Polyimide implant material and preparation method thereof
By preparing polyimide implant materials, the problem of easy deformation of existing orthopedic materials under high loads has been solved, and the wear resistance and self-lubricating properties of the materials have been achieved, thus extending their service life.
Patent Information
- Application Number
- CN202511151439.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-18
- Publication Date
- 2025-10-31
AI Technical Summary
Existing orthopedic implant materials are prone to deformation under high load or variable load conditions, have a short service life, and require frequent replacement, resulting in high costs and pain.
The preparation method of polyimide implant material includes dissolving 4,4'-diaminodiphenyl ether, polyvinylidene fluoride and 3,3',4,4'-biphenyltetracarboxylic dianhydride, reacting them, end-capping and imidizing, adding carbon fibers and plasma cleaning, and finally drying and molding.
Polyimide implant materials exhibit excellent mechanical and wear resistance properties, possess self-lubricating characteristics, and their coefficient of friction decreases with increasing load. They also show superior wear resistance compared to existing materials, thus extending their service life.
Smart Images
Figure CN120860306A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of medical implant materials, specifically to a polyimide implant material and its preparation method. Background Technology
[0002] Currently, the orthopedic implant material used for joint replacement is imported highly cross-linked polyethylene. This material is mature, stable, and has been used in orthopedic implants for many years. However, its softness makes it prone to deformation under high or variable load conditions, typically resulting in a lifespan of only 6-10 years after implantation. Material failure necessitates secondary surgery, leading to increased material costs and physical discomfort. Therefore, this patented technology attempts to develop a biocompatible, non-toxic, and more wear-resistant polyimide resin material for human joint and bone replacement, potentially solving the problem of short lifespan of current materials. Summary of the Invention
[0003] To address the shortcomings of existing technologies, this invention proposes a polyimide implant material and its preparation method.
[0004] The objective of this invention can be achieved through the following technical solutions:
[0005] A first aspect of the present invention relates to a method for preparing a polyimide implant material, comprising the following steps:
[0006] Add 4,4'-diaminodiphenyl ether to the solvent, dissolve it, add polyvinylidene fluoride and mix, then add 3,3',4,4'-biphenyltetracarboxylic dianhydride to react, and then add 4-phenylacetylene phthalic anhydride to cap the reaction.
[0007] The reaction product was subjected to imidization treatment; after purification and drying, the polyimide implant material was obtained.
[0008] Optionally, the solvent is N,N'-dimethylacetamide, N,N'-dimethylformamide, or N-methylpyrrolidone.
[0009] Optionally, the reagents added during imidization include: triethylamine and acetic anhydride, pyridine and acetic anhydride, or 4-methylpyridine and acetic anhydride.
[0010] Optionally, carbon fiber is added after 4,4'-diaminodiphenyl ether and before 3,3',4,4'-biphenyltetracarboxylic dianhydride.
[0011] Optionally, the carbon fiber is 200-mesh short-cut carbon fiber.
[0012] Optionally, the carbon fibers are plasma cleaned before being added.
[0013] Optionally, the plasma cleaning includes the following steps:
[0014] Carbon fibers are placed in a plasma cleaning chamber. A vacuum pump is used to evacuate the chamber to near the ultimate vacuum. A cleaning medium is introduced to make the vacuum level in the cleaning chamber 50-100Pa. The power is turned on and the cleaning is carried out for 5 minutes at a frequency of 40kHz-13.56MHz to obtain plasma-treated fibers.
[0015] Optionally, the purification and drying process includes the following steps:
[0016] After complete imidization and precipitation of the target compound, solid-liquid separation was achieved by centrifugation. The target compound was washed and centrifuged with ethanol. The separated compound was dried in a vacuum oven at 250°C and a vacuum degree not lower than -0.095 MPa.
[0017] A second aspect of the present invention relates to a polyimide implant material prepared by the above-described method for preparing polyimide implant materials.
[0018] A third aspect of the present invention relates to the use of the above-described polyimide implant material in the preparation of artificial bones or artificial joints.
[0019] The beneficial effects of this invention are:
[0020] Compared with the prior art, the polyimide resin provided in this application has a lower powdering rate and excellent mechanical properties. Under variable load test conditions, it exhibits excellent impact and friction wear resistance, and its self-lubricating properties are demonstrated. The coefficient of friction decreases with the increase of test load, and the wear is slightly weaker than that of highly cross-linked polyethylene. It has application prospects in artificial joints and implants. Attached Figure Description
[0021] The invention will now be further described with reference to the accompanying drawings.
[0022] Figure 1 The images show carbon fibers before and after plasma cleaning. The left image shows the fibers before cleaning, and the right image shows the fibers after cleaning. The comparison clearly shows that the surface smoothness and dispersion of the cleaned carbon fibers are significantly improved.
[0023] Figure 2 This refers to the artificial joint after processing and molding as described in this application;
[0024] Figure 3 The photo shows the results of the wear test on highly cross-linked polyethylene. The test was conducted in accordance with the national standard (GB / T 3960-2016). The test data shows that the friction coefficient and wear performance of highly cross-linked polyethylene are both superior. After the variable load test, the sample has been deformed and the deformation is obvious, showing a collapsed state.
[0025] Figure 4The photos show the results of the wear test on polyetheretherketone (PEEK). PEEK has a high coefficient of friction and wear. After continuous testing, due to its severe wear, it no longer meets the requirements for a 330N test.
[0026] Figure 5 The image shows a photograph of the polyimide after wear test according to this application. After the polyimide strip test is completed, its ground joint is relatively smooth, and the coefficient of friction decreases with the extension of test time, which is consistent with its self-lubricating properties and has better wear resistance.
[0027] Figure 6 This is a schematic diagram of the spline test results in an embodiment of this application. Detailed Implementation
[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0029] Implementation Case 1
[0030] At room temperature and pressure, 20g of 4,4'-diaminodiphenyl ether (ODA) was added to a glass bottle containing 400g of N,N'-dimethylacetamide (DMAC). After the substance was completely dissolved, 2g of polyvinylidene fluoride (PVDF) was added and stirred for several minutes. Then, 29.3g of 3,3',4,4'-biphenyltetracarboxylic dianhydride was slowly added over 1 hour. The mixture was reacted in an oil bath at 60°C for 5 hours. After that, 0.2g of 4-phenylacetylene phthalic anhydride was added to end-cap the system. Subsequently, 5g of triethylamine and 22g of acetic anhydride were added to imidize the system. After complete imidization and precipitation of the target compound, solid-liquid separation was achieved by centrifugation. Finally, the target compound was washed with ethanol and centrifuged. The above operation was repeated three times to remove acetic acid, triethylamine, DMAC, and other substances from the target compound. The separated material was dried in a vacuum oven at 250°C and a vacuum level not lower than -0.095 MPa, then collected, pulverized, and its performance was tested by high-temperature molding.
[0031] Implementation Case 2
[0032] At room temperature and pressure, 18g of 4,4'-diaminodiphenyl ether (ODA) and 2g of 4,4'-diaminodiphenylmethane (MDA) were added to a glass bottle containing 400g of N,N'-dimethylformamide (DMF). After the substances were completely dissolved, 8g of graphite was added and the mixture was stirred for several minutes. Then, 29.3g of 3,3',4,4'-biphenyltetracarboxylic dianhydride was slowly added over 1 hour. The mixture was reacted in an oil bath at 60°C for 5 hours. After that, 0.2g of 4-phenylacetylene phthalic anhydride was added to end-cap the system. Subsequently, 5g of pyridine and 22g of acetic anhydride were added to imidize the system. After imidization was complete and the target compound precipitated, solid-liquid separation was achieved by centrifugation. Finally, the target compound was washed with ethanol and centrifuged. The above operation was repeated three times to remove acetic acid, pyridine, DMF, and other substances from the target compound. The separated material was dried in a vacuum oven at 250°C and a vacuum level not lower than -0.095 MPa, then collected, pulverized, and its performance was tested by high-temperature molding.
[0033] Implementation Case 3
[0034] At room temperature and pressure, 14g of 4,4'-diaminodiphenyl ether (ODA) and 4.7g of 1,4-diaminonaphthalene were added to a glass bottle containing 400g of N-methylpyrrolidone (NMP). After the substances were completely dissolved, 19g of 200-mesh short-cut carbon fibers were added and stirred for several minutes. Then, 29.3g of 3,3',4,4'-biphenyltetracarboxylic dianhydride was slowly added over 1 hour. The mixture was reacted in an oil bath at 60°C for 5 hours. After that, 0.2g of 4-phenylacetylene phthalic anhydride was added to end-cap the system. Subsequently, 5g of 4-methylpyridine and 22g of acetic anhydride were added to imidize the system. After imidization was complete and the target compound precipitated, solid-liquid separation was achieved by centrifugation. Finally, the target compound was washed with ethanol and centrifuged. The above operation was repeated three times to remove acetic acid, 4-methylpyridine, NMP, and other substances from the target compound. The separated material was dried in a vacuum oven at 250°C and a vacuum level not lower than -0.095 MPa, then collected, pulverized, and its performance was tested by high-temperature molding.
[0035] Implementation Case 4
[0036] The 200-mesh short-cut carbon fibers were processed in place of the carbon fibers described in Example 3 using the following method:
[0037] 19g of carbon fiber was placed in the plasma cleaning chamber. The chamber was evacuated to its ultimate vacuum using a vacuum pump, and a certain amount of He was introduced to maintain the vacuum level between 80-100 Pa. Then, a 13.56MHz power supply was turned on for cleaning for 5 minutes. After cleaning, the carbon fiber was immediately transferred to a reaction flask.
[0038] Other preparation methods are the same as in Example 3.
[0039] The performance of the powder prepared after successful small-scale testing of the limited cases mentioned above, and then scaled up to the same ratio, is shown in the table below after molding. The molding process was carried out using a four-column flat vulcanizing machine, with mold specifications determined by the user, pressure of 50 MPa, temperature of 400℃, and holding at temperature and pressure for 2 hours, followed by natural cooling to below 100℃ for demolding.
[0040]
[0041]
[0042] Example 5
[0043] In Example 3, 1g of silver nitrate was added before end-capping the system, and the other steps were the same as in Example 3.
[0044] Example 6
[0045] In Example 4, 1g of silver nitrate was added before the system was capped, and the other steps were the same as in Example 4.
[0046] The polyimide materials obtained in Examples 3, 5, and 6 were made into test strips of the same size and placed in 1 mL of Staphylococcus aureus suspension (approximately 1 × 10⁻⁶). 6 The antibacterial rates of the materials in Examples 3, 5, and 6 were calculated to be 5.1%, 61.2%, and 78.3%, respectively. It is evident that the addition of silver nitrate can leverage the inherent antibacterial properties of silver ions, while the plasma-cleaned carbon fiber surface reduces silver ions to nano-silver particles, promoting their adhesion to the fiber surface.
[0047] The fiber material is placed in a plasma cleaning chamber, and the chamber is evacuated to its ultimate vacuum using a vacuum pump. A cleaning medium is then introduced to maintain a vacuum level of 50-100 Pa within the chamber. Power is turned on, and the cleaning process is carried out for 5 minutes at a frequency of 40 kHz-13.56 MHz, resulting in plasma-treated fibers. Plasma cleaning effectively removes impurities from the fiber surface while also improving the surface properties of the material itself, enhancing surface wettability and adhesion. This results in good adhesion between the fibers and the polyimide resin, thus improving the overall performance of the composite material.
[0048] The polyimide material of Embodiment 4 of this application, along with two other existing materials, were used to prepare specimens. These specimens were then continuously tested for 8 hours under different loads. The test results are as follows: Figure 6 As shown.
[0049] In summary, in terms of friction coefficient and wear, highly cross-linked polyethylene has certain advantages. However, under variable load conditions, its impact wear resistance is poor, and it is prone to deformation and collapse, resulting in a shorter service life. Polyether ether ketone (PEEK) has no advantage in either friction coefficient or wear. Polyimide resin exhibits excellent impact friction and wear resistance under variable load test conditions, demonstrating its self-lubricating properties. Its friction coefficient decreases with increasing test load, and its wear is slightly weaker than that of highly cross-linked polyethylene.
[0050] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.
Claims
1. A method for preparing a polyimide implant material, characterized in that, Includes the following steps: Add 4,4'-diaminodiphenyl ether to the solvent, dissolve it, add polyvinylidene fluoride and mix, then add 3,3',4,4'-biphenyltetracarboxylic dianhydride to react, and then add 4-phenylacetylene phthalic anhydride to cap the reaction. The reaction product was subjected to imidization treatment; after purification and drying, the polyimide implant material was obtained.
2. The method for preparing the imide implant material according to claim 1, characterized in that, The solvent is N,N'-dimethylacetamide, N,N'-dimethylformamide, or N-methylpyrrolidone.
3. The method for preparing the imide implant material according to claim 1, characterized in that, The reagents added during imidization include: triethylamine and acetic anhydride, pyridine and acetic anhydride, or 4-methylpyridine and acetic anhydride.
4. The method for preparing the imide implant material according to claim 1, characterized in that, Carbon fiber is added after 4,4'-diaminodiphenyl ether and before 3,3',4,4'-biphenyltetracarboxylic dianhydride.
5. The method for preparing the imide implant material according to claim 4, characterized in that, The carbon fiber is 200 mesh short-cut carbon fiber.
6. The method for preparing the imide implant material according to claim 4, characterized in that, The carbon fiber was cleaned with plasma before being added.
7. The method for preparing the imide implant material according to claim 6, characterized in that, The plasma cleaning includes the following steps: Carbon fibers are placed in a plasma cleaning chamber. A vacuum pump is used to evacuate the chamber to near the ultimate vacuum. A cleaning medium is introduced to make the vacuum level in the cleaning chamber 50-100Pa. The power is turned on and the cleaning is carried out for 5 minutes at a frequency of 40kHz-13.56MHz to obtain plasma-treated fibers.
8. The method for preparing the imide implant material according to claim 1, characterized in that, The purification and drying process includes the following steps: After complete imidization and precipitation of the target compound, solid-liquid separation was achieved by centrifugation. The target compound was washed and centrifuged with ethanol. The separated compound was dried in a vacuum oven at 250°C and a vacuum degree not lower than -0.095 MPa.
9. A polyimide implant material prepared by the method for preparing polyimide implant materials according to any one of claims 1 to 8.
10. The use of the polyimide implant material of claim 9 in the preparation of artificial bones or artificial joints.