Amino-functionalized carborane as well as preparation method and application thereof

Abstract

The invention provides amino-functionalized carborane as well as a preparation method and application thereof, and belongs to the field of advanced functional materials. The preparation method of the amino-functionalized carborane comprises the following steps: (1) in a solvent, reacting a decaborane-acetonitrile complex and a compound containing alkynyl and halogen as raw materials; (2) after the reaction is finished, carrying out post-treatment by adopting a solvent extraction method to obtain chlorinated carborane; (3) reacting the chlorinated carborane obtained in the step (2), an amine compound and alkali as raw materials in a solvent; and (4) removing the Boc protecting group from the product obtained after the reaction in the step (3) to obtain the amino-functionalized carborane. The amino-functionalized carborane is used for modifying the resin, so that the heat resistance, the mechanical property and the glass-transition temperature of the resin can be remarkably improved. The modified resin can be used in various parts in aviation equipment and nuclear reactor protection layers, and has a wide application prospect in the fields of aerospace and nuclear reaction.

Description

Technical Field

[0001] The invention belongs to the field of advanced functional materials, and specifically relates to an amine-functionalized carborane and a preparation method and application thereof. Background Art

[0002] With the rise of aerospace and nuclear industries, researchers began to develop materials with multiple functions to meet different application scenarios (such as high temperature, high load, neutron irradiation, etc.). This puts forward requirements for materials with high glass transition temperature, thermal oxidation resistance, high carbon yield, excellent mechanical properties and neutron absorption performance.

[0003] Carborane is an icosahedral cage-shaped space compound with properties similar to aromatic compounds and special thermal stability. Carborane contains a high content of H (9.59%) and B (73.97%) elements. Therefore, carborane is also widely used in a variety of polymers to significantly improve the heat resistance of polymers. For example, the papers "Study on thermal degradation mechanism of heat-resistant epoxy resin modified with carboranes" (Cui M, Zhang L, Lou P, et al. Polymer Degradation and Stability, 2020, 176: 109143. DOI: 10.1016 / j.polymdegradstab.2020.109143.) and "Synthesis and Performance Study of Carborane Phenolic Resin" (Qi Shicheng, Wang Yaoshuang, Wang Hongrui, et al. Journal of Aeronautical Materials, 2014, 34 (1): 6. DOI: CNKI: SUN: HKCB. 0.2014-01-008.) disclosed that the heat resistance of carborane-based polymers has been greatly improved. However, carborane has limited effect in improving the heat resistance of polymers, and functionalized carborane is expected to solve the problems of carborane.

[0004] At present, there are two main methods for preparing functionalized carboranes: (1) using decaborane acetonitrile complex as raw material and adopting alkyne hydrogen addition method for preparation, that is, reacting a compound with target functional group and triple bond with decaborane acetonitrile complex. However, some functionalized carboranes cannot be prepared by this method, such as polar group-substituted alkynes containing amine, carboxyl and epoxy groups are not suitable for the above method (Lu Juyou et al. Progress in the synthesis of carborane derivatives. Synthetic Chemistry, 2015, 23(9):10.); (2) using carborane (ortho, meta or para) as raw material, taking advantage of the weak acidity of carborane and using strong base (alkyl lithium, etc.) for catalytic preparation. However, due to the high activity of alkyl lithium and great safety risks, it is not suitable for large-scale preparation (Nekvinda J, Bohumír Grüner, Gabel D, et al. Host–Guest Chemistry of Carboranes: Synthesis of Carboxylate Derivatives and Their Binding to Cyclodextrins[J].Chemistry(Weinheim an der Bergstrasse,Germany),2018(49).DOI:10.1002 / chem.201802134.). Taking aminated carborane as an example, the preparation of aminated carborane at home and abroad is mainly divided into the following steps: the first step is the synthesis of phenyl carborane, the second step is the introduction of nitro group by nitration reaction, and the third step is the reduction of nitro group to amine group: (Li-Li SU, Ya-Lin S, Zhen-Jiang Z, et al. Study on the Thermal Degradation and Stability of Polyurethane Elastomer[J]. Journal of Luoyang Normal University,2011.)

[0005]

[0006] This method uses reagents such as n-butyl lithium and concentrated acid, which has great safety risks and does not meet the prerequisites for mass production. In addition, the synthesis of functionalized carborane is currently mainly purified by column chromatography, which is inefficient (Toppino A, Genady AR, El-Zaria ME, et al. High Yielding Preparation of Dicarba-closo-dodecaboranes Using a Silver(I)Mediated Dehydrogenative Alkyne-Insertion Reaction[J]. Inorganic Chemistry, 2013, 52(15)).

[0007] The synthesis of aminated carborane by the above method and the introduction of carborane into the resin system have problems such as low efficiency and high cost, which means that the aminated carborane modified resin can only be prepared in small batches at present, and the research on its performance is mainly focused on heat resistance, and the research on mechanical properties, glass transition temperature, etc. is missing. In addition, there is still the problem of preparation difficulties in modifying resins using existing aminated carboranes. For example, Cui et al. incorporated amino functionalized carborane into the resin cross-linking network through a curing reaction. This modification significantly improves the thermal stability of the material. Under a nitrogen atmosphere, the carbon yield reaches 61% when the load is 20wt%. B2O3 is generated during the degradation process, which enhances the protective properties of the material. However, the complex synthesis and purification process hinders scalability (Cui, M.; Zhang, L.; Lou, P.; Zhang, X.; Han, X.; Zhang, Z.; Zhu, S. Study on thermal degradation mechanism of heat-resistant epoxy resin modified with carboranes. Polymer Degradation and Stability 2020, 176, 30971-30979.).

[0008] Therefore, it is of great significance to study an amine-functionalized carborane with a simple preparation method, suitable for large-scale production, and excellent polymer modification. Summary of the invention

[0009] The purpose of the present invention is to provide an amine-functionalized carborane and a preparation method and use thereof.

[0010] The present invention provides a method for preparing an amine-functionalized carborane, which comprises the following steps:

[0011] (1) In a solvent, a decaborane-acetonitrile complex and a compound containing an alkynyl group and a halogen are reacted as raw materials;

[0012] (2) after the reaction is completed, a solvent extraction method is used for post-treatment to obtain chlorinated carborane;

[0013] (3) reacting the chlorinated carborane obtained in step (2), an amine compound and a base as raw materials in a solvent;

[0014] (4) removing the Boc protecting group from the product obtained after the reaction in step (3) to obtain an amine-functionalized carborane.

[0015] Further,

[0016] In step (1), the molar ratio of the decaborane-acetonitrile complex to the compound containing an alkynyl group and a halogen is 1:(1-3);

[0017] And / or, in step (1), the solvent is toluene;

[0018] And / or, in step (1), the reaction temperature is 80-120° C., and the reaction time is 8-20 h;

[0019] and / or, in step (3), the molar ratio of the chlorinated carborane to the amine compound is 1:(2-3);

[0020] And / or, in step (3), the mass ratio of the chlorinated carborane to the base is 1:(0.5-1.5);

[0021] And / or, in step (3), the solvent is N,N-dimethylformamide or tetrahydrofuran;

[0022] And / or, in step (3), the reaction temperature is 80-100° C., and the reaction time is 8-10 h;

[0023] And / or, in step (3), filtering after the reaction, removing the solvent, adding dichloromethane to dissolve and then removing the Boc protecting group;

[0024] And / or, in step (4), the method for removing the Boc protecting group comprises the following steps: adding trifluoroacetic acid to the product of step 3) for reaction, then adding a mixture of alkali and water to continue the reaction, cooling until the product precipitates, and drying the product;

[0025] Preferably,

[0026] In step (1), the compound containing an alkynyl group and a halogen is 1,4-butyne dichloro, di(4-bromophenyl)alkyne, 4-bromophenylacetylene or 3-chloropropyne;

[0027] And / or, in step (3), the amine compound is N-(tert-butyloxycarbonyl)-1,4-phenylenediamine or N-tert-butyloxycarbonyl-1,3-propylenediamine;

[0028] And / or, in step (4), the temperature of adding trifluoroacetic acid to react is 40 to 60° C., and the reaction time is 1 to 5 hours;

[0029] And / or, in step (4), the mixture of alkali and water is a mixture of sodium hydroxide and water or aqueous ammonia;

[0030] And / or, in step (4), the mixture of alkali and water is added and the reaction time is continued for 1 to 5 hours.

[0031] Furthermore, in step (1), the decaborane-acetonitrile complex is prepared using decaborane and anhydrous acetonitrile as raw materials; the mass volume ratio of decaborane to anhydrous acetonitrile is (5-500) g: (10-2000) ml;

[0032] Preferably, in step (1), the preparation method of the decaborane-acetonitrile complex comprises the following steps: dissolving decaborane in anhydrous acetonitrile, filtering after the reaction, to obtain;

[0033] More preferably, the reaction temperature is 50-200° C., and the reaction time is 1-20 h.

[0034] Furthermore, in step (2), the extraction method comprises the following steps:

[0035] 1) After the reaction is completed, add activated molecular sieves and stir, then add saturated salt solution to the solution for extraction;

[0036] 2) Collect the upper organic phase after extraction and remove the solvent;

[0037] Preferably,

[0038] In step 1), the molecular sieve is a 4A molecule;

[0039] And / or, in step 1), the saturated salt solution is a saturated sodium chloride solution;

[0040] And / or, in step 1), the extraction is performed 1 to 10 times.

[0041] The present invention also provides an amine-functionalized carborane, which is prepared by the above-mentioned preparation method.

[0042] The present invention also provides the use of the above-mentioned amine-functionalized carborane as a curing agent in the preparation of a resin-based composite material.

[0043] The present invention also provides a resin-based composite material, which is prepared from raw materials in the following weight ratio:

[0044] 1-10 parts of resin matrix, 1-5 parts of the aforementioned amine-functionalized carborane, 0.01-0.1 parts of defoaming agent, and 0.01-0.1 parts of leveling agent;

[0045] Preferably,

[0046] It is prepared from the following raw materials in the following weight ratio:

[0047] 5 parts of resin matrix, 2.5-3.5 parts of the aforementioned amine-functionalized carborane, 0.05 parts of defoaming agent, and 0.05 parts of leveling agent;

[0048] Alternatively, it is prepared from the following raw materials in the following weight ratio:

[0049] 3 parts of resin matrix, 1.82-2.55 parts of the aforementioned amine-functionalized carborane, 0.05 parts of defoaming agent, and 0.05 parts of leveling agent.

[0050] Further,

[0051] The resin matrix is ​​epoxy resin, and the epoxy resin is preferably mAFG-90;

[0052] And / or, the defoaming agent is fluorine-modified silicone;

[0053] And / or, the leveling agent is polyether-modified polysiloxane.

[0054] The present invention also provides a method for preparing the aforementioned resin-based composite material, which comprises the following steps:

[0055] (A) dissolving the aforementioned amine-functionalized carborane in a solvent, adding a resin matrix, a defoamer and a leveling agent, and stirring to obtain a uniform mixture;

[0056] (B) coating the mixture;

[0057] (C) The coating is cured to obtain the product;

[0058] Preferably,

[0059] In step (A), the solvent is methanol, ethanol, acetone, n-propanol, isopropanol, ethyl acetate or 2-butanone;

[0060] And / or, in step (A), the stirring temperature is 50 to 100° C., and the stirring time is 0.5 to 1 hour;

[0061] And / or, in step (B), the coating machine blade height is 20-200 μm, the coating thickness is 10-150 μm, and the coating speed is 1-20 s / cm;

[0062] And / or, in step (C), the curing conditions are 80-100° C. for 0.5-5 hours, then 120-160° C. for 1-5 hours, and finally 170-180° C. for 1-5 hours.

[0063] The present invention also provides the use of the aforementioned resin-based composite material in preparing various components in aviation equipment and devices used in nuclear reactor protective layers.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] The present invention provides a new method for synthesizing functionalized carborane. First, dichlorocarborane is synthesized by an alkyne hydrogen addition method, and then purified by a simple water extraction method to obtain chlorinated carborane. The yield is high, the purification is simple, and it can be prepared in large quantities. With the chlorinated carborane as an intermediate product, a target functional group can be connected to the carborane structure by a simple halogen substitution reaction to obtain a new functionalized carborane with different target functional groups. The method for preparing functionalized carborane of the present invention is simple and has great universality. The present invention adopts a new method for synthesizing functionalized carborane to synthesize a new amino-functionalized carborane, and the epoxy resin is modified by the new amino-functionalized carborane, which can significantly improve the heat resistance, mechanical properties and glass transition temperature of the epoxy resin. The modified epoxy resin can be used in various components in aviation equipment and in the protective layer of nuclear reactors, and has broad application prospects in the fields of aerospace and nuclear reactions.

[0066] Obviously, according to the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, other various forms of modification, replacement or change may be made.

[0067] The above contents of the present invention are further described in detail below through specific implementation methods in the form of embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies realized based on the above contents of the present invention belong to the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 The mechanical properties test results of Et-CBNH2 modified epoxy resin.

[0069] Figure 2 The results of heat resistance test of Et-CBNH2 modified epoxy resin.

[0070] Figure 3This is the Tg test result of Et-CBNH2 modified epoxy resin.

[0071] Figure 4 The simulation results of neutron shielding performance of Et-CBNH2 modified epoxy resin.

[0072] Figure 5 This is the Tg test result of Ph-CBNH2 modified epoxy resin.

[0073] Figure 6 These are the test results of heat resistance of Ph-CBNH2 modified epoxy resin.

[0074] Figure 7 It is the comparison of weight loss temperature of Ph-CBNH2 modified epoxy resin and PDA-1.0; Temperature is the difference of weight loss temperature between Ph-CBNH2-1.4 and PDA-1.0.

[0075] Figure 8 The mechanical properties test results of Ph-CBNH2 modified epoxy resin. DETAILED DESCRIPTION

[0076] The raw materials and equipment used in the specific embodiments of the present invention are all known products and are obtained by purchasing commercially available products.

[0077] The present invention first synthesizes chlorinated carborane, uses chlorinated carborane as an intermediate, and introduces the target functional group into the carborane structure by using the substitution reaction of C-Cl bond with -NH2, -OH and -SH:

[0078]

[0079] The decaborane-acetonitrile complex of the present invention is prepared by the following method: 50 g of decaborane is dissolved in 80 ml of anhydrous acetonitrile, reacted at 80° C. for 12 h, the reaction system is filtered to obtain white crystals, and dried to obtain the decaborane-acetonitrile complex.

[0080] Example 1. Preparation of chlorinated carborane

[0081] The preparation method of chlorinated carborane is as follows:

[0082] Add 10g (0.05mol) of decaborane-acetonitrile complex (DBCN) and 6.14g (0.05mol) of 1,4-butyne dichloride to 80mL of toluene, and react at 120℃ for 8h. After the reaction, a dark clear solution is obtained. Add an appropriate amount of activated 4A molecular sieve and continue stirring for 30min to adsorb the by-products in the product. Transfer the solution to a separatory funnel and use the extraction method for post-treatment. Extract three times with saturated sodium chloride solution, collect the upper organic phase, remove the solvent to obtain dichlorocarbon borane. Using the extraction method, it takes about 3h from the end of the reaction to the final product dichlorocarbon borane, and 10.8g of product (yield 91%) can be obtained.

[0083] After obtaining a dark clear solution according to the above method, column chromatography is used for post-treatment: n-hexane and ethyl acetate are used as eluents (n-hexane: ethyl acetate = 5:1, ml ratio), and the 200-mesh silica gel powder is stirred evenly with the eluent and then filled into the silica gel column, and a pressure pump is used to pressurize and compact the silica gel powder. After quartz sand is laid on the top layer, the concentrated product is placed on it, and then rinsed with the eluent, and the effluent is collected from the lower test tube. After the reaction product is determined by thin layer chromatography analysis, the corresponding test tubes are merged, and the product is collected after the solvent is evaporated to obtain dichlorocarbon borane. Using column chromatography, it takes about 15 hours from the end of the reaction to the final production of dichlorocarbon borane, and 6.89g of product (yield 57.42%) can be obtained.

[0084] Example 2. Preparation of chlorinated carborane

[0085] Add 10g (0.05mol) of decaborane-acetonitrile complex (DBCN) and 9.23g (0.075mol) of 1,4-butyne dichloride to 80mL of toluene, and react at 100℃ for 8h. After the reaction, a dark clear solution is obtained. Add an appropriate amount of activated 4A molecular sieve and continue stirring for 30min to adsorb the by-products in the product. Transfer the solution to a separatory funnel and use the extraction method for post-treatment. Extract three times with saturated sodium chloride solution, collect the upper organic phase, remove the solvent to obtain dichlorocarbon borane. Using the extraction method, it takes about 3h from the end of the reaction to the final product dichlorocarbon borane, and 10.8g of product (yield 95%) can be obtained.

[0086] Example 3. Preparation of chlorinated carborane

[0087] Add 10g (0.05mol) of decaborane-acetonitrile complex (DBCN) and 18.45g (0.15mol) of 1,4-butyne dichloride to 80mL of toluene, and react at 80℃ for 20h. After the reaction, a dark clear solution is obtained. Add an appropriate amount of activated 4A molecular sieve and continue stirring for 30min to adsorb the by-products in the product. Transfer the solution to a separatory funnel and use the extraction method for post-treatment. Extract three times with saturated sodium chloride solution, collect the upper organic phase, remove the solvent to obtain dichlorocarbon borane. Using the extraction method, it takes about 3h from the end of the reaction to the final product dichlorocarbon borane, and 10.8g of product (yield 89%) can be obtained.

[0088] Simple post-treatment is the embodiment of the advanced nature of the method for preparing chlorocarborane. Most of the existing methods are currently column chromatography, which has low efficiency and high cost.

[0089] Example 4: Synthesis of aniline functionalized carborane (Ph-CBNH2) using chlorinated carborane as an intermediate

[0090] The preparation method of aniline functionalized carborane is as follows:

[0091] Add 12g (0.05mol) dichlorocarborane (CBCl2), 20.79g (0.10mol) N-(tert-butyloxycarbonyl)-1,4-phenylenediamine and 7.98g NaOH to 300mL N,N-dimethylformamide, and react at 100℃ for 8h. After the reaction, filter to obtain a yellow clear solution. Rotary evaporation to remove the solvent to obtain a yellow product, add dichloromethane to dissolve, and obtain a dark yellow solution. Remove the Boc protecting group: add 75g trifluoroacetic acid and react at 40℃ for 5h, add 25g NaOH and 150ml water, continue to react for 5h, cool down and the product precipitates to the wall of the single-necked flask, dry and collect to obtain anilino functionalized carborane.

[0092] Example 5: Synthesis of aniline functionalized carborane (Ph-CBNH2) using chlorinated carborane as an intermediate

[0093] The preparation method of aniline functionalized carborane is as follows:

[0094] Add 12g (0.05mol) dichlorocarborane (CBCl2), 20.79g (0.10mol) N-(tert-butyloxycarbonyl)-1,4-phenylenediamine and 15.96g NaOH to 300mL tetrahydrofuran, and react at 80℃ for 10h. After the reaction, filter to obtain a yellow clear solution. Rotary evaporation to remove the solvent to obtain a yellow product, add dichloromethane to dissolve, and obtain a dark yellow solution. Remove the Boc protecting group: add 75g trifluoroacetic acid and react at 40℃ for 5h, add 25g ammonia water, continue to react for 5h, cool down the product to precipitate on the wall of the single-necked flask, dry and collect to obtain anilino functionalized carborane.

[0095] Example 6: Synthesis of vinyl functionalized carborane (CBVi) using chlorinated carborane as an intermediate

[0096] The preparation method of vinyl functionalized carborane is as follows:

[0097] 2 g (0.0083 mol) of dichlorocarborane (CBCl2), 1.87 g (0.016 mol) of 1,6-heptadien-4-ol and 1.33 g of NaOH were added to 100 mL of tetrahydrofuran and reacted at 80 °C for 5 h. After the reaction, a yellow clear solution was obtained by filtration. The tetrahydrofuran solvent was removed by rotary evaporation and then dissolved in ethyl acetate. The solution was extracted with water for 3-5 times. The organic phases were combined and the solvent was removed by rotary evaporation to obtain the product vinyl functionalized carborane.

[0098] Example 7: Synthesis of vinyl functionalized carborane (CBVi) using chlorinated carborane as an intermediate

[0099] The preparation method of vinyl functionalized carborane is as follows:

[0100] 2 g (0.0083 mol) of dichlorocarborane (CBCl2), 1.87 g (0.016 mol) of 1,6-heptadien-4-ol and 3.62 g of NaOH were added to 100 mL of N,N-dimethylformamide, and the mixture was reacted at 80 °C for 10 h. After the reaction, a yellow clear solution was obtained by filtration. The tetrahydrofuran solvent was removed by rotary evaporation and then dissolved in ethyl acetate. The mixture was extracted with water for 3-5 times. The organic phases were combined and the solvent was removed by rotary evaporation to obtain the product vinyl functionalized carborane.

[0101] Example 8: Synthesis of aminated carborane containing methylene (Et-CBNH2) using chlorinated carborane as an intermediate

[0102] Add 10g (0.042mol) of dichlorocarborane (CBCl2), 14.55g (0.084mol) of N-tert-butyloxycarbonyl-1,3-propylenediamine and 6.65g of sodium hydroxide to 225mL of N,N-dimethylformamide, and react at 100℃ for 10h. After the reaction, filter to obtain a yellow clear solution. Rotary evaporation to remove the solvent gives a yellow product, which is dissolved in dichloromethane to obtain a dark yellow solution. Remove the Boc protecting group: add 75g of trifluoroacetic acid and react at 40℃ for 5h, add 25g of ammonia water, continue to react for 5h, cool and precipitate the product on the wall of a single-necked flask, dry and collect to obtain the aminated carborane containing methylene.

[0103] Example 9: Synthesis of aminated carborane containing methylene (Et-CBNH2) using chlorinated carborane as an intermediate

[0104] Add 10g (0.042mol) dichlorocarborane (CBCl2), 14.55g (0.084mol) N-tert-butyloxycarbonyl-1,3-propylenediamine and 6.65g triethylamine to 225mL N,N-dimethylformamide, and react at 100℃ for 10h. After the reaction, filter to obtain a yellow clear solution. Rotary evaporation to remove the solvent gives a yellow product, which is dissolved in dichloromethane to obtain a dark yellow solution. Remove the Boc protecting group: add 75g trifluoroacetic acid and react at 40℃ for 5h, add 25g ammonia water, continue to react for 5h, cool and precipitate the product on the wall of a single-necked flask, dry and collect to obtain the aminated carborane containing methylene.

[0105] Using chlorinated carborane as an intermediate, a variety of functionalized carboranes can be synthesized, which is a manifestation of the advancement of the present invention.

[0106] Example 10. Preparation of Et-CBNH2 modified epoxy resin

[0107] Et-CBNH2 synthesized in Example 9 is used as a curing agent, mAFG90 (4-(2,3-epoxypropoxy)-N,N-di(2,3-epoxypropyl)aniline, Adamas) is a matrix, 2-butanone is a solvent, fluorine-modified silicone is a defoaming agent (commercially available product, model KMT-2027, manufacturer Foshan Corning New Materials Co., Ltd.), and polyether-modified polysiloxane is a leveling agent (commercially available product, model KMT-5510S, manufacturer Foshan Corning New Materials Co., Ltd.) to prepare Et-CBNH2 modified epoxy resin. The raw material formula table of Et-CBNH2 modified epoxy resin is shown in Table 1. Et-CBNH2-1.0, 1.2 and 1.4 represent the equivalent ratio of the number of amino H atoms of the curing agent and the epoxy group.

[0108] In addition, the curing agent of the modified epoxy resin PD-1.0 in Table 1 is 1,3-propylenediamine, which lacks the carborane structure compared with Et-CBNH2.

[0109] Table 1. Raw material formula of epoxy resin

[0110]

[0111] Preparation method: Dissolve Et-CBNH2 in 2-butanone, add mAFG90, defoamer and leveling agent, stir at 80°C for 0.5 hours to obtain a uniform mixture. Place the mixture in front of the blade of the coating machine for coating, set the blade height to 100μm, the coating speed to 1s / cm, and the coating thickness to 100μm. Place the coated film in a blast oven for curing, first at 80°C for 1 hour, then at 140°C for 2 hours, and finally at 180°C for 1 hour. Finally, a carborane-modified epoxy resin is obtained. Replace the curing agent from Et-CBNH2 with 1,3-propylenediamine, and prepare PD-1.0 in the same way.

[0112] Example 11. Preparation of Ph-CBNH2 modified epoxy resin

[0113] Ph-CBNH2 modified epoxy resin was prepared using Ph-CBNH2 synthesized in Example 5 as a curing agent, mAFG90 (4-(2,3-epoxypropoxy)-N,N-di(2,3-epoxypropyl)aniline, Adamas) as a matrix, 2-butanone as a solvent, fluorine-modified silicone as a defoaming agent (commercially available product, model KMT-2027, manufactured by Foshan Corning New Materials Co., Ltd.), and polyether-modified polysiloxane as a leveling agent (commercially available product, model KMT-5510S, manufactured by Foshan Corning New Materials Co., Ltd.). The raw material formula table of Ph-CBNH2 modified epoxy resin is shown in Table 2. Ph-CBNH2-1.0, 1.2 and 1.4 represent the equivalent ratio of the number of amino H atoms of the curing agent and the epoxy group.

[0114] In addition, the curing agent of the modified epoxy resin PDA-1.0 in Table 2 is p-phenylenediamine.

[0115] Table 2. Raw material formula of epoxy resin

[0116]

[0117]

[0118] Preparation method: Dissolve Ph-CBNH2 in 2-butanone, add mAFG90, defoamer and leveling agent, stir at 80℃ for 0.5 hours to obtain a uniform mixture. Place the mixture in front of the blade of the coating machine for coating, set the blade height to 100μm, the coating speed to 1s / cm, and the coating thickness to 100μm. Place the coated film in a blast oven for curing, first at 80℃ for 1 hour, then at 140℃ for 2 hours, and finally at 180℃ for 1 hour. Finally, a carborane-modified epoxy resin is obtained. Replace the curing agent with p-phenylenediamine from Ph-CBNH2, and prepare PDA-1.0 in the same way.

[0119] The beneficial effects of the present invention are demonstrated below through specific test examples.

[0120] Test Example 1: Performance Study of Et-CBNH2 Modified Epoxy Resin

[0121] 1. Experimental methods

[0122] The performance test of the modified epoxy resin prepared in Example 10 was carried out:

[0123] (1) Mechanical properties testing method: Mechanical properties were tested using a tensile testing machine. The modified epoxy resin film was cut into 10 cm × 1 cm sheets, the tensile testing machine sensor was 100 N, and the stretching speed was 1 mm / min.

[0124] (2) The heat resistance test method is: using a thermogravimetric analyzer from NETZSCH to test. The test was conducted in air and nitrogen atmospheres, with a heating rate of 10°C / min and a test range of 35°C-800°C.

[0125] (3) The glass transition temperature is tested by using a dynamic mechanical analyzer produced by Waters China Ltd., with a heating rate of 10°C / min and a test temperature of 35°C-300°C.

[0126] (4) The neutron shielding performance test method is: using the data package developed by the European Organization for Nuclear Research to perform simulation calculations. The neutron energy is 0.1eV and the material thickness is 3mm; or the neutron energy is 1MeV and the material thickness is 40mm.

[0127] The test results of mechanical properties are as follows Figure 1 As shown by Figure 1 It can be seen that the introduction of Et-CBNH2 greatly improves the mechanical properties of epoxy resin. Compared with the modified epoxy resin prepared with 1,3-propylenediamine as the curing agent, the mechanical properties of the Et-CBNH2-modified epoxy resin are significantly improved, among which Et-CBNH2-1.4 is the best, with its tensile strength increased by 74.09% and elongation at break increased by 88.6%.

[0128] The test results of heat resistance are as follows: Figure 2 As shown by Figure 2 It can be seen that after Et-CBNH2 is introduced into the cross-linked network, the residual weight of the modified epoxy resin is significantly increased, and the thermal degradation process of the modified epoxy resin in air atmosphere changes significantly. The modified epoxy resin prepared with 1,3-propylenediamine as a curing agent degrades significantly at around 550°C, and the degradation at this stage is increased to nearly 800°C after the introduction of Et-CBNH2. Among them, Et-CBNH2-1.4 is the best.

[0129] The results of Tg test are as follows Figure 3 As shown by Figure 3 It can be seen that the introduction of Et-CBNH2 greatly improves the glass transition temperature of the epoxy resin. The Tg of the Et-CBNH2-1.4 material reaches about 275°C, which is nearly 100°C higher than that of the modified epoxy resin prepared using 1,3-propylenediamine as a curing agent, which is a significant improvement.

[0130] The simulation results of neutron shielding performance are shown in Figure 4 As shown, Figure 4 The energy of the first row of neutrons is 1MeV, and the material thickness is 40mm; the energy of the second row of neutrons is 0.1eV, and the material thickness is 3mm. Figure 4 It can be seen that compared with the modified epoxy resin prepared with 1,3-propylenediamine as the curing agent, the neutron shielding performance of the modified epoxy resin prepared with Et-CBNH2 as the curing agent is significantly improved, and the improvement of the neutron shielding performance is positively correlated with the introduction amount of Et-CBNH2.

[0131] Test Example 2: Performance Study of Ph-CBNH2 Modified Epoxy Resin

[0132] The performance of the modified epoxy resin prepared in Example 11 was tested:

[0133] (1) Mechanical properties testing method: Mechanical properties were tested using a tensile testing machine. The modified epoxy resin film was cut into 10 cm × 1 cm sheets, the tensile testing machine sensor was 100 N, and the stretching speed was 1 mm / min.

[0134] (2) The heat resistance test method is: using a thermogravimetric analyzer from NETZSCH to test. The test was conducted in air and nitrogen atmospheres, with a heating rate of 10°C / min and a test range of 35°C-800°C.

[0135] (3) The glass transition temperature is tested by using a dynamic mechanical analyzer produced by Waters China Ltd., with a heating rate of 10°C / min and a test temperature of 35°C-300°C.

[0136] The results of Tg test are as follows Figure 5 As shown by Figure 5 It can be seen that compared with the modified epoxy resin prepared using p-phenylenediamine as a curing agent, the introduction of Ph-CBNH2 greatly increased the glass transition temperature of the epoxy resin, and no obvious glass transition process occurred before 300°C. At the same time, compared with the glass transition temperature of the Et-CBNH2-modified epoxy resin (275°C), the glass transition temperature of the Ph-CBNH2-modified epoxy resin was significantly increased.

[0137] The test results of heat resistance are as follows: Figure 6 and Figure 7 As shown by Figure 6 and Figure 7 It can be seen that: compared with the modified epoxy resin prepared using paraphenylenediamine as a curing agent, the introduction of Ph-CBNH2 greatly improves the heat resistance of the epoxy resin. During the thermal degradation of the material, compared with PDA-1.0, the temperature required for Ph-CBNH2-1.4 to achieve a weight loss of 35wt% is 423.83°C (in nitrogen atmosphere) and 392.50°C (in air atmosphere) higher than that of PDA-1.0. The temperature required for Ph-CBNH2-1.4 at other weight loss ratios is also higher than that of PDA-1.0. Compared with the heat resistance of Et-CBNH2-modified epoxy resin, the heat resistance of Ph-CBNH2-modified epoxy resin is also significantly improved, as shown in the significant increase in thermal residual weight.

[0138] The test results of mechanical properties are as follows Figure 8 As shown by Figure 8 It can be seen that compared with the modified epoxy resin prepared using p-phenylenediamine as a curing agent, the introduction of Ph-CBNH2 greatly improves the mechanical properties of the epoxy resin. Figure 1 The mechanical properties test results of Et-CBNH2 modified epoxy resin show that the mechanical properties are significantly improved compared with Ph-CBNH2 modified epoxy resin, which is manifested in a significant improvement in tensile strength.

[0139] In summary, the present invention provides a new method for synthesizing functionalized carborane. First, dichlorocarborane is synthesized by an alkyne hydrogen addition method, and then purified by a simple water extraction method to obtain chlorinated carborane. The yield is high, the purification is simple, and it can be prepared in large quantities. With the chlorinated carborane as an intermediate product, a simple halogen substitution reaction can be used to connect the target functional group to the carborane structure to obtain a new functionalized carborane with different target functional groups. The method for preparing functionalized carborane of the present invention is simple and has great universality. The present invention adopts a new method for synthesizing functionalized carborane to synthesize a new amino-functionalized carborane, and the epoxy resin is modified by the new amino-functionalized carborane, which can significantly improve the heat resistance, mechanical properties and glass transition temperature of the epoxy resin. The modified epoxy resin can be used in various components in aviation equipment and in the protective layer of nuclear reactors, and has broad application prospects in the fields of aerospace and nuclear reactions.

Claims

1. A method for preparing an amine-functionalized carborane, characterized in that: It includes the following steps: (1) In a solvent, a decaborane-acetonitrile complex and a compound containing an alkynyl group and a halogen are reacted as raw materials; (2) after the reaction is completed, a solvent extraction method is used for post-treatment to obtain chlorinated carborane; (3) reacting the chlorinated carborane obtained in step (2), an amine compound and a base as raw materials in a solvent; (4) removing the Boc protecting group from the product obtained after the reaction in step (3) to obtain an amine-functionalized carborane.

2. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of the decaborane-acetonitrile complex to the compound containing an alkynyl group and a halogen is 1:(1-3); And / or, in step (1), the solvent is toluene; And / or, in step (1), the reaction temperature is 80-120° C., and the reaction time is 8-20 h; and / or, in step (3), the molar ratio of the chlorinated carborane to the amine compound is 1:(2-3); And / or, in step (3), the mass ratio of the chlorinated carborane to the base is 1:(0.5-1.5); And / or, in step (3), the solvent is N,N-dimethylformamide or tetrahydrofuran; And / or, in step (3), the reaction temperature is 80-100° C., and the reaction time is 8-10 h; And / or, in step (3), filtering after the reaction, removing the solvent, adding dichloromethane to dissolve and then removing the Boc protecting group; And / or, in step (4), the method for removing the Boc protecting group comprises the following steps: adding trifluoroacetic acid to the product of step 3) for reaction, then adding a mixture of alkali and water to continue the reaction, cooling until the product precipitates, and drying the product; Preferably, In step (1), the compound containing an alkynyl group and a halogen is 1,4-butyne dichloro, di(4-bromophenyl)alkyne, 4-bromophenylacetylene or 3-chloropropyne; And / or, in step (3), the amine compound is N-(tert-butyloxycarbonyl)-1,4-phenylenediamine or N-tert-butyloxycarbonyl-1,3-propylenediamine; And / or, in step (4), the temperature of adding trifluoroacetic acid to react is 40 to 60° C., and the reaction time is 1 to 5 hours; And / or, in step (4), the mixture of alkali and water is a mixture of sodium hydroxide and water or aqueous ammonia; And / or, in step (4), the mixture of alkali and water is added and the reaction time is continued for 1 to 5 hours.

3. The preparation method according to claim 2, characterized in that: In step (1), the decaborane-acetonitrile complex is prepared using decaborane and anhydrous acetonitrile as raw materials; the mass volume ratio of decaborane to anhydrous acetonitrile is (5-500) g: (10-2000) ml; Preferably, in step (1), the method for preparing the decaborane-acetonitrile complex comprises the following steps: dissolving decaborane in anhydrous acetonitrile, filtering after the reaction, to obtain; More preferably, the reaction temperature is 50-200° C., and the reaction time is 1-20 h.

4. The preparation method according to claim 1, characterized in that: In step (2), the extraction method comprises the following steps: 1) After the reaction is completed, add activated molecular sieves and stir, then add saturated salt solution to the solution for extraction; 2) Collect the upper organic phase after extraction and remove the solvent; Preferably, In step 1), the molecular sieve is a 4A molecule; And / or, in step 1), the saturated salt solution is a saturated sodium chloride solution; And / or, in step 1), the extraction is performed 1 to 10 times.

5. An amine-functionalized carborane, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 4.

6. Use of the amine-functionalized carborane according to claim 5 as a curing agent in the preparation of resin-based composite materials.

7. A resin-based composite material, characterized in that: It is prepared from the following raw materials in the following weight ratio: 1-10 parts of resin matrix, 1-5 parts of the amine-functionalized carborane according to claim 6, 0.01-0.1 parts of defoaming agent, and 0.01-0.1 parts of leveling agent; Preferably, It is prepared from the following raw materials in the following weight ratio: 5 parts of resin matrix, 2.5-3.5 parts of the amine-functionalized carborane according to claim 6, 0.05 parts of defoaming agent, and 0.05 parts of leveling agent; Alternatively, it is prepared from the following raw materials in the following weight ratio: 3 parts of resin matrix, 1.82-2.55 parts of the amine-functionalized carborane according to claim 6, 0.05 parts of defoaming agent, and 0.05 parts of leveling agent.

8. The resin-based composite material according to claim 7, characterized in that: The resin matrix is ​​epoxy resin, and the epoxy resin is preferably mAFG-90; And / or, the defoaming agent is fluorine-modified silicone; And / or, the leveling agent is polyether-modified polysiloxane.

9. A method for preparing the resin-based composite material according to claim 7 or 8, characterized in that: It includes the following steps: (A) dissolving the amine-functionalized carborane according to claim 6 in a solvent, adding a resin matrix, a defoaming agent and a leveling agent, and stirring to obtain a uniform mixture; (B) coating the mixture; (C) The coating is cured to obtain the product; Preferably, In step (A), the solvent is methanol, ethanol, acetone, n-propanol, isopropanol, ethyl acetate or 2-butanone; And / or, in step (A), the stirring temperature is 50 to 100° C., and the stirring time is 0.5 to 1 hour; And / or, in step (B), the coating machine blade height is 20-200 μm, the coating thickness is 10-150 μm, and the coating speed is 1-20 s / cm; And / or, in step (C), the curing conditions are 80-100° C. for 0.5-5 hours, then 120-160° C. for 1-5 hours, and finally 170-180° C. for 1-5 hours.

10. Use of the resin-based composite material according to claim 7 or 8 in preparing various components in aviation equipment and devices used in nuclear reactor protective layers.

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