PBO fiber reinforced resin matrix composite material with strong high-temperature interface and preparation method of PBO fiber reinforced resin matrix composite material

Abstract

The invention discloses a PBO fiber reinforced resin-based composite material with a strong high-temperature interface and a preparation method of the PBO fiber reinforced resin-based composite material, and belongs to the technical field of composite materials. The preparation method comprises the following steps: cleaning PBO fibers; activating the surface of the PBO fiber; the PBO fibers are soaked in a silicon resin solution for a period of time, then taken out, drained and cleaned, and then put into a drying oven for drying treatment; after drying is finished, gamma-ray irradiation treatment is conducted on the PBO fibers; the PBO fiber subjected to irradiation treatment is used as a reinforcing material to be compounded with a resin matrix, then high-temperature curing forming is performed by adopting a forming method, and the PBO fiber reinforced resin matrix composite with the strong high-temperature interface is obtained. The problems that the PBO fiber reinforced resin-based composite material is low in interfacial strength and prone to layering damage under the long-time high-temperature condition can be solved.

Description

Technical Field

[0001] The invention provides a PBO fiber reinforced resin-based composite material with a strong high-temperature interface and a preparation method thereof, belonging to the technical field of composite materials. Background Art

[0002] Resin-based wave-transparent composite materials are key structural and functional integrated composite materials. They are widely used in aircraft antenna wave-transparent components. They have the characteristics of being "transparent" to electromagnetic waves, ensuring smooth transmission of electromagnetic waves and reducing interface reflection and loss of electromagnetic waves. PBO fiber (poly(p-phenylene benzobisazole) fiber) is a linear polyaromatic heterocyclic liquid crystal polymer molecule. PBO fiber has higher specific strength, specific modulus and high temperature resistance than aramid, so it is regarded as a new generation of super fiber for advanced structural composite materials in aerospace. Due to its good electromagnetic wave permeability and high temperature stability, especially its low dielectric constant, very low and stable dielectric loss, it is an ideal material for making wave-transparent components. However, the surface chemical activity of PBO fiber is low and its inertness is large. When used as a reinforcing material, the interface bonding strength between the fiber and the resin matrix is ​​low, especially under high temperature conditions, the interface strength cannot meet the use requirements of special environments and components. Therefore, the PBO fiber needs to be surface modified and activated.

[0003] At present, Chen Xiangdong and others have invented a surface modification method for PBO fibers, specifically using modified graphene oxide to modify PBO fibers, and the specific steps are as follows: (1) preparation and modification of graphene oxide; (2) carboxylation treatment of PBO fibers; (3) grafting modified graphene oxide on the surface of PBO fibers; through the above modification, the modified graphene oxide is grafted on the surface of PBO fibers, and the active functional groups on the surface of modified graphene oxide are used to improve the roughness and specific surface area, which can solve the problem that the surface of PBO fibers is smooth and lacks functional groups, resulting in poor adhesion to the polymer matrix, and at the same time improve its mechanical properties. Yan Hongxia and others have invented a surface modification method for PBO fibers, using a secondary activation method to modify PBO fibers to reduce damage to the fibers and improve the modification effect. That is, firstly, PBO is pretreated with hydrogen peroxide and enzyme to introduce cleaning groups on its surface, and then condensed with a self-linking agent to introduce different cleaning functional groups on its surface to meet the needs of different thermosetting resins, so as to achieve the purpose of improving the interfacial bonding performance between the fiber and the resin. Huang Yudong et al. invented a surface modification treatment method for PBO fiber, a reinforcing material for polymer-based composite materials, in which the PBO fiber is immersed in a plastic or glass container containing a grafting solution, and then the container is sealed and irradiated with y rays. After the irradiation is completed, the PBO fiber is taken out from the container after being placed for 20 to 30 hours. These methods are mainly aimed at the modification of PBO fiber in medium and low temperature use environments, and are not suitable for the modification of fiber interfaces under high and ultra-high temperature conditions. This problem needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to propose a PBO fiber reinforced resin-based composite material with a strong high-temperature interface and a preparation method thereof, to construct a high-temperature cross-linked structure, and to solve the problem that the interface strength of the PBO fiber reinforced resin-based composite material is low and easy to be delaminated and damaged under long-term high-temperature conditions.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a PBO fiber-reinforced resin-based composite material with a strong high-temperature interface comprises the following steps:

[0007] 1) Cleaning PBO fibers;

[0008] 2) Activating the surface of PBO fiber;

[0009] 3) immersing the PBO fiber in the silicone resin solution for a period of time, then taking it out to drain and wash it, and then putting it in an oven for drying; after drying, the PBO fiber is irradiated with γ-rays;

[0010] 4) The irradiated PBO fibers are used as reinforcing materials, compounded with a resin matrix, and then subjected to high-temperature curing molding using a molding method to obtain a PBO fiber-reinforced resin-based composite material with a strong high-temperature interface.

[0011] Furthermore, in step 1), the PBO fibers are cleaned by an organic solvent cleaning method, a high temperature treatment method or an ultrasonic cleaning method.

[0012] Furthermore, in step 2), the activation treatment of the PBO fiber surface is performed by chemical etching, chemical grafting, plasma treatment or irradiation treatment.

[0013] Furthermore, in step 3), the PBO fiber is immersed in a silicone resin solution for 0.5 to 4 hours, and the mass fraction of the resin solution is 0.5% to 5%.

[0014] Furthermore, in step 3), the PBO fibers are drained and laid flat on release paper, left for 1 to 5 hours, and then rinsed again with ethanol for 1 to 3 times.

[0015] Furthermore, in step 3), the drying treatment conditions are: treatment at 200-250° C. for 1-2 hours.

[0016] Furthermore, in step 3), the γ-ray irradiation dosage is 200 to 800 kGy, and the irradiation rate is 5 to 20 kGy / h.

[0017] Furthermore, in step 3), after the γ-ray irradiation treatment is completed, the PBO fiber is cleaned with ethanol, dried and sealed for storage.

[0018] Furthermore, in step 4), the resin matrix is ​​selected from phenolic resin, polyimide resin, polyarylacetylene resin or phthalonitrile resin; and the high temperature curing molding is performed by compression molding, vacuum bag molding, autoclave molding or RTM molding.

[0019] A PBO fiber reinforced resin-based composite material with a strong high-temperature interface is prepared by the preparation method.

[0020] The beneficial effects of the present invention compared with the prior art are as follows:

[0021] (1) After the silicone resin cured product is grafted onto the surface of the PBO fiber, the present invention uses high-energy radiation treatment to post-treat the silicone resin cured product to cause a graft copolymerization reaction. On the one hand, it can remove small molecules and low molecular structures in the cured product, that is, structures that are not resistant to high temperatures, and the remaining cured product is a high-temperature resistant structure with a "-Si-O" structure as a skeleton; on the other hand, the radiation treatment is beneficial to improving the surface activity and surface roughness of the PBO fiber. The two interact with each other to jointly improve the interfacial bonding strength between the fiber and the resin. Moreover, the grafting reaction only occurs on the cortex of the fiber, so the orientation structure of the PBO molecular chain is not affected and the mechanical properties of the fiber are not reduced.

[0022] (2) The present invention stably constructs a "-Si-O" structure solid on the surface of the PBO fiber, thereby improving the surface roughness and specific surface area of ​​the fiber, increasing the mechanical riveting effect between the fiber and the resin matrix, and improving the interface strength. After testing, after being kept at 350°C for 30 minutes, the interlaminar shear strength is ≥14.1MPa, an increase of 71.9%. The results show that the high-temperature mechanical strength and thermal stability of the PBO fiber composite material are significantly improved.

[0023] (3) The yarn balls wound by the PBO fibers in the method of the present invention do not need to be separated or cleaned before and after irradiation. The operation is simple, the process is stable, and the quality is reliable. The method is suitable for the preparation of large-sized, complex-structured, high-temperature-resistant composite materials and is suitable for industrial production. DETAILED DESCRIPTION

[0024] In order to make the various technical features and advantages or technical effects in the above technical solutions of the present invention more obvious and easy to understand, they are described in detail below.

[0025] The method for preparing a PBO fiber-reinforced resin-based composite material with a strong high-temperature interface of the present invention comprises the following steps:

[0026] 1. Cleaning PBO fiber cloth

[0027] The PBO fiber cleaning method can adopt known techniques, such as heating cleaning method with organic solvents such as acetone, ethanol, xylene, toluene, ethyl acetate, high temperature treatment method, or ultrasonic cleaning method to remove sizing agent and oil stains on the fiber surface. Those skilled in the art will determine the corresponding cleaning method according to actual conditions.

[0028] 2. Surface activation treatment of PBO fiber

[0029] The method of activating the surface of PBO fiber can be chemical etching, chemical grafting, plasma treatment or irradiation treatment. The treatment process is mainly to improve the surface activity of the fiber and increase the content of polar groups. Those skilled in the art can determine the corresponding surface activation method based on existing means.

[0030] 3. PBO fiber surface grafting and post-treatment

[0031] 3.1. Prepare silicone resin solution: dissolve silicone resin in corresponding solvent, with the mass fraction of resin solution being 0.5% to 5%;

[0032] 3.2. PBO fiber surface grafting treatment: immerse the PBO fiber in the silicone resin solution, take it out after immersion for 0.5 to 4 hours, drain the excess resin solution, spread it on the release paper, leave it for 1 to 5 hours, and then rinse it again with ethanol 1 to 3 times. Then put the PBO fiber into the oven and treat it at 200 to 250℃ for 1 to 2 hours. After taking it out, place the PBO fiber in a γ-ray irradiation environment, with an irradiation dose of 200 to 800 kGy and an irradiation rate of 5 to 20 kGy / h to remove small molecular groups such as methyl and ethyl in the silicone resin, and promote the agglomeration of the silicone resin into particles. After irradiation treatment, clean it with ethanol, dry it, and seal it for storage.

[0033] 4. Composite material molding

[0034] The PBO fiber obtained after irradiation treatment is used as a reinforcing material and compounded with a resin matrix, which includes but is not limited to phenolic resin, polyimide resin, polyaryl acetylene resin, phthalonitrile resin, etc. The PBO fiber-reinforced resin-based composite material with a strong high-temperature interface is prepared by high-temperature curing and molding using common material molding methods such as molding, vacuum bag, autoclave or RTM.

[0035] Three embodiments are listed below:

[0036] Example 1: Preparation of PBO fiber cloth reinforced polyimide resin composite material with strong high temperature interface

[0037] 1. Cleaning PBO fiber

[0038] Use acetone to clean the PBO fiber. Place the PBO fiber in a fiber cleaning device, add acetone to cover the fiber, seal the cleaning device, connect condensation water and heated circulating water, control the temperature to 56°C, treat for 24 hours, take out, rinse with acetone, and place in a fume hood to remove the acetone.

[0039] 2. PBO fiber surface activation

[0040] Treat the PBO fiber with nitric acid solution. Prepare a 30%wt nitric acid solution, immerse the PBO fiber in the solution, soak it at 25°C for 4 hours, then take it out and rinse it with distilled water until the pH is greater than 6.0. Treat the activated PBO fiber at 100°C for 2 hours and seal it for storage.

[0041] 3. PBO fiber surface grafting treatment

[0042] 3.1. Prepare silicone resin solution: dissolve Dow Corning 0806 silicone resin in xylene solvent, with the mass fraction of the resin solution being 0.5%;

[0043] 3.2. Fiber surface grafting treatment: immerse the PBO fiber cloth in step 2 in the silicone resin solution, take it out after immersion for 2 hours, drain the excess resin solution, spread it on the release paper, leave it for 5 hours, and rinse it again with ethanol twice. Then put the fiber into the oven and treat it at 250℃ for 2 hours. After taking it out, place the dried PBO fiber cloth in the irradiation plant, irradiate it with 200kGy, and the irradiation rate is 5kGy / h. After irradiation treatment, clean it with ethanol, dry it and seal it for storage.

[0044] 4. Composite material molding

[0045] PBO fiber reinforced polyimide composites were prepared by compression molding: a polyimide resin solution with a mass fraction of 40% was prepared, and a prepreg was prepared according to a mass ratio of resin: PBO fiber = 50:50, and then the solvent was removed. 20 prepregs were cut into 300mm×300mm pieces, aligned and laid in the female mold, and placed in a press for curing after the mold was closed. The curing system was 330℃ / 2h→350℃ / 2h→380℃ / 2h, and then cooled to room temperature for demoulding.

[0046] After testing, the properties of the PBO fiber reinforced polyimide resin composite material prepared by the above method and the unmodified composite material are shown in Table 1. It can be seen that the bending strength of the sample treated by the present invention is increased by 58.6% and the interlaminar shear strength is increased by 54.9% compared with the unmodified sample.

[0047] Table 1 Properties of PBO fiber reinforced polyimide resin composites

[0048]

[0049] Example 2: Preparation of PBO fiber reinforced polyaryl acetylene resin composite material with strong high temperature interface

[0050] 1. Cleaning PBO fiber

[0051] Use acetone to clean the PBO fiber. Place the PBO fiber in a fiber cleaning device, add acetone to cover the fiber, seal the cleaning device, connect condensation water and heated circulating water, control the temperature to 56°C, treat for 24 hours, take out, rinse with acetone, and place in a fume hood to remove the acetone.

[0052] 2. PBO fiber surface activation

[0053] Plasma treatment of PBO fiber. Air plasma treatment of PBO fiber, output power of 400W, treatment time of 1min, after treatment, PBO fiber is immediately sealed and vacuumed for storage or immediately proceed to step 3.2.

[0054] 3. Grafting treatment of fiber surface

[0055] 3.1. Prepare silicone resin solution: dissolve the homemade HT-01 silicone resin in acetone solvent, with the mass fraction of the resin solution being 2%;

[0056] 3.2. Fiber surface grafting treatment: immerse the PBO fiber cloth in step 2.2 in the silicone resin solution, take it out after immersion for 4 hours, drain the excess resin solution, spread it on the release paper, leave it for 1 hour, and rinse it again with ethanol for 3 times. Then put the fiber into the oven and treat it at 200℃ for 1.5 hours. After taking it out, place the dried PBO fiber in the irradiation plant, irradiate it with 800kGy, irradiate it at a rate of 20kGy / h, clean it with ethanol after irradiation, dry it and seal it for storage.

[0057] 4. Composite material molding

[0058] RTM molding was used to prepare PBO fiber reinforced polyaryl acetylene resin composite materials: PBO fiber cloth was cut according to the cavity size, aligned and laid in the mold, and the mold was sealed. The injection temperature was 95°C and the injection pressure was 0.25MPa. The curing system was 120°C / 2h→150°C / 2h→180°C / 2h→210°C / 2h→230°C / 2h→250°C / 2h, and the mold was demoulded after cooling to room temperature.

[0059] After testing, the properties of the PBO fiber reinforced polyaryl acetylene resin composite material prepared by the above method and the unmodified composite material are shown in Table 2. It can be seen that the bending strength of the sample treated by the present invention is increased by 66.5% and the interlaminar shear strength is increased by 71.9% compared with the unmodified sample.

[0060] Table 2 Properties of PBO fiber reinforced polyaryl acetylene resin composites

[0061] Sample (400℃ / 10min) The present invention Unmodified Bending strength(MPa) 121.6 73 Interlaminar shear strength (MPa) 14.1 8.2 Dielectric constant (400℃) 3.23～3.43 3.26～3.46

[0062] Example 3: Preparation of PBO fiber unidirectional tape reinforced phenolic resin composite material with strong high temperature interface

[0063] 1. Cleaning PBO fiber

[0064] Use acetone to clean the PBO fiber. Place the PBO fiber in a fiber cleaning device, add acetone to cover the fiber, seal the cleaning device, connect condensation water and heated circulating water, control the temperature to 56°C, treat for 24 hours, take out, rinse with acetone, and place in a fume hood to remove the acetone.

[0065] 2. Fiber surface activation

[0066] The PBO fiber was treated with a silane coupling agent KH-550 solution. A 1%wt KH550 ethanol solution was prepared, and the PBO fiber was immersed in the solution. After soaking at 50°C for 5 hours, the fiber was taken out and rinsed with distilled water for 3 times. Then, the fiber was placed in a 120°C oven for 2 hours. After being taken out, it was sealed and stored.

[0067] 3. Grafting treatment of fiber surface

[0068] 3.1. Prepare silicone resin solution: dissolve Zhonglan Chenguang 805 silicone resin in xylene / acetone mixed solvent, with the mass fraction of the resin solution being 5%;

[0069] 3.2. Fiber surface grafting treatment: immerse the PBO fiber in step 2.2 in the silicone resin solution, take it out after immersion for 0.5 hours, drain the excess resin solution, spread it on the release paper, leave it for 3 hours, and then rinse it again with ethanol for 3 times. Then put the fiber into the oven and treat it at 200℃ for 1 hour. After taking it out, place the dried PBO fiber in the irradiation plant, irradiate it with 500kGy, irradiate it at a rate of 10kGy / h, and clean it with ethanol after irradiation treatment, dry it and seal it for storage.

[0070] 4. Composite material molding

[0071] The PBO fiber reinforced phenolic resin composite material was prepared by autoclave molding: a phenolic resin solution with a mass fraction of 40% was prepared, and a prepreg was prepared according to a mass ratio of resin: PBO fiber = 60:40, and then the solvent was removed. The prepreg was aligned and laid in the mold, and high-temperature vacuum auxiliary materials were laid. The curing pressure was 2.0MPa, and the curing system was 150℃ / 2h→180℃ / 2h→200℃ / 2h→250℃ / 2h, and it was cooled to room temperature and demoulded.

[0072] After testing, the properties of the PBO fiber reinforced phenolic resin composite material prepared by the above method and the unmodified composite material are shown in Table 3. It can be seen that the bending strength of the sample treated by the present invention is increased by 61.2% and the interlaminar shear strength is increased by 66.6% compared with the unmodified sample.

[0073] Table 3 Properties of PBO fiber reinforced phenolic resin composites

[0074] Sample (350℃ / 30min) The present invention Unmodified Bending strength(MPa) 158 98 Interlaminar shear strength (MPa) 13.0 7.8 Dielectric constant (350℃) 3.39～3.59 3.37～3.57

[0075] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions of the technical solutions of the present invention made by ordinary technicians in the field should all be included in the protection scope of the present invention. The protection scope of the present invention shall be based on what is defined in the claims.

Claims

1. A method for preparing a PBO fiber-reinforced resin-based composite material with a strong high-temperature interface, characterized in that: The following steps are involved: 1) Cleaning PBO fibers; 2) Activating the surface of PBO fiber; 3) Immerse the PBO fiber in the silicone resin solution for a period of time, then take it out, drain and wash it, and then put it in an oven for drying; After drying, the PBO fiber is irradiated with γ-rays; 4) The irradiated PBO fibers are used as reinforcing materials, compounded with a resin matrix, and then subjected to high-temperature curing molding using a molding method to obtain a PBO fiber-reinforced resin-based composite material with a strong high-temperature interface.

2. The preparation method according to claim 1, characterized in that In step 1), the PBO fibers are cleaned by organic solvent cleaning, high temperature treatment or ultrasonic cleaning.

3. The preparation method according to claim 1, characterized in that: In step 2), the activation treatment of the PBO fiber surface is carried out by chemical etching, chemical grafting, plasma treatment or irradiation treatment.

4. The preparation method according to claim 1, characterized in that: In step 3), the PBO fiber is immersed in a silicone resin solution for 0.5 to 4 hours, and the mass fraction of the resin solution is 0.5% to 5%.

5. The preparation method according to claim 1, characterized in that: In step 3), the PBO fibers are drained and laid flat on release paper, left for 1 to 5 hours, and then rinsed again with ethanol for 1 to 3 times.

6. The preparation method according to claim 1, characterized in that: The drying treatment conditions in step 3) are: treatment at 200-250° C. for 1-2 hours.

7. The preparation method according to claim 1, characterized in that: In step 3), the γ-ray irradiation dosage is 200 to 800 kGy, and the irradiation rate is 5 to 20 kGy / h.

8. The preparation method according to claim 1, characterized in that: Step 3) After the γ-ray irradiation treatment, the PBO fiber is cleaned with ethanol, dried and sealed for storage.

9. The preparation method according to claim 1, characterized in that: In step 4), the resin matrix is ​​selected from phenolic resin, polyimide resin, polyarylacetylene resin or phthalonitrile resin; high temperature curing molding adopts compression molding, vacuum bag molding, autoclave molding or RTM molding.

10. A PBO fiber reinforced resin-based composite material with a strong high temperature interface, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

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