Composite prepreg for forming non-autoclave of liquid oxygen storage tank and preparation method of prepreg

Abstract

The invention belongs to the technical field of composite materials, and particularly relates to a prepreg for forming a non-autoclave of a composite material liquid oxygen storage box and a preparation method of the prepreg. The resin matrix is composed of base resin and a compound component, and the viscosity of the compound component is consistent with that of the base resin; the preparation method comprises the following steps: firstly preparing basic resin and a compound component, then blending the basic resin and the compound component to obtain a prepreg resin matrix, and finally obtaining the prepreg for forming the non-autoclave through coating and fiber fabric impregnation processes. The composite material prepared from the prepreg has the same mechanical property as a traditional autoclave molding composite material, the manufacturing cost is low, meanwhile, the resin matrix and the composite material under the process have good liquid oxygen compatibility, and the manufacturing cost of the spacecraft composite material liquid oxygen storage tank can be remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, in particular to a prepreg for non-autoclave molding of a composite material liquid oxygen tank and a preparation method thereof. Background Art

[0002] As an important part of the propulsion system of a space vehicle, the liquid oxygen tank is one of the components with the largest volume and weight of the launch vehicle. It has become a consensus in the world's aerospace industry to use composite materials with high specific strength and modulus, fatigue resistance, corrosion resistance, good designability and integrated molding to manufacture spacecraft liquid oxygen tanks, reduce the weight of space vehicles and improve the carrying efficiency. At present, composite liquid oxygen tanks (diameter 5~12m) are mainly formed by autoclave molding process, but the molding equipment of this molding method is expensive, energy consumption is high, the molding cycle is long, and the size of the structure is limited by the size of the autoclave. With the formulation and implementation of plans such as Mars exploration, manned lunar landing, and commercial spaceflight, the size of rocket tanks will be further increased, and the corresponding manufacturing cost of composite tanks based on autoclave molding process will also increase significantly.

[0003] In view of the cost problem faced by the autoclave prepreg molding process for large-size composite tanks, the ideal solution is to adopt a non-autoclave molding process. In the non-autoclave molding process of composite materials, the resin in the prepreg is infiltrated with the fiber under vacuum negative pressure, and the air or other volatiles contained in the resin / fiber are discharged through vacuum negative pressure to compact the composite material. Therefore, the key to preparing a composite material with consistent autoclave molding performance at one atmosphere is to develop a resin system that is suitable for paving at room temperature, has good fluidity at high temperature and moderate reactivity. In addition, liquid oxygen is an important low-temperature oxidant in the propulsion system of spacecraft, and has the dual properties of low temperature and strong oxidizing properties. Therefore, in addition to meeting the requirements of low-temperature mechanical properties, the non-autoclave molding prepreg used for the molding of composite liquid oxygen tanks also needs to ensure that the corresponding composite material is chemically compatible with liquid oxygen. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the main purpose of the present invention is to provide a prepreg for non-autoclave molding of a composite material liquid oxygen tank and a preparation method thereof.

[0005] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0006] A prepreg for non-autoclave molding of a composite material liquid oxygen tank, comprising a resin matrix and reinforcing fibers; the resin matrix comprises a base resin and a compound component, the compound component has the same viscosity as the base resin; the base resin comprises an epoxy resin, a curing agent, a toughening agent, and a viscosity regulator, the compound component comprises a modifier, a viscosity regulator, and a toughening agent; the mass of the resin matrix accounts for 30-70wt% of the mass of the prepreg.

[0007] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, in which: in the base resin, the mass of the epoxy resin is 50-80wt% of the total mass of the base resin, the weight of the curing agent is 5-20wt% of the weight of the epoxy resin, the weight of the toughening agent is 1-30wt% of the weight of the epoxy resin, and the weight of the viscosity regulator is 2-20wt% of the weight of the base resin.

[0008] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, the viscosity of the base resin at room temperature is 300-1500 Pa·S; the viscosity at 70-80°C is 8-20 Pa·S, and the gel time is 100-500 min; the viscosity at 120-130°C is 0.5-5 Pa·S, and the gel time is 30-100 min.

[0009] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, in which: in the compound components, the mass of the modifier accounts for 20-50wt% of the total mass of the compound components, the mass of the viscosity regulator accounts for 20-60wt% of the total weight of the compound components, and the mass of the toughening agent accounts for 1-15wt% of the total mass of the compound components.

[0010] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, the reinforcing fibers include glass fibers, carbon fibers, and basalt fibers.

[0011] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, the epoxy resin includes one or more of bisphenol A solid epoxy resin, bisphenol A liquid epoxy resin, tetrafunctional glycidylamine epoxy resin, phenolic epoxy resin, and bisphenol S epoxy resin.

[0012] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, the curing agent includes one or more of diaminodiphenyl sulfone, dicyandiamide, urea accelerator, imidazole, diaminoimidazole triazine complex, and boron trifluoride monoethylamine.

[0013] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, the toughening agent includes one or more of polyether sulfone, polyether ether ketone, hyperbranched polymer, nitrile rubber, and silicone rubber.

[0014] As a preferred embodiment of the composite material prepreg for non-autoclave molding of liquid oxygen tanks described in the present invention, the modifier includes one or more of triphenylphosphine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, hexachlorocyclotriphosphazene, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide, polyphosphazene, and tetrabromobisphenol A.

[0015] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, the viscosity regulator includes one or more of phenyl glycidyl ether, polypropylene glycol diglycidyl ether, tricresyl phosphate, triethyl phosphate, liquid polybutadiene rubber, liquid silane, and polyurethane.

[0016] As a preferred embodiment of the prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, the viscosity of the resin matrix at room temperature is 300-1500 Pa·S; the viscosity at 70-80°C is 8-20 Pa·S, and the gel time is 100-500 min; the viscosity at 120-130°C is 0.5-5 Pa·S, and the gel time is 30-100 min.

[0017] To solve the above technical problem, according to another aspect of the present invention, the present invention provides the following technical solution:

[0018] A method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank comprises the following steps:

[0019] S1, mixing epoxy resin, curing agent, toughening agent and viscosity regulator to obtain a base resin;

[0020] S2, blending the modifier, viscosity regulator and toughening agent to obtain a compound component, ensuring that the viscosity of the compound component is consistent with that of the base resin;

[0021] S3, blending the base resin and the compounding components to obtain a prepreg resin matrix;

[0022] S4. Prepreg for non-autoclave molding of composite liquid oxygen tank is obtained through coating and reinforcing fiber impregnation process.

[0023] As a preferred embodiment of the method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank described in the present invention, wherein: in the step S2, the modifier, viscosity regulator, and toughening agent are blended at 80-150° C., and the ratio of the modifier, toughening agent, and viscosity regulator is adjusted to ensure that the viscosity of the composite component is consistent with the base resin.

[0024] As a preferred embodiment of the method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to the present invention, in step S4, the temperature is adjusted to 70-80°C so that the viscosity of the resin matrix is ​​8-20 Pa·S, and a coating process is adopted, by adjusting the coating speed to 0.5-5 m / min and the gap between the rubber rollers to 0.01-0.2 mm to control the surface density of the rubber film.

[0025] As a preferred embodiment of the method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to the present invention, in step S4, the adhesive film is impregnated on the reinforcing fiber fabric, the impregnation temperature is controlled to be 70-80°C, the viscosity of the resin matrix is ​​made to be 8-20 Pa·S, and the prepreg for non-autoclave molding of a composite material liquid oxygen tank is obtained by adjusting the impregnation speed and the gap between the pressure rollers.

[0026] As a preferred embodiment of the method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to the present invention, in the step S4, the impregnation speed is adjusted to 2-3 m / min, and the gap between the pressure rollers is adjusted to 0.2-0.5 mm, so as to obtain a prepreg with an impregnation degree of 70-80%, and the prepreg is suitable for non-autoclave molding of a composite material liquid oxygen tank with a thickness of 2-3 mm.

[0027] As a preferred embodiment of the method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to the present invention, in the step S4, the impregnation speed is adjusted to 0.5-2 m / min, and the gap between the pressure rollers is 0.05-0.2 mm, so as to obtain a prepreg with an impregnation degree of 80-90%, and the prepreg is suitable for non-autoclave molding of a composite material liquid oxygen tank with a thickness of 0.5-2 mm.

[0028] The beneficial effects of the present invention are as follows:

[0029] The present invention provides a prepreg for non-autoclave molding of a composite liquid oxygen tank and a preparation method thereof, wherein the prepreg is composed of a resin matrix and reinforcing fibers; the resin matrix is ​​composed of a base resin and a compound component, and the compound component has the same viscosity as the base resin; firstly, the base resin and the compound component are prepared, and then the base resin and the compound component are blended to obtain a prepreg resin matrix, and finally, the prepreg for non-autoclave molding is obtained by coating and impregnation with fiber fabrics. The composite material prepared by the prepreg of the present invention has comparable mechanical properties to traditional autoclave molding composite materials, and has low manufacturing cost. At the same time, the resin matrix and the composite material under this process have good liquid oxygen compatibility, which can significantly reduce the manufacturing cost of composite liquid oxygen tanks for spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1 This is the liquid oxygen compatibility test result of the resin matrix of Example 1 of the present invention.

[0032] Figure 2 The performance comparison results of the composite material prepared by the prepreg of Example 1 of the present invention and the composite material formed by the traditional autoclave are shown.

[0033] Figure 3 This is the liquid oxygen compatibility test result of the composite material prepared from the prepreg of Example 1 of the present invention.

[0034] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The present invention provides a prepreg for non-autoclave molding of a composite material liquid oxygen tank and a preparation method thereof, which meets the requirements of a spacecraft liquid oxygen tank for low temperature resistance and liquid oxygen compatibility of the composite material and significantly reduces the cost.

[0037] According to one aspect of the present invention, the present invention provides the following technical solution:

[0038] A prepreg for non-autoclave molding of a composite material liquid oxygen tank, comprising a resin matrix and reinforcing fibers; the resin matrix comprises a base resin and a compound component, the compound component has the same viscosity as the base resin; the base resin comprises an epoxy resin, a curing agent, a toughening agent, and a viscosity regulator, the compound component comprises a modifier, a viscosity regulator, and a toughening agent; the mass of the resin matrix accounts for 30-70wt% of the mass of the prepreg.

[0039] Preferably, in the base resin, the weight of the epoxy resin is 50-80wt% of the total weight of the base resin, the weight of the curing agent is 5-20wt% of the weight of the epoxy resin, the weight of the toughening agent is 1-30wt% of the weight of the epoxy resin, and the weight of the viscosity regulator is 2-20wt% of the weight of the base resin.

[0040] Preferably, the viscosity of the base resin at room temperature is 300-1500 Pa·S; the viscosity at 70-80°C is 8-20 Pa·S, and the gel time is 100-500 min; the viscosity at 120-130°C is 0.5-5 Pa·S, and the gel time is 30-100 min.

[0041] Preferably, in the composite components, the mass of the modifier accounts for 20-50wt% of the total mass of the composite components, the mass of the viscosity regulator accounts for 20-60wt% of the total weight of the composite components, and the mass of the toughening agent accounts for 1-15wt% of the total mass of the composite components.

[0042] Preferably, the reinforcing fibers include glass fibers, carbon fibers, and basalt fibers.

[0043] Preferably, the epoxy resin includes one or more of bisphenol A type solid epoxy resin, bisphenol A type liquid epoxy resin, tetrafunctional glycidylamine type epoxy resin, novolac epoxy resin, and bisphenol S epoxy resin.

[0044] Preferably, the curing agent includes one or more of diaminodiphenyl sulfone, dicyandiamide, urea accelerator, imidazole, diaminoimidazole triazine complex, and boron trifluoride monoethylamine.

[0045] Preferably, the toughening agent includes one or more of polyethersulfone, polyetheretherketone, hyperbranched polymer, nitrile rubber, liquid polybutadiene rubber, and silicone rubber.

[0046] Preferably, the modifier includes one or more of triphenylphosphine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, hexachlorocyclotriphosphazene, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide, polyphosphazene, and tetrabromobisphenol A.

[0047] Preferably, the viscosity regulator includes one or more of phenyl glycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, tricresyl phosphate, triethyl phosphate, liquid silane, and polyurethane.

[0048] Preferably, the viscosity of the resin matrix at room temperature is 300-1500 Pa·S; at 70-80°C, the viscosity is 8-20 Pa·S, and the gel time is 100-500 min; at 120-130°C, the viscosity is 0.5-5 Pa·S, and the gel time is 30-100 min.

[0049] According to another aspect of the present invention, the present invention provides the following technical solution:

[0050] A method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank comprises the following steps:

[0051] S1, mixing epoxy resin, curing agent, toughening agent and viscosity regulator to obtain a base resin;

[0052] S2, blending the modifier, viscosity regulator and toughening agent to obtain a compound component, ensuring that the viscosity of the compound component is consistent with that of the base resin;

[0053] S3, blending the base resin and the compounding components to obtain a prepreg resin matrix;

[0054] S4. Prepreg for non-autoclave molding of composite liquid oxygen tank is obtained through coating and reinforcing fiber impregnation process.

[0055] Firstly, base resins and compounding components with the same viscosity but different functions are prepared. The viscosity, gel time and liquid oxygen compatibility of the resin matrix are regulated by adjusting the ratio of the base resin. After coating, a film that meets the requirements for non-autoclave prepreg molding is obtained. Furthermore, according to the thickness (0.5-3mm) of non-autoclave molding of liquid oxygen tanks of different composite materials, the impregnation process of the film and reinforced fiber fabric is improved to prepare prepregs with a film impregnation degree of 70-90% for the fiber. During the molding of the composite material, the unimpregnated fibers play a role in air conduction, which is beneficial for the resin to further penetrate the fibers and reduce the molding defects of the composite material.

[0056] Preferably, in step S2, the modifier, viscosity regulator and toughening agent are blended at 80-150° C., and the ratio of the modifier, toughening agent and viscosity regulator is adjusted to ensure that the viscosity of the composite component is consistent with the base resin.

[0057] Preferably, in step S4, the temperature is adjusted to 70-80° C. so that the viscosity of the resin matrix is ​​8-20 Pa·S, and the coating process is adopted to control the surface density of the film by adjusting the coating speed to 0.5-5 m / min and the gap between the rubber rollers to 0.01-0.2 mm.

[0058] Preferably, in step S4, the adhesive film is impregnated on the reinforcing fiber fabric, the impregnation temperature is controlled to be 70-80° C., the viscosity of the resin matrix is ​​made to be 8-20 Pa·S, and the prepreg for non-autoclave molding of the composite material liquid oxygen tank is obtained by adjusting the impregnation speed and the gap between the pressure rollers.

[0059] Preferably, in step S4, the impregnation speed is adjusted to 2-3 m / min, and the gap between the pressure rollers is 0.2-0.5 mm, so as to obtain a prepreg with an impregnation degree of 70-80%, which is suitable for non-autoclave molding of a composite material liquid oxygen tank with a thickness of 2-3 mm.

[0060] Preferably, in step S4, the impregnation speed is adjusted to 0.5-2 m / min, and the gap between the pressure rollers is 0.05-0.2 mm, so as to obtain a prepreg with an impregnation degree of 80-90%, which is suitable for non-autoclave molding of a composite material liquid oxygen tank with a thickness of 0.5-2 mm.

[0061] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0062] Example 1

[0063] A method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank comprises the following steps:

[0064] S1, take 2kg of bisphenol A solid epoxy resin with an epoxy equivalent of 480-500g / mol, 1kg of bisphenol A liquid epoxy resin with an epoxy equivalent of 800-833g / mol, 2kg of tetrafunctional glycidylamine epoxy resin with an epoxy equivalent of 120-133g / mol, and 2kg of phenolic epoxy resin with an epoxy equivalent of 180-208g / mol, heat and stir in a 130°C reactor to mix evenly; add 0.4kg of polyethersulfone, 0.6kg of hyperbranched resin H30, and 0.5kg of triethyl phosphate to the above resin system, heat and stir at 130°C until the resin is completely dissolved, then lower the reactor temperature to 80°C, add 0.6kg of dicyandiamide and 0.12kg of urea accelerator, stir evenly, and lower the temperature to 50°C to obtain a base resin; the viscosity of the base resin at 80°C is 15Pa·S;

[0065] S2, take 0.4 kg of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 0.2 kg of triphenylphosphine, 0.4 kg of phenyl glycidyl ether, 0.5 kg of tricresyl phosphate, 0.1 kg of polyurethane (molecular weight: 15000 g / mol), 0.2 kg of liquid polybutadiene rubber (molecular weight: 4000 g / mol), condense and reflux at 180°C, stir for 2 hours to obtain a clear and transparent solution, cool to 50°C, and obtain a composite component; the viscosity of the composite component at 80°C is 15 Pa·S;

[0066] S3. Mix the base resin and compound components evenly in a three-roll mill at a mixing temperature of 60°C, a three-roll mill speed of 5r / min, and a roller spacing of 0.2mm to obtain a resin matrix. The resin matrix is ​​heated and cured, and the liquid oxygen compatibility is tested. There is no obvious phenomenon after 20 impacts, and the liquid oxygen compatibility test is passed (the liquid oxygen compatibility test results of the resin matrix are as follows Figure 1 shown);

[0067] S4, adjust the temperature to 80℃, make the viscosity of the resin matrix at 15Pa·S, adopt the coating process, adjust the coating speed at 1m / min, and the gap between the rubber rollers at 0.03mm, and obtain a surface density of 50g / m 2 The film is impregnated on the 3K fabric made of unidirectional carbon fiber (T300 grade carbon fiber, fabric surface density is 85g / m 2 ), by controlling the impregnation temperature at 80°C, the resin matrix viscosity at 15Pa·S, adjusting the impregnation speed at 2m / min, and the roller gap at 0.15mm, a prepreg with an impregnation degree of 85% and a resin content of 40% was obtained.

[0068] The performance comparison results of the composite material prepared by non-autoclave prepreg in this embodiment and the composite material prepared by traditional autoclave are as follows: Figure 2 As shown, both curing processes are 130℃ / 3h. Figure 2 It can be seen that the performance of the composite material prepared by the non-autoclave prepreg molding process in this embodiment is basically consistent with the performance of the composite material obtained by the traditional autoclave process. Figure 3 is the liquid oxygen compatibility test result of the composite material prepared by the prepreg of this embodiment. Figure 3 It can be seen that the composite material has good compatibility with liquid oxygen.

[0069] Example 2

[0070] A method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank comprises the following steps:

[0071] S1, take 3kg of bisphenol A solid epoxy resin with epoxy equivalent of 480-500g / mol, 2kg of bisphenol A liquid epoxy resin with epoxy equivalent of 800-833g / mol, 2kg of tetrafunctional glycidylamine epoxy resin with epoxy equivalent of 120-133g / mol, 1kg of phenolic epoxy resin with epoxy equivalent of 180-208g / mol, heat in a reactor at 140°C, stir and mix evenly; add to the above resin system 0.6 kg of polyetheretherketone, 0.5 kg of liquid polybutadiene rubber (molecular weight: 4000 g / mol), and 0.6 kg of phenyl glycidyl ether were heated and stirred at 140 ° C until the resin was completely dissolved, then the temperature of the reactor was lowered to 80 ° C, 0.5 kg of dicyandiamide, 0.1 kg of diaminodiphenyl sulfone, and 0.2 kg of urea accelerator were added, stirred evenly, and the temperature was lowered to 50 ° C to obtain a base resin; the viscosity of the base resin at 70 ° C was 15 Pa·S;

[0072] S2, take 1kg of 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide, 0.5kg of polyphosphazene, 1kg of diethylene glycol diglycidyl ether, 0.8kg of tricresyl phosphate, 0.2kg of polyetheretherketone (molecular weight 30000g / mol), stir at 180℃ for 2h to obtain a clear and transparent solution, cool to 50℃ to obtain a composite component; the viscosity of the composite component at 70℃ is 15Pa·S;

[0073] S3. Mix the base resin and compound components evenly in a three-roll mill at a mixing temperature of 50°C, a three-roll mill speed of 8r / min, and a roller spacing of 0.2mm to obtain a resin matrix. The resin matrix is ​​heated and cured, and the liquid oxygen compatibility is tested. There is no obvious phenomenon after 20 impacts, and the liquid oxygen compatibility test is passed;

[0074] S4, adjust the temperature to 70℃, make the viscosity of the resin matrix at 15Pa·S, adopt the coating process, adjust the coating speed at 4m / min, and the gap between the rubber rollers at 0.15mm, and obtain a surface density of 180g / m 2 The film is impregnated with 3K twill carbon fiber fabric (T300 grade carbon fiber, fabric surface density is 200g / m 2 ), by controlling the impregnation temperature at 70°C, the resin matrix viscosity at 15Pa·S, adjusting the impregnation speed at 3m / min, and the roller gap at 0.35mm, a prepreg with an impregnation degree of 70% and a base resin content of 50% was obtained.

[0075] The prepreg of the present invention is composed of a resin matrix and reinforcing fibers; the resin matrix is ​​composed of a base resin and a compound component, and the compound component has the same viscosity as the base resin; firstly, the base resin and the compound component are prepared, and then the base resin and the compound component are blended to obtain a prepreg resin matrix, and finally a prepreg for non-autoclave molding is obtained by coating and impregnation with fiber fabrics. The composite material prepared by the prepreg of the present invention has equivalent mechanical properties to the traditional autoclave molding composite material, and has a low manufacturing cost. At the same time, the resin matrix and the composite material under this process have good liquid oxygen compatibility, which can significantly reduce the manufacturing cost of the composite liquid oxygen tank of the spacecraft.

[0076] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A composite material prepreg for non-autoclave molding of liquid oxygen tank, characterized in that: It is composed of a resin matrix and reinforcing fibers; the resin matrix is ​​composed of a base resin and a compound component, and the viscosity of the compound component is consistent with that of the base resin; the base resin includes an epoxy resin, a curing agent, a toughening agent, and a viscosity regulator, and the compound component includes a modifier, a viscosity regulator, and a toughening agent; the mass of the resin matrix accounts for 30-70wt% of the mass of the prepreg; In the base resin, the weight of the epoxy resin is 50-80wt% of the total weight of the base resin, the weight of the curing agent is 5-20wt% of the weight of the epoxy resin, the weight of the toughening agent is 1-30wt% of the weight of the epoxy resin, and the weight of the viscosity regulator is 2-20wt% of the weight of the base resin; In the compound components, the mass of the modifier accounts for 20-50wt% of the total mass of the compound components, the mass of the viscosity regulator accounts for 20-60wt% of the total weight of the compound components, and the mass of the toughening agent accounts for 1-15wt% of the total mass of the compound components.

2. The prepreg for non-autoclave molding of composite liquid oxygen tank according to claim 1, characterized in that: The viscosity of the base resin at room temperature is 300~1500Pa·S; at 70~80℃, the viscosity is 8~20Pa·S, and the gel time is 100~500min; at 120~130℃, the viscosity is 0.5~5Pa·S, and the gel time is 30~100min.

3. The prepreg for non-autoclave molding of composite liquid oxygen tank according to claim 1, characterized in that: Reinforcing fibers include glass fiber, carbon fiber, and basalt fiber.

4. The prepreg for non-autoclave molding of composite liquid oxygen tank according to claim 1, characterized in that: The epoxy resin includes one or more of bisphenol A type solid epoxy resin, bisphenol A type liquid epoxy resin, tetrafunctional glycidylamine type epoxy resin, novolac epoxy resin, and bisphenol S epoxy resin; The curing agent includes one or more of diaminodiphenyl sulfone, dicyandiamide, urea accelerator, imidazole, diaminoimidazole triazine complex, and boron trifluoride monoethylamine; The toughening agent includes one or more of polyethersulfone, polyetheretherketone, hyperbranched polymer, nitrile rubber, and silicone rubber; The modifier includes one or more of triphenylphosphine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, hexachlorocyclotriphosphazene, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide, polyphosphazene, and tetrabromobisphenol A; The viscosity regulator includes one or more of phenyl glycidyl ether, polypropylene glycol diglycidyl ether, tricresyl phosphate, triethyl phosphate, liquid polybutadiene rubber, liquid silane, and polyurethane.

5. The prepreg for non-autoclave molding of composite liquid oxygen tank according to claim 1, characterized in that: The viscosity of the resin matrix at room temperature is 300~1500Pa·S; at 70~80℃, the viscosity is 8~20Pa·S, and the gel time is 100~500min; at 120~130℃, the viscosity is 0.5~5Pa·S, and the gel time is 30~100min.

6. A method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to any one of claims 1 to 5, characterized in that: The steps include: S1, mixing epoxy resin, curing agent, toughening agent and viscosity regulator to obtain a base resin; S2, blending the modifier, viscosity regulator and toughening agent to obtain a compound component, ensuring that the viscosity of the compound component is consistent with that of the base resin; S3, blending the base resin and the compounding components to obtain a prepreg resin matrix; S4. Prepreg for non-autoclave molding of composite liquid oxygen tank is obtained through coating and reinforcing fiber impregnation process.

7. The method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to claim 6, characterized in that: In the step S2, the modifier, viscosity regulator and toughening agent are blended at 80-150° C., and the ratio of the modifier, toughening agent and viscosity regulator is adjusted to ensure that the viscosity of the compounded component is consistent with the viscosity of the base resin.

8. The method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to claim 6, characterized in that: In the step S4, the temperature is adjusted to 70-80° C. so that the viscosity of the resin matrix is ​​8-20 Pa·S, and a coating process is adopted. The coating speed is adjusted to 0.5-5 m / min and the gap between the rubber rollers is 0.01-0.2 mm to control the surface density of the adhesive film; the adhesive film is impregnated on the reinforcing fiber fabric, and the impregnation temperature is controlled to 70-80° C. so that the viscosity of the resin matrix is ​​8-20 Pa·S. The prepreg for non-autoclave molding of a composite material liquid oxygen tank is obtained by adjusting the impregnation speed and the gap between the pressure rollers.

9. The method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to claim 8, characterized in that: In the step S4, the impregnation speed is adjusted to 2-3 m / min and the gap between the pressure rollers is adjusted to 0.2-0.5 mm to obtain a prepreg with an impregnation degree of 70-80%. The prepreg is suitable for non-autoclave molding of a composite material liquid oxygen tank with a thickness of 2-3 mm.

10. The method for preparing a prepreg for non-autoclave molding of a composite material liquid oxygen tank according to claim 8, characterized in that: In the step S4, the impregnation speed is adjusted to 0.5-2 m / min, and the gap between the pressure rollers is adjusted to 0.05-0.2 mm, so as to obtain a prepreg with an impregnation degree of 80-90%. The prepreg is suitable for non-autoclave molding of a composite material liquid oxygen tank with a thickness of 0.5-2 mm.

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