An impact-resistant acrylic sheet and its preparation method

Abstract

This invention discloses an impact-resistant acrylic sheet and its preparation method, belonging to the technical field of acrylic sheet. 80-100 parts of methyl methacrylate, 10-15 parts of flame retardant, 5-15 parts of EPDM rubber, and 2-8 parts of polypropylene wax are added to a stirring device and stirred evenly. Then, 15-30 parts of impact-resistant filler, 3-9 parts of lubricant, and 0.2-2 parts of initiator are added and mixed evenly. The mixture is then extruded into a mold using a screw extruder, cured at 60-80℃ for 2-3 hours, and then cured at 10-35℃ for 6-7 hours. After demolding, the impact-resistant acrylic sheet is obtained. The impact-resistant filler containing nano-silica and glass fiber, and the flame retardant containing halogen-free flame-retardant elements nitrogen, phosphorus, and silicon, can be highly dispersed and stably present in the acrylic sheet, thus maximizing their effectiveness and giving the acrylic sheet of this invention excellent and stable impact resistance and highly efficient and safe flame retardancy.

Description

Technical Field

[0001] This invention belongs to the field of acrylic sheet technology, specifically, it relates to an impact-resistant acrylic sheet and its preparation method. Background Technology

[0002] Acrylic, also known as PMMA or plexiglass, belongs to the polyacrylate family of materials. It is an important, well-developed, and malleable polymer material with good chemical stability, weather resistance, and light transmittance. It is easy to dye and process, and is often found in the form of granules, sheets, and pipes. It has applications in construction, household products, automobiles, and communications, such as security doors and windows, decorative ceilings, backlight diffusers for appliance displays, bathtubs, automotive lighting components, and fiber optic core materials.

[0003] Although there are many types of acrylic sheets on the market, they often suffer from poor impact resistance in practical applications. Current technology typically adds inorganic fillers during processing to improve impact resistance; however, the poor compatibility of these fillers with the matrix can affect the mechanical properties of the acrylic sheet itself. Furthermore, acrylic sheets are commonly used in interior partitions, furniture, and other architectural and decorative applications. These applications not only require the material to be aesthetically pleasing, durable, and impact-resistant, but also to possess a certain degree of fire resistance to minimize damage and harm in the event of a fire. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an impact-resistant acrylic sheet and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An impact-resistant acrylic sheet comprises the following raw materials in parts by weight: 80-100 parts methyl methacrylate, 15-30 parts impact-resistant filler, 10-15 parts flame retardant, 5-15 parts EPDM rubber, 3-9 parts lubricant, 2-8 parts polypropylene wax, and 0.2-2 parts initiator.

[0007] Furthermore, the impact-resistant filler is prepared by the following steps:

[0008] (1) Purge the dry three-necked flask with nitrogen for 30 min to remove air and moisture. Add bis[3-(triethoxysilyl)propyl]amine, tetraisopropyl titanate and benzene to the flask and stir to dissolve. Then slowly add 1,4-pentadien-3-ol. After the addition is complete, heat to 90℃ and react for 24 h. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain intermediate 1. The ratio of bis[3-(triethoxysilyl)propyl]amine, 1,4-pentadien-3-ol, tetraisopropyl titanate and benzene is 75 g: 14.6 mL: 0.5 mL: 250 mL.

[0009] By controlling the molar ratio of bis[3-(triethoxysilyl)propyl]amine to 1,4-pentadien-3-ol to be 1.1-1.2:1, the silanoxy group of bis[3-(triethoxysilyl)propyl]amine and the hydroxyl group of 1,4-pentadien-3-ol undergo the following chemical reaction under the catalysis of tetraisopropyl titanate, as shown in the following process:

[0010]

[0011] (2) Replace the air and moisture in the dry brown three-necked flask with nitrogen, then add intermediate 1, glycidyl methacrylate and benzene in sequence, stir thoroughly, heat to 75°C, keep the temperature for 8 hours, cool to room temperature after the reaction is completed, distill under reduced pressure, and purify by column chromatography (the eluent is a mixed solvent of benzene and acetone, with a volume ratio of benzene to acetone of 9:1), distill under reduced pressure to obtain intermediate 2; the ratio of intermediate 1, glycidyl methacrylate and benzene is 60g:14.5mL:250mL;

[0012] The molar ratio of intermediate 1 to glycidyl methacrylate was controlled at 1.1-1.2:1. Under heating conditions, the -NH- group of intermediate 1 and the epoxy group of glycidyl methacrylate underwent an addition reaction, as shown below:

[0013]

[0014] (3) Take dry nano-silica and glass fiber and disperse them in a mixed solution of anhydrous ethanol and water. Add acetic acid to adjust the pH to 4, stir for 30 min, and transfer to a three-necked flask. Disperse intermediate 2 in benzene, stir for 15 min, and then transfer to the above three-necked flask. After the transfer is complete, heat to 65℃ and react for 1 h. After the reaction is complete, cool to room temperature, centrifuge, take the precipitate and sonicate it in anhydrous ethanol for 10 min, and dry it at 80℃ for 12 h to obtain the impact-resistant filler. The mass ratio of nano-silica, glass fiber and intermediate 2 is 5:15:1.

[0015] After hydrolysis, the silanol groups generated by intermediate 2 react with the hydroxyl groups on the surface of nano-silica and glass fibers to form stable chemical bonds. The formation of these new chemical bonds reduces the surface energy of the nano-silica and glass fibers, stabilizing them. Simultaneously, the organic medium on the particle surface increases the spatial resistance to particle aggregation, thus improving the dispersibility of the nano-silica and glass fibers, significantly increasing the dispersion of the impact-resistant filler in the acrylic sheet. Furthermore, the impact-resistant filler contains multiple carbon-carbon double bonds, allowing it to react chemically with methyl methacrylate, EPDM rubber, and flame retardants (all containing carbon-carbon double bonds) under the action of an initiator. This results in the highly dispersed and stable existence of the impact-resistant filler in the acrylic sheet, while also promoting the dispersibility of the flame retardant. Nano-silica, due to its tiny nano-particles, can form a uniform dispersion in the material, thereby enhancing the overall strength and toughness of the acrylic sheet and significantly improving its mechanical strength and wear resistance. Glass fiber, due to its high strength and rigidity, can effectively prevent the acrylic sheet from deforming or cracking under stress, significantly improving its tensile strength and impact resistance. Therefore, the impact-resistant filler containing nano-silica and glass fiber of this invention can effectively improve the impact resistance and wear resistance of acrylic sheets.

[0016] Furthermore, the flame retardant is prepared by the following steps:

[0017] S1. A three-necked flask was purged with nitrogen for 30 minutes to remove air and moisture. Then, hydroxyethyl methacrylate and chloroform were added and stirred until dissolved. Octadecyltrichlorosilane was then slowly added. After the addition was complete, the mixture was stirred and heated to 30°C. The reaction was maintained at this temperature for 6 hours. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure to obtain intermediate 3. The ratio of hydroxyethyl methacrylate, octadecyltrichlorosilane, and chloroform was 18.2 mL: 63.7 mL: 200 mL.

[0018] Under heating conditions, with the molar ratio of hydroxyethyl methacrylate to octadecyltrichlorosilane controlled at 1:1.05-1.1, hydroxyethyl methacrylate and octadecyltrichlorosilane undergo an esterification reaction, as shown below:

[0019]

[0020] S2. Dry the three-necked flask with nitrogen for 30 minutes to remove air and moisture. Then add 3-buten-1-ol and chloroform, stir to dissolve, and then slowly add intermediate 3. After the addition is complete, stir and heat to 30°C, and maintain the temperature for 7 hours. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain intermediate 4. The ratio of intermediate 3, 3-buten-1-ol and chloroform is 62.4 g: 10.3 mL: 250 mL.

[0021] Under heating conditions, with the molar ratio of intermediate 3 to 3-buten-1-ol controlled at 1.05-1.1:1, intermediate 3 and 3-buten-1-ol undergo an esterification reaction, as shown below:

[0022]

[0023] S3. Dry the three-necked flask with nitrogen for 30 minutes to remove air and moisture. Then add 3-[(hydroxymethyl)amino]-3-oxopropylphosphonic acid-dimethyl ester and dimethyl sulfoxide, stir to dissolve, and then slowly add intermediate 4. After the addition is complete, stir and heat to 40°C, and maintain the temperature for 8 hours. After the reaction is completed, cool to room temperature and distill under reduced pressure to obtain the flame retardant. The ratio of intermediate 4, 3-[(hydroxymethyl)amino]-3-oxopropylphosphonic acid-dimethyl ester and dimethyl sulfoxide is 26 g: 11.6 g: 220 mL.

[0024] Under heating conditions, the molar ratio of intermediate 4 to 3-[(hydroxymethyl)amino]-3-oxopropylphosphonic acid-dimethyl ester is controlled at 1:1.05-1.1. Intermediate 4 and 3-[(hydroxymethyl)amino]-3-oxopropylphosphonic acid-dimethyl ester undergo an esterification reaction, as shown below:

[0025]

[0026] This invention relates to a flame retardant containing phosphate ester groups and halogen-free flame retardant elements nitrogen and silicon. The phosphate ester groups undergo hydrolysis at high temperatures, producing phosphoric acid and methanol. Phosphoric acid can react with free radicals generated during combustion to form a phosphorus oxide layer, preventing contact between oxygen and fuel, thus achieving a flame-retardant effect. Furthermore, phosphate ester compounds can decompose at high temperatures, absorbing heat, slowing the combustion rate of the material, prolonging the combustion time, and improving the flame-retardant performance of the material. This thermal stabilization effect helps to slow the spread of flames and enhance the flame-retardant effect. The nitrogen-containing flame retardant releases non-flammable gases such as ammonia, nitrogen, deep nitrogen oxides, and water vapor upon thermal decomposition. The generation of these gases and the heat absorption during the decomposition of the flame retardant remove most of the heat, significantly reducing the surface temperature of the polymer. In addition, these non-flammable gases can dilute the concentration of oxygen in the air and the flammable gases produced by the thermal decomposition of the polymer. Simultaneously, they react with oxygen in the air to generate nitrogen, water, and deep oxides, consuming oxygen on the material surface, thereby achieving a good flame-retardant effect. During combustion, silicon-containing flame retardants can form a polymer gradient material with an organosilicon flame retardant enrichment layer on the surface. Once burned, this generates an inorganic oxygen-barrier and heat-insulating protective layer unique to polysiloxanes, containing Si or Si-C bonds. This prevents the escape of combustion decomposition products and inhibits the thermal decomposition of polymer materials, achieving flame retardancy, low smoke, and low toxicity. Furthermore, silicon-containing flame retardants generate non-combustible gases such as H2O and CO2 during combustion, diluting the oxygen concentration to achieve a synergistic flame-retardant effect. Nitrogen, phosphorus, and silicon elements work together through chemical reactions, physical isolation, and gas-phase solidification to effectively improve the flame retardant properties of the flame retardant, protecting the acrylic sheet and making it less flammable.

[0027] Flame retardants contain long carbon chains, which can increase the toughness and impact resistance of acrylic sheets.

[0028] Flame retardants contain multiple carbon-carbon double bonds, which allows them to react chemically with methyl methacrylate, impact fillers, and EPDM rubber under the action of an initiator. This results in cross-linking of the flame retardant, methyl methacrylate, impact fillers, and EPDM rubber, forming a stable and robust hybrid network structure. The flame retardant can be uniformly dispersed and stably exist in the acrylic sheet, fully exerting its mechanical properties such as flame retardancy, enhanced toughness, and impact resistance.

[0029] Furthermore, the lubricant is one or more of zinc stearate, magnesium stearate, and calcium stearate.

[0030] Furthermore, the initiator is one or more of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, dimethyl azobisisobutyrate, and azobiscyclohexylformitrile.

[0031] A method for preparing an impact-resistant acrylic sheet includes the following steps:

[0032] Methyl methacrylate, flame retardant, EPDM rubber, and polypropylene wax are added to a mixing device and stirred evenly. Then, impact-resistant filler, lubricant, and initiator are added and mixed evenly. The mixture is then extruded into a mold through a screw extruder and cured at 60-80℃ for 2-3 hours and at 10-35℃ for 6-7 hours. After demolding, impact-resistant acrylic sheet is obtained.

[0033] The beneficial effects of the present invention are that the impact-resistant filler containing nano-silica and glass fiber and the flame retardant containing halogen-free flame retardant elements nitrogen, phosphorus and silicon can be highly dispersed and stably present in the acrylic sheet, so that both can play their maximum role, thereby giving the acrylic sheet of the present invention excellent and stable impact resistance and efficient and safe flame retardancy. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1: Preparation of impact-resistant filler, the specific steps are as follows:

[0036] (1) Purge a 500 mL dry three-necked flask with nitrogen for 30 min to remove air and moisture. Add 75 g of bis[3-(triethoxysilyl)propyl]amine, 0.5 mL of tetraisopropyl titanate and 250 mL of benzene to the flask and stir to dissolve. Then slowly add 14.6 mL of 1,4-pentadien-3-ol. After the addition is complete, heat to 90 °C and react for 24 h. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain intermediate 1.

[0037] (2) Replace the air and moisture in a 500 mL dry brown three-necked flask with nitrogen, then add 60 g of intermediate 1, 14.5 mL of glycidyl methacrylate and 250 mL of benzene in sequence. After stirring thoroughly, heat to 75 °C and keep the temperature for 8 h. After the reaction is completed, cool to room temperature, distill under reduced pressure, and purify by column chromatography (the eluent is a mixed solvent of benzene and acetone, with a volume ratio of benzene to acetone of 9:1). Distill under reduced pressure to obtain intermediate 2.

[0038] (3) Take 15g of dry nano silica and 45g of glass fiber and disperse them in a mixed solution of 150mL of anhydrous ethanol and 100mL of water. Add acetic acid to adjust the pH to 4, stir for 30min, and transfer to a 500mL three-necked flask. Disperse 3g of intermediate 2 in 20mL of benzene, stir for 15min, and then transfer to the above three-necked flask. After the transfer is complete, heat to 65℃ and react for 1h. After the reaction is completed, cool to room temperature, centrifuge, take the precipitate and sonicate it in anhydrous ethanol for 10min, and dry it at 80℃ for 12h to obtain the impact-resistant filler.

[0039] Example 2: Preparation of flame retardant, the specific steps are as follows:

[0040] S1. Purge a 500 mL dry three-necked flask with nitrogen for 30 min to remove air and moisture. Then add 18.2 mL of hydroxyethyl methacrylate and 200 mL of chloroform. Stir to dissolve, then slowly add 63.7 mL of octadecyltrichlorosilane. After the addition is complete, stir and heat to 30 °C. Maintain the temperature for 6 h. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain intermediate 3.

[0041] S2. Purge a 500 mL dry three-necked flask with nitrogen for 30 min to remove air and moisture. Then add 10.3 mL of 3-buten-1-ol and 250 mL of chloroform. Stir to dissolve, then slowly add 62.4 g of intermediate 3. After the addition is complete, stir and heat to 30 °C. Maintain the temperature for 7 h. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain intermediate 4.

[0042] S3. Purge a 500 mL dry three-necked flask with nitrogen for 30 min to remove air and moisture. Then add 11.6 g of 3-[(hydroxymethyl)amino]-3-oxopropylphosphonic acid-dimethyl ester and 220 mL of dimethyl sulfoxide. After stirring to dissolve, slowly add 26 g of intermediate 4. After the addition is complete, stir and heat to 40 °C. Maintain the temperature for 8 h. After the reaction is complete, cool to room temperature and distill under reduced pressure to obtain the flame retardant.

[0043] Example 3: Preparation of acrylic sheet, the specific steps are as follows:

[0044] 80 parts of methyl methacrylate, 10 parts of the flame retardant prepared in Example 2, 5 parts of EPDM rubber, and 2 parts of polypropylene wax were added to a mixing device and stirred evenly. Then, 15 parts of the impact-resistant filler prepared in Example 1, 3 parts of calcium stearate, and 0.2 parts of azodicyclohexylformonitrile were added and mixed evenly. The mixture was then extruded into a mold through a screw extruder, cured at 60°C for 3 hours, and then cured at 10°C for 6 hours. After demolding, an acrylic sheet was obtained.

[0045] Example 4: Preparation of acrylic sheet, the specific steps are as follows:

[0046] 90 parts of methyl methacrylate, 12 parts of the flame retardant prepared in Example 2, 13 parts of EPDM rubber, and 6 parts of polypropylene wax were added to a mixing device and stirred evenly. Then, 25 parts of the impact-resistant filler prepared in Example 1, 8 parts of magnesium stearate, and 1 part of dimethyl azobisisobutyrate were added and mixed evenly. The mixture was then extruded into a mold through a screw extruder, cured at 70°C for 2.5 hours, and cured at 25°C for 6.5 hours. After demolding, an acrylic sheet was obtained.

[0047] Example 5: Preparation of acrylic sheet, the specific steps are as follows:

[0048] 100 parts of methyl methacrylate, 15 parts of the flame retardant prepared in Example 2, 15 parts of EPDM rubber, and 8 parts of polypropylene wax were added to a mixing device and stirred evenly. Then, 30 parts of the impact-resistant filler prepared in Example 1, 9 parts of zinc stearate, 1 part of azobisisobutyronitrile, and 1 part of azobisisovalerate were added and mixed evenly. The mixture was then extruded into a mold through a screw extruder, cured at 80°C for 2 hours, and cured at 35°C for 7 hours. After demolding, an acrylic sheet was obtained.

[0049] Comparative Example 1: Preparation of acrylic sheet, the specific steps are as follows:

[0050] The remaining steps remain unchanged, except that the impact-resistant filler in Example 3 is replaced with 3.8 parts of nano-silica and 11.2 parts of glass fiber to prepare an acrylic sheet.

[0051] Comparative Example 2: Preparation of acrylic sheet, the specific steps are as follows:

[0052] The remaining steps remain the same, except that the flame retardant in Example 3 is replaced with melamine polyphosphate, thereby preparing an acrylic sheet.

[0053] Performance testing

[0054] Acrylic sheets prepared in Examples 3-5 and Comparative Examples 1-2 were selected and pressed into sheets with a thickness of 1 mm in a vulcanizing machine. After cold pressing, the sheets were cut into strips of 125 mm × 13 mm × 1.6 mm. After being placed in a constant temperature chamber at 23°C and 50% relative humidity for 48 hours, they were subjected to a UL94 combustion test.

[0055] Flame retardant ratings include:

[0056] HB: The lowest flame retardant rating in the UL94 standard. It requires a burning rate of less than 40 mm / min for samples 3 to 13 mm thick; less than 70 mm / min for samples less than 3 mm thick; or extinguishing before reaching the 100 mm mark.

[0057] V-2: After two 10-second burning tests on the sample, the flame extinguishes within 30 seconds. It can ignite cotton wool up to 30cm below.

[0058] V-1: After two 10-second burning tests on the sample, the flame extinguishes within 30 seconds. It cannot ignite cotton wool 30cm below.

[0059] V-0: After two 10-second burning tests on the sample, the flame extinguishes within 10 seconds.

[0060] The flame retardant test results are shown in Table 1 below:

[0061] Table 1

[0062] Test Project Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Flame retardant rating V-0 V-0 V-0 V-0 V-1

[0063] Acrylic sheets prepared in Examples 3-5 and Comparative Examples 1-2 were selected. The sample dimensions were 63.5mm × 12.7mm × 3.2mm, with a remaining notch width of 10.71mm. The samples were tested according to ASTM D-256 standard, and the results are shown in Table 2 below.

[0064] Table 2

[0065] Test Project Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 <![CDATA[Impact strength kg / cm 3 > 38.7 39.2 39.6 33.4 36.1

[0066] As can be seen from the test results in Tables 1 and 2, the acrylic sheets prepared in Examples 3-5 of the present invention have superior flame retardancy and impact resistance.

[0067] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0068] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. An impact-resistant acrylic sheet, characterized in that, The raw materials include the following parts by weight: 80-100 parts methyl methacrylate, 15-30 parts impact-resistant filler, 10-15 parts flame retardant, 5-15 parts EPDM rubber, 3-9 parts lubricant, 2-8 parts polypropylene wax, and 0.2-2 parts initiator. The impact-resistant filler is prepared through the following steps: (1) After purging the flask with nitrogen, add bis[3-(triethoxysilyl)propyl]amine, tetraisopropyl titanate and benzene, stir and then add 1,4-pentadien-3-ol. React at 90℃ for 24 h, cool and distill under reduced pressure to obtain intermediate 1; the ratio of bis[3-(triethoxysilyl)propyl]amine, 1,4-pentadien-3-ol, tetraisopropyl titanate and benzene is 75 g: 14.6 mL: 0.5 mL: 250 mL; (2) Replace the air and moisture in the flask with nitrogen, add intermediate 1, glycidyl methacrylate and benzene, stir, heat to 75℃ and react for 8 hours, cool, distill under reduced pressure, purify by column chromatography, distill under reduced pressure to obtain intermediate 2; the ratio of intermediate 1, glycidyl methacrylate and benzene is 60g:14.5mL:250mL. (3) Disperse nano-silica and glass fiber in anhydrous ethanol and water, add acetic acid to adjust pH=4, stir, and transfer to a flask; disperse intermediate 2 in benzene, stir, and transfer to the above flask; heat to 65℃ and react for 1h, cool, centrifuge, take the precipitate and sonicate in anhydrous ethanol for 10min, dry, and obtain the impact-resistant filler; the mass ratio of nano-silica, glass fiber and intermediate 2 is 5:15:1; The flame retardant is prepared by the following steps: S1. After purging the flask with nitrogen, add hydroxyethyl methacrylate and chloroform, stir, add octadecyltrichlorosilane, heat to 30℃ and react for 6 hours. After the reaction is completed, cool to room temperature and distill under reduced pressure to obtain intermediate 3. The ratio of hydroxyethyl methacrylate, octadecyltrichlorosilane and chloroform is 18.2mL:63.7mL:200mL. S2. After blowing nitrogen into the flask, add 3-buten-1-ol and chloroform, stir, add intermediate 3, heat to 30℃ and react for 7h, cool, and distill under reduced pressure to obtain intermediate 4; the ratio of intermediate 3, 3-buten-1-ol and chloroform is 62.4g:10.3mL:250mL. S3. After purging the flask with nitrogen, add 3-[(hydroxymethyl)amino]-3-oxopropylphosphonic acid-dimethyl ester and dimethyl sulfoxide, stir, add intermediate 4, heat to 40℃ and react for 8 hours, cool, and distill under reduced pressure to obtain the flame retardant; the ratio of intermediate 4, 3-[(hydroxymethyl)amino]-3-oxopropylphosphonic acid-dimethyl ester and dimethyl sulfoxide is 26g:11.6g:220mL.

2. The impact-resistant acrylic sheet according to claim 1, characterized in that, The lubricant is one or more of zinc stearate, magnesium stearate, and calcium stearate.

3. The impact-resistant acrylic sheet according to claim 1, characterized in that, The initiator is one or more of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, and azobisisobutyrate dimethyl ester and azobiscyclohexylformitrile.

4. The method for preparing an impact-resistant acrylic sheet according to claim 1, characterized in that, Includes the following steps: Methyl methacrylate, flame retardant, EPDM rubber, and polypropylene wax are added to a mixing device and stirred evenly. Then, impact-resistant filler, lubricant, and initiator are added and mixed evenly. The mixture is then extruded into a mold through a screw extruder and cured at 60-80℃ for 2-3 hours and at 10-35℃ for 6-7 hours. After demolding, impact-resistant acrylic sheet is obtained.

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