Flame-retardant modified ABS plastic and preparation method thereof

Abstract

The invention belongs to the technical field of functional plastics, and particularly relates to a flame-retardant modified ABS (Acrylonitrile Butadiene Styrene) plastic and a preparation method thereof. The flame-retardant modified ABS plastic is prepared from the following components in parts by weight: 70 to 90 parts of ABS resin, 6 to 10 parts of a flame retardant, 0.5 to 1.5 parts of an ultraviolet light absorber, 0.2 to 1 part of a lubricant, 1 to 1.5 parts of a reinforcing agent and 0.5 to 1.5 parts of calcium carbonate, the structural formula of the flame retardant is # imgabs0; and the ABS plastic has excellent mechanical property and anti-aging property.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional plastics, and particularly relates to a flame-retardant modified ABS plastic and a preparation method thereof. Background Art

[0002] Acrylonitrile-butadiene-styrene copolymer (ABS) plastic is a thermoplastic material with excellent comprehensive properties, having high strength, high toughness and good rigidity. At the same time, ABS plastic has excellent processing performance, is suitable for various molding processes, has high surface gloss, and is easy to color and decorate. In addition, ABS plastic also has good chemical resistance, dimensional stability and electrical insulation, and has a certain recyclability.

[0003] However, ABS plastic also has some limitations: for example, the weather resistance of ABS plastic is poor and it is easy to age due to ultraviolet rays and weather conditions; the heat resistance of ABS plastic is limited and the heat distortion temperature is relatively low; and although the surface hardness of ABS plastic is high, it is easy to be scratched; ABS plastic is also sensitive to organic solvents such as esters and ketones, and produces black smoke and special odors when burning, so a flame retardant needs to be added. In addition, the cost of ABS plastic is relatively high, which may limit its use in some application fields with strict cost requirements.

[0004] Therefore, it is an urgent technical problem for those skilled in the art to develop a flame-retardant modified ABS plastic with weather resistance, mechanical properties and good compatibility. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, one of the purposes of the present invention is to provide a flame-retardant modified ABS plastic, which has excellent mechanical properties and anti-aging properties.

[0006] One of the purposes of the present invention is achieved by adopting the following technical solution:

[0007] A flame-retardant modified ABS plastic, in parts by weight, comprises the following components: 70-90 parts of ABS resin, 6-10 parts of flame retardant, 0.5-1.5 parts of ultraviolet absorber, 0.2-1 part of lubricant, 1-1.5 parts of reinforcing agent, 0.5-1.5 parts of calcium carbonate; the structural formula of the flame retardant is:

[0008]

[0009] Preferably, the preparation method of the flame retardant comprises the following steps:

[0010]

[0011] (1) DL-phenylglycinol and 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde are added to methanol for reaction. Sodium cyanoborohydride is added at room temperature and stirred for reaction. After purification, intermediate 1 is obtained;

[0012] (2) The intermediate 1 obtained in step (1) is added to acetone. After cooling, phosphorus oxychloride is added. The reaction is carried out for 40 - 60 min first, then the temperature is raised to room temperature and the reaction is continued for 2 - 4 h. Then, a methanol solution of sodium methoxide is added for heating reaction. After purification, the flame retardant is obtained.

[0013] Preferably, in step (1), the molar ratio of DL-phenylglycinol, 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde, and sodium cyanoborohydride is (10 - 12) mmol: 10 mmol: (10 - 12) mmol; the temperature of the reaction is 50 - 70 °C, the reaction time is 2.5 - 4.5 h; the temperature of the stirring reaction is 50 - 70 °C, and the stirring reaction time is 5 - 7 h.

[0014] Preferably, in step (2), the molar ratio of intermediate 1, phosphorus oxychloride, and sodium methoxide is 10 mmol: (8 - 10) mmol: (8 - 10) mmol.

[0015] Preferably, in step (2), the temperature after cooling is 3 - 8 °C; the temperature is controlled at 8 - 10 °C during the addition of phosphorus oxychloride; the temperature of the heating reaction is 60 - 70 °C, and the heating reaction time is 1 - 2 h.

[0016] Preferably, the preparation method of the enhancer is as follows:

[0017] Ascorbic acid and hexamethyldisilazane are added to acetonitrile for stirring reaction. After purification, the enhancer is obtained.

[0018] Preferably, the mass ratio of ascorbic acid to hexamethyldisilazane is 1: (2 - 3); the temperature of the stirring reaction is 60 - 70 °C, and the stirring reaction time is 3 - 5 h.

[0019] Preferably, the ultraviolet absorber is ultraviolet absorber UV-531 or ultraviolet absorber UVP-327, and the lubricant is stearic acid or ethylene bisstearamide.

[0020] The second object of the present invention is to provide a preparation method of flame retardant modified ABS plastic, and the preparation steps are simple.

[0021] The second object of the present invention is achieved by adopting the following technical solution:

[0022] The preparation method of the above-mentioned flame retardant modified ABS plastic includes the following steps:

[0023] Mix the raw materials evenly according to the weight ratio to obtain a blend; then, extrude and pelletize the blend and perform injection molding.

[0024] Preferably, during the extrusion and pelletizing process, the rotational speed of the twin-screw extruder screw is set to 150 - 250 rpm, and the temperatures of zones 1 - 5 are 180 °C, 185 °C, 195 °C, 190 °C, and 200 °C respectively; during the injection molding process, the temperature is set to 190 - 200 °C.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] In the flame-retardant modified ABS plastic of the present invention, flame retardants, reinforcing agents and other components are added. Among them, the flame retardant uses 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde as the starting material, and undergoes reductive amination of the aldehyde group with DL-phenylglycinol to obtain intermediate 1; intermediate 1 undergoes phosphorylation reaction with phosphoric acid and sodium methoxide. The phosphate ester in the above-mentioned flame retardant decomposes at high temperature to generate oxygen-containing substances such as phosphoric acid. These substances can promote the formation of a carbonized layer on the surface of ABS, isolate oxygen, and thus inhibit combustion. The oxygen-containing substances generated by the decomposition of the phosphate ester can also reduce the generation of smoke during the combustion process; the maleamide group in the flame retardant improves the anti-aging performance of the ABS plastic, and the flame retardant contains a fatty chain with three methylene groups, which can increase the flexibility of the material. In addition, the benzene ring structure contained in the flame retardant can also improve the compatibility between the functional filler and the ABS resin. In summary, the flame retardant of the present invention can improve the anti-aging property and flame retardancy while enhancing the mechanical properties of the material. The reinforcing agent contains hydroxyl groups and silicon-carbon bonds, which can tightly connect the ABS plastic with other functional fillers and improve the mechanical properties of the material by improving the interfacial compatibility between the materials. Specific Embodiments

[0027] The following further describes the present invention in combination with specific embodiments. It should be noted that, on the premise of no conflict, any combination of the following-described embodiments or technical features can form a new embodiment. 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 are all conventional products obtained through commercial channels without special instructions.

[0028] Example 1

[0029] Example 1 provides a flame-retardant modified ABS plastic. By weight, the flame-retardant modified ABS plastic consists of the following components: 80 parts of ABS resin, 7 parts of flame retardant, 1 part of ultraviolet absorber UV-531, 0.5 part of stearic acid, 1.2 parts of reinforcing agent, and 1 part of calcium carbonate.

[0030] The structural formula of the flame retardant is:

[0031]

[0032] The preparation method of the above flame retardant comprises the following steps:

[0033]

[0034] (1) According to the molar ratio of DL-phenylglycinol (CAS: 7568-92-5), 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde, and sodium cyanoborohydride of 11 mmol: 10 mmol: 11 mmol, DL-phenylglycinol and 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde are added to 20 mL of methanol in sequence, and the reaction is carried out at 60 °C for 3 h; after the reaction solution is cooled to room temperature, sodium cyanoborohydride (CAS: 25895-60-7) is added in batches. First, it is stirred at room temperature for 20 min, then the temperature is raised to 60 °C and stirred for reaction for 6 h. After the reaction is completed, water is added for quenching, and it is extracted three times with dichloromethane. The organic phases are combined and dried with magnesium sulfate. After concentration under reduced pressure, it is purified by reverse-phase preparative high-performance liquid chromatography (isocratic elution: 75% acetonitrile, 25% water) to obtain Intermediate 1, and the yield of Intermediate 1 is 68.32%.

[0035] The NMR result of Intermediate 1 is as follows:

[0036] 1 HNMR(C 15 H 18 N 2 O 3 , 400 MHz, d6-DMSO) 7.86 (s, 2H), 7.36 - 7.27 (m, 5H), 4.16 (s, 1H), 4.00 (t, 2H), 3.91 (t, 1H), 3.60 - 3.57 (m, 2H), 3.34 - 3.32 (m, 1H), 2.53 (t, 2H), 1.68 - 1.66 (m, 2H); MS(ESI) m / z = 274.14 [M]. The above results confirm that the obtained product is the target product.

[0037] (2) According to the molar ratio of Intermediate 1, phosphorus oxychloride, and sodium methoxide of 10 mmol: 9 mmol: 9 mmol, Intermediate 1 from step (1) is added to 30 mL of acetone. After cooling to 5 °C, phosphorus oxychloride is added, and the reaction is carried out for 50 min under the condition of controlling the temperature not exceeding 9 °C, and then the temperature is raised to room temperature and the reaction continues for 3 h; then a methanol solution of 30 wt% sodium methoxide is added to the reaction system, and the reaction is carried out at 65 °C for 1.5 h; after the reaction solution is concentrated, the by-products are dissolved in water, and the mixture is extracted with ethyl acetate. After separating, collecting, and drying the organic phase, ethyl acetate is removed by concentration, and then the remaining part is distilled to obtain the flame retardant, and the yield of the flame retardant is 24.17%.

[0038] The NMR results of the flame retardant are as follows:

[0039] 1 HNMR(C 17 H 23 N 2 O 6 P, 400 MHz, d6-DMSO) 7.86 (s, 2H), 7.36 - 7.27 (m, 5H), 4.57 - 4.32 (m, 2H), 4.16 (s, 1H), 4.00 (t, 2H), 3.91 (t, 1H), 3.78 (d, 6H), 2.53 (t, 2H), 1.68 - 1.66 (m, 2H); MS(ESI) m / z = 382.13 [M]. The above results confirm that the obtained product is the target product.

[0040] The preparation method of the above-mentioned reinforcing agent is as follows:

[0041] Ascorbic acid and hexamethyldisilazane were added to acetonitrile according to the mass ratio of 1:2.5, and stirred at 65 °C for 4 h. After removing the solvent, the reinforcing agent was obtained.

[0042] Example 1 also provides a preparation method of the above-mentioned flame-retardant modified ABS plastic. The specific preparation process is as follows:

[0043] According to the weight ratio, the raw materials were mixed evenly to obtain a blend; the blend was added to a twin-screw extruder, and the rotation speed of the screws of the twin-screw extruder was set at 200 rpm. The temperatures of zones 1 - 5 were 180 °C, 185 °C, 195 °C, 190 °C, and 200 °C respectively for extrusion granulation, and then injection molding was carried out through an injection molding machine at 195 °C.

[0044] Example 2

[0045] Example 2 provides a flame-retardant modified ABS plastic. By weight, the flame-retardant modified ABS plastic consists of the following components: 90 parts of ABS resin, 10 parts of flame retardant, 1.5 parts of ultraviolet absorber UVP-327, 1 part of ethylene bisstearamide, 1.5 parts of reinforcing agent, and 1.5 parts of calcium carbonate.

[0046] The structural formula of the flame retardant is the same as that in Example 1.

[0047] The preparation method of the above-mentioned flame retardant includes the following steps:

[0048] (1) According to the molar ratio of DL-phenylglycinol, 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde, and sodium cyanoborohydride of 1) mmol: 10 mmol: 12 mmol, DL-phenylglycinol and 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde were successively added to methanol, and the reaction was carried out at 70 °C for 2.5 h; after the reaction solution was cooled to room temperature, sodium cyanoborohydride was added in batches. First, it was stirred at room temperature for 20 min, then heated to 70 °C and stirred for 5 h. After the reaction was completed, water was added to quench the reaction. It was extracted three times with dichloromethane, the organic phases were combined, dried with magnesium sulfate, concentrated under reduced pressure, and then purified by reverse-phase preparative high-performance liquid chromatography (isocratic elution: 75% acetonitrile, 25% water) to obtain Intermediate 1. The yield of Intermediate 1 was 63.15%, and the 1 1H-NMR and MS(ESI) m / z were consistent with those in Example 1.

[0049] (2) According to the molar ratio of Intermediate 1, phosphorus oxychloride, and sodium methoxide of 10 mmol: 10 mmol: 10 mmol, Intermediate 1 from step (1) was added to 30 mL of acetone. After cooling to 8 °C, phosphorus oxychloride was added, and the reaction was carried out for 60 min under the condition of controlling the temperature not exceeding 10 °C, then the temperature was raised to room temperature and the reaction continued for 4 h; then a methanol solution of 30 wt% sodium methoxide was added to the reaction system, and the reaction was carried out at 70 °C for 1 h; after the reaction solution was concentrated, the by-products were dissolved in water, and the mixture was extracted with ethyl acetate. The organic phase was separated, collected, dried, and then concentrated to remove ethyl acetate. Then the residue was distilled to obtain the flame retardant. The yield of the flame retardant was 18.94%, and the 1 1H-NMR and MS(ESI) m / z were consistent with those in Example 1.

[0050] The preparation method of the above-mentioned enhancer is as follows:

[0051] According to the mass ratio of ascorbic acid and hexamethyldisilazane of 1:3, ascorbic acid and hexamethyldisilazane were added to acetonitrile, and the reaction was stirred at 70 °C for 3 h. After removing the solvent, the enhancer was obtained.

[0052] Example 2 also provides the preparation method of the above-mentioned flame retardant modified ABS plastic, and the specific preparation process is as follows:

[0053] According to the weight ratio, the raw materials were mixed evenly to obtain a blend; the blend was added to a twin-screw extruder, and the rotation speed of the twin-screw extruder screw was set at 250 rpm. The temperatures of zones 1-5 were 180 °C, 185 °C, 195 °C, 190 °C, and 200 °C respectively for extrusion granulation, and then injection molding was carried out through an injection molding machine at 200 °C.

[0054] Example 3

[0055] Example 3 provides a flame-retardant modified ABS plastic. Calculated by weight parts, the flame-retardant modified ABS plastic is composed of the following components: 70 parts of ABS resin, 6-10 parts of flame retardant, 0.5 part of ultraviolet absorber UV-531, 0.2 part of stearic acid, 1 part of reinforcing agent, and 0.5 part of calcium carbonate.

[0056] The structural formula of the flame retardant is the same as that in Example 1.

[0057] The preparation method of the above flame retardant includes the following steps:

[0058] (1) According to the molar ratio of DL-phenylglycinol, 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde, and sodium cyanoborohydride of 10 mmol: 10 mmol: 10 mmol, add DL-phenylglycinol and 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde to 20 mL of methanol in sequence, and react at 50 °C for 4.5 h; after the reaction solution is cooled to room temperature, add sodium cyanoborohydride in batches. First, stir at room temperature for 20 min, then raise the temperature to 50 °C and stir for 7 h. After the reaction is completed, quench with water, extract three times with dichloromethane, combine the organic phases, dry with magnesium sulfate, concentrate under reduced pressure, and then purify by reversed-phase preparative high-performance liquid chromatography (isocratic elution: 75% acetonitrile, 25% water) to obtain Intermediate 1. The yield of Intermediate 1 is 60.55%. The 1 1H-NMR and MS (ESI) m / z of Intermediate 1 are consistent with those in Example 1.

[0059] (2) According to the molar ratio of Intermediate 1, phosphorus oxychloride, and sodium methoxide of 10 mmol: 8 mmol: 8 mmol, add Intermediate 1 from step (1) to acetone. After cooling to 3 °C, add phosphorus oxychloride (, control the temperature not exceeding 8 °C and react for 40 min, then raise the temperature to room temperature and continue to react for 2 h; then add a methanol solution of 30 wt% sodium methoxide to the reaction system, heat to 60 °C and react for 2 h; after the reaction solution is concentrated, dissolve the by-products with water, then extract the mixture with ethyl acetate, separate, collect and dry the organic phase, concentrate to remove ethyl acetate, and then distill the remaining part to obtain the flame retardant. The yield of the flame retardant is 17.23%. The 1 1H-NMR and MS (ESI) m / z of the flame retardant are consistent with those in Example 1.

[0060] The preparation method of the above reinforcing agent is as follows:

[0061] According to the mass ratio of ascorbic acid to hexamethyldisilazane of 1:2, add ascorbic acid and hexamethyldisilazane to acetonitrile, stir and react at 60 °C for 5 h, and obtain the reinforcing agent after removing the solvent.

[0062] Example 3 also provides a preparation method of the above flame-retardant modified ABS plastic. The specific preparation process is as follows:

[0063] Mix each raw material evenly according to the weight part ratio to obtain a blend; add the blend to a twin-screw extruder, set the rotation speed of the twin-screw extruder screw to 150 rpm, and the temperatures of zones 1-5 are 180 °C, 185 °C, 195 °C, 190 °C, and 200 °C respectively for extrusion granulation, and then injection mold through an injection molding machine at 190 °C, and that's it.

[0064] Comparative Example 1

[0065] Comparative Example 1 provides an ABS plastic. By weight, the ABS plastic consists of the following components: 80 parts of ABS resin, 7 parts of flame retardant, 1 part of ultraviolet absorber UV-531, 0.5 part of stearic acid, 1.2 parts of reinforcing agent, and 1 part of calcium carbonate.

[0066] The preparation method of the above flame retardant is as follows:

[0067] According to the molar ratio of DL-phenylglycinol, phosphorus oxychloride, and methanol solution of sodium methoxide of 10 mmol: 9 mmol: 9 mmol, add DL-phenylglycinol to acetone, mix evenly and cool to 5 °C, add phosphorus oxychloride under stirring, control the temperature at 9 °C, react for 50 min and then gradually warm up to room temperature, react for 3 h, then add 30 wt% methanol solution of sodium methoxide (9 mmol), and heat and react at 65 °C for 1.5 h; after the reaction solution is concentrated, dissolve the by-products with water, then extract the mixture with ethyl acetate, separate, collect and dry the organic phase, concentrate to remove ethyl acetate, and then distill the remaining part to obtain the flame retardant.

[0068] The preparation method of the reinforcing agent is the same as that in Example 1.

[0069] Comparative Example 1 also provides the preparation method of the above ABS plastic, which is the same as that in Example 1 specifically.

[0070] Comparative Example 2

[0071] Comparative Example 2 provides an ABS plastic. By weight, the ABS plastic consists of the following components: 80 parts of ABS resin, 7 parts of flame retardant, 1 part of ultraviolet absorber UV-531, 0.5 part of stearic acid, 1.2 parts of hexamethyldisilazane, and 1 part of calcium carbonate.

[0072] The structural formula and preparation method of the above flame retardant are the same as those in Example 1.

[0073] Comparative Example 2 also provides the preparation method of the above ABS plastic, which is the same as that in Example 1 specifically.

[0074] Test Example

[0075] The properties of the ABS plastics prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention are described below.

[0076] Oxygen index: Tested according to the standard of GB / T 2406-2008;

[0077] Impact strength: Tested according to the standard of GB / T 1043.1-2018;

[0078] Tensile strength: Tested according to the standard of GB / T 1040.1-2018, and the test speed is 50 mm / min;

[0079] Yellowing index: According to the test method of plastic laboratory light source exposure test in GB / T 16422.2-2022, place it in a xenon lamp exposure light aging test chamber for irradiation, and then measure its yellowing index according to the test method of plastic yellowing index in GB 2409-80. The test time is 1000 h; The results are shown in Table 1.

[0080] Table 1

[0081] Grouping Tensile strength (MPa) <![CDATA[Impact strength (kJ / m 2 )]]> Oxygen index (%) Yellowness index Example 1 63.4 20.0 35.8 0.15 Example 2 62.7 19.4 35.5 0.16 Example 3 62.3 18.6 35.1 0.16 Comparative example 1 59.5 16.2 34.6 0.53 Comparative example 2 54.1 12.7 35.3 0.21

[0082] As can be seen from the above, compared with the flame retardant of Comparative Example 1, the flame retardants prepared in Examples 1-3 of the present invention can improve the mechanical properties and light aging resistance of ABS plastics.

[0083] Further analysis shows that the present invention uses 3-(2,5-dioxo-2,5-dihydropyrrol-1-yl) propionaldehyde as the starting material, and reacts with DL-phenylglycinol by reductive amination of the aldehyde group to obtain Intermediate 1; Intermediate 1 reacts with phosphoric acid and sodium methoxide to carry out phosphoesterification and other reactions to obtain the flame retardant. The phosphate ester in the flame retardant of the present invention decomposes at high temperature to generate oxygen-containing substances such as phosphoric acid. These substances can promote the formation of a carbonized layer on the surface of ABS to isolate oxygen, thereby inhibiting combustion. The oxygen-containing substances generated by the decomposition of the phosphate ester can also reduce the generation of flue gas during the combustion process; the maleamide group in the flame retardant improves the anti-aging performance of ABS plastics, and the flame retardant contains a fatty chain with three methylenes, which can increase the flexibility of the material. In addition, the benzene ring structure contained in the flame retardant can also improve the compatibility between the functional filler and the ABS resin. In summary, the flame retardant of the present invention can improve the anti-aging and flame retardant properties while also enhancing the mechanical properties of the material.

[0084] Compared with the ABS plastics prepared by using hexamethyldisilazane in Comparative Example 2, the ABS plastics prepared in Examples 1-3 of the present invention have excellent mechanical properties. Further analysis shows that the hydroxyl groups and silicon-carbon bonds contained in the enhancer of the present invention can tightly connect the ABS plastics with other functional fillers, and improve the mechanical properties of the material by improving the interfacial compatibility between the materials.

[0085] The above embodiments are only the preferred embodiments of the present invention, and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A flame retardant modified ABS plastic, characterized in that: The composition comprises the following components by weight: 70-90 parts of ABS resin, 6-10 parts of flame retardant, 0.5-1.5 parts of ultraviolet absorber, 0.2-1 parts of lubricant, 1-1.5 parts of reinforcing agent and 0.5-1.5 parts of calcium carbonate; the structural formula of the flame retardant is:

2. The flame retardant modified ABS plastic according to claim 1, characterized in that: The preparation method of the flame retardant comprises the following steps: (1) DL-phenylglycinol and 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal are added to methanol for reaction, sodium cyanoborohydride is added for stirring reaction at room temperature, and intermediate 1 is obtained after purification; (2) The intermediate 1 of step (1) is added to acetone, and phosphorus oxychloride is added after cooling, and the reaction is first performed for 40 to 60 minutes, and then the temperature is raised to room temperature and the reaction is continued for 2 to 4 hours, and then a methanol solution of sodium methoxide is added to heat the reaction, and a flame retardant is obtained after purification.

3. The flame retardant modified ABS plastic according to claim 2, characterized in that: The molar ratio of DL-phenylglycinol, 3-(2,5-dioxy-2,5-dihydropyrrol-1-yl)propanal and sodium cyanoborohydride in step (1) is (10-12) mmol:10 mmol:(10-12) mmol; the reaction temperature is 50-70° C., and the reaction time is 2.5-4.5 h; the stirring reaction temperature is 50-70° C., and the stirring reaction time is 5-7 h.

4. The flame retardant modified ABS plastic according to claim 2, characterized in that: The molar ratio of the intermediate 1, phosphorus oxychloride and sodium methoxide in step (2) is 10 mmol: (8-10) mmol: (8-10) mmol.

5. The flame retardant modified ABS plastic according to claim 2, characterized in that: The temperature after cooling in step (2) is 3-8°C; the temperature during the addition of phosphorus oxychloride is controlled at 8-10°C; the temperature of the heating reaction is 60-70°C, and the heating reaction time is 1-2h.

6. The flame retardant modified ABS plastic according to claim 1, characterized in that: The preparation method of the enhancer is as follows: Ascorbic acid and hexamethyldisilazane are added to acetonitrile for stirring reaction, and an enhancer is obtained after purification.

7. The flame retardant modified ABS plastic according to claim 6, characterized in that: The mass ratio of ascorbic acid to hexamethyldisilazane is 1:(2-3); the temperature of the stirring reaction is 60-70° C., and the time of the stirring reaction is 3-5 hours.

8. The flame retardant modified ABS plastic according to claim 1, characterized in that: The ultraviolet absorber is ultraviolet absorber UV-531 or ultraviolet absorber UVP-327, and the lubricant is stearic acid or ethylene bis stearic acid amide.

9. The method for preparing the flame retardant modified ABS plastic according to any one of claims 1 to 8, characterized in that: The following steps are involved: The raw materials are uniformly mixed according to the weight ratio to obtain a blend; the blend is extruded, granulated and injection molded.

10. The method for preparing the flame retardant modified ABS plastic according to claim 9, characterized in that: During the extrusion granulation process, the speed of the twin-screw extruder screw is set at 150-250rpm, and the temperatures of zones 1-5 are 180°C, 185°C, 195°C, 190°C, and 200°C respectively; during the injection molding process, the temperature is set at 190-200°C.

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