Fiber-reinforced polymer, preparation method thereof and internal fracture fixation product

Abstract

The invention provides a fiber-reinforced polymer, a preparation method thereof and a fracture internal fixation product. The fiber-reinforced polymer is obtained by polymerizing monomers or monomer prepolymers in fiber gaps, and the fracture internal fixation product can be obtained after one-time polymerization forming and machining, so that the preparation steps are simpler and more convenient, and the cost is lower. Meanwhile, the bonding strength between the fiber and the polymer can be higher by means of polymerization of the monomer or the monomer prepolymer in fiber gaps, so that the strength of the obtained fiber-reinforced polymer is higher, and a fracture internal fixation product is endowed with more excellent mechanical properties. Tests show that the weight-average molecular weight of the fiber-reinforced polymer is 1-800000 Da, and the mass content of fibers in the polymer is 10-90wt%.

Description

Technical Field

[0001] The invention belongs to the field of surgical implantation of fracture internal fixation instruments, and in particular relates to a fiber-reinforced polymer and a preparation method thereof, and a fracture internal fixation product. Background Art

[0002] Absorbable medical devices refer to medical devices made of materials that can be degraded and absorbed in the biological environment of the human body, that is, bioabsorbable medical material medical devices. Because absorbable medical devices can be degraded and absorbed in the body, no secondary surgery is required to remove them, and there is no residue in the body, they have attracted much attention from researchers in the medical field and have been put into clinical use on a large scale.

[0003] Usually, clinical needs require absorbable medical devices with higher strength that can replace metal products, but the traditional injection molding and extrusion processes are relatively simple, and the strength of the produced device products cannot meet clinical needs. To solve this technical problem, oriented self-reinforcement methods or fiber reinforcement methods are generally used to improve the strength of device products.

[0004] CN102406967A discloses a method for preparing a human body absorbable fiber / polycaprolactone degradable bone nail, comprising: "(1) mixing human body absorbable fiber, polycaprolactone slices and an interfacial compatibilizer, and then kneading to obtain a composite material; (2) heating the composite material in a mold, and then cooling the molded product and demolding it, and then cutting it, and finally sterilizing and packaging it to obtain it." This method adopts a fiber reinforcement method, but the fiber composite material needs to have a certain fluidity to facilitate kneading, injection molding, and extrusion processing. Therefore, only short fibers can be used in this method, and the amount of fiber added is relatively small, so the degree of increase in material strength is limited. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a fiber-reinforced polymer and a preparation method thereof, and a fracture internal fixation product. The fiber-reinforced polymer has excellent mechanical properties.

[0006] To achieve this object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a fiber-reinforced polymer obtained by polymerizing a monomer or a monomer prepolymer in the gaps between fibers; The mass content of the fiber in the polymer is 10-90 wt%.

[0007] Preferably, the fiber is a fiber with a rough surface or a fiber with a functional group on the surface, and the functional group is selected from any one or more of a hydroxyl group, a carboxyl group or an amino group.

[0008] Preferably, the fiber is subjected to stress stretching treatment, and the stress is 2~2000N.

[0009] Preferably, the fiber comprises any one or more of monofilament fiber, multifilament fiber or fiber braid.

[0010] Preferably, the fiber is selected from any one or more of carbon fiber, nylon fiber, stereopolymeric polylactic acid fiber, polyglycolide fiber, plant fiber, hydroxyapatite fiber, iron carbide fiber, iron nitride fiber or metal fiber.

[0011] Preferably, the fibers are arranged randomly or orderly.

[0012] Preferably, the surface of the fiber is loaded with any one or more of drugs, tissue components or materials that promote tissue growth.

[0013] Preferably, the monomer is selected from any one or more of L-lactide, D-lactide, meso-lactide, glycolide, ε-caprolactone, trimethylene carbonate or p-dioxanone.

[0014] Preferably, the weight average molecular weight of the polymer is 100,000-800,000 Da.

[0015] In a second aspect, the present invention provides a method for preparing the above-mentioned fiber-reinforced polymer, comprising the following steps: The monomer melt or monomer prepolymer melt is placed in the gap between fibers, and a polymerization reaction occurs under the action of a catalyst to obtain a fiber-reinforced polymer.

[0016] Preferably, the catalyst is selected from any one or more of a tin catalyst, a stannous catalyst or a zinc catalyst.

[0017] Preferably, the polymerization reaction temperature is 100-180° C., the time is more than 1 h, and the pressure is -0.1-20 MPa.

[0018] Preferably, the polymerization reaction is carried out in an inert atmosphere or in vacuum.

[0019] In a third aspect, the present invention provides a fracture internal fixation product, which is obtained by machining the above-mentioned fiber-reinforced polymer.

[0020] Preferably, the fracture internal fixation product has a bending strength of more than 100 MPa and a bending modulus of more than 2500 MPa.

[0021] Preferably, the fracture internal fixation product includes a bone plate, a bone nail, a bone screw or a bone fixation rod.

[0022] Compared with the prior art, the present invention has the following beneficial effects: Compared with the conventional melt blending of fibers and polymers in the prior art, the present invention uses monomers or monomer prepolymers to polymerize in the gaps between fibers to obtain fiber-reinforced polymers, which are polymerized once and then machined to obtain fracture internal fixation products. It can be seen that the preparation steps are simpler and the cost is lower. At the same time, the present invention uses monomers or monomer prepolymers to polymerize in the gaps between fibers to increase the bonding strength between fibers and polymers. Therefore, the obtained fiber-reinforced polymers have higher strength, thereby giving fracture internal fixation products better mechanical properties.

[0023] The fiber-reinforced polymer provided by the present invention may have a fiber content between 10% and 90%. According to tests, the weight average molecular weight of the fiber-reinforced polymer is 10,000 to 800,000 Da, and the flexural strength of the fracture internal fixation product obtained after processing is above 100 MPa, and the flexural modulus is above 2500 MPa. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In view of the problems of low fiber content and limited reinforced strength of fiber-reinforced polymers obtained in the prior art, the present invention provides a fiber-reinforced polymer obtained by polymerizing monomers or monomer prepolymers in fiber gaps.

[0026] In the present invention, the monomer is selected from any one or more of L-lactide, D-lactide, meso-lactide, glycolide, ε-caprolactone, trimethylene carbonate or p-dioxanone, and the monomer prepolymer is a product obtained by prepolymerizing any one or more of the above monomers. In some embodiments of the present invention, the monomer is preferably L-lactide, and the monomer prepolymer is preferably a poly-L-lactide prepolymer.

[0027] In the present invention, the conditions for selecting fibers are: (1) they cannot be dissolved in the monomer or monomer prepolymer of the polymer, or the dissolution rate of the fiber is lower than the polymerization rate; (2) the fiber should have excellent bonding ability with the polymer; (3) the mechanical properties of the fiber are not affected by the reaction temperature or are not greatly affected by it; (4) the mechanical properties of the fiber are stronger than the properties of the polymer substrate; and (5) the fiber does not affect the reaction of the monomer or monomer prepolymer.

[0028] Based on the above conditions, in the present invention, the fiber material can be an organic material, such as any one or more of stereopolymeric polylactic acid fiber, nylon fiber, polyglycolide fiber or plant fiber (such as flax fiber). The fiber material can also be an inorganic material, such as any one or more of hydroxyapatite fiber, carbon fiber, iron carbide fiber or iron nitride fiber. The fiber can also be a metal fiber, such as any one or more of metal iron fiber, aluminum fiber or magnesium aluminum alloy fiber.

[0029] In the present invention, the fiber can be selected from non-absorbable materials, such as carbon fiber, nylon fiber, etc.; or absorbable materials, such as homopolymers, copolymers, or two or more blends of homopolymers and copolymers of any one or more of L-lactide, D-lactide, meso-lactide, glycolide, ε-caprolactone, trimethylene carbonate or p-dioxanone, or metal iron fiber, aluminum fiber, magnesium aluminum alloy fiber, etc. The present invention preferably comprises fibers of absorbable material.

[0030] In some embodiments of the present invention, the fibers are preferably carbon fibers and / or stereopolymeric polylactic acid fibers, and / or polyglycolide fibers.

[0031] In the present invention, the fiber is a single fiber and / or a fiber braid. The single fiber may be a monofilament fiber and / or a multifilament fiber. The fiber braid is generally twisted into a wire, or braided into a wire, a belt, a sheet, a tube, or other structures. In the present invention, the fiber plays the role of "reinforcement", therefore, the strength, braiding process, and stereoscopic distribution of the fiber are very important.

[0032] In the present invention, the fibers may be randomly arranged, such as nonwoven fabrics, felts, needle-punched nonwoven fabrics or spunlace nonwoven fabrics, etc.; or they may be orderly arranged, such as regularly stacking or winding fibers or fiber braids to form regular fiber materials.

[0033] In some preferred embodiments of the present invention, the fibers may be pre-treated with stress stretching, wherein the stress is 2 to 2000 N, such as 2 N, 5 N, 10 N, 50 N, 100 N, 500 N, 1000 N, 1500 N or 2000 N, etc., to improve the bending strength of the fracture internal fixation product finally prepared. In some preferred embodiments of the present invention, orderly arranged fibers are selected for stress stretching.

[0034] In the present invention, in order to make the fiber and the polymer bond better, the fiber is preferably treated to obtain a fiber with a rough surface or a fiber with a functional group on the surface. The functional group can be any one or more of hydroxyl, carboxyl or amino.

[0035] In some embodiments of the present invention, the fibers are preferably soaked in an alkaline solution for 10 to 50 minutes, preferably 20 to 40 minutes, and then washed and dried to obtain fibers with a rough surface and activated surface hydroxyl groups and amino groups.

[0036] In some preferred embodiments of the present invention, the fiber can also carry other materials by chemical reaction, bonding, adsorption or physical wrapping. The other materials can be any one or more of drugs, tissue components or materials that promote tissue growth. Among them, the drugs can be selected from triclosan, silver powder, etc. with anti-inflammatory effects or chitosan, etc. with hemostatic effects, the tissue components can be selected from hydroxyapatite, etc., and the materials that promote tissue growth can be selected from bone regeneration, hydroxy calcium phosphate or tricalcium phosphate, etc.

[0037] The present invention also provides a method for preparing the above-mentioned fiber-reinforced polymer, comprising the following steps: The monomer melt or monomer prepolymer melt is placed in the gap between fibers, and a polymerization reaction occurs under the action of a catalyst to obtain a fiber-reinforced polymer.

[0038] In the present invention, the catalyst is selected from any one or more of a tin catalyst, a stannous catalyst or a zinc catalyst; the polymerization reaction temperature is 100-180°C, preferably 120-150°C; the reaction time is more than 1 h, preferably 12-48 h; the pressure is -0.1-20 MPa, preferably 0.05-10 MPa.

[0039] In the present invention, the polymerization reaction is preferably carried out in an inert atmosphere or in vacuum.

[0040] In the present invention, the polymerization reaction may be homopolymerization, copolymerization of two monomers, or copolymerization of multiple monomers. The reaction equipment of the polymerization reaction may have a vacuum or ultrasonic function, and the monomer melt or monomer prepolymer melt containing the catalyst may flow into the gaps between the fibers through vacuum degassing or ultrasonic degassing. The reaction equipment may also pressurize the monomer melt or monomer prepolymer melt into the fibers through pressure.

[0041] In the present invention, the reaction equipment of the polymerization reaction can determine the arrangement of fibers, the internal shape of the reaction equipment and the necessary tooling according to product requirements. In addition, in the actual production process, considering whether the polymer after the reaction can be taken out smoothly, the reaction equipment should have a taper, and the inner surface should be made of a material that does not adhere to the polymer, such as polytetrafluoroethylene.

[0042] In some specific embodiments of the present invention, the fiber-reinforced polymer is preferably prepared according to the following steps: (1) Clean and dry the prepolymerization kettle (with stirring) and the polymerization kettle (without stirring, without bottom valve, with taper, lined with polytetrafluoroethylene) in advance, and replace the nitrogen with vacuum. Add the polymerization monomer to the prepolymerization kettle, control the temperature, add the catalyst, stir, and then introduce it into the polymerization kettle; (2) The polymerization kettle is preheated to the target temperature in advance. Multiple 304 stainless steel frames can be inserted into the polymerization kettle in parallel. After the fibers are wrapped around the surface of the 304 stainless steel frames, vacuum is evacuated and filled with nitrogen 2 to 3 times. Finally, the polymerization is carried out at 0.05 to 0.06 MPa of nitrogen for 12 to 48 hours, preferably 24 to 36 hours. After cooling, the lid of the kettle is opened to obtain a fiber-reinforced polymer. The fiber-reinforced polymer is in block form.

[0043] In some specific embodiments of the present invention, the above step (2) is as follows: insert a polytetrafluoroethylene tooling into the kettle, open a through hole on the tooling, insert the fiber into the hole, and seal the two sides with a porous plate to prevent the fiber from leaking out. Turn on the ultrasonic vibration degassing for 5-10 minutes, and polymerize at a nitrogen pressure of 0.05-0.06 MPa for 12-48 hours, preferably 24-36 hours. After cooling, open the kettle cover to obtain a fiber-reinforced polymer. The fiber-reinforced polymer is in the shape of a rod.

[0044] In this solution, the inserted fibers are long fibers with a length ranging from 15 to 50 mm, such as 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm or 50 mm.

[0045] It should be noted that the polymerization method adopted in the present invention does not necessarily require that the fiber composite material has a certain fluidity. Therefore, long fibers can be used. Compared with short fibers with low content and random distribution, the content of long fibers in the present technical solution can not only be higher, but the fibers can be distributed in directions and stereostructures. Therefore, the product not only has high overall strength, but also can optimize the strength in each stereo direction according to the different mechanical requirements of the product in each direction, thereby maximizing the mechanical properties of the material.

[0046] In some specific embodiments of the present invention, the above step (2) is: insert a 304 stainless steel plate into the kettle, adjust the gap between the two steel plates by screws, clamp the fiber cloth, and pad a polytetrafluoroethylene membrane in the steel plate to facilitate the removal of the fiber cloth reinforced polymer. After the material is introduced into the polymerization kettle, open the vacuum, fill with nitrogen, repeat multiple times, turn on the ultrasonic vibration degassing, each time for 1 to 10 minutes, and repeat multiple times. Finally, polymerize under vacuum for 12 to 48 hours, preferably 24 to 36 hours. After cooling, open the kettle cover to obtain the fiber-reinforced polymer. The fiber-reinforced polymer is in block form.

[0047] In other specific embodiments of the present invention, the fiber-reinforced polymer is preferably prepared according to the following steps: In the heating stirring kettle and polymerization equipment (composed of two plates, the upper and lower plates can be heated at a controlled temperature, and the upper and lower plates have semi-cylindrical grooves with a length of 300 mm and a diameter of 10 mm facing each other, and the two ends of the upper groove are respectively connected to the stirring kettle and the vacuum pump. There is a silicone rubber sealing strip between the upper and lower plates to ensure the sealing of the polymerization device). The stirring kettle and the polymerization device are cleaned and dried in advance, and the nitrogen is replaced by vacuum. The monomer is added to the stirring kettle, and the catalyst is added after the temperature is controlled and stirred. The polymerization device is preheated to the target temperature in advance. The upper and lower grooves of the polymerization device are sandwiched with PGLA9010 fiber woven cloth reels (β-tricalcium phosphate powder is evenly sprinkled on the PGLA9010 fiber cloth and rolled up tightly, the fiber cloth weighs 18.4 g, and β-tricalcium phosphate weighs 2.8 g). The heating stirring kettle is added with 3 atmospheres of pressure, and the vacuum pump of the polymerization device is turned on until the melt of the polymerization monomer flows out of the vacuum port, the polymerization device is closed, and after the polymerization reaction is completed, it is cooled, and the upper plate of the polymerization device is opened to obtain a fiber-reinforced polymer. The fiber-reinforced polymer is in the shape of a rod. In the present invention, the strength of the final product depends largely on the fiber strength, fiber content, and the bonding strength between the polymer and the fiber. Therefore, under the premise that the fiber strength and the bonding strength between the fiber and the polymer are determined, the higher the fiber content, the higher the strength of the product. In the present invention, the mass content of the fiber in the fiber-reinforced polymer can reach 10-90%, preferably 30-90%.

[0048] According to tests, the weight average molecular weight of the fiber-reinforced polymer is 10,000 to 800,000 Da.

[0049] It can be seen that the preparation method of the fiber-reinforced polymer provided by the present invention is to place the fiber in a polymerization device, and the molten reaction monomer or prepolymer penetrates into the gap between the fibers for polymerization to obtain the fiber-reinforced polymer. Therefore, the preparation method is a fiber-reinforced polymer material obtained by chemical reaction, which has the following advantages over traditional physical methods: (1) One-step polymerization, simpler steps and lower cost; (2) By infiltrating the molten reactive monomer or prepolymer into the fiber for polymerization, the bonding strength between the fiber and the polymer can be made higher; (3) The fibers can be arranged in an orderly manner and pre-stressed to further balance the various properties of the fiber-reinforced polymer.

[0050] The present invention also provides a fracture internal fixation product obtained by machining the fiber-reinforced polymer, wherein the fracture internal fixation product comprises a bone plate, a bone nail, a bone screw or a bone fixation rod.

[0051] In some embodiments of the present invention, the obtained fiber-reinforced polymer can be placed on a machining device to mill out an absorbable bone plate or turn into an absorbable bone screw. The present invention also does not specifically limit the specifications of the absorbable bone plate and the absorbable bone screw, and they can be prepared according to actual needs.

[0052] According to the test, the bending strength of the fracture internal fixation product is above 100 MPa, and the bending modulus is above 2500 MPa. When the fracture internal fixation product is a bone screw, the maximum torque is above 50 N / mm.

[0053] In summary, the present invention uses fibers as reinforcing ribs, obtains fiber-reinforced polymers through a polymerization method, and finally undergoes machining to obtain a fracture internal fixation product with excellent mechanical properties.

[0054] In order to further illustrate the present invention, the following examples are provided for detailed description. The experimental raw materials used in the following examples of the present invention are all common commercially available products.

[0055] Example 1 This embodiment provides a fiber-reinforced absorbable bone plate, and the preparation method is as follows: The 5 L prepolymerization kettle (with stirring) and the polymerization kettle (without stirring, without bottom valve, with taper, lined with polytetrafluoroethylene) were cleaned and dried in advance, and the nitrogen was replaced by vacuum. 3 Kg of polymerization-grade L-lactide was added to the prepolymerization kettle, and the temperature was controlled at 120°C. 0.05% (mass ratio) of stannous octoate catalyst was added, stirred for 5 min, and introduced into the polymerization kettle. The polymerization kettle was preheated to 120°C in advance, and 24 304 stainless steel frames were inserted in parallel in the kettle. The frame spacing was 20 mm, and the frame length, width and thickness were 70*25*0.5 mm (the rectangular size in the frame was 50*20*0.5 mm). Four were grouped together, and carbon fiber, stereo polylactic acid fiber and surface-treated stereo polylactic acid fiber (stereo polylactic acid surface treatment method: 0.1 mol / L sodium hydroxide solution was soaked at room temperature for 20 min, purified water ultrasonic cleaning 3 times, and vacuum dried at 40°C for 8 h before use) were 0.63 g each. Vacuum and fill with nitrogen three times, and finally fill with nitrogen at 0.05 MPa for polymerization for 36 hours. Cool for 24 hours, open the lid of the kettle, and take out the polymer block. Put it on the machining equipment, and mill out a four-hole, 3.5 mm thick absorbable bone plate with the stainless steel frame as the center. The blank sample is the absorbable bone plate processed outside the stainless steel frame.

[0056] The weight average molecular weight of the test polymer block is 380,000 Daltons, and the number average molecular weight is 240,000 Daltons. The bending strength and bending modulus of the test fiber reinforced absorbable bone plate are shown in Table 1 below.

[0057] Table 1

[0058] As can be seen from Table 1, the fiber-reinforced materials with the same mass of carbon fiber, stereopolymeric polylactic acid fiber, and surface-treated stereopolymeric polylactic acid fiber added during polymerization, the bending strength of the absorbable bone plate obtained by machining is more than 2 times higher than that of the poly-L-lactide bone plate without fiber reinforcement (i.e., blank sample), and the bending modulus is more than 1.5 times higher. At the same time, the bending strength and bending modulus of the absorbable bone plate are also improved when the prestress is increased from 2 N to 20 N. Under the same added mass and the same prestress, the order of the bending strength and modulus of the absorbable bone plate is: carbon fiber > surface-treated stereopolymeric polylactic acid fiber > stereopolymeric polylactic acid fiber.

[0059] Example 2 This embodiment provides a fiber-reinforced absorbable bone nail, and the preparation method is as follows: The 5 L prepolymerization kettle (with stirring) and the polymerization kettle (without stirring, without bottom valve, with taper, lined with polytetrafluoroethylene, connected to a 700 W, 25 KHz ultrasonic vibrator) were cleaned and dried in advance, and the nitrogen was replaced by vacuum. A total of 3 kg of polymerization-grade L-lactide and glycolide were added to the prepolymerization kettle, with a molar ratio of 75:25. The temperature was controlled at 120°C, and 0.05% (mass ratio) of stannous octoate catalyst was added, stirred for 5 min, and introduced into the polymerization kettle. The polymerization kettle was preheated to 120°C in advance. A polytetrafluoroethylene tooling was inserted into the kettle, with 27 holes opened on the tooling, with a hole diameter of 10 mm and a length of 50 mm. Three were grouped, one group was blank, four groups were filled with flax fibers, and four groups were filled with carbon fibers. The flax fibers with a length of 15 mm were 0.79 g, 1.57 g, 2.16 g, and 2.75 g (corresponding to fiber content: 0.2 g / cm 3 , 0.4 g / cm 3 , 0.55 g / cm 3 , 0.70 g / cm 3 The fiber content refers to the mass of fiber per cubic centimeter of polymer volume). The two sides are sealed with a 1 mm diameter porous plate to prevent fiber leakage. The carbon fibers with a length of 15 mm are respectively 0.79 g, 1.57 g, 2.16 g, and 2.75 g (corresponding to a fiber content of 0.2 g / cm 3 , 0.4 g / cm 3 , 0.55 g / cm 3 、0.70g / cm 3Fiber content refers to the mass of fiber per cubic centimeter of polymer volume). The two sides were sealed with a 1 mm diameter porous plate to prevent fiber leakage. Ultrasonic vibration degassing was turned on for 5 min, and polymerization was carried out under a nitrogen pressure of 0.05 MPa for 36 h. Cooling for 24 h, the lid of the kettle was opened, and the fiber-reinforced polymer profile rod was taken out. The fiber-reinforced polymer profile rod taken out by machining was turned into an absorbable bone screw with a diameter of 4.5 mm and a length of 35 mm.

[0060] The weight average molecular weight of the test polymer block is 180,000 Daltons, and the number average molecular weight is 110,000 Daltons. The bending strength and bending modulus of the test absorbable bone screws are shown in Table 2 below.

[0061] Table 2

[0062] As can be seen from Table 2, when 15 mm long fibers were added during the polymerization of PLGA (75:25), the bending strength and bending modulus of the absorbable bone screws processed increased with the increase of fiber content, and the fiber content reached 0.7 g / cm 3 The flexural strength and flexural modulus of flax fiber are 2.6 times and 1.9 times of the blank sample, respectively, and the flexural strength and flexural modulus of carbon fiber are 3.2 times and 2.1 times of the blank sample, respectively. At the same time, it can be seen that when adding the same mass of carbon fiber and flax fiber, the absorbable bone screw made with carbon fiber has higher flexural strength and flexural modulus, with a content of 0.7 g / cm 3 The flexural strength and flexural modulus of carbon fiber are 1.2 times and 1.1 times that of flax fiber respectively.

[0063] In conventional extrusion and injection molding processes, the maximum amount of long fibers mixed is 30 g / 100 cm 3 The polymerization method adopted by the present invention has very low molecular weight of prepolymer, very good fluidity, and can easily penetrate into the gap between fibers, so the fiber content can be higher and the product strength can be higher.

[0064] Example 3 This embodiment provides a fiber-reinforced absorbable bone plate, and the preparation method is as follows: The 5 L prepolymerization kettle (with stirring) and the polymerization kettle (without stirring, without bottom valve, with taper, lined with polytetrafluoroethylene, connected to a 700 W, 25 KHz ultrasonic vibrator) were cleaned and dried in advance, and the nitrogen was replaced by vacuum. A total of 3 kg of polymerization-grade L-lactide and DL-lactide were added to the prepolymerization kettle with a molar ratio of 92:8. The temperature was controlled at 120°C, and 0.05% (mass ratio) of stannous octoate catalyst was added. After stirring for 5 min, it was introduced into the polymerization kettle. The polymerization kettle was preheated to 120°C in advance, and two 4 mm thick 304 stainless steel plates were inserted into the kettle. The gap between the two steel plates was adjusted by screws, and 5 layers of carbon fiber fabric were clamped (T300 carbon fiber fabric produced by Toray Corporation of Japan, with 3 K plain weave and surface density of 216 g / cm 2 ), in order to facilitate the removal of the carbon fiber cloth reinforced polymer, a polytetrafluoroethylene membrane is placed inside the steel plate. After the material is introduced into the polymerization kettle, the vacuum is turned on, nitrogen is filled, and the process is repeated many times. The ultrasonic vibration degassing is turned on for 4 minutes each time and repeated many times. Finally, the polymerization is carried out under vacuum for 36 hours. Then, it is cooled for 24 hours, the lid of the kettle is opened, and the polymer block is taken out. The polymer block taken out by machining is milled into an absorbable bone plate with 4 holes and a thickness of 3.5 mm. From the appearance, it can be seen that the carbon fiber fabric is completely infiltrated into the polymer.

[0065] The weight average molecular weight of the test polymer is 100,000 Daltons, the number average molecular weight is 60,000 Daltons, and the carbon fiber content in the test polymer is 88 wt%.

[0066] The bending strength and bending modulus data of the absorbable bone plate are shown in Table 3 below.

[0067] Table 3

[0068] Example 4

[0069] This embodiment provides a fiber-reinforced absorbable bone nail, and the preparation method is as follows: The 5 L prepolymerization kettle (with stirring) and the polymerization kettle (without stirring, without bottom valve, with taper, lined with polytetrafluoroethylene, connected with 700 W, 25 KHz ultrasonic vibrator) were cleaned and dried in advance, and the nitrogen was replaced by vacuum. 3 kg of polymerization-grade L-lactide was added to the prepolymerization kettle, and the temperature was controlled at 115 ° C. 0.03% (mass ratio) of stannous octoate catalyst was added, stirred for 5 min, and introduced into the polymerization kettle. The polymerization kettle was preheated to 115 ° C in advance. A polytetrafluoroethylene tooling was inserted into the kettle, and 4 holes were opened on the tooling. The hole size was 10 mm in diameter and 50 mm in length. PGLA (90:10) braid containing hydroxyapatite was inserted (PGLA weighed 2.8 g, hydroxyapatite weighed 0.47 g, and layers of braids were put together, and hydroxyapatite was sandwiched between the layers). Ultrasonic vibration degassing was turned on for 5 min, vacuum degassing was performed for 5 min, and ultrasonic was performed for 5 min. Polymerization was carried out under a nitrogen pressure of 0.05 MPa for 36 h. After cooling for 24 h, the lid of the autoclave was opened and the polymer block was taken out. The polymer block was machined into an absorbable hollow bone screw with a diameter of 4.5 mm, a length of 35 mm, and an inner hole of 1.5 mm.

[0070] The weight average molecular weight of the tested polymer block is 180,000 Daltons, and the number average molecular weight is 110,000 Daltons. The mechanical properties of the tested hollow absorbable bone screws are shown in Table 4 below.

[0071] Table 4

[0072] Example 5 This embodiment provides a fiber-reinforced absorbable bone nail, and the preparation method is as follows: The 2 L heated stirring kettle and polymerization equipment (composed of two plates, the upper and lower plates can be heated at controlled temperature, the upper and lower plates have semi-cylindrical grooves with a length of 300 and a diameter of 10 mm facing each other, and the two ends of the upper groove are connected to the stirring kettle and the vacuum pump respectively. The upper and lower plates are directly provided with silicone rubber sealing strips to ensure the sealing of the polymerization device). Clean and dry in advance, and replace the stirring kettle and polymerization device with nitrogen in vacuum. Add 1 kg of polymerization-grade L-lactide to the stirring kettle, control the temperature at 110℃, add 0.05% (mass ratio) of stannous octoate catalyst, and stir for 5 min. Preheat the polymerization device to 120℃ in advance. The PGLA (90:10) fiber woven cloth roll is clamped in the upper and lower grooves of the polymerization device (β-tricalcium phosphate powder is evenly sprinkled on the PGLA fiber cloth and rolled up tightly, the fiber cloth weighs 18.4 g, and β-tricalcium phosphate weighs 2.8 g). The heated stirring kettle is pressurized to 3 atmospheres, and the vacuum pump of the polymerization device is turned on until the polymerization monomer solution flows out of the vacuum port. Close the polymerization device and react at 120℃ for 24 h. After cooling for 6 h, the upper plate of the polymerization equipment was opened and the fiber-reinforced polymer rod was taken out and machined into absorbable bone screws with a diameter of 3.5 mm and a length of 30 mm.

[0073] The weight average molecular weight of the test fiber reinforced polymer profile rod is 150,000 Daltons, and the number average molecular weight is 90,000 Daltons. The PGLA fiber content of the test fiber reinforced polymer profile rod is calculated to be 65 wt%, and β-tricalcium phosphate is 10 wt%. The mechanical data of the test absorbable bone screw are shown in Table 5 below.

[0074] Table 5

[0075] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fiber-reinforced polymer, characterized in that: Obtained by polymerization of monomers or monomer prepolymers in the fiber gaps; The mass content of the fiber in the polymer is 10-90 wt%.

2. The fiber-reinforced polymer according to claim 1, characterized in that The fiber is a fiber with a rough surface or a fiber with a functional group on the surface, and the functional group is selected from any one or more of a hydroxyl group, a carboxyl group or an amino group; The fiber is subjected to stress stretching treatment, and the stress is 2-2000 N.

3. The fiber-reinforced polymer according to claim 1 or 2, characterized in that The fiber includes any one or more of monofilament fiber, multifilament fiber or fiber braid; The fiber is selected from any one or more of carbon fiber, nylon fiber, stereopolylactic acid fiber, polyglycolide fiber, plant fiber, hydroxyapatite fiber, iron carbide fiber, iron nitride fiber or metal fiber. The fibers are arranged randomly or orderly.

4. The fiber-reinforced polymer according to any one of claims 1 to 3, characterized in that The surface of the fiber is loaded with any one or more of drugs, tissue components or materials that promote tissue growth.

5. The fiber-reinforced polymer according to any one of claims 1 to 4, characterized in that The monomer is selected from any one or more of L-lactide, D-lactide, meso-lactide, glycolide, ε-caprolactone, trimethylene carbonate or p-dioxanone.

6. The fiber-reinforced polymer according to any one of claims 1 to 5, characterized in that The weight average molecular weight of the polymer is 100,000 to 800,000 Da.

7. The method for preparing a fiber-reinforced polymer according to any one of claims 1 to 6, characterized in that: The following steps are involved: The monomer melt or monomer prepolymer melt is placed in the gap between fibers, and a polymerization reaction occurs under the action of a catalyst to obtain a fiber-reinforced polymer.

8. The method for preparing a fiber-reinforced polymer according to claim 7, characterized in that: The catalyst is selected from any one or more of a tin catalyst, a stannous catalyst or a zinc catalyst; The polymerization reaction temperature is 100-180°C, the time is more than 1 h, and the pressure is -0.1-20 MPa; The polymerization reaction is carried out in an inert atmosphere or in vacuum.

9. A fracture internal fixation product, characterized in that: The fiber-reinforced polymer is obtained by machining the fiber-reinforced polymer according to any one of claims 1 to 6 or the fiber-reinforced polymer prepared by the preparation method according to claim 7 or 8.

10. The fracture internal fixation product according to claim 9, characterized in that: The bending strength of the fracture internal fixation product is above 100 MPa, and the bending modulus is above 2500 MPa; The fracture internal fixation product includes a bone plate, a bone nail, a bone screw or a bone fixation rod.

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