Carboryl silane and preparation method thereof

Abstract

The invention discloses carborane alkyl silane and a preparation method thereof. Specifically, the carborane silane has a structure as shown in the specification, and R1 and R2 are respectively and independently selected from the following groups: H, C1-3 alkyl and phenyl. The carborane silane can be dissolved in a conventional low-boiling-point solvent, is suitable for various processing technologies, and can be used for preparing various high-performance composite materials. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of synthesis of organic-inorganic hybrid molecules. Specifically, the present invention relates to a carboranyl silane and a preparation method thereof. Background Art

[0002] Inorganic substances have relatively stable chemical properties and are not easily subject to chemical reactions under conventional conditions. Moreover, they have good heat and oxidation resistance. However, their structures and compositions are relatively simple, resulting in limited functions and application ranges, which are not as diverse as organic molecules. Additionally, due to their high surface activation energy, their interfacial properties with resins are poor. Therefore, when used to prepare composite materials, the mechanical properties of the materials will be significantly reduced.

[0003] Carboranes were first synthesized after the mid-20th century. Subsequent research found that carboranes and their derivatives have the effect of increasing the burning rate for fuel propellants, and a series of process modification studies have been carried out and widely used in the aerospace field. Therefore, carborane derivatives also have excellent properties such as high heat resistance.

[0004] Carboranes are a class of boron cluster compounds with a three-dimensional icosahedral configuration. Due to different arrangements of carbon atoms, there are ortho, meta, and para isomers, among which ortho-carborane has the largest number. Ortho-carborane has been widely used in the fields of optoelectronic materials, catalysis, biomedicine, etc. due to its good thermodynamic stability, chemical stability, unique geometric structure, high boron content, and low biological toxicity.

[0005] In view of this, there is an urgent need in this field to develop an organic-inorganic hybrid system to prepare compounds with high inorganic components having catalytic activity. Summary of the Invention

[0006] One object of the present invention is to provide a carboranyl silane having a catalytic function, which can be added to the system as an inorganic component to effectively improve the thermal oxidation performance of the resin.

[0007] Another object of the present invention is to provide a preparation method of the above-mentioned carboranyl silane.

[0008] In the first aspect of the present invention, there is provided a carboranyl silane having the following structure:

[0009]

[0010] wherein, R1 and R2 are each independently selected from the group consisting of: H, C1-3 alkyl, phenyl.

[0011] In another preferred example, R1 and R2 are each independently selected from the group consisting of: H, methyl, phenyl.

[0012] In a second aspect of the present invention, there is provided a method for preparing the carboranyl silane described in the first aspect of the present invention, comprising the following steps:

[0013] (1) Under the protection of an inert gas, at 25 °C ± 5 °C, 1-bromomethyl-o-carborane is added to a mixture of magnesium, iodine and an inert solvent, and the reaction is carried out at 55 - 70 °C for 1.5 h to 3.5 h to obtain a 1-bromomethyl-o-carborane Grignard reagent;

[0014] Mg + B H 13 C3Br → B 10 H 13 C3MgBr

[0015] (2) At 30 - 40 °C, dichlorosilane is added to the 1-bromomethyl-o-carborane Grignard reagent obtained in step (1), and the reaction is carried out at 55 - 70 °C for 1.5 h to 3.5 h to obtain carboranyl silane; wherein, R1 and R2 are each independently selected from the following group: H, C1-3 alkyl, phenyl;

[0016]

[0017] In another preferred example, the method further comprises a post-treatment step:

[0018] After the reaction is completed, dilute hydrochloric acid solution is added to the reaction solution. After layering, the organic layer is concentrated to obtain carboranyl silane.

[0019] In another preferred example, the post-treatment specifically comprises: after the reaction is completed, dilute hydrochloric acid solution is added to the reaction solution, filtered, the filtrate is separated, dried and concentrated, and the organic layer is recrystallized from ethanol to obtain carboranyl silane.

[0020] In another preferred example, the reaction time of step (1) is 1.5 h to 2 h.

[0021] In another preferred example, in step (1), the molar ratio of 1-bromomethyl-o-carborane to magnesium is 1:(1 - 1.5), preferably 1:1.1.

[0022] In another preferred example, the addition amount of iodine is 0.01 g.

[0023] In another preferred example, iodine is an initiator.

[0024] In another preferred example, in step (1), the inert solvent is selected from the following group: ether solvents; preferably tetrahydrofuran.

[0025] In another preferred example, the magnesium is magnesium powder.

[0026] In another preferred example, the reaction time of step (2) is 2 h - 3 h.

[0027] In another preferred example, the molar ratio of 1-bromomethyl-o-carborane to dichlorosilane is 1:(0.1 - 0.5), preferably 1:(0.4 - 0.5).

[0028] In another preferred example, step (1) includes the following steps: under the protection of an inert gas, magnesium and iodine are added to an inert solvent, and the resulting mixture is stirred at 20°C - 25°C; a mixture of 1-bromomethyl-o-carborane in an inert solvent is added dropwise, and the dropping time is 0.5 - 1 h. During the dropping process, the temperature is controlled at 25°C ± 5°C. After the dropping is completed, the temperature is raised to 60 - 70°C and the reaction is carried out for 1.5 h - 3.5 h to obtain a 1-bromomethyl-o-carborane Grignard reagent.

[0029] In another preferred example, after the reaction is completed, it is cooled to room temperature.

[0030] In another preferred example, step (2) includes the following steps: a mixture of dichlorosilane in an organic solution is added dropwise to the 1-bromomethyl-o-carborane Grignard reagent prepared in step (1), and the dropping time is 0.5 - 1 h. During the dropping process, the temperature is controlled at 30 - 40°C. After the dropping is completed, the temperature is raised to 60 - 70°C and the reaction is carried out for 1.5 - 3.5 h. After the reaction, it is cooled to room temperature.

[0031] In the third aspect of the present invention, there is provided a use of the carboranyl silane described in the first aspect of the present invention for improving the high-temperature resistance performance and stability performance of resinous materials.

[0032] In another preferred example, the carboranyl silane described in the first aspect of the present invention is used for preparing a high-temperature resistant phthalonitrile resin.

[0033] In another preferred example, the carboranyl silane described in the first aspect of the present invention is used for preparing a high-temperature resistant silylacetylene resin.

[0034] In another preferred example, the resinous materials are selected from the following group: phthalonitrile resins (such as phthalonitrile), silylacetylene resins (such as poly(m-diethynylbenzene-diphenylsilane) resin).

[0035] In the fourth aspect of the present invention, there is provided a resin modified with the carboranyl silane described in the first aspect of the present invention.

[0036] In another preferred example, the resins are selected from the following group: phthalonitrile resins, silylacetylene resins.

[0037] In the fifth aspect of the present invention, there is provided a cured product of a resin modified with the carboranyl silane described in the first aspect of the present invention, and the cured product is obtained by curing the resin modified with the carboranyl silane described in the first aspect of the present invention.

[0038] In another preferred example, the curing refers to curing with a temperature gradient.

[0039] In another preferred example, the temperature gradient refers to 150 °C / 2 h + 200 °C / 2 h + 250 °C / 2 h + 300 °C / 2 h + 350 °C / 2 h.

[0040] In another preferred example, the temperature gradient refers to 220 °C / 1 h + 260 °C / 1 h + 300 °C / 2 h + 350 °C / 2 h.

[0041] In another preferred example, the T of the cured product in an air atmosphere d5 is 550 - 700 °C; preferably 550 - 650 °C; more preferably 550 - 600 °C.

[0042] It should be understood that within the scope of the present invention, the above technical features of the present invention and the technical features specifically described below (such as in the examples) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be elaborated one by one here. Description of the Drawings

[0043] Figure 1 It is the infrared spectrum of the carboranyl methylhydrogensilane prepared in Example 1.

[0044] Figure 2 It is the infrared spectrum of the carboranyldimethylsilane prepared in Example 2.

[0045] Figure 3 It is the infrared spectrum of the carboranyl methylphenylsilane prepared in Example 3.

[0046] Figure 4 It is the TGA spectrum of the cured product of the modified poly(m - diethynylbenzene - diphenylsilane) resin in an air atmosphere in Example 4.

[0047] Figure 5 It is the TGA spectrum of the cured product of the modified phthalonitrile resin in an air atmosphere in Example 5. Detailed Embodiments

[0048] Through extensive and in - depth research, the inventors prepared carboranylsilane by the Grignard reagent method. It has good structural designability, and introducing catalytic sites such as Si - H and B - H can achieve covalent bonding with the organic matrix, greatly improving the heat resistance and heat - oxidation resistance of the material, and expanding the application of carborane in the field of organic optoelectronics. Based on this, the inventors completed the present invention.

[0049] Term

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0051] In the present invention, "C1-C3 alkyl" refers to a straight-chain or branched-chain alkyl group containing 1-3 carbon atoms, such as methyl, ethyl, propyl, and isopropyl.

[0052] Carboranyl silane and its preparation method

[0053] A carboranyl silane of the present invention has the following structure:

[0054]

[0055] In particular, the carboranyl silane of the present invention is prepared by the Grignard reagent method. The prepared large and small molecules have a high proportion of inorganic components, good molecular designability, and catalytic sites such as Si-H and B-H. It can achieve the molecular-level combination of organic and inorganic materials, effectively increase the content of inorganic elements in the resin matrix, and greatly improve the heat resistance and thermal oxidation resistance of the resin.

[0056] Typically, the preparation process flow of the compounds of the present invention is as shown in the examples of the present invention. The raw materials and reagents used can be purchased through commercial channels without special instructions.

[0057] The carborane in the carboranyl silane has a unique electron distribution. The empty orbital of the B atom is easily coordinated with the N atom of the cyano group, and the phthalonitrile resin can be effectively catalyzed through the coordination effect; by introducing a silicon-hydrogen bond into the molecule, an addition reaction can occur with the alkynyl group in the silicide resin to participate in curing, realizing the introduction of a highly thermally oxidative carborane structure at the molecular level of the resin; due to the high content of inorganic components in the carboranyl silane (usually >60%), it can be added as an inorganic filler to various resin systems to improve the thermal stability of the resin.

[0058] Specifically, the preparation method of the carboranyl silane of the present invention is as follows:

[0059] Mg + B 10 H 13 C3Br → B 10 H 13 C3MgBr

[0060]

[0061] (1) Under the protection of inert gas, magnesium powder and iodine are added into a four-necked flask, using tetrahydrofuran as a solvent, and stirred at a high speed at 20 °C to 25 °C. Then, a 1-bromomethyl-o-carborane / THF solution is slowly added dropwise through a constant-pressure funnel. The dropping time is 0.5 to 1 h, and the temperature is controlled at 25 °C ± 5 °C during the dropping process. After the dropping is completed, the temperature is raised to 63 °C and reacted for 1.5 h to 3.5 h to obtain a 1-bromomethyl-o-carborane Grignard reagent. After the reaction is completed, it is cooled to room temperature.

[0062] (2) In the 1-bromomethyl-o-carborane Grignard reagent prepared in the first-step reaction, a dichlorosilane / THF solution is slowly added dropwise through a constant-pressure funnel. The dropping time is 0.5 to 1 h, and the temperature is controlled at 30 to 40 °C during the dropping process. After the dropping is completed, the temperature is raised to 63 °C and reacted for 1.5 to 3.5 h. After the reaction, it is cooled to room temperature.

[0063] (3) Dilute hydrochloric acid is added dropwise to the reaction solution and stirred for 1 to 2 h. After filtering out the insoluble solid, deionized water is added until the solution is close to neutral. It is allowed to stand and layer, and the oil layer is separated using a separatory funnel. Anhydrous magnesium sulfate is added and left overnight for drying; the dried oil layer is obtained by suction filtration, and the residual THF is rotary-evaporated to obtain a powdery solid crude product. After recrystallization with ethanol, it is vacuum-dried to obtain the final product.

[0064] Carboranyl silane modified resin

[0065] The carboranyl silane of the present invention can be used as a performance modifier to improve the high-temperature resistance and stability of resin-based materials. Specifically, the carboranyl silane of the present invention can be added as an additive to various resin-based materials that require improved high-temperature resistance and stability performance. Common resin-based materials include, for example, phthalonitrile resins, silatetrayne resins, etc.

[0066] In particular, the phthalonitrile resins include biphenyl-type phthalonitrile resins, benzophenone-type phthalonitrile resins, bisphenol A-type phthalonitrile resins, bisphenol AF-type phthalonitrile resins, bisphenol F-type phthalonitrile resins, bisphenol S-type phthalonitrile resins, and the structural formulas are as follows:

[0067]

[0068] The silatetrayne resins include, but are not limited to: poly(m-diethynylbenzene-diphenylsilane) resin, methyldiphenylacetylenylsilane.

[0069] The present invention also provides a method for modifying the performance of carboranyl silane modified resin, such as the solvent method, which includes the following steps:

[0070] Under the protection of inert gas, the resin-based material to be improved and the carboranyl silane disclosed in the present invention are dissolved in an inert solvent, stirred, and reacted under heating or non-heating conditions to obtain a modified resin prepolymer.

[0071] In one embodiment of the present invention, the inert gas is a stable gas commonly used in the art and does not react with other substances. The inert gas includes, but is not limited to: nitrogen, argon, helium, etc.

[0072] Among them, the inert solvent includes, but is not limited to: aromatic solvents, amide solvents, or combinations thereof; preferably N,N-dimethylformamide, N-methylpyrrolidone, N,N-dimethylacetamide, 1,2-diphenyl ether, or combinations thereof; more preferably N-methylpyrrolidone, diphenyl ether.

[0073] The obtained modified resin prepolymer can be further cured to obtain a resin cured product with improved properties.

[0074] Compared with the prior art, the main advantages of the present invention include:

[0075] (1) The present invention prepares carboranyl silane by the Grignard reagent method, and the prepared small molecule has a high inorganic proportion and good molecular designability.

[0076] (2) The carboranyl silane prepared by the present invention has catalytic sites such as Si-H and B-H, can realize the molecular-level combination of organic and inorganic materials, effectively improve the content of inorganic elements in the resin matrix, and greatly improve the heat resistance and thermal oxidation resistance of the resin.

[0077] (3) The carboranyl silane prepared by the present invention is soluble in conventional low-boiling solvents, is suitable for improving various resins, and is used for preparing various high-performance composite materials.

[0078] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are calculated by weight.

[0079] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the method of the present invention. The preferred implementation methods and materials described herein are only for demonstration purposes.

[0080] Example 1

[0081] Preparation steps of carboranyl methylhydrogensilane:

[0082] Under anhydrous and anaerobic conditions, add 0.2 mol of magnesium powder, 0.01 g of iodine, and 25 g of THF to a four-necked flask and stir at high speed. Dissolve 0.18 mol of 1-bromomethylcarborane in 20 g of THF, and slowly add it dropwise through a constant-pressure funnel while controlling the temperature at 25°C ± 5°C. After the addition is complete, raise the temperature to 63°C, reflux for 1.5 h, and then cool to room temperature.

[0083] Dissolve 0.085 mol of methylhydrodichlorosilane in 15 g of THF, and slowly add it dropwise into the 1-bromomethylo-carborane Grignard reagent through a constant-pressure funnel while controlling the temperature at 30 - 40°C. After the addition is complete, raise the temperature to 63°C and reflux for 2 h.

[0084] Add dilute hydrochloric acid dropwise to the reaction solution and stir for 1 h until the solution becomes acidic. Filter out the insoluble solid, add deionized water until the solution is nearly neutral, let it stand for liquid separation, use a separatory funnel to separate to obtain the oil layer, add anhydrous magnesium sulfate and let it stand overnight for drying. Filter to obtain the dried oil layer, rotary evaporate to remove the residual THF to obtain a powdery solid, recrystallize with ethanol, and then dry under vacuum to obtain the final product.

[0085] Example 2

[0086] Preparation steps of carboranyldimethylsilane:

[0087] Under anhydrous and anaerobic conditions, add 0.2 mol of magnesium powder, 0.01 g of iodine, and 30 g of THF to a four-necked flask and stir at high speed. Dissolve 0.18 mol of 1-bromomethylcarborane in 20 g of THF, and slowly add it dropwise through a constant-pressure funnel while controlling the temperature at 25°C ± 5°C. After the addition is complete, raise the temperature to 63°C, reflux for 1.5 h, and then cool to room temperature.

[0088] Dissolve 0.085 mol of dimethyldichlorosilane in 20 g of THF, and slowly add it dropwise into the 1-bromomethylo-carborane Grignard reagent through a constant-pressure funnel while controlling the temperature at 30 - 40°C. After the addition is complete, raise the temperature to 63°C, reflux for 2.5 h, and then cool to room temperature.

[0089] Add dilute hydrochloric acid dropwise to the reaction solution and stir for 2 h until the solution becomes acidic. Filter out the insoluble solid, add deionized water until the solution is nearly neutral, let it stand for liquid separation, use a separatory funnel to separate to obtain the oil layer, add anhydrous magnesium sulfate and let it stand overnight for drying. Filter to obtain the dried oil layer, rotary evaporate to remove the residual THF to obtain a powdery solid, recrystallize with ethanol, and then dry under vacuum to obtain the final product.

[0090] Example 3

[0091] Preparation steps of carboranyldiphenylsilane:

[0092] Under anhydrous and anaerobic conditions, 0.2 mol of magnesium powder, 0.01 g of iodine, and 30 g of THF were added to a four-necked flask and stirred at high speed. 0.18 mol of 1-bromomethylcarborane was dissolved in 20 g of THF and slowly added dropwise through a constant pressure funnel while controlling the temperature at 25°C ± 5°C. After the addition was completed, the temperature was raised to 63°C, and after refluxing for 2 h, it was cooled to room temperature.

[0093] 0.08 mol of diphenyldichlorosilane was dissolved in 20 g of THF and slowly added dropwise into the 1-bromomethyl-o-carborane Grignard reagent through a constant pressure funnel while controlling the temperature at 30 - 40°C. After the addition was completed, the temperature was raised to 63°C, and after refluxing for 3 h, it was cooled to room temperature.

[0094] Dilute hydrochloric acid was added dropwise to the reaction solution and stirred for 2 h until the solution became acidic. After filtering out the insoluble solids, deionized water was added until the solution was nearly neutral, and then it was allowed to stand for layering. The oil layer was separated using a separatory funnel, and anhydrous magnesium sulfate was added and left overnight for drying. The dried oil layer was obtained by suction filtration, and the residual THF was removed by rotary evaporation to obtain a powdery solid. After recrystallization from ethanol and vacuum drying, the final product was obtained.

[0095] Example 4

[0096] By the solution method, 10 g of poly(m - diethynylbenzene - diphenylsilane) resin and 1 g of the carboranyl - methyl - hydrosilane prepared in Example 1 were dissolved in acetone, stirred for 30 min to mix evenly, and the solvent was evaporated by rotary evaporation to obtain a modified silane - acetylene resin. The resin was placed in a muffle furnace and cured by step - wise heating according to the conditions of 150°C / 2 h + 200°C / 2 h + 250°C / 2 h + 300°C / 2 h + 350°C / 2 h.

[0097] By introducing carboranyl - methyl - hydrosilane, the initial curing temperature of the silane - acetylene resin was reduced from 230°C to 195°C. The obtained cured product was subjected to TGA testing in an air atmosphere at a heating rate of 10°C / min. The T d5 increased from 532°C to 554°C, and the char yield increased from 23% to 50%.

[0098] Example 5

[0099] 10 g of biphenyl - type phthalonitrile monomer, 0.5 g of the carboranyl - dimethyl - silane prepared in Example 2, and 8 g of N - methylpyrrolidone were added to a dry four - necked flask. Under nitrogen protection, the temperature was raised to 200°C, and the reaction was carried out for 2 h under high - speed stirring. After the reaction was completed, it was cooled to room temperature. The obtained product solution was poured into 500 ml of water, and a large amount of black precipitate appeared. It was filtered by suction, and the filter residue was washed repeatedly with deionized water and ethanol solution, and then vacuum dried to obtain a black solid, namely the modified phthalonitrile resin prepolymer.

[0100] After the modified resin was ground, a small amount of powder was taken and placed in a ceramic crucible, and stepwise temperature rise curing was carried out in a muffle furnace under the conditions of 220 °C / 1 h + 260 °C / 1 h + 300 °C / 2 h + 350 °C / 2 h. The obtained cured product was subjected to TGA test in an air atmosphere at a heating rate of 10 °C / min until d5 it reached 560 °C, and the char residue rate was 32%.

[0101] All documents mentioned in the present invention are cited herein as references, as if each document was individually cited as a reference. In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A carboranyl silane, characterized in that, The described carboranyl silane has the structure shown below: Wherein, R1 and R2 are each independently selected from the group consisting of: H, C1-3 alkyl, phenyl.

2. The preparation method of the carboranyl silane according to claim 1, characterized in that, Comprising the following steps: (1) Under the protection of an inert gas, at 25°C ± 5°C, add 1-bromomethyl ortho-carborane to a mixture of magnesium, iodine and an inert solvent, and react at 55-70°C for 1.5 h to 3.5 h to obtain a 1-bromomethyl ortho-carborane Grignard reagent; Mg + B 10 H 13 C3Br → B 10 H 13 C3MgBr (2) At 30-40 °C, dichlorosilane is added to the 1-bromomethyl-o-carboranyl Grignard reagent obtained in step (1). React at 55-70 °C for 1.5 h to 3.5 h to obtain carboranyl silane; wherein, R1 and R2 are each independently selected from the following group: H, C1-3 alkyl, phenyl.

3. The preparation method according to claim 2, characterized in that, The described method further includes a post-treatment step: After the reaction is completed, add a dilute hydrochloric acid solution to the reaction solution. After layering, concentrate the organic layer to obtain carboranyl silane.

4. The preparation method according to claim 2, characterized in that, The reaction time of step (1) is 1.5 h to 2 h.

5. The preparation method according to claim 2, characterized in that, In step (1), the molar ratio of 1-bromomethyl ortho-carborane to magnesium is 1:(1 to 1.5), preferably 1:1.

1.

6. The preparation method according to claim 2, characterized in that, The specific post-treatment includes: after the reaction is completed, add a dilute hydrochloric acid solution to the reaction solution, filter, separate the filtrate, dry and concentrate the organic layer to obtain a crude carboranyl silane product, and recrystallize with ethanol to obtain carboranyl silane.

7. The preparation method according to claim 2, characterized in that, In step (1), the described inert solvent is selected from the group consisting of: ether solvents; preferably tetrahydrofuran.

8. The preparation method according to claim 2, characterized in that, Step (1) includes the following steps: under the protection of an inert gas, add magnesium and iodine to an inert solvent, and stir the resulting mixture at 20°C to 25°C; add dropwise a mixture of 1-bromomethyl ortho-carborane in an inert solvent, with the dropping time being 0.5 to 1 h, controlling the temperature at 25°C ± 5°C during the dropping process, and after the dropping is completed, raise the temperature to 60-70°C and react for 1.5 h to 3.5 h to obtain a 1-bromomethyl ortho-carborane Grignard reagent.

9. The preparation method according to claim 2, wherein, The molar ratio of 1-bromomethyl ortho-carborane to dichlorosilane is 1:(0.1 to 0.5), preferably 1:(0.4 to 0.5).

10. Use of the carboranyl silane according to claim 1, characterized in that, It is used to improve the high-temperature resistance and stability of resinous materials.

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