Carborane modified heat-resistant silicone oil and preparation method thereof

Abstract

The invention belongs to the field of organic silicon materials, and particularly relates to carborane modified heat-resistant silicone oil and a preparation method thereof. The carborane modified heat-resistant silicone oil is prepared by introducing a molecular chain containing a benzene ring and carborane structure into a side chain of the silicone oil, and the heat resistance and radiation resistance of the hydrogen-containing silicone oil are remarkably improved by utilizing the synergistic effect of a cage structure of the benzene ring and carborane; the modified silicone oil can still keep good physical and chemical properties in high-temperature and radiation environments, the application range of the modified silicone oil in the high-temperature and radiation fields is expanded, the modified silicone oil rubber material containing a carborane structure can be further processed to be used in a thermal protection system of an aircraft, and the situation that the aircraft is prone to falling off in the high-speed flight process is prevented. And the material embrittlement and cracking are caused by violent friction between the surface of the aircraft body and air, so that the structural integrity of the aircraft is effectively protected.

Description

Technical Field

[0001] The invention belongs to the field of preparation of organic silicon materials, and particularly relates to a carborane-modified heat-resistant silicone oil and a preparation method thereof. Background Art

[0002] Silicone oil is an organic polysiloxane product that is liquid at room temperature. The bond energy of the silicon-oxygen bond (452kJ / mol) is higher than that of the carbon-carbon bond (347kJ / mol), which makes it difficult for the molecular chain of silicone oil to decompose under high temperature. It can maintain stable performance in a wide temperature range. General heat-resistant silicone oil can work normally in the temperature range of -50℃ to 200℃, while some high-performance heat-resistant silicone oil can even withstand high temperatures of up to 300℃. At such high temperatures, its viscosity changes little and there will be no obvious decomposition or carbonization.

[0003] However, in some extreme working conditions, such as when an aircraft engine is working, its internal temperature is extremely high, and the temperature in some areas, such as near the combustion chamber, can far exceed 400°C. As a lubricant, silicone oil needs to maintain good lubrication performance in such a high-temperature environment to reduce friction and wear between engine parts, ensure the efficient operation and reliability of the engine, or the high temperature generated by the friction between the protective materials on the surface of the aircraft and the air during high-speed flight. Traditional silicone oil cannot meet the requirements of these extreme working conditions, so it is necessary to improve the physical and chemical properties of silicone oil to enhance its heat resistance, radiation resistance and aging resistance in special application scenarios.

[0004] The current method for improving heat resistance is mainly to add heat-resistant fillers to silicone oil to form a blend. For example, patent CN102220004A discloses a heat-resistant silicone oil composite, which is prepared by blending and modifying silicone oil and metallocene-based silazane. While improving the heat-resistant oxidation performance of silicone oil, it reduces the thermal degradation of molecular chains and reduces the thermal weight loss of silicone oil, making silicone oil have better comprehensive heat resistance. However, physical blending modification will cause phase separation, insufficient interface strength, poor processing performance and decreased thermal stability during actual application. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a carborane-modified heat-resistant silicone oil, the general structural formula of which is as follows: The structural formula of the carborane-modified heat-resistant silicone oil is: ,in It is a long silicon chain.

[0006] In certain embodiments, the structural formula of the carborane-modified heat-resistant silicone oil is:

[0007]

[0008] Among them, x=50-100, y=400-500.

[0009] By introducing molecular chains containing benzene rings and carborane structures into the side chains of silicone oil, the heat resistance, radiation resistance, aging resistance and other properties of silicone oil are improved from the perspective of molecular structure, solving the requirements of most silicone oils and silicone rubbers that cannot be met in extreme applications, such as lubricating oils for aircraft engines and protective materials on the surface of aircraft bodies.

[0010] In some embodiments, the carborane-modified heat-resistant silicone oil first prepares 4-hydroxyphenyl carborane through the lithiation reaction and reduction reaction of ortho-carborane, then reacts it with halogenated olefins through a nucleophilic substitution reaction to generate a long-chain olefin carborane, and finally grafts it onto the side chain of hydrogenated silicone oil through a hydrosilylation reaction to form a block copolymer. The introduction of the 4-hydroxyphenyl carborane structure greatly improves the heat resistance and stability of the material. At the same time, due to the synergistic steric effect of the benzene ring and the carborane cage structure, the radiation resistance and aging resistance of the material are also greatly improved. The preparation method of the carborane-modified heat-resistant silicone oil comprises the following steps:

[0011] (1) Synthesis of 4-hydroxyphenylcarborane: In a nitrogen atmosphere, 1,2-carborane, anhydrous tetrahydrofuran and n-butyl lithium were mixed at 0-5 degrees Celsius, stirred and reacted for 1 hour, 4-iodoanisole was added at 25°C, the temperature was raised to 90°C and reacted for 24 hours, the residual solvent was removed by vacuum distillation, pyridinium hydrochloride was added, the temperature was 180°C, the reaction was continued for 5-6 hours, and the white powder 4-hydroxyphenylcarborane was obtained after washing with dilute hydrochloric acid solution and purification by column chromatography. The reaction was completed. The chemical reaction equation is as follows:

[0012]

[0013] (2) Synthesis of nonene carborane: N, N-dimethylformamide, 4-hydroxyphenyl carborane and halogenated nonene were mixed under nitrogen atmosphere, and then sodium hydroxide aqueous solution was added after sufficient stirring. The mixture was heated and stirred under reflux at 50°C for 8-10 hours. After the reaction was completed, the solvent and unreacted monomers were removed by rotary evaporation. The chemical reaction equation is as follows:

[0014]

[0015] Among them, R=Cl, Br, I.

[0016] (3) Synthesis of carborane-modified hydrogenated silicone oil: Add hydrogenated silicone oil to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, heat to 110°C, and evacuate to remove water for 1 hour; add the halogenated nonene carborane and chloroplatinic acid solution prepared in step (2) to a single-necked flask equipped with a magnetic stirrer, then heat to 70°C and activate evenly for 15 minutes; add the activated mixed solution dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, control the temperature in the four-necked flask at 120-130°C, and react at a constant temperature for 3-4 hours; after the reaction is completed, cool to 80°C, perform vacuum distillation, and gradually increase the temperature to 130°C. After the low-boiling substances are removed, cool to room temperature and discharge to obtain carborane-modified silicone oil. The chemical reaction equation is as follows:

[0017]

[0018] Preferably, the pyridinium hydrochloride in step (1) is one of 2-chloromethyl-3,4-dimethoxypyridine hydrochloride, 4-(chloromethyl)-2-methylpyridine hydrochloride and 2-chloromethylpyridine hydrochloride.

[0019] Preferably, the mass ratio of 1,2-carborane, anhydrous tetrahydrofuran, n-butyl lithium, 4-iodoanisole and pyridinium hydrochloride in step (1) is (8-9):(6-7):1:(11-12):(34-35).

[0020] Preferably, the halogenated olefin in step (2) is one of 9-chloro-1-nonene, 9-bromo-1-nonene and 9-iodo-1-nonene.

[0021] Preferably, the molar ratio of 4-hydroxyphenylcarborane to halononene in step (2) is 1:1.

[0022] Preferably, the mass concentration of the sodium hydroxide aqueous solution in step (2) is 10%, and the amount of the sodium hydroxide aqueous solution used is 1-1.5 times the molar mass of 4-hydroxyphenylcarborane.

[0023] Preferably, the molar ratio of the hydrogenated silicone oil to the halogenated nonene carborane in step (3) is 1:1.

[0024] Preferably, the chloroplatinic acid solution in step (3) is an isopropanol solution of chloroplatinic acid hexahydrate.

[0025] Preferably, the concentration of chloroplatinic acid in the reaction system of step (3) is 30-50 ppm.

[0026] Preferably, the hydrogen content of the hydrogen-containing silicone oil in step (3) is 0.8%.

[0027] The beneficial effects of the present invention are:

[0028] The present invention introduces a molecular chain containing a benzene ring and a carborane structure into the side chain of silicone oil to prepare carborane-modified heat-resistant silicone oil. Through the synergistic effect of the benzene ring and the carborane cage structure, on the one hand, the benzene ring and the carborane structure are used to absorb the energy of high-energy particles or photons generated during the radiation process, and convert them into vibration energy or heat energy inside the molecule, thereby reducing the direct effect of radiation energy on the silicone oil molecule and reducing the influence of radiation on the performance of the silicone oil. On the other hand, the interaction between the benzene ring and the carborane can also promote the transmission and transfer of energy within the molecule, so that the energy can be more evenly distributed throughout the molecule, avoiding the destruction of chemical bonds caused by excessive local energy, thereby improving the radiation resistance of the silicone oil. Not only can the heat resistance of the material be greatly improved, but it also has excellent radiation resistance and aging resistance, so that the material can be used in most extreme environments, and the various properties of the material can meet the needs of aeroengines, aircraft shells and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the infrared spectrum of the carborane-modified silicone oil in Example 1;

[0030] Figure 2 The thermogravimetric analysis spectra of the hydrogen-containing silicone oil and carborane-modified silicone oil (modified silicone oil) in Example 1 are shown in FIG. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] (1) Preparation of 4-hydroxyphenylcarborane:

[0034] Under nitrogen atmosphere, at 0 degrees Celsius, 8 g of 1,2-carborane, 6 g of anhydrous tetrahydrofuran and 1 g of n-butyl lithium were added to a three-necked flask equipped with a magnetic stirring device in sequence, and stirred for reaction for 1 hour. Then, 11 g of 4-iodoanisole was added at 25°C, and the temperature was raised to 90°C for reaction for 24 hours. The residual solvent was removed by vacuum distillation, and 34 g of 2-chloromethyl-3,4-dimethoxypyridine hydrochloride was added. The reaction was carried out at 180°C for 5 hours. After washing with a dilute hydrochloric acid solution and purification by column chromatography, 4-hydroxyphenylcarborane as a white powder was obtained, and the reaction was completed.

[0035] (2) Preparation of halogenated nonene carborane

[0036] Under a nitrogen atmosphere, 5 g of N,N-dimethylformamide, 2.4 g of 4-hydroxyphenylcarborane and 2 g of 9-chloro-1-nonene were added to a three-necked flask equipped with a stirring device and a condensing reflux device in sequence, and after sufficient stirring, 3 g of a 10% sodium hydroxide aqueous solution was added, and the mixture was heated and stirred at 50° C. for 10 hours under reflux conditions. After the reaction was completed, the solvent and unreacted monomers were removed by reduced pressure distillation to obtain halogenated nonene carborane;

[0037] (3) Preparation of carborane-modified silicone oil:

[0038] 25g of hydrogenated silicone oil (Foshan Huagu Organic Silicone Co., Ltd., model 0.8%, molecular weight 18000-20000) was added to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, and the temperature was raised to 110°C, and the water was removed by vacuum for 1h; 8.8g of the prepared halogenated nonene carborane and a 0.5g / L chloroplatinic acid solution were added to a single-necked flask equipped with a magnetic stirrer, and then the temperature was raised to 70°C and uniformly activated for 15min; the mixed solution after uniform activation for 15min was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, the temperature in the four-necked flask was controlled at 130°C, and the reaction was carried out at a constant temperature for 4h; after the reaction was completed, the temperature was lowered to 80°C, and the vacuum distillation was carried out, and the temperature was gradually raised to 130°C. After the low-boiling substances were removed, the material was cooled to room temperature and discharged to obtain carborane-modified silicone oil; the concentration of chloroplatinic acid in the reaction system was 30ppm.

[0039] like Figure 1 Infrared analysis shows a strong and broad absorption peak in the range of 2500-2600 cm-1, which is the characteristic absorption peak of boron-hydrogen bond, and 1440 cm -1 and 2910cm -1 The left and right sides are the characteristic peaks of methylene, 1000-1130cm -1 The strong absorption band that appears is the characteristic peak of Si-O-Si, 890cm -1 、1060cm -1 and 1210cm -1 The left and right are the characteristic peaks of Si-R, 890cm -1 It is the characteristic peak of the para-disubstituted benzene ring. The appearance of the above characteristic peaks indicates the successful introduction of the carborane group and the successful synthesis of the carborane-modified heat-resistant silicone oil.

[0040] like Figure 2 The thermogravimetric analysis spectrum shows that the initial decomposition temperature (Td 5％ ) is 269°C, and the initial decomposition temperature of the modified silicone oil after the introduction of carborane groups is 415°C, and the thermal stability is effectively improved.

[0041] Example 2

[0042] (1) Preparation of 4-hydroxyphenylcarborane: The difference from Example 1 is that 2-chloromethyl-3,4-dimethoxypyridine hydrochloride is changed to 4-(chloromethyl)-2-methylpyridine hydrochloride, and the rest is the same as Example 1;

[0043] (2) Preparation of halogenated nonene carborane: The difference from Example 1 is that 9-chloro-1-nonene is changed to 9-bromo-1-nonene, and the rest is the same as Example 1;

[0044] (3) Preparation of carborane-modified silicone oil: same as in Example 1.

[0045] Example 3

[0046] (1) Preparation of 4-hydroxyphenylcarborane: The difference from Example 1 is that 2-chloromethyl-3,4-dimethoxypyridine hydrochloride is changed to 2-chloromethylpyridine hydrochloride, and the rest is the same as Example 1;

[0047] (2) Preparation of halogenated nonene carborane: The difference from Example 1 is that 9-chloro-1-nonene is changed to 9-iodo-1-nonene, and the rest is the same as Example 1;

[0048] (3) Preparation of carborane-modified silicone oil: same as in Example 1.

[0049] Example 4

[0050] (1) Preparation of 4-hydroxyphenylcarborane:

[0051] In a nitrogen atmosphere, 9 g of 1,2-carborane, 7 g of anhydrous tetrahydrofuran and 1 g of n-butyl lithium were added to a three-necked flask equipped with a magnetic stirring device in sequence. After being fully stirred for 1 h, 12 g of 4-iodoanisole was added at 25 ° C. The temperature was raised to 90 ° C. and reacted for 24 h. The residual solvent was removed by vacuum distillation. 35 g of 2-chloromethyl-3,4-dimethoxypyridine hydrochloride was added and reacted at 180 ° C. for 5 h. After washing with a dilute hydrochloric acid solution and purification by column chromatography, 4-hydroxyphenylcarborane as a white powder was obtained, and the reaction was completed.

[0052] (2) Preparation of halogenated nonene carborane:

[0053] Under a nitrogen atmosphere, 10 g of N,N-dimethylformamide, 5.2 g of the prepared 4-hydroxyphenyl carborane and 4.4 g of 9-chloro-1-nonene were added to a three-necked flask equipped with a stirring device and a condensing reflux device in sequence, and after sufficient stirring, 6 g of a 10% sodium hydroxide aqueous solution was added, and the mixture was heated and stirred at reflux at 50° C. for 10 hours. After the reaction was completed, the solvent and unreacted monomers were removed by rotary evaporation to obtain halogenated nonene carborane;

[0054] (3) Preparation of carborane-modified silicone oil:

[0055] 38 g of hydrogenated silicone oil was added to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, and the temperature was raised to 110° C., and the water was removed by vacuum for 1 hour; 13.2 g of the prepared halogenated nonene carborane and a 0.5 g / L chloroplatinic acid solution were added to a single-necked flask equipped with a magnetic stirrer, and then the temperature was raised to 70° C. and uniformly activated for 15 minutes; the mixed solution of halogenated nonene carborane and chloroplatinic acid after uniform activation for 15 minutes was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, the temperature in the four-necked flask was controlled at 130° C., and the reaction was carried out at a constant temperature for 4 hours; after the reaction was completed, the temperature was lowered to 80° C., vacuum distillation was performed, and the temperature was gradually increased to 130° C. After the low-boiling substances were removed, the material was cooled to room temperature and discharged to obtain carborane-modified silicone oil; the concentration of chloroplatinic acid in the reaction system was 40 ppm.

[0056] Example 5

[0057] (1) Preparation of 4-hydroxyphenylcarborane:

[0058] In a nitrogen atmosphere, 8.5 g of 1,2-carborane, 6.5 g of anhydrous tetrahydrofuran and 1 g of n-butyl lithium were added to a three-necked flask equipped with a magnetic stirring device in sequence. After being fully stirred for 1 h, 11.5 g of 4-iodoanisole was added at 25°C, the temperature was raised to 90°C and the reaction was carried out for 24 h. The residual solvent was removed by distillation under reduced pressure, and 35 g of 2-chloromethyl-3,4-dimethoxypyridine hydrochloride was added. The reaction was carried out at 180°C for 5 h. After washing with a dilute hydrochloric acid solution and purification by column chromatography, 4-hydroxyphenylcarborane as a white powder was obtained, and the reaction was completed.

[0059] (2) Preparation of halogenated nonene carborane

[0060] Under nitrogen atmosphere, 15 g of N,N-dimethylformamide, 7.2 g of the prepared 4-hydroxyphenyl carborane and 6 g of 9-chloro-1-nonene were added to a three-necked flask equipped with a stirring device and a condensing reflux device in sequence, and after sufficient stirring, 9 g of a 10% sodium hydroxide aqueous solution was added, and the mixture was heated and stirred at reflux at 50° C. for 10 hours. After the reaction was completed, the solvent and unreacted monomers were removed by rotary evaporation to obtain halogenated nonene carborane;

[0061] (3) Preparation of carborane-modified silicone oil:

[0062] 50 g of hydrogenated silicone oil was added to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, and the temperature was raised to 110° C., and the water was removed by vacuum for 1 hour; 17.6 g of the prepared halogenated nonene carborane and a 0.5 g / L chloroplatinic acid solution were added to a single-necked flask equipped with a magnetic stirrer, and then the temperature was raised to 70° C. and uniformly activated for 15 minutes; the mixed solution of halogenated nonene carborane and chloroplatinic acid after uniform activation for 15 minutes was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, the temperature in the four-necked flask was controlled at 130° C., and the reaction was carried out at a constant temperature for 4 hours; after the reaction was completed, the temperature was lowered to 80° C., vacuum distillation was performed, and the temperature was gradually increased to 130° C. After the low-boiling substances were removed, the material was cooled to room temperature and discharged to obtain carborane-modified silicone oil; the concentration of chloroplatinic acid in the reaction system was 50 ppm.

[0063] Comparative Example 1

[0064] 25 g of hydrogenated silicone oil was added to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, and the temperature was raised to 110°C, and the water was removed by vacuum for 1 hour; 22 g of α-methylstyrene and a 0.5 g / L chloroplatinic acid solution were added to a single-necked flask equipped with a magnetic stirrer, and then the temperature was raised to 70°C and uniformly activated for 15 minutes; the mixed solution of α-methylstyrene and chloroplatinic acid after uniform activation for 15 minutes was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, the temperature in the four-necked flask was controlled at 130°C, and the reaction was carried out at a constant temperature for 4 hours; after the reaction was completed, the temperature was lowered to 80°C, and the vacuum distillation was carried out, and the temperature was gradually raised to 130°C. After the low-boiling substances were removed, the material was cooled to room temperature and discharged to obtain phenyl-modified silicone oil; the concentration of chloroplatinic acid in the reaction system was 30 ppm.

[0065] Comparative Example 2

[0066] 25 g of hydrogenated silicone oil was added to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, and the temperature was raised to 110° C., and the water was removed by vacuum for 1 hour; 40 g of 9-chloro-1-nonene and a 0.5 g / L chloroplatinic acid solution were added to a single-necked flask equipped with a magnetic stirrer, and then the temperature was raised to 70° C. and uniformly activated for 15 minutes; the mixed solution of 9-chloro-1-nonene and chloroplatinic acid after uniform activation for 15 minutes was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, the temperature in the four-necked flask was controlled at 130° C., and the reaction was carried out at a constant temperature for 4 hours; after the reaction was completed, the temperature was lowered to 80° C., vacuum distillation was performed, and the temperature was gradually increased to 130° C. After the low-boiling substances were removed, the material was cooled to room temperature and discharged to obtain modified silicone oil; the concentration of chloroplatinic acid in the reaction system was 30 ppm.

[0067] Comparative Example 3

[0068] 25 g of hydrogenated silicone oil was added to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, and the temperature was raised to 110° C., and the water was removed by vacuum for 1 hour; 41 g of 9-bromo-1-nonene and a 0.5 g / L chloroplatinic acid solution were added to a single-necked flask equipped with a magnetic stirrer, and then the temperature was raised to 70° C. and uniformly activated for 15 minutes; the mixed solution of 9-bromo-1-nonene and chloroplatinic acid after uniform activation for 15 minutes was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, the temperature in the four-necked flask was controlled at 130° C., and the reaction was carried out at a constant temperature for 4 hours; after the reaction was completed, the temperature was lowered to 80° C., vacuum distillation was performed, and the temperature was gradually increased to 130° C. After the low-boiling substances were removed, the mixture was cooled to room temperature and discharged 3 to obtain modified silicone oil; the concentration of chloroplatinic acid in the reaction system was 30 ppm.

[0069] Comparative Example 4

[0070] 25 g of hydrogenated silicone oil was added to a four-necked flask equipped with a stirring paddle, a thermometer, a constant pressure dropping funnel, and a condenser, and the temperature was raised to 110° C., and the water was removed by vacuum for 1 hour; 41 g of 9-iodine-1-nonene and a 0.5 g / L chloroplatinic acid solution were added to a single-necked flask equipped with a magnetic stirrer, and then the temperature was raised to 70° C. and uniformly activated for 15 minutes; the mixed solution of 9-iodine-1-nonene and chloroplatinic acid after uniform activation for 15 minutes was added drop by drop to the hydrogenated silicone oil through a constant pressure dropping funnel, the temperature in the four-necked flask was controlled at 130° C., and the reaction was carried out at a constant temperature for 4 hours; after the reaction was completed, the temperature was lowered to 80° C., vacuum distillation was performed, and the temperature was gradually increased to 130° C. After the low-boiling substances were removed, the material was cooled to room temperature and discharged to obtain the modified silicone oil; the concentration of chloroplatinic acid in the reaction system was 30 ppm.

[0071] Effect example

[0072] Table 1

[0073]

[0074] Table 1 shows the initial temperature of thermal decomposition of silicone oil in each embodiment and comparative example (mass loss 5%). It can be seen from Table 1 that the initial temperature of thermal decomposition of silicone oil after the introduction of 4-hydroxyphenyl carborane is increased by nearly 40% compared with the silicone oil without the introduction of 4-hydroxyphenyl carborane. The reason is that the cage structure of carborane has a high bond energy and a unique three-dimensional configuration. At high temperatures, this stable structure is not easy to deform or decompose, and can effectively resist the destructive effect of heat on molecules, thereby reducing the performance degradation of silicone oil caused by molecular structure destruction, providing a basic thermal stability framework for silicone oil, and because it contains a benzene ring conjugated system, the electrons are delocalized in the benzene ring, making the energy distribution of the molecule more uniform, and the ability to absorb and disperse heat is enhanced. When silicone oil is subjected to high temperature, the conjugated system can transfer and disperse energy in the molecule through the delocalization of electrons, avoiding the concentration of energy on certain specific chemical bonds, thereby reducing the breakage of chemical bonds and the degradation of molecules, and improving the thermal stability of silicone oil.

[0075] Table 2 Radiation resistance test of each embodiment

[0076]

[0077] Table 2 shows the radiation resistance test results of silicone oil in various embodiments (molecular weight is tested by GPC), the radiation source is cobalt-60, γ-ray irradiation (provided by Nanjing Ruisen Radiation Technology Co., Ltd.), the total radiation dose received by the sample under vacuum is 500 kGy, and the radiation dose rate is 100 Gy / min.). As can be seen from the data of each embodiment in Table 2, under the synergistic effect of phenyl and carborane, the molecular weight of silicone oil does not change before and after receiving radiation, while the molecular weight of silicone oil that only introduces benzene rings or long carbon chains decreases to a large extent, indicating that the benzene ring and carborane structure can absorb the energy of high-energy particles or photons generated during the radiation process and convert it into vibration energy or heat energy within the molecule, thereby reducing the direct effect of radiation energy on the silicone oil molecules and reducing the impact of radiation on the performance of silicone oil. After absorbing radiation energy, 4-hydroxyphenyl carborane can dissipate energy in a variety of ways: (1) Vibration and rotation within the molecule can dissipate energy in the form of heat; (2) The interaction between the benzene ring and carborane can also promote the transmission and transfer of energy within the molecule, so that the energy can be more evenly distributed throughout the molecule, avoiding the destruction of chemical bonds due to excessive local energy, thereby improving the radiation resistance of silicone oil.

[0078] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A carborane-modified heat-resistant silicone oil, characterized in that: The side chain of the silicone oil includes a molecular chain containing a benzene ring and carborane.

2. The carborane-modified heat-resistant silicone oil according to claim 1, characterized in that: The structural formula of the carborane-modified heat-resistant silicone oil is: ,in It is a long silicon chain.

3. The carborane-modified heat-resistant silicone oil according to claim 1, characterized in that: The structural formula of the carborane-modified heat-resistant silicone oil is: Among them, x=50-100, y=400-500.

4. A method for preparing the carborane-modified heat-resistant silicone oil according to any one of claims 1 to 3, characterized in that: The steps include: (1) Synthesis of 4-hydroxyphenylcarborane: In a nitrogen atmosphere, 1,2-carborane, anhydrous tetrahydrofuran and n-butyl lithium were mixed at 0-5 degrees Celsius, stirred and reacted for 1 hour, 4-iodoanisole was added at 25°C, the temperature was raised to 90°C and reacted for 24 hours, the residual solvent was removed by vacuum distillation, pyridinium hydrochloride was added, the temperature was 180°C, the reaction was carried out for 5-6 hours, and purification was performed to obtain 4-hydroxyphenylcarborane as a white powder; (2) Synthesis of nonene carborane: N,N-dimethylformamide, 4-hydroxyphenyl carborane and halogenated nonene were mixed under nitrogen atmosphere, and then sodium hydroxide aqueous solution was added after sufficient stirring. The mixture was heated and stirred under reflux at 50° C. for 8-10 hours. After the reaction was completed, the solvent and unreacted monomers were removed by rotary evaporation. (3) Synthesis of carborane-modified hydrogenated silicone oil: The hydrogenated silicone oil is heated to 110°C and vacuumed to remove water for 1 hour; the halogenated nonene carborane and chloroplatinic acid solution are mixed and activated, and then the mixed solution is added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, and the reaction is carried out at a constant temperature of 120-130°C for 3-4 hours; then the temperature is lowered to 80°C, and low-boiling substances are removed by vacuum distillation, and the material is cooled to room temperature to obtain the carborane-modified silicone oil.

5. The method for preparing the carborane-modified heat-resistant silicone oil according to claim 4, characterized in that: The pyridinium hydrochloride in step (1) is one of 2-chloromethyl-3,4-dimethoxypyridine hydrochloride, 4-(chloromethyl)-2-methylpyridine hydrochloride, and 2-chloromethylpyridine hydrochloride; And / or, the mass ratio of 1,2-carborane, anhydrous tetrahydrofuran, n-butyl lithium, 4-iodoanisole and pyridinium hydrochloride in step (1) is (8-9):(6-7):1:(11-12):(34-35).

6. The method for preparing the carborane-modified heat-resistant silicone oil according to claim 4, characterized in that: The halogenated olefin in step (2) is one of 9-chloro-1-nonene, 9-bromo-1-nonene and 9-iodo-1-nonene; and / or, the molar ratio of 4-hydroxyphenylcarborane to halononene in step (2) is 1:1; And / or, the mass concentration of the sodium hydroxide aqueous solution in step (2) is 10%, and the amount of the sodium hydroxide aqueous solution used is 1-1.5 times the molar mass of 4-hydroxyphenylcarborane.

7. The method for preparing the carborane-modified heat-resistant silicone oil according to claim 4, characterized in that: The molar ratio of the hydrogenated silicone oil to the halogenated nonene carborane in step (3) is 1:

1. And / or, the chloroplatinic acid solution in step (3) is an isopropanol solution of chloroplatinic acid hexahydrate; And / or, the concentration of chloroplatinic acid in the reaction system of step (3) is 30-50 ppm; And / or, the hydrogen content of the hydrogen-containing silicone oil in step (3) is 0.8%.

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