Corrosion-resistant flame-retardant fireproof sealant material and preparation method thereof

Abstract

The invention discloses a corrosion-resistant flame-retardant fireproof sealant material and a preparation method thereof, belongs to the technical field of sealant preparation, and aims to solve the technical problem that the organic liquid corrosion resistance and flame retardance of a sealant in the prior art need to be further improved. A phosphazene silicon epoxy flame-retardant phase, a catechol phosphonic acid bonding phase and a boron-nitrogen coordination hole sealing phase are cooperatively introduced into a sealant system, and a continuous and stable multi-phase network structure is constructed through a step-by-step reaction and a curing process, so that the flame-retardant, anti-bonding enhancement and pore regulation effects of the sealant are remarkably improved; according to the present invention, the flame-retardant and fireproof performance requirements are met, the good flexibility and the good structural integrity are provided, and the experimental results show that the mechanical property retention rate of the sealant after the action of the liquid medium is high, and the excellent corrosion resistance and the excellent environmental adaptability are represented.

Description

Technical Field

[0001] This invention relates to the field of sealant preparation technology, specifically to a corrosion-resistant, flame-retardant, and fireproof sealant material and its preparation method. Background Technology

[0002] With the increasing demands for sealing material performance in the construction, transportation, and industrial sectors, flame-retardant and fire-resistant sealants have gradually become a key technology. These sealants not only need to meet the basic requirements of flame retardancy and fire resistance, but also must have good corrosion resistance, maintaining their mechanical properties and structural integrity even after long-term exposure to various chemical media and humid environments. Currently, most common flame-retardant sealants on the market rely on organic polymer matrices combined with different flame-retardant fillers or additives, such as inorganic flame retardants and phosphorus-based flame retardants, to achieve flame-retardant effects. However, these materials often face problems such as insufficient corrosion resistance and accelerated aging when exposed to complex environmental conditions, making it difficult to guarantee their long-term performance.

[0003] While existing flame-retardant and fireproof sealant materials have made some progress in flame-retardant performance, they still have significant shortcomings in corrosion resistance, durability, and structural stability. Most traditional materials rely on single flame-retardant fillers or reinforcing components, which makes them prone to mechanical property degradation and interfacial mismatch in complex environments, especially in organic media or liquid corrosive environments. These defects not only affect the long-term performance of the materials, but also lead to instability during load-bearing and extension processes, making it difficult to meet the multiple performance requirements of corrosion resistance, aging resistance, and flame retardancy in demanding application scenarios.

[0004] Furthermore, in existing processes, flame retardancy and corrosion resistance are usually achieved through simple physical mixing, without deep regulation at the molecular structure level. This approach often results in the failure of the material's molecular structure to form an effective synergistic effect, which in turn affects its performance under thermal action, liquid media, or high-temperature environments. Especially at high temperatures, the thermal stability and combustion evolution path of existing materials are difficult to control effectively, leading to structural damage and a lack of stable thermal response mechanisms, making it impossible to maintain consistent performance in complex applications. Summary of the Invention

[0005] The purpose of this invention is to provide a corrosion-resistant, flame-retardant, and fireproof sealant material and its preparation method, in order to solve the technical problem that the resistance to organic liquid corrosion and flame-retardant properties of sealants in the prior art need to be further improved.

[0006] The objective of this invention can be achieved through the following technical solutions: A corrosion-resistant, flame-retardant, and fireproof sealant material comprises the following raw materials in parts by weight: 40-50 parts of phosphazene-silicon epoxy flame-retardant phase, 30-40 parts of catechol-phosphonic acid adhesive phase, 18-21 parts of boron-nitrogen coordination sealing phase, 6-8 parts of dioctyl phthalate, and 4-6 parts of fumed silica. Furthermore, the preparation method of the phosphazene silicon epoxy flame retardant phase is as follows: A1. Add allylsilane phosphazene intermediate and tetrahydrofuran to a reaction vessel and stir until evenly dispersed. Then add deionized water and glacial acetic acid. Heat the reaction vessel to 40-50℃ and keep it at that temperature for 3-5 hours. After the reaction is completed, reduce the pressure and distill until no liquid is collected to obtain phosphazene silicon oxide flame retardant intermediate. A2. Add the phosphazene silicon oxide flame retardant intermediate and tetrahydrofuran to the reaction vessel and stir until evenly dispersed. Then add the oxidant and 98wt% concentrated sulfuric acid. Control the temperature of the reaction vessel at 50-60℃ and keep it warm and stir for 4-6 hours. The post-treatment yields the phosphazene silicon epoxy flame retardant phase.

[0007] The reaction principle for preparing the phosphazene silicon epoxy flame retardant phase is as follows: The alkoxysilane structure in the allylsilane phosphazene intermediate molecule can undergo hydrolysis under acidic conditions to generate silanol groups, which then form silicon-oxygen bonds through condensation reactions, thereby constructing a silicon-oxygen linkage structure on the phosphazene skeleton to obtain an intermediate containing phosphazene and silicon-oxygen units. The residual allyl carbon-carbon double bond in this structure undergoes an epoxidation reaction under the combined action of strong acid and oxidant, and the double bond is converted into an epoxy group and introduced into the molecular structure. Through the synergistic action of silicon-oxygen condensation reaction and allyl epoxidation reaction, the system simultaneously contains the phosphazene skeleton, silicon-oxygen structure and epoxy functional group, forming a composite structural unit with multiple chemical bond types coexisting.

[0008] Furthermore, in step A1, the ratio of allyl silane phosphazene intermediate, tetrahydrofuran, deionized water and glacial acetic acid is 18-20g:100mL:30-40mL:1-2mL. Furthermore, in step A2, the ratio of phosphazene silicon oxide flame retardant intermediate, tetrahydrofuran, oxidant and 98wt% concentrated sulfuric acid is 15-18g:80mL:18-21mL:0.4-0.6mL, wherein the oxidant is a 30wt% hydrogen peroxide aqueous solution. The post-treatment includes: after the reaction is completed, adjusting the reaction system to neutrality with saturated ammonia water, and then distilling under reduced pressure until no liquid is collected to obtain the phosphazene silicon epoxy flame retardant phase.

[0009] Furthermore, the preparation method of the allylsilane phosphazene intermediate is as follows: hexachlorocyclotriphosphazene and tetrahydrofuran are added to a reaction vessel and stirred until dissolved. After nitrogen protection is introduced and the reaction vessel is cooled to 0-5°C, p-allylphenol, 3-aminopropyltriethoxysilane and triethylamine are added. The mixture is kept at a constant temperature and stirred for 40-60 min, and then the temperature of the reaction vessel is raised to 35-45°C and kept at a constant temperature and stirred for 5-7 h. The allylsilane phosphazene intermediate is obtained by post-processing.

[0010] The reaction principle for preparing allylsilane phosphazene intermediates is as follows: The bond between the phosphorus and chlorine atoms in the hexachlorocyclotriphosphazene molecule is highly reactive and can undergo nucleophilic substitution reactions under alkaline conditions. In particular, the phenolic hydroxyl group in the p-allylphenol molecule generates a phenoxy anion under alkaline conditions, which acts as a nucleophile and undergoes a substitution reaction with the phosphazene skeleton to introduce an aromatic substituent containing an allyl group. The amino group in the 3-aminopropyltriethoxysilane molecule can also participate in nucleophilic substitution, causing the silane structure to bond to the phosphazene ring. Through the synergistic substitution of different nucleophilic groups, a phosphazene structural unit containing both allyl and silane substituents is constructed.

[0011] Furthermore, the ratio of hexachlorocyclotriphosphazene, tetrahydrofuran, p-allylphenol, 3-aminopropyltriethoxysilane, and triethylamine is 9-12g:100mL:6-8g:8-10mL:10mL. The post-treatment includes: filtering to remove salt after the reaction and distilling under reduced pressure until no liquid is collected, to obtain the allylsilanephosphazene intermediate.

[0012] Furthermore, the catechol phosphonic acid binder phase is prepared by the following method: B1. Add catechol and dichloromethane to the reactor and stir until dissolved. Cool the reactor to 0-5°C under nitrogen protection. Add triethylamine and add acryloyl chloride in ten equal batches with an interval of 5-8 minutes between additions. After the addition is complete, heat the reactor to 20-25°C and keep it at this temperature for 3-5 hours. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected. Store in the dark to obtain acrylate catechol monomer. B2. Add acrylate catechol monomer and N,N-dimethylformamide to the reactor and stir. After uniform dispersion, add vinylphosphonic acid and azobisisobutyronitrile. After nitrogen protection, heat the reactor to 60-70℃ and stir for 6-8 hours. Post-treatment yields the catecholphosphonic acid binder phase.

[0013] The reaction principle for preparing the catechol phosphonic acid binder phase is as follows: The adjacent phenolic hydroxyl groups in the catechol molecule have high reactivity. Under alkaline conditions, they can undergo acyl chloride substitution reactions with acyl chloride, introducing polymerizable acrylate groups to form acrylated catechol monomers containing ortho-dihydroxy structures. These monomer molecules simultaneously retain aromatic ring structures and reactive double bonds, providing reaction sites for subsequent reactions. The vinyl groups in the vinyl phosphonic acid molecule can participate in copolymerization reactions under free radical initiation conditions. Their phosphonic acid groups are introduced into the molecular structure during polymerization, so that the system simultaneously contains aromatic phenolic structures, carbon-carbon backbones, and phosphonic acid functional groups, thereby forming a polymeric coordination framework in which catechol and phosphonic acid structures coexist.

[0014] Furthermore, in step B1, the ratio of catechol, dichloromethane, triethylamine and acryloyl chloride is 10-12g:100mL:10-12mL:8-10mL. Further, in step B2, the ratio of the esterified catechol monomer, N,N-dimethylformamide, vinylphosphonic acid and azobisisobutyronitrile is 12-16g:100mL:8-10g:1g. The post-treatment includes: after the reaction is completed, the reaction solution is filtered to collect the filter cake, which is washed three times with deionized water and anhydrous ethanol and then dried to obtain the catechol phosphonic acid binder phase.

[0015] Furthermore, the preparation method of the boron-nitrogen coordination sealing phase is as follows: boric acid, triethanolamine and 1,2-propanediol are added to a reaction vessel and stirred until they are mixed evenly. The reaction vessel is then heated to 110-120°C, followed by the addition of 2-methylimidazole. The temperature is then raised to 120-130°C and the reaction is maintained for 2-4 hours. The boron-nitrogen coordination sealing phase is then obtained after post-treatment.

[0016] The reaction principle for preparing boron-nitrogen coordinated sealing phases is as follows: The boron atom in the boric acid molecule has electronic defect characteristics and can act as a Lewis acid to coordinate with nitrogen-containing ligands. Among them, the amino group and polyhydroxy structure in the triethanolamine molecule can form multi-point coordination relationships with the boron center to construct a stable boron-oxygen-nitrogen coordination structure. 1,2-propanediol interacts with boric acid through coordination or esterification via its hydroxyl groups, which plays a regulatory role in the coordination environment around the boron center. The imidazole nitrogen atom in 2-methylimidazolium further participates in coordination as a Lewis base, resulting in a multi-coordination structure with boron-nitrogen coordination as the core in the system.

[0017] Furthermore, in the preparation of the boron-nitrogen coordination sealing phase, the ratio of boric acid, triethanolamine, 1,2-propanediol and 2-methylimidazole is 8-10g:10-12mL:4-6mL:0.6-0.8g. The post-treatment includes: cooling to below 60°C after the reaction is completed, discharging the material, filtering while hot, and drying to obtain the boron-nitrogen coordination sealing phase.

[0018] This invention also discloses a method for preparing a corrosion-resistant, flame-retardant, and fireproof sealant material, comprising the following steps: adding a phosphazene silicon epoxy flame-retardant phase, a catechol phosphonic acid adhesive phase, and a boron-nitrogen coordination sealing phase into a vacuum stirring vessel; heating the vacuum stirring vessel to 25-35°C and stirring for 20-40 minutes; then adding dioctyl phthalate and continuing to stir for 15-25 minutes; then adding fumed silica and stirring until uniform and free of dry powder agglomerates; and finally performing vacuum degassing to obtain the sealant material.

[0019] The reaction principle for preparing sealant materials is as follows: During the mixing process, the phosphazene silicon epoxy flame retardant phase, the catechol phosphonic acid adhesive phase, and the boron-nitrogen coordination sealing phase undergo multiple interactions with the polar groups in their respective molecular structures as interaction sites. Specifically, the epoxy groups and siloxane bonds in the phosphazene silicon epoxy structure form a stable physical-chemical cross-linking network with the hydroxyl, phosphonic acid, and boron-nitrogen coordination structures in the system through hydrogen bonding, coordination, and intermolecular forces. Dioctyl phthalate, as a small molecule plasticizer, is inserted into the above network structure, regulating the intermolecular interaction distance. Fumed silica, through its high specific surface area, adsorbs and interacts with the polar groups in the system, thereby jointly constructing a continuous structural system in which multiple phase components coexist synergistically.

[0020] The present invention has the following beneficial effects: 1. The phosphazene silicon epoxy flame retardant phase prepared by this invention uses its multifunctional structure as an important component of the continuous phase. Its phosphazene skeleton and silicon oxide structure jointly participate in network construction during the curing process, playing a leading role in the load-bearing and deformation response of the overall structure. Moreover, the catechol phosphonic acid binder phase does not exist as a single reinforcing component, but rather, through its flexible chain segments and polar groups, it is embedded between the phosphazene silicon epoxy structures during the curing network formation process, thereby regulating the movement of local chain segments and enabling the system to undergo coordinated deformation during the stress process. At the same time, the boron-nitrogen coordination sealing phase exists in a dispersed state in the system. Its multi-point coordination structure helps to stabilize the multiphase interface and reduce stress concentration caused by interface mismatch under external force. The mutual interlocking of the above three materials at the structural level makes the material exhibit continuous and stable response characteristics during the load-bearing and extension process.

[0021] 2. In an organic medium environment, the catechol phosphonic acid binder phase first participates in the construction of the internal network through its multifunctional groups, forming a relatively stable intermolecular interaction system within the material. This structure constrains the diffusion behavior of water molecules during operation. Furthermore, the silicon-oxygen structure in the nitrile-silicon epoxy flame-retardant phase plays a crucial synergistic role in this process. Its relatively hydrophobic framework characteristics form continuous structural units in the solidified network, thus blocking the penetration path of external media. Simultaneously, the boron-nitrogen coordination sealing phase participates in regulating the pore structure within the system at the microscopic level. The spatial configuration formed by its coordination stabilizes and restricts the micropores that may form during operation. The composite structure formed by these three components within the material allows the system to maintain a relatively consistent structural state under long-term organic medium conditions, providing a basis for the continuation of mechanical response behavior.

[0022] 3. Under thermal and combustion conditions, the phosphazene silicon epoxy flame retardant phase, as the component with the most significant thermal response in the system, participates in structural rearrangement during heating due to its phosphorus- and silicon-containing structures, guiding the overall thermal evolution path of the material. Meanwhile, the catechol phosphonic acid binding phase does not detach from the system during this process. Its aromatic structure and phosphonic acid functional groups participate in the formation of the solid phase structure under high temperature conditions, forming a synergistic evolution relationship with the phosphazene silicon oxide structure. Furthermore, the boron-nitrogen coordination sealing phase still maintains its coordination structure characteristics under heating conditions, and its presence plays a constraining role in maintaining the structural continuity at high temperatures. Through different levels of structural participation during thermal treatment, the three materials jointly influence the structural stability of the material during the combustion stage, causing the system to exhibit controlled evolution behavior under heating conditions. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In this application, the fumed silica used was purchased from Shanghai McLean Biochemical Technology Co., Ltd., with item number F699427.

[0025] Example 1 This embodiment provides a method for preparing a phosphazene silicon epoxy flame retardant phase, including the following steps: Step I: Preparation of allylsilanephosphazene intermediate Weigh out 9.0 g of hexachlorocyclotriphosphazene and 100.0 mL of tetrahydrofuran and add them to the reaction vessel. Stir until dissolved, then purge with nitrogen and cool the reaction vessel to 0°C. Add 6.0 g of p-allylphenol, 8.0 mL of 3-aminopropyltriethoxysilane and 10.0 mL of triethylamine. Keep the mixture warm and stir for 40 min, then raise the temperature of the reaction vessel to 35°C and keep it warm and stir for 5 h. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected to obtain the allylsilanephosphazene intermediate.

[0026] Step II: Preparation of Phosphazene Silicon Oxide Flame Retardant Intermediate Weigh 18.0g of allylsilane phosphazene intermediate and 100.0mL of tetrahydrofuran and add them to the reaction vessel. Stir until the mixture is evenly dispersed. Then add 30.0mL of deionized water and 1.0mL of glacial acetic acid. Heat the reaction vessel to 40℃ and keep it at that temperature for 3 hours. After the reaction is completed, reduce the pressure and distill until no liquid is collected to obtain the phosphazene silicon oxide flame retardant intermediate.

[0027] Step III: Preparation of Phosphazene Silicon Epoxy Flame Retardant Phase Weigh 15.0g of phosphazene silicon oxide flame retardant intermediate and 80.0mL of tetrahydrofuran and add them to the reaction vessel. Stir until the mixture is evenly dispersed, then add 18.0mL of 30wt% hydrogen peroxide aqueous solution and 0.4mL of 98wt% concentrated sulfuric acid. Control the temperature of the reaction vessel at 50℃ and keep it at this temperature for 4 hours. After the reaction is completed, adjust the reaction system to be neutral with saturated ammonia water, and then distill under reduced pressure until no liquid is collected to obtain the phosphazene silicon epoxy flame retardant phase.

[0028] Example 2 This embodiment provides a method for preparing a phosphazene silicon epoxy flame retardant phase, including the following steps: Step I: Preparation of allylsilanephosphazene intermediate Weigh 12.0 g of hexachlorocyclotriphosphazene and 100.0 mL of tetrahydrofuran and add them to the reaction vessel. Stir until dissolved, then purge with nitrogen and cool the reaction vessel to 5 °C. Add 8.0 g of p-allylphenol, 10.0 mL of 3-aminopropyltriethoxysilane and 10.0 mL of triethylamine. Keep the mixture warm and stir for 60 min, then raise the temperature of the reaction vessel to 45 °C and keep it warm and stir for 7 h. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected to obtain the allylsilanephosphazene intermediate.

[0029] Step II: Preparation of Phosphazene Silicon Oxide Flame Retardant Intermediate Weigh 20.0g of allylsilane phosphazene intermediate and 100.0mL of tetrahydrofuran and add them to the reaction vessel. Stir until the mixture is evenly dispersed. Then add 40.0mL of deionized water and 2.0mL of glacial acetic acid. Heat the reaction vessel to 50℃ and keep it at that temperature for 5 hours. After the reaction is completed, reduce the pressure and distill until no liquid is collected to obtain the phosphazene silicon oxide flame retardant intermediate.

[0030] Step III: Preparation of Phosphazene Silicon Epoxy Flame Retardant Phase Weigh 18.0g of phosphazene silicon oxide flame retardant intermediate and 80.0mL of tetrahydrofuran and add them to the reaction vessel. Stir until the mixture is evenly dispersed, then add 21.0mL of 30wt% hydrogen peroxide aqueous solution and 0.6mL of 98wt% concentrated sulfuric acid. Control the temperature of the reaction vessel at 60℃ and keep it at this temperature for 6 hours. After the reaction is completed, adjust the reaction system to be neutral with saturated ammonia water, and then distill under reduced pressure until no liquid is collected to obtain the phosphazene silicon epoxy flame retardant phase.

[0031] Example 3 This embodiment provides a method for preparing a phosphazene silicon epoxy flame retardant phase, including the following steps: Step I: Preparation of allylsilanephosphazene intermediate Weigh 10.0 g of hexachlorocyclotriphosphazene and 100.0 mL of tetrahydrofuran and add them to the reaction vessel. Stir until dissolved, then purge with nitrogen and cool the reaction vessel to 3 °C. Add 7.0 g of p-allylphenol, 9.0 mL of 3-aminopropyltriethoxysilane and 10.0 mL of triethylamine. Keep the mixture warm and stir for 50 min, then raise the temperature of the reaction vessel to 40 °C and keep it warm and stir for 6 h. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected to obtain the allylsilanephosphazene intermediate.

[0032] Step II: Preparation of Phosphazene Silicon Oxide Flame Retardant Intermediate Weigh 19.0g of allylsilane phosphazene intermediate and 100.0mL of tetrahydrofuran and add them to the reaction vessel. Stir until the mixture is evenly dispersed. Then add 35.0mL of deionized water and 1.5mL of glacial acetic acid. Heat the reaction vessel to 45℃ and keep it at that temperature for 4 hours. After the reaction is completed, reduce the pressure and distill until no liquid is collected to obtain the phosphazene silicon oxide flame retardant intermediate.

[0033] Step III: Preparation of Phosphazene Silicon Epoxy Flame Retardant Phase Weigh 16.0g of phosphazene silicon oxide flame retardant intermediate and 80.0mL of tetrahydrofuran and add them to the reaction vessel. Stir until the mixture is evenly dispersed, then add 20.0mL of 30wt% hydrogen peroxide aqueous solution and 0.5mL of 98wt% concentrated sulfuric acid. Control the temperature of the reaction vessel at 55℃ and keep it at this temperature for 5h. After the reaction is completed, adjust the reaction system to be neutral with saturated ammonia water, and then distill under reduced pressure until no liquid is collected to obtain the phosphazene silicon epoxy flame retardant phase.

[0034] Example 4 This embodiment provides a method for preparing a catechol phosphonic acid binder phase, including the following steps: Step ①: Preparation of acrylate catechol monomers Weigh out 10.0 g of catechol and 100.0 mL of dichloromethane and add them to the reaction vessel. Stir until dissolved, then cool the reaction vessel to 0 °C under nitrogen protection. Add 10.0 mL of triethylamine and add acryloyl chloride in ten equal batches at 5 min intervals. The total amount added is 8.0 mL. After the addition is complete, heat the reaction vessel to 20 °C and keep it at that temperature for 3 h with stirring. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected. Store in the dark to obtain acrylate catechol monomer.

[0035] Step 2: Preparation of catechol phosphonic acid binder phase Weigh 12.0g of acrylate catechol monomer and 100.0mL of N,N-dimethylformamide and add them to the reaction vessel. Stir until the mixture is evenly dispersed. Then add 8.0g of vinylphosphonic acid and 1.0g of azobisisobutyronitrile. After purging with nitrogen, heat the reaction vessel to 60℃ and keep it at this temperature for 6 hours. After the reaction is complete, filter the reaction solution and collect the filter cake. Wash the cake three times with deionized water and anhydrous ethanol and then dry it to obtain the catecholphosphonic acid binder phase.

[0036] Example 5 This embodiment provides a method for preparing a catechol phosphonic acid binder phase, including the following steps: Step ①: Preparation of acrylate catechol monomers Weigh out 12.0 g of catechol and 100.0 mL of dichloromethane and add them to the reaction vessel. Stir until dissolved, then cool the reaction vessel to 5 °C under nitrogen protection. Add 12.0 mL of triethylamine and add acryloyl chloride in ten equal batches at 8-minute intervals. The total amount added is 10.0 mL. After the addition is complete, heat the reaction vessel to 25 °C and keep it at that temperature for 5 hours with stirring. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected. Store in the dark to obtain acrylate catechol monomer.

[0037] Step 2: Preparation of catechol phosphonic acid binder phase Weigh out 16.0 g of acrylate catechol monomer and 100.0 mL of N,N-dimethylformamide and add them to the reaction vessel. Stir until the mixture is evenly dispersed. Then add 10.0 g of vinylphosphonic acid and 1.0 g of azobisisobutyronitrile. After purging with nitrogen, heat the reaction vessel to 70 °C and keep it at this temperature for 8 hours. After the reaction is complete, filter the reaction solution and collect the filter cake. Wash the cake three times with deionized water and anhydrous ethanol and then dry it to obtain the catecholphosphonic acid binder phase.

[0038] Example 6 This embodiment provides a method for preparing a catechol phosphonic acid binder phase, including the following steps: Step ①: Preparation of acrylate catechol monomers Weigh out 11.0 g of catechol and 100.0 mL of dichloromethane and add them to the reaction vessel. Stir until dissolved, then cool the reaction vessel to 3 °C under nitrogen protection. Add 11.0 mL of triethylamine, and add acryloyl chloride in ten equal batches at 6 min intervals. The total amount added is 9.0 mL. After the addition is complete, heat the reaction vessel to 25 °C and keep it at that temperature for 4 h with stirring. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected. Store in the dark to obtain acrylate catechol monomer.

[0039] Step 2: Preparation of catechol phosphonic acid binder phase Weigh 15.0g of acrylate catechol monomer and 100.0mL of N,N-dimethylformamide and add them to the reaction vessel. Stir until the mixture is evenly dispersed. Then add 9.0g of vinylphosphonic acid and 1.0g of azobisisobutyronitrile. After purging with nitrogen, heat the reaction vessel to 65℃ and keep it at this temperature for 7 hours. After the reaction is complete, filter the reaction solution and collect the filter cake. Wash the cake three times with deionized water and anhydrous ethanol and then dry it to obtain the catecholphosphonic acid binder phase.

[0040] Example 7 This embodiment provides a method for preparing a corrosion-resistant, flame-retardant, and fireproof sealant material, including the following steps: Step 1: Preparation of boron-nitrogen coordination sealing phase Weigh out 8.0 g boric acid, 10.0 mL triethanolamine and 4.0 mL 1,2-propanediol and add them to the reaction vessel. Stir until the mixture is homogeneous, then heat the reaction vessel to 110 °C. Add 0.6 g 2-methylimidazole and continue heating to 120 °C. Keep the temperature for 2 hours. After the reaction is complete, cool down to below 60 °C and discharge the material. Filter while hot and dry to obtain the boron-nitrogen coordinated sealing phase.

[0041] Step 2: Preparation of sealant material By weight, 40 parts of the phosphazene silicon epoxy flame retardant phase prepared in Example 1, 30 parts of the catechol phosphonic acid adhesive phase prepared in Example 4, and 18 parts of the boron-nitrogen coordination sealing phase were weighed and added to a vacuum stirring vessel. The vacuum stirring vessel was heated to 25°C and stirred for 20 minutes. Then, 6 parts of dioctyl phthalate were added and stirred for another 15 minutes. Then, 4 parts of fumed silica were added and stirred until uniform and free of dry powder agglomerates. Vacuum degassing was then performed to obtain the sealant material.

[0042] Example 8 This embodiment provides a method for preparing a corrosion-resistant, flame-retardant, and fireproof sealant material, including the following steps: Step 1: Preparation of boron-nitrogen coordination sealing phase Weigh out 10.0 g boric acid, 12.0 mL triethanolamine and 6.0 mL 1,2-propanediol and add them to the reaction vessel. Stir until the mixture is homogeneous, then heat the reaction vessel to 120 °C. Add 0.8 g 2-methylimidazole and continue heating to 130 °C. Keep the temperature for 4 h. After the reaction is complete, cool down to below 60 °C and discharge the material. Filter while hot and dry to obtain the boron-nitrogen coordinated sealing phase.

[0043] Step 2: Preparation of sealant material By weight, 50 parts of the phosphazene silicon epoxy flame retardant phase prepared in Example 2, 40 parts of the catechol phosphonic acid adhesive phase prepared in Example 5, and 21 parts of the boron-nitrogen coordination sealing phase were weighed and added to a vacuum stirring vessel. The vacuum stirring vessel was heated to 35°C and stirred for 40 minutes. Then, 8 parts of dioctyl phthalate were added and stirred for another 25 minutes. Then, 6 parts of fumed silica were added and stirred until uniform and free of dry powder agglomerates. Vacuum degassing was then performed to obtain the sealant material.

[0044] Example 9 This embodiment provides a method for preparing a corrosion-resistant, flame-retardant, and fireproof sealant material, including the following steps: Step 1: Preparation of boron-nitrogen coordination sealing phase Weigh out 9.0 g boric acid, 12.0 mL triethanolamine and 5.0 mL 1,2-propanediol and add them to the reaction vessel. Stir until the mixture is homogeneous, then heat the reaction vessel to 115 °C. Add 0.7 g 2-methylimidazole and continue heating to 125 °C. Keep the temperature for 3 h. After the reaction is complete, cool down to below 60 °C and discharge the material. Filter while hot and dry to obtain the boron-nitrogen coordinated sealing phase.

[0045] Step 2: Preparation of sealant material By weight, 45 parts of the phosphazene silicon epoxy flame retardant phase prepared in Example 3, 35 parts of the catechol phosphonic acid adhesive phase prepared in Example 6, and 20 parts of the boron-nitrogen coordination sealing phase were weighed and added to a vacuum stirring vessel. The vacuum stirring vessel was heated to 30°C and stirred for 30 minutes. Then, 7 parts of dioctyl phthalate were added and stirred for another 20 minutes. Then, 5 parts of fumed silica were added and stirred until uniform and free of dry powder agglomerates. Vacuum degassing was then performed to obtain the sealant material.

[0046] Comparative Example 1 The difference between this comparative example and Example 9 is that the boron-nitrogen coordination sealing phase is omitted in step two.

[0047] Comparative Example 2 The difference between this comparative example and Example 9 is that the addition of azobisisobutyronitrile (AIBN) is omitted in step ② of the preparation process of the catecholphosphonic acid binder phase used in step 2.

[0048] Comparative Example 3 The difference between this comparative example and Example 9 is that, in the preparation process of the phosphazene silicon epoxy flame retardant phase used in step two, step III is omitted, and the phosphazene silicon oxide flame retardant intermediate prepared in step II is used to replace the phosphazene silicon epoxy flame retardant phase in an equal amount.

[0049] Performance testing: The sealant materials prepared in Examples 7-9 and Comparative Examples 1-3 were vacuum degassed and then injected onto the substrate surface. They were first allowed to stand and cure for 24 hours at 25°C and 50%RH, and then heated and cured at 80°C for 2 hours. After curing, the samples were cooled to room temperature to obtain cured sealant. The tensile adhesion and flame retardant properties of the cured sealant materials prepared using Examples 7-9 and Comparative Examples 1-3 were tested in accordance with the standard GB / T 24267-2009 "Flame-retardant sealants for building". The tensile adhesion change rate of the cured sealant obtained after curing using the sealant materials prepared in Examples 7-9 and Comparative Examples 1-3 after liquid corrosion was tested in accordance with the standard GB / T 1690-2010 "Test Method for Liquid Resistance of Vulcanized Rubber or Thermoplastic Rubber". See Table 1 for specific data; Table 1 - Performance Test Data for Each Sample

[0050] Data Analysis: Comparative analysis of the data in Table 1 reveals that the sealant material prepared in this invention has a tensile modulus of 0.63 MPa, an elongation at break of 385%, and a smoky burning time of 8 s after curing. Furthermore, after corrosion, the change rate of tensile modulus is -4.6%, and the change rate of elongation at break is -6.4%. All these data are superior to the comparative example, indicating that… In Comparative Example 1, since no boron-nitrogen coordination sealing phase was introduced in the sealant preparation step, the system lacks an effective control unit for the multiphase interface and micropore structure. During curing and subsequent use, although the phosphazene silicon epoxy flame retardant phase and the catechol phosphonic acid adhesive phase can still form a basic composite structure, structural discontinuity is more likely to occur in the interface region between different phases. Under the action of stress or environmental media, this interface state is difficult to constrain the formation and evolution of micropores, causing the stress transmission path in local areas to tend to be dispersed. At the same time, the disordered development of the pore structure provides a channel for the penetration of moisture and other media, further aggravating the disturbance of the internal structure of the system. The above factors work together to make it difficult for the material to maintain the original overall structural stability under long-term operating conditions, thus showing a downward trend in comprehensive performance. In Comparative Example 2, because the addition of the free radical initiator was omitted during the preparation of the catechol phosphonic acid adhesive phase, the relevant components failed to form a stable structured adhesive phase through polymerization. This change resulted in the introduced catechol phosphonic acid component existing mainly in the form of low molecular weight or weak interaction in the sealant system, making it difficult to achieve effective integration in the continuous structure composed of phosphazene, silicon, and epoxy flame retardant phases. During system operation, the effect of this type of component on the multiphase interface is more of a local effect rather than a synergistic participation, thereby weakening the mechanical coupling and environmental response consistency between different phases. Under the action of external forces or media, relative slippage or local mismatch is prone to occur in the structure, causing the overall response of the system to tend to be non-synergistic, thus affecting the comprehensive performance of the composite material. In Comparative Example 3, the phosphazene silicon epoxy flame retardant phase was introduced directly into the system as a phosphazene silicon oxide flame retardant intermediate without undergoing an epoxidation reaction step. This limited its ability to participate at the structural level. Due to the lack of reactivity provided by epoxy groups, this component was difficult to participate in the construction of the overall network as a continuous structural unit in the sealant system. Its mode of action was more inclined to be a functional dispersed phase. Under this structural configuration, although other components still existed in the system, there was a lack of a unified structural carrier for effective coupling, making it difficult to establish synergistic relationships between multiple phases. During the process of being heated, stressed, or subjected to environmental media, the structural evolution behavior was more likely to exhibit dispersion characteristics, resulting in a decrease in the overall structural stability and operational consistency of the material, thus reflecting a weakening trend in composite performance. In conclusion, when the flame-retardant phase, adhesive phase, or sealing phase in the sealant system does not participate in the system construction in a structured manner according to the present invention, the synergistic relationship between the multiple phases shows a weakening trend to varying degrees. Specifically, the absence of interface control units makes the microstructure evolution lack stable constraints, the non-participation of network building units in structure formation weakens the consistency of interphase coupling, and the reduction in the reactivity of the main structural units limits the continuity of the overall network. The above changes occur at different levels such as pore control, interface coupling, and skeleton construction, but all make the system more prone to exhibiting dispersed response characteristics rather than a unified and coordinated operating state during stress or environmental action. It can be seen that whether each component of the material participates in the system construction in a predetermined structural form has a direct impact on the operational stability and structural consistency of the composite system, and its configuration and participation path are of key significance in the overall technical solution.

[0051] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0052] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0053] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A corrosion-resistant, flame-retardant, and fireproof sealant material, characterized in that, The raw material composition includes the following parts by weight: 40-50 parts phosphazene silicon epoxy flame retardant phase, 30-40 parts catechol phosphonic acid binder phase, 18-21 parts boron nitrogen coordination sealing phase, 6-8 parts dioctyl phthalate and 4-6 parts fumed silica. The preparation method of the phosphazene silicon epoxy flame retardant phase is as follows: A1. Add allylsilane phosphazene intermediate and tetrahydrofuran to a reaction vessel and stir until evenly dispersed. Then add deionized water and glacial acetic acid. Heat the reaction vessel to 40-50℃ and keep it at that temperature for 3-5 hours. After the reaction is completed, reduce the pressure and distill until no liquid is collected to obtain phosphazene silicon oxide flame retardant intermediate. A2. Add the phosphazene silicon oxide flame retardant intermediate and tetrahydrofuran to the reaction vessel and stir until evenly dispersed. Then add the oxidant and 98wt% concentrated sulfuric acid. Control the temperature of the reaction vessel at 50-60℃ and keep it warm and stir for 4-6 hours. The post-treatment yields the phosphazene silicon epoxy flame retardant phase.

2. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 1, characterized in that, In step A1, the ratio of allyl silane phosphazene intermediate, tetrahydrofuran, deionized water and glacial acetic acid is 18-20g:100mL:30-40mL:1-2mL.

3. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 1, characterized in that, In step A2, the ratio of phosphazene silicon oxide flame retardant intermediate, tetrahydrofuran, oxidant and 98wt% concentrated sulfuric acid is 15-18g:80mL:18-21mL:0.4-0.6mL, wherein the oxidant is a 30wt% aqueous solution of hydrogen peroxide.

4. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 1, characterized in that, The preparation method of the allylsilane phosphazene intermediate is as follows: Hexachlorocyclotriphosphazene and tetrahydrofuran are added to a reaction vessel and stirred until dissolved. Nitrogen gas is introduced for protection and the reaction vessel is cooled to 0-5°C. Then, p-allylphenol, 3-aminopropyltriethoxysilane and triethylamine are added. The mixture is kept warm and stirred for 40-60 min. The temperature of the reaction vessel is then raised to 35-45°C and kept warm and stirred for 5-7 h. After the reaction is completed, the mixture is filtered to remove salt and then distilled under reduced pressure until no liquid is collected to obtain the allylsilane phosphazene intermediate.

5. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 4, characterized in that, The ratio of hexachlorocyclotriphosphazene, tetrahydrofuran, p-allylphenol, 3-aminopropyltriethoxysilane and triethylamine is 9-12g:100mL:6-8g:8-10mL:10mL.

6. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 1, characterized in that, The catechol phosphonic acid binder phase was prepared by the following method: B1. Add catechol and dichloromethane to the reactor and stir until dissolved. Cool the reactor to 0-5°C under nitrogen protection. Add triethylamine and add acryloyl chloride in ten equal batches with an interval of 5-8 minutes between additions. After the addition is complete, heat the reactor to 20-25°C and keep it at this temperature for 3-5 hours. After the reaction is complete, filter to remove salt and distill under reduced pressure until no liquid is collected. Store in the dark to obtain acrylate catechol monomer. B2. Add acrylate catechol monomer and N,N-dimethylformamide to the reactor and stir. After uniform dispersion, add vinylphosphonic acid and azobisisobutyronitrile. After nitrogen protection, heat the reactor to 60-70℃ and stir for 6-8 hours. Post-treatment yields the catecholphosphonic acid binder phase.

7. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 6, characterized in that, In step B1, the ratio of catechol, dichloromethane, triethylamine, and acryloyl chloride is 10-12g:100mL:10-12mL:8-10mL; in step B2, the ratio of acrylated catechol monomer, N,N-dimethylformamide, vinylphosphonic acid, and azobisisobutyronitrile is 12-16g:100mL:8-10g:1g.

8. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 1, characterized in that, The boron-nitrogen coordination sealing phase is prepared by adding boric acid, triethanolamine and 1,2-propanediol into a reaction vessel and stirring until they are mixed evenly. The reaction vessel is then heated to 110-120°C, followed by the addition of 2-methylimidazole. The temperature is then raised to 120-130°C and the reaction is maintained for 2-4 hours. The boron-nitrogen coordination sealing phase is then obtained after post-treatment.

9. The corrosion-resistant, flame-retardant, and fireproof sealant material according to claim 8, characterized in that, In the preparation of the boron-nitrogen coordinated sealing phase, the ratio of boric acid, triethanolamine, 1,2-propanediol and 2-methylimidazole is 8-10g:10-12mL:4-6mL:0.6-0.8g.

10. A method for preparing a corrosion-resistant, flame-retardant, and fireproof sealant material as described in any one of claims 1-9, characterized in that, Includes the following steps: Phosphazene silicon epoxy flame retardant phase, catechol phosphonic acid binder phase and boron nitrogen coordination sealing phase are added to a vacuum stirring vessel. The vacuum stirring vessel is heated to 25-35℃ and stirred for 20-40 minutes. Then, dioctyl phthalate is added and stirred for another 15-25 minutes. Fumed silica is then added and stirred until uniform and free of dry powder agglomerates. Vacuum degassing is then performed to obtain the sealant material.

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