CN107459648B - A kind of synthetic method of high temperature resistant carbon borane polyimide resin - Google Patents

Abstract

The invention relates to the technical field of resin synthesis, and particularly discloses a synthesis method of high-temperature resistant carborane-containing polyimide resin, which comprises the following steps: the method comprises the following steps: 4-ethynyltoluene is synthesized into 4-carborane toluene; step two: 4-carborane toluene to synthesize 2, 6-dinitro-4-carborane toluene; step three: 2, 6-binitro-4-carborane toluene is synthesized into 2, 6-diamino-4-carborane toluene; step four: 2, 6-diamino-4-carborane toluene to synthesize modified polyimide resin. The invention adopts phenylacetylene-terminated thermosetting polyimide resin as a matrix, carries out molecular design on monomer diamine to synthesize m-phenylenediamine containing carborane boron cage structure, and then carries out polymerization reaction with anhydride and a terminating agent to finally obtain the modified polyimide resin, wherein the maximum use temperature of the polymer can reach 600 ℃, and the polymer has excellent oxidation stability.

Description

A kind of synthetic method of high temperature resistant carbon borane polyimide resin

technical field

The invention belongs to the technical field of resin synthesis, in particular to a method for synthesizing a high temperature resistant carbon-containing borane polyimide resin.

Background technique

With the development of modern industrial technology, traditional metal materials have been unable to meet the application requirements of special models in aviation and aerospace, with high specific strength and specific stiffness, strong designability, fatigue resistance, good corrosion resistance and special electromagnetic properties. A class of advanced resin-based composite materials with high-performance fibers as reinforcements came into being. The use of advanced resin matrix composites instead of metal materials such as aluminum alloys can significantly reduce structural weight. Compared with traditional structural materials such as steel and aluminum alloys, the density of resin-based composites is about 1/5 of that of steel and 1/2 of that of aluminum alloys, and its specific strength and specific modulus are significantly higher than those of steel and aluminum alloys. The development of solid rocket motors, main battle tanks, satellites, strategic missiles, high-performance destroyers, submarine radomes and other weapon systems is inseparable from advanced composite material technology.

Polyimide is a resin matrix of advanced composite materials with excellent performance and high temperature resistance, which is widely used in aerospace, aviation, microelectronics and other industrial fields. The most used thermosetting polyimide is norbornene-terminated or phenylethynyl-terminated, and it has been developed to the fourth-generation polyimide composite material with a temperature resistance of 450 °C, forming a four-generation polyimide from 280-450 °C. The high temperature resistant polyimide composite material system. However, with the continuous improvement of material requirements in the aerospace field, it is urgent to develop a resin system that can withstand high temperatures above 450 °C.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for synthesizing a high temperature resistant carborane-containing polyimide resin, which can significantly improve the temperature resistance of the polymer.

The technical scheme of the present invention is as follows:

A method for synthesizing high temperature resistant carbon-containing borane polyimide resin, characterized in that: comprising the following steps:

Chemical formula:

Wherein, compound 1 is 4-ethynyltoluene, compound 2 is 4-carboranetoluene, compound 3 is 2,6-dinitro-4-carboranetoluene, and compound 4 is 2,6-diamino-4 - carborane toluene;

Step 1: Compound 1 is synthesized into compound 2;

Step 2: Compound 2 is synthesized into compound 3;

Step 3: compound 3 to synthesize compound 4;

Step 4: Compound 4 synthesizes modified polyimide resin, the specific synthetic route:

In step 1, compound 1, B ₁₀ H ₁₂ (CH ₃ CN) ₂ and toluene were added to the three-necked flask in turn, and compound 1 and B ₁₀ H ₁₂ (CH ₃ CN) ₂ could be completely dissolved in toluene, and then at 100-120 After 20-24 hours of reaction at ℃, the heating is stopped to end the reaction;

Then, toluene was distilled off under reduced pressure at 60-90° C., and then methanol was added for recrystallization to obtain compound 2 as white crystals.

Step 2, take compound 2 and place it in a three-necked flask, then add methylene chloride, stir mechanically, and then dropwise add fuming nitric acid and concentrated sulfuric acid in sequence under ice-water bath conditions, and place the three-necked flask in the The reaction was continued for 3-6 h at room temperature, and then the reaction was terminated to obtain a mixture;

The mixture was poured into ice water, and separated with a separating funnel to obtain an aqueous phase solution and an oil phase solution, wherein the aqueous phase solution was extracted with dichloromethane, and then combined with the oil phase solution;

The combined solution was washed with saturated sodium bicarbonate solution until bubbles appeared; the solution was washed with saturated brine until neutral, then dried with anhydrous magnesium sulfate, and the dried solution was distilled under reduced pressure with a rotary evaporator, Then ethanol was added for recrystallization, and finally compound 3 was obtained as a pale yellow solid.

In step 3, compound 3, SnCl ₂ ·2H ₂ O, ethanol and concentrated hydrochloric acid are sequentially added to the three-necked flask, and after stirring and reacting at room temperature for 1-2 hours, the temperature is raised to 70-100° C. and reacting for 3-5 hours to obtain a reaction solution;

After cooling the reaction solution to room temperature, the reaction solution was adjusted to pH=7～10 with saturated sodium bicarbonate solution to obtain a mixed solution, and then the mixed solution was extracted with ethyl acetate to obtain an extract;

The obtained extract was dried with anhydrous magnesium sulfate, and then ethyl acetate in the extract was removed by distillation under reduced pressure, and then ethanol was added for recrystallization, and finally white solid compound 4 was obtained.

Step 4, add 3,3',4,4'-benzophenone tetraacid dianhydride, compound 4 and DMAc solvent, 3,3',4,4'-benzophenone tetraacid dianhydride successively into the three-necked flask And compound 4 can be completely dissolved in DMAc solvent; then nitrogen is passed into the three-necked flask, and a drying tube is added to the three-necked flask, and after mechanical stirring for 2 to 4 hours, the end capping agent 4-phenylacetylene phthalic anhydride is added, and it is continued at room temperature. The reaction is carried out for 18-24 hours to obtain a viscous light yellow transparent polyamic acid solution;

Then, toluene is added to the three-necked flask, the temperature is raised to 150-180 °C, the toluene is taken out by azeotropic dehydration, and the reaction is continued at 150-180 °C for 8-10 hours, and the reaction is terminated to obtain a reaction solution;

The reaction solution was poured into ethanol for precipitation, and the precipitation was filtered and dried to obtain a pale yellow powdery polyimide oligomer.

In the described step 1, add Ag compound 1, Bg B ₁₀ H ₁₂ (CH ₃ CN) ₂ and C g toluene, and obtain Mg white crystal compound 2;

Among them, A:B=1:1.5～1:3, A:C=1:17～1:20, A:M=1:1～1:1.5.

In the described step 2, add Dg compound 2 and Eg dichloromethane, finally obtain Ng light yellow solid compound 3;

Among them, D:E=1:1.5～1:2, D:N=1:1～1:1.5.

In described step 2, add Fg fuming nitric acid and Gg vitriol oil;

Among them, D:F=1:0.2～1:0.4, D:G=1:1～1:4.

In the described step 3, add Hg compound 3, 1g SnCl ₂ ·2H ₂ O, Jg 95～98% concentration of ethanol and Kg 30～40% concentration concentrated hydrochloric acid, finally obtain Pg white solid compound 4;

Among them, H:I=1:0.5～1:1, H:J=1:5～1:10, H:K=1:0.5～1:1.

In the described step 4, respectively add Qg of 3,3',4,4'-benzophenone tetracarboxylic dianhydride, Rg of compound 4, Sg of DMAc solvent, Vg of the capping agent 4-phenylacetylene phthalic anhydride, Wg of toluene, finally obtain Yg pale yellow powdery polyimide oligomer;

Among them, Q:R=1:1～1:2, Q:S=1:3～1:4, Q:V=1:1～1:2, Q:W=1:0.5～1:1.

The remarkable effect of the present invention is:

(1) The carborane used in the present invention has an icosahedral cage structure, and the superaromaticity and strong electron-withdrawing properties of its three-dimensional structure make its derivatives have excellent heat resistance and oxidation stability.

(2) The disintegration of the boron cage at high temperature can absorb energy and generate a large amount of boron trioxide, which can protect the polymer. The invention introduces the carborane structure into the polymer, which can improve the temperature resistance of the polymer by more than 100°C, and can also improve the oxidation stability of the polymer in the air.

(3) The present invention adopts the thermosetting polyimide resin end-capped with phenylacetylene as the matrix, carries out molecular design on its monomer diamine, and synthesizes the m-phenylenediamine containing carborane boron cage structure, and then combines with acid anhydride and The end-capping agent is polymerized, and finally a modified polyimide resin is obtained, and the maximum service temperature of the polymer can reach 600°C.

(4) The DMA test of the modified polyimide resin synthesized by the present invention can keep the modulus unchanged at 0-600°C.

Description of drawings

Fig. 1 is the infrared test chart of compound 2, compound 3 and compound 4;

Fig. 2 is the infrared spectrogram of the modified polyimide oligomer resin;

Fig. 3 is the modified polyimide oligomer resin DSC schematic diagram;

Fig. 4 is the schematic diagram of thermal weight loss in argon gas of polyimide resin polymer after complete curing and modification;

Fig. 5 is the DMA test chart of the modified polyimide resin casting body.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

A method for synthesizing a high temperature resistant carbon-containing borane polyimide resin of the present invention comprises the following steps:

Chemical formula:

Wherein, compound 1 is 4-ethynyltoluene, compound 2 is 4-carboranetoluene, compound 3 is 2,6-dinitro-4-carboranetoluene, and compound 4 is 2,6-diamino-4 -Carborane toluene.

(1) Compound 1 to synthesize compound 2

In the three-necked flask a, compound 1 of Ag, B ₁₀ H ₁₂ (CH ₃ CN) ₂ of Bg and C g of toluene were successively added, and compound 1 and B ₁₀ H ₁₂ (CH ₃ CN) ₂ could be completely dissolved in toluene, Wherein A:B=1:1.5～1:3, A:C=1:17～1:20, and then react at 100～120° C. for 20～24h and then stop heating to end the reaction.

Then, toluene was distilled off under reduced pressure at 60-90° C., and then recrystallized by adding methanol, finally obtaining Mg white crystal compound 2, wherein A:M=1:1～1:1.5.

(2) Compound 2 Synthesis of Compound 3 Take Dg of compound 2 and place it in a three-necked flask b, then add Eg of dichloromethane, and stir mechanically evenly, wherein D:E=1:1.5～1:2. Then, under ice-water bath conditions, Fg fuming nitric acid and Gg concentrated sulfuric acid were added dropwise at a rate of 1 drop/sec to 2 drops/sec, wherein D:F=1:0.2～1:0.4, D:G=1:1 ~1:4. After the dropwise addition is completed and the stirring is uniform, the three-necked flask b is placed at room temperature to continue the reaction for 3 to 6 hours, and then the reaction is terminated to obtain a mixture.

The mixture was poured into ice water, and separated with a separating funnel to obtain an aqueous phase solution and an oil phase solution; the aqueous phase solution was extracted with dichloromethane, and then combined with the oil phase solution. The combined solution was washed with saturated sodium bicarbonate solution until bubbles appeared; the solution was washed with saturated brine until neutral, and then dried over anhydrous magnesium sulfate. The dried solution was distilled under reduced pressure with a rotary evaporator, and then recrystallized by adding ethanol to obtain Ng light yellow solid compound 3, wherein D:N=1:1～1:1.5.

(3) Synthesis of compound 3 to compound 4

In the three-necked flask c, add Hg compound 3, Ig SnCl ₂ ·2H ₂ O, Jg 95～98% ethanol and Kg 30～40% concentrated hydrochloric acid successively, wherein H:I=1:0.5～1:1 , H:J=1:5～1:10, H:K=1:0.5～1:1; after stirring and reacting at room temperature for 1～2h, the temperature was raised to 70～100°C and reacted for 3～5h to obtain a reaction solution.

After cooling the reaction solution to room temperature, the reaction solution was adjusted to pH=7-10 with saturated sodium bicarbonate solution to obtain a mixed solution, and then the mixed solution was extracted with ethyl acetate to obtain an extract. The obtained extract was dried with anhydrous magnesium sulfate, then the ethyl acetate in the extract was removed by distillation under reduced pressure, and then ethanol was added for recrystallization to finally obtain Pg white solid compound 4.

(4) Compound 4 to synthesize modified polyimide resin

Specific synthetic route:

In the three-necked flask d, Q g of 3,3',4,4'-benzophenone tetracarboxylic dianhydride, compound 4 of R g and DMAc solvent of S g were sequentially added to make 3,3',4,4' -The benzophenone tetraacid dianhydride and compound 4 can be completely dissolved in the DMAc solvent; then nitrogen is passed into the three-necked flask d, and a drying tube is added to the three-necked flask d, and after the reaction is mechanically stirred for 2 to 4 hours, the sealing of Vg is added. End agent 4-phenylacetylene phthalic anhydride, continue to react at room temperature for 18～24h to obtain a light yellow transparent polyamic acid solution with viscosity wherein Q:R=1:1～1:2, Q:S=1:3～ 1:4, Q:V=1:1～1:2.

Then, Wg of toluene is added to the three-necked flask d, the temperature is raised to 150-180° C., toluene is taken out by azeotropic dehydration, and the reaction is continued at 150-180° C. for 8-10 hours to complete the reaction to obtain a reaction solution. The reaction solution was poured into ethanol for precipitation, and the precipitate was filtered with suction and dried to obtain a pale yellow powdery polyimide oligomer Yg, wherein Q:W=1:0.5-1:1.

Example 1

In a 250 mL three-necked flask, 5.2 g of 4-ethynyltoluene, 14.8 g of B ₁₀ H ₁₂ (CH ₃ CN) ₂ and 100 g of toluene were sequentially added, and the reaction was completed at 110° C. for 20 h. Toluene was distilled off under reduced pressure at 70°C, followed by recrystallization by adding methanol to obtain 5.6 g of compound 2 as white crystals.

5.6 g of compound 2 was placed in a 100 mL three-necked flask, 10 g of dichloromethane was added, and mechanical stirring was performed uniformly. Then, 2 g of fuming nitric acid and 20 g of concentrated sulfuric acid were successively added dropwise at a rate of 1 drop/second in an ice-water bath. After the dropwise addition, the reaction was continued for 3 hours at room temperature, and the reaction was terminated to obtain a mixture. The mixture was poured into ice water and separated with a separating funnel to obtain an aqueous phase solution and an oil phase solution, wherein the aqueous phase solution was extracted with dichloromethane and then combined with the oil phase solution, and then the solution was washed with saturated sodium bicarbonate until Bubbles were generated; the solution was washed with saturated brine until neutral, and then dried over anhydrous magnesium sulfate. The dried solution was distilled under reduced pressure with a rotary evaporator, and then recrystallized by adding ethanol to finally obtain 6.9 g of compound 3 as a pale yellow solid.

In a 250 mL three-necked flask, 6.9 g of compound 3, 5 g of SnCl ₂ ·2H ₂ O, 50 g of 98% ethanol and 5 g of 35% concentrated hydrochloric acid were sequentially added, and the reaction was stirred at room temperature for 1 h, and then heated to 80 °C for 3 h. Then, the reaction was terminated to obtain a reaction solution. After cooling the reaction solution to room temperature, the reaction solution was adjusted to pH=9 with saturated sodium bicarbonate solution to obtain a mixed solution, and the mixed solution was extracted with ethyl acetate to obtain an extract. The obtained extract was dried with anhydrous magnesium sulfate, and then ethyl acetate in the extract was removed by distillation under reduced pressure, and then ethanol was added for recrystallization to finally obtain 5.3 g of white solid compound 4.

5.3 g of 3,3',4,4'-benzophenone tetraacid dianhydride, 8.6 g of compound 4 and 20 g of DMAc solvent were sequentially added to a 250 mL three-necked flask. Then, nitrogen was passed into the three-necked flask, and a drying tube was added to the three-necked flask. After the reaction was mechanically stirred for 2 hours, 8.1 g of the end-capping agent 4-phenylacetylene phthalic anhydride was added, and the reaction was continued at room temperature for 20 hours to obtain a light yellow transparent substance with viscosity. polyamic acid solution. Then, 5 g of toluene was added to the three-necked flask, the temperature was raised to 170° C., the toluene was taken out by azeotropic dehydration, and then the reaction was continued at 170° C. for 9 hours to complete the reaction to obtain a reaction solution. The reaction solution was poured into a sufficient amount of ethanol to precipitate, and the precipitate was filtered and dried to obtain a pale yellow powdery polyimide oligomer. Specific synthesis steps:

Example 2

In a 500 mL three-necked flask, 11 g of 4-ethynyltoluene, 20 g of B ₁₀ H ₁₂ (CH ₃ CN) ₂ and 200 g of toluene were sequentially added, and the reaction was completed at 110° C. for 24 h. Toluene was distilled off under reduced pressure at 80°C, and then methanol was added for recrystallization to obtain 12 g of compound 2 as white crystals.

Take 12 g of compound 2 and put it in a 200 mL three-necked flask, add 20 g of dichloromethane, and stir mechanically evenly. Then, 3 g of fuming nitric acid and 25 g of concentrated sulfuric acid were added dropwise at a rate of 2 drops/second in an ice-water bath. After the dropwise addition, the reaction was continued at room temperature for 5 hours, and the reaction was terminated to obtain a mixture. The mixture was poured into ice water and separated with a separating funnel to obtain an aqueous phase solution and an oil phase solution, wherein the aqueous phase solution was extracted with dichloromethane and then combined with the oil phase solution, and then the solution was washed with saturated sodium bicarbonate until There are bubbles; then wash the solution with saturated brine to neutrality, then dry the solution with anhydrous magnesium sulfate, distill the dried solution under reduced pressure with a rotary evaporator, add ethanol for recrystallization, and finally obtain 15g of pale yellow solid compound 3 .

In a 500 mL three-necked flask, 15 g of compound 3, 10 g of SnCl ₂ ·2H ₂ O, 100 g of 99% ethanol and 10 g of 30% diluted hydrochloric acid were sequentially added, and after stirring at room temperature for 1 hour, the temperature was raised to 90° C. for 4 hours, and then ended The reaction was carried out to obtain a reaction solution. After cooling the reaction solution to room temperature, the reaction solution was adjusted to pH=9 with saturated sodium bicarbonate solution to obtain a mixed solution, and the mixed solution was extracted with ethyl acetate to obtain an extract. The obtained extract was dried with anhydrous magnesium sulfate, then ethyl acetate in the extract was removed by distillation under reduced pressure, and ethanol was added for recrystallization to finally obtain 12 g of white solid compound 4.

Into a 500 mL three-necked flask, 12 g of 3,3',4,4'-benzophenone tetraacid dianhydride, 20 g of compound 4 and 40 g of DMAc solvent were sequentially added. Then, nitrogen was passed into the three-necked flask, and a drying tube was added to the three-necked flask. After mechanical stirring for 3 hours, 20 g of end-capping agent 4-phenylacetylene phthalic anhydride was added, and the reaction was continued at room temperature for 20 hours to obtain a light yellow transparent polymer with viscosity. amic acid solution. Then, 10 g of toluene was added to the three-necked flask, the temperature was raised to 170° C., and the toluene was taken out by azeotropic dehydration. Then, the reaction was continued at 170° C. for 9 hours, and the reaction was terminated to obtain a reaction solution. The reaction solution was poured into a sufficient amount of ethanol to precipitate, and the precipitate was filtered and dried to obtain a pale yellow powdery polyimide oligomer.

Claims (10)

1. A synthesis method of high temperature resistant carborane-containing polyimide resin is characterized by comprising the following steps: the method comprises the following steps:

the chemical formula is as follows:

wherein the compound 1 is 4-ethynyltoluene, the compound 2 is 4-carborane toluene, the compound 3 is 2, 6-dinitro-4-carborane toluene, and the compound 4 is 2, 6-diamino-4-carborane toluene;

the method comprises the following steps: compound 1 compound 2 is synthesized;

step two: compound 2 compound 3 is synthesized;

step three: compound 3 compound 4 was synthesized;

step four: the compound 4 is synthesized into modified polyimide resin, and the specific synthetic route is as follows:

2. the method for synthesizing high temperature resistant carborane-containing polyimide resin as claimed in claim 1, wherein: step one, sequentially adding a compound 1 and a compound B into a three-neck flask₁₀H₁₂(CH₃CN)₂And toluene, Compounds 1 and B₁₀H₁₂(CH₃CN)₂The catalyst can be completely dissolved in toluene, and then the reaction is carried out for 20-24 h at 100-120 ℃, and then the heating is stopped, and the reaction is finished;

followed by removing toluene by distillation under reduced pressure at 60 to 90 ℃ and then adding methanol to recrystallize, thereby obtaining compound 2 as white crystals.

3. The method for synthesizing high temperature resistant carborane-containing polyimide resin as claimed in claim 1, wherein: placing the compound 2 in a three-neck flask, adding dichloromethane, mechanically stirring uniformly, then sequentially dropwise adding fuming nitric acid and concentrated sulfuric acid under the ice-water bath condition, after dropwise adding and uniformly stirring, placing the three-neck flask to room temperature, continuing to react for 3-6 hours, and then finishing the reaction to obtain a mixture;

pouring the mixture into ice water, separating by using a separating funnel to obtain a water phase solution and an oil phase solution, extracting the water phase solution by using dichloromethane, and then combining the water phase solution and the oil phase solution;

washing the combined solution with saturated sodium bicarbonate solution until bubbles are generated; washing the solution with saturated saline solution to neutrality, drying with anhydrous magnesium sulfate, distilling the dried solution with a rotary evaporator under reduced pressure, adding ethanol, and recrystallizing to obtain light yellow solid compound 3.

4. The method for synthesizing high temperature resistant carborane-containing polyimide resin as claimed in claim 1, wherein: step three, sequentially adding the compound 3 and SnCl into a three-neck flask₂·2H₂O, ethanol and concentrated hydrochloric acid,stirring and reacting for 1-2 h at room temperature, and then heating to 70-100 ℃ to react for 3-5 h to obtain a reaction solution;

cooling the reaction liquid to room temperature, adjusting the pH of the reaction liquid to 7-10 by using a saturated sodium bicarbonate solution to obtain a mixed solution, and extracting the mixed solution by using ethyl acetate to obtain an extraction liquid;

the obtained extract was dried over anhydrous magnesium sulfate, and then ethyl acetate in the extract was removed by distillation under reduced pressure, followed by addition of ethanol for recrystallization to obtain a white solid compound 4.

5. The method for synthesizing high temperature resistant carborane-containing polyimide resin as claimed in claim 1, wherein: step four, sequentially adding 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride, a compound 4 and a DMAc solvent into a three-neck flask, wherein the 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride and the compound 4 can be completely dissolved in the DMAc solvent; introducing nitrogen into the three-neck flask, adding a drying tube on the three-neck flask, mechanically stirring for reacting for 2-4 h, adding a terminal-blocking agent 4-phenylacetylene phthalic anhydride, and continuously reacting for 18-24 h at room temperature to obtain a viscous light yellow transparent polyamide acid solution;

adding methylbenzene into a three-neck flask, heating to 150-180 ℃, taking out the methylbenzene by azeotropic dehydration, continuing to react for 8-10 hours at 150-180 ℃, and ending the reaction to obtain a reaction solution;

and pouring the reaction liquid into ethanol for precipitation, performing suction filtration and drying the precipitate to obtain a light yellow powdery polyimide oligomer.

6. The method for synthesizing high temperature carborane-containing polyimide resin as claimed in claim 2, wherein: in the first step, Ag compound 1 and B of Bg are added₁₀H₁₂(CH₃CN)₂And C g toluene, and yielded Mg white crystalline Compound 2;

wherein A: B is 1: 1.5-1: 3, A: C is 1: 17-1: 20, and A: M is 1: 1-1: 1.5.

7. The method for synthesizing high temperature carborane-containing polyimide resin as claimed in claim 3, wherein: in the second step, Dg compound 2 and Eg dichloromethane are added to obtain Ng pale yellow solid compound 3 finally;

wherein D is 1: 1.5-1: 2, and D is N is 1: 1-1: 1.5.

8. The method of synthesizing a high temperature carborane-containing polyimide resin as claimed in claim 7, wherein: in the second step, Fg fuming nitric acid and Gg concentrated sulfuric acid are added;

wherein D is F-1: 0.2-1: 0.4, and D is G-1: 1-1: 4.

9. The method for synthesizing high temperature carborane-containing polyimide resin as claimed in claim 4, wherein: in the third step, Hg compound 3 and Ig SnCl are added₂·2H₂O, Jg 95-98% ethanol and Kg of concentrated hydrochloric acid with the concentration of 30-40%;

wherein H: I is 1: 0.5-1: 1, H: J is 1: 5-1: 10, and H: K is 1: 0.5-1: 1.

10. The method for synthesizing high temperature carborane-containing polyimide resin as claimed in claim 5, wherein: in the fourth step, respectively adding Qg of 3,3 ', 4, 4' -benzophenonetetracarboxylic dianhydride, Rg of compound 4, Sg of DMAc solvent, Vg of end capping agent 4-phenylacetylene phthalic anhydride and Wg of toluene;

wherein R is 1: 1-1: 2, S is 1: 3-1: 4, V is 1: 1-1: 2, and W is 1: 0.5-1: 1.

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