High-temperature-resistant organic silicon elastomer with high mechanical property as well as preparation and application of high-temperature-resistant organic silicon elastomer

Abstract

The invention discloses a high-temperature-resistant organic silicon elastomer with high mechanical property as well as preparation and application thereof, and belongs to the technical field of functional materials. The high-temperature-resistant organic silicon elastomer with high mechanical property is prepared from the following raw materials: hydroxyl silicone oil, white carbon black nanoparticles, a silane monomer cross-linking agent, a silane coupling agent and stannous octoate, and the catalyst also comprises cage-shaped titanium oxygen cluster molecules. According to the invention, by simultaneously using the components, the composite high-temperature-resistant organic silicon elastomer material can be provided, the thermal collapse temperature of the material is almost 500 DEG C, and the composite high-temperature-resistant organic silicon elastomer material is good in thermal stability and mechanical tensile strength and wide in application prospect.

Description

Technical Field

[0001] This invention belongs to the field of functional materials technology, specifically relating to a high-temperature resistant organosilicon elastomer with high mechanical properties, its preparation and application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Organosilicon elastomers (SE) are three-dimensional network polymers with varying degrees of crosslinking, formed through condensation and addition reactions of linear polysiloxanes, silicon monomer crosslinking agents, and catalysts. Their excellent high and low temperature resistance, non-flammability, electrical insulation, ozone resistance, biocompatibility, and processability make them widely used in 3D printing, electronics, intelligent robotics, aerospace, automotive, medical, and construction industries. Ordinary organosilicon elastomers can be used continuously at temperatures ranging from -40℃ to 200℃. However, in specialized fields such as aerospace, photovoltaic modules, and chromatographic separation, materials are required to operate continuously at temperatures above 300℃ while maintaining good optical, thermal, electrical, and mechanical stability.

[0004] Ordinary silicone elastomer materials obviously cannot meet the requirements of these special fields. Some of the high-temperature resistant silicone elastomers disclosed in the prior art can only reach 440°C, and higher temperatures are not yet achievable. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high-temperature resistant organosilicon elastomer with high mechanical properties, its preparation, and its applications. The preparation method of the titanium oxide cluster composite high-temperature resistant organosilicon elastomer is studied from three perspectives: optimization of the main and side chain structure, screening of crosslinking agents, and addition of heat-resistant reinforcing agents. Specifically, optimization of the main and side chain structure refers to viscosity optimization, and the addition of heat-resistant reinforcing agents refers to the addition of silica and cage-like titanium oxide cluster molecules.

[0006] This invention relates to the preparation of silica nanoparticle-modified organosilicon elastomers and methods for preparing titanium-oxygen cluster composite nanoparticle-modified organosilicon elastomers. By comparing the high-temperature resistance and tensile strength of organosilicon elastomers modified by different methods, the optimal conditions for titanium-oxygen cluster composite nanoparticle-modified high-temperature resistant organosilicon elastomers were obtained. This provides a composite high-temperature resistant organosilicon elastomer material for specialized fields such as aerospace, photovoltaic modules, and chromatographic separation. This material has a thermal collapse temperature of nearly 500℃, and exhibits good thermal stability and tensile strength, showing broad commercial application prospects.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a high-temperature resistant organosilicon elastomer with high mechanical properties, the raw materials of which include hydroxyl silicone oil, silica nanoparticles, silane monomer crosslinking agent, silane coupling agent and stannous octoate. The molar ratio of hydroxyl silicone oil, silane coupling agent, and stannous octoate is 1:(1.2~2):(0.2~1). The preferred ratio is 1:(1.5~1.7):(0.5~0.7), and the most preferred ratio is 1:1.6:0.6.

[0008] The high-temperature resistant silicone elastomer product provided by this invention has a thermal collapse temperature of 450°C or higher, preferably 490°C or higher (e.g., 450~500°C, more preferably 490~500°C). Its tensile strength is 2 MPa or higher, preferably 2.5 MPa or higher (e.g., 2~3 MPa, more preferably 2.5~3 MPa).

[0009] In one or more embodiments, the hydroxyl silicone oil is a methyl-terminated hydroxyl silicone oil with a viscosity of 800~4500 cps, specifically 800 cps, 1000 cps, 1200 cps, 1500 cps, 1800 cps, 2000 cps, 2200 cps, 2500 cps, 2800 cps, 3000 cps, 3200 cps, 3500 cps, 3800 cps, 4000 cps, 4200 cps, 4500 cps, etc., preferably 800~1200 cps or 3500~4500 cps, more preferably 800~1200 cps or 3800~4200 cps. When the viscosity is 20000 cps, it is difficult to cure. Experimental results show that viscosity can affect the ease of degassing during the preparation process, curing time (and may even lead to difficulty in curing the product, preventing the formation of an elastomer), tensile properties, etc.

[0010] In one or more embodiments, the silane monomer crosslinking agent is one of methyltrimethoxysilane or phenyltriethoxysilane, preferably methyltrimethoxysilane. The mass of the silane monomer crosslinking agent is 20-50% of the hydroxyl silicone oil, specifically 20%, 22%, 23%, 24%, 25%, 28%, 30%, 35%, 40%, 45%, 46%, 47%, 48%, 49%, 50%, etc., preferably 45%-50%.

[0011] The mass of the silica nanoparticles is 5-20% of the hydroxyl silicone oil, specifically 5%, 8%, 10%, 12%, 14%, 15%, 16%, 18%, or 20%, preferably 10-20%, and most preferably 18-20%. If the addition exceeds 20%, adverse effects will occur, such as decreased tensile strength, prolonged curing time, or even failure to cure.

[0012] The main component of silica nanoparticles is silicon dioxide. From the perspective of organosilicon elastomers, silica nanoparticles have better compatibility as an additive (the addition amount can be as high as 20%), while titanium dioxide nanoparticles have poorer compatibility (the addition amount is 2~4%). Secondly, the fumed silica used in this invention has smaller and more concentrated sizes, so it can be used as a reinforcing agent.

[0013] In one or more embodiments, it also includes titanium oxide clusters (Ti 12 Nanoparticle additives, the titanium oxide clusters (Ti) 12 ) is a cage-like titanium oxide cluster molecule.

[0014] Titanium oxide clusters (Ti 12 The mass of the nano-additive is 0.1-1% of the hydroxyl silicone oil, specifically 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, preferably 0.4-0.6%, and most preferably 0.4-0.5%.

[0015] As the most preferred embodiment, to obtain a silicone elastomer product with both higher thermal collapse temperature and higher mechanical properties, as in Example 2. The hydroxyl silicone oil is a methyl-terminated hydroxyl silicone oil with a viscosity of 3800~4200 cpscps; the mass of the silane monomer crosslinking agent (methyltrimethoxysilane) is 45~50% of the hydroxyl silicone oil; the mass of the silica nanoparticles is 18~20% of the hydroxyl silicone oil; and the mass of the titanium dioxide clusters (TiO2) is... 12 The mass of the nano-additive is 0.4~0.5% of the hydroxyl silicone oil.

[0016] The titanium oxide clusters in this invention provide a smaller, perfectly uniform reinforcing effect, exhibiting a binary synergistic effect. Compared to titanium oxide clusters used in existing technologies, such as CTOC (Ti 32 O 16 (EG) 32 (PAc) 16 (EtO) 16 The Ti used in this invention has a hollow ring structure and is anisotropic; 12 It has a cage-like, spherical structure and isotropic properties, making it a better additive. Therefore, in this invention, by using both silica nanoparticles and cage-like titanium dioxide cluster molecules, the high-temperature resistant silicone elastomer prepared by this invention exhibits improved high-temperature resistance (from 440°C to 495°C) and mechanical properties (such as tensile properties).

[0017] Silica is prepared by gas-phase or precipitation methods (the raw materials used vary depending on the method). Through various process modifications, hydrophobic and hydrophilic types of silica with different particle sizes are obtained. Typically, silica has a surface rich in functional groups such as hydroxyl groups, a small particle size, and a large specific surface area, allowing for better blending and compatibility with organosilicones. The type, grade, batch, and dosage of silica all have varying degrees of impact on product performance.

[0018] In this invention, in order to achieve better technical results, the type and variety of silica were screened in the early stage.

[0019] (1) The silica purchased from Shanghai Yuanjiang Chemical Co., Ltd. is of type A200. This silica is hydrophilic and difficult to cure, so it is not suitable for use in this invention.

[0020] (2) Hydrophobic silica was purchased from Shanghai Yuanjiang Chemical Co., Ltd. The silicone elastomer prepared according to the method provided in this invention has relatively low mechanical properties (the tensile strength was initially measured to be 1.1 MPa using a tensile tester).

[0021] (3) The BT-40 type of precipitated silica (hydrophilic type) purchased from Zhengzhou Hongjintang Trading Co., Ltd. is difficult to cure, so this invention is not suitable.

[0022] (4) The "Sailike LK-3000" model of silica sample provided by Zhengzhou Hongjintang Trading Co., Ltd. is difficult to cure during the experiment, so it is not suitable for use in this invention.

[0023] (5) The silica nanoparticles used in the embodiments of the present invention are fumed silica, which is ultrafine hydrophobic silica A-100 purchased from Zhengzhou Tiandaolun Chemical Products Co., Ltd.

[0024] Obviously, in the system of this invention, hydrophilic silica is difficult to cure, while in the experiment, the amount of hydrophobic silica used needs to be appropriate for good curing, and there are many types of hydrophobic silica. Therefore, in order to achieve the technical effect of this invention, ultrafine hydrophobic silica A-100 is used.

[0025] Or, titanium oxide clusters (Ti 12 The nano-additive solution has a volume ratio of KH550 and stannous octoate of (0.5~2):(0.05~0.2):(0.15~0.3), preferably (0.8~1.2):(0.08~0.12):(0.18~0.22).

[0026] Titanium oxide clusters (Ti 12 The nano-additive solution is a chloroform solution of titanium oxide clusters, and the titanium oxide clusters (Ti) 12The concentration of the nano-additive solution is 50~200 mg / mL, specifically 50 mg / mL, 60 mg / mL, 70 mg / mL, 80 mg / mL, 90 mg / mL, 100 mg / mL, 110 mg / mL, 120 mg / mL, 130 mg / mL, 140 mg / mL, 150 mg / mL, 160 mg / mL, 170 mg / mL, 180 mg / mL, 190 mg / mL, 200 mg / mL, etc., preferably 80~120 mg / mL, and most preferably 100 mg / mL.

[0027] Alternatively, the mass-to-volume ratio of hydroxyl silicone oil to stannous octoate is (15~25):(0.05~0.2), preferably (20~25):(0.08~0.12).

[0028] The titanium oxide clusters (Ti 12 (Ti) is a cage-like titanium oxide cluster molecule with 12 Ti elements. 12 O 16 (OPr i ) 16 Its outermost ring has 16 alkoxy groups and i PrO - The presence of anions and abundant organic ligands gives this titanium oxide cluster good solution processability.

[0029] The titanium oxide clusters (Ti 12 The preparation method of ) includes: adding isopropyl titanate to a mixed solution of alcohol and water, mixing well, and then hydrothermally reacting at 90~110℃ for 2~4 days to obtain the product.

[0030] Furthermore, the alcohol-water mixture is a mixture of isopropanol and water in a volume ratio of (150~200):(5~10). The mass-volume ratio of isopropyl titanate to water is (100~150):(5~10).

[0031] Furthermore, the titanium oxide clusters (Ti 12 The preparation method of Ti further includes: restoring the clear solution obtained after hydrothermal reaction to room temperature, evaporating under reduced pressure to dryness, and dissolving the resulting solid in heptane by heating (70~90℃). Then, this solution is stored at low temperature (-25~-15℃) for 10~15h, filtered, and washed multiple times with acetonitrile to obtain a crude crystalline product. Finally, the crude crystalline product is recrystallized in heptane to obtain Ti. 12 product.

[0032] Titanium oxide clusters (Ti 12The information has been published in the literature (DOI: 10.1021 / ja00071a075, Dodecatitanates: a new family of stable polyoxotitanates, Journal of the American Chemical Society).

[0033] in, i PrO - This is an abbreviation for deprotonated isopropanol. The structural formula of this titanium oxide cluster is as follows: It should be noted that the solid and dashed lines in the structural formula only represent the three-dimensional configuration and do not distinguish the type of bonding.

[0034] Secondly, the present invention provides a method for preparing the above-mentioned high-temperature resistant organosilicon elastomer with high mechanical properties, comprising the following steps: First, thoroughly mix hydroxyl silicone oil and silica nanoparticles until homogeneous. Then, add silane monomer crosslinking agent and stir until homogeneous. Finally, add titanium oxide clusters (TiO2). 12 Nano-additives were added, and finally KH550 and stannous octoate were added, followed by static curing.

[0035] In one or more embodiments, after adding stannous octoate and KH550, the stirring speed is 400~600 r / min, preferably 550 r / min, and the stirring time is 5~20 min, preferably 10 min; In one or more embodiments, vacuum degassing is further included before static curing, with vacuum degassing lasting 5 to 20 minutes.

[0036] Thirdly, the present invention provides applications of the above-mentioned high-temperature resistant organosilicon elastomer with high mechanical properties in fields such as 3D printing, electronics and electrical engineering, intelligent robots, aerospace, automobiles, medical, and construction.

[0037] One or more of the above technical solutions have the following advantages or beneficial effects: (1) The present invention prepares an organosilicon elastomer by adding silica nanoparticles in a combination of hydroxyl silicone oil, silane monomer crosslinking agent, silane coupling agent and stannous octoate, with a collapse temperature of 456°C.

[0038] (2) This invention incorporates cage-like titanium oxide cluster nanoparticles along with silica nanoparticles to prepare a titanium oxide cluster-silica composite modified organosilicon elastomer. The process is simple, the raw materials are inexpensive and readily available, and it is environmentally friendly. The product has a thermal collapse temperature close to 500℃, significantly enhanced heat resistance, and low production cost, which is beneficial to the development of the organosilicon industry. Furthermore, its tensile strength reaches 3MPa. Therefore, the organosilicon elastomer prepared by this invention exhibits good performance in both high-temperature resistance and mechanical properties.

[0039] (3) The preparation of titanium oxide cluster nanoparticles is made from inexpensive raw materials, simple steps, mild conditions, and the product has a nanoscale particle size and strong solution processability, which is conducive to the covalent composite of silica, titanium oxide clusters and organosilicon elastomers. Attached Figure Description

[0040] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0041] Figure 1 The TGA spectrum of the high-temperature resistant organosilicon elastomer prepared by adding about 50% of silane monomer crosslinking agent (methyltrimethoxysilane) and 20% of fumed silica in Example 1 of this invention. Figure 2 The TGA spectrum of the high-temperature resistant organosilicon elastomer prepared by adding about 50% silane monomer crosslinking agent (methyltrimethoxysilane), 20% silica and 0.5% titanium dioxide nanoparticles in Example 2 of this invention. Figure 3 The TGA spectrum of the high-temperature resistant organosilicon elastomer prepared by adding about 50% silane monomer crosslinking agent (methyltrimethoxysilane), 10% silica and 0.5% titanium dioxide nanoparticles in Example 3 of the present invention. Figure 4 The TGA spectrum of the high-temperature resistant organosilicon elastomer prepared by adding about 25% silane monomer crosslinking agent (methyltrimethoxysilane), 20% silica and 0.5% titanium dioxide nanoparticles in Example 4 of this invention. Figure 5 The TGA spectrum of the high-temperature resistant organosilicon elastomer prepared by adding about 50% silane monomer crosslinking agent (phenyltriethoxysilane), 20% silica and 0.5% titanium dioxide nanoparticles in Example 5 of this invention. Figure 6 The TGA spectrum of the high-temperature resistant organosilicon elastomer prepared by adding about 50% silane monomer crosslinking agent (methyltrimethoxysilane), 20% silica and 0.5% titanium dioxide nanoparticles in Example 6 of this invention. Figure 7The TGA spectrum of the high-temperature resistant organosilicon elastomer prepared by adding about 50% silane monomer crosslinking agent (methyltrimethoxysilane) and 0.5% titanium oxide cluster nanoparticles to Comparative Example 4 of this invention. Figure 8 The color change of the organosilicon elastomer prepared in Example 2 of this invention before and after being placed in a constant temperature drying oven (200°C, heated for 2 hours) is compared. Detailed Implementation

[0042] It should be noted that, Figures 1-7 The structural formula shown is that of a silane monomer crosslinking agent.

[0043] The titanium oxide clusters (Ti) in the following examples 12 The preparation method of ) includes the following steps: First, isopropyl titanate (120 g, 422 mmol) was slowly added to a mixed solution of water (7.8 ml, 433 mmol) and isopropanol (160 ml), followed by vigorous shaking for about 30 seconds. Then, this solution was transferred to an autoclave and heated at 100°C for 3 days. The resulting clear solution was allowed to return to room temperature, evaporated under reduced pressure to dryness, and the resulting solid was dissolved in heptane (80 ml) at 80°C. This solution was then stored at -20°C for 12 hours, filtered, and washed three times with 10 ml of acetonitrile to obtain a crude crystalline product. Finally, the crude crystalline product was recrystallized in heptane (60 ml) to obtain Ti. 12 Product 0.2g.

[0044] In this invention, unless otherwise specified, all other test materials and instruments are conventional test materials in the field and can be purchased through commercial channels.

[0045] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0046] Example 1: Preparation of High-Temperature Resistant Organosilicon Elastomer by Modification of Silica Nanoparticles The specific preparation steps are as follows: Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 4000 cps, add 4.2 g of silica nanoparticles and stir until homogeneous. Then add 10 g of methyltrimethoxysilane and stir at 550 r / min for 5 min. Next, add 0.1 mL of stannous octoate and 0.2 mL of KH550, and continue stirring at 550 r / min for 10 min to ensure thorough mixing. Degas under vacuum and allow to stand for curing.

[0047] The TGA curves of the organosilicon elastomers prepared by this method are as follows: Figure 1As shown, its collapse temperature is 456℃.

[0048] Example 2: Preparation of High-Temperature Resistant Organosilicon Elastomers by Modification with Titanium Oxide Cluster Composite Nanoparticles The specific preparation steps are as follows: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 4000 cps, add 4.2 g of silica nanoparticles to it, and stir at 550 r / min for 5 min to mix evenly.

[0049] 2) Add 10g of methyltrimethoxysilane to the above reaction system and continue stirring at 550r / min for 5min to mix thoroughly.

[0050] 3) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0051] 4) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0052] The TGA curves of the organosilicon elastomers prepared by this method are as follows: Figure 2 As shown, its collapse temperature is 495℃.

[0053] Example 3: Preparation of High-Temperature Resistant Organosilicon Elastomers by Modification with Titanium Oxide Cluster Composite Nanoparticles The specific preparation steps are as follows: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 4000 cps, add 2.1 g of silica nanoparticles to it, and stir at 550 r / min for 5 min to mix evenly.

[0054] 2) Add 10g of methyltrimethoxysilane to the above reaction system and continue stirring at 550r / min for 5min to mix thoroughly.

[0055] 3) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0056] 4) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0057] The TGA curves of the organosilicon elastomers prepared by this method are as follows: Figure 3 As shown, its collapse temperature is 471℃.

[0058] Example 4: Preparation of High-Temperature Resistant Organosilicon Elastomers by Modification with Titanium Oxide Cluster Composite Nanoparticles The specific preparation steps are as follows: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 4000 cps, add 4.2 g of silica nanoparticles to it, and stir at 550 r / min for 5 min to mix evenly.

[0059] 2) Add 5 g of methyltrimethoxysilane to the above reaction system and continue stirring at 550 r / min for 5 min to mix thoroughly.

[0060] 3) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0061] 4) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0062] The TGA curves of the organosilicon elastomers prepared by this method are as follows: Figure 4 As shown, its collapse temperature is 462℃.

[0063] Example 5: Preparation of High-Temperature Resistant Organosilicon Elastomers by Modification with Titanium Oxide Cluster Composite Nanoparticles The specific preparation steps are as follows: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 4000 cps, add 4.2 g of silica nanoparticles to it, and stir at 550 r / min for 5 min to mix evenly.

[0064] 2) Add 10g of phenyltriethoxysilane to the above reaction system and continue stirring at 550r / min for 5min to mix thoroughly.

[0065] 3) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0066] 4) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0067] The TGA curves of the organosilicon elastomers prepared by this method are as follows: Figure 5 As shown, its collapse temperature is 393℃.

[0068] Example 6: Preparation of High-Temperature Resistant Organosilicon Elastomers by Modification with Titanium Oxide Cluster Composite Nanoparticles The specific preparation steps are as follows: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 1000 cps, add 4.2 g of silica nanoparticles to it, and stir at 550 r / min for 5 min to mix evenly.

[0069] 2) Add 10g of methyltrimethoxysilane to the above reaction system and continue stirring at 550r / min for 5min to mix thoroughly.

[0070] 3) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0071] 4) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0072] The TGA curves of the organosilicon elastomers prepared by this method are as follows: Figure 6 As shown, its collapse temperature is 458℃.

[0073] Comparative Example 1 Unlike Example 1, the silica was replaced with hydrophobic silica from Shanghai Yuanjiang Chemical Co., Ltd.

[0074] Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 4000 cps, add 4.2 g of hydrophobic silica nanoparticles and stir until homogeneous. Then add 10 g of methyltrimethoxysilane and stir at 550 r / min for 5 min. Next, add 0.1 mL of stannous octoate and 0.2 mL of KH550, and continue stirring at 550 r / min for 10 min to ensure thorough mixing. Degas under vacuum and allow to stand for curing.

[0075] The initial tensile strength measured with a tensile tester was 1.1 MPa. Clearly, the use of different types of silica will affect the tensile properties.

[0076] Comparative Example 2 Unlike Example 2, the viscosity of the methyl-terminated silicone oil used was changed to 2000 cps. Specific steps included: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 2000 cps, add 4.2 g of ultrafine hydrophobic silica (A-100) to it, and stir at 550 r / min for 5 min to mix evenly.

[0077] 2) Add 10g of methyltrimethoxysilane to the above reaction system and continue stirring at 550r / min for 5min to mix thoroughly.

[0078] 3) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0079] 4) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0080] Experiments confirmed that the curing time at room temperature was more than one week, and the tensile strength was 0.51 MPa. In terms of performance, the viscosity of 2000 cps was significantly worse than that of 1000 cps and 4000 cps.

[0081] Comparative Example 3 Unlike Example 2, the viscosity of the methyl-terminated hydroxyl silicone oil used was changed to 20000 cps. Specific steps included: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 20000 cps, add 4.2 g of ultrafine hydrophobic silica (A-100) to it, and stir at 550 r / min for 5 min to mix evenly.

[0082] 2) Add 10g of methyltrimethoxysilane to the above reaction system and continue stirring at 550r / min for 5min to mix thoroughly.

[0083] 3) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0084] 4) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0085] Experiments have shown that it is difficult to cure. Therefore, high-viscosity methyl-terminated hydroxyl silicone oils should not be used.

[0086] Comparative Example 4 Unlike Example 2, the addition of silica nanoparticles is omitted. The specific steps are as follows: The specific preparation steps are as follows: 1) Take 21 g of methyl-terminated hydroxyl silicone oil with a viscosity of 4000 cps, add 10 g of methyltrimethoxysilane to it, and stir at 550 r / min for 5 min to mix thoroughly.

[0087] 2) Weigh 100mg of titanium oxide clusters (Ti 12 The solid was placed in a reagent bottle, and 1 mL of chloroform was added. The mixture was sonicated until fully dissolved. The resulting solution was 100 mg / mL of titanium oxide clusters (Ti). 12 A chloroform solution.

[0088] 3) Add 1 mL of the above-mentioned titanium oxide cluster (Ti) to the reaction system in step 1). 12 Add the solution and stir thoroughly until homogeneous. Then add 0.1 mL of stannous octoate and 0.2 mL of KH550 respectively, and continue stirring at 550 r / min for 10 min to mix thoroughly. Degas under vacuum and allow to stand for reaction and solidification.

[0089] The organosilicon elastomer prepared by this method has a collapse temperature of 437℃ and a tensile strength of 1.51 MPa. Thermogravimetric curves are shown below. Figure 7 As shown.

[0090] Comparative Example 5 Example 7 of the inventor's previous patent CN 115490863 B also disclosed a method for preparing high-temperature resistant organosilicon elastomers using titanium oxide cluster nanoparticles. The specific preparation steps are as follows: 1) Weigh 200 mg of titanium oxide cluster solid (preparation process: first mix 1.05 mmol propionic acid with 2 ml ethylene glycol, then add 0.5 mmol isopropyl titanate, stir for 5 minutes, transfer the above mixture to a pressure-resistant bottle, seal, heat and stir at 100℃ for 24 hours, colorless crystals are generated. After removing the crystals, wash three times with a small amount of anhydrous tetrahydrofuran, and dry under vacuum at room temperature to obtain titanium oxide cluster nanoparticles) and place it in a reagent bottle. Add 2 mL of dichloromethane and sonicate until fully dissolved. The resulting solution is a 100 mg / mL dichloromethane solution of titanium oxide clusters.

[0091] 2) Take 10g of methyl-terminated hydroxyl silicone oil with a viscosity of 700cp, add 0.85g of trimethoxyphenylsilane and 2mL of the above titanium oxide cluster solution, and stir thoroughly until homogeneous. In this solution, the trimethoxyphenylsilane accounts for 8% of the mass fraction of the hydroxyl silicone oil, and the titanium oxide cluster accounts for 2% of the mass fraction of the hydroxyl silicone oil.

[0092] 3) Add 0.1 mL of stannous octoate and 0.2 mL of KH550 to the above solution, mix well, and allow to stand for the reaction to solidify.

[0093] The high-temperature resistant silicone elastomer prepared in this comparative example has a collapse temperature of 440℃, but its mechanical tensile strength is only 1.97 MPa.

[0094] The standards Q / JHY-017 GS-400 automotive external weld sealant, T / CAAMTB_03-2019 automotive rubber and plastic sealing strips, and QCT 639-2004 automotive rubber sealing strips all require a tensile strength ≥ 2.5 MPa. Therefore, the mechanical tensile strength of 1.97 MPa in the high-temperature resistant silicone elastomer provided in Comparative Example 5 is slightly lower.

[0095] Surface drying time: determined according to Method B in GB / T 13477.5-2002 Test Methods for Building Sealing Materials Part 5: Determination of Surface Drying Time.

[0096] Tensile strength: Refer to GB / T 528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber.

[0097] UV aging yellowing grade: Referencing the standard GB / T 14522-2008 "Artificial Climate Aging Test Method for Plastics, Coatings and Rubber Materials for Mechanical Industry Products - Fluorescent Ultraviolet Lamp", the UV aging light source is a UVB-313 lamp with an irradiance of 0.71 W / m². 2 The temperature was 60℃, the humidity was 50%, and the cycle was 168 hours. After aging, observe whether it turns yellow and compare it with the calibration card according to the degree of yellowing. Level 1 is the highest, indicating no color difference, and level 5 is the lowest, indicating complete yellowing.

[0098] Hardness: Refer to GB / T 531.1-2008 Test method for indentation hardness of vulcanized rubber or thermoplastic rubber - Part 1: Shore hardness test (Shore hardness) and use a type A Shore hardness tester for determination.

[0099] To more intuitively study the color change of the high-temperature resistant silicone elastomer in air at a certain temperature, the silicone elastomer prepared in Example 2 was placed in a constant temperature drying oven at 200°C for 2 hours. The comparison results are as follows: Figure 8 As shown in the figure. This indicates that the organosilicon elastomer prepared by the present invention does not change color at high temperatures (180~220℃) and for a relatively long time (1~3h) in air, indicating that it has a certain degree of tolerance.

[0100] Table 1

[0101] Table 1 shows that, through comparison of various examples, it was found that the tensile strength of organosilicon elastomers is related to the viscosity of hydroxyl silicone oil, the type and amount of monomer crosslinking agent, the amount of silica, and the amount of Ti. 12 The use of these components is closely related. Under the same conditions: 4000 cps hydroxyl silicone oil has a better curing effect; methyltrimethoxysilane is more suitable for this system than phenyltrimethoxysilane, especially when the amount of methyltrimethoxysilane accounts for approximately 50% of the mass of 4000 cps hydroxyl silicone oil; ultrafine hydrophobic silica A-100 can indeed play a reinforcing role and can effectively improve the tensile strength of organosilicon elastomers (Comparative Example 4 and Examples 2 and 3); Ti 12 The addition of [a specific ingredient] also improved the tensile strength to some extent (Examples 1 and 2); Example 2 is the optimal formulation for obtaining tensile strength. In addition, Example 2 showed a UV aging resistance to yellowing of 0, indicating strong resistance to yellowing after UV aging; moreover, its hardness and surface drying time were also excellent. These characteristics stem from the combination of ultrafine hydrophobic silica A-100 and Ti [a specific ingredient]. 12 The result of synergy.

[0102] The above description is merely a preferred embodiment of the present invention and is not intended to limit the 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 scope of protection of the present invention.

Claims

1. A high-temperature resistant organosilicon elastomer with high mechanical properties, characterized in that, The raw materials include hydroxyl silicone oil, silica nanoparticles, silane monomer crosslinking agent, silane coupling agent, and stannous octoate; The molar ratio of hydroxyl silicone oil, silane coupling agent and stannous octoate is 1:(1.2~2):(0.2~1); The mass of silica nanoparticles is 5-20% of that of hydroxyl silicone oil; The mass of the silane monomer crosslinking agent is 20-50% of that of the hydroxyl silicone oil.

2. The high-temperature resistant organosilicon elastomer according to claim 1, characterized in that, The mass of the silica nanoparticles is 10-20% of the hydroxyl silicone oil, preferably 18-20%. Preferably, the silica nanoparticles are fumed silica, and more preferably ultrafine hydrophobic silica A-100; Preferably, the silane coupling agent is KH550.

3. The high-temperature resistant organosilicon elastomer according to claim 1, characterized in that, It also includes titanium oxide cluster nano-additives, wherein the titanium oxide clusters are cage-like titanium oxide cluster molecules; Preferably, the titanium oxide cluster is a cage-like titanium oxide cluster molecule with 12 Ti elements. 12 O 16 (OPr i ) 16 Its outermost ring has 16 alkoxy groups and i PrO - Anions, among which, i PrO - It is an abbreviation for deprotonated isopropanol.

4. The high-temperature resistant organosilicon elastomer according to claim 3, characterized in that, The mass of the titanium oxide cluster nano-additive is 0.1-1% of the hydroxyl silicone oil, preferably 0.4-0.6%.

5. The high-temperature resistant organosilicon elastomer according to claim 1, characterized in that, The hydroxyl silicone oil is a methyl-terminated hydroxyl silicone oil with a viscosity of 800~4500 cps, preferably 800~1200 cps or 3500~4500 cps, and more preferably 800~1200 cps or 3800~4200 cps.

6. The high-temperature resistant organosilicon elastomer according to claim 1, characterized in that, The silane monomer crosslinking agent is one of methyltrimethoxysilane or phenyltriethoxysilane, preferably methyltrimethoxysilane; Preferably, the mass of the silane monomer crosslinking agent is 45-50% of the hydroxyl silicone oil.

7. A method for preparing a high-temperature resistant organosilicon elastomer with high mechanical properties as described in any one of claims 1 to 6, characterized in that, Includes the following steps: First, thoroughly mix hydroxyl silicone oil with silica nanoparticles and stir until homogeneous. Then, add silane monomer crosslinking agent and stir until homogeneous. Next, add silane coupling agent and stannous octoate and allow to stand for curing.

8. The preparation method according to claim 7, characterized in that, First, thoroughly mix hydroxyl silicone oil with silica nanoparticles and stir until homogeneous. Then, add silane monomer crosslinking agent and stir until homogeneous. Next, add titanium oxide cluster nano additives, and finally add silane coupling agent and stannous octoate. Allow to stand and cure.

9. The preparation method according to claim 7 or 8, characterized in that, After adding stannous octoate and silane coupling agent, the stirring speed is 400~600 r / min and the stirring time is 5~20 min; Preferably, vacuum degassing is performed before static curing, and preferably, vacuum degassing lasts for 5 to 20 minutes.

10. The application of a high-temperature resistant organosilicon elastomer with high mechanical properties as described in any one of claims 1 to 6, or a high-temperature resistant organosilicon elastomer with high mechanical properties prepared by the preparation method described in any one of claims 7 to 9, in the fields of 3D printing, electronics and electrical engineering, intelligent robots, aerospace, automobiles, medical, and construction.

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