Heat-resistant polymethyl methacrylate composite material and preparation method thereof
By modifying montmorillonite and glass fiber treatment, combined with polycarbonate and compatibilizer, the heat resistance and processability problems of polymethyl methacrylate are solved, forming a composite material with good thermal stability, which is suitable for high-temperature processing.
Patent Information
- Application Number
- CN202510773801.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-11
- Publication Date
- 2025-09-09
AI Technical Summary
Polymethyl methacrylate has poor heat resistance, which causes it to decompose at high temperatures, affecting its application. Existing modification methods have problems such as uneven filler dispersion, decreased transparency and excessively high processing temperatures.
By treating modified montmorillonite and glass fiber, combining polycarbonate and compatibilizer, and adopting in-situ polymerization and melt extrusion processes, a heat-resistant polymethyl methacrylate composite material is formed. The layered structure of montmorillonite is used to block heat transfer, and the rigid skeleton of glass fiber is used to improve the thermal stability and interface compatibility of the material.
The heat resistance and processability of the polymethyl methacrylate composite material are improved to form an optical film material with good thermal stability.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of polymethyl methacrylate materials and relates to a heat-resistant polymethyl methacrylate composite material and a preparation method thereof. Background Art
[0002] Polymethyl methacrylate (PMMA) is widely used in various fields due to its high transparency and weather resistance. However, PMMA has poor heat resistance, degrading at temperatures reaching 150°C and significantly degrading at 250°C. Since PMMA typically requires extrusion or injection molding at temperatures between 220°C and 250°C, its poor heat resistance severely impacts its applications.
[0003] Existing technologies improve heat resistance through copolymerization, addition of inorganic fillers or cross-linking modification, but there are the following problems: uneven dispersion of fillers leads to decreased mechanical properties, excessive fillers impair transparency, and excessive processing temperature causes PMMA decomposition.
[0004] Therefore, there is an urgent need for a heat-resistant polymethyl methacrylate composite material with excellent heat resistance. Summary of the Invention
[0005] The object of the present invention is to provide a heat-resistant polymethyl methacrylate composite material and a preparation method thereof. The prepared polymethyl methacrylate composite material has excellent heat resistance.
[0006] The purpose of the present invention can be achieved through the following technical solutions: A heat-resistant polymethyl methacrylate composite material comprises the following components in parts by weight: 80-100 parts of modified polymethyl methacrylate, 40-50 parts of polycarbonate, 20-30 parts of modified glass fiber, 1-3 parts of a compatibilizer, 1-2 parts of a lubricant, 1-2.5 parts of a coupling agent, and 1-3 parts of an antioxidant, wherein the modified glass fiber is pretreated with a solution and then treated with 3-phenyl-cyclobutanecarboxylic acid to obtain the composite material; The preparation process of the modified polymethyl methacrylate is as follows: S11, calcining the montmorillonite at 180° C. for 3-5 hours, and then grinding the montmorillonite in a ball mill at a speed of 400 r / min for 3 hours to obtain a pretreated montmorillonite; S12. Mix methyl methacrylate, pretreated montmorillonite and azobisisobutyronitrile in a mass ratio of 50:2:(0.4~0.5), stir at a speed of 300 r / min for 45~60 min in a nitrogen atmosphere at 80°C, cool to room temperature after stirring, and then dry in a vacuum drying oven at 60°C for 8 h to obtain the modified polymethyl methacrylate.
[0007] Furthermore, the preparation process of the modified glass fiber is as follows: S21, mixing glass fiber and acid solution in a mass ratio of 1:(10-15), heating to 40-50°C, stirring at a speed of 400 r / min for 2-3 hours, filtering, washing with deionized water, and drying to obtain pretreated glass fiber; S22. In parts by weight, mix 20 to 25 parts of 3-phenyl-cyclobutanecarboxylic acid and 70 parts of chloroform evenly, then add 38 to 43 parts of pretreated glass fiber and 1 part of concentrated sulfuric acid, stir at 65°C and 400 r / min for 2 to 3 hours, filter, and dry to obtain modified glass fiber.
[0008] Furthermore, the compatibilizer is one of polyethylene-maleic anhydride copolymer, polypropylene-maleic anhydride copolymer and polyacrylic acid resin.
[0009] Furthermore, the lubricant is one of calcium stearate, benzyl silicone oil and polyethylene wax.
[0010] Furthermore, the coupling agent is one of the silane coupling agents KH550 and KH560.
[0011] Furthermore, the antioxidant is one of antioxidant 1010, antioxidant 1076 and antioxidant 168.
[0012] Furthermore, the acid solution is a hydrochloric acid solution with a concentration of 1 to 2.5 mol / L.
[0013] A method for preparing a heat-resistant polymethyl methacrylate composite material comprises the following steps: S1. Mix modified polymethyl methacrylate and polycarbonate in parts by weight, add dibutyltin dilaurate at a temperature of 260° C., and stir at a speed of 300 r / min for 30 minutes to obtain a mixture A; S2. Mixing mixture A with tetrahydrofuran, precipitating with ethyl acetate, filtering, washing, and drying at 40° C. for 5 h to obtain mixture B; S3. The modified glass fiber, compatibilizer, lubricant, coupling agent and antioxidant are mixed, ball milled at a speed of 400 r / min for 30 min, and then mixed with mixture B. The mixture is melt-extruded to obtain the heat-resistant polymethyl methacrylate composite material.
[0014] Furthermore, in step S1, the amount of dibutyltin dilaurate is 1-2% of the mass of the modified polymethyl methacrylate.
[0015] Furthermore, in step S2, the ratio of the mixture A to tetrahydrofuran is 1:40 g / mL.
[0016] In the present invention, modified polymethyl methacrylate is prepared by in-situ polymerization. First, montmorillonite is pretreated, and adsorbed water, crystal water and organic impurities between montmorillonite layers are removed by roasting to expand the interlayer spacing. The montmorillonite particle size is refined by grinding to increase the specific surface area and improve the contact area with the polymethyl methacrylate matrix.
[0017] Through in-situ polymerization, the montmorillonite flakes can limit the molecular chain movement of the polymer, reduce phase separation, and thus improve the overall thermal stability of the composite material. At the same time, montmorillonite improves thermal stability through compounding, and the layered structure of montmorillonite can block heat transfer and delay decomposition, thereby utilizing the thermal barrier effect to improve heat resistance.
[0018] Because PMMA alone has poor heat resistance, modified glass fiber is added to utilize its rigid skeleton to inhibit the high-temperature motion of the PMMA molecular chains, reducing deformation and improving heat resistance. However, because glass fiber is hydrophilic and PMMA is hydrophobic, traditional blending processes can lead to poor interfacial bonding, resulting in delamination or stress concentration, which impacts mechanical properties. Furthermore, the processing temperature of PMMA is relatively low, while glass fiber requires higher temperatures for uniform dispersion, resulting in poor processability.
[0019] Therefore, the present invention modifies the glass fiber by first removing inorganic impurities on the surface of the glass fiber with acid to activate the surface hydroxyl groups, and then treating the glass fiber with activated surface hydroxyl groups with 3-phenyl-cyclobutanecarboxylic acid. Therefore, through the combination, the interfacial compatibility between the glass fiber and the composite material can be improved and stress concentration can be reduced. At the same time, the cyclic structure brought by the 3-phenyl-cyclobutanecarboxylic acid can delay thermal decomposition and enhance the overall thermal stability.
[0020] Modified polymethyl methacrylate and polycarbonate are blended and stirred to form a compatible system, which combines the properties of both and helps improve the heat resistance of the composite material. Furthermore, dibutyltin dilaurate can help promote the transesterification of polymethyl methacrylate and polycarbonate, thereby enhancing interfacial bonding. The process of the present invention also helps inhibit phase separation due to the presence of montmorillonite in the modified polymethyl methacrylate. The nanosheets of montmorillonite hinder the macroscopic phase separation of the polymethyl methacrylate and polycarbonate molecular chains, forming a more uniform microscopic co-continuous phase. This can solve the core problems of direct blending, such as poor compatibility, low thermal stability, and a narrow processing window, and achieve more stable heat resistance.
[0021] Beneficial effects of the present invention: The present invention uses polymethyl methacrylate obtained by in-situ polymerization of montmorillonite as a base material and introduces heat-resistant and high-toughness polycarbonate, so that the optical film material obtained after blending has good heat resistance. The benzene ring structure introduced into the modified glass fiber is added to delay thermal decomposition and enhance the overall thermal stability, and together with the various components, a heat-resistant polymethyl methacrylate composite material is obtained. DETAILED DESCRIPTION
[0022] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.
[0023] In the following examples and comparative examples: Montmorillonite: purchased from Shanghai Kanglang Biotechnology Co., Ltd., product number: KL813516; methyl methacrylate: purchased from Wuhan Kanos Technology Co., Ltd.; azobisisobutyronitrile: purchased from Shandong Yukang Chemical Co., Ltd.; glass fiber: purchased from Shanghai Mairui Biochemical Technology Co., Ltd., product number: M65987; 3-phenyl-cyclobutanecarboxylic acid: purchased from Zhengzhou Huiju Chemical Co., Ltd., product number: A016282; polycarbonate: purchased from Jiangsu Congzhong Chemical Co., Ltd., product number: 12096; dibutyltin dilaurate: purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number: D100274; polyethylene-maleic anhydride copolymer: purchased from Shanghai Maclean Biochemical Technology Co., Ltd., product number: P875047; calcium stearate: purchased from Shanghai Maclean Biochemical Technology Co., Ltd., product number: C805417; KH550: purchased from Shanghai Yuanye Biotechnology Co., Ltd.; antioxidant 168: purchased from Hubei Wonder Chemical Co., Ltd.
[0024] Example 1
[0025] Preparation of modified polymethyl methacrylate: S11, calcining the montmorillonite at 180° C. for 3 h, and then grinding the montmorillonite in a ball mill at a speed of 400 r / min for 3 h to obtain a pretreated montmorillonite; S12. Mix methyl methacrylate, pretreated montmorillonite and azobisisobutyronitrile in a mass ratio of 50:2:0.4, stir at a speed of 300 r / min for 45 minutes under a nitrogen atmosphere at 80°C, cool to room temperature after stirring, and then dry in a vacuum drying oven at 60°C for 8 hours to obtain the modified polymethyl methacrylate.
[0026] Preparation of modified glass fiber: S21, mixing glass fibers with a mass ratio of 1:10 and a 1 mol / L hydrochloric acid solution, heating to 40° C. and stirring at a speed of 400 r / min for 2 h, filtering after stirring, washing with deionized water, and drying at 80° C. for 10 h to obtain pretreated glass fibers; S22. In parts by weight, 20 parts of 3-phenyl-cyclobutanecarboxylic acid and 70 parts of chloroform were mixed evenly, and then 38 parts of pretreated glass fiber and 1 part of concentrated sulfuric acid were added. The mixture was stirred at a speed of 400 r / min at 65°C for 2 hours, filtered, and dried at 80°C for 10 hours to obtain modified glass fiber.
[0027] Preparation of heat-resistant polymethyl methacrylate composite materials: S1. Mix 80 parts of modified polymethyl methacrylate and 40 parts of polycarbonate by weight, add 1% by weight of dibutyltin dilaurate based on the weight of the modified polymethyl methacrylate at 260° C., and stir at 300 rpm for 30 min to obtain a mixture A. S2. Mixing mixture A with tetrahydrofuran, heating under reflux for 1 h, and then pouring into ethyl acetate under stirring for precipitation, stirring and dispersing, filtering to remove the filtrate, and repeatedly washing with ethyl acetate 3-5 times, and drying at 40° C. for 5 h to obtain mixture B, wherein the amount ratio of mixture A to tetrahydrofuran is 1:40 g / mL; S3. Mix 20 parts of modified glass fiber, 1 part of polyethylene-maleic anhydride copolymer, 1 part of calcium stearate, 1 part of KH550 and 1 part of antioxidant 168, ball mill them at a speed of 400 r / min for 30 minutes, and then mix them with mixture B. After melt extrusion and granulation, the heat-resistant polymethyl methacrylate composite material is obtained.
[0028] The melt extrusion process uses a twin-screw machine with the following temperature zones: zone 1 temperature 200°C, zone 210°C, zone 3 temperature 220°C, zone 4 temperature 240°C, zone 5 temperature 250°C, zone 6 temperature 250°C, zone 7 temperature 250°C, zone 8 temperature 250°C, zone 9 temperature 250°C, zone 10 temperature 250°C, die head temperature 250°C, and speed 300 rpm.
[0029] Example 2
[0030] Preparation of modified polymethyl methacrylate: S11, calcining the montmorillonite at 180° C. for 3-5 hours, and then grinding the montmorillonite in a ball mill at a speed of 400 r / min for 3 hours to obtain a pretreated montmorillonite; S12. Mix methyl methacrylate, pretreated montmorillonite and azobisisobutyronitrile in a mass ratio of 50:2:0.45, stir at a speed of 300 r / min for 50 minutes under a nitrogen atmosphere at 80°C, cool to room temperature after stirring, and then dry in a vacuum drying oven at 60°C for 8 hours to obtain the modified polymethyl methacrylate.
[0031] Preparation of modified glass fiber: S21, mixing glass fibers with a mass ratio of 1:13 and a 2 mol / L hydrochloric acid solution, heating to 45° C. and stirring at a speed of 400 r / min for 2.5 h, filtering, washing with deionized water, and drying to obtain pretreated glass fibers; S22. In parts by weight, 23 parts of 3-phenyl-cyclobutanecarboxylic acid and 70 parts of chloroform were mixed evenly, and then 40 parts of pretreated glass fiber and 1 part of concentrated sulfuric acid were added. The mixture was stirred at 400 r / min at 65°C for 2.5 hours, filtered, and dried at 80°C for 10 hours to obtain modified glass fiber.
[0032] Preparation of heat-resistant polymethyl methacrylate composite materials: S1. Mix 90 parts of modified polymethyl methacrylate and 45 parts of polycarbonate by weight, add 1.5% dibutyltin dilaurate by weight of the modified polymethyl methacrylate at 260° C., and stir at 300 rpm for 30 min to obtain a mixture A. S2. Mixing mixture A with tetrahydrofuran, heating under reflux for 1 h, and then pouring into ethyl acetate under stirring for precipitation, stirring and dispersing, filtering to remove the filtrate, and repeatedly washing with ethyl acetate 3-5 times, and drying at 40° C. for 5 h to obtain mixture B, wherein the amount ratio of mixture A to tetrahydrofuran is 1:40 g / mL; S3. Mix 25 parts of modified glass fiber, 2 parts of polyethylene-maleic anhydride copolymer, 1.5 parts of calcium stearate, 2 parts of KH550 and 2 parts of antioxidant 168, ball mill them at a speed of 400 r / min for 30 minutes, and then mix them with mixture B. After melt extrusion and granulation, the heat-resistant polymethyl methacrylate composite material is obtained.
[0033] The melt extrusion process is as follows: twin-screw machine temperature zones: zone 1 temperature 200°C, zone 2 temperature 210°C, zone 3 temperature 220°C, zone 4 temperature 240°C, zone 5 temperature 250°C, zone 6 temperature 260°C, zone 7 temperature 250°C, zone 8 temperature 250°C, zone 9 temperature 250°C, zone 10 temperature 250°C, die head temperature 250°C, speed 300rpm.
[0034] Example 3
[0035] Preparation of modified polymethyl methacrylate: S11, calcining the montmorillonite at 180° C. for 5 h, and then grinding the montmorillonite in a ball mill at a speed of 400 r / min for 3 h to obtain a pretreated montmorillonite; S12. Mix methyl methacrylate, pretreated montmorillonite and azobisisobutyronitrile in a mass ratio of 50:2:0.5, stir at a speed of 300 r / min for 60 min in a nitrogen atmosphere at 80°C, cool to room temperature after stirring, and then dry in a vacuum drying oven at 60°C for 8 h to obtain the modified polymethyl methacrylate.
[0036] Preparation of modified glass fiber: S21, mixing glass fibers and 2.5 mol / L hydrochloric acid solution in a mass ratio of 1:15, heating to 50° C. and stirring at a speed of 400 r / min for 3 h, filtering, washing with deionized water, and drying to obtain pretreated glass fibers; S22. In parts by weight, 25 parts of 3-phenyl-cyclobutanecarboxylic acid and 70 parts of chloroform were mixed evenly, and then 43 parts of pretreated glass fiber and 1 part of concentrated sulfuric acid were added. The mixture was stirred at a speed of 400 r / min at 65°C for 3 hours, filtered, and dried at 80°C for 10 hours to obtain modified glass fiber.
[0037] Preparation of heat-resistant polymethyl methacrylate composite materials: S1. Mix 100 parts of modified polymethyl methacrylate and 50 parts of polycarbonate by weight, add 2% by weight of dibutyltin dilaurate based on the weight of the modified polymethyl methacrylate at 260° C., and stir at 300 rpm for 30 min to obtain a mixture A. S2. Mixing mixture A with tetrahydrofuran, heating under reflux for 1 h, and then pouring into ethyl acetate under stirring for precipitation, stirring and dispersing, filtering to remove the filtrate, and repeatedly washing with ethyl acetate 3-5 times, and drying at 40° C. for 5 h to obtain mixture B, wherein the amount ratio of mixture A to tetrahydrofuran is 1:40 g / mL; S3. Mix 30 parts of modified glass fiber, 3 parts of polyethylene-maleic anhydride copolymer, 2 parts of calcium stearate, 2.5 parts of KH550 and 3 parts of antioxidant 168, ball mill them at a speed of 400 r / min for 30 minutes, and then mix them with mixture B. After melt extrusion and granulation, the heat-resistant polymethyl methacrylate composite material is obtained.
[0038] The melt extrusion process is as follows: twin-screw machine temperature zones: zone 1 temperature 200°C, zone 2 temperature 210°C, zone 3 temperature 220°C, zone 4 temperature 240°C, zone 5 temperature 250°C, zone 6 temperature 260°C, zone 7 temperature 250°C, zone 8 temperature 250°C, zone 9 temperature 250°C, zone 10 temperature 250°C, die head temperature 250°C, speed 300rpm.
[0039] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the polymethyl methacrylate added during the preparation of the heat-resistant polymethyl methacrylate composite material in Comparative Example 1 has not been modified, that is, has not been treated with montmorillonite, and the other operations are the same.
[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the glass fiber in Comparative Example 2 is not modified with 3-phenyl-cyclobutanecarboxylic acid, and the other operations are the same.
[0041] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the polycarbonate treatment is not performed in Comparative Example 3, and the other operations are the same.
[0042] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that in Comparative Example 4, the heat-resistant polymethyl methacrylate composite material was prepared as follows: 80 parts of polymethyl methacrylate, 20 parts of modified glass fiber, 1 part of polyethylene-maleic anhydride copolymer, 1 part of calcium stearate, 1 part of KH550 and 1 part of antioxidant 168 were mixed by weight, ball milled at a speed of 400 r / min for 30 minutes, and then mixed with mixture B. The heat-resistant polymethyl methacrylate composite material was obtained by melt blending at 260°C, extruding and granulating.
[0043] Performance testing: The heat-resistant polymethyl methacrylate materials provided in Examples 1-3 and Comparative Examples 1-4 were tested.
[0044] Tensile strength: tested according to ASTM D638, with a tensile speed of 50 mm / min; Vicat softening temperature: Measured according to ASTM D1525-2017 Standard Test Method for Vicat Softening Temperature of Plastics, with a weight of 10±0.2N and a heating rate of 50±5°C / h. The Vicat softening temperature is recorded as the temperature when the indenter penetrates the sample by 1±0.01mm. The test results are shown in the following table: Group Tensile strength / MPa Vicat softening temperature / ℃ Example 1 71 124 Example 2 75 128 Example 3 72 125 Comparative Example 1 68 120 Comparative Example 2 69 121 Comparative Example 3 66 115 Comparative Example 4 64 112 According to the above data, it can be seen that the heat-resistant polymethyl methacrylate composite material prepared in the present invention has excellent heat resistance.
[0045] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A heat-resistant polymethyl methacrylate composite material, characterized in that: The invention comprises the following components in parts by weight: 80-100 parts of modified polymethyl methacrylate, 40-50 parts of polycarbonate, 20-30 parts of modified glass fiber, 1-3 parts of a compatibilizer, 1-2 parts of a lubricant, 1-2.5 parts of a coupling agent and 1-3 parts of an antioxidant, wherein the modified glass fiber is prepared by pre-treating the solution of the modified glass fiber and then treating the modified glass fiber with 3-phenyl-cyclobutane carboxylic acid. The preparation process of the modified polymethyl methacrylate is as follows: S11, calcining the montmorillonite at 180° C. for 3-5 hours, and then grinding the montmorillonite in a ball mill at a speed of 400 r / min for 3 hours to obtain a pretreated montmorillonite; S12. Mix methyl methacrylate, pretreated montmorillonite and azobisisobutyronitrile in a mass ratio of 50:2:(0.4~0.5), stir at a speed of 300 r / min for 45~60 min in a nitrogen atmosphere at 80°C, cool to room temperature after stirring, and then dry in a vacuum drying oven at 60°C for 8 h to obtain the modified polymethyl methacrylate.
2. The heat-resistant polymethyl methacrylate composite material according to claim 1, characterized in that: The preparation process of the modified glass fiber is as follows: S21, mixing glass fiber and acid solution in a mass ratio of 1:(10-15), heating to 40-50°C, stirring at a speed of 400 r / min for 2-3 hours, filtering, washing with deionized water, and drying to obtain pretreated glass fiber; S22. In parts by weight, mix 20 to 25 parts of 3-phenyl-cyclobutanecarboxylic acid and 70 parts of chloroform evenly, then add 38 to 43 parts of pretreated glass fiber and 1 part of concentrated sulfuric acid, stir at 65°C and 400 r / min for 2 to 3 hours, filter, and dry to obtain modified glass fiber.
3. The heat-resistant polymethyl methacrylate composite material according to claim 1, characterized in that: The compatibilizer is one of polyethylene-maleic anhydride copolymer, polypropylene-maleic anhydride copolymer and polyacrylic acid resin.
4. The heat-resistant polymethyl methacrylate composite material according to claim 1, characterized in that: The lubricant is one of calcium stearate, benzyl silicone oil and polyethylene wax.
5. The heat-resistant polymethyl methacrylate composite material according to claim 1, characterized in that: The coupling agent is one of silane coupling agents KH550 and KH560.
6. The heat-resistant polymethyl methacrylate composite material according to claim 1, characterized in that: The antioxidant is one of antioxidant 1010, antioxidant 1076 and antioxidant 168.
7. The heat-resistant polymethyl methacrylate composite material according to claim 2, characterized in that: The acid solution is a hydrochloric acid solution with a concentration of 1-2.5 mol / L.
8. A method for preparing the heat-resistant polymethyl methacrylate composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Mix modified polymethyl methacrylate and polycarbonate in parts by weight, add dibutyltin dilaurate at a temperature of 260° C., and stir at a speed of 300 r / min for 30 minutes to obtain a mixture A; S2. Mixing mixture A with tetrahydrofuran, precipitating with ethyl acetate, filtering, washing, and drying at 40° C. for 5 h to obtain mixture B; S3. The modified glass fiber, compatibilizer, lubricant, coupling agent and antioxidant are mixed, ball milled at a speed of 400 r / min for 30 min, and then mixed with mixture B. The mixture is melt-extruded to obtain the heat-resistant polymethyl methacrylate composite material.
9. The method for preparing the heat-resistant polymethyl methacrylate composite material according to claim 8, characterized in that: In step S1, the amount of dibutyltin dilaurate used is 1-2% of the mass of the modified polymethyl methacrylate.
10. The method for preparing the heat-resistant polymethyl methacrylate composite material according to claim 8, characterized in that: In step S2, the ratio of the mixture A to tetrahydrofuran is 1:40 g / mL.