Medical imaging continuous carbon fiber / PAEK composite material bone fracture plate and preparation method thereof

Abstract

The invention relates to a medical imaging continuous carbon fiber / PAEK composite material bone fracture plate and a preparation method thereof, and the preparation method comprises the following steps: premixing PAEK fine powder and a heat stabilizer, then carrying out melt blending extrusion and granulation to obtain PAEK granules, and carrying out melt spinning on the PAEK granules to obtain PAEK fibers; pAEK fibers and continuous carbon fibers are woven to obtain a CF / PAEK mixed fabric; wherein an imaging agent is added before melt blending of PAEK granules, or the imaging agent is loaded on continuous carbon fibers by adopting a solution impregnation method; the CF / PAEK mixed fabric is sequentially stacked and laid according to the angle, the CF / PAEK mixed fabric is placed in a bone fracture plate mold to be subjected to compression molding, then rough machining, finish machining and polishing treatment are conducted, and the continuous carbon fiber / PAEK composite material bone fracture plate product capable of achieving medical imaging is obtained. The material has the advantages of high mechanical strength, good fatigue resistance, no corrosion, good biocompatibility, and long-term fluorescence development or X-ray development effect.

Description

Technical Field

[0001] The invention relates to the technical field of medical orthopedic materials, and in particular to a continuous carbon fiber / PAEK composite bone fracture plate capable of medical imaging and a preparation method thereof. Background Art

[0002] Polyaryletherketone (PAEK) thermoplastic engineering plastics have the advantages of excellent mechanical strength, high temperature resistance, fatigue resistance, radiation resistance, chemical resistance, self-lubrication, good biocompatibility, etc., and are widely used in aerospace, military, medical and other fields. Continuous carbon fiber CF / PAEK thermoplastic composites can achieve effective regulation of strength and modulus by adjusting the fiber content, achieving an elastic modulus that matches human bones (cortical bone 17.0-20.0GPa, cancellous bone 3.2-7.8GPa), and reducing the "stress shielding" effect. At the same time, the material is also superior to metal alloy materials in resistance to body fluid corrosion and fatigue resistance, and is more suitable for use as bone plates.

[0003] After medical implants are used in the human body, non-invasive means are needed to diagnose the matching of the bone plate and the human skeleton and the bone healing status. In vivo optical imaging technology mainly includes two technologies: bioluminescence and fluorescence imaging. Bioluminescence imaging uses luciferase genes to label cells or DNA, and uses the protease produced by it to react with the corresponding substrate to produce a probe light signal in the body; while fluorescence imaging uses fluorescent dyes for labeling, and the fluorescence produced by fluorescent dyes can form a fluorescent light source in the body. For example, indocyanine green ICG can absorb and excite near-infrared light at the same time, can bind to plasma proteins, has no known metabolites, is completely excreted by the liver, has very little toxic side effects, and was approved by the FDA for clinical use as a contrast agent in 1959. In addition, since the chemical structure of PAEK only contains elements with low electron density and low specific gravity such as C, H, and O, and no elements with high electron cloud density, it cannot absorb a large amount of electromagnetic spectrum and cannot be detected by X-rays. Summary of the invention

[0004] In order to overcome the problem that conventional materials as bone plates have poor mechanical properties and cannot be used for medical imaging, a continuous carbon fiber / PAEK composite bone plate capable of medical imaging and a preparation method thereof are provided. The radial bone plate and humeral bone plate prepared by the present invention have high mechanical strength, good fatigue resistance, no corrosion, good biocompatibility, and long-term X-ray development effect or fluorescence development effect, and are a preferred material to replace metal bone plates.

[0005] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0006] A method for preparing a continuous carbon fiber / PAEK composite bone plate capable of medical imaging comprises the following steps:

[0007] S1, premixing PAEK fine powder and heat stabilizer after drying, and then obtaining PAEK pellets after melt blending, extrusion and granulation; and obtaining PAEK fibers by melt spinning the PAEK pellets;

[0008] S2, weaving the PAEK fiber and continuous carbon fiber to obtain a CF / PAEK blended fabric;

[0009] Wherein, the imaging agent is added to the PAEK pellets before melt blending and premixed with other materials, or the imaging agent is loaded on the continuous carbon fiber by solution impregnation method;

[0010] S3, stacking and laying the CF / PAEK blended fabric in order according to angles, placing it in a bone plate mold for compression molding to obtain a bone plate preform;

[0011] S4. The preformed bone plate is subjected to rough machining, fine machining and polishing treatments in sequence to obtain a continuous carbon fiber / PAEK composite bone plate product capable of medical imaging.

[0012] Furthermore, the CF / PEEK blended fabric comprises, based on 100% by mass, 50%-80% of continuous carbon fibers, 1%-10% of imaging agents, 0.1%-0.5% of thermal stabilizers, and the remainder being PAEK.

[0013] Furthermore, the PAEK fine powder is selected from one or more of PAEK, PEEK, PEKK, PEK, and PEEKK resins; the imaging agent is selected from X-ray imaging substances or fluorescent imaging substances, and is a pharmaceutical grade substance; and the thermal stabilizer is a mixture of zinc stearate and calcium stearate.

[0014] Preferably, further, the X-ray imaging substance is selected from one or more of iodixanol (IDX), iodohexanol (IHX), iodobiturol, triiodobenzoic acid, barium sulfate, zirconium dioxide, calcium carbonate, titanium dioxide, bismuth trioxide, bismuth oxychloride, bismuth basic carbonate, ferric oxide, ferrous oxide, and tungsten; the X-ray imaging substance is added at a time of premixing the imaging agent with other materials before melt blending of the PAEK pellets;

[0015] The fluorescent imaging substance is selected from one or more of phenylalanine (2-amino-3-phenylpropionic acid, fluorescence peak 282nm), tyrosine (2-amino-3-p-hydroxyphenylpropionic acid, fluorescence peak 303nm), tryptophan (β-indolylalanine, fluorescence peak 348nm), new indocyanine green (fluorescence peak 890nm), and fluorescein isothiocyanate (fluorescence peak 520nm); the timing of adding the fluorescent imaging substance is: dissolving the fluorescent imaging substance in water, impregnating the continuous carbon fiber with solution so that the fluorescent imaging substance is loaded on the continuous carbon fiber, and before solution impregnation, the continuous carbon fiber is also subjected to plasma surface treatment.

[0016] Furthermore, the melt blending extrusion described in S1 adopts a twin-screw extruder with a screw diameter greater than 60 mm and a screw aspect ratio L / D greater than 50; the extrusion process parameters are: a main engine speed of 100-600 rpm, a barrel adopts 15 heating temperature zones, and the temperature of each section is set according to the processing direction as follows: the first section is within the range of 340-350°C, the second to ninth sections are within the range of 355-380°C, the tenth to fourteenth sections are within the range of 380-385°C, and the fifteenth section is within the range of 370-375°C, wherein the twelfth and thirteenth sections are provided with vacuum exhaust ports.

[0017] Furthermore, the melt spinning in S1 is obtained by extruding the melt through a single screw extruder and then processing it by drawing. The barrel temperature of the single screw extruder is set to 350°C in zone one, 375°C in zone two, and 385°C in zone three. The drawing process is as follows: the main engine speed is 10-15rpm, the first-position drawing speed is 12-18m / min, the second-position drawing speed is 32-38m / min, and the third-position drawing speed is 28-32m / min. The diameter range of the obtained PAEK fiber is between 0.1-0.5mm.

[0018] Further, the specification of the continuous carbon fiber in S2 is 12K, T700-T800, and the width is ≥1mm; the weaving method is to use the continuous carbon fiber as the weft and the PAEK fiber as the warp for plain weaving, and the ratio of the number of the weft to the number of the warp is 1:2-10;

[0019] The continuous carbon fibers in the CF / PAEK blended fabric account for 50wt%-80wt%.

[0020] Furthermore, the stacking is performed in the following order and angle from bottom to top: [0° / 0° / 0° / 0° / 0° / 0° / 0° / 45° / -45° / 0° / 90° / 0° / 0° / 0° / 0°] sThere are 28 layers in total, including 22 layers of 0° plies, 2 layers of 90° plies, and 4 layers of 45° plies. The 0° plies provide the main tensile strength, while the 90° plies mainly bear the lateral load, and the 45° plies provide shear strength, stiffness and toughness.

[0021] Furthermore, the compression molding process is as follows: high temperature and high pressure molding is performed for 20-150 minutes at a temperature of 375-400°C, a pressure of 12-20MPa, and a pressurization frequency of 1MPa / 5min. After molding, the temperature is slowly reduced to 220-280°C at a rate within the range of 0.3-3°C / min, and then the temperature is rapidly reduced to 120-140°C at a rate of more than 5°C / min, and demolding is performed. During the molding process, the PAEK in the continuous CF / PAEK blended fabric strip melts and infiltrates the CF filament bundle, and each layer of material is bonded into one, pressurized and vented, thereby reducing the porosity inside the composite material and improving the mechanical strength of the composite product; the temperature range of 220-280°C is the main crystallization range of PAEK resin. In this process, slow cooling can be used to greatly improve the crystallinity of the resin, thereby improving the mechanical strength of the PAEK resin and its composite products; if the demolding is performed at a temperature higher than the glass transition temperature of 143°C of the PAEK resin, the microscopic molecular structure will be The structure is in a highly elastic state, and the molecular chains are still in motion. Demolding causes the preform to quickly lose the constraints of external forces, and the molecular chains move irregularly, causing warping and deformation. If the demolding temperature is too low, the characteristics of metal materials are thermal expansion and contraction. The lower the temperature, the greater the shrinkage of the metal mold frame. The continuous carbon fiber CF / PAEK composite material has almost no shrinkage due to the constraints of the carbon fiber filaments. This will cause the preform to be stuck in the mold and cannot be easily removed. It can only be removed by increasing external force. This has a very high probability of causing extrusion delamination and cracking of the preform.

[0022] Furthermore, the tool used for the rough machining is a diamond tool or a high tungsten steel tool, a five-axis machining center is used, the tool selection is D4-D8, the speed of the rough machining is 6500-12500rpm, the cutting depth is 0.2-0.5mm, and the feed rate is 500-2000mmpm;

[0023] The tool used for the finishing process is a diamond tool or a high-tungsten steel tool, and a five-axis machining center is used. The tool is selected as D4-D8. The speed of the finishing process is 8500-25000rpm, the cutting depth is ≤0.1mm, and the feed rate is 500-2000mmpm. The following matters should be noted during processing: (1) The processing must be fully cooled to avoid excessive local temperature; (2) During processing, pay attention to check the tool wear at any time to avoid product stratification due to tool wear; (3) The tool swing is controlled within 0.01mm, which not only ensures the processing accuracy, but also helps to extend the tool life; (4) For positions or products with high precision requirements, 2-4 semi-finishing processes are required, followed by finishing processes; (5) The tool runs smoothly during the processing process, which can reduce processing deformation and ensure product processing quality.

[0024] Another aspect of the present invention provides a medically imageable continuous carbon fiber / PAEK composite bone plate obtained by the above preparation method, wherein the bone plate is a humeral bone plate or a radial bone plate.

[0025] Beneficial technical effects:

[0026] (1) The continuous carbon fiber / PAEK composite radial bone plate or humeral bone plate prepared by the method of the present invention has the advantages of light weight, high specific strength, moderate modulus close to human bones, low porosity, good interlayer toughness, good fatigue resistance, non-toxicity, non-corrosiveness, long-term X-ray development or fluorescence development, etc.; The present invention adopts continuous CF / PAEK mixed fabric composite lamination molding, and obtains a bone plate product with better mechanical properties by designing the laying angle, sequence, and number of layers;

[0027] (2) The process of the present invention is based on high temperature and high pressure molding technology, and the continuous carbon fiber CF / PAEK mixed fabric is molded and melted. Under the applied pressure, the shape changes to obtain the basic appearance of the corresponding bone plate product, while improving the effect of infiltrating the CF tow, bonding each layer of material into one, pressurizing and exhausting, reducing the porosity inside the composite material, and improving the mechanical strength of the composite product;

[0028] (3) The present invention performs machining on the preformed part obtained by compression molding, thereby avoiding the problems of poor product surface finish due to tool wear, poor product assembly due to unstable processing dimensions, frequent tool replenishment and tool change due to inadequate processing dimensions, and product undersize due to excessive upper and lower tapers of the orifice, thereby obtaining a product with good dimensional accuracy and quality;

[0029] (4) The static four-point bending force of the bone plate prepared by the present invention at room temperature is 1000-3000N, the dynamic four-point bending fatigue limit is at least 2 million times under a loading force of 500N, and the interlaminar shear strength exceeds 85MPa.

[0030] (5) The continuous carbon fiber / PAEK composite bone plate capable of medical imaging prepared by the process of the present invention solves the technical difficulties encountered by the existing metal bone plates, is beneficial to the healing of human bones, reduces the pain that patients may suffer from fractures after healing, and will reduce medical costs, thereby alleviating the economic burden on patients; the present invention combines an imaging agent with a medical implant, which can be imaged by fluorescence or X-ray after surgery, making it easier for doctors to observe the recovery status of the subsequent fracture trauma site, and can make the diagnosis of postoperative recovery status safer and more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the front structural dimension diagram of the continuous carbon fiber / PAEK composite radial bone plate product. The data units marked in the figure are mm.

[0032] Figure 2 This is the side structural dimension diagram of the continuous carbon fiber / PAEK composite radial bone plate product. The data marked in the figure is in mm.

[0033] Figure 3 This is a physical picture of the continuous carbon fiber / PAEK composite radial bone plate product;

[0034] Figure 4 The X-ray imaging effect comparison of the continuous carbon fiber / PAEK composite radial bone plate obtained in Example 1 and Comparative Example 1;

[0035] Figure 5 This is an X-ray image at 57 kV after simulating implantation of the continuous carbon fiber / PAEK composite radial bone plate of Example 1 using a human bone model;

[0036] Figure 6 Interlayer SEM images of the continuous carbon fiber / PAEK composite radial bone fracture plates of Example 1 and Example 2, wherein the scale lengths of the SEM images of the product of Example 1 from left to right are 200 microns, 100 microns, and 200 microns, respectively; the scale lengths of the SEM images of the product of Example 2 from left to right are 200 microns, 100 microns, and 50 microns, respectively;

[0037] Figure 7 This is the front dimension diagram of the continuous carbon fiber / PAEK composite humeral bone plate product. The data units marked in the figure are mm.

[0038] Figure 8 This is a physical picture of the continuous carbon fiber / PAEK composite humeral bone plate product;

[0039] Fig. 9 Surface and interlayer SEM images of the continuous carbon fiber / PAEK composite humeral bone plate of Example 5. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be described clearly and completely below in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of 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. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0041] 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.

[0042] 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.

[0043] Example 1

[0044] A continuous carbon fiber / PAEK composite radial bone plate that can be developed by X-ray. The front dimensions of the radial bone plate are shown in the figure below. Figure 1 As shown, the side dimensions are as follows Figure 2 As shown in the actual picture Figure 3 As shown, it includes an integrally formed head and tail, the head is wider than the tail, the two sides of the head are not of equal height, the head is a special-shaped curved surface that fits the end of the human skeleton, the head has 8 large holes and three threading holes, the 8 large holes are arranged in two rows along the length direction of the head, 3 small holes are distributed on the higher side of the head and surround at least one large hole, the head and the tail are bent at an obtuse angle, and 11 large holes, 1 small hole and 1 long hole are regularly arranged in the center along the length direction of the tail.

[0045] The method for preparing the above-mentioned X-ray-developable continuous carbon fiber / PAEK composite radial bone fracture plate comprises the following specific steps:

[0046] S1. PEEK fine powder (melt index of 15 g / 10 min at 400°C and 2.16 kg test conditions) 100 kg, barium sulfate (pharmaceutical grade) 2 kg, calcium zinc heat stabilizer (pharmaceutical grade calcium stearate and zinc stearate mixture, calcium stearate and zinc stearate mass ratio of 7:3) 0.2 kg were dried at 100°C for 5 h and pre-mixed in a high-speed stirring mixer. Then, PEEK pellets (diameter 2 mm, length 3.5 m) were obtained by melt blending, extrusion and granulation in an extruder. m); the extrusion process parameters are as follows: the main engine speed of the twin-screw extruder is 100-600rpm, the barrel adopts 15 heating temperature zones, and the temperature settings of the first to fifteenth sections according to the processing direction are as follows: 350℃, 360℃, 360℃, 360℃, 365℃, 370℃, 370℃, 375℃, 375℃, 380℃, 380℃, 380℃, 380℃, 370℃, wherein the twelfth and thirteenth sections are provided with vacuum exhaust ports;

[0047] 100 kg of PEEK pellets were melt extruded, spun and cooled to obtain PEEK fiber filaments (diameter 0.2 mm) through a single screw extruder; the extrusion process parameters were as follows: the barrel temperature was set to: 350°C in zone 1, 375°C in zone 2, and 385°C in zone 3; the spun spinning process was as follows: main engine speed 11 rpm, first traction speed 15 m / min, second traction speed 35 m / min, and third traction speed 30 m / min;

[0048] S2, using continuous carbon fiber yarn (T800, 12K, width 2mm) as the weft and PEEK fiber filaments (diameter 0.2mm) as the warp for plain weaving, the number ratio of weft to warp is 1:10, and a CF / PEEK blended fabric is obtained. In this case, the mass percentage of each substance in the CF / PEEK blended fabric is controlled as follows: 55% continuous carbon fiber, 2% imaging agent, 0.2% thermal stabilizer, and the balance is PAEK;

[0049] S3, cutting the CF / PEEK blended fabric into a size of 330×305mm, with the weft direction as the 305mm length direction, i.e., the 0° direction of the bone plate, and stacking them in sequence from bottom to top according to [0° / 0° / 0° / 0° / 0° / 0° / 0° / 45° / -45° / 0° / 90° / 0° / 0° / 0°]s, with a total of 28 layers, placing them in a mold for compression molding, setting the program to heat up, and when the temperature rises to 375-380°C, manually stop heating and start pressurizing with a pressurizing pressure of 15MPa and a pressurizing frequency of 1MPa / 5min. The fabric is molded by keeping the temperature at a constant temperature for 150min, and then naturally cools down to 240°C after molding (the natural cooling rate is approximately in the range of 0.3-1°C / min), removes the insulation material, and then quickly cools down to 140°C at a rate of more than 10°C / min for demolding to obtain a continuous carbon fiber / PAEK composite radial bone plate preform that can be developed by X-ray;

[0050] S4, using D4 high tungsten steel tool to rough-process the obtained preform, the rough-processing speed is 6500rpm, the cutting depth is 0.3mm, and the feed rate is 500mmpm;

[0051] Replace the new D4 high tungsten steel tool for finishing, the finishing speed is 8500rpm, the cutting depth is 0.1mm, and the feed rate is 500mmpm;

[0052] Then it is polished, with a 1500-mesh stone grinding wheel for coarse grinding and a 2000-mesh cloth grinding wheel for fine grinding and polishing to improve the smoothness of the product surface, thus obtaining a continuous carbon fiber / PAEK composite radial bone plate product that can be developed by X-ray. The multiple channels of the product can increase the specific surface area of ​​the bone plate, increase the contact between the barium sulfate imaging agent and the bone, and barium sulfate has certain antibacterial properties, which is beneficial to bone healing.

[0053] The X-ray imaging effect of the radial bone plate product in this case is as follows Figure 4 As shown in the figure, it is well known that the greater the voltage, the stronger the X-ray penetration and the more difficult it is to image. Figure 4 It can be seen that the radius plate product in this case still has good imaging effect under 50kV X-ray test conditions.

[0054] After simulating the implantation of the radial bone plate product in this case using a human bone model, X-ray imaging was performed on an X-ray device at 57kV. The X-ray imaging is shown below: Figure 5 As shown by Figure 5 The tail of the radial plate (i.e. the straight plate part) and the hole thereon can be clearly seen, and the imaging effect is good.

[0055] The interlayer SEM image of the radial bone plate product in this case is as follows Figure 6As shown, there is no obvious stratification in the cross section of the radial bone plate, the interlayer bonding is good, and the resin infiltration effect is good, which ensures the interlayer strength of the radial bone plate.

[0056] Test: static four-point bending, according to standard YY / T 0342, dynamic four-point bending fatigue, according to standard YY / T1503, interlaminar shear strength, according to standard ASTM D2344. The X-rayable continuous carbon fiber / PAEK composite radial bone plate prepared in this case has a static four-point bending force of 2000N at room temperature, a dynamic four-point bending fatigue limit of 5.03 million times under a loading force of 500N, and an interlaminar shear strength of 105MPa.

[0057] Comparative Example 1

[0058] The structure and preparation of the radial bone plate in this case are the same as those in Example 1, except that barium sulfate is not added to S1.

[0059] The static four-point bending force of the radial bone plate in this case is 1350N at room temperature, the dynamic four-point bending fatigue limit is 2.26 million times under a loading force of 500N, and the interlaminar shear strength is 95MPa. Figure 4 As shown by Figure 4 It can be seen that the product in this case has a certain imaging effect under X-ray test conditions within 45kV, but when the voltage is increased to enhance the X-ray penetration, the imaging effect is lost under the X-ray test conditions of 47kV.

[0060] Example 2

[0061] A continuous carbon fiber / PAEK composite radial bone fracture plate capable of X-ray development has the same structure as that of Example 1, and its preparation method comprises the following specific steps:

[0062] S1. PEEK fine powder (melt index of 15 g / 10 min at 400°C and 2.16 kg test conditions) 100 kg, titanium dioxide (pharmaceutical grade) 5 kg, calcium zinc heat stabilizer (pharmaceutical grade calcium stearate and zinc stearate mixture, calcium stearate and zinc stearate mass ratio of 7:3) 0.2 kg were dried at 100°C for 5 h and pre-mixed in a high-speed stirring mixer. PEEK pellets (diameter 2 mm, length 3.5 mm) were obtained by melt blending, extrusion and granulation in an extruder. mm); the extrusion process parameters are as follows: the main engine speed of the twin-screw extruder is 100-600rpm, the barrel adopts 15 heating temperature zones, and the temperature settings from the first section to the fifteenth section in the processing direction are as follows: 350℃, 360℃, 360℃, 360℃, 365℃, 370℃, 370℃, 375℃, 375℃, 380℃, 380℃, 380℃, 380℃, 370℃, wherein the twelfth and thirteenth sections are provided with vacuum exhaust ports;

[0063] 100 kg of PEEK pellets were melt extruded, spun and cooled to obtain PEEK fiber filaments (diameter 0.2 mm) through a single screw extruder; the extrusion process parameters were as follows: the barrel temperature was set to: 350°C in zone 1, 375°C in zone 2, and 385°C in zone 3; the spun spinning process was as follows: main engine speed 11 rpm, first traction speed 15 m / min, second traction speed 35 m / min, and third traction speed 30 m / min;

[0064] S2, using continuous carbon fiber yarn (T800, 12K, width 2mm) as the weft and PEEK fiber filaments (diameter 0.2mm) as the warp for plain weaving, the ratio of the number of weft and warp is 1:10, to obtain a CF / PEEK blended fabric. In this case, the mass percentage of each substance in the CF / PEEK blended fabric is controlled as follows: continuous carbon fiber 55%, imaging agent 5%, heat stabilizer 0.2%, and the balance is PAEK;

[0065] S3, cutting the CF / PEEK blended fabric into a size of 330×305mm, with the weft direction as the 305mm length direction, i.e., the 0° direction of the bone plate, and stacking them in sequence from bottom to top according to [0° / 0° / 0° / 0° / 0° / 0° / 0° / 45° / -45° / 0° / 90° / 0° / 0° / 0°]s, with a total of 28 layers, placing them in a mold for compression molding, setting the program to heat up, and when the temperature rises to 380-385°C, manually stop heating and start pressurizing with a pressurizing pressure of 20MPa and a pressurizing frequency of 1MPa / 5min. The heat preservation and pressure maintenance are carried out for 120min for molding, and the temperature is naturally reduced to 260°C after molding (the natural cooling rate is approximately in the range of 0.3-1°C / min), the insulation material is removed, and the temperature is rapidly reduced to 120°C at a rate of more than 5°C / min for demolding to obtain a continuous carbon fiber / PAEK composite radial bone plate preform that can be X-rayed;

[0066] S4, using D4 high tungsten steel tool to rough-process the obtained preform, the rough-processing speed is 6500rpm, the cutting depth is 0.3mm, and the feed rate is 500mmpm;

[0067] Replace the new D4 high tungsten steel tool for finishing, the finishing speed is 8500rpm, the cutting depth is 0.1mm, and the feed rate is 500mmpm;

[0068] Then, it is polished, with a 1500-mesh stone grinding wheel for rough grinding and a 2000-mesh cloth grinding wheel for fine grinding and polishing to improve the surface finish of the product, thus obtaining a continuous carbon fiber / PAEK composite radial bone plate product that can be developed by X-ray. These pores in the product can increase the specific surface area of ​​the bone plate, increase the contact between the titanium dioxide imaging agent and the bone, and titanium dioxide has a certain antibacterial property, which is conducive to bone healing.

[0069] The interlayer SEM picture of the product in this case is as follows Figure 6 As shown, it can be seen that the interlayer and resin impregnation of the product in this case are good, but slightly lower than that of the product in Example 1.

[0070] Test: The X-rayable continuous carbon fiber / PAEK composite radial bone plate prepared in the above Example 2 has a static four-point bending force of 1700N at room temperature, a dynamic four-point bending fatigue limit of 3.5 million times under a loading force of 500N, and an interlaminar shear strength of 102MPa.

[0071] Example 3

[0072] The structure of a continuous carbon fiber / PAEK composite radial bone fracture plate that can be developed by X-ray is the same as that of Example 1, and its preparation method includes the following specific steps:

[0073] S1. PEEK fine powder (melt index of 15 g / 10 min at 400°C and 2.16 kg test conditions) 100 kg, bismuth trioxide (pharmaceutical grade) 10 kg, calcium zinc heat stabilizer (pharmaceutical grade calcium stearate and zinc stearate mixture, calcium stearate and zinc stearate mass ratio of 7:3) 0.2 kg were dried at 100°C for 5 h and pre-mixed in a high-speed stirring mixer, and then melt-blended, extruded and granulated in an extruder to obtain PEEK pellets (diameter 2 mm, length 3. 5mm); the extrusion process parameters are: the main engine speed of the twin-screw extruder is 100-600rpm, the barrel adopts 15 heating temperature zones, and the temperature settings from the first section to the fifteenth section in the processing direction are as follows: 350℃, 360℃, 360℃, 360℃, 365℃, 370℃, 370℃, 375℃, 375℃, 380℃, 380℃, 380℃, 380℃, 370℃, wherein the twelfth and thirteenth sections are provided with vacuum exhaust ports;

[0074] 100 kg of PEEK pellets were melt extruded, spun and cooled to obtain PEEK fiber filaments (diameter 0.2 mm) through a single screw extruder; the extrusion process parameters were as follows: the barrel temperature was set to: 350°C in zone 1, 375°C in zone 2, and 385°C in zone 3; the spun spinning process was as follows: main engine speed 11 rpm, first traction speed 15 m / min, second traction speed 35 m / min, and third traction speed 30 m / min;

[0075] S2, using continuous carbon fiber yarn (T800, 12K, width 2mm) as the weft and PEEK fiber filaments (diameter 0.2mm) as the warp for plain weaving, the ratio of the number of weft and warp is 1:10, to obtain a CF / PEEK blended fabric. In this case, the mass percentage of each substance in the CF / PEEK blended fabric is controlled as follows: 55% continuous carbon fiber, 10% imaging agent, 0.2% thermal stabilizer, and the balance is PAEK;

[0076] S3, cutting the CF / PEEK blended fabric into a size of 330×305mm, with the weft direction as the 305mm length direction, i.e., the 0° direction of the bone plate, and stacking them in sequence from bottom to top according to [0° / 0° / 0° / 0° / 0° / 0° / 0° / 45° / -45° / 0° / 90° / 0° / 0° / 0°]s, with a total of 28 layers, placing them in a mold for compression molding, setting the program to heat up, and when the temperature rises to 375-380°C, manually stop heating and start pressurizing with a pressurizing pressure of 12MPa and a pressurizing frequency of 1MPa / 5min. The fabric is molded by keeping the temperature at a constant temperature for 150min, and after molding, the fabric is naturally cooled to 280°C (the natural cooling rate is approximately in the range of 0.3-1°C / min), the insulation material is removed, and the fabric is rapidly cooled to 130°C at a rate of more than 8°C / min for demolding to obtain a continuous carbon fiber / PAEK composite radial bone plate preform that can be developed by X-ray;

[0077] S4, using D4 high tungsten steel tool to rough-process the obtained preform, the rough-processing speed is 6500rpm, the cutting depth is 0.3mm, and the feed rate is 500mmpm;

[0078] Replace the new D4 high tungsten steel tool for finishing, the finishing speed is 8500rpm, the cutting depth is 0.1mm, and the feed rate is 500mmpm;

[0079] Then, it is polished, with a 1500-mesh stone grinding wheel for rough grinding and a 2000-mesh cloth grinding wheel for fine grinding and polishing to improve the surface finish of the product, thus obtaining a continuous carbon fiber / PAEK composite radial bone plate product that can be developed by X-ray. These pores in the product can increase the specific surface area of ​​the bone plate, increase the contact between the bismuth trioxide imaging agent and the bone, and bismuth trioxide has certain antibacterial properties, which is beneficial to bone healing.

[0080] Test: The X-rayable continuous carbon fiber / PAEK composite radial bone plate prepared in the above Example 3 has a static four-point bending force of 1650N at room temperature, a dynamic four-point bending fatigue limit of 4.2 million times under a loading force of 500N, and an interlaminar shear strength of 103MPa.

[0081] Example 4

[0082] The preparation process of the X-rayable continuous carbon fiber / PAEK composite radial bone plate in this case is the same as that in Example 1, except that pharmaceutical grade calcium carbonate is used in S1. The X-rayable continuous carbon fiber / PAEK composite radial bone plate in this case has a static four-point bending force of 1450N at room temperature, a dynamic four-point bending fatigue limit of 2.6 million times under a loading force of 500N, and an interlaminar shear strength of 98MPa.

[0083] Example 5

[0084] A continuous carbon fiber / PAEK composite humeral bone plate capable of fluorescence development, the front dimensions of the product are as follows: Figure 7 As shown in the actual picture Figure 8 As shown, it includes an integrally formed trapezoidal head and an extension of its short side, with an overall length of 112.07mm, a long side width of 20.29mm, a short side width of 16.67mm, and a width of 12.05mm for the extension. The trapezoidal head is provided with 8 circular screw holes (circular aperture 4.15mm) and 12 circular threading holes (aperture 2.45mm), and 5 gourd-shaped screw holes (upper aperture 4.00mm, lower aperture 4.45mm) are distributed as a whole along the axial direction. A circular and elliptical overlapping screw hole (circular aperture 4.1mm, elliptical hole width 4.50mm, total hole length 12.45mm) is provided in the transition zone from the short side of the trapezoidal head to the extension.

[0085] The method for preparing the above-mentioned fluorescently developable continuous carbon fiber / PAEK composite humeral bone plate comprises the following specific steps:

[0086] S1. 100 kg of PEEK fine powder (melt index of 15 g / 10 min under 400°C and 2.16 kg test conditions) and 0.2 kg of calcium zinc heat stabilizer (a mixture of pharmaceutical grade calcium stearate and zinc stearate, with a mass ratio of calcium stearate to zinc stearate of 7:3) were dried at 100°C for 5 h and pre-mixed in a high-speed stirring mixer, and then melt-blended, extruded and granulated in an extruder to obtain PEEK pellets (2 mm in diameter and 3.5 mm in length); extrusion process The process parameters are as follows: the main engine speed of the twin-screw extruder is 100-600rpm, the barrel adopts 15-section heating temperature zones, and the temperature settings of the first section to the fifteenth section according to the processing direction are as follows: 350°C, 360°C, 360°C, 360°C, 365°C, 370°C, 370°C, 375°C, 375°C, 380°C, 380°C, 380°C, 380°C, 370°C, among which the twelfth and thirteenth sections are provided with vacuum exhaust ports;

[0087] 100 kg of PEEK pellets were melt extruded, spun and cooled to obtain PEEK fiber filaments (diameter 0.2 mm) through a single screw extruder; the extrusion process parameters were as follows: the barrel temperature was set to: 350°C in zone 1, 375°C in zone 2, and 385°C in zone 3; the spun spinning process was as follows: main engine speed 11 rpm, first traction speed 15 m / min, second traction speed 35 m / min, and third traction speed 30 m / min;

[0088] S2. Continuous carbon fiber yarn (T800, 12K, width 2mm) was subjected to surface treatment by vacuum plasma after removing the original surface sizing agent at a high temperature of 400°C. The internal plasma nozzle was 5mm away from the material surface, the plasma excitation frequency was 25KHz, the power during treatment was 3000W, the gas used during treatment was nitrogen or helium, the gas flow rate during treatment was 200L / min, and the treatment time was 10min.

[0089] Then, phenylalanine was dissolved in deionized water to obtain a phenylalanine solution with a concentration of 1 g / L, and the continuous carbon fiber treated with the former was immersed in the above phenylalanine solution for 3 hours to control the loading amount of phenylalanine on the carbon fiber. After vacuum drying, the continuous carbon fiber yarn was used as the weft and the PEEK fiber filaments (diameter 0.2 mm) were used as the warp for plain weaving. The ratio of the number of wefts to warps was 1:10 to obtain a CF / PEEK blended fabric. In this case, the mass percentage of each substance in the CF / PEEK blended fabric was controlled as follows: 55% of continuous carbon fiber, 5% of imaging agent, 0.2% of heat stabilizer, and the balance was PAEK.

[0090] S3. Cut the CF / PEEK blended fabric into a size of 330×305mm, with the weft direction as the 305mm length direction, i.e. the 0° direction of the bone plate, and lay them out in sequence from bottom to top according to [0° / 0° / 0° / 0° / 0° / 0° / 0° / 45° / -45° / 0° / 90° / 0° / 0° / 0°]s, for a total of 28 layers. Place them in a mold for compression molding, set the temperature to rise to 375-380°C, stop heating manually, and start pressurizing at a pressure of 15MPa and a frequency of 1MPa / 5min, heat preservation and pressure preservation for 30min for molding, naturally cool to 240℃ after molding (the natural cooling rate is about 0.3-1℃ / min), remove the insulation material, and then quickly cool to 140℃ for demoulding at a rate of more than 10℃ / min to obtain a continuous carbon fiber / PAEK composite humeral bone plate preform that can be fluorescently developed (phenylalanine as an imaging agent will inevitably produce thermal decomposition during the high-temperature molding process, but the thermal decomposition does not affect its fluorescent properties, and it is carbonized at high temperature to form carbon quantum dots with fluorescent properties);

[0091] S4, using D4 high tungsten steel tool to rough-process the obtained preform, the rough-processing speed is 12000rpm, the cutting depth is 0.5mm, and the feed rate is 2000mmpm;

[0092] Replace the new D4 high tungsten steel tool for finishing, the finishing speed is 20000rpm, the cutting depth is 0.1mm, and the feed rate is 2000mmpm;

[0093] Then, the product is polished, with a 1500-mesh stone grinding wheel for rough grinding and a 2000-mesh cloth grinding wheel for fine grinding and polishing to improve the surface finish of the product, thereby obtaining a continuous carbon fiber / PAEK composite humeral bone plate product that can be fluorescently developed.

[0094] The interlayer SEM picture of the product in this case is as follows Fig. 9 As shown, it can be seen that the carbon fiber is fully impregnated with the resin, and the addition of the imaging agent has no effect on the interlayer performance.

[0095] Test: The fluorescent continuous carbon fiber / PAEK composite humeral bone plate in this case has a static four-point bending force of 2700N at room temperature, a dynamic four-point bending fatigue limit of 6.2 million times under a loading force of 1000N, and an interlaminar shear strength of 102MPa.

[0096] Comparative Example 2

[0097] The structure and preparation process of the humeral plate in this case are the same as those in Example 5, except that no fluorescent imaging material is added, that is, in step S2, the plasma-treated continuous carbon fiber yarn is directly used as the weft and the PEEK fiber filaments (diameter 0.2 mm) are used as the warp for plain weaving and subsequent manufacturing.

[0098] The static four-point bending force of the humeral plate in this case at room temperature is 2150N, the dynamic four-point bending fatigue limit is 5.15 million times under a loading force of 1000N, and the interlaminar shear strength is 86MPa.

[0099] Example 6

[0100] The structure and preparation process of the humeral plate in this case are the same as those in Example 5, except that 2-amino-3-p-hydroxyphenylpropionic acid is used in step S1. The fluorescent imaging continuous carbon fiber / PAEK composite humeral plate in this case has a static four-point bending force of 2500N at room temperature, a dynamic four-point bending fatigue limit of 5.7 million times under a loading force of 1000N, and an interlaminar shear strength of 96MPa.

[0101] Example 7

[0102] The structure and preparation process of the humeral plate in this case are the same as those in Example 5, except that new indocyanine green is used in step S1. The fluorescent imaging continuous carbon fiber / PAEK composite humeral plate in this case has a static four-point bending force of 3000N at room temperature, a dynamic four-point bending fatigue limit of 6.5 million times under a loading force of 1000N, and an interlaminar shear strength of 105MPa.

[0103] Example 8

[0104] The structure and preparation process of the humeral plate in this case are the same as those in Example 5, except that fluorescein isothiocyanate is used in step S1. The fluorescent imaging continuous carbon fiber / PAEK composite humeral plate in this case has a static four-point bending force of 2200N at room temperature, a dynamic four-point bending fatigue limit of 5.2 million times under a loading force of 1000N, and an interlaminar shear strength of 87MPa.

[0105] It can be seen from Comparative Example 2 and Examples 5 to 8 that different fluorescent imaging substances improve the mechanical properties of materials to varying degrees, among which the new indocyanine green is of great help in improving the mechanical properties of materials.

[0106] 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 continuous carbon fiber / PAEK composite bone plate capable of medical imaging, characterized in that: The steps include: S1, premixing PAEK fine powder and heat stabilizer after drying, and then obtaining PAEK pellets after melt blending, extrusion and granulation; and obtaining PAEK fibers by melt spinning the PAEK pellets; S2, weaving the PAEK fiber and continuous carbon fiber to obtain a CF / PAEK blended fabric; Wherein, the imaging agent is added and premixed with other materials before the PAEK pellets are melt-blended, or the imaging agent is loaded on the continuous carbon fiber by a solution impregnation method; S3, stacking and laying the CF / PAEK blended fabric in order according to angles, placing it in a bone plate mold for compression molding to obtain a bone plate preform; S4. The preformed bone plate is subjected to rough machining, fine machining and polishing treatments in sequence to obtain a continuous carbon fiber / PAEK composite bone plate product capable of medical imaging.

2. The method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to claim 1, characterized in that: The CF / PEEK blended fabric comprises, by weight percentage of 100%, 50%-80% of continuous carbon fibers, 1%-10% of imaging agents, 0.1%-0.5% of thermal stabilizers, and the remainder being PAEK.

3. The method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to claim 2, characterized in that: The PAEK fine powder is selected from one or more of PAEK, PEEK, PEKK, PEK, and PEEKK resins; the imaging agent is selected from X-ray imaging substances or fluorescent imaging substances and is a pharmaceutical grade substance; the thermal stabilizer is a mixture of zinc stearate and calcium stearate.

4. The method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to claim 3, characterized in that: The X-ray imaging substance is selected from one or more of iodixanol, iodohexanol, iodobitol, triiodobenzoic acid, barium sulfate, zirconium dioxide, calcium carbonate, titanium dioxide, bismuth trioxide, bismuth oxychloride, bismuth basic carbonate, ferric oxide, ferrous oxide, and tungsten; the X-ray imaging substance is added at a time of premixing the imaging agent with other materials before melt blending the PAEK pellets; The fluorescent imaging substance is selected from one or more of 2-amino-3-phenylpropionic acid, 2-amino-3-p-hydroxyphenylpropionic acid, β-indolylalanine, new indocyanine green, and fluorescein isothiocyanate; the fluorescent imaging substance is added at a time of: dissolving the fluorescent imaging substance in water, impregnating the continuous carbon fiber with a solution so that the fluorescent imaging substance is loaded on the continuous carbon fiber, and before the solution impregnation, the continuous carbon fiber is also subjected to plasma surface treatment.

5. A method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to any one of claims 1 to 4, characterized in that: The melt blending extrusion described in S1 adopts a twin-screw extruder with a screw diameter greater than 60 mm and a screw aspect ratio L / D greater than 50; the extrusion process parameters are: the main engine speed is 100-600 rpm, the barrel adopts 15 heating temperature zones, and the temperature of each section is set according to the processing direction as follows: the first section is within the range of 340-350°C, the second to ninth sections are within the range of 355-380°C, the tenth to fourteenth sections are 380-385°C, and the fifteenth section is 370-375°C, wherein the twelfth and thirteenth sections are provided with vacuum exhaust ports.

6. A method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to any one of claims 1 to 4, characterized in that: The melt spinning in S1 is obtained by extruding the melt through a single screw extruder and then processing and drawing the melt. The barrel temperature of the single screw extruder is set to 350°C in zone 1, 375°C in zone 2, and 385°C in zone 3. The drawing process is as follows: the main engine speed is 10-15rpm, the first-position drawing speed is 12-18m / min, the second-position drawing speed is 32-38m / min, and the third-position drawing speed is 28-32m / min. The diameter range of the obtained PAEK fiber is between 0.1-0.5mm.

7. A method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to any one of claims 1 to 4, characterized in that: The specification of the continuous carbon fiber in S2 is 12K, T700-T800, and the width is ≥1mm; the weaving method is to use the continuous carbon fiber as the weft and the PAEK fiber as the warp for plain weaving, and the ratio of the weft to the warp is 1:2-10; The continuous carbon fibers in the CF / PAEK blended fabric account for 50wt%-80wt%.

8. A method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to any one of claims 1 to 4, characterized in that: The stacking is carried out in the following order and angle from bottom to top: [0° / 0° / 0° / 0° / 0° / 0° / 0° / 45° / -45° / 0° / 90° / 0° / 0° / 0° / 0°] s , a total of 28 floors.

9. A method for preparing a medically imageable continuous carbon fiber / PAEK composite bone plate according to any one of claims 1 to 4, characterized in that: The compression molding process is as follows: high temperature and high pressure molding for 20-150 minutes at a temperature of 375-400° C., a pressure of 12-20 MPa, and a pressurization frequency of 1 MPa / 5 min, and then slowly cooling to 220-280° C. at a rate of 0.3-3° C. / min after molding, and then rapidly cooling to 120-140° C. at a rate of more than 5° C. / min, and demolding; The rough machining adopts a diamond tool or a high tungsten steel tool, a five-axis machining center is used, and the tool is selected from D4 to D8. The speed of the rough machining is 6500-12500rpm, the cutting depth is 0.2-0.5mm, and the feed rate is 500-2000mmpm; The tool used for the finishing is a diamond tool or a high-tungsten steel tool, a five-axis machining center is used, and the tool selection is D4-D8. The speed of the finishing is 8500-25000rpm, the cutting depth is ≤0.1mm, and the feed rate is 500-2000mmpm.

10. The continuous carbon fiber / PAEK composite bone plate capable of medical imaging obtained by the preparation method according to any one of claims 1 to 4, characterized in that: The bone fracture plate is a humeral bone fracture plate or a radius bone fracture plate.

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