Low-melting-point polyaryletherketone-based composite material as well as in-situ synthesis method and application thereof

Abstract

The invention relates to a low-melting-point polyaryletherketone-based composite material as well as an in-situ synthesis method and application thereof, belongs to the technical field of high polymer materials, and particularly relates to a synthesis method of the low-melting-point polyaryletherketone-based composite material, which is particularly suitable for preparing low-melting-point polyaryletherketone-based composite materials of different fillers. The method comprises the following steps: adjusting 1, 2-dichloroethane in reaction materials; the ratio of 4, 4 '-p-hydroxyphenol to 4, 4'-biphenol and the dosage of the catalyst are adjusted, and meanwhile, the reinforcement is added into a reaction system, so that the melting point and the viscosity of the polyaryletherketone material are reduced, and meanwhile, the problems of sedimentation, agglomeration and non-uniform dispersion of the reinforcement in the reaction system in the preparation process of the polyaryletherketone-based composite material are solved. And due to the reduction of the melting point and the viscosity, the forming efficiency of the polyaryletherketone-based composite material is improved, and the cost of 3D printing forming of the polyaryletherketone-based composite material is reduced.

Description

Technical Field

[0001] This invention relates to a low-melting-point polyaryletherketone-based composite material, its in-situ synthesis method, and its application, belonging to the field of polymer materials technology. Specifically, it relates to a method for synthesizing low-melting-point polyaryletherketone-based composite materials, which is particularly suitable for preparing low-melting-point polyaryletherketone-based composite materials with different fillers. Background Technology

[0002] Polyaryletherketone (PAEK)-based composite materials have been widely used in aerospace, rail transportation, electronics, and medical devices due to their high strength, high modulus, and excellent designability and processability. However, their application is limited by their high melting point, high melt viscosity, and high processing difficulty. In particular, the addition of fibers significantly increases the melt viscosity of PAEK materials during processing, leading to melt fracture, extrusion difficulties, residual bubbles, low mechanical properties of the finished parts, and poor surface quality. To reduce the processing difficulty of PAEK-based composite materials and solve the melt fracture problems caused by traditional physical blending methods, it is necessary to improve the melting point and melt flowability of PAEK-based composite materials.

[0003] The preparation of polyaryletherketone (PAEK) composites typically involves a physical blending method, where fiber reinforcements are blended with resin and then extruded using a twin-screw extruder. The extruded wires are granulated and then molded using methods such as compression molding and injection molding. This method produces composite particles in two steps, usually using fiber powder with a length of 60-180 μm to ensure the melt viscosity of the composite and the mechanical strength of the molded parts. During the molding process, the processing temperature is typically greater than 380°C. o C. The forming pressure is between 20-70 MPa. Physical blending modification of composite materials often encounters the problem of uneven filler dispersion, leading to uneven melt viscosity during extrusion. The strength of composite samples formed in different processing stages varies. Similarly, nanoparticles in wet blending also exhibit problems such as sedimentation and agglomeration. This significantly limits the processing and forming methods of polyaryletherketone (PAEK) composite materials and places high demands on forming equipment, further increasing processing costs and limiting the ability of PAEK composite materials to form complex structures. Summary of the Invention

[0004] The technical problem solved by this invention is to address the shortcomings of existing technologies by proposing a low-melting-point polyaryletherketone (PAEK)-based composite material, its in-situ synthesis method, and its application. Specifically, this invention provides an in-situ synthesis method for low-melting-point PAEK-based composite materials and its application in the field of 3D printing. By designing PAEK materials with different chemical structures and adding fillers such as, but not limited to, carbon nanotubes and carbon fibers to the reaction system, a one-pot in-situ synthesis of PAEK-based composite materials with different fillers can be achieved. Its core innovation lies in: Low-melting-point chemical structure design: -OH modified nanofillers, including but not limited to carbon nanotubes, carbon fibers, cage-type polysilsesquioxane (POSS), etc., are reacted with diphenyl sulfone, 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, and 4,4'-biphenylhydrazine. By adjusting the content of the four reactants and the ratio of the catalyst, a low-melting-point PAEK-based composite material is finally obtained.

[0005] Improved filler dispersibility: This addresses the problem of uneven filler dispersion encountered in the physical blending modification of composite materials, as well as issues such as agglomeration and sedimentation of nanofillers in wet blending. Modified nanofillers are used to disperse in diphenyl sulfone, and continuous stirring during polymerization ensures thorough dispersion in the reaction system.

[0006] Composite material preparation method: Abandoning the traditional composite material blending and modification preparation method, the filler and reactive monomer are added to the reaction system in a one-pot method, and the composite material is synthesized in situ through copolymerization. The final composite material is prepared into filaments with a diameter of 1.75±0.05mm by a single screw extruder for 3D printing.

[0007] The technical solution of this invention is: A low-melting-point polyaryletherketone-based composite material, the raw materials of which include 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, diphenyl sulfone, catalyst, and 4,4'-biphenylhydrazine; Based on the fact that the total mass of 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, catalyst, and 4,4'-biphenyldiphenol in the raw materials of this composite material is 100%, the mass percentage of each component is as follows: 4,4'-Difluorobenzophenone 35%-50% 1,4'-p-hydroxyphenol 10%-30% Reinforcing filler 5%-30% Catalyst 2%-5% 4,4'-Bisphenol A 5%-10% Let the sum of the masses of 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, catalyst, and 4,4'-biphenyl be M, then the mass of diphenyl sulfone is (1.5-2)*M; The reinforcing fillers include, but are not limited to, carbon fiber, quartz fiber, basalt fiber, aramid fiber, carbon nanotube, carbon black, graphene, graphene nanosheets, carbon nanofiber, nano silica, nano calcium carbonate, nano boron nitride, nano copper, nano silver, nano zinc oxide, cage-type polysilsesquioxane (POSS), metal-organic framework compounds (MOFs), and covalent organic framework compounds (COFs). The size of the reinforcing filler is no greater than 10 mm; The catalyst is at least one of anhydrous potassium carbonate, anhydrous sodium carbonate, cesium carbonate, potassium hydroxide, and sodium hydroxide.

[0008] A method for preparing a low-melting-point polyaryletherketone-based composite material, the method comprising the following steps: The first step is to pretreat the selected reinforcing filler, which is carbon fiber, quartz fiber, basalt fiber, aramid fiber, carbon nanotube, carbon black, nano calcium carbonate or nano boron nitride. The pretreatment method is as follows: place the reinforcing filler in a muffle furnace and slowly heat it to 350-500℃ for 6-8 hours; When the selected reinforcing filler is graphene, cage-type polysilsesquioxane (POSS), metal-organic framework (MOF) or covalent organic framework (COF), proceed directly to the second step. The second step involves mixing the reinforcing filler, diphenyl sulfone, and 4,4'-difluorobenzophenone, stirring, and heating to react and obtain mixed system A. Third step: Add 1,4'-p-hydroxyphenol and part of the catalyst to the mixture A obtained in the second step, stir, heat to react, and after the reaction is completed, mix system B is formed. In the fourth step, 4,4'-biphenyl hydroquinone and the remaining catalyst are added to the mixture B obtained in the third step, stirred, heated to react, and after the reaction is completed, low-melting-point polyarylether ketone-based composite material powder is obtained.

[0009] In the second step, the heating temperature is 100-180℃, the heating time is 40min-1.5h, and the stirring speed is 80-100rpm; In the third step, the heating temperature is 250-280℃, the heating time is 2-3 hours, and the stirring rate is 60-80 rpm. The mass ratio of the catalyst in the third step to the catalyst in the fourth step is 9:1; In the fourth step, the heating temperature is 290-300℃, the heating time is 1-2 hours, and the stirring rate is 90-120 rpm.

[0010] The method for preparing low-melting-point polyaryletherketone-based composite material powder into low-melting-point polyaryletherketone-based composite material wires is as follows: 1) Heat the screw extruder to 210-320℃ and stabilize for 3-5 minutes; 2) Add the low-melting-point polyaryletherketone-based composite material powder into the feeder, and adjust the feeder speed to the screw speed to be 1:8; 3) Observe that the extruded material at the die head is the corresponding color (e.g., carbon fiber is dark black), stabilize for 10-30 seconds, and start extruding to obtain low melting point polyaryletherketone-based composite material wire. Wind the low melting point polyaryletherketone-based composite material wire, and the winding speed is consistent with the speed of the traction roller group. With the traction roller set speed set to 100rpm-400rpm, the diameter of the low-melting-point polyaryletherketone composite wire obtained is 1.75 mm ± 0.05 mm.

[0011] The screw extruder is a twin-screw extruder or a single-screw extruder; The prepared low-melting-point polyaryletherketone-based composite filaments were applied to 3D printing.

[0012] Beneficial effects This invention lowers the melting point and viscosity of polyaryletherketone (PAK) materials by adjusting the ratio of 1,4'-p-hydroxyphenol to 4,4'-biphenylhydrazine and the amount of catalyst in the reaction raw materials, while simultaneously adding reinforcements to the reaction system. This also solves the problems of sedimentation, agglomeration, and uneven dispersion of reinforcements in the reaction system during the preparation of PAK-based composite materials. The reduction in melting point and viscosity improves the molding efficiency of PAK-based composite materials and reduces the cost of 3D printing PAK-based composite materials. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the DSC curve of the powder in the example. Detailed Implementation

[0014] To better understand the above-mentioned objectives, technical solutions, and advantages of the present invention, the present invention will be further described below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0015] Example 1 A low-melting-point polyaryletherketone-based composite material, the raw materials of which include 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, diphenyl sulfone, catalyst, and 4,4'-biphenylhydrazine; Based on the fact that the total mass of 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, catalyst, and 4,4'-biphenyldiphenol in the raw materials of this composite material is 100%, the mass percentage of each component is as follows: 4,4'-Difluorobenzophenone 50% 1,4'-p-hydroxyphenol 30% 10% of the reinforcing filler 3% catalyst 4,4'-Bisphenol 7% The mass fraction of diphenyl sulfone is 200%; The reinforcing filler is carbon fiber with a size of 100-180μm; The catalyst is anhydrous potassium carbonate; A method for preparing a low-melting-point polyaryletherketone-based composite material, the method comprising the following steps: The first step is to pretreat the reinforcing filler carbon fiber; The pretreatment method is as follows: place the carbon fiber in a muffle furnace and slowly heat it to 450℃ for 6 hours (heating rate is 2℃ / min); The second step involves mixing 3g of carbon fiber, 200g of diphenyl sulfone, and 50g of 4,4'-difluorobenzophenone, stirring, and heating to react and obtain mixed system A. Third step: Add 30g of 1,4'-p-hydroxyphenol and 2.7g of catalyst to the mixture A obtained in the second step, stir, heat to react, and after the reaction is completed, mix system B. In the fourth step, 7g of 4,4'-biphenyl hydroquinone and the remaining 0.3g of catalyst were added to the mixture B obtained in the third step. The mixture was stirred and heated to allow the reaction to proceed. After the reaction was complete, a low-melting-point polyarylether ketone-based composite material powder was obtained. The obtained powder was subjected to DSC testing, and the DSC curve is shown below. Figure 1 As shown, by Figure 1 It is known that the melting point of the low-melting-point polyaryletherketone-based composite material is 306℃; In the second step, the heating temperature is 120℃, the heating time is 40 min, and the stirring speed is 80 rpm; In the third step, the heating temperature is 260℃, the heating time is 2h, and the stirring rate is 70rpm. In the fourth step, the heating temperature is 290℃, the heating time is 1 hour, and the stirring rate is 120 rpm.

[0016] The method for preparing low-melting-point polyaryletherketone-based composite material powder into low-melting-point polyaryletherketone-based composite material wires is as follows: 1) Heat the screw extruder to 210℃ in the first temperature zone, 240℃ in the second temperature zone, 280℃ in the third temperature zone, 280℃ in the fourth temperature zone, 300℃ in the fifth temperature zone, and 320℃ in the sixth temperature zone, and stabilize for 5 minutes. 2) Add the low-melting-point polyaryletherketone-based composite material powder into the feeder, and adjust the feeder speed to 10 rpm and the screw speed to 80 rpm; 3) Observe that the extruded material at the die head is dark black like carbon fiber. After stabilizing for 30 seconds, start extruding to obtain low melting point polyaryletherketone composite material wire. Wind the low melting point polyaryletherketone composite material wire at a speed of 200 rpm. With the traction roller set speed set to 200 rpm, the diameter of the low-melting-point polyaryletherketone composite wire obtained is 1.75 mm ± 0.05 mm.

[0017] The screw extruder is a single-screw extruder; The prepared low-melting-point polyaryletherketone-based composite material filament was applied to FDM 3D printing to obtain a spline. A tensile spline was obtained according to ISO-527 standard, with dimensions of 80mm*4mm*2mm. A bending spline was obtained according to ISO-178 standard, with dimensions of 80mm*10mm*4mm. The tensile properties of the obtained tensile specimens were tested, and the bending properties of the obtained bending specimens were tested. The test results are shown in Table 1. Table 1

[0018] pass Figure 1 As shown in Table 1, the mechanical properties of the obtained polyarylether ketone-based composite material are improved when the melting point is reduced to 306℃ compared with those of the polyarylether ketone-based composite material obtained by physical blending in the prior art.

[0019] Example 2 The difference from the low-melting-point polyaryletherketone-based composite powder prepared in Example 1 is that: The reinforcing agent is a cage-type polysilsesquioxane and does not require pretreatment. The catalyst is a mixture of anhydrous potassium carbonate and anhydrous sodium carbonate, with a mass ratio of 1:6. The resulting powder has a melting point of 315℃.

[0020] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-melting-point polyaryletherketone-based composite material, characterized in that: The raw materials for this composite material include 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, diphenyl sulfone, catalyst, and 4,4'-biphenylhydrazine; Based on the fact that the total mass of 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, catalyst, and 4,4'-biphenyldiphenol in the raw materials of this composite material is 100%, the mass percentage of each component is as follows: 4,4'-Difluorobenzophenone 35%-50% 1,4'-p-hydroxyphenol 10%-30% Reinforcing filler 5%-30% Catalyst 2%-5% 4,4'-Bisphenol A 5%-10% Let the total mass of 4,4'-difluorobenzophenone, 1,4'-p-hydroxyphenol, reinforcing filler, catalyst, and 4,4'-biphenyl be M, then the mass of diphenyl sulfone is (1.5-2)*M.

2. The low-melting-point polyaryletherketone-based composite material according to claim 1, characterized in that: The reinforcing filler is at least one of carbon fiber, quartz fiber, basalt fiber, aramid fiber, carbon nanotube, carbon black, graphene, cage-type polysilsesquioxane, metal-organic framework compound, and covalent organic framework compound.

3. The low-melting-point polyaryletherketone-based composite material according to claim 1, characterized in that: The size of the reinforcing filler is no greater than 10 mm.

4. The low-melting-point polyaryletherketone-based composite material according to claim 1, characterized in that: The catalyst is at least one of anhydrous potassium carbonate, anhydrous sodium carbonate, cesium carbonate, potassium hydroxide, and sodium hydroxide.

5. A method for preparing a low-melting-point polyaryletherketone-based composite material, characterized in that... The steps of this method include: The first step is to pretreat the selected reinforcing filler, which is carbon fiber, quartz fiber, basalt fiber, aramid fiber, carbon nanotube or carbon black. The pretreatment method is as follows: place the reinforcing filler in a muffle furnace and slowly heat it to 350-500℃ for 6-8 hours; When the selected reinforcing filler is graphene, cage-type polysilsesquioxane, metal-organic framework compound or covalent organic framework compound, proceed directly to the second step. The second step involves mixing the reinforcing filler, diphenyl sulfone, and 4,4'-difluorobenzophenone, stirring, and heating to react and obtain mixed system A. Third step: Add 1,4'-p-hydroxyphenol and part of the catalyst to the mixture A obtained in the second step, stir, heat to react, and after the reaction is completed, mix system B is formed. In the fourth step, 4,4'-biphenyl hydroquinone and the remaining catalyst are added to the mixture B obtained in the third step, stirred, heated to react, and after the reaction is completed, low-melting-point polyarylether ketone-based composite material powder is obtained.

6. The method for preparing a low-melting-point polyaryletherketone-based composite material according to claim 5, characterized in that: In the second step, the heating temperature is 100-180℃, the heating time is 40min-1.5h, and the stirring speed is 80-100rpm.

7. The method for preparing a low-melting-point polyaryletherketone-based composite material according to claim 5, characterized in that: In the third step, the heating temperature is 250-280℃, the heating time is 2-3 hours, and the stirring rate is 60-80 rpm. The mass ratio of the catalyst in the third step to the catalyst in the fourth step is 9:1; In the fourth step, the heating temperature is 290-300℃, the heating time is 1-2 hours, and the stirring rate is 90-120 rpm.

8. A method for preparing low-melting-point polyaryletherketone-based composite material wires from low-melting-point polyaryletherketone-based composite material powder, characterized in that... The steps are as follows: 1) Heat the screw extruder to 210-320℃ and stabilize for 3-5 minutes; 2) Add the low-melting-point polyaryletherketone-based composite material powder into the feeder, and adjust the feeder speed to the screw speed to be 1:8; 3) Observe that the extruded material at the die head is the corresponding color (e.g., carbon fiber is dark black), stabilize for 10-30 seconds, and start extruding to obtain low melting point polyaryletherketone-based composite material wire. Wind the low melting point polyaryletherketone-based composite material wire, and the winding speed is consistent with the speed of the traction roller group. With the traction roller set speed set to 100rpm-400rpm, the diameter of the low-melting-point polyaryletherketone composite wire obtained is 1.75 mm ± 0.05 mm.

9. The method according to claim 8, characterized in that: The screw extruder is either a twin-screw extruder or a single-screw extruder.

10. An application of a low-melting-point polyaryletherketone-based composite material, characterized in that: The low-melting-point polyaryletherketone-based composite filament prepared according to claim 8 was applied to 3D printing.

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