Aramid natural rubber composite material and preparation method thereof

Abstract

The invention discloses an aramid fiber natural rubber composite material and a preparation method thereof. The material is prepared by the following method: step A, carrying out gum dipping treatment on aramid fibers or aramid fabrics by adopting a gum dipping solution; step B, drying the impregnated aramid fiber or aramid fabric; step C, irradiating the impregnated aramid fiber or aramid fabric by adopting electron beams so as to modify the surface of the aramid fiber or aramid fabric; and step D, carrying out hot press molding on the surface-modified aramid fiber or aramid fabric. The method is easy and convenient to operate and high in practicability, the contact area of the aramid fiber and the impregnation liquid is increased by coating the surface with polydopamine, and the surface active point location of the aramid fiber is increased. Meanwhile, the latex dipping emulsion containing natural latex is prepared, so that the binding power between a fiber surface rubber film and rubber is improved.

Description

Technical Field

[0001] The invention belongs to the field of special materials, and in particular relates to an aramid natural rubber composite material and a preparation method thereof. Background Art

[0002] Para-aramid fiber, full name of poly(p-phenylene terephthalamide) (PPTA) fiber, is an organic polymer fiber synthesized from terephthaloyl chloride and p-phenylenediamine. Because the amide bond is connected at the 1st and 4th positions of the two benzene rings, it is also called aramid 1414. It has excellent properties such as high specific strength, high specific modulus, high temperature resistance and flame retardancy. It is often used as a reinforcing material for rubber matrices, such as tubular airbags, cord fabrics, etc. However, the surface of para-aramid is dense and has fewer active groups. After being directly compounded with rubber, the interfacial adhesion is poor, resulting in low peel strength of the composite material.

[0003] The commonly used method at present is to use the "formaldehyde-resorcinol-latex" system dipping solution to treat the aramid surface and then dry it to improve the surface activity of the aramid. However, since the para-aramid surface has few active sites, the dipping solution is easy to peel off under the action of external force after forming a film on the aramid surface, resulting in the destruction of the aramid-rubber interface. Summary of the invention

[0004] The purpose of the present invention is to provide a new method for preparing a para-aramid / rubber composite material based on the prior art, so as to enhance the bonding force between the dipping solution and the aramid after film formation, so as to improve the aramid-rubber interface bonding strength.

[0005] The purpose of the present invention can be achieved by the following measures: An aramid natural rubber composite material is prepared by the following method: Step A, using a dipping solution to dipping aramid fiber or aramid fabric; Step B, drying the dipped aramid fiber or aramid fabric; Step C, irradiating the dipped aramid fiber or aramid fabric with an electron beam to modify the surface; Step D: hot-pressing the surface-modified aramid fiber or aramid fabric.

[0006] The present invention also includes a method for preparing an aramid natural rubber composite material, which also includes the above steps AD.

[0007] In a preferred embodiment, in step A, the composition of the dipping solution includes: 2-8 parts of carbon nanotubes, 13.6-16.3 parts of softened water, 37.3-40.5 parts of butylpyrrolidone latex, 43.4-47.1 parts of RF intermediate liquid, 0.4-0.6 parts of ammonia water, and the total amount of each component is 100 parts.

[0008] In a preferred embodiment, in step A, the weight ratio of each component in the formula of RF inter-methylene glycol solution is: softened water: sodium hydroxide: resorcinol: formaldehyde = 38.9-44.7: 0.04-0.05: 1.58-1.95: 2.3-2.7.

[0009] In a preferred embodiment, in step A, the stretching tension of the dipping treatment is 4-10 KN, the pH is 7-8.5, and the time is 30s-60s.

[0010] In a preferred embodiment, in step B, the drying temperature is 140-160 degrees, and the drawing tension is 5-7 KN.

[0011] In a preferred embodiment, in step C, the irradiation time is 5-20 minutes, and the energy range is 0.6 MeV to 2 MeV.

[0012] In a preferred embodiment, in the hot pressing molding of step D, the surface-modified aramid fiber or aramid fabric is sandwiched between two rubber sheets and hot pressed using a flat plate vulcanizer for 20-40 minutes at a temperature of 150°C.

[0013] Beneficial effects of the present invention: The method of the invention is simple and convenient to operate, and has strong practicality. The contact area between aramid fiber and dipping solution is increased by coating the surface with polydopamine, thereby increasing the active sites on the surface of aramid fiber. Meanwhile, the dipping solution containing natural latex is prepared to increase the bonding force between the fiber surface film and rubber. DETAILED DESCRIPTION

[0014] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0015] Example 1 An aramid natural rubber composite material is prepared by the following steps: 1. Prepare the dipping solution, including 2-8 parts of carbon nanotubes, 13.6-16.3 parts of softened water, 37.3-40.5 parts of butylpyrrolidone latex, 43.4-47.1 parts of RF intermediate liquid, 0.4-0.6 parts of ammonia water, and the total amount of each component is 100 parts.

[0016] The weight ratio of each component in the formula of RF intermediate nail liquid is: softened water: sodium hydroxide: resorcinol: formaldehyde = 39: 0.05: 1.95: 2.3.

[0017] 2. Use dipping solution to treat aramid fiber, with a drafting tension of 6KN, adjusting the pH to 8, and a time of 40s.

[0018] 3. Dry the dipped aramid at a temperature of 155 degrees and a drawing tension of 6 KN.

[0019] 4. The dipped aramid fiber is irradiated with an electron beam for 10 minutes with an energy range of 1MeV to promote chemical cross-linking between the adhesive film (dried and solidified adhesive solution) and the fiber to improve adhesion.

[0020] 5. The surface-modified aramid fibers are sandwiched between two rubber sheets and hot-pressed using a flat-plate vulcanizer for 40 minutes at a temperature of 150°C.

[0021] Example 2 An aramid natural rubber composite material is prepared by the following steps: 1. Prepare the dipping solution, including 2-8 parts of carbon nanotubes, 13.6-16.3 parts of softened water, 37.3-40.5 parts of butylpyrrolidone latex, 43.4-47.1 parts of RF intermediate liquid, 0.4-0.6 parts of ammonia water, and the total amount of each component is 100 parts.

[0022] The weight ratio of each component in the formula of RF intermediate nail liquid is: softened water: sodium hydroxide: resorcinol: formaldehyde = 43: 0.04: 1.58: 2.6.

[0023] 2. Treat the aramid fabric with dipping solution, with a drafting tension of 8KN, PH7.5, and a time of 50s.

[0024] 3. Dry the dipped aramid at a temperature of 150 degrees and a drawing tension of 6 KN.

[0025] 4. The dipped aramid fiber is irradiated with an electron beam for 8 minutes with an energy range of 1.5 MeV, which promotes chemical cross-linking between the adhesive film (the dried and solidified adhesive liquid) and the fiber to improve the adhesion.

[0026] 5. The surface-modified aramid fabric is sandwiched between two pieces of rubber and hot-pressed using a flat-plate vulcanizer for 30 minutes at a temperature of 150°C.

[0027] Comparative Example 1 The aramid natural rubber composite material was prepared by the method of Example 1, wherein step 4 was not used.

[0028] Test Case The performance tests were conducted on the aramid natural rubber composite materials of Examples 1-2 and Comparative Example 1. The results are shown in Table 1.

[0029] Table 1 The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that it is still possible to modify the technical solutions described in the aforementioned embodiments, or to perform equivalent replacements on some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aramid natural rubber composite material, characterized in that It is prepared by the following method: Step A, using a dipping solution to perform dipping treatment on the aramid fiber or aramid fabric; Step B, drying the dipped aramid fiber or aramid fabric; Step C, irradiating the dipped aramid fiber or aramid fabric with an electron beam to modify the surface; Step D: hot-pressing the surface-modified aramid fiber or aramid fabric.

2. The aramid natural rubber composite material according to claim 1, characterized in that In step A, the composition of the dipping solution includes: 2-8 parts of carbon nanotubes, 13.6-16.3 parts of softened water, 37.3-40.5 parts of butylpyrrolidone latex, 43.4-47.1 parts of RF intermediate liquid, 0.4-0.6 parts of ammonia water, and the total amount of each component is 100 parts.

3. The aramid natural rubber composite material according to claim 2, characterized in that In step A, the weight ratio of each component in the formula of the RF intermediate nail liquid is: softened water: sodium hydroxide: resorcinol: formaldehyde = 38.9-44.7: 0.04-0.05: 1.58-1.95: 2.3-2.

7.

4. The aramid natural rubber composite material according to claim 1, characterized in that In step A, the dipping treatment has a drawing tension of 4-10 KN, a pH of 7-8.5, and a time of 30s-60s.

5. The aramid natural rubber composite material according to claim 1, characterized in that In step B, the drying temperature is 140-160 degrees, and the drawing tension is 5-7 KN.

6. The aramid natural rubber composite material according to claim 1, characterized in that In step C, the irradiation time is 5-20 minutes, and the energy range is 0.6 MeV to 2 MeV.

7. The aramid natural rubber composite material according to claim 1, characterized in that In the hot pressing molding of step D, the surface-modified aramid fiber or aramid fabric is sandwiched between two rubber sheets and hot pressed using a flat plate vulcanizer for 20-40 minutes at a temperature of 150°C.

8. A method for preparing an aramid natural rubber composite material, characterized in that The steps include: Step A, using a dipping solution to perform dipping treatment on the aramid fiber or aramid fabric; Step B, drying the dipped aramid fiber or aramid fabric; Step C, irradiating the dipped aramid fiber or aramid fabric with an electron beam to modify the surface; Step D: hot-pressing the surface-modified aramid fiber or aramid fabric.

9. The method for preparing the aramid natural rubber composite material according to claim 8, characterized in that In step A, the composition of the dipping solution includes: 2-8 parts of carbon nanotubes, 13.6-16.3 parts of softened water, 37.3-40.5 parts of butylpyrrolidone latex, 43.4-47.1 parts of RF intermediate nail liquid, 0.4-0.6 parts of ammonia water, and the total amount of each component is 100 parts; the weight ratio of each component in the formula of the RF intermediate nail liquid is: softened water: sodium hydroxide: resorcinol: formaldehyde = 38.9-44.7: 0.04-0.05: 1.58-1.95: 2.3-2.7; the drawing tension of the dipping treatment is 4-10KN, PH7-8.5, and the time is 30s-60s.

10. The method for preparing the aramid natural rubber composite material according to claim 8, characterized in that In step B, the drying temperature is 140-160 degrees, and the drawing tension is 5-7 KN; in step C, the irradiation time is 5-20 minutes, and the energy range is 0.6MeV to 2MeV; in the hot pressing molding of step D, the surface-modified aramid fiber or aramid fabric is sandwiched between two pieces of rubber, and hot pressing molding is performed using a flat plate vulcanizer, the hot pressing time is 20-40 minutes, and the temperature is 150°C.

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