Organosilicon polymer, preparation method thereof and ablation-resistant rubber

Abstract

The invention discloses an organic silicon polymer which has a structure shown in a formula 1, and in the formula 1, R and R1 are respectively and independently alkyl with the carbon number of 1-10; and n is an integer from 1 to 10. A POSS structure is introduced into a molecular structure, the preparation method is simple, the yield is high, the silicon rubber has enhancement and ablation resistance effects, theoretically, the addition amount of POSS can be unlimited in a cross-linked grid of silicon rubber, and particularly, spherical nano-particles POSS can be uniformly introduced, so that the silicon rubber can be used for preparing the silicon rubber. Meanwhile, the boron phenolic resin is added and has a synergistic effect with other components of the formula, so that the ablation resistance is improved, and the density is also reduced.

Description

Technical Field

[0001] The present application relates to the technical field of rubber, and particularly relates to an organosilicon polymer, a preparation method thereof, and an ablative-resistant rubber. Background Art

[0002] As a currently widely used sealing material, in addition to requiring excellent flame retardancy, higher requirements are also put forward for the flame impact resistance of the silicone rubber. It is required that the material is not burned through under the flame impact at extremely high temperatures, and can form a carbonized heat-insulating layer to protect the back components from being damaged by the impact of strong heat. At the same time, it is also required to have higher strength to ensure that it is not damaged during use.

[0003] There are many foreign research reports on the study of fireproof and ablative-resistant silicone rubber. Most add various heat-insulating fillers to the silicone rubber. For example, Khristopher of Dow Corning adds 7% - 20% wollastonite and 10% - 60% reinforcing fillers to liquid silicone rubber, and makes a test piece with a thickness of 0.635 cm and burns it under the flame of a Bunsen burner at 1093 °C for 15 minutes, and the back is not burned through or burned. A kind of lightweight fireproof layer for engines designed by John Meaney coats the first layer of silicone sealant on the surface of metal components. When it is not vulcanized, a ceramic fiber fabric is laid on it, and then the second layer of silicone sealant is coated. The silicone sealant uses Dow Corning 902006 space sealant, and the ceramic fiber cloth uses the product of 3M Company's Nextel 312 series. This thermal protection layer does not burn through under the 1093 °C flame for 15 minutes, but there are problems such as its relatively thick product, large specific gravity, and short fire resistance time.

[0004] Research shows that adding polyhedral oligomeric silsesquioxane (POSS) nanoparticles to silicone rubber can improve the ablative resistance of silicone rubber. However, when the addition amount of POSS particles in silicone rubber is too much, they will agglomerate, thus affecting its ablative resistance.

[0005] Therefore, developing an organosilicon polymer containing a POSS structure and adding it to silicone rubber to improve the ablative resistance is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present application provides an organosilicon polymer with simple preparation and high yield. When added to silicone rubber, it not only reduces the density but also has excellent ablative resistance.

[0007] The present application provides an organosilicon polymer having the structure of Formula 1:

[0008]

[0009] Wherein, R, R1 Each independently is an alkyl group having 1 to 10 carbon atoms; n is an integer from 1 to 10.

[0010] In some specific embodiments, R, R 1 Each independently is an alkyl group having 1 to 5 carbon atoms; n is an integer from 1 to 5.

[0011] In some specific embodiments, the organosilicon polymer has the structure of Formula 2;

[0012]

[0013] In some specific embodiments, the number-average molecular weight of the organosilicon polymer is 9,000 to 40,000.

[0014] This application also provides a method for preparing an organosilicon polymer, including:

[0015] Reacting a compound of Formula 3 with a compound of Formula 4 to obtain a compound of Formula 5;

[0016]

[0017] Reacting the compound of Formula 5 with a compound of Formula 6 to obtain an organosilicon polymer. The reaction route is as follows:

[0018]

[0019] This application first polymerizes tetramethoxysilane or trimethoxyethoxysilane, a catalyst, and a solvent to obtain a compound of Formula 3. In some specific embodiments, the temperature of the polymerization reaction is 80 °C to 100 °C, and the time of the polymerization reaction is 10 h to 20 h. In some specific embodiments, the solvent includes, but is not limited to, acetone and / or methanol. This application has no special requirements for the selection of the solvent, and acetone and methanol are preferred, with a volume ratio of 88:12. In some specific embodiments, the catalyst includes, but is not limited to, lithium hydroxide monohydrate. This application has no special requirements for the selection of the catalyst. In some specific embodiments, the mass ratio of the catalyst to tetramethoxysilane or trimethoxyethoxysilane is (3 - 5):(40 - 50). In some specific embodiments, after the polymerization reaction, acidification, filtration, washing, and vacuum drying are carried out to obtain a compound of Formula 3. In some specific embodiments, the acidification is carried out using dilute hydrochloric acid, and the filtration is carried out using water. In some specific embodiments, the temperature of the vacuum drying is 30 °C to 50 °C, and the time of the vacuum drying is 40 h to 50 h.

[0020] The present application then reacts the compound of formula 3 with the compound of formula 4 in an organic solvent to obtain a compound of formula 5. In some specific implementations, the molar ratio of the compound of formula 3 to the compound of formula 4 is (0.8-1.2): (1.8-2.2). In some specific implementations, the temperature of the reaction is 55°C to 80°C, preferably 65°C. In some specific implementations, the reaction time is 8h to 15h, preferably 10h. In some specific implementations, the reaction of the compound of formula 3 with the compound of formula 4 is carried out in the presence of triethylchlorosilane.

[0021] The present application then reacts the compound of formula 5 and the compound of formula 6 with triethylchlorosilane in a solvent to obtain a compound of formula 5. In some specific implementations, the molar ratio of the compound of formula 5 and the compound of formula 6 to triethylchlorosilane is (0.8-1.2): (0.8-1.2): (0.5-2). In some specific implementations, the temperature of the reaction is 55°C to 80°C, preferably 65°C. In some specific implementations, the reaction time is 8h to 15h, preferably 10h. In some specific implementations, the reaction is followed by reduced pressure distillation to remove the solvent, and vacuum drying to obtain an organosilicon polymer. In some specific implementations, the solvent includes but is not limited to toluene, and the present application has no special requirements for the selection of solvents.

[0022] The present application also provides an ablation-resistant silicone rubber, comprising the above-mentioned organosilicon polymer or the organosilicon polymer prepared by the above-mentioned preparation method.

[0023] In some specific implementations, the ablation-resistant silicone rubber includes, by mass, 30 to 50 parts of the first component, 30 to 50 parts of the second component, 20 to 70 parts of boron phenolic resin, 2 to 5 parts of zirconium oxide and rare earth doped oxide hollow ceramic microspheres, 1 to 3 parts of iron red, 3 to 5 parts of fumed silica, and 2 to 3 parts of azodicarbonamide. In some specific implementations, the ablation-resistant silicone rubber has a thickness of 2 mm to 5 mm.

[0024] The ablation-resistant silicone rubber described in the present application includes a first component. In some specific implementations, the first component includes, by mass, 30 to 80 parts of an organic silicon polymer and 10 to 30 parts of methyl vinyl silicone oil, the mass fraction of the organic silicon polymer is 30 to 80 parts, which can be 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 parts, and the mass fraction of the methyl vinyl silicone oil is 10 to 30 parts, which can be 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 parts. The mass fraction of the first component is 30 to 50 parts, which can be 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50 parts.

[0025] The ablation-resistant silicone rubber described in the present application includes a second component. In some specific implementations, the second component includes, by mass, 5 to 10 parts of a Pt catalyst and 5 to 20 parts of a hydrogen-containing organic silicone oil, wherein the mass fraction of the Pt catalyst is 5 to 10 parts, which may be 5, 6, 7, 8, 9, or 10 parts, and the mass fraction of the hydrogen-containing organic silicone oil is 5 to 20 parts, which may be 5, 6, 7, 8, 10, 12, 15, 16, 18, or 20 parts. The mass fraction of the second component is 30 to 50 parts, which may be 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, or 50 parts.

[0026] The ablation-resistant silicone rubber described in the present application includes boron phenolic resin. The mass fraction of the boron phenolic resin is 20 to 70 parts, which can be 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, and 70 parts.

[0027] The ablation-resistant silicone rubber described in the present application includes hollow ceramic microspheres of zirconium oxide and rare earth doped oxides. In some specific implementations, the particle size of the hollow ceramic microspheres of zirconium oxide and rare earth doped oxides is 120 μm to 180 μm. The mass fraction of the hollow ceramic microspheres of zirconium oxide and rare earth doped oxides is 2 to 5 parts, which can be 2 parts, 3 parts, 4 parts, or 5 parts.

[0028] The ablation-resistant silicone rubber described in the present application includes iron red, and the mass fraction of the iron red is 1 to 3 parts, which can be 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts.

[0029] The ablation-resistant silicone rubber described in the present application includes fumed silica. The mass fraction of the fumed silica is 3 to 5 parts, and can be 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts.

[0030] The ablative-resistant silicone rubber described in this application includes azodicarbonamide. The mass fraction of the azodicarbonamide is 2 to 3 parts, and it can be 2 parts, 2.5 parts, or 3 parts.

[0031] This application also provides a preparation method for ablative-resistant silicone rubber, including:

[0032] Mix the above-mentioned organosilicon polymer or the organosilicon polymer prepared by the above-mentioned preparation method with methyl vinyl silicone oil to obtain the first component, and mix the Pt catalyst with hydrogen-containing organosilicon oil to obtain the second component;

[0033] Mix the first component, the second component, boron phenolic resin, zirconia, rare earth-doped oxide hollow ceramic microspheres, iron oxide red, fumed silica, and azodicarbonamide to obtain ablative-resistant silicone rubber.

[0034] In some specific implementation manners, after the first component, the second component, boron phenolic resin, zirconia, rare earth-doped oxide hollow ceramic microspheres, iron oxide red, fumed silica, and azodicarbonamide are mixed and pressurized and left standing, ablative-resistant silicone rubber is obtained. In some specific implementation manners, the pressurization conditions are 25°C ± 5°C, relative humidity 55% ± 5%, the pressurization pressure is 5 - 10 MPa, and the standing time is 48 h - 150 h.

[0035] This application introduces a POSS structure into the molecular structure. The preparation method is simple and has a high yield. It has the functions of enhancing and anti-ablative properties itself. Moreover, theoretically, the addition amount of POSS in the crosslinked network of silicone rubber can be unrestricted. In particular, spherical nanoparticles of POSS can be uniformly introduced. At the same time, the addition of boron phenolic resin and other components of the formula play a synergistic role, not only improving the anti-ablative ability but also reducing the density. Description of the Drawings

[0036] Figure 1 1H NMR spectrum of the organosilicon polymer provided in Example 1 of this application;

[0037] Figure 2 Infrared spectrum of the organosilicon polymer provided in Example 1 of this application;

[0038] Figure 3 Ablation back temperature change curve of the ablative-resistant silicone rubber provided in Example 2 of this application. Detailed Description of the Invention

[0039] It should be understood that the expression "one or more of..." individually includes each of the recited objects following the expression and various different combinations of two or more of the recited objects, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited objects should be understood to have the same meaning, unless otherwise understood from the context.

[0040] The terms "comprising", "having" or "containing", including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unrecited elements or steps, unless specifically stated otherwise or otherwise understood from the context.

[0041] It should be understood that as long as the present application remains operable, the order of steps or the order of performing certain actions is not important. In addition, two or more steps or actions can be performed simultaneously.

[0042] The use of any and all examples or exemplary language such as "for example" or "including" in this application is merely intended to better illustrate the application and does not limit the scope of the application unless a claim is made. No language in this specification should be construed as indicating that any unclaimed element is essential for the practice of the application.

[0043] In addition, the numerical ranges and parameters used to define the present application are approximate values. The relevant values in the specific embodiments have been presented as precisely as possible herein. However, any value inherently and inevitably contains standard deviations due to individual testing methods. Therefore, unless otherwise clearly stated, it should be understood that all ranges, quantities, values and percentages used in this disclosure are modified by "about". Here, "about" generally means that the actual value is within plus or minus 10%, 5%, 1% or 0.5% of a specific value or range.

[0044] The present application provides a silicone polymer having the structure of Formula 1:

[0045]

[0046] Wherein, R, R 1 are each independently an alkyl group having 1 to 10 carbon atoms; n is an integer from 1 to 10. The POSS structure is introduced into the molecular structure of the present application. The preparation method is simple and the yield is high. It has the functions of enhancing and anti-ablative properties. Moreover, theoretically, the addition amount of POSS in the crosslinked network of silicone rubber can be unrestricted. In particular, the spherical nanoparticles of POSS can be uniformly introduced, which cannot be achieved by other inorganic solid particle fillers. At the same time, the addition of boron phenolic resin and other components of the formula play a synergistic role, not only improving the anti-ablative ability but also reducing the density.

[0047] The present application will be further described below in conjunction with embodiments. The protection scope of the present application is not limited by the following embodiments.

[0048] Example 1

[0049] This example provides a silicone polymer having a structure of Formula 1. The preparation method of the silicone polymer includes:

[0050] Weigh 3.3 g of lithium hydroxide monohydrate as a catalyst and 1.27 g of deionized water (total water volume of 2.67 g) and place them in a 500 mL three-necked flask. Add 165 mL of a mixed solvent of acetone and methanol (volume ratio of 44:6), and protect with nitrogen. Slowly add 46 g of tetramethoxysilane, then heat up to 85 °C. After stirring and reacting for 16 h, stop heating, cool to room temperature, add 350 mL of dilute hydrochloric acid (mass concentration 3%) for acidification, and stir and react for 4 h; after the acidification treatment, stop the reaction, perform suction filtration, wash the product with water until neutral, and then wash it three times with acetone to obtain a yellow solid. Then dry it in vacuo at 35 °C for 48 h to obtain a compound with a structure of Formula 3.

[0051] At room temperature, dissolve 100 g of the compound with a structure of Formula 3 and 600 g of commercially available dimethyldimethoxysilane in 1000 mL of toluene and stir evenly. Heat the reaction system to 65 °C. After reacting for 10 h, distill off toluene under reduced pressure, and then dry it in vacuo for 48 h to obtain a compound with a structure of Formula 5.

[0052] At 65 °C, mix and react the compound with a structure of Formula 5 and the compound with a structure of Formula 6 in toluene at a molar ratio of 0.8:0.9 for 10 h. Distill off the solvent under reduced pressure and dry it in vacuo to obtain a silicone polymer with a yield of 62%.

[0053] Perform a nuclear magnetic resonance hydrogen spectrum test on the obtained silicone polymer. The nuclear magnetic resonance hydrogen spectrum is as shown in Figure 1 shown; perform an infrared spectrum test on the obtained silicone polymer. The infrared spectrum is as shown in Figure 2 shown.

[0054] Example 2

[0055] This example provides an ablative-resistant silicone rubber, which includes 50 parts of a first component, 50 parts of a second component, 20 parts of boron phenolic resin, 5 parts of zirconia and rare earth-doped oxide hollow ceramic microspheres, 3 parts of iron oxide red, 5 parts of fumed silica and 3 parts of azodicarbonamide; the first component includes, by mass, 80 parts of a silicone polymer and 20 parts of methyl vinyl silicone oil; the second component includes, by mass, 80 parts of Pt as the main catalyst and 5 parts of hydrogen-containing silicone oil.

[0056] The preparation method of the ablative-resistant silicone rubber includes:

[0057] 1) Put boron phenolic resin, zirconia, rare earth-doped oxide hollow ceramic microspheres, iron oxide red, fumed silica, and azodicarbonamide into a forced-air drying oven and dry at 110°C for 6 hours;

[0058] 2) Preparation of the first component: Mix the organosilicon polymer and methyl vinyl silicone oil evenly;

[0059] 3) Preparation of the second component: Mix the Pt-based main catalyst and hydrogen-containing organosilicon oil evenly;

[0060] 4) Add the first component, the second component, boron phenolic resin, zirconia, rare earth-doped oxide hollow ceramic microspheres, iron oxide red, fumed silica, and azodicarbonamide to a three-roll mill and grind and knead for 10 - 15 minutes until the powder filler has no agglomerated particles and is completely mixed evenly with the matrix silicone rubber;

[0061] 5) Put the evenly mixed rubber compound into a mold, apply a pressure of 5 - 10 MPa in a standard environment (25°C ± 5°C, relative humidity 55% ± 5), let it stand for 48 hours, take out the film and let it stand for another 72 hours in the standard environment to obtain a silicone rubber (film) with a thickness of about 3.2 mm that is resistant to ablation. Conduct an ablation back temperature test on the obtained ablation-resistant rubber, and the ablation back temperature change curve is as Figure 3 shown.

[0062] Example 3

[0063] This example provides a silicone rubber resistant to ablation, which comprises 50 parts of the first component, 50 parts of the second component, 30 parts of boron phenolic resin, 2 parts of zirconia and rare earth-doped oxide hollow ceramic microspheres, 1 part of iron oxide red, 3 parts of fumed silica, and 2 parts of azodicarbonamide; the first component includes, by mass fraction, 30 parts of organosilicon polymer and 30 parts of methyl vinyl silicone oil; the second component includes, by mass fraction, 20 parts of Pt-based main catalyst and 20 parts of hydrogen-containing organosilicon oil. The preparation method of the silicone rubber resistant to ablation is the same as that of Example 2.

[0064] Example 4

[0065] This example provides a silicone rubber resistant to ablation, which comprises 50 parts of the first component, 50 parts of the second component, 40 parts of boron phenolic resin, 3 parts of zirconia and rare earth-doped oxide hollow ceramic microspheres, 1 part of hollow phenolic microspheres, 2 parts of iron oxide red, 4 parts of fumed silica, and 3 parts of azodicarbonamide; the first component includes, by mass fraction, 70 parts of organosilicon polymer and 30 parts of methyl vinyl silicone oil; the second component includes, by mass fraction, 70 parts of Pt-based main catalyst and 15 parts of hydrogen-containing organosilicon oil. The preparation method of the silicone rubber resistant to ablation is the same as that of Example 2.

[0066] Example 5

[0067] This embodiment provides an ablative-resistant silicone rubber, which comprises 50 parts of a first component, 50 parts of a second component, 50 parts of boron phenolic resin, 3 parts of zirconia and rare earth-doped oxide hollow ceramic microspheres, 1 part of iron red, 2 parts of fumed silica and 3 parts of azodicarbonamide; the first component comprises, by mass fraction: 70 parts of organosilicon polymer and 25 parts of methyl vinyl silicone oil; the second component comprises, by mass fraction: 80 parts of Pt as the main catalyst and 10 parts of hydrogen-containing organosilicon oil. The preparation method of the ablative-resistant silicone rubber is the same as that of Example 2.

[0068] Perform performance tests on the ablative-resistant silicone rubbers provided in Examples 2-5. The test methods are as follows:

[0069] Tensile strength: GB / T 528;

[0070] Pot life: HB 5241;

[0071] Specific gravity: GB / T 533;

[0072] Shore A hardness after 14 days: GB / T 531;

[0073] Heat resistance to cracking: 0.069 MPa, 30 minutes;

[0074] Shear strength: HB 5250;

[0075] Fireproof performance: Flame temperature 1050°C - 1100°C, combustion time 15 min;

[0076] Peel strength: HB 5249;

[0077] Heat insulation performance: After the fireproof test (1093°C × 15 min), the heat insulation performance is equivalent to that of the FASTBLOCKTM301 lightweight fireproof sealant of the American TA Company (±20°C). The test results are shown in Table 1.

[0078] Table 1

[0079]

[0080] As can be seen from Table 1, introducing the POSS structure into the molecular structure has the functions of enhancing and ablative resistance. Moreover, theoretically, the addition amount of POSS in the crosslinked network of silicone rubber can be unrestricted. In particular, the spherical nanoparticles of POSS can be uniformly introduced, which cannot be achieved by other inorganic solid particle fillers. At the same time, the addition of boron phenolic resin and other components of the formula play a synergistic role, not only improving the ablative resistance but also reducing the density.

[0081] As described above, it is only the preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application, according to the technical solution and its application concept of the present application, makes equivalent replacements or changes, and should be covered within the protection scope of the present application.

Claims

1. An organosilicon polymer, characterized in that: It has the structure of formula 1: Wherein, R and R1 are each independently an alkyl group with 1 to 10 carbon atoms; and n is an integer from 1 to 10.

2. The organosilicon polymer according to claim 1, characterized in that R and R1 are each independently an alkyl group having 1 to 5 carbon atoms; n is an integer from 1 to 5.

3. The organosilicon polymer according to claim 1, characterized in that The organosilicon polymer has a structure of formula 2; 4. The organosilicon polymer according to claim 1, characterized in that The number average molecular weight of the organic silicon polymer is 9,000 to 40,000.

5. A method for preparing an organosilicon polymer, characterized in that: include: The compound of formula 3 is reacted with the compound of formula 4 to obtain the compound of formula 5; The compound of formula 5 is reacted with the compound of formula 6 to obtain an organosilicon polymer.

6. The preparation method according to claim 5, characterized in that: The reaction of the compound of formula 3 and the compound of formula 4 is carried out in the presence of triethylchlorosilane.

7. An ablation-resistant silicone rubber, characterized in that: The invention comprises the organosilicon polymer as claimed in claims 1 to 4 or the organosilicon polymer prepared by the preparation method as claimed in claim 5 or 6.

8. The ablation-resistant silicone rubber according to claim 7, characterized in that: The invention comprises, by mass, 30 to 50 parts of a first component, 30 to 50 parts of a second component, 20 to 70 parts of boron phenolic resin, 2 to 5 parts of zirconium oxide and hollow ceramic microspheres doped with rare earth oxides, 1 to 3 parts of iron oxide red, 3 to 5 parts of fumed silica and 2 to 3 parts of azodicarbonamide; the first component comprises, by mass, 30 to 80 parts of an organosilicon polymer and 10 to 30 parts of methyl vinyl silicone oil; the second component comprises, by mass, 5 to 10 parts of a Pt catalyst and 5 to 20 parts of hydrogen-containing organosilicon oil.

9. The ablation-resistant silicone rubber according to claim 8, characterized in that: The particle size of the zirconium oxide and rare earth doped oxide hollow ceramic microspheres is 120 μm to 180 μm.

10. A method for preparing ablation-resistant silicone rubber, characterized in that: include: The organic silicon polymer according to claims 1 to 4 or the organic silicon polymer prepared by the preparation method according to claim 5 or 6 is mixed with methyl vinyl silicone oil to obtain a first component, and the Pt catalyst is mixed with the hydrogen-containing organic silicon oil to obtain a second component; The first component, the second component, boron phenolic resin, zirconium oxide and rare earth doped oxide hollow ceramic microbeads, iron red, fumed silica and azodicarbonamide are mixed to obtain ablation-resistant silicone rubber.

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