TWI858859B - Method for manufacturing carbon fiber composite material - Google Patents

Abstract

A method for manufacturing carbon fiber composite material is provided. A pre-mixed material including a polyamide material and a polymer dispersant is provided. The pre-mixed material is heated such that the polyamide material undergoes a dispersion process by the polymer dispersant so as to form an immersion material. Carbon fiber is immersed in the immersion material at a process temperature ranging from 320°C to 350°C so that the polyamide material processed by the polymer dispersant is attached onto the carbon fiber. A viscosity of the immersion material ranges from 10 Pa‧s to 100 Pa‧s. On a cooling condition, the polyamide material processed by the polymer dispersant is fixed on the carbon fiber, and a carbon fiber composite material is obtained.

Description

Method for preparing carbon fiber composite material

The present invention relates to a method for preparing a carbon fiber composite material, and in particular to a method for preparing a carbon fiber composite material suitable for long carbon fibers.

Carbon fiber itself has the characteristics of being not easy to deform, highly heat-resistant, high-strength, and highly conductive. The strength of carbon fiber is greater than that of steel, but the density of carbon fiber is less than that of aluminum, so it can be widely used in different fields. Carbon fiber is also often added to composite materials to enhance the rigidity of composite materials.

However, the characteristics of carbon fiber itself can easily cause difficulties in the process. For example, when manufacturing carbon fiber composites, carbon fiber is soaked in plastic, so that the plastic adheres to the surface of the carbon fiber and forms a wetting layer. Since carbon fiber and plastic are completely different materials, if the plastic soaking effect is not good, it will lead to uneven quality of the composite material, which will negatively affect the quality of the carbon fiber composite.

Furthermore, when the carbon fiber surface is not completely attached to the plastic, it is easier to get stuck in the impregnation die, causing the production line to be blocked. Therefore, in order to avoid the problem of carbon fiber getting stuck in the die and causing blockage, it is necessary to reduce the amount of carbon fiber impregnated at one time, which will reduce the output of carbon fiber composites.

The existing carbon fiber composite material preparation method has not been able to solve the above-mentioned problem of poor carbon fiber impregnation effect. Therefore, how to improve the plastic impregnation effect on carbon fiber by improving the preparation method and plastic composition to overcome the above-mentioned defects has become one of the important issues that the industry wants to solve.

The technical problem to be solved by the present invention is to provide a method for preparing a carbon fiber composite material in view of the shortcomings of the prior art.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a method for preparing a carbon fiber composite material. The method for preparing a carbon fiber composite material includes the following steps: providing a premix, the premix comprising a polyamide material and a polymer dispersant. The premix is heated so that the polymer dispersant disperses the polyamide material to form an impregnation material. At a processing temperature of 320°C to 350°C, the carbon fiber is immersed in the impregnation material so that the polyamide material dispersed by the polymer dispersant is attached to the carbon fiber, and the viscosity of the impregnation material is 10 Pascal seconds to 100 Pascal seconds. Under cooling conditions, the polyamide material dispersed by the polymer dispersant is fixed on the carbon fiber to obtain a carbon fiber composite material.

In some embodiments, the premix is heated to a temperature in the range of 250°C to 345°C for dispersion.

In some embodiments, the weight average molecular weight of the polymer dispersant is 1000 g/mol to 10000 g/mol.

In some embodiments, the polymer dispersant is a polyolefin polymer dispersant.

In some embodiments, the relative viscosity of the polyamide material is 2.0 to 4.0.

In some embodiments, before the dipping treatment, the carbon fiber undergoes a preheating treatment and a spinning treatment, wherein the preheating temperature in the preheating treatment is 110°C to 130°C.

In some embodiments, the premix further includes a polymer compatibilizer; after the carbon fiber is immersed in the impregnating material, the two ends of the polymer compatibilizer are respectively connected to the polyamide material dispersed by the polymer dispersant and the carbon fiber.

In some embodiments, the polymer compatibilizer has maleic anhydride functional groups, and the total weight of monomers used to synthesize the polymer compatibilizer is 100 weight percent, and 0.5 weight percent to 1.3 weight percent of the monomers have maleic anhydride functional groups.

In some embodiments, the premix further comprises a polyolefin elastomer synthesized from monomers selected from the group consisting of ethylene, 1-propylene, 1-butene, 1-hexene and 1-octene.

In some embodiments, the polyolefin elastomer is selected from the group consisting of ethylene/α-olefin random copolymers, ethylene/α-olefin block copolymers, EPDM rubber elastomers and EPDM rubber elastomers.

One of the beneficial effects of the present invention is that the preparation method of the carbon fiber composite material provided by the present invention can improve the wetting effect of the impregnating material on the carbon fiber through the technical scheme of "heating the premix to allow the polymer dispersant to disperse the polyamide material to form an impregnating material" and "the viscosity of the impregnating material is 10 Pascal seconds to 100 Pascal seconds".

To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only used for reference and description and are not used to limit the present invention.

The following is an explanation of the implementation of the "method for preparing carbon fiber composite materials" disclosed in the present invention through specific concrete embodiments. Technical personnel in this field can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without deviating from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual sizes. Please note in advance. The following implementation will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention. In addition, the term "or" used herein may include any one or more combinations of the associated listed items as appropriate.

In order to improve the wetting effect between carbon fiber and impregnation material, the present invention uses polyamide material and polymer dispersant as impregnation material. The polyamide material can improve the wetting effect of impregnation material on carbon fiber under the dispersion treatment of polymer dispersant. When the impregnation effect is improved, the carbon fiber surface can be completely attached to the impregnation material, and a carbon fiber composite material with uniform quality can be obtained. In addition, during the preparation process, it is less likely to cause the problem of carbon fiber blocking the die head.

Referring to FIG. 1 , the method for preparing the carbon fiber composite material of the present invention includes the following steps.

In step S1, a premix is provided, which includes a polyamide material and a polymer dispersant.

Polyamide materials have the characteristics of high strength and high durability. When polyamide materials are used as impregnation materials for carbon fibers, the strength of carbon fibers can be further improved. Therefore, compared with pure carbon fiber materials, the carbon fiber composite material of the present invention has higher strength and can be used as raw materials for military supplies or automobiles and motorcycles. In addition, the surface of the polyamide material has a large number of hydrophilic amide groups, which is conducive to subsequent other surface treatment processes.

After comprehensively considering the characteristics and processability of the carbon fiber composite material, the relative viscosity of the polyamide material is 2.0 to 4.0, for example, the relative viscosity of the polyamide material can be 2.3, 2.6, 2.9, 3.2, 3.5 or 3.8. However, the present invention is not limited thereto. In an exemplary embodiment, a polymer (nylon 66) formed by condensation copolymerization of hexamethylenediamine and adipic acid or polycaprolactam (nylon 6) can be selected as the polyamide material.

The addition of polymer dispersant can make the polyamide material adhere well to the carbon fiber, thereby improving the wetting effect of the impregnating material on the carbon fiber. Since the melting point of the polyamide material is relatively high (about 280°C), in order to cope with various high-temperature treatment steps in the subsequent process, the present invention uses a polymer dispersant with a higher boiling point to avoid the polymer dispersant evaporating in the treatment step and losing the effect of dispersing the polyamide material.

In an exemplary embodiment, the polymer dispersant is a polyolefin polymer dispersant. The weight average molecular weight of the polymer dispersant is 1000 g/mol to 10000 g/mol, for example, 2000 g/mol, 3000 g/mol, 4000 g/mol, 5000 g/mol, 6000 g/mol, 7000 g/mol, 8000 g/mol or 9000 g/mol.

In this molecular weight range, the polymer dispersant can evenly disperse the polyamide material to achieve the expected dispersion effect. In addition, the polyamide material in the above molecular weight range can have a better dispersion effect with the polymer dispersant in the above molecular weight range.

In step S2, the premix is heated to allow the polymer dispersant to disperse the polyamide material to form a wetted material.

During the dispersion process, the premix can be heated to a temperature range of 250°C to 345°C. In a high temperature environment (250°C to 345°C), the polymer dispersant and the polyamide material will gain energy and rearrange. In terms of microstructure, the polymer dispersant will surround the polyamide material and evenly disperse the polyamide material into multiple molecular clusters. The multiple molecular clusters are stable and will not re-agglomerate.

Specifically, the method of heating the premix for dispersion treatment is to use a twin-screw extruder. The premix is first put into the twin-screw extruder, and the twin-screw extruder is set to extrude at a speed of 220 rpm to 270 rpm and a temperature of 250°C to 345°C, and a wetted material can be obtained. For example, the temperature of heating and mixing the polyamide material and the polymer dispersant can be 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C or 340°C.

In an exemplary embodiment, the impregnating material may also selectively include a polymer compatibilizer. The addition of the polymer compatibilizer can increase the compatibility between the polyamide material and the carbon fiber, and can further enhance the wetting effect between the carbon fiber and the impregnating material.

Specifically, the two ends of the polymer compatibilizer can be connected to the polyamide material (molecular group) and the carbon fiber respectively, so the wetting effect between the carbon fiber and the impregnating material can be improved. In the presence of the polymer dispersant, the polyamide material has been evenly dispersed into multiple molecular groups, and the two ends of the polymer compatibilizer can easily connect the molecular group and the carbon fiber. Therefore, the addition of the polymer compatibilizer can improve the compatibility between the polyamide material and the carbon fiber, thereby improving the wetting effect. Moreover, this wetting effect cannot be achieved by only adding the polymer dispersant or only adding the polymer compatibilizer.

In an exemplary embodiment, the polymer compatibilizer may have a maleic anhydride functional group, and the maleic anhydride functional group may be connected to the polyamide material (molecular group) to enhance the compatibility between the polyamide material and the carbon fiber.

Taking the total weight of monomers of the synthetic polymer compatibilizer as 100 weight percent, 0.5 weight percent to 1.3 weight percent of the monomers have maleic anhydride functional groups. For example, the content of monomers having maleic anhydride functional groups can be 0.6 weight percent, 0.7 weight percent, 0.8 weight percent, 0.9 weight percent, 1.0 weight percent, 1.1 weight percent or 1.2 weight percent. In other words, the grafting rate of maleic anhydride functional groups in the polymer compatibilizer is 0.5% to 1.3%.

In an exemplary embodiment, the polymer compatibilizer can be a polyolefin elastomer having maleic anhydride functional groups (POE-g-MAH) or a polypropylene having maleic anhydride functional groups (PP-g-MAH). Preferably, the polymer compatibilizer is polypropylene having maleic anhydride functional groups.

In an exemplary embodiment, polyolefin elastomers may be selectively added to the impregnating material. The addition of polyolefin elastomers can improve the toughness of carbon fiber composites, especially the toughness in low temperature environments. Compared with polyolefin plastics, polyolefin elastomer molecules have higher elongation and rebound at room temperature, are less likely to permanently deform or break after being stressed, and have lower density.

The monomers for synthesizing the polyolefin elastomer are selected from the group consisting of ethylene, 1-propylene, 1-butene, 1-hexene and 1-octene. In an exemplary embodiment, the polyolefin elastomer is selected from the group consisting of ethylene/α-olefin random copolymer, ethylene/α-olefin block copolymer, ethylene propylene rubber (EPM) and ethylene propylene diene monomer (EPDM).

In step S3, the carbon fiber undergoes a preheating treatment and a yarn spreading treatment. The preheated and spread carbon fiber can have a higher strength, so that it can have a better wetting effect in the next step. The temperature of the preheating treatment can be 110°C to 130°C, but the present invention is not limited thereto.

In an exemplary embodiment, a long carbon fiber with a yarn weight of 800 g/1000 m to 2000 g/1000 m can be used. Preferably, a long carbon fiber with a yarn weight of 1500 g/1000 m to 1800 g/1000 m can also be used. The tensile strength of the carbon fiber is 4500 MPa to 5200 MPa. The tensile modulus of the carbon fiber is 200 GPa to 300 GPa. The elongation of the carbon fiber is 1% to 3%. The density of the carbon fiber is 1.5 g/cm3 to 2.0 g/cm3. The diameter of the carbon fiber is 5 microns to 10 microns.

In step S4, the carbon fiber is immersed in a wet material at a processing temperature of 320°C to 350°C, so that the polyamide material dispersed by the polymer dispersant can be attached to the carbon fiber.

Polyamide material is a high molecular weight material and generally has a relatively high viscosity in the absence of a solvent. In order to achieve a good wetting effect, the viscosity of the wetting material is controlled to be 10 Pascal seconds (Pa‧s) to 100 Pascal seconds.

In order to reduce the viscosity of the impregnation material, in step S1, a polymer dispersant is used to disperse the polyamide material to form a plurality of molecular clusters, which can achieve the effect of reducing the viscosity of the polyamide material. A polymer compatibilizer can also be further added. In addition, in step S2, a higher processing temperature is used, which is also conducive to reducing the viscosity of the polyamide material.

In other words, adding polymer dispersants (and polymer compatibilizers) and adjusting the processing temperature (320°C or 350°C) can reduce the viscosity of the polyamide material and improve the wetting effect between the carbon fiber and the impregnating material.

In the present invention, the viscosity of the impregnant may also be 20 Pascal seconds, 30 Pascal seconds, 40 Pascal seconds, 50 Pascal seconds, 60 Pascal seconds, 70 Pascal seconds, 80 Pascal seconds or 90 Pascal seconds. However, the present invention is not limited thereto.

When the wetting effect between the carbon fiber and the impregnating material is further improved, the impregnating material can adhere to the surface of the carbon fiber and form an impregnating film with uniform thickness. In the past, in order to avoid that part of the carbon fiber surface is not attached to the impregnating liquid, the process parameters are adjusted to form a thicker impregnating film on the carbon fiber surface. When the impregnating effect is improved, the impregnating material can easily adhere to the carbon fiber surface and form an impregnating film, and it is no longer necessary to form such a thick impregnating film on the carbon fiber surface. Therefore, in the present invention, the parameters can be adjusted to form a thinner impregnating film on the carbon fiber surface, and the problem of part of the carbon fiber surface not being attached to the impregnating liquid will not occur.

The thickness of the above-mentioned impregnation film can be quantified as the proportion of carbon fiber in the carbon fiber composite. The thicker the thickness of the impregnation film, the lower the carbon fiber content in the carbon fiber composite. The thinner the thickness of the impregnation film, the higher the carbon fiber content in the carbon fiber composite.

In step S5, under cooling conditions, the polyamide material dispersed by the polymer dispersant is fixed on the carbon fiber to obtain a carbon fiber composite material.

After cooling, the molecular groups formed by the polymer dispersant and the polyamide material can be fixed on the surface of the carbon fiber to form a carbon fiber composite material. The carbon fiber composite material of the present invention has the characteristics of high strength and a hydrophilic surface, which is beneficial to subsequent other surface treatment processes.

The weight of the carbon fiber composite material is compared with the specifications of the original carbon fiber, and then the content ratio of the carbon fiber composite material can be calculated according to the formulation ratio of the impregnating material. Taking the total weight of the carbon fiber composite material as 100 weight percent, the content of the carbon fiber is 15 weight percent to 55 weight percent, the content of the polyamide material is 40 weight percent to 80 weight percent, the content of the polymer dispersant is 0.5 weight percent to 2 weight percent, the content of the polymer compatibilizer is 1 weight percent to 10 weight percent, and the content of the polyolefin elastomer is 1 weight percent to 10 weight percent.

In addition to the above ingredients, antioxidants and lubricants may be optionally added to the raw material mixture. Taking the total weight of the carbon fiber composite material as 100 weight percent, the content of the antioxidant is 0.1 weight percent to 2 weight percent, and the content of the lubricant is 0.1 weight percent to 2 weight percent.

In step S6, the carbon fiber composite material is pelletized to form carbon fiber composite pellets. Specifically, the carbon fiber composite pellets have a diameter of 3 mm and a length of 11 mm.

Please refer to FIG. 2, which is a schematic diagram of the equipment for preparing the carbon fiber composite material of the present invention. In order to make the carbon fiber composite material, the aforementioned impregnation material is put into a twin-screw extruder 10, and the temperature of the twin-screw extruder 10 is set to 250°C to 345°C and the screw speed is 250 rpm. Therefore, the polyamide material and the polymer dispersant can be uniformly mixed in a molten state, so that the polymer dispersant disperses the polyamide material. After the impregnation material is formed, the impregnation material is transported to an impregnation device 20.

The rolled continuous carbon fiber F (Formosa Carbon Fiber, model: TC-36P 24K) is preheated at 120°C and conveyed to the impregnation device 20 after yarn spreading. After impregnation, the surface of the carbon fiber F is completely covered by the impregnation material. After the carbon fiber F passes through the cooling and shaping device 30, it is conveyed to the pelletizer 40, and the carbon fiber composite pellets are produced by the pelletizer 40. Specifically, the diameter of the carbon fiber composite pellets is 3 mm and the length is 11 mm, but the present invention is not limited thereto.

In order to prove that the carbon fiber composite material of the present invention has good physical strength, the carbon fiber composite materials of Examples 1 to 4 and Comparative Examples 1 to 2 were prepared according to the above method and the properties were tested. The main difference between Examples 1 to 4 and Comparative Examples 1 to 2 is that different fibers are used for impregnation, and Comparative Examples 1 to 2 use glass fibers for impregnation.

The specific components of the carbon fiber composite materials of Examples 1 to 4 and Comparative Examples 1 to 2 are listed in Table 1, and the content of each component in Table 1 is expressed in parts by weight. In Examples 1 to 4 and Comparative Examples 1 to 2, the polyamide material can be nylon 6 (hereinafter referred to as PA6) with a relative viscosity of 2.46 or nylon 66 (hereinafter referred to as PA66) with a relative viscosity of 2.7. The polymer dispersant is a polyolefin type super dispersant (also known as a polyolefin type polymer dispersant) with a weight average molecular weight of 1000 to 10000. The polymer compatibilizer is polypropylene with maleic anhydride functional groups. The melting index of the polyolefin elastomer is 8 g/10 min. The model number of the antioxidant is Chinox ^® B1171. The lubricant is polyethylene wax.

The tensile strength and elongation of carbon fiber composites are analyzed according to ISO 527. The tensile modulus of carbon fiber composites is analyzed according to ISO 527. The flexural strength of carbon fiber composites is analyzed according to ISO 178. The flexural modulus/modulus of carbon fiber composites is analyzed according to ISO 178. The impact strength of carbon fiber composites is analyzed according to ISO 178 and measured at 23°C and -40°C. The heat deflection temperature of carbon fiber composites is analyzed according to ISO 178. The flow length of carbon fiber composites is analyzed according to ASTM D3123.

Table 1 Ingredients (parts by weight) Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Comparison Example 1 Comparison Example 2 Polyamide material Type PA6 PA6 PA66 PA66 PA6 PA66 content 45.45 41.45 45.45 41.45 44.95 44.95 Polymer dispersants 1.5 2.0 1.5 2.0 0.5 0.5 Polymer compatibilizer 1 1 1 1 1 1 Polyolefin elastomer 1.5 5 1.5 5 3 3 Antioxidants 0.5 0.5 0.5 0.5 0.5 0.5 Lubricant 0.05 0.05 0.05 0.05 0.05 0.05 Carbon Fiber 50 50 50 50 - - Glass fiber - - - - 50 50 characteristic Tensile strength (MPa) 270.5 286 310 313 228 233 Elongation (%) 3.6 4.1 3.3 4.6 4.2 4.1 Tensile modulus (MPa) 10238.6 11238.5 13238.6 13838.3 7387.6 7530.2 Bending strength (MPa) 440 503 497 497 357 370 Bending elasticity/modulus (MPa) 22121.1 26276 29310 32310 11735 12282 Impact strength (23°C, KJ/m ² ) 19.7 24.0 22.4 26.4 29.5 33.4 Impact strength (-40°C, KJ/m ² ) 18.5 22.8 21.1 24.8 28.4 31.3 Heat deformation temperature (°C) 215 215 255 255 255 215 Flow length (cm) 79 87 69 78 58 66

From the results in Table 1, it can be seen that the preparation method of the carbon fiber composite material of the present invention can improve the wetting effect of the impregnating material on the carbon fiber and overcome the problem of the carbon fiber blocking the die head in the past. After improving the wetting effect, a thinner impregnation layer can be formed on the surface of the carbon fiber to increase the proportion of the carbon fiber component in the carbon fiber composite material.

The carbon fiber composite material of the present invention has the advantage of high carbon fiber content, so that the carbon fiber composite material can have good tensile strength and bending strength. Specifically, with the total weight of the carbon fiber composite material being 100 weight percent, the carbon fiber content can be as high as 40 weight percent or more, preferably 45 weight percent or more, for example: the carbon fiber content is 45 weight percent to 55 weight percent. Compared with the glass fiber composite material (Comparative Examples 1 and 2), the carbon fiber composite material of the present invention has good tensile strength and bending strength.

Please compare Examples 1 and 2 with Examples 3 and 4. When more polyolefin elastomer is added, the elongation, bending elasticity and impact strength of the carbon fiber composite can be improved. Taking the total weight of the carbon fiber composite as 100 weight percent, the content of the polyolefin elastomer is 4 weight percent to 8 weight percent.

Please compare Examples 1 and 3 with Examples 2 and 4. When nylon 66 is used as the polyamide material, the tensile strength, impact strength and thermal deformation temperature of the carbon fiber composite can be improved.

[Beneficial Effects of Embodiments]

One of the beneficial effects of the present invention is that the preparation method of the carbon fiber composite material provided by the present invention can improve the wetting effect of the impregnating material on the carbon fiber through the technical scheme of "heating the premix to allow the polymer dispersant to disperse the polyamide material to form an impregnating material" and "the viscosity of the impregnating material is 10 Pascal seconds to 100 Pascal seconds".

Furthermore, in order to improve the wetting effect of the impregnating material on the carbon fiber, the present invention adds a polymer dispersant and performs a dispersion treatment at a temperature of 250°C to 345°C. In the step of heating the premix, the molecules of the polymer dispersant and the polyamide material will be rearranged. In terms of microstructure, the polyamide material will be evenly dispersed into multiple molecular clusters by the polymer dispersant and will not agglomerate again. When the polyamide material is dispersed by the polymer dispersant, the wetting effect of the impregnating material on the carbon fiber can be improved.

In order to enhance the dispersing effect of the polyamide material, the present invention can use a polymer dispersant of 1000 g/mol to 10000 g/mol to uniformly disperse the polyamide material into molecular clusters of appropriate size to prevent the molecular clusters from agglomerating again during the processing. In addition, the boiling point of the polymer dispersant can be adjusted by controlling the molecular weight to prevent the polymer dispersant from evaporating in the high temperature step. After testing, it was found that when the polymer dispersant is a polyolefin polymer dispersant, it has a better dispersing effect. In addition, it can be used with a polyamide material with a specific molecular weight to form a stable molecular cluster.

Furthermore, a polymer compatibilizer can be further added to the premix. The polymer compatibilizer can enhance the wetting effect between the polyamide material and the carbon fiber. When the polyamide material is dispersed to form multiple molecular clusters, the addition of the polymer compatibilizer can further exert its effect, greatly enhancing the wetting effect between the polyamide material and the carbon fiber.

In the present invention, a polymer compatibilizer having maleic anhydride functional groups is further selected, and the maleic anhydride functional groups can make the two ends of the polymer compatibilizer connect to the polyamide material and the carbon fiber respectively. By adjusting the content of the maleic anhydride functional groups, the wetting effect between the polyamide material and the carbon fiber can be further improved.

The contents disclosed above are only preferred feasible embodiments of the present invention and are not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the specification and drawings of the present invention are included in the scope of the patent application of the present invention.

F:Carbon Fiber

10:Twin screw extruder

20: Immersion device

30: Cooling and shaping device

40: Pelletizer

FIG1 is a flow chart of the steps of the method for preparing the carbon fiber composite material of the present invention.

FIG. 2 is a schematic diagram of an apparatus for preparing the carbon fiber composite material of the present invention.

Claims (9)

A method for preparing a carbon fiber composite material comprises: providing a premix, which comprises a polyamide material, a polymer dispersant and a polymer compatibilizer; wherein the polymer dispersant is a polyolefin type polymer dispersant; heating the premix so that the polymer dispersant disperses the polyamide material to form an impregnation material; and at a processing temperature of 320°C to 350°C, The carbon fiber is immersed in the impregnating material so that the polyamide material dispersed by the polymer dispersant is attached to the carbon fiber, and the viscosity of the impregnating material is 10 Pascal seconds to 100 Pascal seconds; and under cooling conditions, the polyamide material dispersed by the polymer dispersant and the polymer compatibilizer is fixed on the carbon fiber to obtain a carbon fiber composite material. The preparation method as described in claim 1, wherein the premix is heated to a temperature range of 250°C to 345°C to perform the dispersion treatment. The preparation method as described in claim 1, wherein the weight average molecular weight of the polymer dispersant is 1000 g/mol to 10000 g/mol. The preparation method as described in claim 1, wherein the relative viscosity of the polyamide material is 2.0 to 4.0. The preparation method as described in claim 1, wherein, before the impregnation treatment, the carbon fiber undergoes a preheating treatment and a yarn spreading treatment, and the preheating temperature in the preheating treatment is 110°C to 130°C. The preparation method as described in claim 1, wherein the two ends of the polymer compatibilizer are respectively connected to the polyamide material dispersed by the polymer dispersant and the carbon fiber. The preparation method as described in claim 1, wherein the polymer compatibilizer has a maleic anhydride functional group, and the total weight of the monomers synthesized to synthesize the polymer compatibilizer is 100 weight percent, and 0.5 weight percent to 1.3 weight percent of the monomers have a maleic anhydride functional group. The preparation method as described in claim 1, wherein the premix further comprises a polyolefin elastomer, and the polyolefin elastomer is synthesized from monomers selected from the following group: ethylene, 1-propylene, 1-butene, 1-hexene and 1-octene. The preparation method as described in claim 8, wherein the polyolefin elastomer is selected from the group consisting of: ethylene/α-olefin random copolymer, ethylene/α-olefin block copolymer, ethylene propylene diene monomer rubber elastomer and ethylene propylene diene monomer rubber elastomer.

Images