High-strength modified polypropylene composite material and preparation process thereof
By combining thiazole-based phosphorus-containing flame retardants with modified glass fibers, the flame retardancy and weather resistance issues of glass fiber reinforced polypropylene composites were solved, and the flame retardancy and weather resistance properties of high-strength modified polypropylene composites were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN XINGBAOCHANG IND CO LTD
- Filing Date
- 2026-03-05
- Publication Date
- 2026-05-12
AI Technical Summary
Glass fiber reinforced polypropylene composites have poor flame retardancy and insufficient weather resistance, which affects their safety and service life in applications such as building materials, automobiles, packaging and furniture.
The flame retardant properties are improved by chemically modifying the composite of thiazole-based phosphorus-containing flame retardant and modified glass fiber; amino and hindered phenolic structures are introduced on the surface of the glass fiber to enhance its weather resistance.
It significantly improves the flame retardancy and weather resistance of polypropylene composites, and enhances the mechanical properties and service life of the materials.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polypropylene composite materials technology, specifically to a high-strength modified polypropylene composite material and its preparation process. Background Technology
[0002] Polypropylene composites refer to multiphase solid materials made by compounding or mixing polypropylene with one or more other materials using polypropylene as the matrix resin. Through modification methods such as filling, reinforcement, and blending, the performance boundaries of polypropylene have been greatly expanded, upgrading it from a general-purpose plastic to an engineering plastic that meets various demanding requirements. Glass fiber reinforced polypropylene composites have been extensively studied and reported, and the technology is relatively mature, with widespread applications in machinery, electronics, chemicals, construction, and aerospace.
[0003] Glass fiber reinforced polypropylene composites have poor flame retardant properties, with a limiting oxygen index below 20%, classifying them as flammable materials and posing significant safety hazards in practical applications. As the market demand for polypropylene composites in building materials, automobiles, packaging, and furniture gradually increases, research on the flame retardancy of glass fiber reinforced polypropylene composites has significant practical value for fire prevention, disaster mitigation, and improving the safety of civilian materials.
[0004] On the other hand, glass fiber reinforced polypropylene composites are prone to aging under the influence of light, heat, and oxygen. This is especially true for composites used outdoors for extended periods, where light, heat, and oxygen in the environment can exacerbate performance degradation and affect the service life of the composites.
[0005] To address the shortcomings of glass fiber reinforced polypropylene composites, chemical modification was performed on the glass fiber reinforced composites to improve their weather resistance and flame retardant properties. Summary of the Invention
[0006] The purpose of this invention is to provide a high-strength modified polypropylene composite material and its preparation process to solve the problems existing in the prior art.
[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:
[0008] A high-strength modified polypropylene composite material, comprising, by weight, 60-70 parts polypropylene, 15-18 parts modified glass fiber, and 5-6 parts thiazole-based phosphorus-containing flame retardant.
[0009] Preferably, the thiazole-based phosphorus-containing flame retardant is prepared by reacting phosphorus oxychloride sequentially with p-hydroxybenzaldehyde and 2-aminothiazole.
[0010] Preferably, the modified glass fiber is prepared by reacting aminated glass fiber, acrylate-based hindered phenol, and 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate.
[0011] Preferably, the aminated glass fiber is prepared by reacting glass fiber sequentially with 3-chloropropyltriethoxysilane and tetraethylenepentamine.
[0012] Preferably, the acrylate-based hindered phenol is prepared by reacting 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate.
[0013] A preparation process for a high-strength modified polypropylene composite material, the preparation process of the high-strength modified polypropylene composite material includes the following steps:
[0014] (1) The intermediate and 2-aminothiazole were added to 1,6-dioxane at a molar ratio of 1:3, which was 12 to 16 times the mass of the intermediate. The mixture was stirred at 75 to 85°C for 3 to 4 hours and then dried under vacuum at 70 to 80°C for 7 to 8 hours to obtain a thiazole-based phosphorus-containing flame retardant.
[0015] (2) Under nitrogen protection, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate were dissolved in benzene at a molar ratio of 1:1 in 5 to 6 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol. The mixture was stirred for 10 to 20 minutes, and then 0.001 to 0.002 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol in dibutyltin dilaurate was added. The mixture was stirred at 30 to 40 °C for 5 to 6 hours. The mixture was then distilled under reduced pressure to obtain acrylate-based hindered phenol.
[0016] (3) Aminated glass fiber, acrylate-based hindered phenol, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate, and N,N-dimethylformamide are mixed evenly in a mass ratio of 1:(0.4~0.6):(0.5~0.7):(30~40), stirred at 50~60℃ for 8~10h, centrifuged, washed 3 times with anhydrous ethanol and deionized water, and vacuum dried at 80~90℃ for 16~20h to obtain modified glass fiber;
[0017] (4) Weigh 60-70 parts of polypropylene, 15-18 parts of modified glass fiber, and 5-6 parts of thiazole-based phosphorus-containing flame retardant; add polypropylene, modified glass fiber, and thiazole-based phosphorus-containing flame retardant to a high-speed mixer, stir and mix at 300-400 r / min for 10-20 min, then place it in a rheometer to melt and plasticize, then place it on a flat vulcanizing machine for hot pressing and molding, and naturally cool to room temperature to obtain a high-strength modified polypropylene composite material.
[0018] Preferably, the intermediate in step (1) is prepared as follows: phosphorus oxychloride, p-hydroxybenzaldehyde, and triethylamine are weighed in a molar ratio of 1:3:3; p-hydroxybenzaldehyde and triethylamine are dissolved in tetrahydrofuran at 16-20 times the mass of p-hydroxybenzaldehyde, stirred at room temperature for 20-30 min, phosphorus oxychloride is added, and the mixture is stirred and refluxed at 60-66°C for 8-10 h under nitrogen protection. The mixture is extracted with deionized water and ethyl acetate, and the organic phase is dried under vacuum at 50-60°C for 10-12 h to obtain the intermediate.
[0019] Preferably, the chemical reaction formula of the thiazole-based phosphorus-containing flame retardant in step (1) is as follows:
[0020] .
[0021] Preferably, the chemical formula for the reaction of the acrylate-based hindered phenol in step (2) is as follows:
[0022] .
[0023] Preferably, the preparation method of the aminated glass fiber in step (3) is as follows: pre-modified glass fiber and N,N-dimethylformamide are mixed evenly at a mass ratio of 1:(40~50), tetraethylenepentamine is added at a mass ratio of 2~2.4 times that of the pre-modified glass fiber, the mixture is stirred at 50~60℃ for 3~4h, centrifuged, washed 3 times with anhydrous ethanol and deionized water, and vacuum dried at 70~80℃ for 10~12h to obtain aminated glass fiber.
[0024] Preferably, the pre-modified glass fiber is prepared by mixing glass fiber, anhydrous ethanol, and deionized water in a mass ratio of 1:(40~50):(10~14), sonicating for 1~2 hours, adding 1.2~1.6 times the mass of the glass fiber of 3-chloropropyltriethoxysilane, stirring and reacting at 60~70°C for 4~6 hours, centrifuging, washing three times with anhydrous ethanol and deionized water, and vacuum drying at 50~60°C for 10~12 hours to obtain the pre-modified glass fiber.
[0025] Preferably, the melting and plasticizing process conditions in step (4) are: 200~210℃, stirring at 40~100r / min for 6~8min; the hot pressing process conditions are: 190~196℃, hot pressing at 9~11MPa for 5~6min.
[0026] The beneficial effects achieved by this invention are as follows:
[0027] 1. Phosphorus oxychloride was reacted sequentially with p-hydroxybenzaldehyde and 2-aminothiazole to prepare a thiazole-based phosphorus-containing flame retardant. The thiazole five-membered ring contains sulfur and nitrogen elements, which have excellent char-forming ability. At the same time, sulfur decomposes at high temperature to produce non-flammable sulfur-containing gas, which has a certain flame retardant effect. The combination of thiazole and phosphorus elements produces a synergistic effect, which jointly improves the flame retardant ability of polypropylene composite materials.
[0028] 2. Aminated glass fibers are prepared by reacting glass fibers sequentially with 3-chloropropyltriethoxysilane and tetraethylenepentamine, introducing a large amount of primary and secondary amines onto the surface of the glass fibers. Then, the amino groups on the aminated glass fibers undergo a Michael reaction with the hindered acrylate groups of phenol and acrylate groups on 2-[3-(2H-benzotriazole-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate to obtain modified glass fibers. A large number of hindered phenol and benzotriazole structures are grafted onto the surface of the modified glass fibers. Benzotriazole UV absorbers can absorb ultraviolet light, and hindered phenol structures can capture free radicals and terminate chain reactions. The synergistic effect of the two improves the weather resistance of polypropylene composites. Detailed Implementation
[0029] 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.
[0030] Raw material information:
[0031] Glass fiber: chopped glass fiber, model dbx-1, Hebei Wensheng New Material Technology Co., Ltd.;
[0032] Polypropylene: Y1600, China Petroleum & Chemical Corporation.
[0033] Example 1:
[0034] A preparation process for a high-strength modified polypropylene composite material includes the following preparation steps:
[0035] (1) Weigh phosphorus oxychloride, p-hydroxybenzaldehyde, and triethylamine in a molar ratio of 1:3:3; dissolve p-hydroxybenzaldehyde and triethylamine in tetrahydrofuran at 16 times the mass of p-hydroxybenzaldehyde, stir at room temperature for 20 min, add phosphorus oxychloride, and reflux at 60°C for 10 h under nitrogen protection. Extract with deionized water and ethyl acetate, take the organic phase, and vacuum dry at 50°C for 12 h to obtain the intermediate; add the intermediate and 2-aminothiazole in a molar ratio of 1:3 to 1,6-dioxane at 12 times the mass of the intermediate, stir at 75°C for 4 h, and vacuum dry at 70°C for 8 h to obtain the thiazole-based phosphorus-containing flame retardant;
[0036] (2) Under nitrogen protection, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate were dissolved in benzene at a molar ratio of 1:1 to 5 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol. The mixture was stirred at room temperature for 10 min, and then 0.001 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol to dibutyltin dilaurate were added. The mixture was stirred at 30 °C for 6 h, and then distilled under reduced pressure to obtain acrylate-based hindered phenol.
[0037] (3) Glass fiber, anhydrous ethanol, and deionized water were mixed in a mass ratio of 1:40:10 and sonicated for 1 hour. 1.2 times the mass of the glass fiber was added to 3-chloropropyltriethoxysilane and stirred at 60°C for 6 hours. After centrifugation, the mixture was washed three times with anhydrous ethanol and deionized water and dried under vacuum at 50°C for 12 hours to obtain pre-modified glass fiber. Pre-modified glass fiber and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:40 and tetraethylenepentamine was added in a mass ratio of 2 times the mass of the pre-modified glass fiber. The mixture was stirred at 50°C for 4 hours. The mixture was centrifuged, washed three times with anhydrous ethanol and deionized water, and vacuum dried at 70℃ for 12 h to obtain aminated glass fiber. Aminated glass fiber, acrylate-hindered phenol, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:0.4:0.5:30, stirred and reacted at 50℃ for 10 h, centrifuged, washed three times with anhydrous ethanol and deionized water, and vacuum dried at 80℃ for 20 h to obtain modified glass fiber.
[0038] (4) Weigh 60 parts of polypropylene, 15 parts of modified glass fiber, and 5 parts of thiazole-based phosphorus-containing flame retardant; add polypropylene, modified glass fiber, and thiazole-based phosphorus-containing flame retardant to a high-speed mixer, stir and mix at 300 r / min for 20 min, then place in a rheometer, stir at 200℃ and 40 r / min for 8 min, place on a flat vulcanizing machine, hot press at 190℃ and 9 MPa for 6 min, and cool naturally to room temperature to obtain a high-strength modified polypropylene composite material.
[0039] Example 2:
[0040] A preparation process for a high-strength modified polypropylene composite material includes the following preparation steps:
[0041] (1) Weigh phosphorus oxychloride, p-hydroxybenzaldehyde, and triethylamine in a molar ratio of 1:3:3; dissolve p-hydroxybenzaldehyde and triethylamine in tetrahydrofuran at 18 times the mass of p-hydroxybenzaldehyde, stir at room temperature for 25 min, add phosphorus oxychloride, and reflux at 63°C for 9 h under nitrogen protection. Extract with deionized water and ethyl acetate, take the organic phase, and vacuum dry at 55°C for 11 h to obtain the intermediate; add the intermediate and 2-aminothiazole in a molar ratio of 1:3 to 1,6-dioxane at 14 times the mass of the intermediate, stir at 80°C for 3.5 h, and vacuum dry at 75°C for 7.5 h to obtain the thiazole-based phosphorus-containing flame retardant;
[0042] (2) Under nitrogen protection, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate were dissolved in benzene at a molar ratio of 1:1 in 5.5 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol. The mixture was stirred at room temperature for 15 min, and then dibutyltin dilaurate was added at a molar ratio of 0.0015 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol. The mixture was stirred at 35 °C for 5.5 h, and then distilled under reduced pressure to obtain acrylate-based hindered phenol.
[0043] (3) Glass fiber, anhydrous ethanol, and deionized water were mixed in a mass ratio of 1:45:12 and sonicated for 1.5 h. 1.4 times the mass of the glass fiber was added to 3-chloropropyltriethoxysilane, and the mixture was stirred at 65 °C for 5 h. After centrifugation, the mixture was washed three times with anhydrous ethanol and deionized water, and then vacuum dried at 55 °C for 11 h to obtain pre-modified glass fiber. Pre-modified glass fiber and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:45. 2.2 times the mass of the pre-modified glass fiber was added to tetraethylenepentamine, and the mixture was stirred at 55 °C for 3 h. After centrifugation for 0.5 h, the mixture was washed three times with anhydrous ethanol and deionized water, and then vacuum dried at 75 °C for 11 h to obtain aminated glass fiber. Aminated glass fiber, acrylate-hedged phenol, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate, and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:0.5:0.6:35, stirred at 55 °C for 9 h, centrifuged, washed three times with anhydrous ethanol and deionized water, and then vacuum dried at 85 °C for 18 h to obtain modified glass fiber.
[0044] (4) Weigh 65 parts of polypropylene, 16.5 parts of modified glass fiber, and 5.5 parts of thiazole-based phosphorus-containing flame retardant; add polypropylene, modified glass fiber, and thiazole-based phosphorus-containing flame retardant to a high-speed mixer, stir and mix at 350 r / min for 15 min, then place in a rheometer, stir at 205℃ and 70 r / min for 7 min, place on a flat vulcanizing machine, hot press at 193℃ and 10 MPa for 5.5 min, and cool naturally to room temperature to obtain a high-strength modified polypropylene composite material.
[0045] Example 3:
[0046] A preparation process for a high-strength modified polypropylene composite material includes the following preparation steps:
[0047] (1) Weigh phosphorus oxychloride, p-hydroxybenzaldehyde, and triethylamine in a molar ratio of 1:3:3; dissolve p-hydroxybenzaldehyde and triethylamine in tetrahydrofuran at 20 times the mass of p-hydroxybenzaldehyde, stir at room temperature for 30 min, add phosphorus oxychloride, and reflux at 66°C under nitrogen protection for 8 h, extract with deionized water and ethyl acetate, take the organic phase, and vacuum dry at 60°C for 10 h to obtain the intermediate; add the intermediate and 2-aminothiazole in a molar ratio of 1:3 to 1,6-dioxane at 16 times the mass of the intermediate, stir at 85°C for 3 h, and vacuum dry at 80°C for 7 h to obtain the thiazole-based phosphorus-containing flame retardant;
[0048] (2) Under nitrogen protection, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate were dissolved in benzene at a molar ratio of 1:1 to 6 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol. The mixture was stirred at room temperature for 20 min, and then 0.002 times the mass of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol to dibutyltin dilaurate were added. The mixture was stirred at 40 °C for 5 h, and then distilled under reduced pressure to obtain acrylate-based hindered phenol.
[0049] (3) Glass fiber, anhydrous ethanol, and deionized water were mixed in a mass ratio of 1:50:14 and sonicated for 2 hours. 1.6 times the mass of the glass fiber was added to 3-chloropropyltriethoxysilane, and the mixture was stirred at 70°C for 4 hours. After centrifugation, the mixture was washed three times with anhydrous ethanol and deionized water, and then vacuum dried at 60°C for 10 hours to obtain pre-modified glass fiber. The pre-modified glass fiber and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:50. 2.4 times the mass of the pre-modified glass fiber was added to tetraethylenepentamine, and the mixture was stirred at 60°C for 3 hours. h, centrifuge, wash three times with anhydrous ethanol and deionized water, and vacuum dry at 80℃ for 10h to obtain aminated glass fiber; mix aminated glass fiber, acrylate-hedged phenol, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate and N,N-dimethylformamide in a mass ratio of 1:0.6:0.7:40, stir and react at 60℃ for 8h, centrifuge, wash three times with anhydrous ethanol and deionized water, and vacuum dry at 90℃ for 16h to obtain modified glass fiber;
[0050] (4) Weigh 70 parts of polypropylene, 18 parts of modified glass fiber, and 6 parts of thiazole-based phosphorus-containing flame retardant; add polypropylene, modified glass fiber, and thiazole-based phosphorus-containing flame retardant to a high-speed mixer, stir and mix at 400 r / min for 10 min, then place in a rheometer, stir at 210℃ and 100 r / min for 6 min, place on a flat vulcanizing machine, hot press at 196℃ and 11 MPa for 5 min, and cool naturally to room temperature to obtain a high-strength modified polypropylene composite material.
[0051] Comparative Example 1:
[0052] The preparation process of the high-strength modified polypropylene composite material in Comparative Example 1 differs from that in Example 2 in that step (1) is omitted, and "thiazole-based phosphorus-containing flame retardant" is not added in step (4). The remaining steps are the same as in Example 2.
[0053] Comparative Example 2:
[0054] The difference between the preparation process of the high-strength modified polypropylene composite material in Comparative Example 2 and Example 2 is that step (2) is omitted, and step (3) is modified as follows: glass fiber, anhydrous ethanol, and deionized water are mixed in a mass ratio of 1:45:12, sonicated for 1.5 h, 3-chloropropyltriethoxysilane with a mass ratio of 1.4 times that of glass fiber is added, the mixture is stirred and reacted at 65 °C for 5 h, centrifuged, washed three times with anhydrous ethanol and deionized water, and vacuum dried at 55 °C for 11 h to obtain pre-modified glass fiber; the pre-modified glass fiber and N,N-dimethylformamide are mixed evenly in a mass ratio of 1:45. Add tetraethylenepentamine at a mass ratio of 2.2 times that of the pre-modified glass fiber, stir at 55°C for 3.5 h, centrifuge, wash three times with anhydrous ethanol and deionized water, and vacuum dry at 75°C for 11 h to obtain aminated glass fiber. Mix the aminated glass fiber, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate, and N,N-dimethylformamide at a mass ratio of 1:0.6:35, stir at 55°C for 9 h, centrifuge, wash three times with anhydrous ethanol and deionized water, and vacuum dry at 85°C for 18 h to obtain modified glass fiber. The remaining steps are the same as in Example 2.
[0055] Comparative Example 3:
[0056] The difference between the preparation process of the high-strength modified polypropylene composite material in Comparative Example 3 and Example 2 lies in step (3). Step (3) is modified as follows: glass fiber, anhydrous ethanol, and deionized water are mixed in a mass ratio of 1:45:12, sonicated for 1.5 h, 3-chloropropyltriethoxysilane (1.4 times the mass of glass fiber) is added, and the mixture is stirred at 65 °C for 5 h. After centrifugation, the mixture is washed three times with anhydrous ethanol and deionized water, and then vacuum dried at 55 °C for 11 h to obtain pre-modified glass fiber. The pre-modified glass fiber and N,N-dimethylformyl Amines were mixed evenly at a mass ratio of 1:45, and tetraethylenepentamine, in an amount 2.2 times the mass of the pre-modified glass fiber, was added. The mixture was stirred at 55°C for 3.5 hours, centrifuged, washed three times with anhydrous ethanol and deionized water, and vacuum dried at 75°C for 11 hours to obtain aminated glass fiber. Aminated glass fiber, acrylate-based hindered phenol, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:0.5:35, stirred at 55°C for 9 hours, centrifuged, washed three times with anhydrous ethanol and deionized water, and vacuum dried at 85°C for 18 hours to obtain modified glass fiber. The remaining steps were the same as in Example 2.
[0057] Comparative Example 4:
[0058] The preparation process of the high-strength modified polypropylene composite material in Comparative Example 4 differs from that in Example 2 in that step (3) is omitted and "modified glass fiber" is not added in step (4). The remaining steps are the same as in Example 2.
[0059] Performance testing
[0060] I. Mechanical property testing: The examples and comparative examples were prepared into Type I specimens according to the test methods of GB / T 1040—2006, and their tensile strength was tested at a tensile rate of 50 mm / min, denoted as X.
[0061] II. Weather Resistance Testing: Type I specimens were prepared according to the above mechanical property testing methods. The specimens were placed in a xenon lamp accelerated aging test chamber. The test conditions were: air atmosphere, temperature 65℃, xenon lamp wavelength 290~800nm, and radiation intensity 550W / m². 2 The distance between the lamp source and the sample was 25 cm, and the aging time was 400 hours. After the aging test, the sample was removed, and its tensile strength was tested using the same method, denoted as Y. The tensile strength retention rate of the examples and comparative examples was calculated. The tensile strength retention rate reflects the weather resistance of the sample. .
[0062] III. Flame retardant performance test: Referring to the test method of GB / T 2406.2-2009, the examples and comparative examples were prepared into 100×10×4mm samples, and the limiting oxygen index of the samples was tested.
[0063] The test results of the above performance tests are recorded in Table 1 below.
[0064] Table 1
[0065]
[0066] Analysis of the experimental data in Table 1 reveals that the tensile strength of Examples 1-3 is significantly higher than that of Comparative Example 4, the tensile strength retention rate of Examples 1-3 is significantly higher than that of Comparative Examples 2-4, and the limiting oxygen index of Examples 1-3 is significantly higher than that of Comparative Example 1. This indicates that the present invention obtains a thiazole-based phosphorus-containing flame retardant by reacting phosphorus oxychloride sequentially with p-hydroxybenzaldehyde and 2-aminothiazole; obtains an acrylate-based hindered phenol by reacting 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate; prepares aminated glass fiber by reacting glass fiber sequentially with 3-chloropropyltriethoxysilane and tetraethylenepentamine; prepares modified glass fiber by reacting aminated glass fiber, acrylate-based hindered phenol, and 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate; and improves the mechanical properties, flame retardant properties, and weather resistance of the polypropylene composite material by adding the thiazole-based phosphorus-containing flame retardant and the modified glass fiber to polypropylene.
[0067] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment 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 within the scope of protection of the present invention.
Claims
1. A high-strength modified polypropylene composite material, characterized in that, The high-strength modified polypropylene composite material comprises, by weight, 60-70 parts polypropylene, 15-18 parts modified glass fiber, and 5-6 parts thiazole-based phosphorus-containing flame retardant.
2. The high-strength modified polypropylene composite material as described in claim 1, characterized in that, The thiazole-based phosphorus-containing flame retardant is prepared by reacting phosphorus oxychloride sequentially with p-hydroxybenzaldehyde and 2-aminothiazole.
3. The high-strength modified polypropylene composite material as described in claim 1, characterized in that, The modified glass fiber is prepared by reacting aminated glass fiber, acrylate-based hindered phenol, and 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate.
4. The high-strength modified polypropylene composite material as described in claim 3, characterized in that, The aminated glass fiber is prepared by reacting glass fiber sequentially with 3-chloropropyltriethoxysilane and tetraethylenepentamine.
5. The high-strength modified polypropylene composite material as described in claim 3, characterized in that, The acrylate-based hindered phenol is prepared by reacting 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate.
6. A preparation process for a high-strength modified polypropylene composite material, characterized in that, The preparation process of the high-strength modified polypropylene composite material includes the following steps: (1) The intermediate and 2-aminothiazole were added to 1,6-dioxane at a molar ratio of 1:3, and the mixture was stirred at 75~85℃ for 3~4h and dried to obtain a thiazole-based phosphorus-containing flame retardant. (2) Under nitrogen protection, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and isocyanate methacrylate were dissolved in benzene at a molar ratio of 1:1, stirred at room temperature for 10-20 min, dibutyltin dilaurate was added, and the mixture was stirred at 30-40℃ for 5-6 h. The reaction was carried out by vacuum distillation to obtain acrylate-based hindered phenol. (3) Aminated glass fiber, acrylate-based hindered phenol, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate, and N,N-dimethylformamide are mixed evenly in a mass ratio of 1:(0.4~0.6):(0.5~0.7):(30~40), stirred at 50~60℃ for 8~10h, centrifuged, washed, and dried to obtain modified glass fiber; (4) Weigh 60-70 parts of polypropylene, 15-18 parts of modified glass fiber, and 5-6 parts of thiazole-based phosphorus-containing flame retardant; add polypropylene, modified glass fiber, and thiazole-based phosphorus-containing flame retardant to a high-speed mixer, stir and mix at 300-400 r / min for 10-20 min, then place it in a rheometer to melt and plasticize, then place it on a flat vulcanizing machine for hot pressing and molding, and naturally cool to room temperature to obtain a high-strength modified polypropylene composite material.
7. The preparation process of a high-strength modified polypropylene composite material as described in claim 6, characterized in that, The intermediate in step (1) is prepared as follows: phosphorus oxychloride, p-hydroxybenzaldehyde, and triethylamine are weighed in a molar ratio of 1:3:3; p-hydroxybenzaldehyde and triethylamine are dissolved in tetrahydrofuran and stirred at room temperature for 20-30 min; phosphorus oxychloride is added; under nitrogen protection, the mixture is stirred and refluxed at 60-66℃ for 8-10 h; the mixture is extracted with deionized water and ethyl acetate; the organic phase is collected and dried to obtain the intermediate.
8. The preparation process of a high-strength modified polypropylene composite material as described in claim 6, characterized in that, The preparation method of the aminated glass fiber in step (3) is as follows: pre-modified glass fiber and N,N-dimethylformamide are mixed evenly at a mass ratio of 1:(40~50), and tetraethylenepentamine is added at a mass ratio of 2~2.4 times that of the pre-modified glass fiber. The mixture is stirred and reacted at 50~60℃ for 3~4h, centrifuged, washed, and dried to obtain aminated glass fiber.
9. The preparation process of a high-strength modified polypropylene composite material as described in claim 8, characterized in that, The pre-modified glass fiber is prepared by mixing glass fiber, anhydrous ethanol, and deionized water in a mass ratio of 1:(40~50):(10~14), sonicating for 1~2 hours, adding 1.2~1.6 times the mass of the glass fiber of 3-chloropropyltriethoxysilane, stirring and reacting at 60~70℃ for 4~6 hours, centrifuging, washing, and drying to obtain the pre-modified glass fiber.
10. The preparation process of a high-strength modified polypropylene composite material as described in claim 6, characterized in that, The process conditions for melting and plasticizing in step (4) are: 200~210℃, stirring at 40~100r / min for 6~8min; the process conditions for hot pressing are: 190~196℃, hot pressing at 9~11MPa for 5~6min.