A hyperbranched silicone-modified high-strength polyether ablative-resistant elastomer and a preparation method thereof

Abstract

The application discloses a kind of hyperbranched organosilicon modified high-strength polyether type ablative-resistant elastomers and preparation method thereof.The elastomer includes A component and B component, the mass percentage of A component and B component is 10~90%:90~10%;The raw materials of A component mainly include hyperbranched organosilicon resin and catalyst;The raw materials of B component mainly include silane end-capped polyether;A, B component can also include filler.The application can obtain the organosilicon elastomer by mixing and stirring silane end-capped polyether and hyperbranched organosilicon resin according to proportion, solidification.The elastomer of the application uses hyperbranched organosilicon resin as hard segment, and silane end-capped polyether as soft segment, which exhibits excellent high-temperature resistance, ablative resistance, strong adhesion, excellent tear strength, excellent tensile strength and good elongation at break;Its preparation method is simple, low in cost, and suitable for large-scale application.

Description

Technical Field

[0001] This invention relates to an elastomer and its preparation method, and more particularly to a hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer and its preparation method. Background Technology

[0002] The unique properties of siloxane bonds give organosilicon materials distinctive thermodynamic properties. Compared to homologous carbon-based polymers, organosilicon polymers typically exhibit better flexibility and ductility. Furthermore, the silicon-oxygen bond energy in organosilicon polymers reaches as high as 443 kJ / mol, thus granting them excellent heat resistance, making them the most widely used resin matrix in ablation-resistant heat-protective coatings. Among various organosilicon polymers, organosilicon elastomers are a novel type of organosilicon elastomer material, typically composed of linear polysiloxanes and three-dimensional organosilicon resins. Their unique three-dimensional structure, with alternating soft and hard segments, endows them with excellent temperature resistance, ablation resistance, and mechanical properties. In summary, organosilicon elastomers, as resin matrices for ablation-resistant heat-protective coatings, have a very broad application prospect due to their convenient application and excellent performance.

[0003] However, the inherent defects of silicone elastomers have consistently limited their application in the field of ablation heat protection. First, the lack of intermolecular forces in silicone polymers results in poor mechanical properties, particularly tear resistance and tensile strength, which fail to meet practical requirements. Second, silicone polymers typically have high viscosity, making application difficult and requiring the addition of large amounts of solvents for dilution to mitigate this challenge. Finally, the low surface energy and lack of carbon-based segments in traditional silicone polymers lead to poor ablation thermal efficiency, resulting in poor surface adhesion, inadequate thermal protection, and high back temperatures in practical applications. These defects restrict the further development of silicone polymers in ablation heat protection materials and limit their application scenarios.

[0004] To address the above issues, patent CN117402586A uses petroleum ether as a solvent and tetraethyl orthosilicate as a surface treatment agent to treat the surfaces to be bonded, achieving stable adhesion of the silicone rubber heat-resistant coating under high and low temperature environments. This improves the adhesion between the primer and the silicone rubber heat-resistant coating. However, the introduction of the surface treatment agent increases the application steps of the silicone heat-resistant coating, prolonging the application time. Furthermore, the introduction of the solvent further increases environmental pressure and the difficulty of applying heat-resistant coatings to large components, further limiting the application of silicone heat-resistant coatings. Patent CN117844374A introduces MQ resin powder as a hard segment structure into traditional silicone rubber heat-resistant coatings, thereby modifying a matrix with low cost, excellent thermal stability, and high ablation heat protection efficiency, improving the shear resistance of the heat-resistant coating. However, the introduction of powdered silicone resin significantly increases the viscosity of the silicone heat-resistant coating, leading to difficulties in application and high equipment failure rates during spraying. Meanwhile, the introduction of MQ resin can also lead to problems such as reduced elongation at break and decreased coating flexibility, making it difficult to be an optimal solution for improving traditional organosilicon materials.

[0005] In summary, current research on the modification of organosilicon materials in terms of heat protection and adhesion is relatively limited. Improving the mechanical properties, adhesion, and thermal protection performance of organosilicon heat-resistant materials without increasing the complexity of construction remains a significant challenge. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer with excellent adhesion and ablation resistance and temperature resistance.

[0007] The second objective of this invention is to provide a method for preparing the above-mentioned hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer.

[0008] Technical solution: The hyperbranched organosilicon-modified high-strength polyether ablation-resistant elastomer of the present invention comprises component A and component B, wherein the mass percentage of component A and component B is 10-90%: 90-10%.

[0009] Component A comprises the following raw materials in parts by weight: hyperbranched silicone resin: 100-25 parts; catalyst: 0-5 parts, excluding 0; flame retardant filler: 0-70 parts; ablation resistant filler: 0-70 parts; reinforcing filler: 0-70 parts.

[0010] Component B comprises the following raw materials in parts by weight: silane-terminated polyether: 100-25 parts; catalyst: 0-5 parts; flame-retardant filler: 0-70 parts; ablation-resistant filler: 0-70 parts; reinforcing filler: 0-70 parts.

[0011] The structural formula of the hyperbranched organosilicon resin is as follows:

[0012]

[0013] Wherein, R is one or more combinations of methyl, phenyl, vinyl, chloromethyl, and glycidyl ether propyl, and R′ is methyl. Hyperbranched silicone resin, as a hard segment component, improves the material's temperature resistance and ablation resistance on the one hand, and serves as a crosslinking site to increase the degree of crosslinking in the material system, thereby enhancing the material's mechanical properties on the other.

[0014] Preferably, R in the hyperbranched organosilicon resin is phenyl, and R′ is methyl, and its structural formula is:

[0015]

[0016] This type of hyperbranched silicone resin is combined with silane-terminated polyether and cured under the catalysis of a catalyst to obtain a silicone elastomer with high strength and high flexibility.

[0017] Preferably, in the hyperbranched silicone resin, R is vinyl and R′ is methyl, and its structural formula is:

[0018]

[0019] This type of hyperbranched silicone resin is combined with silane-terminated polyether and cured under the catalysis of a catalyst to obtain a silicone elastomer with high hardness, high strength and high ablation resistance.

[0020] The preparation steps of the hyperbranched organosilicon resin are as follows: a coupling agent containing the functional group R or R′ in the structural formula is mixed with a solvent, and then water and hydrochloric acid solution are added to react. After the reaction is completed, the by-products are removed to obtain the hyperbranched organosilicon resin.

[0021] Preferably, a coupling agent containing the functional group R or R′ in the structural formula and a solvent are placed in a three-necked flask equipped with a condenser, a constant-pressure dropping funnel, and a thermometer, and mixed thoroughly. Then, deionized water and a hydrochloric acid solution are added dropwise. After the addition is complete, the mixture is refluxed at 20℃~120℃ for 4h~24h. After the reaction is completed, stirring is stopped, and by-products are removed by rotary evaporation at 20℃~80℃ to obtain a hyperbranched organosilicon resin. The concentration of the hydrochloric acid solution is 36.5%.

[0022] Preferably, the coupling agent is phenyltrimethoxysilane and methyltrimethoxysilane, or phenyltrimethoxysilane and methyloxysilane, or methyltrimethoxysilane, or vinyltrimethoxysilane and methyltrimethoxysilane, or chloromethyltrimethoxysilane and methyltrimethoxysilane.

[0023] Preferably, the solvent is one or more selected from acetone, ethanol, methanol, tetrahydrofuran, ethyl acetate, dichloromethane, chloroform, and toluene. More preferably, the solvent is ethanol.

[0024] The structural formula of the silane-terminated polyether is as follows:

[0025]

[0026] Wherein, R is one of methyl, ethyl, or isopropyl, and R' is one of carbon-carbon bond (CC) or carbamate bond (-NHCOO-).

[0027] The preparation steps of the silane-terminated polyether are as follows: a high molecular weight polyether, a catalyst, and a hydrogen-terminated or isocyanate-terminated silane coupling agent containing the R or R' functional group in the structural formula are mixed and reacted. After the reaction is completed, impurities are removed to obtain the final product.

[0028] Preferably, the reaction temperature is 20℃~150℃ and the reaction time is 2h~10h.

[0029] Preferably, the molar ratio of the high molecular weight polyether to the coupling agent is 1:(2-3); and the catalyst addition amount is 0.05wt% to 5wt%.

[0030] Preferably, the high molecular weight polyether is at least one of hydroxyl-terminated polyethylene oxide, hydroxyl-terminated propylene oxide, vinyl-terminated polyethylene oxide, and vinyl-terminated propylene oxide; the molecular weight of the high molecular weight polyether is 1,000 to 100,000; more preferably, the high molecular weight polyether is a mixture of hydroxyl-terminated propylene oxide and ethylene oxide with a molecular weight of 10,000 or more.

[0031] Preferably, the catalyst is at least one of organotin catalysts such as stannous octoate, dibutyltin dilaurate, and dioctyltin dilaurate, or at least one of titanate catalysts such as tetrabutyl titanate and tetraethyl titanate. The catalyst functions to reduce the activation energy of the material reaction, lower the curing temperature, and increase the curing rate of the material.

[0032] Preferably, the coupling agent is propyltrimethoxysilane isocyanate, and its preparation reaction equation is as follows:

[0033]

[0034] This type of silane-terminated polyether exhibits better compatibility, superior adhesion, and tear resistance with hyperbranched silicone resins. When cured with hyperbranched silicone resins under catalysis, it yields a silicone elastomer with high strength, high adhesion, tear resistance, and ablation resistance.

[0035] The raw materials for the hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer also include at least one of reinforcing fillers, flame-retardant fillers, and ablation-resistant fillers.

[0036] Preferably, the reinforcing filler is at least one selected from titanium dioxide, heavy calcium carbonate, fumed silica, light calcium carbonate, nano-calcium carbonate, silica powder, carbon black, and iron oxide. The reinforcing filler improves the mechanical properties of the material and reduces volume shrinkage during curing, thereby enhancing dimensional stability.

[0037] Preferably, the flame-retardant filler is at least one selected from aluminum hypophosphite, decabromodiphenyl ethane, antimony trioxide, aluminum hydroxide, red phosphorus, ammonium polyphosphate, and magnesium hydroxide; the ablation-resistant filler is at least one selected from hollow glass microspheres, mica powder, kaolin powder, zirconium oxide powder, talc powder, and chopped glass fiber powder. The flame-retardant and ablation-resistant fillers enhance the flame-retardant properties of the material and further improve its high-temperature carbon residue rate, thereby strengthening its ablation resistance.

[0038] The preparation method of the above-mentioned hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer includes the following steps:

[0039] (1) Add a catalyst to the hyperbranched organosilicon resin and stir to obtain component A;

[0040] (2) Use silane-terminated polyether as component B;

[0041] (3) Mix component A and component B evenly and solidify to obtain the hyperbranched organosilicon modified polyether elastomer.

[0042] In practical use, for ease of use and sales, the catalyst and hyperbranched silicone resin are uniformly mixed using a mechanical stirring device to form component A, while the reinforcing filler, flame-retardant and ablation-resistant filler, and silane-terminated polyether are uniformly mixed using a three-roll mill to form component B. When a silicone elastomer is required, components A and B are uniformly mixed and cured under certain conditions to obtain the hyperbranched silicone-modified polyether elastomer.

[0043] Preferably, the curing conditions are curing at room temperature for 7 days or curing at 80°C for 24 hours.

[0044] The above-mentioned hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer is used in the field of high-temperature ablation resistance.

[0045] Invention Principle: This invention provides a novel approach to preparing high-strength, ablation-resistant elastomers. Hyperbranched silicone resin is used as the hard segment, and silane-terminated polyether is used as the soft segment. The two are co-cured under catalysis to obtain a silicone elastomer. Benefiting from the thermal advantages of Si-O-Si bonds, and the larger intramolecular free volume, lower viscosity, and good solubility of hyperbranched silicone polymers, the introduction of hyperbranched silicone polymers into the preparation of silicone elastomers improves viscosity controllability, mechanical properties, ablation resistance, and temperature resistance. Simultaneously, benefiting from the strong intermolecular forces and chain entanglement capabilities of COC bonds in high molecular weight silane-terminated polyethers, the introduction of silane-terminated polyethers into the preparation of silicone elastomers improves the tear resistance, adhesion, and mechanical properties of the material system. The silicone elastomer obtained by copolymerization combines the advantages of both, fundamentally solving the problems of poor mechanical properties, poor heat resistance, and low adhesion inherent in traditional silicone polymers. Meanwhile, by freely adjusting the content of hard and soft segments, novel high-strength ablation-resistant organosilicon elastomers with different characteristics such as ablation resistance, high adhesion, and strong mechanical properties can be prepared.

[0046] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0047] (1) This invention introduces silane-terminated polyether with excellent flexibility and adhesion as a soft segment and hyperbranched silicone resin with excellent temperature resistance, ablation resistance and temperature resistance as a hard segment, thereby achieving a silicone elastomer with excellent adhesion and ablation resistance and temperature resistance. The silicone elastomer of this invention combines the advantages of hyperbranched silicone and silane-terminated polyether, and has excellent ablation resistance, adhesion, mechanical properties and temperature resistance.

[0048] (2) The present invention can freely adjust the mechanical properties, heat protection properties, adhesion, high and low temperature resistance and other performance requirements of the material system according to the actual application scenario by changing the weight ratio of hyperbranched organosilicon components and silane-terminated polyether components in the material system. The formulation is highly flexible and further expands the application prospects of organosilicon polymers.

[0049] (3) This invention provides a method for preparing high-performance, low-cost organosilicon elastomers. The method is simple, has few side reactions, and is easy to scale up. Compared with traditional methods for improving the adhesion and ablation resistance of organosilicon polymers, this preparation method significantly improves the heat protection efficiency and mechanical properties of organosilicon polymer systems without increasing construction procedures and construction difficulty, and can meet the application requirements in special scenarios.

[0050] (4) The elastomer preparation process of the present invention is simple and the production cost is low, and it has a wide range of applications in aerospace, military defense, automotive industry, biology, electronics and medicine. Attached Figure Description

[0051] Figure 1 Here is a photograph of the silicone elastomer obtained in Example 1;

[0052] Figure 2 The graph shows the mechanical properties of the silicone elastomer obtained in Example 1.

[0053] Figure 3 The graph shows the mechanical properties of the silicone elastomer obtained in Example 2.

[0054] Figure 4 The graph shows the thermal stability test results of the silicone elastomer obtained in Example 2.

[0055] Figure 5 The mechanical properties test diagram of the product obtained in Comparative Example 1 is shown.

[0056] Figure 6 The mechanical properties test diagram of the product obtained in Comparative Example 2 is shown.

[0057] Figure 7 The graph shows the thermal stability test results of the product obtained in Comparative Example 3.

[0058] Figure 8 This is a schematic diagram illustrating the temperature resistance performance test of the silicone elastomer obtained in Example 3.

[0059] Figure 9 The graph shows the ablation resistance test results of the silicone elastomer obtained in Example 4.

[0060] Figure 10 The graph shows the heat resistance test results of the silicone elastomer obtained in Example 5. Detailed Implementation

[0061] The present invention will now be described in further detail.

[0062] Example 1

[0063] (1) The preparation steps of silane-terminated polyether are as follows: Under nitrogen protection, 1 mol of hydroxyl-terminated polyethylene oxide with a molecular weight of 10,000, 2 mol of propyltrimethoxysilane isocyanate, and 2 wt% of dibutyltin dibutylsilicate are added to a three-necked flask. The mixture is heated until micro-reflux occurs, and the byproduct is collected by distillation. Then, the temperature is slowly raised to 120℃ and reacted for 6 hours. The temperature is then lowered to 80℃, and the unreacted propyltrimethoxysilane is removed by vacuum removal at -0.1 MPa using an oil pump to obtain a pale yellow transparent silane-terminated polyether.

[0064] (1) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 0.5 mol phenyltrimethoxysilane and 0.5 mol methyltrimethoxysilane, 150 g methanol, and put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer. Mix them evenly, and then add 1.3 mol deionized water and 5 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 120℃ for 4 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 50℃ to obtain phenylmethyl hyperbranched organosilicon resin.

[0065] (3) The preparation method of hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer is as follows:

[0066] S1: Mix 39.5g of hyperbranched silicone resin and 0.5g of dibutyltin disilicate for 30min to obtain component A;

[0067] S2: Use 100g of silane-terminated polyether as component B;

[0068] S3: Mix component A and component B thoroughly and evenly;

[0069] S4: Inject the mixed material into a mold and cure it at room temperature for 14 days to finally obtain a high-strength silicone elastomer.

[0070] The physical image of the silicone elastomer obtained in this embodiment is shown below. Figure 1 As shown. Figure 2 The mechanical property test results of the prepared high-strength silicone elastomer show that the tensile strength of the prepared high-strength silicone elastomer is as high as 6.1 MPa and the elongation at break is close to 320%, exhibiting extremely excellent mechanical properties without the addition of reinforcing fillers.

[0071] Example 2

[0072] (1) The preparation steps of silane-terminated polyether are as follows: Under nitrogen protection, 1 mol of vinyl-terminated polypropylene oxide with a molecular weight of 8000, 2 mol of trimethoxysilane, and 0.1 wt% Karstedt catalyst are added to a three-necked flask. The temperature is then slowly raised to 80℃ and reacted for 2 h, followed by a slow increase to 120℃ and another 2 h. The temperature is then lowered to 80℃, and unreacted trimethoxysilane is removed under vacuum at -0.1 MPa using an oil pump to obtain a pale yellow transparent silane-terminated polyether.

[0073] (2) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 0.5 mol phenyltrimethoxysilane and 0.5 mol vinyltrimethoxysilane, 150 g ethanol, and put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer. Mix them evenly, and then add 1.5 mol deionized water and 5 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 70 °C for 24 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 80 °C to obtain vinylcyclohexyl hyperbranched organosilicon resin.

[0074] (3) The preparation method of hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer is as follows:

[0075] S1: Mix 45g of hyperbranched silicone resin and 5g of dibutyltin dimethylsiloxane for 30min to obtain component A;

[0076] S2: Use 100g of silane-terminated polyether as component B;

[0077] S3: Mix component A and component B thoroughly and evenly;

[0078] S4: Inject the mixed material into a mold and cure it at room temperature for 14 days to finally obtain a high-strength, heat-resistant silicone elastomer.

[0079] Figure 3 , Figure 4 The figures show the mechanical properties and thermal stability test results of the prepared high-strength, high-temperature resistant silicone elastomer. It can be seen that the prepared high-strength, high-temperature resistant silicone elastomer achieves a tensile strength of 4.8 MPa and an elongation at break exceeding 230% without filler addition. Simultaneously, its 5% decomposition temperature exceeds 335℃, its carbon residue at 1000℃ exceeds 43%, and its maximum thermal decomposition rate is only 0.8% / ℃. This demonstrates excellent thermal stability and mechanical properties.

[0080] Example 3

[0081] (1) The preparation steps of silane-terminated polyether are as follows: Under nitrogen protection, 1 mol of a vinyl-terminated polypropylene oxide-ethylene oxide mixture with a molecular weight of 10,000, 2.2 mol of trimethoxysilane, and 0.5 wt% Karstedt catalyst are added to a three-necked flask. The temperature is then slowly raised to 80℃ and reacted for 2 h, followed by a slow increase to 120℃ and another 2 h. The temperature is then lowered to 80℃, and unreacted trimethoxysilane is removed under vacuum at -0.1 MPa using an oil pump to obtain a pale yellow transparent silane-terminated polyether.

[0082] (2) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 1.0 mol of methyltrimethoxysilane and 150 g of ethyl acetate, put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer, mix them evenly, and then add 1 mol of deionized water and 10 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 70°C for 6 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 60°C to obtain methyl hyperbranched organosilicon resin.

[0083] (3) The preparation method of hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer is as follows:

[0084] S1: Mix 20g of hyperbranched silicone resin and 2g of dibutyltin dimethylsiloxane for 30min to obtain component A;

[0085] S2: Use 80g of silane-terminated polyether as component B;

[0086] S3: Mix component A and component B thoroughly and evenly;

[0087] S4: Inject the mixed material into a mold and cure it at room temperature for 14 days to finally obtain a heat-resistant silicone elastomer.

[0088] Figure 8 The image shows the temperature resistance test results of the prepared elastomer. It can be seen from the image that the prepared temperature-resistant silicone elastomer still maintains the integrity of its morphology after aging at 120℃ for 12 hours. Compared with the complete liquefaction and decomposition of ordinary silane-terminated polyether, the temperature resistance performance is significantly improved, which proves that the introduction of hyperbranched silicone resin as a crosslinking site greatly improves the temperature resistance performance of the material system.

[0089] Example 4

[0090] (1) The preparation steps of silane-terminated polyether are as follows: Under nitrogen protection, 1 mol of vinyl-terminated polypropylene oxide with a molecular weight of 10000, 2.5 mol of trimethoxysilane, and 1 wt% of Karstedt catalyst are added to a three-necked flask. The temperature is then slowly raised to 80℃ and reacted for 4 h, followed by a slow increase to 150℃ and a reaction for 2 h. The temperature is then lowered to 80℃, and unreacted trimethoxysilane is removed under vacuum at -0.1 MPa using an oil pump to obtain a pale yellow transparent silane-terminated polyether.

[0091] (2) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 0.5 mol vinyltrimethoxysilane and 0.5 mol methyltrimethoxysilane, 150 g tetrahydrofuran, and put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer. Mix them evenly, and then add 2 mol deionized water and 1.5 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 100 °C for 4 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 80 °C to obtain vinylmethyl hyperbranched organosilicon resin.

[0092] (3) The preparation method of hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer is as follows:

[0093] S1: Mix 49.5g of hyperbranched silicone resin and 0.5g of dibutyltin disilicate for 30 minutes to obtain component A;

[0094] S2: 40g of silane-terminated polyether and 20g of fumed silica were stirred in a three-roll mill for 2 hours as component B.

[0095] S3: Mix component A and component B thoroughly and evenly;

[0096] S4: Inject the mixed material into a mold and cure it at room temperature for 10 days to finally obtain an ablation-resistant silicone elastomer.

[0097] Figure 9 The ablation resistance test results of the prepared ablation-resistant elastomer are shown in the figure. The figure shows that the prepared ablation-resistant silicone elastomer maintained its overall morphological integrity after being placed in a muffle furnace at 800℃ for 5 minutes. In contrast, pure hyperbranched silicone resin and pure silane-terminated polyether both exhibited thermal oxidative decomposition. This demonstrates the superior ablation resistance of the constructed silicone elastomer.

[0098] Example 5

[0099] (1) The preparation steps of silane-terminated polyether are as follows: Under nitrogen protection, 1 mol of vinyl-terminated polyethylene oxide with a molecular weight of 8000, 3 mol of trimethoxysilane, and 0.5 wt% Karstedt catalyst are added to a three-necked flask. The temperature is then slowly raised to 80℃ and reacted for 4 h, followed by a slow increase to 120℃ and another 4 h. The temperature is then lowered to 60℃, and unreacted trimethoxysilane is removed under vacuum at -0.1 MPa using an oil pump to obtain a pale yellow transparent silane-terminated polyether.

[0100] (2) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 0.5 mol vinyltrimethoxysilane and 0.5 mol methyltrimethoxysilane, 150 g acetone, respectively, and put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer. Mix them evenly, and then add 1.1 mol deionized water and 1 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 150 °C for 2 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 60 °C to obtain methyl hyperbranched organosilicon resin.

[0101] (3) The preparation method of hyperbranched organosilicon-modified high-strength polyether-type ablation-resistant elastomer is as follows:

[0102] S1: Mix 39.5g of hyperbranched silicone resin and 0.5g of dibutyltin disilicate for 30min to obtain component A;

[0103] S2: 50g of silane-terminated polyether, 10g of aluminum hydroxide, 10g of aluminum hypophosphite, 10g of hollow glass microspheres, 10g of silica powder, and 10g of kaolin are mixed in a three-roll mill for 2 hours to form component B.

[0104] S3: Mix component A and component B thoroughly and evenly;

[0105] S4: The mixed material is injected into a mold and cured at 100°C for 48 hours to finally obtain a heat-resistant and ablation-resistant silicone elastomer.

[0106] Figure 10 The image shows the ablation test results of the prepared ablation-resistant elastomer under open flame. The image reveals that the prepared ablation-resistant silicone elastomer exhibits excellent heat resistance under 1000℃ alcohol torch ablation. After 5 minutes of ablation, the back temperature is only 95℃, and after 30 minutes, the back temperature does not exceed 250℃. Furthermore, the elastomer maintains its overall morphology intact after 30 minutes of ablation, without significant cracking or breakage. This demonstrates excellent ablation resistance and heat protection.

[0107] Example 6

[0108] (1) The preparation steps of silane-terminated polyether are as follows: Under nitrogen protection, 1 mol of hydroxyl-terminated polypropylene oxide-ethylene oxide mixture with a molecular weight of 10000, 2.2 mol of propyltrimethoxysilane isocyanate, and 5 wt% of dibutyltin disilicate catalyst are added to a three-necked flask; then the temperature is slowly raised to 80℃ and reacted for 6 h, then the temperature is slowly raised to 120℃ and reacted for 4 h, then the temperature is lowered to 80℃, and the unreacted trimethoxysilane is removed by vacuum removal at -0.1 MPa using an oil pump to obtain a light yellow transparent silane-terminated polyether.

[0109] (2) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 0.5 mol phenyltrimethoxysilane and 0.5 mol methyltrimethoxysilane and 150 g dichloromethane respectively, put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer, mix them evenly, and then add 1.3 mol deionized water and 3 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 70℃ for 12 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 60℃ to obtain phenyl hyperbranched organosilicon resin.

[0110] (3) The preparation method of hyperbranched organosilicon-modified polyether elastomer is as follows:

[0111] S1: Mix 39.5g of hyperbranched silicone resin and 0.5g of dibutyltin disilicate for 30min to obtain component A;

[0112] S2: 30g of silane-terminated polyether, 10g of ammonium polyphosphate, 10g of red phosphorus, 10g of decabromodiphenyl ethane, 10g of antimony trioxide, 10g of heavy calcium carbonate, 10g of nano calcium carbonate, and 10g of talc are stirred in a three-roll mill for 2 hours as component B.

[0113] S3: Mix component A and component B thoroughly and evenly;

[0114] S4: Inject the mixed material into a mold and cure it at 100°C for 48 hours to finally obtain a solvent-resistant, flame-retardant, high-strength organosilicon elastomer.

[0115] Example 7

[0116] (1) The preparation steps of silane-terminated polyether are as follows: under nitrogen protection, 1 mol of hydroxyl-terminated polypropylene oxide with a molecular weight of 10000, 2.2 mol of propyltrimethoxysilane isocyanate, and 5 wt% of dibutyltin disilicate catalyst are added to a three-necked flask; then the temperature is slowly raised to 80℃ and reacted for 6 h, then the temperature is slowly raised to 120℃ and reacted for 4 h, then the temperature is lowered to 80℃, and the unreacted trimethoxysilane is removed by vacuum at -0.1 MPa using an oil pump to obtain a light yellow transparent silane-terminated polyether.

[0117] (2) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 0.5 mol of chloromethyltrimethoxysilane and 0.5 mol of methyltrimethoxysilane, 150 g of chloroform, and put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer. Mix them evenly, and then add 1.3 mol of deionized water and 3 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 70°C for 6 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 60°C to obtain flame-retardant hyperbranched organosilicon resin.

[0118] (3) The preparation method of hyperbranched organosilicon-modified polyether elastomer is as follows:

[0119] S1: Mix 39.5g of hyperbranched silicone resin and 0.5g of dibutyltin disilicate for 30min to obtain component A;

[0120] S2: 40g of silane-terminated polyether, 10g of zirconium oxide, 10g of aluminum hypophosphite, 10g of light calcium carbonate, and 10g of titanium dioxide are stirred in a three-roll mill for 2 hours to form component B.

[0121] S3: Mix component A and component B thoroughly and evenly;

[0122] S4: Inject the mixed material into a mold and cure it at 100°C for 48 hours to finally obtain a flame-retardant high-strength organosilicon elastomer.

[0123] Example 8

[0124] (1) The preparation steps of silane-terminated polyether are as follows: Under nitrogen protection, 1 mol of hydroxyl-terminated polyethylene oxide-propylene oxide mixture with a molecular weight of 10,000, 2.2 mol of propyltrimethoxysilane isocyanate, and 5 wt% of dibutyltin disilicate catalyst are added to a three-necked flask; then the temperature is slowly raised to 80℃ and reacted for 6 h, then the temperature is slowly raised to 120℃ and reacted for 4 h, then the temperature is lowered to 80℃, and the unreacted trimethoxysilane is removed by vacuum removal at -0.1 MPa using an oil pump to obtain a light yellow transparent silane-terminated polyether.

[0125] (2) The preparation steps of hyperbranched organosilicon resin are as follows: Weigh 0.5 mol phenyltrimethoxysilane and 0.5 mol methyltrimethoxysilane, 150 g chloroform, respectively, and put them into a three-necked flask equipped with a condenser, a constant pressure dropping funnel and a thermometer. Mix them evenly, and then add 1.3 mol deionized water and 3 ml of 36.5% hydrochloric acid dropwise. After the addition is completed, reflux at 70°C for 12 h. After the reaction is completed, stop stirring and remove the by-products by rotary evaporation at 60°C to obtain heat-resistant self-ceramic hyperbranched organosilicon resin.

[0126] (3) The preparation method of hyperbranched organosilicon-modified polyether elastomer is as follows:

[0127] S1: Mix 39.5g of hyperbranched silicone resin and 0.5g of dibutyltin disilicate for 30min to obtain component A;

[0128] S2: 70g of silane-terminated polyether, 10g of iron oxide red, 10g of carbon black, 5g of chopped glass fiber powder, and 5g of magnesium hydroxide are stirred in a three-roll mill for 2 hours to form component B.

[0129] S3: Mix component A and component B thoroughly and evenly;

[0130] S4: Inject the mixed material into a mold and cure it at room temperature for 7 days to finally obtain an aging-resistant and temperature-resistant silicone elastomer.

[0131] Comparative Example 1

[0132] The remaining steps of this comparative example are the same as those in Example 1, except that the phenylmethyl hyperbranched silicone resin is replaced with methyltrimethoxysilane. The results showed that: Figure 5 The results show that the tensile strength of the cured material is only 0.8 MPa and the elongation at break is only 262%, which is significantly lower than that of Example 1. This demonstrates that introducing hyperbranched silicone resin into the construction of novel silicone elastomers has excellent mechanical properties.

[0133] Comparative Example 2

[0134] The remaining steps of this comparative example are the same as in Example 1, except that the silane-terminated polyether is replaced with 107 silicone rubber. The results show that: Figure 6 The results show that the tensile strength of the cured material is 5.56 MPa, but the elongation at break is only 49%, which is significantly lower than that of Example 1. This demonstrates that introducing silane-terminated polyethers into the construction of novel organosilicon elastomers has excellent flexibility.

[0135] Comparative Example 3

[0136] The remaining steps of this comparative example are the same as those in Example 2, except that vinylmethyl hyperbranched silicone resin is replaced with vinyltrimethoxysilane. The results showed that: Figure 7 The results show that the 5% thermal decomposition temperature of the cured material is only 311℃, the maximum thermal decomposition rate is as high as 1.7% / ℃, and the residual carbon rate at 1000℃ is only 5.3%. Compared with Example 2, the thermal stability and ablation resistance are significantly reduced, which proves that introducing hyperbranched organosilicon resin into the construction of novel organosilicon elastomers has excellent temperature resistance and ablation resistance.

[0137] Comparative Example 4

[0138] The remaining steps of this comparative example are the same as those in Example 2, except that trimethoxysilane is replaced with dimethoxysilane in the preparation step of the silane-terminated polyether. The results showed that the tensile strength of the cured material was 0.56 MPa and the elongation at break was 230%, which is significantly lower than the mechanical strength of the material in Example 2. This demonstrates that using a trifunctional silane coupling agent as a capping agent in the material is beneficial for increasing the crosslinking density, thereby obtaining a novel organosilicon elastomer with excellent mechanical properties.

[0139] Comparative Example 5

[0140] The remaining steps in this comparative example are the same as in Example 1, except that in the preparation step of the silane-terminated polyether, isocyanate propyltrimethoxysilane is replaced with glycidyl ether propyltrimethoxysilane. The result was that the material could not be cured normally, and only a semi-cured gel material was obtained. This demonstrates that isocyanate propyltrimethoxysilane has high reactivity, and its use as a capping agent in materials is beneficial for successful modification, leading to novel organosilicon elastomers with excellent mechanical properties. The glycidyl ether group, due to its low reactivity, results in a low reaction conversion rate, thus having a significant impact on the material properties.

[0141] Comparative Example 6

[0142] The remaining steps of this comparative example are the same as those in Example 3, except that the 36.5% hydrochloric acid solution was replaced with ammonia in the preparation step of the hyperbranched silicone resin. The result showed that the obtained hyperbranched silicone resin was in a semi-gel state, with high viscosity and no flowability, and it cured rapidly in air, exhibiting poor processing performance and no practical application value. This demonstrates that the alkaline catalyst has high catalytic activity during the synthesis of hyperbranched silicone resin, resulting in a hyperbranched silicone resin with poor practicality and unsuitable for normal use in this material.

[0143] Comparative Example 7

[0144] The remaining steps of this comparative example are the same as those of Example 3, except that the 36.5% hydrochloric acid solution was replaced with acetic acid in the preparation step of the hyperbranched silicone resin. The results showed that when the hyperbranched silicone resin was used as component A in the preparation of silicone elastomers, the tensile strength of the obtained material was only 1 MPa and the elongation at break was only 100%. Compared with the mechanical strength of the material in Example 3, the mechanical strength of the material was significantly reduced, which proved that the catalytic activity of acetic acid as a catalyst was low. The low degree of polymerization of the obtained hyperbranched silicone resin resulted in low crosslinking degree of the cured material and poor material performance.

[0145] Comparative Example 8

[0146] The remaining steps of this comparative example are the same as those in Example 1, except that the amount of hyperbranched silicone resin added is adjusted to 5g. The results showed that the tensile strength of the obtained material was only 0.2MPa, the elongation at break was only 50%, the 5% decomposition temperature was only 270℃, the residual carbon rate at 1000℃ was only 6.5%, and the maximum thermal decomposition rate exceeded 3% / ℃. This demonstrates that a low amount of hyperbranched silicone resin has a significant impact on the mechanical properties and temperature resistance of the material.

[0147] Comparative Example 9

[0148] The remaining steps of this comparative example are the same as those of Example 1, except that the amount of silane-terminated polyether is adjusted to 5g. The results show that the tensile strength of the obtained material is 8MPa, but the elongation at break is only 8%, which proves that when the amount of silane-terminated polyether added is low, the material exhibits hard plastic characteristics and loses its original excellent elasticity and toughness.

[0149] The performance comparison of different formulation systems in the above embodiments and comparative examples is shown in Table 1 below.

[0150] Table 1. Performance comparison of different formulation systems in each embodiment and comparative example.

[0151]

Claims

1. Hyperbranched organosilicon-modified high-strength polyether ablative-resistant elastomer, characterized in that, Comprising A component and B component, the mass percentage of A component and B component is 10-90%:90-10%; The A component comprises the following raw materials by weight: hyperbranched silicone resin: 100-25 parts; catalyst: 0-5 parts, not including 0; flame-retardant filler: 0-70 parts; ablative filler: 0-70 parts; reinforcing filler: 0-70 parts; The B component comprises the following raw materials by weight: silane-terminated polyether: 100-25 parts; Catalyst: 0-5 parts; flame-retardant filler: 0-70 parts; ablative filler: 0-70 parts; reinforcing filler: 0-70 parts; The catalyst is at least one of stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, tetrabutyl titanate, and tetraethyl titanate; The structural formula of the hyperbranched silicone resin is: ； Wherein, R is one or more combinations of methyl, phenyl, vinyl, chloromethyl, glycidyl ether propyl, and R' is methyl; The preparation steps of the hyperbranched silicone resin are: mixing a coupling agent containing R or R' functional groups in the structural formula and a solvent, then adding water and hydrochloric acid solution for reaction, removing by-products after the reaction is completed, and obtaining the hyperbranched silicone resin; the coupling agent is phenyl trimethoxysilane and methyl trimethoxysilane, or phenyl trimethoxysilane and vinyl trimethoxysilane, or methyl trimethoxysilane, or vinyl trimethoxysilane and methyl trimethoxysilane, or chloromethyl trimethoxysilane and methyl trimethoxysilane; The structural formula of the silane-terminated polyether is: ； Wherein, R is one of methyl, ethyl, and isopropyl, and R' is one of carbon-carbon bond (C-C) and carbamate bond (-NHCOO-); The preparation steps of the silane-terminated polyether are: mixing high molecular weight polyether, catalyst, and end-hydrogen or end-isocyanate group silane coupling agent containing R or R' functional groups in the structural formula for reaction, and removing impurities after the reaction is completed; the end-isocyanate group silane coupling agent is isocyanate propyl trimethoxysilane; The molar ratio of the high molecular weight polyether to the coupling agent is 1:(2-3); the addition amount of the catalyst is 0.05wt%-5wt%.

2. The hyperbranched silicone-modified high-strength polyether ablative-resistant elastomer according to claim 1, characterized in that, The high molecular weight polyether is at least one of end-hydroxyl polyethylene oxide, end-hydroxyl polypropylene oxide, end-vinyl polyethylene oxide, and end-vinyl polypropylene oxide; the molecular weight of the high molecular weight polyether is 1000-100000.

3. A process for the preparation of the hyperbranched organosilicon-modified high-strength polyether-based ablative-resistant elastomer according to claim 1, characterized in that, Comprising the following steps: (1) adding a catalyst to the hyperbranched silicone resin and stirring to obtain the A component; (2) taking the silane-terminated polyether as the B component; (3) uniformly mixing the A component and the B component raw materials, and curing and forming, to obtain the hyperbranched silicone modified polyether elastomer.

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