High performance end silyl polyether based sealant and method of making same

Abstract

This invention discloses a high-performance silane-terminated polyether sealant and its preparation method, belonging to the field of sealant technology. Through the synergistic effect between its components, this invention significantly improves the overall performance of the material, effectively overcoming the technical problems of low mechanical strength, poor extrudability, and poor long-term heat and oxygen aging resistance in existing technologies. While significantly improving mechanical properties, the sealant also exhibits significantly improved extrudability, making the adhesive smoother and easier to apply during construction, greatly improving construction efficiency and convenience. The resulting sealant can be widely used for bonding and sealing in building structures, high-quality home decoration, transportation vehicles, and precision equipment manufacturing, where stringent heat resistance and sealing requirements are required.

Description

Technical Field

[0001] This invention relates to the field of sealant technology, specifically to a high-performance silane-terminated polyether sealant and its preparation method. Background Technology

[0002] Silyl polyether sealants are a class of high-performance sealing materials based on silyl polyether polymers. Their main chain is a flexible polyether structure with hydrolyzable silyl groups grafted at the ends. Under the influence of ambient moisture, the silyl groups hydrolyze and condense to form a three-dimensional network structure with Si-O-Si bonds at its core, achieving curing from a paste to an elastomer. This material innovatively combines the flexibility, low modulus, and paintability of polyether segments with the weather resistance and temperature resistance of silicone chemistry. It overcomes the shortcomings of traditional polyurethane sealants, such as water sensitivity and easy foaming, and silicone sealants, such as difficulty in painting and easy contamination. It is widely used in precision sealing and bonding in fields such as construction, automotive, and rail transportation.

[0003] Despite the excellent overall performance of silane polyether sealants, their current research and technological development still face several key challenges that restrict their application in more demanding or high-end scenarios. For example, their mechanical strength is relatively low, making it difficult to meet the requirements of high-strength structural bonding. In pursuit of high strength, a large amount of filler is often added, which leads to poor extrudability of the colloid and makes construction difficult.

[0004] Chinese patent document CN121379473A discloses a high thermal conductivity modified silane polyether adhesive and its preparation method. The modified filler in this patent is a hydroxylated AlN filler or a hydroxylated BN filler or a composite filler of hydroxylated AlN and hydroxylated BN. The filler is grafted with silane under weak acid catalysis to form a SiOAl or / and SiOB covalent network, and then mixed with nano-silica particles coated with polydopamine. Although the dispersion performance of the filler can be improved by steric hindrance and physical barriers, there is still room for further improvement in its interfacial bonding ability with polyether segments. At the same time, the antioxidant in this patent is physically mixed. Physically mixed antioxidants may have problems such as migration or consumption too quickly, thus affecting the long-term antioxidant performance and overall durability of the sealant system. Summary of the Invention

[0005] The main objective of this invention is to propose a high-performance silane-terminated polyether sealant and its preparation method. Firstly, by introducing Schiff base compounds onto the surface of montmorillonite, the covalently bonded flexible polyether amine chains significantly improve the dispersibility and interfacial compatibility of montmorillonite in the polyether resin matrix. This enhances the mechanical properties of the sealant while optimizing extrusion performance, effectively resolving the conflict between mechanical properties and workability. Secondly, by introducing quinoline rings with thermo-oxidative aging resistance onto the surface of montmorillonite, the sealant is endowed with long-term thermo-oxidative aging resistance, achieving a synergistic improvement in efficient filler dispersion in the resin matrix, optimized workability, enhanced interfacial structure, and long-term thermo-oxidative aging resistance.

[0006] To achieve the above objectives, this invention proposes a high-performance silane-terminated polyether sealant, comprising the following components by weight: 20-40 parts silane-terminated polyether resin, 30-50 parts modified filler, 0.5-3 parts silane coupling agent, 0.1-1 parts catalyst, 10-25 parts plasticizer, and 0.5-2 parts dehydrating agent; wherein the modified filler is Schiff base-modified montmorillonite; and the Schiff base is obtained by reacting polyether amine with 8-hydroxyquinoline-2-carboxaldehyde.

[0007] Based on the above technical solutions, preferably, the preparation method of the modified filler is as follows: S1. A Schiff base intermediate is obtained by reacting polyetheramine and 8-hydroxyquinoline-2-carboxaldehyde with a Schiff base. S2. Pretreated montmorillonite is obtained by intercalation modification with quaternary ammonium salt and then surface treatment with KH560. S3, the Schiff base intermediate, undergoes a ring-opening reaction with pretreated montmorillonite to obtain the modified filler.

[0008] Based on the above technical solutions, a further preferred method for preparing the modified filler includes the following steps: S1. Dissolve 8-hydroxyquinoline-2-carboxaldehyde in anhydrous ethanol, add polyetheramine dropwise, heat and react. After the reaction is complete, the Schiff base intermediate is obtained through post-treatment. S2. Disperse montmorillonite in water, add hexadecyltrimethylammonium bromide, stir to react, filter, collect the solid, wash and dry it, disperse it in a mixed solution of ethanol and water, add KH560, heat to react, and obtain pretreated montmorillonite after post-treatment. S3. Disperse the pretreated montmorillonite into toluene, add Schiff base intermediate, TBD and benzyltrimethylammonium chloride, heat to react, and obtain the modified filler after post-treatment.

[0009] Based on the above technical solution, a further preferred embodiment is that in step S1, the mass ratio of 8-hydroxyquinoline-2-carboxaldehyde to polyetheramine is 0.5-0.8:1; the reaction temperature is 50-70℃, and the reaction time is 5-8 hours. In this step, by controlling the mass ratio of 8-hydroxyquinoline-2-carboxaldehyde to polyetheramine, it is ensured that the aldehyde group on 8-hydroxyquinoline-2-carboxaldehyde can react with the amino group on polyetheramine to form a Schiff base, thereby preparing a Schiff base intermediate, and retaining the phenolic hydroxyl group on 8-hydroxyquinoline for subsequent ring-opening reactions.

[0010] Based on the above technical solution, a further preferred embodiment is that the mass ratio of montmorillonite, hexadecyltrimethylammonium bromide, and KH560 in step S2 is 10:3-7:0.1-0.5. Montmorillonite is an inorganic reinforcing filler, and its addition to the sealant can reinforce the sealant. In this step, hexadecyltrimethylammonium bromide is used for intercalation modification, which can effectively increase the interlayer spacing of montmorillonite, making it easier to peel off and disperse uniformly in the resin matrix, forming a nanoscale lamellar dispersed phase. These dispersed lamellars can not only improve the mechanical properties of the sealant through the nano-effect, but also form a dense physical barrier in the matrix, prolonging the diffusion path of aging media such as oxygen and water, significantly slowing down their diffusion rate, and effectively improving the sealant's resistance to thermo-oxidative aging. Then, epoxy groups are introduced on its surface, which is beneficial to subsequent reactions.

[0011] Based on the above technical solution, a further preferred embodiment is that the mass ratio of pretreated montmorillonite to Schiff base intermediate in step S3 is 10:2-5. In this step, the active hydroxyl groups on the Schiff base intermediate undergo a ring-opening reaction with the epoxy groups on the surface of the pretreated montmorillonite, thereby fixing quinoline rings and flexible polyetheramine long chains on the montmorillonite surface. The quinoline rings impart excellent thermo-oxidative stability to the sealant, making it difficult for the polymer matrix to decompose or rearrange at high temperatures. This effectively inhibits the breakage and degradation of polymer chains under thermal action, fixing them onto the montmorillonite and preventing them from falling off, further improving the heat aging resistance of the sealant. Through the introduction of polyetheramine segments, its main chain structure is similar to that of the pretreated montmorillonite. The main resin of the sealant, silane-terminated polyether, has extremely high chemical similarity and thermodynamic compatibility, effectively improving its compatibility with the polyether resin matrix and strengthening interfacial interactions. This not only effectively prevents the aggregation of nano-montmorillonite sheets, ensuring their long-term uniform and stable dispersion in the resin matrix, but also significantly reduces the sealant's application viscosity, improves the material's extrusion performance, making it smoother and easier to handle during application, and increasing construction efficiency. Furthermore, through the physical entanglement and chemical similarity of the long polyether chains, a strong and homogeneous transition interface is formed between the filler and the resin matrix, greatly enhancing stress transfer efficiency and thus more fully leveraging the reinforcing and toughening effects of the nanofiller.

[0012] Based on the above technical solutions, preferably, the silane coupling agent is at least one of A-1120, KH550, and KH560; the silane coupling agent molecule contains two groups with different chemical properties, which can serve as a bridge for the bonding of different materials, thereby improving the adhesion of the sealant to the material; it can also serve as a new crosslinking point to enhance the crosslinking effect inside the polymer.

[0013] Based on the above technical solutions, preferably, the catalyst is an organotin and / or a tertiary amine catalyst; more preferably, the catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, and dihydroxybutyltin chloride.

[0014] Based on the above technical solutions, preferably, the plasticizer is a phthalate plasticizer and / or a polyether glycol plasticizer; the plasticizer can improve the flowability, flexibility, plasticity and viscoelasticity of the sealant, as well as reduce its hardness and brittleness.

[0015] Based on the above technical solutions, preferably, the dehydrating agent is an alkoxysilane; it has good compatibility with the sealant, and its hydrolyzable groups are more active than the alkoxy groups in the system, reacting with moisture first when it comes into contact with water, thereby achieving the effect of controlling the moisture content of the sealant.

[0016] The present invention also provides a method for preparing the high-performance silane-terminated polyether sealant, comprising the following steps: mixing silane-terminated polyether resin, modified filler, silane coupling agent, catalyst, plasticizer, and dehydrating agent evenly, then degassing, discharging, and sealing to obtain the high-performance silane-terminated polyether sealant.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) This invention provides a high-performance silane-terminated polyether sealant. Through the synergistic effect between the components, the overall performance of the material is significantly improved, effectively overcoming the technical problems of low mechanical strength, poor extrudability, and poor long-term heat and oxygen aging resistance in the prior art. While the mechanical properties are greatly improved, the extrusion performance of this sealant is significantly improved, which makes the colloid smoother and easier to operate during construction, greatly improving construction efficiency and convenience. The resulting sealant can be widely used for bonding and sealing in building structures, high-quality home decoration, transportation vehicles, and precision equipment manufacturing, where heat resistance and sealing performance requirements are stringent. 2) The modified filler of this invention is prepared by reacting a Schiff base compound obtained by reacting a flexible polyether long-chain polyetheramine with 8-hydroxyquinoline-2-carboxaldehyde with pretreated montmorillonite. The polyether long chain has extremely high chemical similarity with the main resin of the sealant, which can effectively strengthen the interface between the filler and the matrix and significantly improve the stress transfer efficiency, thereby greatly enhancing the reinforcing and toughening effect and mechanical properties of the sealant. At the same time, the covalently bonded quinoline ring of the Schiff base endows montmorillonite with excellent long-term heat and oxygen aging resistance. The pretreatment of montmorillonite increases the interlayer spacing, promotes efficient dispersion and extends the diffusion path of oxygen and water aging media, further synergistically improving the overall heat and oxygen aging resistance. By improving the filler, the efficient dispersion of the filler in the resin matrix, the optimization of construction performance, the strengthening of the interface and the synergistic improvement of long-term heat and oxygen aging resistance are achieved. Detailed Implementation

[0018] The sources of some of the raw materials in the embodiments of the present invention are as follows. Unless otherwise specified, the raw materials used in the embodiments can be obtained from conventional commercial channels or can be prepared by conventional methods.

[0019] The sources of some of the raw materials used in this invention are as follows: Silane-terminated polyether resin, model S303H, Kanekachi Chemical Co., Ltd., Japan.

[0020] Montmorillonite, 325 mesh, purchased from Bochuan Mineral Products Processing Plant in Lingshou County.

[0021] Polyetheramine, Jeffamine M-600, Huntsman.

[0022] Example 1 A method for preparing a high-performance silane-terminated polyether sealant includes the following steps: In a high-speed mixer, 30g of silane-terminated polyether resin, 40g of modified filler, 0.5g of KH550, 0.6g of dibutyltin diacetate, 18g of dibutyl phthalate, and 1.2g of vinyltris(β-methoxyethoxy)silane are mixed evenly at 50°C, degassed, discharged, and sealed to obtain a high-performance silane-terminated polyether sealant.

[0023] The modified filler is prepared as follows: S1. Dissolve 6.5g of 8-hydroxyquinoline-2-carboxaldehyde in 200mL of anhydrous ethanol, add 10g of polyetheramine dropwise, heat to 60℃ and react for 6h. After the reaction is completed, remove the solvent under reduced pressure to obtain the Schiff base intermediate. S2. Weigh 10g of montmorillonite and disperse it in 200mL of water. While stirring, add 5g of hexadecyltrimethylammonium bromide and react at 60℃ for 5h. After the reaction is complete, filter and collect the solid product, wash and dry it, and disperse it in 250mL of a mixed solution of ethanol and water (volume ratio 1:1). Then, add 0.5g of KH560 (γ-glycidoxypropyltrimethoxysilane), heat the system to 50℃, and stir and react for 4h. After the reaction is complete, filter and collect the solid again, wash and dry it to constant weight to obtain pretreated montmorillonite. S3. Disperse 10g of pretreated montmorillonite into 200mL of toluene, add 3.5g of Schiff base intermediate, 0.3g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and 0.08g of benzyltrimethylammonium chloride, and heat the mixture to 110°C under nitrogen protection for 9 hours. After the reaction is completed, cool to room temperature, collect the solid product by suction filtration, wash and dry to constant weight to obtain the modified filler.

[0024] Example 2 A method for preparing a high-performance silane-terminated polyether sealant includes the following steps: In a high-speed mixer, 20g of silane-terminated polyether resin, 30g of modified filler, 2g of KH550, 0.1g of dibutyltin diacetate, 10g of dibutyl phthalate, and 0.5g of vinyltris(β-methoxyethoxy)silane are mixed evenly at 50°C, then degassed, discharged, and sealed to obtain a high-performance silane-terminated polyether sealant.

[0025] The modified filler is prepared as follows: S1. Dissolve 5g of 8-hydroxyquinoline-2-carboxaldehyde in 200mL of anhydrous ethanol, add 10g of polyetheramine dropwise, heat to 50℃ and react for 5h. After the reaction is completed, remove the solvent under reduced pressure to obtain the Schiff base intermediate. S2. Weigh 10g of montmorillonite and disperse it in 200mL of water. While stirring, add 3g of hexadecyltrimethylammonium bromide and react at 50℃ for 6h. After the reaction is complete, filter and collect the solid product, wash and dry it, and disperse it in 250mL of a mixed solution of ethanol and water (volume ratio 1:1). Then, add 0.3g of KH560 (γ-glycidoxypropyltrimethoxysilane), heat the system to 50℃, and stir and maintain the temperature for 4 hours. After the reaction is complete, filter and collect the solid again, wash and dry it to constant weight to obtain pretreated montmorillonite. S3. Disperse 10g of pretreated montmorillonite into 200mL of toluene, add 2g of Schiff base intermediate, 0.1g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 0.05g of benzyltrimethylammonium chloride. Under nitrogen protection, heat the mixture to 110℃ for reaction for 9 hours. After the reaction is completed, cool to room temperature, collect the solid product by suction filtration, wash and dry to constant weight to obtain the modified filler.

[0026] Example 3 A method for preparing a high-performance silane-terminated polyether sealant includes the following steps: In a high-speed mixer, 40g of silane-terminated polyether resin, 50g of modified filler, 3g of KH550, 1g of dibutyltin diacetate, 25g of dibutyl phthalate, and 2g of vinyltris(β-methoxyethoxy)silane are mixed evenly at 50°C, then degassed, discharged, and sealed to obtain a high-performance silane-terminated polyether sealant.

[0027] The modified filler is prepared as follows: S1. Dissolve 8g of 8-hydroxyquinoline-2-carboxaldehyde in anhydrous ethanol, add 10g of polyetheramine dropwise, heat to 50℃ and react for 5h. After the reaction is completed, remove the solvent under reduced pressure to obtain the Schiff base intermediate. S2. Weigh 10g of montmorillonite and disperse it in 200mL of water. While stirring, add 7g of hexadecyltrimethylammonium bromide and react at 60℃ for 5h. After the reaction is complete, filter and collect the solid product, wash and dry it, and disperse it in 250mL of a mixed solution of ethanol and water (volume ratio 1:1). Then, add 0.5g of KH560 (γ-glycidoxypropyltrimethoxysilane), heat the system to 50℃, and stir and maintain the temperature for 3 hours. After the reaction is complete, filter and collect the solid again, wash and dry it to constant weight to obtain pretreated montmorillonite. S3. Disperse 10g of pretreated montmorillonite into 200mL of toluene, add 5g of Schiff base intermediate, 0.5g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 0.1g of benzyltrimethylammonium chloride. Under nitrogen protection, heat the mixture to 110℃ for 9 hours. After the reaction is complete, cool to room temperature, collect the solid product by suction filtration, wash and dry to constant weight to obtain the modified filler.

[0028] Comparative Example 1 A method for preparing a high-performance silane-terminated polyether sealant is similar to that in Example 1, except that polyether amine is not added to the modified filler. The preparation method of the modified filler is as follows: S1. Weigh 10g of montmorillonite and disperse it in 200mL of water. Add 5g of hexadecyltrimethylammonium bromide while stirring. React at 60℃ for 5h. After the reaction is complete, filter and collect the solid product. Wash and dry the product and disperse it in 250mL of a mixed solution of ethanol and water (volume ratio 1:1). Then, add 0.5g of KH560 (γ-glycidoxypropyltrimethoxysilane). Heat the system to 40℃ and stir for 4h. After the reaction is complete, filter and collect the solid again. Wash and dry to constant weight to obtain pretreated montmorillonite. S2. Disperse 10g of pretreated montmorillonite into 200mL of toluene, add 3.5g of 8-hydroxyquinoline-2-carboxaldehyde, 0.3g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 0.08g of benzyltrimethylammonium chloride. Under nitrogen protection, heat the mixture to 110℃ for 9 hours. After the reaction is complete, cool to room temperature, collect the solid product by suction filtration, wash and dry to constant weight to obtain the modified filler.

[0029] Comparative Example 2 A method for preparing a high-performance silane-terminated polyether sealant is similar to that in Example 1, except that 8-hydroxyquinoline-2-carboxaldehyde is not added to the modified filler. The preparation method of the modified filler is as follows: S1. Weigh 10g of montmorillonite and disperse it in 200mL of water. Add 5g of hexadecyltrimethylammonium bromide while stirring. React at 60℃ for 5h. After the reaction is complete, filter and collect the solid product. Wash and dry the product and disperse it in 250mL of a mixed solution of ethanol and water (volume ratio 1:1). Then, add 0.5g of KH560 (γ-glycidoxypropyltrimethoxysilane). Heat the system to 50℃ and stir for 4h. After the reaction is complete, filter and collect the solid again. Wash and dry to constant weight to obtain pretreated montmorillonite. S2. Disperse 10g of pretreated montmorillonite into 200mL of toluene, add 3.5g of polyetheramine, 0.3g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 0.08g of benzyltrimethylammonium chloride. Under nitrogen protection, heat the mixture to 110°C for 9 hours. After the reaction is complete, cool to room temperature, collect the solid product by suction filtration, wash and dry to constant weight to obtain the modified filler.

[0030] Comparative Example 3 A method for preparing a high-performance silane-terminated polyether sealant is similar to that in Example 1, except that the polyether amine in the modified filler is physically mixed; the preparation method of the modified filler is as follows: S1. Weigh 10g of montmorillonite and disperse it in 200mL of water. Add 5g of hexadecyltrimethylammonium bromide while stirring. React at 60℃ for 5h. After the reaction is complete, filter and collect the solid product. Wash and dry the product and disperse it in 250mL of a mixed solution of ethanol and water (volume ratio 1:1). Then, add 0.5g of KH560 (γ-glycidoxypropyltrimethoxysilane). Heat the system to 50℃ and stir for 4h. After the reaction is complete, filter and collect the solid again. Wash and dry to constant weight to obtain pretreated montmorillonite. S2. Mix 10g of pretreated montmorillonite and 3.5g of polyetheramine evenly to obtain the modified filler.

[0031] Comparative Example 4 A method for preparing a high-performance silane-terminated polyether sealant is similar to that in Example 1, except that the 8-hydroxyquinoline-2-carboxaldehyde in the modified filler is physically mixed; the preparation method of the modified filler is as follows: S1. Weigh 10g of montmorillonite and disperse it in 200mL of water. Add 5g of hexadecyltrimethylammonium bromide while stirring. React at 60℃ for 5h. After the reaction is complete, filter and collect the solid product. Wash and dry the product and disperse it in 250mL of a mixed solution of ethanol and water (volume ratio 1:1). Then, add 0.5g of KH560 (γ-glycidoxypropyltrimethoxysilane). Heat the system to 50℃ and stir for 4h. After the reaction is complete, filter and collect the solid again. Wash and dry to constant weight to obtain pretreated montmorillonite. S2. Mix 10g of pretreated montmorillonite and 3.5g of 8-hydroxyquinoline-2-carboxaldehyde evenly to obtain the modified filler.

[0032] Test methods and results The high-performance silane-terminated polyether sealants prepared in Comparative Examples 1-4 and Examples 1-3 were used as test objects, and their performance was tested under standard conditions: temperature 23±1℃ and humidity 50%±5%. Extrudability: Measured according to GB / T 13477.3-2017. Place the sealant sample in a curing chamber for 1 day under standard test conditions. Fill the sealant into a dedicated polyethylene cartridge, ensuring no air bubbles during filling. Assemble the extrusion cartridge into a pneumatic glue gun and connect it to compressed air at (200±2.5) kPa. Set a time of 30 seconds, and extrude the sealant from the glue gun. Stop extruding after the predetermined time and measure the mass of sealant extruded during this period. Repeat the above process at least three times. Divide the mass of the extruded sealant sample by the extrusion time to obtain the sealant's extrusion rate per minute. Tensile properties and breaking strength: I-shaped specimens were prepared according to GB / T 13477.8-2017. The prepared specimens were cured under standard test conditions for 28 days. The test was carried out at (23±2)℃, and three specimens from the same batch were tested. The isolation pads on the specimens were removed, and the specimens were put into a tensile testing machine and stretched to failure at a speed of (5.5±0.7) mm / min. The tensile properties and elongation at break were measured, and the average value of the test results was taken. Thermal aging performance: I-shaped specimens were prepared according to GB / T 13477.8-2017, and then the specimens were cured under standard test conditions for 28 days. After aging in a 90℃ oven for 60 days, the specimens were taken out and their tensile properties and elongation at break were tested.

[0033] The test results are shown in Table 1: Table 1 Performance test results of high-performance silane-terminated polyether sealants

[0034] As can be seen from the experimental results in the table, the high-performance silane-terminated polyether sealant obtained by this invention has good extrudability, mechanical properties and heat aging resistance.

[0035] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A high-performance silane-terminated polyether sealant, characterized in that: The product comprises the following components by weight: 20-40 parts silane-terminated polyether resin, 30-50 parts modified filler, 0.5-3 parts silane coupling agent, 0.1-1 parts catalyst, 10-25 parts plasticizer, and 0.5-2 parts dehydrating agent; the modified filler is Schiff base modified montmorillonite; the Schiff base is obtained by reacting polyether amine with 8-hydroxyquinoline-2-carboxaldehyde.

2. The sealant according to claim 1, characterized in that, The modified filler is prepared by: S1. A Schiff base intermediate is obtained by reacting polyetheramine and 8-hydroxyquinoline-2-carboxaldehyde with a Schiff base. S2. Pretreated montmorillonite is obtained by intercalation modification with quaternary ammonium salt and then surface treatment with KH560. S3, Schiff base intermediate, undergoes a ring-opening reaction with pretreated montmorillonite to obtain modified filler.

3. The sealant according to claim 2, characterized in that, The method for preparing the modified filler includes the following steps: S1. Dissolve 8-hydroxyquinoline-2-carboxaldehyde in anhydrous ethanol, add polyetheramine dropwise, heat and react. After the reaction is complete, the Schiff base intermediate is obtained through post-treatment. S2. Disperse montmorillonite in water, add hexadecyltrimethylammonium bromide, stir to react, filter, collect the solid, wash and dry it, disperse it in a mixed solution of ethanol and water, add KH560, heat to react, and obtain pretreated montmorillonite after post-treatment. S3. Disperse the pretreated montmorillonite into toluene, add Schiff base intermediate, TBD and benzyltrimethylammonium chloride, heat to react, and obtain the modified filler after post-treatment.

4. The sealant according to claim 3, characterized in that: In step S1, the mass ratio of 8-hydroxyquinoline-2-carboxaldehyde to polyetheramine is 0.5-0.8:

1.

5. The sealant according to claim 3, characterized in that: In step S2, the mass ratio of montmorillonite, hexadecyltrimethylammonium bromide, and KH560 is 10:3-7:0.1-0.

5.

6. The sealant according to claim 3, characterized in that: In step S3, the mass ratio of pretreated montmorillonite to Schiff base intermediate is 10:2-5.

7. The sealant according to claim 1, characterized in that: The silane coupling agent is at least one of A-1120, KH550, and KH560.

8. The sealant according to claim 1, characterized in that: The plasticizer is dibutyl phthalate; the dehydrating agent is vinyltris(β-methoxyethoxy)silane.

9. The sealant according to claim 1, characterized in that: The catalyst is dibutyltin diacetate.

10. A method for preparing the sealant according to claims 1-9, characterized in that, The process includes the following steps: mixing silane-terminated polyether resin, modified filler, silane coupling agent, catalyst, plasticizer, and dehydrating agent evenly, then degassing, discharging, and sealing to obtain a high-performance silane-terminated polyether sealant.

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