in improving the mechanical properties of the polycarbonate material.

[0016] 2. In the raw materials of the high-strength flame-retardant polycarbonate plastic of the present invention, hydroxyapatite with surface-grafted carbonate groups is also added as a reinforcing agent, which significantly improves the mechanical properties of the polycarbonate material. On the one hand, the introduction of carbonate groups can not only effectively prevent the agglomeration of hydroxyapatite, but also the structural similarity of carbonate groups with the matrix can significantly improve the compatibility between the reinforcing agent and the polycarbonate matrix; on the other hand, the urethane groups generated during the reaction can form hydrogen bond networks with the polycarbonate molecular chains, further enhancing the interfacial interaction. The synergistic effect of the two effectively improves the dispersibility of the reinforcing agent in the matrix and the interfacial binding force, thereby further improving the mechanical properties of the polycarbonate material. Description of the Drawings

[0017] Figure 1 It is the FT-IR diagram of the reinforcing agent and hydroxyapatite prepared in Example 1 of the present invention. Detailed Embodiments

[0018] The following further describes the technical solutions of the present invention in combination with specific embodiments. However, those skilled in the art should understand that the following embodiments are only used to illustrate the present invention and should not be regarded as a limitation of the present invention. The specific conditions not specified in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, unless otherwise specified, are all conventional products obtained through commercial channels.

[0019] The particle size of hydroxyapatite used in the present invention is 200 nm; the polycarbonate is bisphenol A polycarbonate, the melt index of which is 20 g / 10 min under the test conditions of 300° C. and 1.2 kg, purchased from Sigma-Aldrich; styrene grafted maleic anhydride is purchased from BASF, Germany; and methyl methacrylate-butadiene-styrene copolymer is purchased from Kabuda Chemical.

[0020] Example 1 A high-strength flame-retardant polycarbonate plastic comprises the following raw materials, measured by weight: 70 parts of polycarbonate, 8 parts of flame retardant, 1 part of stearic acid monoglyceride, 1 part of antioxidant 1010, 5 parts of reinforcing agent, and 4 parts of styrene-grafted maleic anhydride.

[0021] The preparation process of the above flame retardant is as follows: According to the dosage ratio of 1,10-phenanthroline-4,7-diamine, triethylamine, dichloromethane and compound A of 0.1 mol:30 mL:280 mL:0.22 mol, 1,10-phenanthroline-4,7-diamine and triethylamine were added into dichloromethane to fully dissolve, cooled to 0 °C, and then a dichloromethane solution of compound A (CAS: 5381-98-6) was added dropwise under nitrogen protection, and the mixture was stirred and reacted at room temperature for 15 hours; the reaction solution was concentrated and purified by silica gel chromatography column (silica gel 300-400 mesh), the eluate was collected and the solvent was removed by rotary evaporation, and finally vacuum dried with P2O5 to obtain a flame retardant.

[0022] The preparation process of the above-mentioned enhancer is as follows: (1) According to the amount ratio of hydroxyapatite, toluene diisocyanate, stannous octoate and acetone of 1 g:1.5 g:0.004 g:60 mL, hydroxyapatite is dispersed in acetone, toluene diisocyanate and stannous octoate are added, and the mixture is reacted at 60 °C for 6 h. After the reaction is completed, the mixture is filtered, and the collected crude product is washed three times with acetone and dried to obtain isocyanate hydroxyapatite. (2) The isocyanate hydroxyapatite, 3-mercaptopropanol and ethyl acetate were used in a ratio of 1 g:4 g:65 mL. The isocyanate hydroxyapatite was ultrasonically dispersed in ethyl acetate, 3-mercaptopropanol was added, and the mixture was reacted at 80 °C for 5 h. After the reaction was completed, the mixture was filtered, and the collected crude product was washed once with ethyl acetate and ethanol, and then dried in vacuo to obtain mercapto hydroxyapatite. (3) According to the dosage ratio of mercapto-hydroxyapatite, allyl methyl carbonate, benzoin dimethyl ether and tetrahydrofuran of 1 g: 0.9 g: 0.02 g: 60 mL, mercapto-hydroxyapatite, allyl methyl carbonate and benzoin dimethyl ether (photoinitiator) were added to tetrahydrofuran, and the reaction was carried out for 8 h under nitrogen protection and ultraviolet lamp irradiation; after the reaction was completed, filtration was carried out, and the collected crude product was washed once with tetrahydrofuran and ethanol respectively, and then dried in vacuum to obtain the enhancer.

[0023] The FT-IR spectra of hydroxyapatite and the above-prepared enhancer are as Figure 1 shown, Figure 1 in which curve a corresponds to hydroxyapatite and curve b corresponds to the enhancer. In curve a, the stretching vibration at 3420 cm -1 is attributed to the stretching vibration of -OH. The hydroxyl peak at 3420 cm -1 in curve b disappears, and at the same time, the stretching vibration peak of N-H in the carbamate group appears at 3340 cm -1 , the stretching vibration peak of C=O appears at 1690 cm -1 , and the characteristic peak of C=O in the carbonate group appears at 1747 cm -1 , indicating the successful acquisition of the enhancer.

[0024] This example also provides a preparation method of the above high-strength flame-retardant polycarbonate plastic, and the specific steps are as follows: According to the above weight parts, polycarbonate, flame retardant, monoglyceryl stearate, antioxidant 1010, enhancer and styrene-grafted maleic anhydride were added to a high-speed mixer and mixed at a speed of 1000 rpm for 10 min to obtain a mixture; the mixture was added to a twin-screw extruder, melted and extruded into pellets. The temperatures of each section of the twin-screw extruder were: the first zone 200 - 220 °C, the second zone 220 - 240 °C, the third zone 240 - 250 °C, the fourth zone 250 - 260 °C, and the main machine speed was 500 rpm, then the high-strength flame-retardant polycarbonate plastic could be obtained.

[0025] Example 2 A high-strength flame-retardant polycarbonate plastic, by weight, comprises the following raw materials: 60 parts of polycarbonate, 5 parts of flame retardant, 0.1 part of ethylene bisstearamide, 0.1 part of antioxidant 1076, 3 parts of enhancer, 1 part of styrene-grafted maleic anhydride, and 1 part of methyl methacrylate-butadiene-styrene copolymer.

[0026] The preparation process of the above flame retardant is as follows: According to the dosage ratio of 1,10-phenanthroline-4,7-diamine, triethylamine, dichloromethane and compound A of 0.1 mol: 25 mL: 250 mL: 0.2 mol, 1,10-phenanthroline-4,7-diamine and triethylamine were added to dichloromethane and fully dissolved. After cooling to -5 °C, under nitrogen protection, a dichloromethane solution of compound A (CAS: 5381-98-6) was added dropwise, and the reaction was stirred at room temperature for 12 h; the reaction solution was concentrated and purified by silica gel chromatography column (silica gel 300-400 mesh), the eluate was collected and the solvent was removed by rotary evaporation, and finally dried under vacuum with P2O5 to obtain the flame retardant.

[0027] The preparation process of the above-mentioned reinforcing agent is as follows: (1) According to the dosage ratio of hydroxyapatite, toluene diisocyanate, stannous octoate and acetone of 1 g: 1 g: 0.003 g: 50 mL, hydroxyapatite was dispersed in acetone, and then toluene diisocyanate and stannous octoate were added, and the reaction was carried out at 50 °C for 8 h; after the reaction was completed, filtration was carried out, and the collected crude product was washed three times with acetone and dried to obtain isocyanated hydroxyapatite; (2) According to the dosage ratio of isocyanated hydroxyapatite, 3-mercaptopropanol and ethyl acetate of 1 g: 3 g: 50 mL, the above-mentioned isocyanated hydroxyapatite was ultrasonically dispersed in ethyl acetate, 3-mercaptopropanol was added, and the reaction was carried out at 85 °C for 3 h; after the reaction was completed, filtration was carried out, and the collected crude product was washed once with ethyl acetate and ethanol in sequence and dried under vacuum to obtain mercapto-functionalized hydroxyapatite; (3) According to the dosage ratio of mercapto-functionalized hydroxyapatite, allyl methyl carbonate, benzoin dimethyl ether and tetrahydrofuran of 1 g: 0.6 g: 0.0015 g: 50 mL, mercapto-functionalized hydroxyapatite, allyl methyl carbonate and benzoin dimethyl ether (photoinitiator) were added to tetrahydrofuran, and the reaction was carried out under nitrogen protection and ultraviolet lamp irradiation for 5 h; after the reaction was completed, filtration was carried out, and the collected crude product was washed once with tetrahydrofuran and ethanol in sequence and dried under vacuum to obtain the reinforcing agent.

[0028] This example also provides a preparation method of the above-mentioned high-strength flame-retardant polycarbonate plastic, and the specific steps are as follows: According to the above weight parts, polycarbonate, flame retardant, ethylene bisstearamide, antioxidant 1076, reinforcing agent and methyl methacrylate-butadiene-styrene copolymer were added to a high-speed mixer and mixed at a speed of 800 rpm for 15 min to obtain a mixture; the mixture was added to a twin-screw extruder, melted and extruded into pellets. The temperatures of each section of the twin-screw extruder were: zone 1 200-220 °C, zone 2 220-240 °C, zone 3 240-250 °C, zone 4 250-260 °C, and the main machine speed was 300 rpm, and the high-strength flame-retardant polycarbonate plastic could be obtained.

[0029] Example 3 A high-strength flame-retardant polycarbonate plastic, by weight, comprises the following raw materials: 80 parts of polycarbonate, 10 parts of flame retardant, 1 part of monoglyceryl stearate, 1 part of ethylene bisstearamide, 1 part of antioxidant 1010, 1 part of antioxidant 1076, 8 parts of reinforcing agent, and 6 parts of methyl methacrylate-butadiene-styrene copolymer.

[0030] The preparation process of the above flame retardant is as follows: According to the dosage ratio of 1,10-phenanthroline-4,7-diamine, triethylamine, dichloromethane and compound A of 0.1 mol: 35 mL: 300 mL: 0.25 mol, add 1,10-phenanthroline-4,7-diamine and triethylamine into dichloromethane and dissolve them fully, then cool to 5 °C. Under nitrogen protection, dropwise add the dichloromethane solution of compound A (CAS: 5381-98-6), and stir and react at room temperature for 18 h; concentrate the reaction solution, purify it by silica gel chromatography column (silica gel 300 - 400 mesh), collect the eluate and rotary evaporate to remove the solvent, and finally dry it under vacuum with P2O5 to obtain the flame retardant.

[0031] The preparation process of the above reinforcing agent is as follows: (1) According to the dosage ratio of hydroxyapatite, toluene diisocyanate, stannous octoate and acetone of 1 g: 2 g: 0.006 g: 75 mL, disperse hydroxyapatite in acetone, then add toluene diisocyanate and stannous octoate, and react at 75 °C for 4 h; after the reaction ends, filter, wash the collected crude product with acetone three times, and dry it to obtain isocyanated hydroxyapatite; (2) According to the dosage ratio of isocyanated hydroxyapatite, 3-mercaptopropanol and ethyl acetate of 1 g: 5 g: 75 mL, ultrasonically disperse the above isocyanated hydroxyapatite in ethyl acetate, add 3-mercaptopropanol, and react at 75 °C for 8 h; after the reaction ends, filter, wash the collected crude product with ethyl acetate and ethanol once respectively, and dry it under vacuum to obtain mercapto-functionalized hydroxyapatite; (3) According to the dosage ratio of mercapto-functionalized hydroxyapatite, allyl methyl carbonate, benzoin dimethyl ether and tetrahydrofuran of 1 g: 1.2 g: 0.03 g: 75 mL, add mercapto-functionalized hydroxyapatite, allyl methyl carbonate and benzoin dimethyl ether (photoinitiator) into tetrahydrofuran, and react under nitrogen protection and ultraviolet lamp irradiation for 10 h; after the reaction ends, filter, wash the collected crude product with tetrahydrofuran and ethanol once respectively, and dry it under vacuum to obtain the reinforcing agent.

[0032] This example also provides a preparation method of the above high-strength flame-retardant polycarbonate plastic, and the specific steps are as follows: Weigh each raw material according to the above weight parts. Then, add polycarbonate, flame retardant, ethylene bisstearamide, antioxidant 1010, antioxidant 1076, reinforcing agent, and methyl methacrylate-butadiene-styrene copolymer into a high-speed mixer, and mix at a speed of 1200 rpm for 5 min to obtain a mixed material; add the mixed material into a twin-screw extruder, melt extrude and pelletize. The temperatures of each section of the twin-screw extruder are as follows: the first zone is 200 - 220 °C, the second zone is 220 - 240 °C, the third zone is 240 - 250 °C, the fourth zone is 250 - 260 °C, and the main machine speed is 850 rpm, then high-strength flame-retardant polycarbonate plastic can be obtained.

[0033] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, and the difference lies in that: when preparing the reinforcing agent, steps (2) and (3) are omitted, that is, isocyanated hydroxyapatite is used as the reinforcing agent.

[0034] Comparative Example 2 Comparative Example 2 is basically the same as Example 1, and the difference lies in that: the flame retardant in Example 1 is omitted.

[0035] Test Example The polycarbonate plastics prepared in Examples 1 - 3 and Comparative Examples 1 - 2 were tested for flame retardancy according to the standard UL94, and tested for tensile strength, flexural strength, and impact strength according to the standards ASTM D638, ASTM D790, and ASTM D256. The test results are shown in Table 1, and NR in Table 1 indicates no rating.

[0036] Table 1 Performance results of polycarbonate plastics obtained in Examples 1 - 3 and Comparative Examples 1 - 2 It can be seen from the test results in Table 1 that the polycarbonate plastics prepared in Examples 1 - 3 of the present invention have both excellent mechanical properties and flame retardancy, are suitable for preparing flame-retardant products, and have wide applicability.

[0037] Compared with Comparative Example 2 without adding flame retardant, the flame retardant grades of the polycarbonate plastics prepared in Examples 1 - 3 of the present invention are all V0 grade, and the mechanical property indexes do not show obvious decline. Analyzing the reasons, it can be known that the flame retardant prepared in the present invention can significantly improve the flame retardancy of polycarbonate through dual mechanisms of gas-phase flame retardancy (phosphorus-nitrogen synergistic generation of free radical quenching effect) and condensed-phase flame retardancy (catalyzing carbon formation to form an insulating layer). Secondly, the ester group structure in the flame retardant molecule can improve its compatibility with the polycarbonate matrix and enhance its dispersibility; the phenanthroline rigid skeleton in the flame retardant molecule can not only enhance the strength of the carbon layer but also assist in improving the mechanical properties of the polycarbonate material.

[0038] Compared with using isocyanated hydroxyapatite as the reinforcing agent in Comparative Example 1, the hydroxyapatite grafted with carbonate groups on the surface was used as the reinforcing agent in Examples 1 to 3 of the present invention, significantly improving the mechanical properties of the polycarbonate plastic. This is because, on the one hand, the introduction of carbonate groups can not only effectively prevent the agglomeration of hydroxyapatite, but also the structural similarity between the carbonate groups and the matrix can significantly improve the compatibility between the reinforcing agent and the polycarbonate matrix; on the other hand, the urethane groups generated during the reaction can form hydrogen bond networks with the polycarbonate molecular chains, further enhancing the interfacial interaction. The synergistic effect of the two effectively improves the dispersibility of the reinforcing agent in the matrix and the interfacial binding force, thereby further improving the mechanical properties of the polycarbonate material.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. The basic principles and main features of the present invention have been described with specific implementation schemes above. On the basis of the present invention, some modifications or replacements can be made, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the present invention claimed.

Claims

1. A high-strength flame-retardant polycarbonate plastic, characterized in that, The high-strength flame-retardant polycarbonate plastic comprises, by weight parts: 60-80 parts of polycarbonate, 5-10 parts of flame retardant, 0.1-2 parts of dispersant, 0.1-2 parts of antioxidant, 3-8 parts of reinforcing agent, and 2-6 parts of toughening agent; The preparation process of the flame retardant is as follows: Add 1,10-phenanthroline-4,7-diamine and triethylamine into dichloromethane, cool to -5 to 5 °C, and then add the dichloromethane solution of compound A under an inert gas atmosphere, stir and react, and the reaction solution is purified to obtain the product.

2. The high-strength flame-retardant polycarbonate plastic according to claim 1, wherein The dosage ratio of 1,10-phenanthroline-4,7-diamine, triethylamine, dichloromethane and compound A is 0.1 mol:(25-35) mL:(250-300) mL:(0.2-0.25) mol; the stirring reaction time is 12-18 h.

3. The high-strength flame-retardant polycarbonate plastic according to claim 1, wherein The preparation process of the reinforcing agent is as follows: (1) Disperse hydroxyapatite in acetone, add toluene-2,4-diisocyanate and stannous octoate, and react under heating conditions, and after purification, isocyanated hydroxyapatite is obtained; (2) Disperse the isocyanated hydroxyapatite in ethyl acetate, add 3-mercaptopropanol, and react under heating conditions, and after purification, mercapto hydroxyapatite is obtained; (3) Add the mercapto hydroxyapatite, allyl methyl carbonate and photoinitiator into tetrahydrofuran, and react under an inert gas atmosphere and ultraviolet lamp irradiation, and after purification, the product is obtained.

4. The high-strength flame-retardant polycarbonate plastic according to claim 3, wherein In step (1), the dosage ratio of hydroxyapatite, toluene diisocyanate, stannous octoate and acetone is 1 g:(1-2) g:(0.003-0.006) g:(50-75) mL; the heating temperature is 50-75 °C, and the reaction time is 4-8 h.

5. The high-strength flame-retardant polycarbonate plastic according to claim 3, characterized in that, In step (2), the dosage ratio of isocyanated hydroxyapatite, 3-mercaptopropanol and ethyl acetate is 1 g:(3-5) g:(50-75) mL; the heating temperature is 75-85 °C, and the reaction time is 3-8 h.

6. The high-strength flame-retardant polycarbonate plastic according to claim 3, characterized in that, In step (3), the dosage ratio of mercapto hydroxyapatite, allyl methyl carbonate, photoinitiator and tetrahydrofuran is 1 g:(0.6-1.2) g:(0.015-0.03) g:(50-75) mL; the photoinitiator is benzoin dimethyl ether; the reaction time is 5-10 h.

7. The high-strength flame-retardant polycarbonate plastic according to claim 1, characterized in that, The polycarbonate is bisphenol A polycarbonate, and the melt index under the test conditions of 300 °C and 1.2 kg is 10-40 g / 10 min; the antioxidant is at least one of antioxidant 1010 and antioxidant 1076; the dispersant is at least one of monoglyceryl stearate and ethylene bisstearamide; the toughening agent is at least one of styrene-grafted maleic anhydride and methyl methacrylate-butadiene-styrene copolymer.

8. The preparation method of the high-strength flame-retardant polycarbonate plastic according to any one of claims 1 to 7, characterized in that, According to the above weight parts, mix polycarbonate, flame retardant, dispersant, antioxidant, reinforcing agent and toughening agent by stirring to obtain a mixture; add the mixture into a twin-screw extruder, melt extrude and pelletize to obtain the high-strength flame-retardant polycarbonate plastic.

9. The preparation method of the high-strength flame-retardant polycarbonate plastic according to claim 8, wherein, The rotation speed of the stirring and mixing is 800 - 1200 rpm, and the time is 5 - 15 min.

10. The preparation method of the high-strength flame-retardant polycarbonate plastic according to claim 8, characterized in that, The temperature range of each zone of the twin - screw extruder is 200 - 260 °C, and the main machine rotation speed is 300 - 850 rpm.

Images