Long fiber reinforced polyether-ether-ketone master batch, preparation method thereof and polyaryletherketone composite material

Abstract

The invention relates to the field of composite materials, in particular to a long-fiber-reinforced polyether-ether-ketone master batch, a preparation method thereof and a polyaryletherketone composite material. The preparation method comprises the following steps: firstly, carrying out hydroxylation treatment on sulfonated polyether-ether-ketone, and then carrying out fluorosilane treatment to obtain fluorinated sulfonated polyether-ether-ketone; carrying out surface plasma modification on inorganic long fibers to enable the inorganic long fibers to adsorb the fluorinated sulfonated polyether-ether-ketone to obtain modified inorganic long fibers; adding the polyether-ether-ketone master batch into a main feeding hopper of an extruder, adding the modified inorganic long fibers from a side feeding die orifice in the melt extrusion process, so that the molten polyether-ether-ketone master batch infiltrates the modified inorganic long fibers, and granulating to obtain long fiber reinforced polyether-ether-ketone master batch; the polyether-ether-ketone master batch comprises a base material and an auxiliary agent; the base material is polyether-ether-ketone and heat-resistant resin, and the auxiliary agent comprises alkali metal bicarbonate and alkali metal phosphate; according to the method, the compatibility between the materials can be improved, and the thermal stability and the mechanical property of the obtained composite material are better.

Description

Technical Field

[0001] The invention relates to the field of composite materials, and in particular to a long fiber reinforced polyetheretherketone masterbatch and a preparation method thereof, and a polyaryletherketone composite material. Background Art

[0002] Polyetheretherketone (PEEK) is a semi-crystalline special engineering plastic with a fully aromatic structure. It has excellent mechanical properties, high temperature resistance, corrosion resistance, self-lubrication and other outstanding properties. It is widely used in high-end fields such as aerospace, electronic semiconductors, nuclear industry, and medical equipment. However, with the development of society, people's requirements for material performance are constantly expanding. A single pure PEEK resin is difficult to meet the needs of different fields. Therefore, the modification of PEEK is a necessary means to prepare high-performance composite materials.

[0003] Carbon fiber (CF) has the characteristics of high strength, high modulus, high temperature resistance, creep resistance, etc. After the short-cut carbon fiber is modified with PEEK resin, the tensile strength of PEEK material can be ≥200MPa, and the heat deformation temperature can be ≥300℃, which greatly improves the application field of PEEK material. Short fiber reinforced PEEK composite materials can be prepared and formed using traditional extrusion and injection molding processes, and have the advantages of high production efficiency and the ability to form complex structures. However, for applications in high-end fields such as aerospace, its mechanical strength is still insufficient. The main reason is that the length of short-cut carbon fiber is seriously lost during extrusion granulation, injection molding or extrusion molding, and the retained length of carbon fiber in the product is generally less than 1mm.

[0004] Long fiber reinforced thermoplastic (LFT) is a type of composite material that has developed rapidly in recent years. It is mainly made of glass fiber, carbon fiber, organic fiber, etc., different thermoplastic material matrices and various additives through special equipment and processes. Compared with conventional short fiber reinforced thermoplastics, the fiber length in LFT materials is the same as the length of the particles, and the fibers are continuously and evenly distributed in parallel in the granules, which greatly improves the performance of the products. It has better mechanical and thermal properties than short carbon fiber reinforced plastics, especially the impact strength is significantly improved. At present, the resin matrix with the largest use of LFT reinforcement process at home and abroad is polypropylene PP, followed by polyamide PA. In addition, PBT, ABS, PPS and other resins are also used. However, the long-term use temperature of these resin matrices is not high, which cannot meet the requirements of some fields with harsh use environments. The long-term use temperature of PEEK can reach 250°C. The use of LFT process to enhance PEEK can meet the application in aerospace and other fields. However, there are many bottlenecks in the processing of LFT-PEEK materials: First, PEEK is highly hydrophobic and lacks active functional groups, making it difficult to form chemical bonds between the reinforcing fibers and the PEEK resin, which in turn leads to unsatisfactory performance of the interface layer between the reinforcing fibers and the PEEK resin; second, the processing temperature of PEEK material is relatively high (360-420°C) and the viscosity is relatively high. Its fluidity is still poor within its processing temperature range, resulting in poor fiber impregnation effect, which significantly reduces product performance; third, PEEK material is almost insoluble in any solvent other than concentrated sulfuric acid, and cannot be processed by solution impregnation.

[0005] In summary, how to improve the retention length of carbon fiber in PEEK composites and the interfacial bonding strength between PEEK resin and carbon fiber is of great significance for expanding the application of PEEK composites in aerospace and other fields. Summary of the invention

[0006] In order to solve the above technical problems, a long fiber reinforced polyetheretherketone masterbatch and a preparation method thereof, and a polyaryletherketone composite material are provided. The present invention performs hydroxylation modification on sulfonated polyetheretherketone, and then performs fluorination modification to obtain fluorinated sulfonated polyetheretherketone, thereby performing surface modification on inorganic fibers to obtain a long fiber reinforced polyetheretherketone masterbatch, which can form an effective bond between polyaryletherketone and inorganic fibers, improve the interface bonding force, and optimize the mechanical properties of the composite material.

[0007] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0008] A method for preparing long fiber reinforced polyetheretherketone masterbatch comprises the following steps:

[0009] S1, subjecting the sulfonated polyetheretherketone to hydroxylation to obtain hydroxylated sulfonated polyetheretherketone, and then subjecting the hydroxylated sulfonated polyetheretherketone to fluorosilane treatment to obtain fluorinated sulfonated polyetheretherketone;

[0010] S2, after surface plasma modification of the inorganic long fiber, the inorganic long fiber is adsorbed with the fluorinated sulfonated polyetheretherketone to obtain a modified inorganic long fiber;

[0011] S3, adding the polyetheretherketone masterbatch into the main feeding hopper of the extruder, and during the melt extrusion process, adding the modified inorganic long fiber from the side feeding die, so that the molten polyetheretherketone masterbatch infiltrates the modified inorganic long fiber, and granulating to obtain the long fiber reinforced polyetheretherketone masterbatch;

[0012] The polyetheretherketone masterbatch comprises a base material and an auxiliary agent;

[0013] The base material, calculated on a basis of 100 parts by weight, comprises polyetheretherketone and a heat-resistant resin in a mass ratio of 5-20:80-95, and the auxiliary agent comprises alkali metal bicarbonate and alkali metal phosphate;

[0014] The amount of the alkali metal bicarbonate is 0.1%-1% (preferably 0.1%-0.3%) of the base material, and the amount of the alkali metal phosphate is 0.1%-1% (preferably 0.1%-0.5%) of the base material;

[0015] The inorganic long fibers in the long fiber reinforced polyetheretherketone masterbatch account for 20-50wt%, and the fiber content in the masterbatch is adjusted by feeding rate, main engine speed, etc.

[0016] Furthermore, the sulfonation degree of the sulfonated polyetheretherketone is at least 30% and the particle size of the material is less than 50 microns;

[0017] The heat-resistant resin is selected from one or more of polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), and polyether sulfone (PES);

[0018] The inorganic long fiber is selected from one of carbon fiber, glass fiber, basalt fiber, boron fiber, ceramic fiber and metal fiber, and is a continuous fiber;

[0019] The alkali metal bicarbonate is selected from one or more of sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, and cesium bicarbonate. The alkali metal bicarbonate is used as a compatibilizer to improve the compatibility between the long fiber and polyetheretherketone; the alkali metal phosphate is selected from one or more of sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate, sodium polymetaphosphate, and potassium polymetaphosphate. The alkali metal phosphate can improve the processing characteristics of polyetheretherketone and reduce the viscosity of polyetheretherketone during processing; alkali metals and alkali metal phosphates produce thermal decomposition during the melting process to form sodium carbonate, potassium carbonate, sodium metaphosphate, etc., which can improve the compatibility between the fiber and polyetheretherketone and improve the material strength on the one hand, and can be used as flame retardants and heat stabilizers on the other hand to improve the fire resistance and heat resistance of the material;

[0020] The masterbatch may also include functional additives such as thermally conductive fillers, electrically conductive fillers, absorbing materials, antistatic materials, internal and external lubricants (such as polysiloxanes, ethylene stearamides, long-chain unsaturated fatty acid salts, etc.) and the like, which may be added as needed.

[0021] Furthermore, the hydroxylation process is as follows: immersing the sulfonated polyetheretherketone in an isopropanol solution containing sodium borohydride NaBH4, followed by washing and drying to obtain hydroxylated sulfonated polyetheretherketone. Sodium borohydride can be dissolved evenly in hot isopropanol, and it is noted that the solvent and the container cannot contain water.

[0022] Furthermore, the mass ratio of the sodium borohydride to the isopropanol is 1:4-10; the mass ratio of the sulfonated polyetheretherketone to the sodium borohydride is 1:0.5-2, and the sodium borohydride can reduce the ketone in the molecule to a hydroxyl group;

[0023] The temperature of the hydroxylation treatment is 10-25° C., the treatment time is 2-8 hours, and stirring is performed during the treatment.

[0024] Furthermore, the fluorosilane treatment process is: placing the fluorosilane and the hydroxylated sulfonated polyetheretherketone in an alcohol solvent and stirring, adjusting the system to acidity for fluorination treatment, and washing and drying to obtain the fluorinated sulfonated polyetheretherketone.

[0025] Further, the fluorosilane is selected from one or more of 3,3,3-trifluoropropylmethyldimethoxysilane, trimethoxy (3,3,3-trifluoropropyl) silane, 3-trifluoroacetoxypropyltrimethoxysilane, pentafluorophenylpropyltrimethoxysilane, pentafluorophenyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, and methyl (3,3,3-trifluoropropyl) diethoxysilane;

[0026] Specifically, the fluorosilane, the hydroxylated sulfonated polyetheretherketone and the alcohol solvent are stirred at room temperature in the following ratio: 0.1-1g: 1g: 20-80mL, and then acetic acid is added dropwise to adjust the pH value of the system to below 5 for fluorination treatment for 1-3h.

[0027] Furthermore, before the surface plasma modification treatment, the original sizing agent on the surface of the inorganic long fiber needs to be baked at a temperature of 200-500° C.; the surface plasma modification uses a mixture of two of oxygen, air and nitrogen, with a power of 300-3000W and a treatment time of 10 seconds to 150 seconds;

[0028] Furthermore, the process of making the inorganic long fibers that have been baked and surface plasma modified adsorb the fluorinated sulfonated polyetheretherketone is: immersing the treated inorganic long fibers in water, adding the fluorinated sulfonated polyetheretherketone and simultaneously performing ultrasonic treatment and heat treatment, the heating treatment temperature is 60-280°C, and the treatment time is at least 1 hour; the attachment amount of the fluorinated sulfonated polyetheretherketone on the inorganic long fibers is 10wt%-30wt%.

[0029] Furthermore, during the melt extrusion process, the temperature of each zone of the extruder is 280-380° C., and the main engine speed is 100-400 rpm.

[0030] Another aspect of the present invention provides long fiber reinforced polyetheretherketone masterbatch obtained by the above preparation method.

[0031] The third aspect of the present invention provides a polyaryletherketone composite material, comprising the long fiber reinforced polyetheretherketone masterbatch prepared by the above method, and polyaryletherketone;

[0032] The long fiber reinforced polyetheretherketone masterbatch accounts for at least 5% of the composite material.

[0033] Beneficial technical effects: The strength of continuous fiber LFT reinforced PEEK material is significantly higher than that of ordinary short fiber SCF reinforced PEEK material, but due to the high viscosity of the PEEK material itself, it cannot wet the long continuous fiber and is not suitable for the LFT process. In order to solve the above problems, the present invention uses a large amount of heat-resistant resins such as PPS and PPSU with low viscosity and a small amount of PEEK and a synergistic additive to first prepare LFT masterbatch, which can be directly mixed with polyetheretherketone in any proportion for injection molding during molding. In this process, the compatibility between the heat-resistant resin, polyetheretherketone and carbon fiber must be ensured. Therefore, the sizing process of the carbon fiber adopts the method of removing the original sizing agent on its surface and then re-sizing it. The re-sizing agent adopts fluorinated sulfonated polyetheretherketone. SPEEK is first hydroxylated to convert part of the ketones in the molecular structure into hydroxyl groups, and then fluorinated to graft fluorosilane at the hydroxyl group. In this way, a part of fluorosilane exists in the molecular structure of SPEEK, so that it has a good interface bonding effect with the carbon fiber treated with plasma, and the compatibility of the carbon fiber in polyetheretherketone and heat-resistant resin is improved. At the same time, alkali metal bicarbonate and alkali metal hydrogen phosphate are decomposed into carbonate and pyrophosphate during the melting process, which further improves the compatibility between materials and improves the thermal stability of the composite material.

[0034] The present invention uses the LFT molding process to compound a heat-resistant resin with a viscosity much lower than that of the PEEK material with modified fibers to obtain a long fiber reinforced masterbatch, and then the masterbatch and the PEEK resin are injection molded by physical blending, thereby avoiding the problem that the PEEK material is difficult to mold by the LFT process and retaining the fiber length in the composite material. The obtained material has the characteristics of high temperature resistance and high mechanical strength.

[0035] The process of the present invention can prevent the cross-linking or degradation of the resin during the high-temperature melting process, and also improves the compatibility of PEEK resin with resins such as PPS and PES, thereby ensuring the excellent performance of the material. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0037] Unless otherwise specifically stated, the numerical value set forth in these embodiments does not limit the scope of the present invention. The technology and method known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology and method should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values.

[0038] The experimental methods in the following examples without specifying specific conditions are usually measured in accordance with national standards; if there is no corresponding national standard, the method is carried out in accordance with the general standard requirements or general methods.

[0039] The sulfonated polyetheretherketone SPEEK used below is provided by Shandong Junhao High Performance Polymer Co., Ltd., with a sulfonation degree of 20%-50% and a particle size of 50-150 μm.

[0040] Example 1

[0041] A method for preparing long fiber reinforced polyetheretherketone masterbatch comprises the following steps:

[0042] S1. Under stirring, 500 g of sulfonated polyetheretherketone was mixed with an isopropanol solution containing sodium borohydride (250 g of sodium borohydride and 1650 g of isopropanol), and hydroxylated at 15° C. After reacting for 5 h, the mixture was taken out, washed and dried to obtain hydroxylated sulfonated polyetheretherketone;

[0043] Weigh 250g of hydroxylated sulfonated polyetheretherketone and place it in 12.5L of anhydrous ethanol and stir it with 50g of trimethoxy(3,3,3-trifluoropropyl)silane, adjust the system to pH=4.5 for fluorination treatment, wash and dry to obtain fluorinated sulfonated polyetheretherketone for standby use;

[0044] S2, 500g of carbon fiber (continuous fiber) was first baked at a high temperature of 400°C to remove the original sizing agent; then it was flattened and entered into a plasma device for surface plasma modification, the plasma generating gas was air, the plasma instrument power was 600W, and the modification time was 60 seconds; then it was immersed in a water tank filled with water, 250g of the above-mentioned S1 fluorinated sulfonated polyetheretherketone was added, and ultrasonic treatment (ultrasonic power 1000W) and heating treatment at 150°C for 3h were performed at the same time, filtered out and dried, and 648g of modified carbon fiber was obtained by weighing (wherein the adhesion amount of fluorinated sulfonated polyetheretherketone on the modified carbon fiber accounted for about 22.8%);

[0045] S3, prepare polyetheretherketone masterbatch: 50g PEEK, 450g PPS, 0.5g sodium bicarbonate, 1g sodium dihydrogen phosphate, 0.5g pentaerythritol stearate, mix well and set aside;

[0046] The above-mentioned polyetheretherketone masterbatch is added to the main feeding hopper of the extruder, melt-extruded at 365°C, and the main engine speed is 300rpm. During the melt extrusion process, 500g of the treated modified continuous carbon fiber is passed through the side cavity die head and then passed through the molten high-temperature resistant thermoplastic resin to make the molten polyetheretherketone masterbatch impregnate the modified fiber. After water cooling, pelletizing and drying, long carbon fiber reinforced polyetheretherketone masterbatch is obtained. The mass fraction of the modified carbon fiber in the masterbatch is about 41.5%, and the carbon fiber length distribution in the masterbatch is about 15-20mm.

[0047] Preparation of polyetheretherketone composite material: 600 g of the above-mentioned long carbon fiber reinforced polyetheretherketone masterbatch and 400 g of PEEK were mixed evenly, and then injection molded at 360-390° C. (injection mold temperature 200° C.) to obtain a long carbon fiber reinforced polyetheretherketone composite material.

[0048] Example 2

[0049] A method for preparing long fiber reinforced polyetheretherketone masterbatch comprises the following steps:

[0050] S1. Under stirring, 500 g of sulfonated polyetheretherketone was mixed with an isopropanol solution containing sodium borohydride (400 g of sodium borohydride and 1760 g of isopropanol), and hydroxylated at 10° C. After reacting for 2 h, the mixture was taken out, washed and dried to obtain hydroxylated sulfonated polyetheretherketone;

[0051] Weigh 250 g of hydroxylated sulfonated polyetheretherketone and 100 g of 3,3,3-trifluoropropyltriethoxysilane in 15 L of anhydrous ethanol and stir, adjust the system to pH = 4 for fluorination treatment, wash and dry to obtain fluorinated sulfonated polyetheretherketone for standby use;

[0052] S2, 500g of carbon fiber (continuous fiber) was first baked at 450°C to remove the original sizing agent; then it was laid flat and entered into a plasma device for surface plasma modification, the plasma generated gas was air, the plasma instrument power was 1000W, and the modification time was 80 seconds; then it was immersed in a water tank filled with water, 200g of the above-mentioned S1 fluorinated sulfonated polyetheretherketone was added, and ultrasonic treatment (ultrasonic power 1000W) and heating treatment at 180°C for 2h were performed at the same time, filtered out and dried, and 585g of modified carbon fiber was obtained by weighing (wherein the adhesion amount of fluorinated sulfonated polyetheretherketone on the modified carbon fiber accounted for about 14.5%);

[0053] S3, prepare polyetheretherketone masterbatch: 37.5g PEEK, 712.5g PES, 1.5g sodium bicarbonate, 0.8g sodium dihydrogen phosphate, 1g pentaerythritol stearate, mix well and set aside;

[0054] The above-mentioned polyetheretherketone masterbatch is added to the main feeding hopper of the extruder, melt-extruded at 375°C, and the main engine speed is 250rpm. During the melt extrusion process, 500g of the treated modified continuous carbon fiber is passed through the side cavity die head and then passed through the molten high-temperature resistant thermoplastic resin to make the molten polyetheretherketone masterbatch impregnate the modified fiber. After water cooling, pelletizing and drying, long carbon fiber reinforced polyetheretherketone masterbatch is obtained. The mass fraction of the modified carbon fiber in the masterbatch is about 40.2%, and the carbon fiber length distribution in the masterbatch is about 12-15mm.

[0055] Preparation of polyetheretherketone composite material: 500 g of the above-mentioned long carbon fiber reinforced polyetheretherketone masterbatch and 500 g of PEEK were mixed evenly, and then injection molded at 360-390° C. (injection mold temperature 200° C.) to obtain a long carbon fiber reinforced polyetheretherketone composite material.

[0056] Example 3

[0057] A method for preparing long fiber reinforced polyetheretherketone masterbatch comprises the following steps:

[0058] S1. Under stirring, 500 g of sulfonated polyetheretherketone was mixed with an isopropanol solution containing sodium borohydride (325 g of sodium borohydride and 1760 g of isopropanol), and hydroxylated at 10° C. After reacting for 4 h, the mixture was taken out, washed, and dried to obtain hydroxylated sulfonated polyetheretherketone;

[0059] Weigh 250g of hydroxylated sulfonated polyetheretherketone and place it in 18L of anhydrous ethanol with 150g of trimethoxy(3,3,3-trifluoropropyl)silane and stir, adjust the system to pH=5 for fluorination treatment, wash and dry to obtain fluorinated sulfonated polyetheretherketone for standby use;

[0060] S2, 500g of carbon fiber (continuous fiber) was first baked at a high temperature of 500°C to remove the original sizing agent; then it was flattened and entered into a plasma device for surface plasma modification, the plasma generated gas was air, the plasma instrument power was 2000W, and the modification time was 30 seconds; then it was immersed in a water tank filled with water, 300g of the above-mentioned S1 fluorinated sulfonated polyetheretherketone was added, and ultrasonic treatment (ultrasonic power 1000W) and heating treatment at 146°C for 4h were performed at the same time, filtered out and dried, and 663g of modified carbon fiber was obtained by weighing (wherein the amount of fluorinated sulfonated polyetheretherketone attached to the modified carbon fiber accounted for about 24.6%);

[0061] S3, prepare polyetheretherketone masterbatch: 165g PEEK, 935g PPSU, 5.5g sodium bicarbonate, 2.2g sodium dihydrogen phosphate, 5g pentaerythritol stearate, mix well and set aside;

[0062] The above-mentioned polyetheretherketone masterbatch is added to the main feeding hopper of the extruder, melt-extruded at 385°C, and the main engine speed is 400rpm. During the melt extrusion process, 500g of the treated modified continuous carbon fiber is passed through the side cavity die head and then passed through the molten high-temperature resistant thermoplastic resin to make the molten polyetheretherketone masterbatch impregnate the modified fiber. After water cooling, pelletizing and drying, long carbon fiber reinforced polyetheretherketone masterbatch is obtained. The mass fraction of the modified carbon fiber in the masterbatch is about 39.7%, and the carbon fiber length distribution in the masterbatch is about 12-15mm.

[0063] Preparation of polyetheretherketone composite material: 200 g of the above-mentioned long carbon fiber reinforced polyetheretherketone masterbatch and 800 g of PEEK were mixed evenly, and then injection molded at 360-390° C. (injection mold temperature 200° C.) to obtain a long carbon fiber reinforced polyetheretherketone composite material.

[0064] Comparative Example 1

[0065] The preparation process of the masterbatch and the composite material in this case is the same as that in Example 1, except that S1 does not exist, and sulfonated polyetheretherketone is used in S2 instead of fluorinated sulfonated polyetheretherketone for sizing, and the adhesion amount of sulfonated polyetheretherketone on the modified carbon fiber is controlled to account for 25wt%.

[0066] Comparative Example 2

[0067] The preparation process of the masterbatch and the composite material in this case is the same as that in Example 1, except that S1 does not exist, and after the carbon fiber is baked and surface plasma modified in S2, 50 g of trimethoxy (3,3,3-trifluoropropyl) silane is added to the water, and ultrasonic and heating treatment are performed at the same time (the conditions are the same as in Example 1).

[0068] Comparative Example 3

[0069] The preparation process of the masterbatch and composite material in this case is the same as that in Example 1, except that there is no PPS in S3, and 500g is all PEEK.

[0070] Comparative Example 4

[0071] The preparation process of the masterbatch and the composite material in this case is the same as that in Example 1, except that 1.5 g of sodium carbonate is used in S3 to replace sodium bicarbonate and sodium dihydrogen phosphate.

[0072] The performance of the composite materials in the above cases was tested, and the results are shown in Table 1.

[0073]

[0074] As shown in Table 1, Comparative Examples 1 and 2 use sulfonated polyetheretherketone as a sizing agent and a silane coupling agent to treat carbon fiber, respectively, and the mechanical properties of the obtained composite materials are better than that of the composite material using fluorinated sulfonated polyetheretherketone as a sizing agent in Example 1. The present invention uses a large amount of heat-resistant resins such as PPS and PPSU with low viscosity and a small amount of PEEK, fluorinated sulfonated polyetheretherketone as a sizing agent, and bicarbonate and phosphate to first prepare LFT masterbatch, which can be directly mixed with polyetheretherketone in any proportion for injection molding during molding to obtain a composite material with better mechanical properties. In order to ensure the compatibility between the heat-resistant resin, polyetheretherketone and carbon fiber, the sizing process of the carbon fiber of the present invention adopts the method of removing the original sizing agent on the surface of the carbon fiber and then re-sizing it. The re-sizing agent adopts fluorinated sulfonated polyetheretherketone. SPEEK is firstly subjected to hydroxylation treatment to convert part of the ketones in the molecular structure into hydroxyl groups, and then subjected to fluorination treatment to graft fluorosilane at the hydroxyl groups. In this way, a part of fluorosilane exists in the molecular structure of SPEEK, so that it has a good interface bonding effect with the carbon fiber treated with plasma, and the compatibility of the carbon fiber in polyetheretherketone and heat-resistant resin is improved. At the same time, alkali metal bicarbonate and alkali metal hydrogen phosphate are decomposed into carbonate and pyrophosphate during the melting process, which further improves the compatibility between materials and improves the thermal stability of the composite material, so that the mechanical properties of the composite material of the embodiment of the present invention are better.

[0075] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a long fiber reinforced polyetheretherketone masterbatch, characterized in that: The steps include: S1, subjecting the sulfonated polyetheretherketone to hydroxylation to obtain hydroxylated sulfonated polyetheretherketone, and then subjecting the hydroxylated sulfonated polyetheretherketone to fluorosilane treatment to obtain fluorinated sulfonated polyetheretherketone; S2, after surface plasma modification of the inorganic long fiber, the inorganic long fiber is adsorbed with the fluorinated sulfonated polyetheretherketone to obtain a modified inorganic long fiber; S3, adding the polyetheretherketone masterbatch into the main feeding hopper of the extruder, and during the melt extrusion process, adding the modified inorganic long fiber from the side feeding die, so that the molten polyetheretherketone masterbatch infiltrates the modified inorganic long fiber, and granulating to obtain the long fiber reinforced polyetheretherketone masterbatch; The polyetheretherketone masterbatch comprises a base material and an auxiliary agent; The base material, calculated on a basis of 100 parts by weight, comprises polyetheretherketone and a heat-resistant resin in a mass ratio of 5-20:80-95, and the auxiliary agent comprises alkali metal bicarbonate and alkali metal phosphate; The amount of the alkali metal bicarbonate is 0.1%-1% of the base material, and the amount of the alkali metal phosphate is 0.1%-1% of the base material; The inorganic long fibers in the long fiber reinforced polyetheretherketone masterbatch account for 20-50wt%.

2. The method for preparing a long fiber reinforced polyetheretherketone masterbatch according to claim 1, characterized in that: The sulfonation degree of the sulfonated polyetheretherketone is at least 30% and the particle size of the material is less than 50 microns; The heat-resistant resin is selected from one or more of polyphenylene sulfide PPS, polyphenylene sulfone PPSU, and polyether sulfone PES; The inorganic long fiber is selected from one of carbon fiber, glass fiber, basalt fiber, boron fiber, ceramic fiber and metal fiber, and is a continuous fiber; The alkali metal bicarbonate is selected from one or more of sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, and cesium bicarbonate; The alkali metal phosphate is selected from one or more of sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate, sodium polymetaphosphate, and potassium polymetaphosphate.

3. The method for preparing a long fiber reinforced polyetheretherketone masterbatch according to claim 1, characterized in that: The process of the hydroxylation treatment is: immersing the sulfonated polyetheretherketone in an isopropanol DMSO solution containing sodium borohydride, followed by washing and drying to obtain the hydroxylated sulfonated polyetheretherketone.

4. The method for preparing a long fiber reinforced polyetheretherketone masterbatch according to claim 3, characterized in that: The mass ratio of the sodium borohydride to the isopropanol is 1:4-10; the mass ratio of the sulfonated polyetheretherketone to the sodium borohydride is 1:0.5-2; The temperature of the hydroxylation treatment is 20-40° C., the treatment time is 2-8 hours, and stirring is performed during the treatment.

5. The method for preparing a long fiber reinforced polyetheretherketone masterbatch according to claim 1, characterized in that: The fluorosilane treatment process is: placing the fluorosilane and the hydroxylated sulfonated polyetheretherketone in an alcohol solvent and stirring, adjusting the system to acidity for fluorination treatment, washing and drying to obtain the fluorinated sulfonated polyetheretherketone; The fluorosilane is selected from one or more of 3,3,3-trifluoropropylmethyldimethoxysilane, trimethoxy(3,3,3-trifluoropropyl)silane, 3-trifluoroacetoxypropyltrimethoxysilane, pentafluorophenylpropyltrimethoxysilane, pentafluorophenyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane and methyl(3,3,3-trifluoropropyl)diethoxysilane.

6. The method for preparing a long fiber reinforced polyetheretherketone masterbatch according to claim 5, characterized in that: The fluorosilane, the hydroxylated sulfonated polyetheretherketone and the alcohol solvent are stirred at room temperature in the following ratio: 0.1-1 g: 1 g: 20-80 mL, and then acetic acid is added dropwise to adjust the pH value of the system to below 5 for fluorination treatment for 1-3 hours.

7. The method for preparing a long fiber reinforced polyetheretherketone masterbatch according to claim 1, characterized in that: Before the surface plasma modification treatment, the original sizing agent on the surface of the inorganic long fiber needs to be baked at a temperature of 200-500° C.; The surface plasma modification uses a mixture of two of oxygen, air and nitrogen, with a power of 300-3000W and a treatment time of 10 seconds to 150 seconds; During the melt extrusion process, the temperature of each zone of the extruder is 280-380° C., and the main engine speed is 100-400 rpm.

8. The method for preparing a long fiber reinforced polyetheretherketone masterbatch according to claim 7, characterized in that: The process of making the inorganic long fibers that have been baked and surface plasma modified adsorb the fluorinated sulfonated polyetheretherketone is: immersing the treated inorganic long fibers in water, adding the fluorinated sulfonated polyetheretherketone and simultaneously performing ultrasonic treatment and heating treatment, the heating treatment temperature is 60-280°C, and the treatment time is at least 1 hour; the attachment amount of the fluorinated sulfonated polyetheretherketone on the inorganic long fibers is 10wt%-30wt%.

9. The long fiber reinforced polyetheretherketone masterbatch obtained according to the preparation method according to any one of claims 1 to 8.

10. A polyaryletherketone composite material, characterized in that: Comprising a long fiber reinforced polyetheretherketone masterbatch obtained by the preparation method according to any one of claims 1 to 8, and polyaryletherketone; The long fiber reinforced polyetheretherketone masterbatch accounts for at least 5% of the composite material.

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