Nano-filling reinforced efficient flame-retardant polypropylene material and preparation method thereof

Abstract

The invention discloses a nano-filling reinforced efficient flame-retardant polypropylene material and a preparation method thereof, and relates to the technical field of polypropylene materials. The material is prepared from the following components in parts by weight: 100 parts of polypropylene, 20 to 30 parts of flame-retardant silica sol, 0.5 to 1 part of dicumyl peroxide, 10 to 15 parts of modified zinc oxide whisker, 50 to 60 parts of master batch A, 10 to 20 parts of maleic anhydride grafted polypropylene, 10 to 15 parts of nano filler and 1 to 5 parts of vinyl trimethoxy silane. According to the flame-retardant silica sol, forsterite acidolysis is cooperated with boric acid / phytic acid modification, B / P element doping is achieved, double bonds are grafted through silane hydrolysate, and the interfacial compatible flame retardant is formed. The polypropylene composite material prepared by the invention has excellent mechanical properties, flame retardance and impact resistance, and meanwhile, the content of volatile organic compounds and aldehyde ketone substances is low, so that the requirement of environmental protection is met.

Description

Technical Field

[0001] This invention relates to the field of polypropylene materials technology, specifically to a nano-filled reinforced high-efficiency flame-retardant polypropylene material and its preparation method. Background Technology

[0002] Polypropylene (PP) is widely used in automotive parts, electronics, and building materials due to its excellent processing properties, chemical stability, and low cost. However, polypropylene has a limiting oxygen index (LOI) of only 17-18%, classifying it as a flammable material. Furthermore, it exhibits severe dripping during combustion, posing a significant fire hazard. With increasing market demands for comprehensive material performance, the development of polypropylene composite materials that combine high flame retardancy, excellent mechanical properties, and environmental friendliness has become an urgent industry need.

[0003] Traditional halogenated flame retardants (such as decabromodiphenyl ether) have high flame retardant efficiency, but they release toxic gases such as dioxins during combustion and have been gradually phased out. Halogen-free flame retardants (such as aluminum hydroxide and expanded graphite) require high addition levels (>30wt%) to achieve a V-0 rating, which severely degrades the tensile strength (<35MPa) and impact toughness (<10KJ / m) of the material. 2 Bio-based flame retardants (such as phytic acid and chitosan) are environmentally friendly but have poor heat resistance and are easily decomposed during high-temperature processing; the release of volatile organic compounds and aldehydes and ketones is difficult to meet the standards of high-end fields such as automotive interiors.

[0004] Nanofillers (such as silica and carbon nanotubes) are prone to agglomeration, leading to stress concentration and reducing material toughness. Insufficient surface modification results in poor interfacial compatibility between nanoparticles and the polypropylene matrix, limiting the strength improvement effect. Existing technologies attempt to improve performance through compounded flame-retardant systems or surface-modified nanoparticles, but the flame retardants lack compatibility with the matrix, are prone to migration and precipitation with long-term use, generally exhibit flexural strength below 60 MPa, and poor scratch resistance. Furthermore, high oxygen index (>30%) and high impact strength (>14 KJ / m²) are also problematic. 2 It's difficult to have both. Summary of the Invention

[0005] The purpose of this invention is to provide a nano-filled reinforced high-efficiency flame-retardant polypropylene material and its preparation method, so as to solve the problems existing in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a nano-filled and reinforced high-efficiency flame-retardant polypropylene material, comprising, by weight, 100 parts polypropylene, 20-30 parts flame-retardant silica sol, 0.5-1 parts dicumyl peroxide, 10-15 parts modified zinc oxide whiskers, 50-60 parts masterbatch A, 10-20 parts maleic anhydride-grafted polypropylene, 10-15 parts nanofiller, and 1-5 parts vinyltrimethoxysilane. The preparation method of the flame-retardant silica sol is as follows: pulverize magnesium olivine to 300 mesh, disperse it in water, stir it with a homogenizer to obtain a dispersion, then add boric acid and phytic acid, stir evenly, stir at 80-90℃ for 1 hour, then add 0.3-0.6 times the mass of the dispersion of silane hydrolysate within 30 minutes, continue stirring for 1 hour after the addition is complete, age for 12-48 hours, and concentrate by atmospheric pressure to obtain a flame-retardant silica sol with a solid content of 50%. The nanofiller is composed of cerium oxide with a particle size of 50-200 nm and zinc borate with a particle size of 100-400 nm in a mass ratio of 1-5:1.

[0007] Furthermore, the masterbatch A is prepared by extrusion of polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer in a mass ratio of 30-45:10-20:5-10.

[0008] Furthermore, the forsterite is waste forsterite powder or commercially available forsterite powder. The main chemical components and contents of forsterite are: MgO content of 38-47 wt%, SiO2 content of 39-44 wt%, and Fe2O3 content of 7-11 wt%.

[0009] Furthermore, the modified zinc oxide whiskers are prepared by modification with a coupling agent.

[0010] Furthermore, the zinc oxide whiskers are four-needle zinc oxide whisker needles with a length of approximately 15-25 μm, a bottom diameter of approximately 1.5-3.5 μm, and a tip diameter of approximately 300-500 nm.

[0011] Furthermore, the mass ratio of the dispersion to boric acid and phytic acid is 1:1-2:0.2-1.

[0012] Furthermore, the silane hydrolysate includes 5-30 g / L vinyltrimethoxysilane, 5-40 g / L ethanol, and the remainder deionized water, and the pH of the silane hydrolysate is adjusted to 3-3.5 with hydrochloric acid.

[0013] Furthermore, the concentration of the boric acid is 5-15 g / L.

[0014] Furthermore, the phytic acid concentration is 5-15 g / L.

[0015] Furthermore, the concentration of the dispersion is 1-10 g / L.

[0016] This invention also provides a method for preparing a nano-filled reinforced high-efficiency flame-retardant polypropylene material, comprising the following preparation steps: By weight, take 100 parts of polypropylene and heat it to a molten state. Add 20-30 parts of flame retardant silica sol, 0.5-1 parts of dicumyl peroxide, and 10-15 parts of modified zinc oxide whiskers. Melt and blend at 30 rpm for 70 minutes. Then add 50-60 parts of masterbatch A, 10-20 parts of maleic anhydride-grafted polypropylene, 10-15 parts of nanofiller, and 1-5 parts of vinyltrimethoxysilane. Extrude and granulate at 180°C to obtain polypropylene material.

[0017] Furthermore, the polypropylene: grade: B8101, density 0.9g / cm³, shrinkage rate 1.3-1.7%, produced by Dongguan Qingchuan Plastics Co., Ltd.

[0018] Furthermore, the polystyrene, GPPS123P, is produced by SECCO.

[0019] Furthermore, the maleic anhydride-grafted polypropylene has a grafting rate of 0.8-1.0% and a melt index of 80-120 g / 10 min.

[0020] Furthermore, the number-average molecular weight of the styrene-butadiene-styrene triblock copolymer ranges from 1,000 to 30,000, and the mass fraction of 1,2-butadiene contained therein is 20-80%.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) In this invention, polystyrene with a high proportion is selected as masterbatch A. By adjusting the ratio of polystyrene to polypropylene masterbatch B, the rigidity and strength of polypropylene material are improved while ensuring the toughness of the polypropylene matrix.

[0022] (2) In this invention, forsterite is selected as the raw material for flame-retardant sol. Forsterite precipitates Mg and Fe atoms in an acidic medium, which then transforms into silica sol. The acidic medium selected in this invention is boric acid and phytic acid. While ensuring that Mg atoms can dissolve, the acidic medium can react with Si-OH in the silica sol structure to modify the sol, achieving B and P element doping. This, in conjunction with silica sol, greatly improves the flame-retardant effect of the sol, thereby giving the polypropylene material excellent flame-retardant properties. Furthermore, vinylsilane is added during the preparation process to introduce double bonds into the silica sol molecular chain. During the melt blending and extrusion stages with polypropylene, it can be chemically bonded to the polypropylene molecular chain, achieving better interfacial compatibility, thus giving the polypropylene material a more stable flame-retardant effect.

[0023] (3) The polypropylene composite material prepared by this invention has good mechanical properties, as well as good flame retardancy and impact resistance. Moreover, the polypropylene composite material has low content of volatile organic compounds and aldehydes and ketones, which can well meet the current increasing environmental protection requirements and conform to the needs of environmental protection and sustainable development.

[0024] (4) Compared with single use, the addition of the compound nano-inorganic filler to the system in this invention has the best effect on improving strength, impact resistance and flame retardant performance. Detailed Implementation

[0025] 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.

[0026] Example 1; (1) The magnesium olivine was crushed to 300 mesh and dispersed in water at a concentration of 1 g / L. The dispersion was obtained by stirring with a homogenizer. Then, boric acid and phytic acid at a concentration of 5 g / L were added. The mass ratio of the dispersion to boric acid and phytic acid was 1:1:0.2. After stirring evenly, the mixture was stirred at 90°C and 100 rpm for 1 h. Then, 0.3 times the mass of the dispersion was added within 30 min. The silane hydrolysate included vinyltrimethoxysilane 30 g / L, ethanol 40 g / L, and deionized water as the remainder. The pH of the silane hydrolysate was adjusted to 3 with hydrochloric acid. After the addition was completed, the mixture was stirred for 1 h and aged for 24 h. The solid content of the flame-retardant silica sol was obtained by atmospheric distillation and concentration. (2) Polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer are blended and extruded at a mass ratio of 30:10:5, with the temperature set at 180-240℃ and the screw speed at 50-60rpm to obtain masterbatch A; (3) Mix 20g of anhydrous ethanol, 3g of deionized water and 2g of vinyltrimethoxysilane, adjust the pH to 2 with hydrochloric acid, and let stand at room temperature for 1h to obtain the modified reagent; disperse 30g of dried zinc oxide whiskers and 20g of anhydrous ethanol in a beaker for 1h, add the modified reagent, stir in a water bath at 70℃ for 60min, then filter and dry to obtain modified zinc oxide whiskers; (4) By weight, take 100 parts of polypropylene and heat it to the molten state. Add 20 parts of flame retardant silica sol, 0.5 parts of dicumyl peroxide, and 10 parts of modified zinc oxide whiskers and melt and mix at 30 rpm for 70 minutes. Then add 50 parts of masterbatch A, 10 parts of maleic anhydride grafted polypropylene, 10 parts of nanofiller, and 1 part of vinyltrimethoxysilane and extrude and granulate to obtain polypropylene material. The nanofiller is composed of cerium oxide with a particle size of 50 nm and zinc borate with a particle size of 100 nm in a mass ratio of 1:1.

[0027] Example 2; (1) The magnesium olivine was crushed to 300 mesh and dispersed in water at a concentration of 1 g / L. The dispersion was obtained by stirring with a homogenizer. Then, boric acid and phytic acid at a concentration of 5 g / L were added. The mass ratio of the dispersion to boric acid and phytic acid was 1:1:0.2. After stirring evenly, the mixture was stirred at 90°C and 100 rpm for 1 h. Then, 0.3 times the mass of the dispersion was added within 30 min. The silane hydrolysate included 30 g / L vinyltrimethoxysilane, 40 g / L ethanol, and the remainder deionized water. The pH of the silane hydrolysate was adjusted to 3 with hydrochloric acid. After the addition was completed, the mixture was stirred for 1 h and aged for 24 h. The solid content of the flame-retardant silica sol was obtained by atmospheric distillation and concentration. (2) Polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer are blended and extruded at a mass ratio of 30:20:5, with the temperature set at 180-240℃ and the screw speed at 50-60rpm to obtain masterbatch A; (3) Mix 20g of anhydrous ethanol, 3g of deionized water and 2g of vinyltrimethoxysilane, adjust the pH value to 2 with hydrochloric acid, and let stand at room temperature for 1h to obtain the modified reagent; disperse 30g of dried zinc oxide whiskers and 20g of anhydrous ethanol in a beaker for 1h, add the modified reagent, stir in a water bath at 70℃ for 60min, then filter and dry to obtain modified zinc oxide whiskers; (4) By weight, take 100 parts of polypropylene and heat it to the molten state. Add 21 parts of flame retardant silica sol, 0.5 parts of dicumyl peroxide, and 10 parts of modified zinc oxide whiskers and melt and mix at 30 rpm for 70 minutes. Then add 51 parts of masterbatch A, 10 parts of maleic anhydride grafted polypropylene, 10.7 parts of nanofiller, and 1 part of vinyltrimethoxysilane and extrude and granulate to obtain polypropylene material. The nanofiller is composed of cerium oxide with a particle size of 50 nm and zinc borate with a particle size of 100 nm in a mass ratio of 1:1.

[0028] Example 3; (1) The magnesium olivine was crushed to 300 mesh and dispersed in water at a concentration of 3.2 g / L. The dispersion was obtained by stirring with a homogenizer. Then, boric acid and phytic acid at a concentration of 7.5 g / L were added. The mass ratio of the dispersion to boric acid and phytic acid was 1:1.5:0.4. After stirring evenly, the mixture was stirred at 90°C and 100 rpm for 1 h. Then, silane hydrolysate with a mass of 0.4 times that of the dispersion was added within 30 min. The silane hydrolysate included vinyltrimethoxysilane 11 g / L, ethanol 40 g / L, and deionized water as the remainder. The pH of the silane hydrolysate was adjusted to 3 with hydrochloric acid. After the addition was completed, the mixture was stirred for 1 h and aged for 24 h. The solid content of the flame-retardant silica sol was obtained by atmospheric distillation and concentration. (2) Polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer are blended and extruded at a mass ratio of 34:10:5.7, with the temperature set at 180-240℃ and the screw speed at 50-60rpm to obtain masterbatch A; (3) Mix 27.5g of anhydrous ethanol, 4.7g of deionized water and 4g of vinyltrimethoxysilane, adjust the pH value to 2 with hydrochloric acid, and let stand at room temperature for 1h to obtain the modified reagent; disperse 35g of dried zinc oxide whiskers and 30g of anhydrous ethanol in a beaker for 1h, add the modified reagent, stir in a water bath at 70℃ for 60min, then filter and dry to obtain modified zinc oxide whiskers; (4) By weight, take 100 parts of polypropylene and heat it to the molten state. Add 22 parts of flame retardant silica sol, 0.5 parts of dicumyl peroxide, and 15 parts of modified zinc oxide whiskers and melt and mix at 30 rpm for 70 minutes. Then add 55 parts of masterbatch A, 12 parts of maleic anhydride grafted polypropylene, 11 parts of nanofiller, and 1 part of vinyltrimethoxysilane and extrude and granulate to obtain polypropylene material. The nanofiller is composed of cerium oxide with a particle size of 60 nm and zinc borate with a particle size of 200 nm in a mass ratio of 2:1.

[0029] Example 4; (1) The magnesium olivine was crushed to 300 mesh and dispersed in water at a concentration of 3.2 g / L. The dispersion was obtained by stirring with a homogenizer. Then, boric acid and phytic acid at a concentration of 7.5 g / L were added. The mass ratio of the dispersion to boric acid and phytic acid was 1:1.5:0.4. After stirring evenly, the mixture was stirred at 90°C and 100 rpm for 1 h. Then, silane hydrolysate with a mass of 0.4 times that of the dispersion was added within 30 min. The silane hydrolysate included vinyltrimethoxysilane 11 g / L, ethanol 40 g / L, and deionized water as the remainder. The pH of the silane hydrolysate was adjusted to 3 with hydrochloric acid. After the addition was completed, the mixture was stirred for 1 h and aged for 24 h. The solid content of the flame-retardant silica sol was obtained by atmospheric distillation and concentration. (2) Polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer are blended and extruded at a mass ratio of 30:10:5, with the temperature set at 180-240℃ and the screw speed at 50-60rpm to obtain masterbatch A; (3) Mix 27.5g of anhydrous ethanol, 4.7g of deionized water and 4g of vinyltrimethoxysilane, adjust the pH value to 2 with hydrochloric acid, and let stand at room temperature for 1h to obtain the modified reagent; disperse 35g of dried zinc oxide whiskers and 30g of anhydrous ethanol in a beaker for 1h, add the modified reagent, stir in a water bath at 70℃ for 60min, then filter and dry to obtain modified zinc oxide whiskers; (4) By weight, take 100 parts of polypropylene and heat it to the molten state. Add 23 parts of flame retardant silica sol, 0.5 parts of dicumyl peroxide, and 12 parts of modified zinc oxide whiskers and melt and mix at 30 rpm for 70 minutes. Then add 50 parts of masterbatch A, 10 parts of maleic anhydride grafted polypropylene, 15 parts of nanofiller, and 3 parts of vinyltrimethoxysilane and extrude and granulate to obtain polypropylene material. The nanofiller is composed of cerium oxide with a particle size of 60 nm and zinc borate with a particle size of 200 nm in a mass ratio of 2:1.

[0030] Example 5; (1) The magnesium olivine was crushed to 300 mesh and dispersed in water at a concentration of 7 g / L. The dispersion was obtained by stirring with a homogenizer. Then, boric acid at a concentration of 11 g / L and phytic acid at a concentration of 5 g / L were added. The mass ratio of the dispersion to boric acid and phytic acid was 1:1.5:0.8. After stirring evenly, the mixture was stirred at 90°C and 100 rpm for 1 h. Then, 0.5 times the mass of the dispersion was added within 30 min. The silane hydrolysate included 21 g / L vinyltrimethoxysilane, 40 g / L ethanol, and the remainder deionized water. The pH of the silane hydrolysate was adjusted to 3.5 with hydrochloric acid. After the addition was completed, the mixture was stirred for 1 h and aged for 24 h. The solid content of the flame-retardant silica sol was obtained by atmospheric distillation and concentration. (2) Polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer are blended and extruded at a mass ratio of 38:15:7.5, with the temperature set at 180-240℃ and the screw speed at 50-60rpm to obtain masterbatch A; (3) Mix 40g of anhydrous ethanol, 7.6g of deionized water and 7.3g of vinyltrimethoxysilane, adjust the pH value to 3 with hydrochloric acid, and let stand at room temperature for 2h to obtain the modified reagent; disperse 43g of dried zinc oxide whiskers and 47g of anhydrous ethanol in a beaker for 2h, add the modified reagent, stir in a water bath at 70℃ for 60min, then filter and dry to obtain modified zinc oxide whiskers; (4) By weight, take 100 parts of polypropylene and heat it to the molten state. Add 26 parts of flame retardant silica sol, 0.8 parts of dicumyl peroxide, and 13 parts of modified zinc oxide whiskers and melt and mix at 30 rpm for 70 minutes. Then add 55 parts of masterbatch A, 15 parts of maleic anhydride grafted polypropylene, 10 parts of nanofiller, and 3 parts of vinyltrimethoxysilane and extrude and granulate to obtain polypropylene material. The nanofiller is composed of cerium oxide with a particle size of 120 nm and zinc borate with a particle size of 300 nm in a mass ratio of 3:1.

[0031] Example 6; (1) The magnesium olivine was crushed to 300 mesh and dispersed in water at a concentration of 7 g / L. The dispersion was obtained by stirring with a homogenizer. Then, boric acid at a concentration of 11 g / L and phytic acid at a concentration of 5 g / L were added. The mass ratio of the dispersion to boric acid and phytic acid was 1:1.5:0.8. After stirring evenly, the mixture was stirred at 90°C and 100 rpm for 1 h. Then, 0.5 times the mass of the dispersion was added within 30 min. The silane hydrolysate included 21 g / L vinyltrimethoxysilane, 40 g / L ethanol, and the remainder deionized water. The pH of the silane hydrolysate was adjusted to 3.5 with hydrochloric acid. After the addition was completed, the mixture was stirred for 1 h and aged for 24 h. The solid content of the flame-retardant silica sol was obtained by atmospheric distillation and concentration. (2) Polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer are blended and extruded at a mass ratio of 40:17:10, with the temperature set at 180-240℃ and the screw speed at 50-60rpm to obtain masterbatch A; (3) Mix 40g of anhydrous ethanol, 7.6g of deionized water and 7.3g of vinyltrimethoxysilane, adjust the pH value to 3 with hydrochloric acid, and let stand at room temperature for 2h to obtain the modified reagent; disperse 43g of dried zinc oxide whiskers and 47g of anhydrous ethanol in a beaker for 2h, add the modified reagent, stir in a water bath at 70℃ for 60min, then filter and dry to obtain modified zinc oxide whiskers; (4) By weight, take 100 parts of polypropylene and heat it to the molten state. Add 30 parts of flame retardant silica sol, 1 part of dicumyl peroxide, and 15 parts of modified zinc oxide whiskers and melt and mix at 30 rpm for 70 minutes. Then add 50 parts of masterbatch A, 20 parts of maleic anhydride grafted polypropylene, 15 parts of nanofiller, and 5 parts of vinyltrimethoxysilane and extrude and granulate to obtain polypropylene material. The nanofiller is composed of cerium oxide with a particle size of 120 nm and zinc borate with a particle size of 300 nm in a mass ratio of 3:1.

[0032] Example 7; (1) Fragmented magnesium olivine was crushed to 300 mesh and dispersed in water at a concentration of 7 g / L. The dispersion was obtained by stirring with a homogenizer. Then, boric acid at a concentration of 11 g / L and phytic acid at a concentration of 10 g / L were added. The mass ratio of the dispersion to boric acid and phytic acid was 1:1.5:0.8. After stirring evenly, the mixture was stirred at 90°C and 100 rpm for 1 h. Then, 0.5 times the mass of the dispersion was added within 30 min. The silane hydrolysate included vinyltrimethoxysilane 21 g / L, ethanol 40 g / L, and deionized water as the remainder. The pH of the silane hydrolysate was adjusted to 3.5 with hydrochloric acid. After the addition was completed, the mixture was stirred for 1 h and aged for 24 h. The solid content of the flame-retardant silica sol was obtained by atmospheric distillation and concentration. (2) Polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer are blended and extruded at a mass ratio of 45:10:10, with the temperature set at 180-240℃ and the screw speed at 50-60rpm to obtain masterbatch A; (3) Mix 40g of anhydrous ethanol, 7.6g of deionized water and 7.3g of vinyltrimethoxysilane, adjust the pH value to 3 with hydrochloric acid, and let stand at room temperature for 2h to obtain the modified reagent; disperse 43g of dried zinc oxide whiskers and 47g of anhydrous ethanol in a beaker for 2h, add the modified reagent, stir in a water bath at 70℃ for 60min, then filter and dry to obtain modified zinc oxide whiskers; (4) By weight, take 100 parts of polypropylene and heat it to the molten state. Add 30 parts of flame retardant silica sol, 1 part of dicumyl peroxide, and 12 parts of modified zinc oxide whiskers and melt and mix at 30 rpm for 70 minutes. Then add 58 parts of masterbatch A, 15 parts of maleic anhydride grafted polypropylene, 15 parts of nanofiller, and 5 parts of vinyltrimethoxysilane and extrude and granulate to obtain polypropylene material. The nanofiller is composed of cerium oxide with a particle size of 120 nm and zinc borate with a particle size of 300 nm in a mass ratio of 3:1.

[0033] Comparative Example 1; The difference between Comparative Example 1 and Example 3 is that boric acid is not added in the preparation of flame-retardant silica sol, the phytic acid concentration is adjusted to 15 g / L, and the remaining steps are the same as in Example 3.

[0034] Comparative Example 2; The difference between Comparative Example 2 and Example 3 is that phytic acid is not added in the preparation of flame-retardant silica sol, the boric acid concentration is adjusted to 15 g / L, and the remaining steps are the same as in Example 3.

[0035] Comparative Example 3; The difference between Comparative Example 3 and Example 3 is that no silane hydrolysate is added in the preparation of the flame-retardant silica sol, while the other steps are the same as in Example 3.

[0036] Comparative Example 4; The difference between Comparative Example 4 and Example 3 is that the flame-retardant silica sol is concentrated to a solid content of 20%, while the other steps are the same as in Example 3.

[0037] Comparative Example 5; The difference between Comparative Example 5 and Example 3 is that Masterbatch A is not added, and the other steps are the same as in Example 3.

[0038] Comparative Example 6; The difference between Comparative Example 6 and Example 3 is that modified zinc oxide whiskers are not added, and the other steps are the same as in Example 3.

[0039] Comparative Example 7; The difference between Comparative Example 7 and Example 3 is that zinc borate is not added, and the remaining steps are the same as in Example 3.

[0040] Comparative Example 8; The difference between Comparative Example 8 and Example 3 is that cerium oxide is not added, and the other steps are the same as in Example 3.

[0041] Performance testing (1) Flame retardant performance: Tested according to the test standards provided by UL-94, with a sample size of 125×13×3.0mm; (2) Tensile strength: Tested according to ISO527-2-2016, with a tensile speed of 50 mm / min; (3) Bending strength: Tested according to the standard provided by ISO 178; (4) Notched impact strength: According to standard ISO180-2000, the test temperature is 23℃; (5) Oxygen index: The test is performed according to GB / T2406.2-2009 Oxygen index method - Test method for burning performance of plastics.

[0042] The polypropylene materials provided in Examples 1-7 and Comparative Examples 1-8 were tested according to the above test methods, and the test results are shown in Table 1:

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A high-efficiency flame-retardant polypropylene material reinforced with nanofiller, characterized in that, By weight, it includes 100 parts polypropylene, 20-30 parts flame retardant silica sol, 0.5-1 part dicumyl peroxide, 10-15 parts modified zinc oxide whiskers, 50-60 parts masterbatch A, 10-20 parts maleic anhydride grafted polypropylene, 10-15 parts nanofiller, and 1-5 parts vinyltrimethoxysilane. The preparation method of the flame-retardant silica sol is as follows: pulverize magnesium olivine to 300 mesh, disperse it in water, stir it with a homogenizer to obtain a dispersion, then add boric acid and phytic acid, stir evenly, stir at 80-90℃ for 1 hour, then add 0.3-0.6 times the mass of the dispersion of silane hydrolysate within 30 minutes, continue stirring for 1 hour after the addition is complete, age for 12-48 hours, and concentrate by atmospheric pressure to obtain a flame-retardant silica sol with a solid content of 50%. The nanofiller is composed of cerium oxide and zinc borate in a mass ratio of 1-5:

1.

2. The high-efficiency flame-retardant polypropylene material with nano-filling reinforcement according to claim 1, characterized in that, The masterbatch A is prepared by extrusion of polystyrene, polypropylene, and styrene-butadiene-styrene triblock copolymer in a mass ratio of 30-45:10-20:5-10.

3. The high-efficiency flame-retardant polypropylene material with nano-filling reinforcement according to claim 1, characterized in that, The cerium oxide particles have a diameter of 50-200 nm, and the zinc borate particles have a diameter of 100-400 nm.

4. The high-efficiency flame-retardant polypropylene material with nano-filling reinforcement according to claim 1, characterized in that, The modified zinc oxide whiskers were prepared by modification with a coupling agent.

5. The high-efficiency flame-retardant polypropylene material with nano-filling reinforcement according to claim 1, characterized in that, The mass ratio of the dispersion to boric acid and phytic acid is 1:1-2:0.2-1.

6. The high-efficiency flame-retardant polypropylene material with nano-filling reinforcement according to claim 1, characterized in that, The silane hydrolysate comprises 5-30 g / L vinyltrimethoxysilane, 5-40 g / L ethanol, and the remainder deionized water, and the pH of the silane hydrolysate is adjusted to 3-3.5 with hydrochloric acid.

7. The high-efficiency flame-retardant polypropylene material with nano-filling reinforcement according to claim 1, characterized in that, The concentration of boric acid is 5-15 g / L.

8. The high-efficiency flame-retardant polypropylene material with nano-filled reinforcement according to claim 1, characterized in that, The phytic acid concentration is 5-15 g / L.

9. The high-efficiency flame-retardant polypropylene material with nano-filling reinforcement according to claim 1, characterized in that, The concentration of the dispersion is 1-10 g / L.

10. A method for preparing a nano-filled and reinforced high-efficiency flame-retardant polypropylene material, characterized in that, The preparation steps include the following: By weight, take 100 parts of polypropylene and heat it to a molten state. Add 20-30 parts of flame retardant silica sol, 0.5-1 parts of dicumyl peroxide, and 10-15 parts of modified zinc oxide whiskers. Melt and blend at 30 rpm for 70 minutes. Then add 50-60 parts of masterbatch A, 10-20 parts of maleic anhydride-grafted polypropylene, 10-15 parts of nanofiller, and 1-5 parts of vinyltrimethoxysilane. Extrude and granulate at 180°C to obtain polypropylene material.

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