High performance flame retardant rubber material and method for making same
By using modified hexachlorocyclotriphosphazene micro-nanotubes and flame-retardant nanocellulose in rubber materials to form a rigid cross-linked network, the flammability problem of rubber materials in high-temperature open flame environments is solved, achieving efficient flame retardancy and improved mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG RUIBA NEW MATERIAL TECH CO LTD
- Filing Date
- 2026-04-20
- Publication Date
- 2026-06-09
AI Technical Summary
Existing rubber materials are flammable in high-temperature and open-flame environments. Traditional flame retardants reduce mechanical properties and pose environmental problems, making it difficult to achieve both excellent flame retardant properties and mechanical strength.
Using natural rubber and styrene-butadiene rubber as the matrix, and combined with modified hexachlorocyclotriphosphazene micro-nanotubes and flame-retardant nanocellulose as bifunctional fillers, the flame retardant and mechanical properties are improved by forming rigid physical crosslinking points and interpenetrating crosslinking networks at the interface.
It achieves a synergistic improvement in the high efficiency of flame retardant properties and mechanical properties of rubber materials, avoiding the performance loss and environmental risks of traditional flame retardants.
Smart Images
Figure CN122167844A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of rubber technology, specifically to a high-performance flame-retardant rubber material and its preparation method. Background Technology
[0002] Rubber, as a polymer material with excellent elasticity, shock absorption, and sealing properties, is widely used in core applications such as sealing of rail transit equipment, insulation of electronic and electrical systems, protection of aerospace pipelines, and fireproofing of buildings. Its service environment often involves high temperatures and open flame risks, leading to increasingly stringent requirements for both flame retardancy and mechanical reliability. Traditional general-purpose rubbers, such as natural rubber, styrene-butadiene rubber, and ethylene propylene diene monomer (EPDM), generally have low oxygen indices and are flammable materials. When burned, they easily produce large amounts of toxic fumes and molten drips, which can easily cause secondary disasters. Among current mainstream flame-retardant modification methods, halogenated flame retardants, while highly efficient, significantly reduce the tensile strength and elongation at break of rubber, and the hydrogen halide gas released during combustion is highly corrosive and physiologically toxic, failing to meet environmental protection and public safety requirements. Halogen-free filled flame-retardant systems, such as aluminum hydroxide and magnesium hydroxide, require high filler content to meet flame-retardant requirements. Therefore, developing a flame-retardant rubber material that combines excellent flame-retardant properties with mechanical strength is of great application value for ensuring the service safety of high-end equipment and promoting the green upgrading of the field of functional rubber materials. Summary of the Invention
[0003] To address the shortcomings of existing technologies, this invention provides a high-performance flame-retardant rubber material and its preparation method. The rubber material prepared by this invention exhibits good flame-retardant properties and mechanical properties.
[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-performance flame-retardant rubber material, comprising the following weight components: 30-40 parts by weight of natural rubber, 65-75 parts by weight of styrene-butadiene rubber, 4-6 parts by weight of modified hexachlorocyclotriphosphazene micro-nanotubes, 9.5-10.5 parts by weight of flame-retardant nanocellulose, 3-7 parts by weight of zinc oxide, 1.8-2.4 parts by weight of stearic acid, 1-2 parts by weight of sulfur, 0.8-1.2 parts by weight of N-cyclohexyl-2-benzothiazole sulfenamide, 0.2-0.7 parts by weight of dibenzothiazole disulfide, 1-1.6 parts by weight of antioxidant RD, 12-18 parts by weight of silica, and 5-9 parts by weight of paraffin oil.
[0005] Preferably, the modified hexachlorocyclotriphosphazene micro / nanotubes are prepared by the following steps: (1) Add 1.6-1.72 g of 1,3-adamantanediamine to 50-60 mL of anhydrous ethanol solvent, stir to dissolve, purge with nitrogen for protection, add 2.8-2.9 g of 6-(hydroxymethyl)pyridinecarboxaldehyde, stir to mix, add 0.4-0.6 mL of acetic acid catalyst, heat to 58-64 °C and react for 3.5-5.5 h. After the reaction is completed, let stand at -5-0 °C to precipitate, wash and vacuum dry to obtain adamantane crosslinked monomer; (2) Add 1-1.1g of hexachlorocyclotriphosphazene and 1.15-1.29g of adamantyl crosslinking monomer to 30-50mL of anhydrous tetrahydrofuran solvent, stir to dissolve, purge with nitrogen for protection, add 0.8-0.9mL of triethylamine acid binder, stir to mix, and obtain a reaction solution. Place the anodic aluminum oxide template horizontally into the reaction solution to completely immerse the template, purge with nitrogen for protection, and let it stand at 25-40℃ for 8-12h. After the reaction is completed, take out the anodic aluminum oxide template, wash it, and soak it in a 4.5%-5.5% sodium hydroxide solution for 5-8h. Centrifuge, wash and vacuum dry to obtain modified hexachlorocyclotriphosphazene micro-nanotubes.
[0006] Preferably, in step (2), the diameter of the anodic aluminum template is 20-30 mm, the pore size is 100-200 nm, and the thickness is 10-30 μm.
[0007] Preferably, the flame-retardant nanocellulose is prepared by the following steps: S1. Add 3.25-3.39 g of paraformaldehyde and 0.2-0.3 g of triethylamine catalyst to 40-60 mL of anhydrous toluene solvent, purge with nitrogen for protection, heat to 68-74℃ and stir for 20-30 min, then add 10.5-10.66 g of p-aminophenyltrimethoxysilane, keep the reaction at this temperature for 1-1.5 h, heat to 80-85℃, and dropwise add a mixed solution of 6.65-6.77 g of 3-allylphenol and 30-40 mL of anhydrous toluene. After the dropwise addition is complete, heat to 100-110℃ and continue the reaction for 3-4 h. After the reaction is complete, wash, remove the solvent by rotary evaporation, and dry under vacuum to obtain the alkenylbenzoxazine intermediate. S2. Add 0.3-0.32 g of boric acid and 3.7-3.73 g of alkenylbenzoxazine intermediate to 30-40 mL of diethylene glycol dimethyl ether solvent, stir to dissolve, purge with nitrogen for protection, add 0.15-0.25 mL of hydrochloric acid solution with pH 1-1.2, react at 125-135℃ for 4-6 h, after the reaction is completed, distill under reduced pressure, wash and filter, dry under vacuum to obtain borosilicate benzoxazine; S3. Add 9.5-10.5g of nanocellulose to 120-180mL of anhydrous ethanol solvent, sonicate for 25-35min, purge with nitrogen, add 2-3g of borosilicate benzoxazine and 0.01-0.015g of azobisisobutyronitrile initiator, stir and mix, heat to 80-90℃ and react for 3-5h. After the reaction is complete, let stand and centrifuge to remove the supernatant, add the lower precipitate to 80-120mL of anhydrous toluene, sonicate for 10-15min, centrifuge, wash and vacuum dry to obtain flame-retardant nanocellulose.
[0008] Preferably, the dropping time of the mixed solution of 3-allylphenol and anhydrous toluene in S1 is 28-32 min.
[0009] Preferably, the preparation method of the high-performance flame-retardant rubber material includes the following steps: natural rubber and styrene-butadiene rubber are added to a two-roll mill and mixed evenly, then plasticized at 45-55℃ for 10-15 min; zinc oxide, stearic acid, and antioxidant RD are added and mixed for 2-4 min; modified hexachlorocyclotriphosphazene micro-nanotubes and flame-retardant nanocellulose are added and mixed for 4-6 min; silica and paraffin oil are added and mixed for 6-10 min; sulfur, N-cyclohexyl-2-benzothiazole sulfenamide, and dibenzothiazole disulfide are added and mixed for 3-5 min; and the mixture is vulcanized for 10-20 min at 150-160℃ and 13-17 MPa using a flat vulcanizing machine to obtain the high-performance flame-retardant rubber material.
[0010] In summary, this application includes at least one of the following beneficial technical effects: This invention uses natural rubber and styrene-butadiene rubber as the matrix, and combines modified hexachlorocyclotriphosphazene micro-nanotubes and flame-retardant nanocellulose as bifunctional fillers to achieve synergistic improvement of flame retardancy and mechanical properties of rubber materials.
[0011] The hollow tubular structure of modified hexachlorocyclotriphosphazene micro-nanotubes can effectively deflect and block the propagation of microcracks that originate inside the rubber, preventing rapid crack penetration and material fracture. The adamantane structure, a highly symmetrical cage-like saturated alicyclic hydrocarbon with extremely high structural rigidity, forms rigid physical cross-linking points at the interface between the filler and the rubber matrix after grafting onto the surface of the modified hexachlorocyclotriphosphazene micro-nanotubes. Under stress, these points can directly bear part of the load while simultaneously preventing microcrack propagation. During rubber combustion, the phosphazene structure decomposes and releases phosphorus-containing free radicals, capturing active free radicals that maintain the chain reaction during combustion and directly interrupting the combustion chain reaction. Simultaneously, the nitrogen elements in the Schiff base structure and pyridine group decompose and release non-flammable inert gases such as nitrogen and ammonia, diluting the concentration of oxygen and combustible decomposition products in the gas phase and inhibiting flame propagation. This method improves the flame retardant properties of rubber materials. Ordinary unmodified nanocellulose has poor interfacial bonding with the rubber matrix, easily leading to agglomeration, interfacial voids, and stress concentration. However, the borosilicate-based benzoxazine with a benzene ring structure grafted onto the surface of this flame-retardant nanocellulose can form a strong π-π interaction with the styrene segments in styrene-butadiene rubber, improving the dispersibility of the nanocellulose filler in the rubber matrix. This enhances the interfacial bonding between the filler and the matrix, allowing external forces to be transferred from the rubber matrix to the high-strength nanocellulose, fully utilizing the nano-reinforcing effect. During rubber vulcanization, the benzoxazine undergoes ring-opening and curing, forming an interpenetrating cross-linked network at the filler-rubber matrix interface, improving the mechanical properties of the rubber material. Furthermore, borosilicate can co-form a highly dense borosilicate glass phase during rubber combustion, further enhancing the flame retardant properties. Attached Figure Description
[0012] Figure 1 It is the synthesis reaction formula for modified hexachlorocyclotriphosphazene micro / nanotubes.
[0013] Figure 2 It is the synthetic reaction formula of borosilicate benzoxazine. Detailed Implementation
[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0015] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.
[0016] Example 1
[0017] (1) Add 1.6 g of 1,3-adamantanediamine to 50 mL of anhydrous ethanol solvent, stir to dissolve, purge with nitrogen for protection, add 2.8 g of 6-(hydroxymethyl)pyridinecarboxaldehyde, stir to mix, add 0.4 mL of acetic acid catalyst, heat to 58 °C and react for 3.5 h. After the reaction is completed, let stand at -5 °C to precipitate, wash and vacuum dry to obtain adamantane crosslinked monomer; (2) Add 1g of hexachlorocyclotriphosphazene and 1.15g of adamantyl crosslinking monomer to 30mL of anhydrous tetrahydrofuran solvent, stir to dissolve, and purge with nitrogen for protection. Add 0.8mL of triethylamine acid binder and stir to mix to obtain a reaction solution. Place the anodic aluminum oxide template horizontally into the reaction solution to completely immerse the template. The anodic aluminum oxide template has a diameter of 20mm, a pore size of 100nm, and a thickness of 10μm. Purge with nitrogen for protection and let it stand at 25℃ for 8h. After the reaction is complete, remove the anodic aluminum oxide template, wash it, and soak it in a 4.5% sodium hydroxide solution for 5h. Centrifuge, wash, and vacuum dry to obtain modified hexachlorocyclotriphosphazene micro-nanotubes. The synthesis reaction formula is as follows: Figure 1 As shown; (3) Add 3.25 g of paraformaldehyde and 0.2 g of triethylamine catalyst to 40 mL of anhydrous toluene solvent, purge with nitrogen for protection, heat to 68 °C and stir for 20 min, then add 10.5 g of p-aminophenyltrimethoxysilane, keep the reaction at the temperature for 1 h, heat to 80 °C, and add dropwise a mixed solution of 6.65 g of 3-allylphenol and 30 mL of anhydrous toluene over a period of 28 min. After the addition is complete, heat to 100 °C and continue the reaction for 3 h. After the reaction is complete, wash, remove the solvent by rotary evaporation, and dry under vacuum to obtain alkenylbenzoxazine intermediate; (4) Add 0.3 g of boric acid and 3.7 g of alkenylbenzoxazine intermediate to 30 mL of diethylene glycol dimethyl ether solvent, stir to dissolve, purge with nitrogen for protection, add 0.15 mL of hydrochloric acid solution with pH 1, react at 125 °C for 4 h, after the reaction is complete, distill under reduced pressure, wash and filter, dry under vacuum to obtain borosilicate benzoxazine; the synthesis reaction formula is as follows Figure 2 As shown; (5) Add 9.5g of nanocellulose to 120mL of anhydrous ethanol solvent, sonicate for 25min, purge with nitrogen for protection, add 2g of borosilicate benzoxazine and 0.01g of azobisisobutyronitrile initiator, stir and mix, heat to 80℃ and react for 3h. After the reaction is completed, let stand and centrifuge to remove the supernatant, add the lower precipitate to 80mL of anhydrous toluene, sonicate for 10min and centrifuge, wash and vacuum dry to obtain flame retardant nanocellulose; (6) Add 30 parts by weight of natural rubber and 65 parts by weight of styrene-butadiene rubber to a two-roll mill and mix evenly. Then, plasticize at 45°C for 10 min. Add 3 parts by weight of zinc oxide, 1.8 parts by weight of stearic acid and 1 part by weight of antioxidant RD and mix for 2 min. Then, add 4 parts by weight of modified hexachlorocyclotriphosphazene micro-nanotubes and 9.5 parts by weight of flame-retardant nanocellulose and mix for 4 min. Add 12 parts by weight of silica and 5 parts by weight of paraffin oil and mix for 6 min. Add 1 part by weight of sulfur, 0.8 parts by weight of N-cyclohexyl-2-benzothiazole sulfenamide and 0.2 parts by weight of dibenzothiazole disulfide and mix for 3 min. Use a flat vulcanizing machine to vulcanize at 150°C and 13 MPa for 10 min to obtain a high-performance flame-retardant rubber material.
[0018] Example 2
[0019] (1) Add 1.72 g of 1,3-adamantanediamine to 60 mL of anhydrous ethanol solvent, stir to dissolve, purge with nitrogen for protection, add 2.9 g of 6-(hydroxymethyl)pyridinecarboxaldehyde, stir to mix, add 0.6 mL of acetic acid catalyst, heat to 64 °C and react for 5.5 h. After the reaction is completed, let stand at 0 °C to precipitate, wash and vacuum dry to obtain adamantane crosslinked monomer; (2) Add 1.1 g of hexachlorocyclotriphosphazene and 1.29 g of adamantyl crosslinking monomer to 50 mL of anhydrous tetrahydrofuran solvent, stir to dissolve, and purge with nitrogen for protection. Add 0.9 mL of triethylamine acid binder and stir to mix to obtain a reaction solution. Place the anodic aluminum oxide template horizontally into the reaction solution to completely immerse the template. The anodic aluminum oxide template has a diameter of 30 mm, a pore size of 200 nm, and a thickness of 30 μm. Purge with nitrogen for protection and let it stand at 40 °C for 12 h. After the reaction is complete, remove the anodic aluminum oxide template, wash it, and soak it in a 5.5% sodium hydroxide solution for 8 h. Centrifuge, wash, and vacuum dry to obtain modified hexachlorocyclotriphosphazene micro-nanotubes. The synthesis reaction formula is as follows: Figure 1 As shown; (3) Add 3.39 g of paraformaldehyde and 0.3 g of triethylamine catalyst to 60 mL of anhydrous toluene solvent, purge with nitrogen for protection, heat to 74 °C and stir for 30 min, then add 10.66 g of p-aminophenyltrimethoxysilane, keep the reaction at the temperature for 1.5 h, heat to 85 °C, and add dropwise a mixed solution of 6.77 g of 3-allylphenol and 40 mL of anhydrous toluene over a period of 32 min. After the addition is complete, heat to 110 °C and continue the reaction for 4 h. After the reaction is complete, wash, remove the solvent by rotary evaporation, and dry under vacuum to obtain alkenylbenzoxazine intermediate; (4) Add 0.32 g of boric acid and 3.73 g of alkenylbenzoxazine intermediate to 40 mL of diethylene glycol dimethyl ether solvent, stir to dissolve, purge with nitrogen for protection, add 0.25 mL of hydrochloric acid solution with pH 1.2, react at 135 °C for 6 h, after the reaction is completed, distill under reduced pressure, wash and filter, dry under vacuum to obtain borosilicate benzoxazine; the synthesis reaction formula is as follows Figure 2 As shown; (5) Add 10.5g of nanocellulose to 180mL of anhydrous ethanol solvent, sonicate for 35min, purge with nitrogen for protection, add 3g of borosilicate benzoxazine and 0.015g of azobisisobutyronitrile initiator, stir and mix, heat to 90℃ and react for 5h. After the reaction is completed, let stand and centrifuge to remove the supernatant, add the lower precipitate to 120mL of anhydrous toluene, sonicate for 15min and centrifuge, wash and vacuum dry to obtain flame retardant nanocellulose; (6) Add 40 parts by weight of natural rubber and 75 parts by weight of styrene-butadiene rubber to a two-roll mill and mix evenly. Then, plasticize at 55°C for 15 min. Add 7 parts by weight of zinc oxide, 2.4 parts by weight of stearic acid and 1.6 parts by weight of antioxidant RD and mix for 4 min. Then, add 6 parts by weight of modified hexachlorocyclotriphosphazene micro-nanotubes and 10.5 parts by weight of flame-retardant nanocellulose and mix for 6 min. Add 18 parts by weight of silica and 9 parts by weight of paraffin oil and mix for 10 min. Add 2 parts by weight of sulfur, 1.2 parts by weight of N-cyclohexyl-2-benzothiazole sulfenamide and 0.7 parts by weight of dibenzothiazole disulfide and mix for 5 min. Use a flat vulcanizing machine to vulcanize at 160°C and 17 MPa for 20 min to obtain a high-performance flame-retardant rubber material.
[0020] Example 3
[0021] (1) Add 1.66 g of 1,3-adamantanediamine to 55 mL of anhydrous ethanol solvent, stir to dissolve, purge with nitrogen for protection, add 2.85 g of 6-(hydroxymethyl)pyridinecarboxaldehyde, stir to mix, add 0.5 mL of acetic acid catalyst, heat to 61 °C and react for 4.5 h. After the reaction is completed, let stand at -2 °C to precipitate, wash and vacuum dry to obtain adamantane crosslinked monomer; (2) Add 1.05 g of hexachlorocyclotriphosphazene and 1.22 g of adamantyl crosslinking monomer to 40 mL of anhydrous tetrahydrofuran solvent, stir to dissolve, and purge with nitrogen for protection. Add 0.85 mL of triethylamine acid binder and stir to mix to obtain a reaction solution. Place the anodic aluminum oxide template horizontally into the reaction solution to completely immerse the template. The anodic aluminum oxide template has a diameter of 25 mm, a pore size of 150 nm, and a thickness of 20 μm. Purge with nitrogen for protection and let it stand at 32 °C for 10 h. After the reaction is complete, remove the anodic aluminum oxide template, wash it, and soak it in a 5% sodium hydroxide solution for 6.5 h. Centrifuge, wash, and vacuum dry to obtain modified hexachlorocyclotriphosphazene micro-nanotubes. The synthesis reaction formula is as follows: Figure 1 As shown; (3) Add 3.32 g of paraformaldehyde and 0.25 g of triethylamine catalyst to 50 mL of anhydrous toluene solvent, purge with nitrogen for protection, heat to 71 °C and stir for 25 min, then add 10.58 g of p-aminophenyltrimethoxysilane, keep the reaction at the temperature for 1.2 h, heat to 82 °C, and add dropwise a mixed solution of 6.71 g of 3-allylphenol and 35 mL of anhydrous toluene over a period of 30 min. After the addition is complete, heat to 105 °C and continue the reaction for 3.5 h. After the reaction is complete, wash, remove the solvent by rotary evaporation, and dry under vacuum to obtain alkenylbenzoxazine intermediate; (4) Add 0.31 g of boric acid and 3.715 g of alkenylbenzoxazine intermediate to 35 mL of diethylene glycol dimethyl ether solvent, stir to dissolve, purge with nitrogen for protection, add 0.2 mL of hydrochloric acid solution with pH 1.1, react at 130 °C for 5 h, after the reaction is complete, distill under reduced pressure, wash and filter, dry under vacuum to obtain borosilicate benzoxazine; the synthesis reaction formula is as follows Figure 2 As shown; (5) Add 10g of nanocellulose to 150mL of anhydrous ethanol solvent, sonicate for 30min, purge with nitrogen for protection, add 2.5g of borosilicate benzoxazine and 0.012g of azobisisobutyronitrile initiator, stir and mix, heat to 85℃ and react for 4h. After the reaction is completed, let stand and centrifuge to remove the supernatant, add the lower precipitate to 100mL of anhydrous toluene, sonicate for 12min and centrifuge, wash and vacuum dry to obtain flame retardant nanocellulose; (6) Add 35 parts by weight of natural rubber and 70 parts by weight of styrene-butadiene rubber to a two-roll mill and mix evenly. Then, plasticize at 50°C for 12 min. Add 5 parts by weight of zinc oxide, 2.1 parts by weight of stearic acid and 1.3 parts by weight of antioxidant RD and mix for 3 min. Then, add 5 parts by weight of modified hexachlorocyclotriphosphazene micro-nanotubes and 10 parts by weight of flame-retardant nanocellulose and mix for 5 min. Add 15 parts by weight of silica and 7 parts by weight of paraffin oil and mix for 8 min. Add 1.5 parts by weight of sulfur, 1 part by weight of N-cyclohexyl-2-benzothiazole sulfenamide and 0.45 parts by weight of dibenzothiazole disulfide and mix for 4 min. Use a flat vulcanizing machine to vulcanize at 155°C and 15 MPa for 15 min to obtain a high-performance flame-retardant rubber material.
[0022] Example 4
[0023] (1) Add 1.6 g of 1,3-adamantanediamine to 50 mL of anhydrous ethanol solvent, stir to dissolve, purge with nitrogen for protection, add 2.8 g of 6-(hydroxymethyl)pyridinecarboxaldehyde, stir to mix, add 0.4 mL of acetic acid catalyst, heat to 58 °C and react for 3.5 h. After the reaction is completed, let stand at -5 °C to precipitate, wash and vacuum dry to obtain adamantane crosslinked monomer; (2) Add 1g of hexachlorocyclotriphosphazene and 1.15g of adamantyl crosslinking monomer to 30mL of anhydrous tetrahydrofuran solvent, stir to dissolve, and purge with nitrogen for protection. Add 0.8mL of triethylamine acid binder and stir to mix to obtain a reaction solution. Place the anodic aluminum oxide template horizontally into the reaction solution to completely immerse the template. The anodic aluminum oxide template has a diameter of 20mm, a pore size of 100nm, and a thickness of 10μm. Purge with nitrogen for protection and let it stand at 25℃ for 8h. After the reaction is complete, remove the anodic aluminum oxide template, wash it, and soak it in a 4.5% sodium hydroxide solution for 5h. Centrifuge, wash, and vacuum dry to obtain modified hexachlorocyclotriphosphazene micro-nanotubes. The synthesis reaction formula is as follows: Figure 1 As shown; (3) Add 3.39 g of paraformaldehyde and 0.3 g of triethylamine catalyst to 60 mL of anhydrous toluene solvent, purge with nitrogen for protection, heat to 74 °C and stir for 30 min, then add 10.66 g of p-aminophenyltrimethoxysilane, keep the reaction at the temperature for 1.5 h, heat to 85 °C, and add dropwise a mixed solution of 6.77 g of 3-allylphenol and 40 mL of anhydrous toluene over a period of 32 min. After the addition is complete, heat to 110 °C and continue the reaction for 4 h. After the reaction is complete, wash, remove the solvent by rotary evaporation, and dry under vacuum to obtain alkenylbenzoxazine intermediate; (4) Add 0.32 g of boric acid and 3.73 g of alkenylbenzoxazine intermediate to 40 mL of diethylene glycol dimethyl ether solvent, stir to dissolve, purge with nitrogen for protection, add 0.25 mL of hydrochloric acid solution with pH 1.2, react at 135 °C for 6 h, after the reaction is completed, distill under reduced pressure, wash and filter, dry under vacuum to obtain borosilicate benzoxazine; the synthesis reaction formula is as follows Figure 2 As shown; (5) Add 10g of nanocellulose to 150mL of anhydrous ethanol solvent, sonicate for 30min, purge with nitrogen for protection, add 2.5g of borosilicate benzoxazine and 0.012g of azobisisobutyronitrile initiator, stir and mix, heat to 85℃ and react for 4h. After the reaction is completed, let stand and centrifuge to remove the supernatant, add the lower precipitate to 100mL of anhydrous toluene, sonicate for 12min and centrifuge, wash and vacuum dry to obtain flame retardant nanocellulose; (6) Add 35 parts by weight of natural rubber and 70 parts by weight of styrene-butadiene rubber to a two-roll mill and mix evenly. Then, plasticize at 50°C for 12 min. Add 5 parts by weight of zinc oxide, 2.1 parts by weight of stearic acid and 1.3 parts by weight of antioxidant RD and mix for 3 min. Then, add 5 parts by weight of modified hexachlorocyclotriphosphazene micro-nanotubes and 10 parts by weight of flame-retardant nanocellulose and mix for 5 min. Add 15 parts by weight of silica and 7 parts by weight of paraffin oil and mix for 8 min. Add 1.5 parts by weight of sulfur, 1 part by weight of N-cyclohexyl-2-benzothiazole sulfenamide and 0.45 parts by weight of dibenzothiazole disulfide and mix for 4 min. Use a flat vulcanizing machine to vulcanize at 155°C and 15 MPa for 15 min to obtain a high-performance flame-retardant rubber material.
[0024] Example 5
[0025] (1) Add 1.66 g of 1,3-adamantanediamine to 55 mL of anhydrous ethanol solvent, stir to dissolve, purge with nitrogen for protection, add 2.85 g of 6-(hydroxymethyl)pyridinecarboxaldehyde, stir to mix, add 0.5 mL of acetic acid catalyst, heat to 61 °C and react for 4.5 h. After the reaction is completed, let stand at -2 °C to precipitate, wash and vacuum dry to obtain adamantane crosslinked monomer; (2) Add 1.05 g of hexachlorocyclotriphosphazene and 1.22 g of adamantyl crosslinking monomer to 40 mL of anhydrous tetrahydrofuran solvent, stir to dissolve, and purge with nitrogen for protection. Add 0.85 mL of triethylamine acid binder and stir to mix to obtain a reaction solution. Place the anodic aluminum oxide template horizontally into the reaction solution to completely immerse the template. The anodic aluminum oxide template has a diameter of 25 mm, a pore size of 150 nm, and a thickness of 20 μm. Purge with nitrogen for protection and let it stand at 32 °C for 10 h. After the reaction is complete, remove the anodic aluminum oxide template, wash it, and soak it in a 5% sodium hydroxide solution for 6.5 h. Centrifuge, wash, and vacuum dry to obtain modified hexachlorocyclotriphosphazene micro-nanotubes. The synthesis reaction formula is as follows: Figure 1 As shown; (3) Add 3.25 g of paraformaldehyde and 0.2 g of triethylamine catalyst to 40 mL of anhydrous toluene solvent, purge with nitrogen for protection, heat to 68 °C and stir for 20 min, then add 10.5 g of p-aminophenyltrimethoxysilane, keep the reaction at the temperature for 1 h, heat to 80 °C, and add dropwise a mixed solution of 6.65 g of 3-allylphenol and 30 mL of anhydrous toluene over a period of 28 min. After the addition is complete, heat to 100 °C and continue the reaction for 3 h. After the reaction is complete, wash, remove the solvent by rotary evaporation, and dry under vacuum to obtain alkenylbenzoxazine intermediate; (4) Add 0.3 g of boric acid and 3.7 g of alkenylbenzoxazine intermediate to 30 mL of diethylene glycol dimethyl ether solvent, stir to dissolve, purge with nitrogen for protection, add 0.15 mL of hydrochloric acid solution with pH 1, react at 125 °C for 4 h, after the reaction is complete, distill under reduced pressure, wash and filter, dry under vacuum to obtain borosilicate benzoxazine; the synthesis reaction formula is as follows Figure 2 As shown; (5) Add 10.5g of nanocellulose to 180mL of anhydrous ethanol solvent, sonicate for 35min, purge with nitrogen for protection, add 3g of borosilicate benzoxazine and 0.015g of azobisisobutyronitrile initiator, stir and mix, heat to 90℃ and react for 5h. After the reaction is completed, let stand and centrifuge to remove the supernatant, add the lower precipitate to 120mL of anhydrous toluene, sonicate for 15min and centrifuge, wash and vacuum dry to obtain flame retardant nanocellulose; (6) Add 40 parts by weight of natural rubber and 75 parts by weight of styrene-butadiene rubber to a two-roll mill and mix evenly. Then, plasticize at 55°C for 15 min. Add 7 parts by weight of zinc oxide, 2.4 parts by weight of stearic acid and 1.6 parts by weight of antioxidant RD and mix for 4 min. Then, add 6 parts by weight of modified hexachlorocyclotriphosphazene micro-nanotubes and 10.5 parts by weight of flame-retardant nanocellulose and mix for 6 min. Add 18 parts by weight of silica and 9 parts by weight of paraffin oil and mix for 10 min. Add 2 parts by weight of sulfur, 1.2 parts by weight of N-cyclohexyl-2-benzothiazole sulfenamide and 0.7 parts by weight of dibenzothiazole disulfide and mix for 5 min. Use a flat vulcanizing machine to vulcanize at 160°C and 17 MPa for 20 min to obtain a high-performance flame-retardant rubber material.
[0026] Comparative Example 1 The difference between this comparative example and Example 5 is that it does not include steps (1) and (2), and does not include modified hexachlorocyclotriphosphazene micro-nanotubes in step (6).
[0027] Comparative Example 2 The difference between this comparative example and Example 5 is that it does not include steps (3), (4), and (5), and in step (6) it uses nanocellulose instead of flame-retardant nanocellulose.
[0028] The limiting oxygen index of the rubber materials in Examples 1-5 and Comparative Examples 1-2 was tested according to GB / T10707-2008. The test results are shown in Table 1.
[0029] Table 1: Flame retardant performance test.
[0030]
[0031] As shown in Table 1, the rubber materials in Examples 1-5 of the present invention have better flame retardant properties compared with the rubber materials in Comparative Examples 1-2.
[0032] The tensile strength and elongation at break of the rubber materials in Examples 1-5 and Comparative Examples 1-2 were tested according to GB / T528-2009; the tear strength of the rubber materials in Examples 1-5 and Comparative Examples 1-2 was tested according to GB / T529-2008. The test results are shown in Table 2.
[0033] Table 2: Mechanical property tests.
[0034]
[0035] As shown in Table 2, the rubber materials in Examples 1-5 of the present invention have better mechanical properties than the rubber materials in Comparative Examples 1-2.
[0036] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0037] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
[0038] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments. It should be noted that many modifications and improvements can be made by those skilled in the art, and all modifications or improvements not exceeding the scope of the claims should be considered within the protection scope of the present invention.
Claims
1. A high-performance flame-retardant rubber material, characterized in that, It comprises the following components by weight: 30-40 parts by weight of natural rubber, 65-75 parts by weight of styrene-butadiene rubber, 4-6 parts by weight of modified hexachlorocyclotriphosphazene micro / nanotubes, 9.5-10.5 parts by weight of flame-retardant nanocellulose, 3-7 parts by weight of zinc oxide, 1.8-2.4 parts by weight of stearic acid, 1-2 parts by weight of sulfur, 0.8-1.2 parts by weight of N-cyclohexyl-2-benzothiazole sulfenamide, 0.2-0.7 parts by weight of dibenzothiazole disulfide, 1-1.6 parts by weight of antioxidant RD, 12-18 parts by weight of silica, and 5-9 parts by weight of paraffin oil.
2. The high-performance flame-retardant rubber material according to claim 1, characterized in that, The modified hexachlorocyclotriphosphazene micro / nanotubes are prepared through the following steps: (1) Add 1.6-1.72 g of 1,3-adamantanediamine to 50-60 mL of anhydrous ethanol solvent, stir to dissolve, purge with nitrogen for protection, add 2.8-2.9 g of 6-(hydroxymethyl)pyridinecarboxaldehyde, stir to mix, add 0.4-0.6 mL of acetic acid catalyst, heat to 58-64 °C and react for 3.5-5.5 h. After the reaction is completed, let stand at -5-0 °C to precipitate, wash and vacuum dry to obtain adamantane crosslinked monomer; (2) Add 1-1.1g of hexachlorocyclotriphosphazene and 1.15-1.29g of adamantyl crosslinking monomer to 30-50mL of anhydrous tetrahydrofuran solvent, stir to dissolve, purge with nitrogen for protection, add 0.8-0.9mL of triethylamine acid binder, stir to mix, and obtain a reaction solution. Place the anodic aluminum oxide template horizontally into the reaction solution to completely immerse the template, purge with nitrogen for protection, and let it stand at 25-40℃ for 8-12h. After the reaction is completed, take out the anodic aluminum oxide template, wash it, and soak it in a 4.5%-5.5% sodium hydroxide solution for 5-8h. Centrifuge, wash and vacuum dry to obtain modified hexachlorocyclotriphosphazene micro-nanotubes.
3. The high-performance flame-retardant rubber material according to claim 2, characterized in that, In step (2), the diameter of the anodic aluminum template is 20-30 mm, the pore size is 100-200 nm, and the thickness is 10-30 μm.
4. The high-performance flame-retardant rubber material according to claim 1, characterized in that, The flame-retardant nanocellulose is prepared by the following steps: S1. Add 3.25-3.39 g of paraformaldehyde and 0.2-0.3 g of triethylamine catalyst to 40-60 mL of anhydrous toluene solvent, purge with nitrogen for protection, heat to 68-74℃ and stir for 20-30 min, then add 10.5-10.66 g of p-aminophenyltrimethoxysilane, keep the reaction at this temperature for 1-1.5 h, heat to 80-85℃, and dropwise add a mixed solution of 6.65-6.77 g of 3-allylphenol and 30-40 mL of anhydrous toluene. After the dropwise addition is complete, heat to 100-110℃ and continue the reaction for 3-4 h. After the reaction is complete, wash, remove the solvent by rotary evaporation, and dry under vacuum to obtain the alkenylbenzoxazine intermediate. S2. Add 0.3-0.32 g of boric acid and 3.7-3.73 g of alkenylbenzoxazine intermediate to 30-40 mL of diethylene glycol dimethyl ether solvent, stir to dissolve, purge with nitrogen for protection, add 0.15-0.25 mL of hydrochloric acid solution with pH 1-1.2, react at 125-135℃ for 4-6 h, after the reaction is completed, distill under reduced pressure, wash and filter, dry under vacuum to obtain borosilicate benzoxazine; S3. Add 9.5-10.5g of nanocellulose to 120-180mL of anhydrous ethanol solvent, sonicate for 25-35min, purge with nitrogen, add 2-3g of borosilicate benzoxazine and 0.01-0.015g of azobisisobutyronitrile initiator, stir and mix, heat to 80-90℃ and react for 3-5h. After the reaction is complete, let stand and centrifuge to remove the supernatant, add the lower precipitate to 80-120mL of anhydrous toluene, sonicate for 10-15min, centrifuge, wash and vacuum dry to obtain flame-retardant nanocellulose.
5. The high-performance flame-retardant rubber material according to claim 4, characterized in that, The addition time of the mixed solution of 3-allylphenol and anhydrous toluene in S1 is 28-32 min.
6. A method for preparing the high-performance flame-retardant rubber material as described in any one of claims 1-5, characterized in that, The process includes the following steps: natural rubber and styrene-butadiene rubber are added to a two-roll mill and mixed evenly. The mixture is then plasticized at 45-55℃ for 10-15 minutes. Zinc oxide, stearic acid, and antioxidant RD are added and mixed for 2-4 minutes. Modified hexachlorocyclotriphosphazene micro-nanotubes and flame-retardant nanocellulose are added and mixed for 4-6 minutes. Silica and paraffin oil are added and mixed for 6-10 minutes. Sulfur, N-cyclohexyl-2-benzothiazole sulfenamide, and dibenzothiazole disulfide are added and mixed for 3-5 minutes. Finally, a flat vulcanizing machine is used to vulcanize the material at 150-160℃ and 13-17MPa for 10-20 minutes to obtain a high-performance flame-retardant rubber material.