Glass fiber reinforced PEEK composite material and preparation method thereof

Abstract

The invention discloses a glass fiber reinforced PEEK composite material and a preparation method thereof. The material comprises the following components in percentage by mass: 60%-80% of PEEK resin, 20%-35% of chopped glass fiber, 1%-5% of a hyperbranched polyaryletherketone copolymer, 0.5%-2% of a silane coupling agent, 0.2%-1% of an antioxidant and 1%-3% of a lubricant. By adding the hyperbranched polyaryletherketone copolymer (the number-average molecular weight is 5000-20000, and the branching degree is 0.6-0.8), cooperating with the silane coupling agent and optimizing the process, the bending fatigue life of the prepared GF / PEEK composite material is larger than or equal to 2.1 * 10 times, the tensile strength is larger than or equal to 158 MPa, the bending modulus is larger than or equal to 8.5 GPa, and the comprehensive performance is excellent; different functional formulas (wear resistance, high rigidity and heat conduction) can meet the requirements of specific scenes.

Description

Technical Field

[0001] This invention relates to the field of PEEK materials, and more specifically, to a glass fiber reinforced PEEK composite material and its preparation method. Background Technology

[0002] Polyetheretherketone (PEEK), as a high-performance specialty engineering plastic, possesses excellent high-temperature resistance (long-term operating temperature above 250℃), chemical corrosion resistance, high mechanical strength, and biocompatibility, making it irreplaceable in high-end manufacturing fields. To further enhance its strength, rigidity, and dimensional stability, the industry commonly uses glass fiber (GF) for reinforcement modification, forming glass fiber reinforced PEEK (GF / PEEK) composite materials.

[0003] However, existing GF / PEEK composites suffer from a core technical challenge: the PEEK matrix is ​​a non-polar semi-crystalline polymer, while the glass fiber surface contains polar hydroxyl groups, resulting in poor interfacial compatibility and weak fiber-matrix bonding. Traditional solutions primarily rely on silane coupling agents (such as KH-550 and KH-602) for surface treatment of the glass fibers. However, these coupling agents can only connect the fibers and matrix through physical adsorption or weak chemical interactions, limiting interfacial bond strength. Under long-term dynamic loads, microcracks easily form at the interface, leading to fiber debonding and pull-out, ultimately resulting in insufficient flexural fatigue performance of the composite material. GF / PEEK composites prepared using existing technologies typically exhibit a flexural fatigue life ≤10 seconds under flexural stress of 80 MPa and frequency of 10 Hz. 7 Secondly, the tensile strength is ≤120MPa and the flexural modulus is ≤6GPa, which is insufficient to meet the long-term use requirements of core components such as aircraft engine brackets and medical device joint components.

[0004] In addition, some existing technologies attempt to add common copolymers as compatibilizers, but these compatibilizers have low matching degree with the PEEK matrix structure, poor dispersibility, and are prone to agglomeration. This not only fails to effectively improve interfacial bonding but may also degrade the mechanical properties of the material. At the same time, PEEK melt viscosity is high, and traditional formulations have insufficient fluidity during processing, which can easily lead to equipment wear and product molding defects (such as material shortage and air bubbles), further limiting its application range. Summary of the Invention

[0005] The purpose of this invention is to provide a glass fiber reinforced PEEK composite material and its preparation method, so as to solve the technical problems existing in the background art.

[0006] This invention provides a glass fiber reinforced PEEK composite material, comprising the following components by weight percentage: 60%-80% PEEK resin, 20%-35% chopped glass fiber, 1%-5% hyperbranched polyaryletherketone copolymer, 0.5%-2% silane coupling agent, 0.2%-1% antioxidant, and 1%-3% lubricant; the composite material exhibits a bending fatigue life ≥2×10⁻⁶ under bending stress of 80 MPa and frequency of 10 Hz. 7 Tensile strength ≥150MPa, flexural modulus ≥8GPa.

[0007] In a preferred embodiment, the PEEK resin is a powder with a particle size of 10-50 μm, and its moisture content is ≤0.02% after drying before processing.

[0008] In a preferred embodiment, the chopped glass fiber has a length of 3-5 mm and its surface is pretreated with a silane coupling agent, wherein the silane coupling agent is KH-602 or KH-550.

[0009] In a preferred embodiment, the hyperbranched polyaryletherketone copolymer has a number average molecular weight of 5,000-20,000 and a branching degree of 0.6-0.8. Its terminal hydroxyl groups form hydrogen bonds with the PEEK matrix, and the terminal aromatic rings react chemically with the hydroxyl groups on the glass fiber surface.

[0010] In a preferred embodiment, the antioxidant is a compound of antioxidants 168 and 1098 or antioxidant S-9228; the lubricant is polytetrafluoroethylene, and its mass percentage is adjusted to 10% when it is necessary to improve wear resistance.

[0011] A method for preparing a glass fiber reinforced PEEK composite material includes the following steps:

[0012] S1, Raw material pretreatment: Dry PEEK resin at 140-160℃ for 4-8 hours, and control the moisture content to ≤0.02%; Soak chopped glass fibers in a 1% (w / w) silane coupling agent aqueous solution for 30 minutes, and then dry them at 120℃ for 2 hours.

[0013] S1, Premix: Add the dried PEEK resin, hyperbranched polyaryletherketone copolymer, antioxidant and lubricant to a high-speed mixer in proportion, and mix for 10-20 minutes at 80℃ and 700-900r / min to obtain the premix.

[0014] S2, Melt Blending Extrusion: The premixed material is added through the main feed port of the twin-screw extruder, and the pretreated chopped glass fiber is added through the side feed port. The temperature of each zone of the extruder is controlled as follows: Zone 1 335-350℃, Zones 2 to 4 360-390℃, Zones 5 to 8 360-380℃, and the die head 355-380℃. The screw speed is 180-220 r / min, the melt pressure is 15-20 MPa, and the extruded strip is granulated after cooling.

[0015] S3, Post-treatment: Dry the pelletized particles at 110-130℃ for 3-5 hours to obtain glass fiber reinforced PEEK composite particles.

[0016] In a preferred embodiment, the drying temperature of the PEEK resin in S1 is 150°C and the drying time is 6 hours; the silane coupling agent for the chopped glass fiber is KH-602.

[0017] In a preferred embodiment, the high-speed mixer in S2 rotates at 800 r / min and the mixing time is 15 minutes to ensure that the hyperbranched polyaryletherketone copolymer is uniformly dispersed in the PEEK resin.

[0018] In a preferred embodiment, the length-to-diameter ratio of the twin-screw extruder in S3 is 40:1, the temperature fluctuation in each zone is ≤±5℃, and the screw speed does not exceed 250r / min, ensuring that the glass fiber retains a length ≥1mm in the composite material.

[0019] In a preferred embodiment, the material strip cooling method in S3 is water cooling, with the cooling water temperature controlled at 20-30℃; the pellet length is 2-4mm; the post-treatment drying temperature is 120℃; and the drying time is 4 hours.

[0020] The beneficial effects of the technical solution of this invention are:

[0021] This invention, through the addition of hyperbranched polyaryletherketone copolymers (number average molecular weight 5000-20000, branching degree 0.6-0.8), combined with silane coupling agents and optimized processes, produces GF / PEEK composite materials with a flexural fatigue life ≥2.1×10⁻⁶. 7 It has excellent overall performance with tensile strength ≥158MPa and flexural modulus ≥8.5GPa; different functional formulations (wear-resistant, high rigidity, thermal conductivity) can meet the needs of specific scenarios.

[0022] Compared with Comparative Example 1 (without special compatibilizer) and Comparative Example 2 (with ordinary compatibilizer), the hyperbranched polyaryletherketone copolymer of the present invention can form hydrogen bonds with the PEEK matrix through terminal hydroxyl groups and chemically react with the terminal aromatic rings with the hydroxyl groups on the glass fiber surface, which significantly improves the interfacial bonding strength (87.5% higher than Comparative Example 1 and 43.9% higher than Comparative Example 2), thereby greatly optimizing the bending fatigue performance and mechanical strength. At the same time, the special compatibilizer has good compatibility with PEEK, which can improve the processing fluidity and solve the molding problems of traditional formulations. Detailed Implementation

[0023] The present invention will now be described in further detail. The embodiments of the invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

[0024] The raw materials used in the examples and comparative examples are as follows:

[0025] PEEK resin: 20μm particle size, commercially available; chopped glass fiber: 4mm length, commercially available; hyperbranched polyaryletherketone copolymer: number average molecular weight 12000, branching degree 0.7, self-made; silane coupling agent: KH-602, KH-550, commercially available; antioxidant: 168 and 1098 compound (mass ratio 1:1), S-9228, commercially available; lubricant: polytetrafluoroethylene (PTFE), 5μm particle size, commercially available; carbon nanotubes: diameter 10-20nm, length 5-10μm, commercially available; nano SiO2: 50nm particle size, commercially available; common compatibilizer: conventional polyaryletherketone copolymer, number average molecular weight 3000, branching degree 0.3, commercially available.

[0026] Example 1 (General Enhanced Version)

[0027] 1. Formulation components (by weight)

[0028] The composition consists of 70% PEEK resin, 28% chopped glass fiber, 3% hyperbranched polyaryletherketone copolymer, 21% silane coupling agent KH-60, 0.5% antioxidant 168 / 1098 compound, and 1.5% PTFE.

[0029] 2. Preparation steps

[0030] Raw material pretreatment: PEEK resin was dried at 150℃ for 6 hours, with a moisture content of 0.015%; chopped glass fibers were soaked in a 1% KH-602 aqueous solution for 30 minutes and dried at 120℃ for 2 hours.

[0031] Premix: Add the above raw materials to a high-speed mixer and mix at 80°C and 800 r / min for 15 minutes to obtain a premix;

[0032] Melt blending extrusion: Twin-screw extruder with a length-to-diameter ratio of 40:1; premixed material is added at the main feed port, and glass fiber is added at the side feed port; extruder zone temperatures: Zone 1 340℃, Zone 2 365℃, Zone 3 375℃, Zone 4 380℃, Zone 5 380℃, Zone 6 370℃, Zone 7 370℃, Zone 8 370℃, die head 380℃; screw speed 200 r / min, melt pressure 18 MPa; the strip is cooled by water cooling at 25℃ and then pelletized (3 mm in length).

[0033] Post-treatment: The particles were dried at 120°C for 4 hours to obtain composite material particles.

[0034] Example 2 (High Abrasion Resistance Type)

[0035] 1. Formulation components (by weight)

[0036] The composition is as follows: 65% PEEK resin, 23% chopped glass fiber, 3% hyperbranched polyaryletherketone copolymer, 1% silane coupling agent KH-550, 0.5% antioxidant S-9228, 10% PTFE, and 2.5% carbon nanotubes.

[0037] 2. Preparation steps

[0038] Raw material pretreatment: PEEK resin was dried at 145℃ for 7 hours, with a moisture content of 0.018%; chopped glass fibers were soaked in a 1% KH-550 aqueous solution for 30 minutes and dried at 120℃ for 2 hours.

[0039] Premix: Add the raw materials to a high-speed mixer and mix at 80°C and 850 r / min for 18 minutes to obtain a premix.

[0040] Melt blending extrusion: Twin-screw extruder zone temperatures: Zone 1 345℃, Zone 2 370℃, Zone 3 380℃, Zone 4 385℃, Zone 5 380℃, Zone 6 370℃, Zone 7 370℃, Zone 8 370℃, Die head 375℃; Screw speed 190 r / min, melt pressure 17 MPa; The feed strip is cooled by water cooling at 28℃ and then pelletized (length 2.5 mm).

[0041] Post-treatment: The particles were dried at 125°C for 3.5 hours to obtain composite material particles.

[0042] Example 3 (High Rigidity Type)

[0043] 1. Formulation components (by weight)

[0044] The composition consists of 60% PEEK resin, 35% chopped glass fiber, 2% hyperbranched polyaryletherketone copolymer, 2% silane coupling agent KH-602, 0.5% antioxidant 168 / 1098 compound, and 1.5% PTFE.

[0045] 2. Preparation steps

[0046] Raw material pretreatment: PEEK resin was dried at 155℃ for 5 hours, with a moisture content of 0.012%; chopped glass fibers were soaked in a 1% KH-602 aqueous solution for 30 minutes and dried at 120℃ for 2 hours.

[0047] Premix: Add the raw materials to a high-speed mixer and mix at 80°C and 900 r / min for 12 minutes to obtain a premix.

[0048] Melt blending extrusion: Twin-screw extruder zone temperatures: Zone 1 335℃, Zone 2 360℃, Zone 3 370℃, Zone 4 380℃, Zone 5 380℃, Zone 6 370℃, Zone 7 370℃, Zone 8 370℃, Die head 365℃; Screw speed 210 r / min, melt pressure 19 MPa; The feed strip is cooled by water at 22℃ and then pelletized (length 3.5 mm).

[0049] Post-treatment: The particles were dried at 115℃ for 4.5 hours to obtain composite material particles.

[0050] Example 4 (thermally conductive functional type)

[0051] 1. Formulation components (by weight)

[0052] The composition is as follows: 62% PEEK resin, 25% chopped glass fiber, 3% hyperbranched polyaryletherketone copolymer, 21% silane coupling agent KH-60, 0.5% antioxidant 168 / 1098 compound, 1.5% PTFE, 5% carbon nanotubes, and 2% nano SiO2.

[0053] 2. Preparation steps

[0054] Raw material pretreatment: PEEK resin was dried at 160℃ for 4 hours with a moisture content of 0.01%; chopped glass fibers were soaked in a 1% KH-602 aqueous solution for 30 minutes and dried at 120℃ for 2 hours.

[0055] Premix: Add the raw materials to a high-speed mixer and mix at 80°C and 750 r / min for 20 minutes to obtain a premix.

[0056] Melt blending extrusion: Twin-screw extruder zone temperatures: Zone 1 348℃, Zone 2 372℃, Zone 3 382℃, Zone 4 388℃, Zone 5 380℃, Zone 6 370℃, Zone 7 370℃, Zone 8 370℃, Die head 378℃; Screw speed 180 r / min, melt pressure 20 MPa; The feed strip is cooled by water cooling at 26℃ and then pelletized (length 2.8 mm).

[0057] Post-treatment: The particles were dried at 130℃ for 3 hours to obtain composite material particles.

[0058] Comparative Example 1 (without hyperbranched polyaryletherketone copolymer)

[0059] Formulation components (mass percentage): PEEK resin 73%, chopped glass fiber 25%, silane coupling agent KH-60 21%, antioxidant 168 / 1098 compound 0.5%, PTFE 1.5%. The preparation steps are exactly the same as in Example 1.

[0060] Comparative Example 2 (with common compatibilizer added)

[0061] Formulation components (mass percentage): PEEK resin 70%, chopped glass fiber 28%, common polyaryletherketone copolymer 3%, silane coupling agent KH-602 1%, antioxidant 168 / 1098 compound 0.5%, PTFE 1.5%. The preparation steps are exactly the same as in Example 1.

[0062] Performance testing

[0063] The materials prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests. The performance test standards are as follows, and the test results are shown in the table below:

[0064] Bending fatigue life: According to GB / T1688-2014, the test conditions are bending stress of 80MPa and frequency of 10Hz.

[0065] Tensile strength: according to GB / T1040.1-2006, tensile rate 5 mm / min;

[0066] Flexural modulus: according to GB / T9341-2008, bending rate 2mm / min;

[0067] Friction coefficient: according to GB / T3960-2016, load 50N, sliding speed 0.5m / s;

[0068] Thermal conductivity: Tested according to GB / T22588-2008, at a temperature of 25℃;

[0069] Interfacial bonding strength: The fiber pull-out test was used to test the bonding strength between the fiber and the matrix.

[0070] Test Project Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 <![CDATA[Flexural fatigue life (×10 7 times)]]> 2.5 2.2 2.1 2.3 0.8 1.2 Tensile strength (MPa) 162 158 175 165 115 130 Flexural modulus (GPa) 8.8 8.5 9.8 9.2 5.6 6.8 Interfacial bond strength (MPa) 28.5 27.8 29.2 28.1 15.2 19.8 Processing fluidity (melt flow rate, 380℃ / 5kg) (g / 10min) 12.5 - - - 8.2 9.5 coefficient of friction - 0.12 - - - - Wear amount (mg / 10000 times) - 0.8 - - - - Thermal conductivity (W / (m・K)) - - - 1.8 - - Heat distortion temperature (°C, 1.8 MPa) - - 215 - - -

[0071] Where: "-" indicates that the item was not tested or that the performance indicator is not a core assessment item for the corresponding sample;

[0072] As shown in Examples 1-4, the GF / PEEK composite material prepared by adding hyperbranched polyaryletherketone copolymer (number average molecular weight 5000-20000, branching degree 0.6-0.8), combined with silane coupling agent and optimized process, has a flexural fatigue life ≥2.1×10⁻⁶. 7 It has excellent overall performance with tensile strength ≥158MPa and flexural modulus ≥8.5GPa; different functional formulations (wear-resistant, high rigidity, thermal conductivity) can meet the needs of specific scenarios.

[0073] Compared with Comparative Example 1 (without special compatibilizer) and Comparative Example 2 (with ordinary compatibilizer), the hyperbranched polyaryletherketone copolymer of the present invention can form hydrogen bonds with the PEEK matrix through terminal hydroxyl groups and chemically react with the terminal aromatic rings with the hydroxyl groups on the glass fiber surface, which significantly improves the interfacial bonding strength (87.5% higher than Comparative Example 1 and 43.9% higher than Comparative Example 2), thereby greatly optimizing the bending fatigue performance and mechanical strength. At the same time, the special compatibilizer has good compatibility with PEEK, which can improve the processing fluidity and solve the molding problems of traditional formulations.

[0074] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A glass fiber reinforced PEEK composite material, characterized in that, It includes the following components by weight percentage: 60%-80% PEEK resin, 20%-35% chopped glass fiber, 1%-5% hyperbranched polyaryletherketone copolymer, 0.5%-2% silane coupling agent, 0.2%-1% antioxidant, and 1%-3% lubricant.

2. The glass fiber reinforced PEEK according to claim 1, characterized in that, The PEEK resin is a powder with a particle size of 10-50μm, and its moisture content is ≤0.02% after drying before processing.

3. The glass fiber reinforced PEEK according to claim 1, characterized in that, The chopped glass fibers are 3-5 mm in length and their surfaces are pretreated with a silane coupling agent, which is KH-602 or KH-550.

4. The glass fiber reinforced PEEK according to claim 1, characterized in that, The hyperbranched polyaryletherketone copolymer has a number average molecular weight of 5,000-20,000 and a branching degree of 0.6-0.

8.

5. The glass fiber reinforced PEEK according to claim 1, characterized in that, The antioxidant is a compound of antioxidants 168 and 1098 or antioxidant S-9228; the lubricant is polytetrafluoroethylene, and its mass percentage is adjusted to 10% when it is necessary to improve wear resistance.

6. A method for preparing a glass fiber reinforced PEEK composite material according to any one of claims 1-5, characterized in that, Includes the following steps: S1, Raw material pretreatment: Dry PEEK resin at 140-160℃ for 4-8 hours, and control the moisture content to ≤0.02%; Soak chopped glass fibers in a 1% (w / w) silane coupling agent aqueous solution for 30 minutes, and then dry them at 120℃ for 2 hours. S1, Premix: Add the dried PEEK resin, hyperbranched polyaryletherketone copolymer, antioxidant and lubricant to a high-speed mixer in proportion, and mix for 10-20 minutes at 80℃ and 700-900r / min to obtain the premix. S2, Melt Blending Extrusion: The premixed material is added through the main feed port of the twin-screw extruder, and the pretreated chopped glass fiber is added through the side feed port. The temperature of each zone of the extruder is controlled as follows: Zone 1 335-350℃, Zones 2 to 4 360-390℃, Zones 5 to 8 360-380℃, and the die head 355-380℃. The screw speed is 180-220 r / min, the melt pressure is 15-20 MPa, and the extruded strip is granulated after cooling. S3, Post-treatment: Dry the pelletized particles at 110-130℃ for 3-5 hours to obtain glass fiber reinforced PEEK composite particles.

7. The method for preparing a glass fiber reinforced PEEK composite material according to claim 6, characterized in that, The drying temperature of PEEK resin in S1 is 150℃, and the drying time is 6 hours; the silane coupling agent for chopped glass fibers is KH-602.

8. The method for preparing a glass fiber reinforced PEEK composite material according to claim 6, characterized in that, The S2 high-speed mixer operates at a speed of 800 r / min and a mixing time of 15 minutes to ensure that the hyperbranched polyaryletherketone copolymer is uniformly dispersed in the PEEK resin.

9. The method for preparing a glass fiber reinforced PEEK composite material according to claim 6, characterized in that, The S3 twin-screw extruder has a length-to-diameter ratio of 40:1, temperature fluctuations in each zone are ≤±5℃, and screw speed does not exceed 250r / min, ensuring that the glass fiber retains a length of ≥1mm in the composite material.

10. The method for preparing a glass fiber reinforced PEEK composite material according to claim 6, characterized in that, The S3 material is cooled by water, with the cooling water temperature controlled at 20-30℃; the pellet length is 2-4mm; the post-processing drying temperature is 120℃; and the drying time is 4 hours.