Fireproof flame-retardant PC / ABS material and preparation method thereof

Abstract

The invention discloses a fireproof flame-retardant PC / ABS material and a preparation method thereof, and relates to the technical field of macromolecules. When the fireproof flame-retardant PC / ABS material is prepared, hydroxylated boron nitride sequentially reacts with N, N-diethyl-3-aminopropyltrimethoxysilane and 2-chloroethanethiol, and modified boron nitride is prepared; the preparation method comprises the following steps: reacting 1H-imidazole-4, 5-dimethanol with bisphenol A and diphenyl carbonate to prepare pre-modified PC, and then reacting with 1-(chloro-methylphosphoryl) ethylene to prepare modified PC; the preparation method comprises the following steps: reacting ABS with maleic anhydride to prepare pre-modified ABS, and then reacting the pre-modified ABS with 2-o-hydroxyphenyl-4-amino-6-methoxy-1, 3, 5-triazine to prepare modified ABS; and carrying out melt blending on the modified PC, the modified ABS and the modified boron nitride to prepare the fireproof flame-retardant PC / ABS material. The fireproof flame-retardant PC / ABS material prepared by the invention has good flame retardance, ultraviolet aging resistance, antibacterial property and mechanical property.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, in particular to a fire-resistant and flame-retardant PC / ABS material and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) offers advantages such as high impact strength, creep resistance, good dimensional stability, heat resistance, transparency, and excellent dielectric properties. However, it also suffers from disadvantages such as poor processing fluidity, susceptibility to stress cracking, notch sensitivity, and poor wear resistance. Acrylonitrile / butadiene / styrene copolymer (ABS) offers good chemical resistance and moldability, but its heat and weather resistance are relatively poor. PC / ABS alloys, obtained by blending and modifying the two, offer complementary properties. Not only do the blends surpass ABS in heat resistance, impact strength, and tensile strength, but they also have lower melt viscosity than PC, resulting in better processability and less sensitivity of internal stress and impact strength to thickness. They are widely used in the electronics, automotive, and many other high-tech fields.

[0003] Polycarbonate (PC) has a certain degree of flame retardancy, with a limiting oxygen index of 25% and vertical combustion reaching V-2. However, ABS is extremely flammable, with a limiting oxygen index of only 18% and no vertical combustion rating. When PC and ABS are blended, the flame retardancy decreases with increasing ABS content. When the PC:ABS ratio is 7:3, the limiting oxygen index is only 20.6%. Therefore, PC / ABS materials need to be modified to improve their flame retardancy. Furthermore, ABS is susceptible to oxidative degradation under the influence of ultraviolet light, which reduces the material's mechanical properties. Therefore, the present invention prepares a flame-retardant PC / ABS material with excellent flame retardancy and resistance to UV aging. Summary of the Invention

[0004] The object of the present invention is to provide a fire-retardant PC / ABS material and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A fire-retardant PC / ABS material is prepared by melt-blending modified PC, modified ABS and modified boron nitride.

[0006] As an optimization, the modified PC is prepared by reacting 1H-imidazole-4,5-dimethanol with bisphenol A and diphenyl carbonate to obtain pre-modified PC, which is then reacted with 1-(chloro-methylphosphoryl)ethylene to obtain the pre-modified PC.

[0007] As an optimization, the modified ABS is prepared by reacting ABS with maleic anhydride to obtain pre-modified ABS, which is then reacted with 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine to obtain the pre-modified ABS.

[0008] As an optimization, the modified boron nitride is prepared by reacting hydroxylated boron nitride with N,N-diethyl-3-aminopropyltrimethoxysilane and 2-chloroethanethiol in sequence.

[0009] A method for preparing a fire-retardant PC / ABS material, comprising the following steps: (1) Pre-modified boron nitride, 2-chloroethanethiol, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1: (0.4-0.5): (10-15), stirred at 65-75°C and 200-300 r / min for 8-10 h, and N,N-dimethylformamide was removed by vacuum distillation. The mixture was washed with anhydrous ethanol for 2-4 times and vacuum dried at 50-60°C for 10-12 h to obtain modified boron nitride. (2) Pre-modified PC, 1-(chloro-methylphosphoryl)ethylene, sodium hydride, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1: (0.1~0.2): (0.05~0.07): (15~20), stirred at 50~60℃, 200~300r / min for 20~40min, heated to 75~85℃, stirred at 200~300r / min for 2~3h, and 5~10 times the mass of pre-modified PC was added at 0~4℃. N,N-dimethylformamide was removed by rotary evaporation, washed with anhydrous ethanol 2~4 times, and vacuum dried at 40~50℃ for 10~12h to obtain modified PC; (3) Pre-modified ABS, 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1: (0.06-0.07): (15-20), stirred at 40-50 ° C and 200-300 r / min for 10-12 h, and the solvent was removed by vacuum distillation. The mixture was washed with anhydrous ethanol 2-4 times and vacuum dried at 40-50 ° C for 10-12 h to obtain modified ABS. (4) Modified PC, modified ABS, modified boron nitride, and azobisisobutyronitrile were mixed uniformly in a mass ratio of 1: (0.4~0.45): (0.02~0.04): (0.001~0.002), added to a Haake torque rheometer, melt blended at 200~220℃, 50~60r / min for 8~10min, placed in a flat vulcanizer, preheated at 230℃ for 5min, then hot pressed at a pressure of 20MPa for 5min, and then cold pressed at 15MPa for 3min, demolded, and a fire-retardant PC / ABS material was obtained.

[0010] As an optimization, the preparation steps of the pre-modified boron nitride in step (1) are as follows: N, N-diethyl-3-aminopropyltrimethoxysilane and 98wt% ethanol aqueous solution are mixed uniformly in a mass ratio of 1: (50~100), ultrasonically dispersed for 20~30min to obtain N, N-diethyl-3-aminopropyltrimethoxysilane hydrolyzate, 15~20 times the mass of N, N-diethyl-3-aminopropyltrimethoxysilane is added to hydroxylated boron nitride, stirred at 75~85℃ and 300~500r / min for 6~8h, centrifuged at a speed of 10000~12000rpm for 10~12min, the obtained precipitate is washed 3~5 times with 98wt% ethanol aqueous solution, and vacuum dried at 50~60℃ for 10~12h to obtain pre-modified boron nitride.

[0011] As an optimization, the preparation steps of the pre-modified PC in step (2) are as follows: under a nitrogen atmosphere, 1H-imidazole-4,5-dimethanol, bisphenol A, diphenyl carbonate, and sodium hydroxide are mixed uniformly in a mass ratio of 1: (1.75~1.8): (3.4~3.6): (0.00001~0.00002), stirred and reacted at 220~240℃ and a vacuum degree of 6~10kPa for 1.5~2.5h, heated to 240~250℃ and 50~150Pa, stirred and reacted for 20~40min, cooled to room temperature, washed with anhydrous ethanol 2~4 times, and vacuum dried at 40~50℃ for 10~12h to obtain pre-modified PC.

[0012] As an optimization, the preparation steps of the pre-modified ABS in step (3) are as follows: under a nitrogen atmosphere, ABS, maleic anhydride, diisopropylbenzene peroxide, and butyl acetate are uniformly mixed in a mass ratio of 1: (0.1~0.2): (0.022~0.024): (5~10), stirred at 100~120℃ and 200~300r / min for 6~8h, cooled to room temperature, added with anhydrous ethanol 15~20 times the mass of ABS, continued stirring for 20~40min, filtered and washed with anhydrous ethanol 2~4 times, and vacuum dried at 60~80℃ for 10~12h to obtain pre-modified ABS.

[0013] As an optimization, the preparation steps of the hydroxylated boron nitride are as follows: boron nitride and 75wt% glucose aqueous solution are uniformly mixed in a mass ratio of 1:(10~12), ultrasonically dispersed for 20~30 minutes, added into a planetary ball mill at a speed of 300~400 rpm and ball milled for 10~12 hours, washed with deionized water 3~5 times, and vacuum dried at 50~60°C for 10~12 hours to obtain hydroxylated boron nitride.

[0014] As an optimization, the ABS is a general-grade ABS resin purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0015] As an optimization, the boron nitride is hexagonal boron nitride with a particle size of 80 nm, purchased from Shanghai Xiaohuang Nanotechnology Co., Ltd.

[0016] As an optimization, the reaction equation of the modified boron nitride is as follows: .

[0017] As an optimization, the reaction equation of the modified PC is as follows: .

[0018] As an optimization, the reaction equation of the modified ABS is as follows: .

[0019] Compared with the prior art, the present invention has the following beneficial effects: The present invention prepares a fireproof and flame-retardant PC / ABS material by reacting hydroxylated boron nitride with N,N-diethyl-3-aminopropyltrimethoxysilane to obtain pre-modified boron nitride; reacting the pre-modified boron nitride with 2-chloroethanethiol to obtain modified boron nitride; reacting 1H-imidazole-4,5-dimethanol with bisphenol A and diphenyl carbonate to obtain pre-modified PC; reacting the pre-modified PC with 1-(chloro-methylphosphinoyl)ethylene to obtain modified PC; reacting ABS with maleic anhydride to obtain pre-modified ABS; reacting the pre-modified ABS with 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine to obtain modified ABS; and melt-blending the modified PC, modified ABS and modified boron nitride to obtain the fireproof and flame-retardant PC / ABS material.

[0020] First, hydroxylated boron nitride was reacted with N,N-diethyl-3-aminopropyltrimethoxysilane to prepare pre-modified boron nitride; then the pre-modified boron nitride was reacted with 2-chloroethanethiol to prepare modified boron nitride; boron nitride has good mechanical properties and flame retardant properties. Surface modification of hydroxylated boron nitride with N,N-diethyl-3-aminopropyltrimethoxysilane improved the compatibility of boron nitride in PC and ABS. At the same time, tertiary amine groups were introduced into the boron nitride, which reacted with the chlorine on 2-chloroethanethiol to undergo quaternization, thereby improving the antibacterial properties of the fire-retardant PC / ABS material.

[0021] Secondly, 1H-imidazole-4,5-dimethanol is reacted with bisphenol A and diphenyl carbonate to obtain pre-modified PC; the pre-modified PC is reacted with 1-(chloro-methylphosphoryl)ethylene to obtain modified PC; 1H-imidazole-4,5-dimethanol is subjected to an ester exchange reaction with bisphenol A and diphenyl carbonate to obtain pre-modified PC. The obtained pre-modified PC contains imidazole groups, which react with 1-(chloro-methylphosphoryl)ethylene to introduce phosphorus elements and double bonds into the material. The phosphorus elements synergistically flame retardant with the nitrogen elements on the imidazole and triazine structures, thereby improving the flame retardant properties of the fire-retardant PC / ABS material; the double bonds on the modified PC react with the thiol groups on the modified boron nitride to form a thiol-ene reaction to form a cross-linked network structure, thereby improving the mechanical properties of the fire-retardant PC / ABS material.

[0022] Finally, ABS was reacted with maleic anhydride to obtain pre-modified ABS; the pre-modified ABS was reacted with 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine to obtain modified ABS; maleic anhydride was grafted onto ABS and reacted with 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine to introduce carboxyl groups and triazine UV absorbers onto ABS, thereby improving the UV aging resistance of the fire-retardant PC / ABS material. At the same time, the carboxyl groups on the modified ABS electrostatically bonded with the quaternary ammonium cations on the modified boron nitride, thereby improving the mechanical properties of the fire-retardant PC / ABS material. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Example 1: A method for preparing a fire-retardant PC / ABS material, comprising the following steps: (1) Boron nitride and 75wt% glucose aqueous solution were mixed at a mass ratio of 1:10, ultrasonically dispersed for 20 minutes, added to a planetary ball mill at a speed of 300rpm and ball milled for 10 hours, washed with deionized water 3 times, and vacuum dried at 50℃ for 10 hours to obtain hydroxylated boron nitride; N,N-diethyl-3-aminopropyltrimethoxysilane and 98wt% ethanol aqueous solution were mixed at a mass ratio of 1:50, ultrasonically dispersed for 20 minutes to obtain N,N-diethyl-3-aminopropyltrimethoxysilane hydrolyzate, and 1 mass % of N,N-diethyl-3-aminopropyltrimethoxysilane was added. 5 times of hydroxylated boron nitride, stirred at 75 ° C, 300 r / min for 6 hours, centrifuged at 10000 rpm for 10 minutes, the resulting precipitate was washed three times with 98wt% ethanol aqueous solution, and vacuum dried at 50 ° C for 10 hours to obtain pre-modified boron nitride; pre-modified boron nitride, 2-chloroethanethiol, and N, N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.4:10, stirred at 65 ° C, 200 r / min for 8 hours, and N, N-dimethylformamide was removed by vacuum distillation under reduced pressure. The precipitate was washed twice with anhydrous ethanol and vacuum dried at 50 ° C for 10 hours to obtain modified boron nitride; (2) Under nitrogen atmosphere, 1H-imidazole-4,5-dimethanol, bisphenol A, diphenyl carbonate and sodium hydroxide were mixed in a mass ratio of 1:1.75:3.4:0.00001, stirred at 220 ° C, vacuum degree of 6 kPa, reacted for 1 hour, heated to 240 ° C, 50 Pa, stirred for 20 minutes, cooled to room temperature, washed twice with anhydrous ethanol, and vacuum dried at 40 ° C for 10 hours to obtain pre-modified PC; pre-modified PC, 1-(chloro -methylphosphinoyl)ethylene, sodium hydride, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.1:0.05:15, stirred at 50°C and 200 r / min for 20 min, heated to 75°C, stirred at 200 r / min for 2 h, and then added with a saturated ammonium chloride solution 5 times the mass of the pre-modified PC at 0°C. The N,N-dimethylformamide was removed by rotary evaporation, washed twice with anhydrous ethanol, and dried in vacuo at 40°C for 10 h to obtain modified PC; (3) Under nitrogen atmosphere, ABS, maleic anhydride, diisopropylbenzene peroxide, and butyl acetate were mixed in a mass ratio of 1:0.1:0.022:5, stirred at 100 °C and 200 r / min for 6 h, cooled to room temperature, added with anhydrous ethanol 15 times the mass of ABS, and continued to stir for 20 min. Filtered and washed with anhydrous ethanol twice, and vacuum dried at 60 °C for 10 h to obtain pre-modified ABS; pre-modified ABS, 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine, and N,N-dimethylformamide were mixed in a mass ratio of 1:0.06:15, stirred at 40 °C and 200 r / min for 10 h, and the solvent was removed by vacuum distillation. The mixture was washed with anhydrous ethanol twice and vacuum dried at 40 °C for 10 h to obtain modified ABS. (4) Modified PC, modified ABS, modified boron nitride, and azobisisobutyronitrile were mixed evenly in a mass ratio of 1:0.4:0.02:0.001, added to a Haake torque rheometer, melt-blended at 200°C and 50 r / min for 8 minutes, placed in a flat vulcanizer, preheated at 230°C for 5 minutes, and then hot-pressed at a pressure of 20 MPa for 5 minutes, and then cold-pressed at 15 MPa for 3 minutes, demolded, and a fire-retardant PC / ABS material was obtained.

[0025] Example 2: A method for preparing a fire-retardant PC / ABS material, comprising the following steps: (1) Boron nitride and 75wt% glucose aqueous solution were mixed at a mass ratio of 1:11, ultrasonically dispersed for 25 minutes, added to a planetary ball mill at a speed of 350rpm and ball milled for 11 hours, washed with deionized water 4 times, and vacuum dried at 55℃ for 11 hours to obtain hydroxylated boron nitride; N,N-diethyl-3-aminopropyltrimethoxysilane and 98wt% ethanol aqueous solution were mixed at a mass ratio of 1:75, ultrasonically dispersed for 25 minutes to obtain N,N-diethyl-3-aminopropyltrimethoxysilane hydrolyzate, and 18wt% N,N-diethyl-3-aminopropyltrimethoxysilane was added. times of hydroxylated boron nitride, stirred at 80°C and 400 r / min for 7 hours, centrifuged at 11000 rpm for 11 minutes, and the resulting precipitate was washed four times with 98wt% ethanol aqueous solution and dried in vacuum at 55°C for 11 hours to obtain pre-modified boron nitride; pre-modified boron nitride, 2-chloroethanethiol, and N,N-dimethylformamide were uniformly mixed in a mass ratio of 1:0.45:13, stirred at 70°C and 250 r / min for 9 hours, and N,N-dimethylformamide was removed by reduced pressure distillation, washed three times with anhydrous ethanol, and dried in vacuum at 55°C for 11 hours to obtain modified boron nitride; (2) Under nitrogen atmosphere, 1H-imidazole-4,5-dimethanol, bisphenol A, diphenyl carbonate and sodium hydroxide were mixed in a mass ratio of 1:1.78:3.5:0.000015, stirred at 230 ° C, vacuum degree of 8 kPa, reacted for 2 h, heated to 245 ° C, 100 Pa, stirred for 30 min, cooled to room temperature, washed with anhydrous ethanol 3 times, and vacuum dried at 45 ° C for 11 h to obtain pre-modified PC; pre-modified PC, 1-(chloro -methylphosphoryl)ethylene, sodium hydride, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.15:0.06:18, stirred at 55°C and 250r / min for 30min, heated to 80°C, stirred at 250r / min for 2.5h, and then added with saturated ammonium chloride solution 8 times the mass of pre-modified PC at 2°C. The N,N-dimethylformamide was removed by rotary evaporation, washed with anhydrous ethanol 3 times, and dried in vacuo at 45°C for 11h to obtain modified PC; (3) Under nitrogen atmosphere, ABS, maleic anhydride, diisopropylbenzene peroxide, and butyl acetate were mixed in a mass ratio of 1:0.15:0.023:8, stirred at 110 ° C, 250 r / min for 7 h, cooled to room temperature, added with anhydrous ethanol 18 times the mass of ABS, and continued to stir for 30 min. Filtered and washed with anhydrous ethanol three times, and vacuum dried at 70 ° C for 11 h to obtain pre-modified ABS; pre-modified ABS, 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine, and N,N-dimethylformamide were mixed in a mass ratio of 1:0.065:18, stirred at 45 ° C, 250 r / min for 11 h, and the solvent was removed by vacuum distillation. The mixture was washed with anhydrous ethanol three times and vacuum dried at 45 ° C for 11 h to obtain modified ABS. (4) Modified PC, modified ABS, modified boron nitride, and azobisisobutyronitrile were mixed evenly in a mass ratio of 1:0.42:0.03:0.0015, added to a Haake torque rheometer, melt-blended at 210°C and 55 r / min for 9 minutes, placed in a flat vulcanizer, preheated at 230°C for 5 minutes, and then hot-pressed at a pressure of 20 MPa for 5 minutes, and then cold-pressed at 15 MPa for 3 minutes, demolded, and a fire-retardant PC / ABS material was obtained.

[0026] Example 3: A method for preparing a fire-retardant PC / ABS material, comprising the following steps: (1) Boron nitride and 75wt% glucose aqueous solution were mixed at a mass ratio of 1:12, ultrasonically dispersed for 30 minutes, added to a planetary ball mill at a speed of 400rpm and ball milled for 12 hours, washed with deionized water 5 times, and vacuum dried at 60℃ for 12 hours to obtain hydroxylated boron nitride; N,N-diethyl-3-aminopropyltrimethoxysilane and 98wt% ethanol aqueous solution were mixed at a mass ratio of 1:100, ultrasonically dispersed for 30 minutes to obtain N,N-diethyl-3-aminopropyltrimethoxysilane hydrolyzate, and N,N-diethyl-3-aminopropyltrimethoxysilane was added at a mass ratio of 2 0 times of hydroxylated boron nitride, stirring at 85 ° C, 500 r / min for 8 hours, centrifuged at 12000 rpm for 12 minutes, the resulting precipitate was washed 5 times with 98wt% ethanol aqueous solution, and vacuum dried at 60 ° C for 12 hours to obtain pre-modified boron nitride; pre-modified boron nitride, 2-chloroethanethiol, and N, N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.5:15, stirred at 75 ° C, 300 r / min for 10 hours, and N, N-dimethylformamide was removed by reduced pressure distillation, washed 4 times with anhydrous ethanol, and vacuum dried at 60 ° C for 12 hours to obtain modified boron nitride; (2) Under nitrogen atmosphere, 1H-imidazole-4,5-dimethanol, bisphenol A, diphenyl carbonate and sodium hydroxide were mixed in a mass ratio of 1:1.8:3.6:0.00002, stirred at 240 ° C, vacuum degree of 10 kPa, reacted for 2.5 h, heated to 250 ° C, 150 Pa, stirred for 40 min, cooled to room temperature, washed with anhydrous ethanol 4 times, and vacuum dried at 50 ° C for 12 h to obtain pre-modified PC; pre-modified PC, 1-( Chloro-methylphosphinoyl)ethylene, sodium hydride, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:0.2:0.07:20, stirred at 60°C and 300 r / min for 40 min, heated to 85°C and stirred at 300 r / min for 3 h, and then added with a saturated ammonium chloride solution 10 times the mass of the pre-modified PC at 4°C. The N,N-dimethylformamide was removed by rotary evaporation, washed with anhydrous ethanol 4 times, and dried in vacuo at 50°C for 12 h to obtain modified PC. (3) Under nitrogen atmosphere, ABS, maleic anhydride, diisopropylbenzene peroxide, and butyl acetate were mixed in a mass ratio of 1:0.2:0.024:10, stirred at 120°C, 300 r / min for 8 h, cooled to room temperature, added with anhydrous ethanol 20 times the mass of ABS, and continued to stir for 40 min. Filtered and washed with anhydrous ethanol 4 times, and vacuum dried at 80°C for 12 h to obtain pre-modified ABS; pre-modified ABS, 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine, and N,N-dimethylformamide were mixed in a mass ratio of 1:0.07:20, stirred at 50°C, 300 r / min for 12 h, and the solvent was removed by vacuum distillation. The mixture was washed with anhydrous ethanol 4 times and vacuum dried at 50°C for 12 h to obtain modified ABS. (4) Modified PC, modified ABS, modified boron nitride, and azobisisobutyronitrile were mixed evenly in a mass ratio of 1:0.45:0.04:0.002, added to a Haake torque rheometer, melt-blended at 220°C and 60 r / min for 10 min, placed in a flat vulcanizer, preheated at 230°C for 5 min, and then hot-pressed at a pressure of 20 MPa for 5 min, and then cold-pressed at 15 MPa for 3 min, demolded, and a fire-retardant PC / ABS material was obtained.

[0027] Comparative Example 1: The preparation method of the fire-retardant PC / ABS material of Comparative Example 1 is different from that of Example 2 in that step (1) is different. Step (1) is modified as follows: Boron nitride and 75wt% glucose aqueous solution are mixed uniformly in a mass ratio of 1:11, ultrasonically dispersed for 25 minutes, added to a planetary ball mill with a rotation speed of 350rpm and ball milled for 11 hours, washed with deionized water 4 times, and vacuum dried at 55°C for 11 hours to obtain hydroxylated boron nitride; N,N-diethyl-3-aminopropyltrimethoxysilane, 98w A 98 wt% ethanol aqueous solution was uniformly mixed at a mass ratio of 1:75, and ultrasonically dispersed for 25 minutes to obtain an N,N-diethyl-3-aminopropyltrimethoxysilane hydrolyzate. Hydroxylated boron nitride (18 times the mass of N,N-diethyl-3-aminopropyltrimethoxysilane) was added, and the mixture was stirred at 80°C and 400 rpm for 7 hours. The mixture was centrifuged at 11,000 rpm for 11 minutes. The resulting precipitate was washed four times with a 98 wt% ethanol aqueous solution and vacuum dried at 55°C for 11 hours to obtain modified boron nitride. The remaining steps were the same as in Example 2.

[0028] Comparative Example 2: The preparation method of the fire-retardant PC / ABS material of Comparative Example 2 differs from that of Example 2 in that step (1) is omitted and step (4) is modified as follows: the modified PC, modified ABS, and azobisisobutyronitrile are uniformly mixed in a mass ratio of 1:0.42:0.0015, added to a Haake torque rheometer, melt-blended at 210°C and 55 r / min for 9 minutes, placed in a flat vulcanizer, preheated at 230°C for 5 minutes, then hot-pressed at a pressure of 20 MPa for 5 minutes, and then cold-pressed at 15 MPa for 3 minutes, and demolded to obtain a fire-retardant PC / ABS material. The remaining steps are the same as those of Example 2.

[0029] Comparative Example 3: The preparation method of the fire-retardant PC / ABS material of Comparative Example 3 differs from that of Example 2 in that step (2) is modified as follows: under a nitrogen atmosphere, 1H-imidazole-4,5-dimethanol, bisphenol A, diphenyl carbonate, and sodium hydroxide are uniformly mixed in a mass ratio of 1:1.78:3.5:0.000015, stirred and reacted at 230°C and a vacuum degree of 8 kPa for 2 h, then heated to 245°C and a vacuum degree of 100 kPa, stirred and reacted for 30 min, cooled to room temperature, washed with anhydrous ethanol three times, and vacuum dried at 45°C for 11 h to obtain modified PC. The remaining steps are the same as those of Example 2.

[0030] Comparative Example 4: The preparation method of the fire-retardant PC / ABS material of Comparative Example 4 differs from that of Example 2 in that step (2) is modified as follows: bisphenol A, diphenyl carbonate, and sodium hydroxide are uniformly mixed in a mass ratio of 1:1:0.000015 under a nitrogen atmosphere, stirred and reacted at 230°C and a vacuum degree of 8 kPa for 2 h, then heated to 245°C and a vacuum degree of 100 kPa, stirred and reacted for 30 min, cooled to room temperature, washed with anhydrous ethanol three times, and vacuum dried at 45°C for 11 h to obtain modified PC. The remaining steps are the same as those of Example 2.

[0031] Comparative Example 5: The preparation method of the fire-retardant PC / ABS material of Comparative Example 5 differs from that of Example 2 in that step (3) is omitted and step (4) is modified as follows: the modified PC, ABS, and azobisisobutyronitrile are uniformly mixed in a mass ratio of 1:0.42:0.03:0.0015, added to a Haake torque rheometer, melt-blended at 210°C and 55 r / min for 9 minutes, placed in a flat vulcanizer, preheated at 230°C for 5 minutes, then hot-pressed at a pressure of 20 MPa for 5 minutes, and then cold-pressed at 15 MPa for 3 minutes, demolded, and formed to obtain the fire-retardant PC / ABS material. The remaining steps are the same as those of Example 2.

[0032] Test Example 1: Flame retardant performance test: The fire-retardant PC / ABS materials obtained in each embodiment and comparative example were made into specimens of the same size, and the limiting oxygen index was tested with reference to GB / T2406.2-2009.

[0033] The fire-retardant PC / ABS materials obtained in each embodiment and comparative example were made into 80mm×10mm×3.2mm specimens, and the specimens were subjected to a vertical combustion test with reference to GB / T2008-2021 "Horizontal and vertical methods for determination of combustion performance of plastics".

[0034] The results are shown in Table 1.

[0035] Table 1 Limiting oxygen index UL 94 rating Example 1 37.9% V-0 Example 2 38.5% V-0 Example 3 38.4% V-0 Comparative Example 1 38.4% V-0 Comparative Example 2 32.3% V-1 Comparative Example 3 28.1% V-2 Comparative Example 4 25.7% V-2 Comparative Example 5 33.6% V-1 From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 1, it can be found that the fire-retardant PC / ABS material prepared in the present invention has good flame retardant properties.

[0036] By comparison, the limiting oxygen index and UL 94 rating of Examples 1 to 3 and Comparative Example 2 indicate that hexagonal boron nitride can promote the formation of a dense carbon layer and has a layered structure, which can block oxygen during combustion, thereby improving the flame retardant properties of the fire-retardant PC / ABS material.

[0037] By comparison, the limiting oxygen index and UL 94 rating of Examples 1 to 3 and Comparative Examples 3 to 5 indicate that the imidazole group and the triazine group contain a large amount of nitrogen elements, and the pre-modified PC reacts with 1-(chloro-methylphosphoryl)ethylene to introduce phosphorus into the material. The synergistic flame retardancy of P and N further improves the flame retardant properties of the fire-retardant PC / ABS material.

[0038] Test Example 2: Tensile strength and UV aging resistance test: The specific test methods are as follows: Tensile strength test method: The fire-retardant PC / ABS materials obtained in each embodiment and the comparative example were respectively made into test specimens of 10 cm×10 mm×1 mm, and tested in accordance with GB / T1040-2006 at a tensile speed of 50 mm / min to test the tensile strength M.

[0039] Anti-ultraviolet aging performance test method: The fire-retardant PC / ABS materials obtained in each example and the comparative example were respectively made into test specimens of 10 cm × 10 mm × 1 mm, and artificial accelerated aging tests were performed with reference to GB / T16422.3 "Plastics Laboratory Light Source Exposure Test Methods Part 3: Fluorescent UV Lamp". The aging time was 120 h, and the tensile strength N was tested again, and the performance degradation rate was calculated as 1-N / M×100%.

[0040] The results are shown in Table 2.

[0041] Table 2 Tensile strength (MPa) Performance degradation rate Example 1 76.6 1.91% Example 2 77.1 1.79% Example 3 77.1 1.83% Comparative Example 1 58.3 1.95% Comparative Example 2 50.5 1.87% Comparative Example 3 63.9 1.93% Comparative Example 4 64.2 1.90% Comparative Example 5 64.7 14.23% From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 2, it can be found that the fire-retardant PC / ABS material prepared in the present invention has good mechanical properties and anti-ultraviolet aging properties.

[0042] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Examples 1 to 5, indicating that boron nitride itself has good mechanical properties. Melt blending with PC and ABS improves the mechanical properties of the material. Boron nitride is modified by introducing quaternary ammonium cations and thiol groups into the boron nitride. The quaternary ammonium cations can electrostatically bond with the carboxyl groups on the modified ABS, thereby improving the mechanical properties. At the same time, the thiol groups on 2-chloroethanethiol can react with the double bonds on the modified PC to form a thiol-ene reaction, forming a cross-linked network structure, further improving the mechanical properties of the fire-retardant PC / ABS material.

[0043] By comparison, the performance degradation rates of Examples 1 to 3 are less than that of Comparative Example 5, indicating that the pre-modified ABS reacts with 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine, and a triazine ultraviolet absorber is introduced into the ABS. Under ultraviolet light irradiation, a conjugated hydrogen bond six-membered ring can be formed, which can absorb ultraviolet light and improve the anti-ultraviolet aging performance of the fire-retardant PC / ABS material.

[0044] Test Example 3: Antibacterial testing: The antibacterial rate against Escherichia coli and Staphylococcus aureus was tested according to GB / T31402-2023 "Determination of antibacterial activity on the surface of plastics and other non-porous materials".

[0045] The results are shown in Table 3.

[0046] Table 3 Escherichia coli antibacterial rate Staphylococcus aureus antibacterial rate Example 1 99.74% 99.79% Example 2 99.86% 99.85% Example 3 99.79% 99.81% Comparative Example 1 72.55% 71.93% Comparative Example 2 72.36% 72.31% Comparative Example 3 99.76% 99.77% Comparative Example 4 99.81% 99.78% Comparative Example 5 99.79% 99.76% From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 3, it can be found that the fire-retardant PC / ABS material prepared in the present invention has good antibacterial properties.

[0047] By comparison, the antibacterial properties of Examples 1 to 3 are greater than those of Comparative Examples 1 to 2, indicating that pre-modified boron nitride is prepared by reacting hydroxylated boron nitride with N,N-diethyl-3-aminopropyltrimethoxysilane, and a tertiary amine group is introduced into the boron nitride, which undergoes a quaternization reaction with the chlorine on 2-chloroethanethiol. The resulting quaternary ammonium salt has good antibacterial properties, thereby improving the antibacterial properties of the fire-retardant PC / ABS material.

[0048] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fire-retardant PC / ABS material, characterized in that: The fire-retardant PC / ABS material is prepared by melt-blending modified PC, modified ABS and modified boron nitride; The modified PC is prepared by reacting 1H-imidazole-4,5-dimethanol with bisphenol A and diphenyl carbonate to obtain pre-modified PC, which is then reacted with 1-(chloro-methylphosphinoyl)ethylene; The modified ABS is prepared by reacting ABS with maleic anhydride to obtain pre-modified ABS, which is then reacted with 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine; The modified boron nitride is prepared by sequentially reacting hydroxylated boron nitride with N,N-diethyl-3-aminopropyltrimethoxysilane and 2-chloroethanethiol.

2. A method for preparing a fire-retardant PC / ABS material, characterized in that: The method comprises the following preparation steps: (1) Pre-modified boron nitride, 2-chloroethanethiol, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1: (0.4-0.5): (10-15), stirred at 65-75°C for 8-10 hours, and then vacuum distilled, washed, and dried to obtain modified boron nitride; (2) Pre-modified PC, 1-(chloro-methylphosphoryl)ethylene, sodium hydride, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1: (0.1-0.2): (0.05-0.07): (15-20), stirred at 50-60°C for 20-40 minutes, heated to 75-85°C, stirred for 2-3 hours, and added with saturated ammonium chloride solution 5-10 times the mass of pre-modified PC at 0-4°C. N,N-dimethylformamide was removed by rotary evaporation, washed, and dried to obtain modified PC. (3) Pre-modified ABS, 2-o-hydroxyphenyl-4-amino-6-methoxy-1,3,5-triazine, and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1: (0.06-0.07): (15-20), stirred at 40-50 ° C for 10-12 h, and then distilled under reduced pressure, washed, and dried to obtain modified ABS; (4) Modified PC, modified ABS, modified boron nitride, and azobisisobutyronitrile were mixed uniformly in a mass ratio of 1: (0.4~0.45): (0.02~0.04): (0.001~0.002), added to a Haake torque rheometer, melt blended at 200~220℃, 50~60r / min for 8~10min, placed in a flat vulcanizer, preheated at 230℃ for 5min, then hot pressed at a pressure of 20MPa for 5min, and then cold pressed at 15MPa for 3min, demolded, and a fire-retardant PC / ABS material was obtained.

3. The method for preparing a fire-retardant PC / ABS material according to claim 2, characterized in that: The preparation steps of the pre-modified boron nitride in step (1) are as follows: N, N-diethyl-3-aminopropyltrimethoxysilane and 98wt% ethanol aqueous solution are uniformly mixed in a mass ratio of 1: (50~100), ultrasonically dispersed for 20~30min to obtain N, N-diethyl-3-aminopropyltrimethoxysilane hydrolyzate, and hydroxylated boron nitride with a mass of 15~20 times that of N, N-diethyl-3-aminopropyltrimethoxysilane is added, stirred and reacted at 75~85°C for 6~8h, centrifuged, washed, and dried to obtain pre-modified boron nitride.

4. The method for preparing a fire-retardant PC / ABS material according to claim 2, characterized in that: The preparation steps of the pre-modified PC in step (2) are as follows: under a nitrogen atmosphere, 1H-imidazole-4,5-dimethanol, bisphenol A, diphenyl carbonate, and sodium hydroxide are uniformly mixed in a mass ratio of 1: (1.75~1.8): (3.4~3.6): (0.00001~0.00002), stirred and reacted at 220~240°C and a vacuum degree of 6~10kPa for 1.5~2.5h, heated to 240~250°C and 50~150Pa, stirred and reacted for 20~40min, cooled to room temperature, washed, and dried to obtain the pre-modified PC.

5. The method for preparing a fire-retardant PC / ABS material according to claim 2, characterized in that: The preparation steps of the pre-modified ABS in step (3) are as follows: under a nitrogen atmosphere, ABS, maleic anhydride, diisopropylbenzene peroxide, and butyl acetate are uniformly mixed in a mass ratio of 1: (0.1-0.2): (0.022-0.024): (5-10), stirred and reacted at 100-120° C. for 6-8 hours, cooled to room temperature, added with anhydrous ethanol in an amount of 15-20 times the mass of ABS, continued stirring for 20-40 minutes, filtered, washed, and dried to obtain pre-modified ABS.

6. The method for preparing a fire-retardant PC / ABS material according to claim 3, characterized in that: The preparation steps of the hydroxylated boron nitride are: mixing boron nitride and a 75wt% glucose aqueous solution in a mass ratio of 1:(10-12), ultrasonically dispersing for 20-30 minutes, adding the mixture into a planetary ball mill and ball milling for 10-12 hours, washing, and drying to obtain the hydroxylated boron nitride.

7. The method for preparing a fire-retardant PC / ABS material according to claim 5, characterized in that: The ABS is a general-grade ABS resin.

8. The method for preparing a fire-retardant PC / ABS material according to claim 6, characterized in that: The boron nitride is hexagonal boron nitride with a particle size of 80 nm.