Carbonborane modified heat-resistant silicone oil and preparation method thereof

Abstract

The application belongs to the field of organic silicon materials, and particularly relates to a 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 a carborane structure into a side chain of a silicone oil. The heat resistance and radiation resistance of the hydrogen-containing silicone oil are significantly improved by using the synergistic effect of the benzene ring and the carborane cage structure. The modified silicone oil can still maintain good physical and chemical properties in a high-temperature and radiation environment, and the application range of the silicone oil in the high-temperature and radiation fields is expanded. The modified silicone oil rubber material containing the carborane structure can be further processed and used in a thermal protection system of an aircraft to prevent the brittle and cracking of the material caused by the severe friction between the surface of the aircraft and the air during high-speed flight, thereby effectively protecting the structural integrity of the aircraft.

Description

Technical Field

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

[0002] Silicone oil is an organopolysiloxane 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), making the silicone oil molecular chain less susceptible to decomposition at high temperatures. It can maintain stable performance over a wide temperature range. While standard heat-resistant silicone oils can operate normally within a temperature range of -50°C to 200°C, some high-performance heat-resistant silicone oils can even withstand temperatures as high as 300°C. Even at such high temperatures, their viscosity changes minimally, with no noticeable decomposition or carbonization.

[0003] However, in some extreme operating conditions, such as when aircraft engines are operating, internal temperatures can reach extremely high, with temperatures in local areas, such as near the combustion chamber, exceeding 400°C. Silicone oil, as a lubricant, needs to maintain excellent lubrication properties in such high-temperature environments to reduce friction and wear between engine components and ensure efficient and reliable engine operation. Conventional silicone oil cannot meet the requirements of these extreme operating conditions, especially during high-speed flight, where friction between protective materials on the aircraft's surface and the air generates high temperatures. Therefore, improvements to the physical and chemical properties of silicone oil are necessary to enhance its heat resistance, radiation resistance, and aging resistance in these specific application scenarios.

[0004] The current method for improving heat resistance primarily involves adding 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 with a metallocene-based silazane. This composite improves the silicone oil's heat-oxidative resistance while reducing thermal degradation and weight loss of the molecular chain, resulting in improved overall heat resistance. However, in practical applications, this physical blending modification can lead to problems such as phase separation, insufficient interfacial strength, poor processing performance, and decreased thermal stability. Summary of the Invention

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

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

[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 application requirements in extreme fields that most silicone oils and silicone rubbers cannot meet, such as lubricating oils for aircraft engines and protective materials on the surface of aircraft bodies.

[0010] In certain embodiments, the carborane-modified heat-resistant silicone oil first prepares 4-hydroxyphenylcarborane through the lithiation reaction and reduction reaction of o-carborane, then reacts it with a halogenated olefin through a nucleophilic substitution reaction to generate a long-chain olefin carborane, and finally grafts it onto the side chain of the hydrogenated silicone oil through a hydrosilylation reaction to form a block copolymer. The introduction of the 4-hydroxyphenylcarborane 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, then 4-iodoanisole was added at 25°C, the temperature was raised to 90°C and the reaction was continued for 24 hours. The residual solvent was removed by vacuum distillation, pyridinium hydrochloride was added, and the reaction was continued at 180°C for 5-6 hours. After washing with dilute hydrochloric acid solution and purification by column chromatography, 4-hydroxyphenylcarborane was obtained as a white powder, and 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, stirred thoroughly, and then sodium hydroxide aqueous solution was added. The mixture was heated and stirred under reflux at 50°C for 8-10 hours. After the reaction, 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 it to 110°C, and remove water under vacuum 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 it to 70°C and activate it 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 it to 80°C, distill it under reduced pressure, and gradually increase the temperature to 130°C. After the low-boiling substances are removed, cool it to room temperature and discharge it 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 prepares carborane-modified heat-resistant silicone oil by introducing a molecular chain containing a benzene ring and a carborane structure into the side chain of a 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 absorb the energy of high-energy particles or photons generated during the radiation process and convert it into vibrational 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 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 significantly improved, but it also has excellent radiation resistance and aging resistance, allowing the material to be used in most extreme environments. The various properties of the material can meet the needs of fields such as aircraft engines and aircraft shells. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0030] Figure 2 1 is the thermogravimetric analysis spectrum of the hydrogen-containing silicone oil and the carborane-modified silicone oil (modified silicone oil) in Example 1. DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0032] Example 1

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

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

[0035] (2) Preparation of Halonenylcarborane

[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 sequentially to a three-necked flask equipped with a stirring device and a condensing reflux device. After thorough stirring, 3 g of a 10% aqueous sodium hydroxide solution was added, and the mixture was heated and stirred at reflux at 50°C for 10 hours. After the reaction, the solvent and unreacted monomers were removed by distillation under reduced pressure to obtain a halogenated nonene carborane.

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

[0038] 25 g of hydrogenated silicone oil (Foshan Huagu Organic Silicone Co., Ltd., model 0.8%, molecular weight 18,000-20,000) 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 vacuum-dried for 1 hour. 8.8 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 after uniform activation for 15 minutes was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, and 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 distilled under reduced pressure, and the temperature was gradually increased to 130° C. After the low-boiling point was 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 30 ppm.

[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. -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, 890 cm -1 , 1060cm -1 and 1210cm -1 The left and right are the characteristic peaks of Si-R, 890 cm -1 These are characteristic peaks of para-disubstituted benzene rings. The appearance of the above characteristic peaks indicates the successful introduction of carborane groups and the successful synthesis of carborane-modified heat-resistant silicone oil.

[0040] like Figure 2 The thermogravimetric analysis spectrum shows that the initial decomposition temperature of the hydrogenated silicone oil before modification (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 replaced by 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 sequentially to a three-necked flask equipped with a magnetic stirring device. After thorough stirring for 1 h, 12 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 dilute hydrochloric acid solution and purification by column chromatography, 4-hydroxyphenylcarborane was obtained as a white powder. 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-hydroxyphenylcarborane, and 4.4 g of 9-chloro-1-nonene were added sequentially to a three-necked flask equipped with a stirring device and a condensing reflux device. After thorough stirring, 6 g of a 10% aqueous sodium hydroxide solution was added, and the mixture was heated and stirred at reflux at 50° C. for 10 hours. After the reaction, the solvent and unreacted monomers were removed by rotary evaporation to obtain a 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, 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 carried out, 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 sequentially to a three-necked flask equipped with a magnetic stirring device. After thorough stirring for 1 hour, 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 hours. 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 hours. After washing with a dilute hydrochloric acid solution and purification by column chromatography, 4-hydroxyphenylcarborane was obtained as a white powder, and the reaction was completed.

[0059] (2) Preparation of Halonenylcarborane

[0060] Under a nitrogen atmosphere, 15 g of N,N-dimethylformamide, 7.2 g of the prepared 4-hydroxyphenylcarborane, and 6 g of 9-chloro-1-nonene were added sequentially to a three-necked flask equipped with a stirring device and a condensing reflux device. After thorough stirring, 9 g of a 10% aqueous sodium hydroxide solution was added, and the mixture was heated and stirred at reflux at 50° C. for 10 hours. After the reaction, the solvent and unreacted monomers were removed by rotary evaporation to obtain a 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, 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 carried out, 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, the temperature was raised to 110° C., and vacuum was applied to remove water 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., vacuum distillation was carried out, 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 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 the temperature was then raised to 70° C. and uniformly activated for 15 minutes. The mixed solution of 9-chloro-1-nonene and chloroplatinic acid, which had been uniformly activated for 15 minutes, was added dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel, and 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 vacuum distillation was performed, and the temperature was gradually increased to 130° C. After the low-boiling substances were completely removed, the product 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.

[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, the temperature was raised to 110° C., and vacuum was applied to remove water 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 carried out, and the temperature was gradually increased to 130° C. After the low-boiling substances were completely 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, the temperature was raised to 110° C., and vacuum was applied to remove water 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 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 carried out, and the temperature was gradually increased to 130° C. After the low-boiling substances were completely 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 Examples

[0072] Table 1

[0073]

[0074] Table 1 shows the initial thermal decomposition temperature (mass loss 5%) of the silicone oils of various examples and comparative examples. As can be seen from Table 1, the initial thermal decomposition temperature of the silicone oil after the introduction of 4-hydroxyphenylcarborane was increased by nearly 40% compared to the silicone oil without the introduction of 4-hydroxyphenylcarborane. This is because the cage structure of carborane has a high bond energy and a unique three-dimensional configuration. At high temperatures, this stable structure is not easily deformed or decomposed, and can effectively resist the destructive effects of heat on the molecules, thereby reducing the performance degradation of the silicone oil caused by molecular structure destruction and providing a basic thermal stability framework for the silicone oil. In addition, because it contains a conjugated benzene ring system, electrons are delocalized within the benzene ring, making the energy distribution of the molecule more uniform and enhancing the ability to absorb and disperse heat. When the silicone oil is subjected to high temperatures, the conjugated system can transfer and disperse energy within the molecule through the delocalization of electrons, avoiding energy concentration on certain specific chemical bonds, thereby reducing chemical bond breakage and molecular degradation, and improving the thermal stability of the silicone oil.

[0075] Table 2 Radiation resistance test of each embodiment

[0076]

[0077] Table 2 shows the radiation resistance test results of the silicone oils of various examples (molecular weight was measured using GPC). The radiation source was cobalt-60, γ-ray irradiation (provided by Nanjing Ruisen Radiation Technology Co., Ltd.), and the total radiation dose received by the samples under vacuum was 500 kGy at an irradiation rate of 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. This shows 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 silicone oil molecules and reducing the impact of radiation on silicone oil properties. 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] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and 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; the structural formula of the carborane-modified heat-resistant silicone oil is: ,in It is a long silicon chain.

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

3. A method for preparing the carborane-modified heat-resistant silicone oil according to any one of claims 1 to 2, 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 and stirred at 0-5 degrees Celsius for 1 hour. 4-iodoanisole was then added at 25°C and the temperature was raised to 90°C for 24 hours. The residual solvent was removed by distillation under reduced pressure, and pyridinium hydrochloride was added. The mixture was reacted at 180°C for 5-6 hours and purified to obtain 4-hydroxyphenylcarborane as a white powder. (2) Synthesis of halononene carborane: N,N-dimethylformamide, 4-hydroxyphenyl carborane and halononene were mixed under nitrogen atmosphere, stirred thoroughly, and then sodium hydroxide aqueous solution was added. 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: Heat the hydrogenated silicone oil to 110°C and remove water under vacuum for 1 hour; mix the halogenated nonene carborane and chloroplatinic acid solution and activate them, then add the mixed solution dropwise to the hydrogenated silicone oil through a constant pressure dropping funnel and keep the temperature at 120-130°C for 3-4 hours; then cool to 80°C and remove low-boiling substances by vacuum distillation. Cool to room temperature and discharge to obtain carborane-modified silicone oil.

4. The method for preparing the carborane-modified heat-resistant silicone oil according to claim 3, wherein: 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).

5. The method for preparing the carborane-modified heat-resistant silicone oil according to claim 3, wherein: The halogenated nonene in step (2) is one of 9-chloro-1-nonene, 9-bromo-1-nonene, and 9-iodo-1-nonene; And / or, step (2) wherein the molar ratio of 4-hydroxyphenylcarborane and halogenated nonene 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.

6. The method for preparing the carborane-modified heat-resistant silicone oil according to claim 3, wherein: 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%.

Images