Oxygen-containing small-molecule intercalated hydrotalcite and rubber composite material, and preparation method and application of oxygen-containing small-molecule intercalated hydrotalcite and rubber composite material

Abstract

The invention provides an oxygen-containing small-molecule intercalated hydrotalcite, a rubber composite material, and a preparation method and application of the oxygen-containing small-molecule intercalated hydrotalcite and rubber composite material. The oxygen-containing small molecule intercalated hydrotalcite is obtained by mixing and reacting components including ethanol salt, methoxide and a solvent; the ethanol salt comprises divalent ethanol salt and trivalent ethanol salt; the rubber composite material is prepared from the following components: rubber, oxygen-containing small molecule intercalated hydrotalcite and a vulcanizing agent. The oxygen-containing micromolecule intercalated hydrotalcite prepared by the method has larger interlayer spacing and better dispersity in a rubber matrix, interlayer water can be removed at the temperature of 100 DEG C or below, the influence in the vulcanization process is avoided, and the oxygen-containing micromolecule intercalated hydrotalcite is suitable for a high-temperature vulcanization environment, is used in a rubber composite material and can improve the gas barrier property of the composite material.

Description

Technical Field

[0001] This invention relates to the field of rubber composite materials technology, and more specifically, to an oxygen-containing small molecule intercalated hydrotalcite, a rubber composite material, its preparation method, and its application. Background Art

[0002] Butyl rubber inherently possesses excellent gas barrier properties, while brominated butyl rubber, while maintaining this characteristic, further enhances its barrier effect against gases such as oxygen and nitrogen, as well as water vapor, thus becoming the preferred material for tire inner linings and sealing applications. Compared to traditional spherical fillers (such as carbon black and silica), the use of layered nanofillers (such as montmorillonite, kaolin, and layered bilayer metal hydroxides) provides a new approach to enhancing the gas barrier properties of butyl rubber. These layered fillers can form a special nanoscale network structure within the rubber matrix, which not only significantly improves the material's mechanical properties but also endows it with unique functional characteristics.

[0003] Layered double hydroxides (LDHs) are a class of bimetallic hydroxides with tunable structures. Due to their flexible chemical composition, simple synthesis, and low cost, they have attracted considerable attention in the field of functional materials in recent years. However, in the tire industry, the demand for high-airtightness inner liner materials remains unmet, while the ultra-high airtightness requirements of special rubbers in the aerospace field pose a severe challenge to existing technologies.

[0004] Currently, the common methods for synthesizing hydrotalcite involve: divalent metal salts such as magnesium, zinc, nickel, and cobalt salts (e.g., magnesium nitrate, magnesium chloride, zinc sulfate); trivalent metal salts such as aluminum, iron, and chromium salts (e.g., aluminum nitrate, aluminum chloride); alkaline solutions such as sodium hydroxide or sodium carbonate to adjust the pH and form a layered structure; and anion sources such as carbonate, nitrate, and chloride ions embedded in the interlayer. This synthesis method results in the presence of interlayer water, and the carbonate ions readily insert into the layers. The interaction between water and carbonate ions is particularly strong, making it impossible to remove the interlayer water, which severely impacts the sulfidation process.

[0005] In existing hydrotalcite technology, the interlayer spaces are primarily composed of water molecules, which significantly impacts the performance of rubber composites during vulcanization. Furthermore, the small interlayer spacing makes hydrotalcite prone to agglomeration when added to rubber groups, affecting the overall performance of the composite. Therefore, it is necessary to research a hydrotalcite with a larger interlayer spacing and to replace the water molecules in the interlayer spaces with other small molecules. This would eliminate the influence of interlayer water on vulcanization and, with a larger interlayer spacing, solve the problem of hydrotalcite agglomeration in the rubber matrix. Summary of the Invention

[0006] In order to solve the technical problems existing in the prior art, the present invention provides an oxygen-containing small molecule intercalated hydrotalcite, a rubber composite material, a preparation method thereof, and its application.

[0007] This invention uses oxygen-containing small molecules to replace traditional interlayer water molecules to perform intercalation modification of hydrotalcite (LDH), and achieves precise control of the interlayer structure through molecular design. Specifically, the effects are as follows: oxygen-containing small molecules (such as polyols and carboxylic acid compounds) form a novel hydrogen bond coordination mode with the hydroxyl groups of LDH layers through their active functional groups such as -OH and -COOH, and construct a three-dimensional cross-linked network with interlayer anions, significantly increasing the interlayer spacing (XRD confirmed to increase it by 20-50%), reducing aggregation, and allowing rubber molecular chains to enter between the layers, resulting in more uniform dispersion and superior performance; enhanced high-temperature stability: the novel hydrogen bond network weakens the binding energy between traditional water molecules and the layers, reducing the interlayer water desorption temperature by 60-150℃ (TGA confirmed), allowing interlayer water to be desorbed below 100℃, avoiding the impact during the vulcanization process, and making it suitable for high-temperature vulcanization environments; the directional arrangement of two-dimensional nanosheets forms a "maze effect," resulting in a larger interlayer spacing of the hydrotalcite prepared in this invention, better dispersion in the rubber matrix, and a 20-40% reduction in gas permeability compared to rubber composites with existing magnesium-aluminum hydrotalcite, achieving better technical results.

[0008] The oxygen-containing small molecules of the present invention have the potential to construct hydrogen bond networks in the interlayer. They can not only participate in the formation of hydrogen bond networks, but also serve as solvation shell components for charge-compensating anions. The interlayer domains of hydrotalcite (LDH) provide a unique confined environment for oxygen-containing small molecules, enabling them to form ordered supramolecular structures through hydrogen bonding. Based on this, effective intercalation modification of hydrotalcite can be achieved.

[0009] This invention solves the problems of hydrotalcite's tendency to agglomerate and become poorly dispersed in rubber, as well as its poor thermal stability and permeability coefficient. When used in rubber composites, it can improve the gas barrier properties of the composites.

[0010] One objective of this invention is to provide an oxygen-containing small molecule intercalated hydrotalcite, which is obtained by mixing and reacting components including ethanol salts, methanol salts, and solvents; the ethanol salts include divalent ethanol salts and trivalent ethanol salts.

[0011] In a preferred embodiment of the present invention, The divalent ethoxide is at least one selected from magnesium ethoxide, calcium ethoxide, zinc ethoxide, cobalt ethoxide, copper ethoxide, and nickel ethoxide; and / or, The trivalent ethoxide is at least one of aluminum ethoxide, chromium ethoxide, and iron ethoxide; and / or... The methoxide is at least one selected from sodium methoxide, potassium methoxide, magnesium methoxide, and aluminum methoxide; and / or, The solvent is at least one of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, butanol, formic acid, diacetic acid, and dimethyl sulfoxide.

[0012] A second objective of this invention is to provide a method for preparing oxygen-containing small molecule intercalated hydrotalcite, the method comprising: The oxygen-containing small molecule intercalated hydrotalcite is obtained by mixing and reacting components including ethanol salts, methanol salts, and solvents; the ethanol salts include divalent ethanol salts and trivalent ethanol salts; the solvents include solvent A and solvent B.

[0013] In a preferred embodiment of the present invention, The method includes the following steps: (1) Mix the ethanol salt with solvent A to obtain mixture A; (2) Mix the methanol salt with solvent B to obtain mixture B; (3) Add the mixture A obtained in step (1) to the mixture B obtained in step (2) to react and obtain the oxygen-containing small molecule intercalated hydrotalcite.

[0014] In a preferred embodiment of the present invention, Step (1), The divalent ethoxide is at least one selected from magnesium ethoxide, calcium ethoxide, zinc ethoxide, cobalt ethoxide, copper ethoxide, and nickel ethoxide; and / or, The trivalent ethoxide is at least one of aluminum ethoxide, chromium ethoxide, and iron ethoxide; and / or... Solvent A is at least one selected from methanol, ethanol, ethylene glycol, n-propanol, isopropanol, butanol, formic acid, diacetic acid, and dimethyl sulfoxide; and / or, Mixing is carried out under stirring until homogeneous; and / or, The ratio of ethanol salt to solvent A is 1 mol : (50~2000) ml, preferably 1 mol : (200~1500) ml; and / or, In the ethanolate, the molar ratio of divalent ethanolate to trivalent ethanolate is 1:(0.1~10), preferably 1:(0.1~2). The molar ratio of divalent ethanolate to trivalent ethanolate can preferably be within the range of any two ratios above, such as 1:0.1, 1:0.2, 1:0.3, 1:0.5, 1:0.8, 1:1, 1:1.5, 1:2, or 1:(0.1~0.5); and / or... Step (2), The methoxide is at least one selected from sodium methoxide, potassium methoxide, magnesium methoxide, and aluminum methoxide; and / or, Solvent B is at least one selected from methanol, ethanol, ethylene glycol, n-propanol, isopropanol, formic acid, and dimethyl sulfoxide; and / or Mixing is carried out under stirring until homogeneous; and / or, The ratio of methacrylate to solvent B is 1 mol : (500~20000) ml. This ratio can be 1 mol : 500 ml, 1 mol : 1000 ml, 1 mol : 2000 ml, 1 mol : 5000 ml, 1 mol : 10000 ml, 1 mol : 12000 ml, 1 mol : 15000 ml, 1 mol : 20000 ml, or any two of these ratios within a range, for example, 1 mol : (5000~15000) ml; and / or, Step (3), The reaction is carried out under stirring at a speed of 200-600 rpm; and / or, The molar ratio of ethanolate to methanolate is (1~100):1, preferably (5~40):1; and / or, Mixture A is added dropwise to mixture B at a rate of 10-100 ml / min; and / or, The reaction temperature is 30~90℃; and / or, The reaction time is 16-48 hours; and / or, The product after the reaction is post-processed, preferably including filtration, washing, and drying.

[0015] If the product suspension obtained from the reaction is filtered in a vacuum filtration flask, washed with anhydrous ethanol and dried (12~36 hours, 50~80℃), the white powder after drying is the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM-LDH).

[0016] A third objective of this invention is to provide an application of the above-mentioned oxygen-containing small molecule intercalated hydrotalcite or the oxygen-containing small molecule intercalated hydrotalcite obtained by the above-mentioned preparation method in rubber composite materials.

[0017] The fourth objective of this invention is to provide a rubber composite material, which is made from components including rubber, oxygen-containing small molecule intercalated hydrotalcite, and a vulcanizing agent; wherein the oxygen-containing small molecule intercalated hydrotalcite is obtained by the preparation method described above or as described in 2 above.

[0018] In a preferred embodiment of the present invention, The rubber is at least one of butyl rubber and halogenated butyl rubber; the halogenated butyl rubber is at least one of chlorinated butyl rubber, brominated butyl rubber, and fluorinated butyl rubber; and / or... The vulcanizing agent may be a vulcanizing agent of existing technology, preferably sulfur; and / or, The rubber composite material comprises, based on 100 parts by weight of rubber: 100 parts by weight of rubber; 2-20 parts by weight of oxygen-containing small molecule intercalated hydrotalcite; preferably 5-20 parts by weight. Vulcanizing agent: 0.5-4 parts by weight; preferably 1.5-3.5 parts by weight; Optionally, the rubber composite material further includes fillers, antioxidants, and activators, and based on 100 parts by weight of rubber, the rubber composite material comprises: 5-100 parts by weight of filler; preferably 10-50 parts by weight; Anti-aging agent: 0.5-4 parts by weight; preferably 1-3 parts by weight; 1-25 parts by weight of activator; preferably 2-8 parts by weight.

[0019] The addition of fillers, antioxidants, and activators provides better mechanical properties and aging resistance to rubber composites, and can also be considered as preferred components.

[0020] The filler may be a commonly used filler in the prior art, preferably at least one of carbon black and silica; and / or, The antioxidant can be a filler commonly used in existing technologies, such as antioxidant 4010NA, antioxidant RD, antioxidant 4020, etc.; and / or, The active agent is at least one selected from stearic acid, zinc oxide, magnesium oxide, triethanolamine, and rare earth compounds; and / or, The rubber composite material may also include commonly used rubber additives in the prior art, such as accelerators and plasticizers. Accelerators include accelerator DM, and plasticizers include paraffin oil and naphthenic oil. The dosage is also the conventional dosage in the prior art.

[0021] The fifth objective of this invention is to provide a method for preparing a rubber composite material, the method comprising: The components, including rubber, oxygen-containing small molecule intercalated hydrotalcite, and a vulcanization system, are mixed evenly and then vulcanized to obtain the rubber composite material; optionally, the components also include fillers, antioxidants, and antioxidants. Preferably, the vulcanization temperature is 145~210℃, more preferably 150~200℃.

[0022] After mixing thoroughly, it is best to let it stand for 24-48 hours before vulcanization.

[0023] The mixing equipment can be existing conventional equipment, such as open mills, internal mixers, etc., or a combination thereof.

[0024] The sixth objective of this invention is to provide an application of the above-mentioned rubber composite material or the rubber composite material obtained by the above-mentioned preparation method in airtight materials, preferably in the airtight layer of a tire.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses oxygen-containing small molecules to replace traditional interlayer water molecules to perform intercalation modification of hydrotalcite (LDH), and achieves precise control of the interlayer structure through molecular design. Specifically, the effects are as follows: oxygen-containing small molecules (such as polyols and carboxylic acid compounds) form a novel hydrogen bond coordination mode with the hydroxyl groups of LDH layers through their active functional groups such as -OH and -COOH, and construct a three-dimensional cross-linked network with interlayer anions, significantly increasing the interlayer spacing (XRD confirmed to increase it by 20-50%), reducing aggregation, and allowing rubber molecular chains to enter between the layers, resulting in more uniform dispersion and superior performance; enhanced high-temperature stability: the novel hydrogen bond network weakens the binding energy between traditional water molecules and the layers, reducing the interlayer water desorption temperature by 60-150℃ (TGA confirmed), allowing interlayer water to be desorbed below 100℃, avoiding the impact during the vulcanization process, and making it suitable for high-temperature vulcanization environments; the directional arrangement of two-dimensional nanosheets forms a "maze effect," resulting in a larger interlayer spacing of the hydrotalcite prepared in this invention, better dispersion in the rubber matrix, and a 20-40% reduction in gas permeability compared to rubber composites with existing magnesium-aluminum hydrotalcite, achieving better technical results.

[0026] The oxygen-containing small molecules of the present invention have the potential to construct hydrogen bond networks in the interlayer. They can not only participate in the formation of hydrogen bond networks, but also serve as solvation shell components for charge-compensating anions. The interlayer domains of hydrotalcite (LDH) provide a unique confined environment for oxygen-containing small molecules, enabling them to form ordered supramolecular structures through hydrogen bonding. Based on this, effective intercalation modification of hydrotalcite can be achieved.

[0027] This invention solves the problems of hydrotalcite's tendency to agglomerate and become poorly dispersed in rubber, as well as its poor thermal stability and permeability coefficient. When used in rubber composites, it can improve the gas barrier properties of the composites. Attached Figure Description

[0028] Figure 1 A schematic diagram of the structure of magnesium aluminum hydrotalcite in the prior art; Figure 2 XRD patterns of the oxygen-containing small molecule hydrotalcite prepared in Example 4 and the magnesium aluminum hydrotalcite of the prior art; Figure 3 The XRD pattern of the oxygen-containing small molecule hydrotalcite prepared in Example 4 is shown below. Figure 2 Magnified XRD pattern of the oxygen-containing small molecule hydrotalcite prepared in Example 4; Figure 4(a) is a transmission electron microscope image of magnesium aluminum hydrotalcite in the prior art; Figure 4(b) is a partial enlarged transmission electron microscope image of magnesium aluminum hydrotalcite in the prior art; Figure 4(c) Transmission electron microscopy image of the oxygen-containing small molecule hydrotalcite prepared in Example 4; Figure 4(d) is a partial magnified transmission electron microscope image of the oxygen-containing small molecule hydrotalcite prepared in Example 4; Figure 5 The thermogravimetric analysis diagram shows the oxygen-containing small molecule hydrotalcite prepared in Example 3 and the magnesium-aluminum hydrotalcite of the prior art. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0030] All raw materials used in the examples are commercially available.

[0031] The hydrotalcite used for comparison is commercially available magnesium aluminum hydrotalcite from McLean.

[0032] The test standard for gas permeability coefficient is GB1038-2000.

[0033] The parts in the examples and comparative examples refer to parts by weight.

[0034] Example 1 0.8 mol of divalent magnesium ethoxide and 0.4 mol of trivalent aluminum ethoxide were simultaneously added to a three-necked flask containing 800 mL of methanol and stirred at a constant temperature of 30°C and 300 rpm for 24 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting ethoxide suspension was added dropwise to a methanol solution of sodium methoxide at a rate of 10 mL / min, and stirred at 30°C and 300 rpm for 24 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60°C). The dried white powder is the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM1-LDH).

[0035] 100 parts of brominated butyl rubber, 10 parts of OM1-LDH, 2 parts of stearic acid, 2 parts of zinc oxide, 2 parts of antioxidant 4020, 40 parts of carbon black N330, and 2.5 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 24 hours for later use.

[0036] The prepared OM-LDH / BIIR compound was vulcanized at 150°C to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0037] Example 2 0.96 mol of nickel ethoxide and 0.48 mol of iron ethoxide were simultaneously added to a three-necked flask containing 800 mL of methanol and stirred at a constant temperature of 90 °C and 300 rpm for 16 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting ethoxide suspension was added dropwise to a methanol solution of sodium methoxide at a rate of 10 mL / min, and stirred at 90 °C and 300 rpm for 24 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder is the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM2-LDH).

[0038] 100 parts of brominated butyl rubber, 15 parts of OM2-LDH, 2 parts of stearic acid, 1.5 parts of antioxidant RD, 35 parts of carbon black N330, and 3 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 36 hours for later use.

[0039] The prepared OM-LDH / BIIR compound was vulcanized at 160℃ to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0040] Example 3 0.64 mol of cobalt ethoxide and 0.32 mol of chromium ethoxide were simultaneously added to a three-necked flask containing 800 mL of dimethyl sulfoxide (DMSO) and stirred at a constant temperature of 60 °C and 300 rpm for 24 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting suspension of metallic ethanol was added dropwise to the methanol solution of sodium methoxide at a rate of 100 mL / min, and stirred at 60 °C and 300 rpm for 16 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder was the synthesized oxygen-containing small-molecule intercalated hydrotalcite (OM3-LDH).

[0041] 100 parts of brominated butyl rubber, 5 parts of OM3-LDH, 2 parts of stearic acid, 2 parts of zinc oxide, 1 part of antioxidant 4010NA, 20 parts of carbon black N330, and 1.5 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 48 hours for later use.

[0042] Step 3: The prepared OM-LDH / BIIR compound is vulcanized at 170℃ to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0043] Example 4 1.2 mol of zinc ethoxide and 2.4 mol of aluminum ethoxide were simultaneously added to a three-necked flask containing 800 ml of ethanol and stirred at a constant temperature of 60 °C and 300 rpm for 48 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 ml of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting suspension of metallic ethanol was added dropwise to a methanol solution of sodium methoxide at a rate of 60 ml / min, and stirred at 60 °C and 300 rpm for 24 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder was the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM4-LDH).

[0044] 100 parts of brominated butyl rubber, 20 parts of OM4-LDH, 2 parts of stearic acid, 3 parts of zinc oxide, 2 parts of antioxidant 4020, 50 parts of carbon black N660, and 3.5 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 24 hours for later use.

[0045] The prepared OM-LDH / BIIR compound was vulcanized at 160℃ to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0046] Example 5 0.72 mol copper ethoxide and 0.36 mol chromium ethoxide were simultaneously added to a three-necked flask containing 800 mL of butanol and stirred at a constant temperature of 60 °C and 300 rpm for 24 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting suspension of metallic ethanol was added dropwise to a methanol solution of sodium methoxide at a rate of 30 mL / min, and stirred at 60 °C and 300 rpm for 48 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder was the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM5-LDH).

[0047] 100 parts of brominated butyl rubber, 12 parts of OM5-LDH, 2 parts of stearic acid, 3 parts of zinc oxide, 1 part of antioxidant RD, 15 parts of carbon black N660, and 3.5 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 24 hours for later use.

[0048] The prepared OM-LDH / BIIR compound was vulcanized at 180°C to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0049] Example 6 2.4 mol of calcium ethoxide and 0.24 mol of aluminum ethoxide were simultaneously added to a three-necked flask containing 800 mL of methanol and stirred at a constant temperature of 80 °C and 300 rpm for 36 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting suspension of metallic ethanol was added dropwise to the methanol solution of sodium methoxide at a rate of 10 mL / min, and stirred at 80 °C and 300 rpm for 24 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder was the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM6-LDH).

[0050] 100 parts of brominated butyl rubber, 8 parts of OM6-LDH, 2 parts of stearic acid, 3 parts of zinc oxide, 1.5 parts of antioxidant RD, 50 parts of carbon black N300, and 2.5 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 36 hours for later use.

[0051] The prepared OM-LDH / BIIR compound was vulcanized at 170℃ to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0052] Example 7 1.6 mol of ferric ethoxide and 0.72 mol of magnesium ethoxide were simultaneously added to a three-necked flask containing 800 mL of ethanol and stirred at a constant temperature of 90 °C and 300 rpm for 24 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting suspension of metallic ethanol was added dropwise to a methanol solution of sodium methoxide at a rate of 10 mL / min, and stirred at 90 °C and 300 rpm for 24 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder was the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM7-LDH).

[0053] 100 parts of brominated butyl rubber, 25 parts of OM7-LDH, 3 parts of stearic acid, 3 parts of magnesium oxide, 1.5 parts of antioxidant 4020, 30 parts of carbon black N330, and 2.5 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 24 hours for later use.

[0054] The prepared OM-LDH / BIIR compound was vulcanized at 190℃ to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0055] Example 8 0.40 mol manganese ethoxide and 0.20 mol aluminum ethoxide were simultaneously added to a three-necked flask containing 800 mL of methanol and stirred at a constant temperature of 60 °C and 300 rpm for 48 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol and stirred at room temperature and 300 rpm for 5 min. The resulting suspension of metallic ethanol was added dropwise to a methanol solution of sodium methoxide at a rate of 10 mL / min, and stirred at 60 °C and 300 rpm for 24 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder was the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM8-LDH).

[0056] 100 parts of brominated butyl rubber, 18 parts of OM8-LDH, 3 parts of stearic acid, 2 parts of magnesium oxide, 1 part of antioxidant RD, 25 parts of carbon black N660, and 2.5 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 48 hours for later use.

[0057] The prepared OM-LDH / BIIR compound was vulcanized at 180°C to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0058] Example 9 0.56 mol magnesium ethoxide and 0.28 mol aluminum ethoxide were simultaneously added to a three-necked flask containing 800 mL of diacetic acid, and stirred at a constant temperature of 80 °C and 300 rpm for 24 h. 5 g of sodium methoxide was added to a 3 L three-necked flask containing 1000 mL of methanol, and stirred at room temperature and 300 rpm for 5 min. The resulting suspension of metallic ethanol was added dropwise to the methanol solution of sodium methoxide at a rate of 10 mL / min, and stirred at 80 °C and 300 rpm for 24 h. The resulting suspension was filtered in a vacuum filtration flask, washed with anhydrous ethanol, and dried (24 h, 60 °C). The dried white powder was the synthesized oxygen-containing small molecule intercalated hydrotalcite (OM9-LDH).

[0059] 100 parts of brominated butyl rubber, 7 parts of OM9-LDH, 3 parts of stearic acid, 5 parts of zinc oxide, 1.5 parts of antioxidant 4020, 10 parts of carbon black N660, and 2.0 parts of sulfur are compounded in a kneader. All fillers are mixed evenly and left to stand for 24 hours for later use.

[0060] The prepared OM-LDH / BIIR compound was vulcanized at 180°C to prepare a hydrotalcite rubber composite material with high dispersibility and excellent gas barrier properties.

[0061] Comparative Example 1 The difference from Example 1 is that the oxygen-containing small molecule intercalated hydrotalcite was replaced with an equal mass of magnesium aluminum hydrotalcite; wherein the magnesium aluminum hydrotalcite was purchased from Maclean, CAS number 11097-59-9, chemical formula Mg6Al2(CO3)(OH). 16 • 4H2O, with a molecular weight of 603.98.

[0062] Except for the differences mentioned above, all other conditions in Comparative Example 1 were the same as in Example 1, resulting in a rubber composite material.

[0063] Table 1. Gas permeability coefficient test results of the composite materials prepared in Examples 1-9 and Comparative Example 1.

[0064] Note: Gas permeability coefficient testing was conducted according to GB / 1038–2000.

[0065] As shown in Table 1, compared with Comparative Example 1, the gas permeability coefficient of the rubber composite material prepared in Example 1 was reduced by 29.8%. This demonstrates that brominated butyl rubber with added oxygen-containing small molecule intercalated hydrotalcite has superior gas barrier properties compared to commercially available magnesium aluminum hydrotalcite. Figure 1 This is a schematic diagram of the structure of a traditional hydrotalcite, specifically a commercially available magnesium-aluminum hydrotalcite. Figure 1 It is known that the interlayer of traditional hydrotalcite consists of water molecules and carbonate ions, while the interlayer of this invention consists of polyols or carboxylic acid compounds, with active functional groups such as -OH and -COOH forming a novel hydrogen bond coordination mode with the hydroxyl groups of the LDH layer.

[0066] Figures 2-3 The XRD patterns are of the oxygen-containing small molecule hydrotalcite prepared in Example 4 and commercially available magnesium-aluminum hydrotalcite. Figures 2-3 It can be seen that the characteristic peak of (003) moved from 11.72° to 10.1°, which represents that the interlayer spacing increased from 0.76nm to 0.88nm, proving that the small molecule obtained in Example 4 showed a larger interlayer spacing in XRD, which increased from 0.76nm to 0.88nm.

[0067] Figures 4(a) and 4(b) are transmission electron micrographs of commercially available magnesium aluminum hydrotalcite, and Figures 4(c) and 4(d) are transmission electron micrographs of hydrotalcite prepared in Example 4. As can be seen from the figures, compared with Comparative Example 1, the lamellar width of Example 4 is larger and the overlap is less, which proves that the aggregation phenomenon is significantly improved.

[0068] Figure 5 This is a thermogravimetric comparison diagram of the oxygen-containing small molecule hydrotalcite prepared in Example 3 and commercially available magnesium-aluminum hydrotalcite. Figure 5It can be seen that the thermogravimetric behavior and thermal decomposition mechanism of the oxygen-containing small molecule hydrotalcite prepared in Example 3 are different from those of commercially available magnesium-aluminum hydrotalcite. For the commercially available magnesium-aluminum hydrotalcite system, its thermal decomposition process exhibits a typical three-stage characteristic: the first stage (100~250℃) is mainly characterized by the removal of interlayer water, reaching the maximum weight loss rate at 230℃, with a mass loss of about 15%; the second stage (250~350℃) involves the reconstruction of the lamellar structure, with the bimetallic hydroxide dehydrating to form a layered bimetallic oxide, accompanied by the decomposition of interlayer carbonate ions releasing carbon dioxide; the third stage (350~500℃) involves a fundamental transformation of the crystal structure, with the lamellar structure undergoing continuous dehydration and forming a spinel-type metal oxide composite structure through topological transformation.

[0069] The novel propanol-intercalated hydrotalcite prepared in Example 3 exhibited significantly different thermal behavior. Its decomposition process can be divided into two typical stages: the first stage (100-220℃) reaches its maximum weight loss rate at 102℃, corresponding to the rapid desorption of propanol molecules from the interlayer, with a mass loss of approximately 15%; the second stage (200-500℃) shows a wide temperature range decomposition characteristic, with a maximum weight loss peak (34%) at 405℃. This process includes the dehydroxylation reaction of the metal hydroxyl layers and the synergistic decomposition of sodium methoxide anions in the interlayer. Thermogravimetric analysis (TGA) curves show that the organically modified hydrotalcite system has a significantly advanced thermal decomposition onset temperature, a characteristic stemming from the weak hydrogen bonding between the small interlayer alcohol molecules and the interlayer layers.

[0070] Thermogravimetric analysis proved that the novel hydrogen bond network weakens the binding energy between traditional water molecules and the layers, reducing the desorption temperature of interlayer water by 60-150℃. Interlayer water can be removed below 100℃, avoiding its impact on the sulfidation process and making it suitable for high-temperature sulfidation environments.

[0071] The gas permeability coefficient of the rubber composite materials obtained from the oxygen-containing small molecule hydrotalcites prepared in Examples 1-9 for It has good gas barrier properties and achieves good technical results.

Claims

1. An oxygen-containing small molecule intercalated hydrotalcite, obtained by mixing and reacting components including ethanol salts, methanol salts, and solvents; wherein the ethanol salts include divalent ethanol salts and trivalent ethanol salts.

2. The oxygen-containing small molecule intercalated hydrotalcite as described in claim 1, characterized in that: The divalent ethoxide is at least one selected from magnesium ethoxide, calcium ethoxide, zinc ethoxide, cobalt ethoxide, copper ethoxide, and nickel ethoxide; and / or, The trivalent ethoxide is at least one of aluminum ethoxide, chromium ethoxide, and iron ethoxide; and / or... The methoxide is at least one selected from sodium methoxide, potassium methoxide, magnesium methoxide, and aluminum methoxide; and / or, The solvent is at least one of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, butanol, formic acid, diacetic acid, and dimethyl sulfoxide.

3. A method for preparing oxygen-containing small molecule intercalated hydrotalcite as described in claim 1 or 2, the method comprising: The oxygen-containing small molecule intercalated hydrotalcite is obtained by mixing and reacting components including ethanol salts, methanol salts, and solvents; the ethanol salts include divalent ethanol salts and trivalent ethanol salts; the solvents include solvent A and solvent B.

4. The preparation method of oxygen-containing small molecule intercalated hydrotalcite as described in claim 3, characterized in that, The method includes the following steps: (1) Mix the ethanol salt with solvent A to obtain mixture A; (2) Mix the methanol salt with solvent B to obtain mixture B; (3) Add the mixture A obtained in step (1) to the mixture B obtained in step (2) to react and obtain the oxygen-containing small molecule intercalated hydrotalcite.

5. The method for preparing oxygen-containing small molecule intercalated hydrotalcite as described in claim 4, characterized in that: Step (1), The divalent ethoxide is at least one selected from magnesium ethoxide, calcium ethoxide, zinc ethoxide, cobalt ethoxide, copper ethoxide, and nickel ethoxide; and / or, The trivalent ethoxide is at least one of aluminum ethoxide, chromium ethoxide, and iron ethoxide; and / or... Solvent A is at least one selected from methanol, ethanol, ethylene glycol, n-propanol, isopropanol, butanol, formic acid, diacetic acid, and dimethyl sulfoxide; and / or, Mixing is carried out under stirring until homogeneous; and / or, The ratio of ethoxide to solvent A is 1 mol : (50~2000) ml; and / or, In ethanolates, the molar ratio of divalent ethanolate to trivalent ethanolate is 1:(0.1~10); and / or, Step (2), The methoxide is at least one selected from sodium methoxide, potassium methoxide, magnesium methoxide, and aluminum methoxide; and / or, Solvent B is at least one selected from methanol, ethanol, ethylene glycol, n-propanol, isopropanol, formic acid, and dimethyl sulfoxide; and / or, Mixing is carried out under stirring until homogeneous; and / or, The ratio of methanol salt to solvent B is 1 mol : (500~20000) ml; and / or, Step (3), The reaction is carried out under stirring at a speed of 200-600 rpm; and / or, The molar ratio of ethanolate to methanolate is (1~100):1; and / or, Mixture A is added dropwise to mixture B at a rate of 10-100 ml / min; and / or, The reaction temperature is 30~90℃; and / or, The reaction time is 16-48 hours; and / or, The products after the reaction were post-processed.

6. The application of an oxygen-containing small molecule intercalated hydrotalcite as described in claim 1 or 2, or an oxygen-containing small molecule intercalated hydrotalcite prepared by any one of claims 3 to 5, in rubber composite materials.

7. A rubber composite material, comprising components including rubber, oxygen-containing small molecule intercalated hydrotalcite, and a vulcanizing agent; wherein the oxygen-containing small molecule intercalated hydrotalcite is as described in claim 1 or 2 or prepared by any one of claims 3 to 5.

8. The rubber composite material as described in claim 8, characterized in that: The rubber is at least one of butyl rubber and halogenated butyl rubber; the halogenated butyl rubber is at least one of chlorinated butyl rubber, brominated butyl rubber, and fluorinated butyl rubber; and / or... The rubber composite material comprises, based on 100 parts by weight of rubber: 100 parts by weight of rubber; 2-20 parts by weight of oxygen-containing small molecule intercalated hydrotalcite; Vulcanizing agent: 0.5 to 4 parts by weight.

9. A method for preparing a rubber composite material as described in claim 7 or 8, the method comprising: The rubber composite material is obtained by uniformly mixing and vulcanizing the components, including rubber, oxygen-containing small molecule intercalated hydrotalcite, and vulcanizing agent.

10. The application of a rubber composite material as described in claim 7 or 8, or a rubber composite material obtained by the preparation method as described in claim 9, in an airtight material.

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