A composite material and a method for producing the same

Abstract

The application discloses a composite material and a preparation method thereof, realizes preparation of a flat and non-warp sintered sample, and has a series of advantages such as simplicity, high efficiency and low cost. Even if functional fillers such as composite boron nitride, graphite and carbon fiber are used, defects of the sintered sample are not caused. The sintering technology has the advantages of wide adaptability, low cost, simplicity and high efficiency, and can be used for preparation of various high-temperature-resistant resins such as polyaryletherketone and composite materials thereof.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymers and their composites, and relates to a composite material and a preparation method thereof. BACKGROUND

[0002] Polyaryletherketone (PAEK) is a full aromatic thermoplastic special engineering plastic, which has been regarded as a key material for national defense and military industry since it was developed, and is widely used in the fields of aerospace, automobile industry, electronics and electrical appliances, and medical machinery. Phenolphthalein-based polyaryletherketone (PEK-C) is a typical amorphous polymer in PAEK, which has high heat resistance, high strength, high modulus, good dimensional stability, insulation, corrosion resistance, radiation resistance, self-flame retardancy, outstanding anti-fatigue performance, and outstanding tribological performance. However, the melt viscosity of PEK-C is high, and even at high temperature, the flowability of the melt is still poor; meanwhile, the low friction coefficient leads to easy slipping when using a screw extruder. This makes it difficult to use conventional melt processing methods such as extrusion and injection molding to form PEK-C.

[0003] Compared with melt processing, powder sintering is a low-temperature processing technology, which has the following advantages in adjusting the structure and performance of the product: (1) reducing component segregation and organizational segregation, and eliminating coarse and uneven organizational structure; (2) preparing a series of high-performance non-equilibrium materials such as amorphous, microcrystalline, quasi-crystalline, and supersaturated solid solution; (3) producing products with special structures and properties that cannot be produced by ordinary melting, such as new porous biomaterials and porous separation membrane materials. SUMMARY

[0004] The purpose of the present application is to provide a simple and efficient preparation method of polyaryletherketone and its composite material.

[0005] In the present application, quartz sand, polyaryletherketone powder and the like are used as the heat-conducting medium, which is covered on the surface of the green body during sintering to build a uniform temperature field, thereby reducing the temperature difference between the surface and the interior of the material during the heating and cooling process, and preparing a flat and defect-free sintered product.

[0006] According to one aspect of the present application, a preparation method of a composite material is provided, which at least comprises the following steps:

[0007] Mixing raw materials containing a high polymer material and a heat-conducting material, warm-pressing to form a green body, covering a heat-conducting medium on the surface of the green body, and sintering to form the composite material.

[0008] The high polymer material is selected from amorphous phenolphthalein-based polyaryletherketone and / or polyether ether ketone;

[0009] The heat-conducting material is selected from at least one of boron nitride, graphite or carbon fiber;

[0010] The heat-conducting medium is selected from polyaryletherketone powder or quartz sand powder.

[0011] The mass ratio of each substance is: 100 parts of the polymer material, 5-40 parts of the heat-conducting filler.

[0012] The heat-conducting medium completely covers the parison.

[0013] The temperature of the warm compaction is 20-100℃.

[0014] The time of the warm compaction is 0-10h.

[0015] The pressure of the warm compaction is 20-80MPa.

[0016] The temperature of the sintering is 250-320℃.

[0017] The time of the sintering is 1-10h.

[0018] According to another aspect of the present application, a composite material is provided, which is prepared by the above preparation method.

[0019] The tensile strength of the composite material is higher than 90MPa, and the tensile modulus is higher than 2.2GPa.

[0020] The composite material has high flatness and no warping.

[0021] Specifically, the composite material is prepared by the following steps:

[0022] (1) The raw materials are weighed according to the mass ratio: 100 parts of the polymer material, 5-40 parts of the heat-conducting filler; the polymer material is one or both of polyether ether ketone and phenolphthalein-based polyaryletherketone; the heat-conducting filler is one or more of carbon fiber, graphite and boron nitride;

[0023] (2) The composite powder is prepared by mechanical blending;

[0024] (3) The composite powder is transferred to a hot press for warm compaction, the compaction temperature is 20-100℃, and the pressure is 20-80MPa;

[0025] (4) A layer of polyaryletherketone powder or quartz sand powder is covered on the surface of the parison, and then sintering is performed, the sintering temperature is 250-320℃, and the time is 1-10h.

[0026] The present application can produce the following beneficial effects:

[0027] (1) The polymer composite material provided by the present application has high flatness

[0028] (2) The polymer composite material provided by the present application has no warping

[0029] (3) The high polymer composite provided by the application has low cost

[0030] (4) The high polymer composite provided by the application has excellent mechanical properties, and the tensile strength is higher than 90 MPa and the tensile modulus is higher than 2.2 Gpa. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 For powder sintering samples: a, b are sintered samples of Example 6; c, d are sintered samples without adding heat-conducting fillers and heat-conducting mediums. DETAILED DESCRIPTION

[0032] The application will be described in detail below in combination with examples, but the application is not limited to these examples.

[0033] Example 1

[0034] Polyaryletherketone sintered product, 100 parts of amorphous polyaryletherketone, powder is obtained by mechanical blending of a ball mill, and the rotation speed of the ball mill is 600 r / min. Then the powder is warm-pressed into a shape by using a flat vulcanizing machine, the temperature is 20℃, the pressure is 40 MPa, and the time is 10 min. Finally, a layer of amorphous polyaryletherketone powder is covered on the surface of the shape, and the shape is transferred to a sintering furnace for sintering. The sintering temperature is 250℃, and the sintering time is 6 h.

[0035] The structure of the amorphous polyaryletherketone is as follows:

[0036]

[0037] Example 2

[0038] Polyaryletherketone sintered product, 100 parts of amorphous polyaryletherketone and 20 parts of crystalline polyetheretherketone, powder is obtained by mechanical blending of a ball mill, and the rotation speed of the ball mill is 600 r / min. Then the powder is warm-pressed into a shape by using a flat vulcanizing machine, the temperature is 60℃, the pressure is 50 MPa, and the time is 20 min. Finally, a layer of amorphous polyaryletherketone powder is covered on the surface of the shape, and the shape is transferred to a sintering furnace for sintering. The sintering temperature is 280℃, and the sintering time is 8 h.

[0039] The structure of the amorphous polyaryletherketone is as follows:

[0040]

[0041] Example 3

[0042] Polyaryletherketone sintered product, amorphous polyaryletherketone 100 parts, crystalline polyetheretherketone 20 parts, powder is obtained by mechanical blending through a ball mill, the rotation speed of the ball mill is 600 r / min. Then the powder is warm-pressed into a shape using a flat vulcanizing machine, the temperature is 80℃, the pressure is 60 MPa, and the time is 30 min. Finally, a layer of quartz sand powder is covered on the surface of the green body, and the green body is transferred to a sintering furnace for sintering. The sintering temperature is 300℃, and the sintering time is 8h.

[0043] The structure of the amorphous polyaryletherketone is as follows:

[0044]

[0045] Example 4

[0046] Polyaryletherketone composite sintered product, amorphous polyaryletherketone 100 parts, carbon fiber 20 parts, powder is obtained by mechanical blending through a ball mill, the rotation speed of the ball mill is 600 r / min. Then the powder is warm-pressed into a shape using a flat vulcanizing machine, the temperature is 100℃, the pressure is 80 MPa, and the time is 30 min. Finally, a layer of quartz sand powder is covered on the surface of the green body, and the green body is transferred to a sintering furnace for sintering. The sintering temperature is 320℃, and the sintering time is 10h.

[0047] The structure of the amorphous polyaryletherketone is as follows:

[0048]

[0049] Example 5

[0050] Polyaryletherketone composite sintered product, amorphous polyaryletherketone 100 parts, graphite 20 parts, powder is obtained by mechanical blending through a ball mill, the rotation speed of the ball mill is 600 r / min. Then the powder is warm-pressed into a shape using a flat vulcanizing machine, the temperature is 100℃, the pressure is 80 MPa, and the time is 60 min. Finally, a layer of quartz sand powder is covered on the surface of the green body, and the green body is transferred to a sintering furnace for sintering. The sintering temperature is 300℃, and the sintering time is 5h.

[0051] The structure of the amorphous polyaryletherketone is as follows:

[0052]

[0053] Example 6

[0054] Polyaryletherketone composite sintered product, amorphous polyaryletherketone 100 parts, boron nitride 20 parts, powder is obtained by mechanical blending through a ball mill, the rotation speed of the ball mill is 600 r / min. Then the powder is warm-pressed into a shape using a flat vulcanizing machine, the temperature is 60℃, the pressure is 50 MPa, and the time is 30 min. Finally, a layer of quartz sand powder is covered on the surface of the green body, and the green body is transferred to a sintering furnace for sintering. The sintering temperature is 280℃, and the sintering time is 5h.

[0055] The structure of the amorphous polyaryletherketone is as follows:

[0056]

[0057] Figure 1 The powder sintered sample: a, b are sintered samples of Example 6; c, d are sintered samples without adding thermal conductive filler and thermal conductive medium. As can be seen from the figure, the sintered sample of Example 6 of the present application is more flat.

[0058] Test Example

[0059] The present patent relates to the characterization reference standard GB / T1040.2-2006 of tensile strength and tensile modulus. The sample is placed in the clamp. When using the clamp centering pin, for accurate centering, the sample should be slightly tightened before tightening the clamp, and then the clamp is clamped steadily and firmly. To prevent the sample from slipping, a wedge-shaped clamp is used to prevent the sample from moving. The sample is selected as a 1B standard sample with a thickness of 2mm, the test rate is 1mm / min, and each sample is repeated 5 times for testing and the average value is taken.

[0060] The tensile modulus and tensile strength data of Examples 1-6 are shown in Table 1:

[0061] Table 1

[0062] Sample Tensile Modulus (GPa) Tensile Strength (MPa) Example 1 2.2 90 Example 2 3.9 98 Example 3 2.4 101 Example 4 4.2 110 Example 5 3.4 102 Example 6 2.5 95

[0063] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the present application discloses the above as a preferred embodiment, it is not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, which is equivalent to an equivalent embodiment, and belongs to the scope of the technical solution.

Claims

1. A method for preparing a composite material, characterized in that, At least the following steps are included: Raw materials containing polymer materials and thermally conductive materials are mixed, warm-pressed to obtain a preform, a thermally conductive medium is covered on the surface of the preform, and sintered at 250-320℃ to obtain the composite material. The thermally conductive medium is quartz sand powder, and the thermally conductive medium completely encapsulates the preform; The polymer material is selected from amorphous phenolphthalein-based polyaryletherketone and / or polyetheretherketone; The thermally conductive material is selected from at least one of boron nitride, graphite, or carbon fiber; The mass ratio of each substance is: 100 parts of polymer material and 5-40 parts of thermally conductive filler.

2. The preparation method according to claim 1, characterized in that, The temperature for warm pressing is 20~100℃; The pressure for the warm pressing process is 20~80MPa; The warm pressing time is 0 to 10 hours.

3. The preparation method according to claim 1, characterized in that, The sintering time is 1 to 10 hours.

4. A composite material, characterized in that, The composite material is prepared by the preparation method according to any one of claims 1 to 3.

5. The composite material according to claim 4, characterized in that, The composite material has a tensile strength greater than 90 MPa and a tensile modulus greater than 2.2 GPa. The characterization of tensile strength and tensile modulus is referenced to standard GB / T1040.2-2006.

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