Carbon fiber / polyimide composite material with self-repairing function and preparation method thereof
By preparing carbon fiber/polyimide composites containing diamine cystamine containing aliphatic disulfide bonds and modified carbon fiber/graphene oxide, self-repair of bicycle parts was achieved, solving the complex problems of traditional repair methods and improving the self-repair ability and mechanical stability of the material.
Patent Information
- Application Number
- CN202511098984.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-06
- Publication Date
- 2025-10-10
AI Technical Summary
Existing carbon fiber composite materials are easily damaged in bicycle components due to impact or scratches. Traditional repair methods are complex and difficult to restore the original mechanical properties of the material, posing a safety hazard, especially in competitive cycling or outdoor adventure scenarios.
A polyamic acid solution was prepared using diamine cystamine, 4,4'-diaminodiphenyl disulfide and bisphenol A diether dianhydride containing aliphatic disulfide bonds, and then compounded with modified carbon fiber and modified graphene oxide to form a carbon fiber/polyimide composite material with self-repairing function. The dynamic exchange reaction of disulfide bonds was used to achieve self-repair of the material.
When damaged, the material can restore its mechanical properties through molecular chain migration and rearrangement, improve self-repair efficiency, enhance interface bonding and material toughness, extend service life and reduce maintenance costs.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of self-repairing composite materials, and in particular to a carbon fiber / polyimide composite material with a self-repairing function and a preparation method thereof. Background Art
[0002] In bicycle manufacturing, carbon fiber composites have become the mainstream material for core components such as frames and wheels due to their lightweight, high strength, and excellent fatigue resistance. However, carbon fiber materials are prone to structural damage due to impact, scratches, or microcrack propagation over long-term use. Traditional repair methods, such as surface coating repairs or partial carbon fiber replacement, are complex, costly, and difficult to restore to the original mechanical properties of the material. This is particularly true in competitive cycling or outdoor adventure scenarios, where tiny cracks in components such as frames can expand gradually due to inability to repair them in a timely manner, ultimately posing a safety hazard.
[0003] With the development of lightweight and intelligent bicycles, the industry has an increasingly urgent demand for the self-sensing and self-repairing functions of carbon fiber materials. There is an urgent need to develop a new composite material that combines efficient self-repair capabilities and mechanical stability to extend the service life of the material, reduce maintenance costs and improve riding safety. Summary of the Invention
[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a carbon fiber / polyimide composite material with self-repairing function and a preparation method thereof, which can effectively solve the problem of insufficient performance of the self-repairing polyimide composite material in the prior art.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A carbon fiber / polyimide composite material with self-repairing function, the carbon fiber / polyimide composite material with self-repairing function is composed of the following components: polyamic acid solution, modified carbon fiber and modified graphene oxide; The polyamic acid solution is prepared with diamine cystamine containing aliphatic disulfide bonds, 4,4'-diaminodiphenyl disulfide and bisphenol A diether dianhydride as main raw materials; The modified carbon fiber is prepared by chemically grafting polycarbosilane onto the surface of the carbon fiber; The modified graphene oxide is prepared by modifying graphene oxide with polyetheramine.
[0006] Furthermore, the preparation steps of the diamine cystamine containing aliphatic disulfide bonds are: Step A, weigh 30-32 g cystamine dihydrochloride into 100 mL deionized water, stir at 300-400 r / min for 10 min, then add 45-48 mL potassium hydroxide solution with a concentration of 10 mol / L at a drop rate of 1 drop / s, and magnetically stir at 500-600 r / min for 1 h, and the obtained is the reaction component; Step B, extract the reaction component with dichloromethane, after 3 times of extraction, collect all the organic phases, add excess anhydrous magnesium sulfate, dry for 12 h, filter and rotary evaporate, and the obtained is cystamine containing aliphatic disulfide bond.
[0007] Further, the preparation step of the polyamic acid solution is: Step 1, weigh 2-3 g cystamine containing aliphatic disulfide bond, 4-5 g 4,4'-diamino diphenyl disulfide and 50 mL N,N-dimethylacetamide into a flask, mix and stir, and mark as a mixed component; Step 2, add 8-9 g bisphenol A type diether dianhydride to the mixed component in 4-5 times, mechanically stir for 12 h, and the obtained is a polyamic acid solution.
[0008] Further, the mixing and stirring method in step 1 is stirring at 500-600 r / min at room temperature for 30 min, and the stirring speed of mechanical stirring in step 2 is 300-400 r / min.
[0009] Further, the preparation step of the modified carbon fiber is: Step i, immerse 10-12 g carbon fiber in acetone for 12 h, remove the filtrate and dry, then add 0.5-0.8 g allyl dimethyl chlorosilane into 150 mL toluene, stir and dissolve, then heat in a water bath at 40℃ for 24 h, and the obtained is a reaction component; Step ii, weigh 2-3 g polycarbosilane into 50 mL toluene, disperse uniformly, and the obtained is a polycarbosilane component; Step iii, add 0.2-0.3 g dichlorotitanocene to the reaction component at a temperature of 75℃, add the polycarbosilane component after 10 min of reaction, mechanically react for 24 h, remove the filtrate by suction filtration and dry, then place in a nitrogen atmosphere and treat in a tube furnace at 450℃ for 1 h, and the obtained is a modified carbon fiber.
[0010] Further, the stirring and dissolving method in step i is stirring at 400-500 r / min for 30 min, the uniformly dispersing method in step ii is stirring at 500-600 r / min for 10 min, and the drying method in step iii is drying at a temperature of 80℃ until constant weight.
[0011] Furthermore, the preparation method of the modified graphene oxide is: 0.5 g of graphene oxide was weighed and dispersed in 500 mL of PBS buffer. After ultrasonic treatment for 3 h, it was heated to 90°C in a water bath. Then, 1-2 mL of polyetheramine was added dropwise under stirring. After stirring for 3-4 h, the mixture was allowed to stand for 12 h and centrifuged and washed until the supernatant was neutral. The modified graphene oxide was obtained after drying.
[0012] Furthermore, in the preparation method of modified graphene oxide, the power of ultrasonic treatment is 300W, the stirring speed of the stirring condition is 300-400r / min, the stirring speed of the stirring reaction is 400-500r / min, and the drying method is to dry at a temperature of 68°C to constant weight.
[0013] A method for preparing a carbon fiber / polyimide composite material with self-repairing function, the preparation method comprising: 2-3 parts by weight of modified carbon fiber and 1-2 parts by weight of modified graphene oxide are added to a polyamic acid solution, stirred at a stirring speed of 200-300 r / min for 1-2 hours, and then allowed to stand overnight. After curing treatment, the result is a carbon fiber / polyimide composite material with self-repairing function.
[0014] Furthermore, the curing method is: placing in an oven and curing at temperatures of 70°C, 90°C, 120°C, 150°C, 180°C, 200°C and 220°C for 2 hours each.
[0015] The present invention provides a carbon fiber / polyimide composite material with self-repairing function and a preparation method thereof. Compared with the existing known technology, the present invention has the following beneficial effects: 1. The present invention uses a diamine cystamine (prepared by reacting cystamine dihydrochloride with potassium hydroxide) containing an aliphatic disulfide bond and 4,4'-diaminodiphenyl disulfide as diamine monomers to react with bisphenol A diether dianhydride to generate a polyamic acid solution. Aliphatic disulfide bonds have higher reactivity than aromatic disulfide bonds and can undergo dynamic exchange reactions at lower temperatures, thereby giving the material self-repairing ability. When the material is damaged, the dynamic exchange reaction of the disulfide bonds can promote the migration and rearrangement of molecular chains. This dynamic process at the molecular level enables the material to achieve self-repair at the microscopic level and restore its original mechanical properties and structural integrity. 4,4'-diaminodiphenyl disulfide also contains disulfide bonds and works together with the diamine cystamine to enhance the self-repairing ability. 2. The bisphenol A diether dianhydride in the present invention is used as a dianhydride monomer and is copolymerized with the diamine cystamine and 4,4'-diaminodiphenyl disulfide containing aliphatic disulfide bonds to form a polyimide matrix. Its rigid benzene ring structure complements the flexible dynamic bond of the disulfide bond, while maintaining the mechanical strength of the material, giving the matrix sufficient molecular chain mobility. The dynamic exchange reaction of the disulfide bond needs to be carried out under conditions where the molecular chain can flow. The ether bond flexible chain segment (such as the diether structure) of the bisphenol A diether dianhydride can reduce the glass transition temperature of the matrix, thereby promoting the diffusion and recombination of the molecular chain at room temperature, thereby significantly improving the self-repair efficiency. 3. Before grafting polycarbosilane, the present invention pre-treats the carbon fibers with allyldimethylchlorosilane to introduce active groups, promote the grafting reaction of polycarbosilane, and further improve the interfacial bonding strength. By chemically grafting polycarbosilane on the carbon fiber surface, an organic-inorganic hybrid interface layer can be formed. Polycarbosilane has excellent thermal stability and mechanical properties, and can enhance the interfacial bonding strength between the carbon fibers and the polyimide matrix, thereby improving the overall strength of the composite material. 4. The two-dimensional nanostructure of graphene oxide in the present invention can effectively disperse stress and improve the toughness of the material. At the same time, it acts as a nanofiller to enhance the mechanical properties of the polyimide matrix. Polyetheramine is combined with graphene oxide through chemical bonding, which can improve the dispersion of graphene oxide in the polyimide matrix. Graphene oxide itself has excellent thermal conductivity, which can accelerate the transfer of heat in the material and promote the self-healing reaction. DETAILED DESCRIPTION
[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.
[0017] The present invention will be further described below with reference to the embodiments.
[0018] The sources of some components in the Examples and Comparative Examples are as follows: Cystamine dihydrochloride, Macklin's reagent; Potassium hydroxide, Tianjin Kemeiou Chemical Reagent Co., Ltd.; Dichloromethane, Tianjin Kemeiou Chemical Reagent Co., Ltd.; Anhydrous magnesium sulfate, Tianjin Kemeiou Chemical Reagent Co., Ltd.; 4,4'-Diaminodiphenyl disulfide, Tianjin Zotye Chemical Technology Co., Ltd.; N,N-dimethylacetamide, Tianjin Zotye Chemical Technology Co., Ltd.; Bisphenol A diether dianhydride, Tianjin Zhongtai Chemical Technology Co., Ltd.; Carbon fiber, Taili Carbon Fiber Co., Ltd.; Acetone, Sinopharm Chemical Reagent Co., Ltd.; Allyldimethylsilyl chloride, Shanghai Aladdin Biochemical Technology Co., Ltd.; Polycarbosilane, Fujian Jianya New Materials Co., Ltd.; Toluene, Shanghai Aladdin Biochemical Technology Co., Ltd.; Titanocene dichloride, Wuhan Smike Biotechnology Co., Ltd.; Graphene oxide, Nanjing Xianfeng Nanomaterials; PBS buffer, Shanghai Kehua Bioengineering Co., Ltd.; Polyetheramine, Shanghai Aladdin Biochemical Technology Co., Ltd.
[0019] Example 1: A carbon fiber / polyimide composite material with self-repairing function of this embodiment, the carbon fiber / polyimide composite material with self-repairing function is composed of the following components: polyamic acid solution, modified carbon fiber and modified graphene oxide; The polyamic acid solution is prepared with diamine cystamine containing aliphatic disulfide bonds, 4,4'-diaminodiphenyl disulfide and bisphenol A diether dianhydride as main raw materials; The preparation steps of the diamine cystamine containing aliphatic disulfide bonds are as follows: Step A: 30 g of cystamine dihydrochloride was dissolved in 100 mL of deionized water and stirred at 300 rpm for 10 min. 45 mL of 10 mol / L potassium hydroxide solution was then added dropwise at a rate of 1 drop / s. The mixture was magnetically stirred at 500 rpm for 1 h to obtain the reaction components. Step B: extract the reaction components with dichloromethane. After extraction three times, all organic phases are pooled and dried for 12 hours with excess anhydrous magnesium sulfate. The obtained organic phases are filtered and rotary evaporated to obtain the diamine cystamine containing aliphatic disulfide bonds.
[0020] The preparation steps of polyamic acid solution are: Step 1, weighing 2 g of aliphatic disulfide-containing diamine cystamine, 4 g of 4,4'-diaminodiphenyl disulfide and 50 mL of N,N-dimethylacetamide into a flask, stirring at room temperature at a stirring speed of 500 r / min for 30 min, and recording the mixture as a mixed component; Step 2: 8 g of bisphenol A diether dianhydride was added to the mixed components in half in four portions, and the mixture was mechanically stirred at a stirring speed of 300 r / min for 12 h to obtain a polyamic acid solution.
[0021] The modified carbon fiber is prepared by chemically grafting polycarbosilane on the surface of the carbon fiber. The preparation steps are as follows: Step i: 10 g of carbon fiber was immersed in acetone for 12 h, the filtrate was removed and dried, and then added together with 0.5 g of allyldimethylsilyl chloride to 150 mL of toluene, stirred at a stirring speed of 400 r / min for 30 min, and then placed in a water bath at 40° C. and heated for 24 h. The obtained product was recorded as the reaction component; Step ii, weighing 2 g of polycarbosilane and adding it to 50 mL of toluene, stirring at a stirring speed of 500 r / min for 10 minutes, the result is recorded as the polycarbosilane component; Step iii: Place the reaction components at a temperature of 75°C, add 0.2g of dichlorotitacenes, react for 10 minutes, add the polycarbosilane component, mechanically react for 24 hours, filter out the filtrate and dry it at a temperature of 80°C to constant weight, then place it in a tubular furnace at 450°C under a nitrogen atmosphere for 1 hour to obtain the modified carbon fiber.
[0022] Modified graphene oxide is prepared by modifying graphene oxide with polyetheramine, and its preparation method is as follows: 0.5 g of graphene oxide was weighed and dispersed in 500 mL of PBS buffer, ultrasonically treated at a power of 300 W for 3 h, and then heated in a water bath to 90°C. Subsequently, 1 mL of polyetheramine was added dropwise at a stirring speed of 300 r / min. The mixture was stirred at a stirring speed of 400 r / min for 3 h, then allowed to stand for 12 h and centrifuged until the supernatant was neutral. The modified graphene oxide was obtained by drying at a temperature of 68°C to constant weight.
[0023] A method for preparing a carbon fiber / polyimide composite material with self-repairing function, the preparation method comprising: 2 parts by weight of modified carbon fiber and 1 part by weight of modified graphene oxide were added to a polyamic acid solution, stirred at a stirring speed of 200 r / min for 1 hour, and then allowed to stand overnight. After curing treatment, the obtained carbon fiber / polyimide composite material with self-repairing function was obtained, wherein the curing treatment method was: placed in an oven and cured at temperatures of 70°C, 90°C, 120°C, 150°C, 180°C, 200°C and 220°C for 2 hours each.
[0024] Example 2: A carbon fiber / polyimide composite material with self-repairing function of this embodiment, the carbon fiber / polyimide composite material with self-repairing function is composed of the following components: polyamic acid solution, modified carbon fiber and modified graphene oxide; The polyamic acid solution is prepared with diamine cystamine containing aliphatic disulfide bonds, 4,4'-diaminodiphenyl disulfide and bisphenol A diether dianhydride as main raw materials; The preparation steps of the diamine cystamine containing aliphatic disulfide bonds are as follows: Step A: 32 g of cystamine dihydrochloride was dissolved in 100 mL of deionized water and stirred at 400 rpm for 10 min. 48 mL of 10 mol / L potassium hydroxide solution was then added dropwise at a rate of 1 drop / s and magnetically stirred at 600 rpm for 1 h to obtain the reaction components. Step B: extract the reaction components with dichloromethane. After extraction three times, all organic phases are pooled and dried for 12 hours with excess anhydrous magnesium sulfate. The obtained organic phases are filtered and rotary evaporated to obtain the diamine cystamine containing aliphatic disulfide bonds.
[0025] The preparation steps of polyamic acid solution are: Step 1, weighing 3 g of aliphatic disulfide-containing diamine cystamine, 5 g of 4,4'-diaminodiphenyl disulfide and 50 mL of N,N-dimethylacetamide into a flask, stirring at room temperature at a stirring speed of 600 r / min for 30 min, and recording the mixture as a mixed component; Step 2: Add 9 g of bisphenol A diether dianhydride into the mixed components in half in 5 portions, and mechanically stir at a stirring speed of 400 r / min for 12 hours to obtain a polyamic acid solution.
[0026] The modified carbon fiber is prepared by chemically grafting polycarbosilane on the surface of the carbon fiber. The preparation steps are as follows: Step i: immerse 12 g of carbon fiber in acetone for 12 h, remove the filtrate, dry it, and add it together with 0.8 g of allyldimethylsilyl chloride to 150 mL of toluene. Stir at a stirring speed of 500 r / min for 30 min, and then heat it in a water bath at 40°C for 24 h. The result is recorded as the reaction component; Step ii, weighing 3 g of polycarbosilane and adding it to 50 mL of toluene, stirring at a stirring speed of 600 r / min for 10 min, the result is recorded as the polycarbosilane component; Step iii: Place the reaction components at a temperature of 75°C, add 0.3g of dichlorotitacenes, react for 10 minutes, add the polycarbosilane component, mechanically react for 24 hours, filter out the filtrate and dry it at a temperature of 80°C to constant weight, then place it in a tubular furnace at 450°C under a nitrogen atmosphere for 1 hour to obtain the modified carbon fiber.
[0027] Modified graphene oxide is prepared by modifying graphene oxide with polyetheramine, and its preparation method is as follows: Take 0.5g graphene oxide dispersed in 500mL PBS buffer, ultrasonic treatment for 3h with 300W power, then water bath heating to 90℃, followed by adding 2mL polyether amine with stirring speed of 400r / min, stirring for 4h with stirring speed of 500r / min, then standing for 12h and centrifugal washing until the supernatant is neutral, drying at 68℃ until constant weight, then the modified graphene oxide is obtained.
[0028] A preparation method of a carbon fiber / polyimide composite material with self-repairing function, the preparation method comprises the following steps: 3 parts by weight of modified carbon fiber and 2 parts by weight of modified graphene oxide are added into a polyamic acid solution, stirring for 2h with stirring speed of 300r / min, then standing overnight, and the carbon fiber / polyimide composite material with self-repairing function is obtained after curing treatment, wherein the curing treatment method is as follows: placing in an oven, and curing at 70℃, 90℃, 120℃, 150℃, 180℃, 200℃ and 220℃ for 2h respectively. Embodiment
[0029] The carbon fiber / polyimide composite material with self-repairing function comprises a polyamic acid solution, modified carbon fiber and modified graphene oxide. The polyamic acid solution is prepared by taking diamine cystamine containing aliphatic disulfide bond, 4,4'-diamino diphenyl disulfide and bisphenol A type diether dianhydride as main raw materials; The preparation steps of the diamine cystamine containing aliphatic disulfide bond are as follows: Step A, take 31g cystamine dihydrochloride and dissolve in 100mL deionized water, stirring for 10min with stirring speed of 400r / min, then adding 46mL potassium hydroxide solution with concentration of 10mol / L at a drop rate of 1 drop / s, and stirring for 1h with magnetic stirring speed of 600r / min, then the reaction component is obtained; Step B, extracting the reaction component with dichloromethane, collecting all the organic phases after extracting for 3 times, adding excess anhydrous magnesium sulfate and drying for 12h, filtering and rotary evaporation, then the diamine cystamine containing aliphatic disulfide bond is obtained.
[0030] The preparation steps of the polyamic acid solution are as follows: Step 1, taking 3g diamine cystamine containing aliphatic disulfide bond, 4g 4,4'-diamino diphenyl disulfide and 50mL N,N-dimethylacetamide into a flask, stirring for 30min at room temperature with stirring speed of 600r / min, and marking as mixed component; Step 2: Add 9 g of bisphenol A diether dianhydride into the mixed components in half four times, and stir mechanically at a stirring speed of 400 r / min for 12 hours to obtain a polyamic acid solution.
[0031] The modified carbon fiber is prepared by chemically grafting polycarbosilane on the surface of the carbon fiber. The preparation steps are as follows: Step i: 11 g of carbon fiber was immersed in acetone for 12 h, the filtrate was removed and dried, and then added together with 0.7 g of allyldimethylsilyl chloride to 150 mL of toluene, stirred at a stirring speed of 500 r / min for 30 min, and then placed in a water bath at 40° C. and heated for 24 h. The obtained product was recorded as the reaction component; Step ii, weighing 3 g of polycarbosilane and adding it to 50 mL of toluene, stirring at a stirring speed of 600 r / min for 10 minutes, and recording the result as the polycarbosilane component; Step iii: Place the reaction components at a temperature of 75°C, add 0.2g of dichlorotitacenes, react for 10 minutes, add the polycarbosilane component, mechanically react for 24 hours, filter out the filtrate and dry it at a temperature of 80°C to constant weight, then place it in a tubular furnace at 450°C under a nitrogen atmosphere for 1 hour to obtain the modified carbon fiber.
[0032] Modified graphene oxide is prepared by modifying graphene oxide with polyetheramine, and its preparation method is as follows: 0.5 g of graphene oxide was weighed and dispersed in 500 mL of PBS buffer, ultrasonically treated at a power of 300 W for 3 h, and then heated in a water bath to 90°C. Subsequently, 2 mL of polyetheramine was added dropwise at a stirring speed of 400 r / min. The mixture was stirred at a stirring speed of 500 r / min for 4 h, then allowed to stand for 12 h and centrifuged until the supernatant was neutral. The modified graphene oxide was obtained by drying at a temperature of 68°C to constant weight.
[0033] A method for preparing a carbon fiber / polyimide composite material with self-repairing function, the preparation method comprising: 2 parts by weight of modified carbon fiber and 2 parts by weight of modified graphene oxide were added to a polyamic acid solution, stirred at a stirring speed of 300 r / min for 2 hours, and then allowed to stand overnight. After curing, the result was a carbon fiber / polyimide composite material with self-repairing function. The curing method was as follows: placing it in an oven and curing it at temperatures of 70°C, 90°C, 120°C, 150°C, 180°C, 200°C and 220°C for 2 hours each.
[0034] Comparative Example 1 The carbon fiber / polyimide composite material with self-repairing function and its preparation method provided in this comparative example are roughly the same as those in Example 1, with the main difference being that the modified carbon fiber in Example 1 is replaced with unmodified carbon fiber in this comparative example.
[0035] Comparative Example 2 The carbon fiber / polyimide composite material with self-repairing function and the preparation method thereof provided in this comparative example are roughly the same as those in Example 1, with the main difference being that the modified graphene oxide in Example 1 is replaced with unmodified graphene oxide in this comparative example.
[0036] Performance Testing The carbon fiber / polyimide composite materials with self-repairing function prepared in Examples 1-3 and Comparative Examples 1-2 are marked as Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2, respectively. The performance of Examples 1-3 and Comparative Examples 1-2 was then tested. The specific testing methods and test items are as follows: 1. The tensile strength of Examples 1-3 and Comparative Examples 1-2 was tested with reference to the standard of GB / T1040.1-2018, and the obtained data were recorded in the following table; 2. The tensile strength of Examples 1-3 and Comparative Examples 1-2 after standing in an oven at 200° C. for 3 hours was tested with reference to the standard of GB / T1040.1-2018, and the obtained data are recorded in the following table; 3. The tensile strength of Examples 1-3 and Comparative Examples 1-2 after standing in an oven at 260° C. for 3 hours and cooling to room temperature was tested with reference to the standard of GB / T1040.1-2018. The obtained data are recorded in the table below. .
[0037] It can be seen from the data in the above table that the mechanical properties of the carbon fiber / polyimide composite materials with self-repairing function prepared in Examples 1-3 are significantly better than those of Comparative Examples 1-2, and the mechanical properties after self-repair are still better than those of Comparative Examples 1-2, indicating that adding modified carbon fiber and graphene oxide in the preparation of carbon fiber / polyimide composite materials with self-repairing function can improve the mechanical properties.
[0038] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.
[0039] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.
Claims
1. A carbon fiber / polyimide composite material with self-repairing function, characterized in that: The carbon fiber / polyimide composite material with self-repairing function is composed of the following components: polyamic acid solution, modified carbon fiber and modified graphene oxide; The polyamic acid solution is prepared with diamine cystamine containing aliphatic disulfide bonds, 4,4'-diaminodiphenyl disulfide and bisphenol A diether dianhydride as main raw materials; The modified carbon fiber is prepared by chemically grafting polycarbosilane onto the surface of the carbon fiber; The modified graphene oxide is prepared by modifying graphene oxide with polyetheramine.
2. The carbon fiber / polyimide composite material with self-repairing function according to claim 1, characterized in that: The preparation steps of the diamine cystamine containing aliphatic disulfide bonds are: Step A: Weigh 30-32 g of cystamine dihydrochloride and dissolve it in 100 mL of deionized water. Stir the mixture at a stirring speed of 300-400 r / min for 10 min. Then, add 45-48 mL of 10 mol / L potassium hydroxide solution at a dropping rate of 1 drop / s. Stir the mixture magnetically at a stirring speed of 500-600 r / min for 1 h. The resulting mixture is the reaction component. Step B: extract the reaction components with dichloromethane. After extraction three times, all organic phases are pooled and dried for 12 hours with excess anhydrous magnesium sulfate. The obtained organic phases are filtered and rotary evaporated to obtain the diamine cystamine containing aliphatic disulfide bonds.
3. The carbon fiber / polyimide composite material with self-repairing function according to claim 1, characterized in that: The preparation steps of the polyamic acid solution are: Step 1, weighing 2-3 g of aliphatic disulfide-containing diamine cystamine, 4-5 g of 4,4'-diaminodiphenyl disulfide and 50 mL of N,N-dimethylacetamide into a flask, mixing and stirring, and recording as a mixed component; Step 2: Add 8-9 g of bisphenol A diether dianhydride into the mixed components in half in 4-5 portions, and mechanically stir for 12 hours to obtain a polyamic acid solution.
4. The carbon fiber / polyimide composite material with self-repairing function according to claim 3, characterized in that: The mixing and stirring method in step 1 is to stir at a stirring speed of 500-600 r / min for 30 minutes at room temperature, and the stirring speed of the mechanical stirring in step 2 is 300-400 r / min.
5. The carbon fiber / polyimide composite material with self-repairing function according to claim 1, characterized in that: The preparation steps of the modified carbon fiber are: Step i, immerse 10-12 g of carbon fiber in acetone for 12 h, remove the filtrate and dry it, then add it together with 0.5-0.8 g of allyldimethylsilyl chloride into 150 mL of toluene, stir to dissolve, and heat in a 40°C water bath for 24 h. The result is recorded as the reaction component; Step ii, weighing 2-3 g of polycarbosilane and adding it into 50 mL of toluene, and dispersing the mixture evenly, the resultant mixture is recorded as the polycarbosilane component; Step iii: Place the reaction components at a temperature of 75°C, add 0.2-0.3g of dichlorotitacenes, react for 10 minutes, add the polycarbosilane component, mechanically react for 24 hours, filter and remove the filtrate, and dry it. Then place it in a tubular furnace at 450°C under a nitrogen atmosphere for 1 hour to obtain the modified carbon fiber.
6. The carbon fiber / polyimide composite material with self-repairing function according to claim 5, characterized in that: The stirring and dissolving method in step i is stirring at a stirring speed of 400-500 r / min for 30 minutes, the uniform dispersion method in step ii is stirring at a stirring speed of 500-600 r / min for 10 minutes, and the drying method in step iii is drying at a temperature of 80°C to constant weight.
7. The carbon fiber / polyimide composite material with self-repairing function according to claim 1, characterized in that: The preparation method of the modified graphene oxide is: 0.5 g of graphene oxide was weighed and dispersed in 500 mL of PBS buffer. After ultrasonic treatment for 3 h, it was heated to 90°C in a water bath. Then, 1-2 mL of polyetheramine was added dropwise under stirring. After stirring for 3-4 h, the mixture was allowed to stand for 12 h and centrifuged and washed until the supernatant was neutral. The modified graphene oxide was obtained after drying.
8. The carbon fiber / polyimide composite material with self-repairing function according to claim 7, characterized in that: In the preparation method of modified graphene oxide, the power of ultrasonic treatment is 300W, the stirring speed of the stirring condition is 300-400r / min, the stirring speed of the stirring reaction is 400-500r / min, and the drying method is to dry at a temperature of 68°C to constant weight.
9. The method for preparing a carbon fiber / polyimide composite material with self-repairing function according to any one of claims 1 to 8, characterized in that: The preparation method is: 2-3 parts by weight of modified carbon fiber and 1-2 parts by weight of modified graphene oxide are added to a polyamic acid solution, stirred at a stirring speed of 200-300 r / min for 1-2 hours, and then allowed to stand overnight. After curing treatment, the result is a carbon fiber / polyimide composite material with self-repairing function.
10. The method for preparing a carbon fiber / polyimide composite material with self-repairing function according to claim 9, characterized in that: The method of the curing treatment is: Place in an oven and cure at 70°C, 90°C, 120°C, 150°C, 180°C, 200°C and 220°C for 2 hours each.