An antibacterial fiber and a preparation method and application thereof

Abstract

This invention discloses an antibacterial fiber, its preparation method, and its applications. The antibacterial fiber comprises ultra-high molecular weight polyethylene fiber and an antibacterial substance. The preparation method includes: preparing a spinning solution containing ultra-high molecular weight polyethylene and the antibacterial substance; extruding the spinning solution through a spinneret to obtain a spinning fluid; and subjecting the spinning fluid to a heat-stretching treatment after cooling and setting. The antibacterial fiber of this application possesses characteristics such as good antibacterial properties, good biocompatibility, and low cytotoxicity, and can be applied in medical fields such as surgical sutures, artificial joints, and bone repair materials.

Description

Technical Field

[0001] This invention relates to the field of fibers, specifically to an antibacterial fiber and its preparation method, and more specifically to an ultra-high molecular weight polyethylene antibacterial fiber, its preparation method, and its application. Background Technology

[0002] Ultra-high molecular weight polyethylene fiber, as one of the three major high-performance fibers (carbon fiber, aramid fiber, and ultra-high molecular weight polyethylene fiber), has a simple chemical structure and not only has excellent mechanical properties, abrasion resistance, bending resistance, and fatigue resistance, but also has good biocompatibility and low cytotoxicity. It can be used as a material for long-term placement in the body, such as surgical sutures, artificial joints, and bone repair.

[0003] Invention patent CN202110610853.7 discloses an antibacterial fiber material and its preparation method, which involves a solution spinning process in which antibacterial particles, a modifier, and glass microspheres are added to the spinning solution. The modifier is selected from at least one of maleic anhydride-grafted polypropylene, maleic anhydride-grafted polyethylene, maleic anhydride-grafted ethylene butyl acrylate, and maleic anhydride-grafted ethylene vinyl acetate copolymer. The fiber can be used to prepare mountaineering clothing, etc.

[0004] Invention patent ZL201880075967.2 discloses a method for preparing osteoconductive fiber products and a medical implant containing such osteoconductive fiber products. By coating the fiber surface with bioactive ceramic particles, bone growth on the product after fiber implantation is enhanced, and the bioactivity of the fiber is improved.

[0005] Invention patent CN202210089120.8 discloses a high-strength, easily sutured, non-absorbable medical suture and its preparation method. The medical suture includes a core layer and a sheath layer covering the core layer; the core layer is woven from ultra-high molecular weight polyethylene fibers; the sheath layer is a silicone rubber-based sheath layer, which can be a non-absorbent swellable sheath layer or an absorbent swellable sheath layer; the non-absorbent swellable sheath layer is methyl vinyl silicone rubber, and the absorbent swellable sheath layer is a composite of methyl vinyl silicone rubber and polyvinylpyrrolidone.

[0006] While there is already public information on the use of ultra-high molecular weight polyethylene (UHMWPE) fibers in medical materials, and various technical solutions have been proposed, such as surface grafting to impart antibacterial properties to the fiber surface; surface coating with bioactive ceramics to enhance bioactivity and promote bone growth; and the use of weaving technology, with polyethylene fiber as the core and silicone rubber as the sheath, to prepare non-absorbable sutures.

[0007] However, fiber surface treatment can easily lead to a decrease in fiber mechanical properties, or the surface coating may easily fall off or increase surface adhesion and introduce more substances, thereby affecting fiber performance. At the same time, the cost is high, which is not conducive to industrial implementation. Summary of the Invention

[0008] To address the problems existing in the prior art and improve the antibacterial properties of ultra-high molecular weight polyethylene fiber in the medical field, thereby eliminating inflammation in organisms, this invention provides an antibacterial fiber. An antibacterial agent is added during its preparation process, which can be evenly dispersed within and on the surface of the fiber, improving its antibacterial performance. Furthermore, the fiber is non-cytotoxic, safe, and stable, and can be used in implants within organisms.

[0009] One objective of this invention is to provide an antibacterial fiber, comprising ultra-high molecular weight polyethylene fiber and an antibacterial substance.

[0010] The antibacterial substance is preferably selected from at least one of cephalosporins, ofloxacin, vancomycin, ciprofloxacin, lincomycin, and fosfomycin.

[0011] The antibacterial substance has a size of 200-800 mesh, preferably 400-600 mesh.

[0012] The antibacterial substance is 2-10 wt% of ultra-high molecular weight polyethylene fiber, preferably 3-8 wt%.

[0013] The antibacterial fiber is prepared from ultra-high molecular weight polyethylene resin particles with slits or cracks on the surface having a width of 10–10000 nm. Further, the depth of the slits or cracks on the surface of the ultra-high molecular weight polyethylene resin particles is 0.01–50 μm.

[0014] The antibacterial fiber has the characteristics of antibacterial and anti-inflammatory properties, good biocompatibility, and low cytotoxicity.

[0015] The antibacterial fiber has an antibacterial rate of over 95% against pathogenic bacteria such as Escherichia coli and Staphylococcus aureus.

[0016] A second objective of this invention is to provide a method for preparing the antibacterial fiber, comprising the following steps:

[0017] a) Prepare a spinning solution containing ultra-high molecular weight polyethylene resin and antibacterial substances;

[0018] b) The spinning solution is extruded through a spinneret to obtain a spinning fluid;

[0019] c) The antibacterial fiber is obtained by curing, drying and hot stretching the spinning fluid.

[0020] The preparation of the ultra-high molecular weight polyethylene resin spinning solution in step a) includes the following steps:

[0021] a1) Disperse ultra-high molecular weight polyethylene resin in an organic solvent, add antibacterial substances, and obtain a polyethylene suspension;

[0022] a2) Pressurize the polyethylene suspension;

[0023] a3) Heat and stir the mixture to rapidly reduce the pressure to atmospheric pressure.

[0024] The ultra-high molecular weight polyethylene resin particles have slits or cracks with a width of 10 to 10,000 nm on their surface.

[0025] The depth of the slits or cracks on the surface of the ultra-high molecular weight polyethylene resin particles is 0.01 to 50 μm.

[0026] The ultra-high molecular weight polyethylene resin particles can be prepared using existing technologies or selected from commercially available products.

[0027] The surface structure characteristics of the ultra-high molecular weight polyethylene resin facilitate the formation of a uniform spinning solution. Under normal conditions, the surface of ultra-high molecular weight polyethylene resin particles is relatively dense, making it difficult for solvents to penetrate into the resin. This technical solution uses a surface with unevenness and narrow slits, cracks, or pores with a width of 10–10000 nm and a depth of 0.01–50 μm. This facilitates the penetration of solvents and added small-molecule antibacterial substances into the resin, allowing them to mix evenly and form a uniform mixed spinning solution. This improves the dispersibility of the antibacterial substances, enabling them to adhere more to the fiber interior or surface.

[0028] Meanwhile, by applying a pressure of 0.1 to 1 MPa, preferably 0.15 to 0.8 MPa, to the ultra-high molecular weight polyethylene turbid liquid, it is further ensured that the solvent and small molecules can diffuse into the resin through the slits or cracks; by increasing the pressure and then suddenly decreasing the pressure, trace impurities in the slits are expelled, which is beneficial to the purification of the resin before spinning.

[0029] The added antibacterial substances include one or a mixture of antibacterial substances such as cephalosporins, ofloxacin, vancomycin, ciprofloxacin, lincomycin, and fosfomycin.

[0030] The antibacterial substance is not limited to the antibacterial substances mentioned above; other antibacterial substances that can exist stably in the polyethylene solution spinning system are also acceptable.

[0031] The antibacterial substance is in powder form with a size of 200-800 mesh.

[0032] Preferably, the antibacterial powder has a size of 400-600 mesh.

[0033] The mass of the antibacterial substance is 2 to 10% of the mass of the ultra-high molecular weight polyethylene resin.

[0034] Preferably, the mass of the antibacterial substance is 3 to 8% of the mass of the ultra-high molecular weight polyethylene resin.

[0035] The viscosity-average molecular weight of the ultra-high molecular weight polyethylene resin is 4 million to 8 million.

[0036] The organic solvent is one or more of the following: paraffin, mineral oil, kerosene, toluene, xylene, decahydronaphthalene, and tetrahydronaphthalene.

[0037] According to a preferred embodiment of the present invention, step a) includes:

[0038] a1) Disperse ultra-high molecular weight polyethylene resin into a container containing organic solvent to prepare an ultra-high molecular weight polyethylene suspension with a mass fraction of 6-15%, and add antibacterial substances.

[0039] a2) Gas is introduced into the container of ultra-high molecular weight polyethylene suspension and pressurized to a constant pressure of 0.1 MPa-1.0 MPa, preferably 0.15 MPa-0.8 MPa;

[0040] a3) Heat the ultra-high molecular weight polyethylene suspension to 30-60°C and stir for 30-240 minutes, then the pressure inside the container drops sharply to atmospheric pressure.

[0041] Step b) involves extruding the ultra-high molecular weight polyethylene spinning solution through a spinneret to obtain a spinning fluid.

[0042] When step a) uses a volatile solvent to prepare the ultra-high polyethylene fiber spinning solution, the curing and drying in step c includes the following steps:

[0043] c1) The spinning fluid is cooled and solidified into nascent filament by one or a combination of gas and liquid phases;

[0044] c2) The nascent filaments are treated by removing the solvent through at least one of the following methods: ring blowing, side blowing, and tunnel blowing, to obtain solid filaments.

[0045] When step a) uses a non-volatile solvent to prepare the ultra-high molecular weight polyethylene spinning solution, the curing and drying in step c includes the following steps:

[0046] c1') The spinning fluid enters the extraction tank for extraction to obtain wet precursor fibers. The extraction tank contains volatile extractants such as alkane or haloalkanes to remove organic solvents from the spinning stream.

[0047] c2') The wet raw silk is processed by at least one of the following methods to remove the extractant, namely ring blowing, side blowing, and tunnel blowing, to obtain solid silk.

[0048] The atmosphere of the annular airflow, side airflow, and tunnel airflow is selected from nitrogen, carbon dioxide, and air, and the air temperature is 30-90℃.

[0049] The thermal stretching process used in step c) includes at least two stages of stretching.

[0050] The aforementioned at least two-stage drawing includes a first drawing at 140–145°C with a drawing ratio of 3–6 times, and a second drawing at 144–148°C with a drawing ratio of 1.1–2.0 times.

[0051] The hot stretching treatment may further include three stages of stretching, preferably including a first stretching at 140-145°C with a stretching ratio of 3-6 times; a second stretching at 144-148°C with a stretching ratio of 1.1-2.0 times; and a third stretching at 143-147°C with a stretching ratio of 1.01-1.5 times.

[0052] The aforementioned at least two-stage stretching, including the first stretching, the second stretching, etc., can be continuous stretching or intermittent stretching.

[0053] This method not only leverages the high strength and high modulus of ultra-high molecular weight polyethylene fibers, but also enhances their antibacterial properties.

[0054] A third objective of this invention is to provide the antibacterial fiber or the antibacterial fiber obtained by the preparation method for use in surgical sutures or artificial joints.

[0055] The antibacterial fibers are prepared into surgical sutures for bone suturing using methods commonly found in the art. These sutures possess antibacterial properties, promoting tissue antibacterial activity and healing at the wound site, and reducing the risk of infection.

[0056] The surgical suture has an antibacterial rate of over 95% against pathogenic bacteria such as Escherichia coli and Staphylococcus aureus.

[0057] Artificial joints made from the antibacterial fibers are used as joint replacements and repair products.

[0058] The artificial joint has an antibacterial rate of over 95% against pathogenic bacteria such as Escherichia coli and Staphylococcus aureus.

[0059] In summary, the method for preparing antibacterial fibers provided by this technical solution is simple, has a short process, and meets the requirements of industrialization. The fibers obtained by this technical solution have antibacterial properties, and the fibers and related products are non-cytotoxic, safe, and stable, and can be used in biological implants. Attached Figure Description

[0060] Figure 1This is an electron microscope image of the ultra-high molecular weight polyethylene resin used in this embodiment of the technical solution. Detailed Implementation

[0061] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0062] Unless otherwise specified, the raw materials used in the examples and comparative examples are all publicly available in the prior art, such as those that can be directly purchased or prepared according to publicly available methods. The ultra-high molecular weight polyethylene resin used in the examples was selected from commercially available ultra-high molecular weight polyethylene resin from Beijing Yanshan Petrochemical Co., Ltd.

[0063] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following, in conjunction with preferred embodiments, details the preparation method of antibacterial ultra-high molecular weight polyethylene fiber and the polyethylene fiber according to the present invention, including their specific implementation methods, structures, features, and effects. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0064] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships, such as one and / or two. Specifically, it can mean that one and two can be included at the same time, one can exist alone, or two can exist alone, and any one of the above three situations can be met.

[0065] Antimicrobial performance testing standards and methods: Tests were conducted in accordance with GB / T31713-2015 "Safety and Hygiene Requirements for Antimicrobial Textiles".

[0066] Example 1

[0067] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 4 million and surface slits with a width of 1000–10000 nm and a depth of 10–50 μm was dispersed in decahydronaphthalene (UHMWPE mass percentage was 10%). 200-mesh cephalosporin (6% by mass of UHMWPE resin) was added, and the mixture was pressurized to 0.15 MPa and stirred while being heated to 60°C and maintained for 240 min. The pressure was then rapidly reduced to atmospheric pressure. The resulting UHMWPE-cephalosporin-decahydronaphthalene turbidity was mixed and dissolved using a twin-screw extruder, pumped by a booster pump, metered by a metering pump, and then extruded through a spinneret to obtain spun yarns. The spun yarns entered a hot air duct to remove the solvent (the duct air was 60°C nitrogen) to obtain dry yarns. The dry filaments were sequentially subjected to a first-stage draw at 140℃ and 4 times the strength of the first stage; a second-stage draw at 144℃ and 1.4 times the strength of the second stage; and a third-stage draw at 144℃ and 1.2 times the strength of the third stage, finally yielding ultra-high molecular weight polyethylene fibers. The fibers have a breaking strength of 41 cN / dtex, an initial modulus of 1700 cN / dtex, and contain 5.9% cephalosporin particles. Surgical sutures made from these fibers exhibited an antibacterial rate of 95.5% against Escherichia coli and 95.4% against Staphylococcus aureus, meeting medical requirements.

[0068] Example 2

[0069] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 6 million and surface slits with a width of 10–100 nm and a depth of 1–50 μm was dispersed in decahydronaphthalene (7% by mass of UHMWPE). After swelling, cephalosporin with a size of 800 mesh (8% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred while being heated to 30 °C and maintained for 240 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE-cephalosporin-decahydronaphthalene turbid liquid was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a hot air duct to remove the solvent (the duct air was 90 °C nitrogen) to obtain dry yarn. The dry filaments were sequentially subjected to a first-stage draw at 140℃ and 5.5 times the strength of the original material; a second-stage draw at 147℃ and 1.8 times the strength of the original material; and a third-stage draw at 144℃ and 1.1 times the strength of the original material, finally yielding ultra-high molecular weight polyethylene fibers. The fibers exhibit a breaking strength of 43 cN / dtex, an initial modulus of 1800 cN / dtex, and contain 6.5% cephalosporin particles. Surgical sutures made from these fibers demonstrate an antibacterial rate of 98.5% against Escherichia coli and 98.4% against Staphylococcus aureus, meeting medical requirements.

[0070] Example 3

[0071] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 8 million and surface slits with a width of 10–1000 nm and a depth of 1–50 μm was dispersed in decahydronaphthalene (UHMWPE mass percentage was 8%). After swelling, vancomycin with a size of 800 mesh (10% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60 °C and maintained for 100 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE vancomycin decahydronaphthalene turbid liquid was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a hot air duct to remove the solvent (the duct air was 80 °C nitrogen) to obtain dry yarn. The dry yarn was then subjected to a first-stage draw at 142 °C and 5 times the strength of the first stage; a second-stage draw at 147 °C and 1.5 times the strength of the second stage; and a third-stage draw at 144 °C and 1.1 times the strength of the second stage, finally yielding UHMWPE fibers. The fiber has a breaking strength of 44 cN / dtex and an initial modulus of 1900 cN / dtex. It contains 6.6% vancomycin particles. Surgical sutures made from this fiber have an antibacterial rate of 99.9% against Escherichia coli and 99.9% against Staphylococcus aureus, meeting medical requirements.

[0072] Example 4

[0073] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 5.8 million and surface slits with a width of 50–1000 nm and a depth of 1–50 μm was dispersed in decahydronaphthalene (7% by mass of UHMWPE). After swelling, clindamycin with a size of 400 mesh (7% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60 °C and maintained for 30 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE clindamycin decahydronaphthalene turbid liquid was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a hot air duct to remove the solvent (the duct air was 90 °C nitrogen) to obtain dry yarn. The dry yarn was then subjected to a first-stage draw at 142 °C and 5 times the strength of the first stage; a second-stage draw at 147 °C and 1.5 times the strength of the second stage; and a third-stage draw at 144 °C and 1.1 times the strength of the second stage, finally yielding UHMWPE fibers. The fiber has a breaking strength of 41 cN / dtex and an initial modulus of 1700 cN / dtex. It contains 6.1% clindamycin. Surgical sutures made from this fiber have an antibacterial rate of 97.8% against Escherichia coli and 97.1% against Staphylococcus aureus, meeting medical requirements.

[0074] Example 5

[0075] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 5.8 million and surface slits with a width of 50–1000 nm and a depth of 1–50 μm was dispersed in white oil (UHMWPE mass percentage was 8%). After swelling, 400-mesh cephalosporin (8% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60°C and maintained for 30 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE cephalosporin white oil turbidity was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a chloroform extraction tank to remove the white oil solvent, and then dried in a 60°C vapor phase hot box to obtain dry yarn. The dry yarn was then subjected to a first-stage draw at 140°C and 5.5 times the strength of the fiber; a second-stage draw at 147°C and 1.8 times the strength of the fiber; and a third-stage draw at 144°C and 1.1 times the strength of the fiber, finally yielding UHMWPE fiber. The fiber has a breaking strength of 41 cN / dtex and an initial modulus of 1750 cN / dtex. It contains 6.3% cephalosporin. Surgical sutures made from this fiber have an antibacterial rate of 98.0% against Escherichia coli and 98.0% against Staphylococcus aureus, meeting medical requirements.

[0076] Example 6

[0077] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 5.8 million and surface slits with a width of 50–1000 nm and a depth of 1–50 μm was dispersed in xylene (UHMWPE mass percentage was 8%). After swelling, cephalosporin with a size of 400 mesh (8% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60°C and maintained for 30 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE-cephalosporin-xylene turbidity was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a side-blowing air system (110°C nitrogen gas) to remove the solvent, resulting in dry yarn. The dry yarn was then subjected to a first-stage draw at 140°C and 5.5 times the strength of the spun yarn; a second-stage draw at 147°C and 1.8 times the strength of the spun yarn; and a third-stage draw at 144°C and 1.1 times the strength of the spun yarn, finally yielding UHMWPE fibers. The fiber has a breaking strength of 41 cN / dtex and an initial modulus of 1700 cN / dtex. It contains 6.2% cephalosporin particles. Surgical sutures made from this fiber have an antibacterial rate of 98.5% against Escherichia coli and 98.4% against Staphylococcus aureus, meeting the requirements for medical use.

[0078] Example 7

[0079] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 5.8 million and surface slits with a width of 50–1000 nm and a depth of 1–50 μm was dispersed in toluene (UHMWPE mass percentage was 8%). After swelling, cephalosporin with a size of 400 mesh (8% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60°C and maintained for 30 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE-cephalosporin-toluene turbidity was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a circulating air exchange to remove the solvent (circular air was 80°C) to obtain dry yarn. The dry yarn was then subjected to a first-stage draw at 140°C and 5.5 times the strength of the filament; a second-stage draw at 147°C and 1.8 times the strength of the filament; and a third-stage draw at 144°C and 1.1 times the strength of the filament, finally yielding UHMWPE fiber. The fiber has a breaking strength of 42 cN / dtex and an initial modulus of 1750 cN / dtex. It contains 6.2% cephalosporin particles. Surgical sutures made from this fiber have an antibacterial rate of 98.1% against Escherichia coli and 98.0% against Staphylococcus aureus, meeting medical requirements.

[0080] Example 8

[0081] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 5.8 million and surface slits with a width of 50–1000 nm and a depth of 1–50 μm was dispersed in kerosene (UHMWPE mass percentage was 8%). After swelling, cephalosporin with a size of 400 mesh (8% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60°C and maintained for 30 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE cephalosporin kerosene turbidity was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a dichloromethane extraction tank to remove kerosene, and then dried in a 39°C vapor phase hot box to obtain dry yarn. The dry yarn was then subjected to a first-stage draw at 140°C and 5.5 times the strength of the kerosene; a second-stage draw at 147°C and 1.8 times the strength of the kerosene; and a third-stage draw at 144°C and 1.1 times the strength of the kerosene, finally yielding UHMWPE fibers. The fiber has a tensile strength of 41 cN / dtex and an initial modulus of 1700 cN / dtex. It contains 6.1% cephalosporin. When artificial joints are made from this fiber, the joints have an antibacterial rate of 95.5% against Escherichia coli and 95.5% against Staphylococcus aureus, which meets the requirements for medical use.

[0082] Example 9

[0083] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 5.8 million and surface slits with a width of 50–1000 nm and a depth of 1–50 μm was dispersed in mineral oil (UHMWPE mass percentage was 8%). After swelling, cephalosporin with a size of 400 mesh (8% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60°C and maintained for 30 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE-cephalosporin-mineral oil turbidity was mixed and dissolved in a twin-screw extruder, pumped by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered a chloroform extraction tank to remove mineral oil, and then dried in a 60°C vapor phase hot box to obtain dry yarn. The dry yarn was then subjected to a first-stage draw at 143°C and 6 times the strength of the first stage; and a second-stage draw at 147°C and 1.2 times the strength of the second stage, finally yielding UHMWPE fibers. The fiber has a tensile strength of 43 cN / dtex and an initial modulus of 1800 cN / dtex. It contains 6.0% cephalosporin. When artificial joints are made from this fiber, the joints have an antibacterial rate of 95.0% against Escherichia coli and 95.2% against Staphylococcus aureus, which meets the requirements for medical use.

[0084] Example 10

[0085] Ultra-high molecular weight polyethylene (UHMWPE) resin with a viscosity-average molecular weight of 5.8 million and surface slits with a width of 50–1000 nm and a depth of 1–50 μm was dispersed in tetrahydronaphthalene (UHMWPE mass percentage was 8%). After swelling, cephalosporin with a size of 400 mesh (8% by mass of UHMWPE resin) was added. The mixture was pressurized to 0.8 MPa and stirred, heated to 60 °C and maintained for 30 min. Then, the pressure was rapidly reduced to atmospheric pressure. The resulting UHMWPE-cephalosporin-tetrahydronaphthalene mixture and turbid liquid were mixed and dissolved in a twin-screw extruder, conveyed by a booster pump and metered by a metering pump, and then extruded through a spinneret to obtain a spun yarn. The spun yarn entered an ethanol extraction tank to remove the tetrahydronaphthalene and was then dried in a 78 °C gas-phase hot oven to obtain dry yarn. The dry filaments were sequentially subjected to a first-stage draw at 141℃ (6 times the original strength), a second-stage draw at 147℃ (2.0 times the original strength), and a third-stage draw at 146℃ (1.2 times the original strength), ultimately yielding ultra-high molecular weight polyethylene fibers. The fibers exhibited a breaking strength of 41 cN / dtex, an initial modulus of 1700 cN / dtex, and contained 6.3% cephalosporin. Artificial joints made from these fibers demonstrated an antibacterial rate of 96.5% against Escherichia coli and 95.9% against Staphylococcus aureus, meeting medical requirements.

[0086] Comparative Example 1

[0087] According to Example 4, without adding any antibacterial substances and keeping other conditions unchanged, the resulting fiber composition is 100% ultra-high molecular weight polyethylene, with an ash content of 0, a tensile strength of 45 cN / dtex, and an initial modulus of 2000 cN / dtex. Surgical sutures prepared using this fiber have an antibacterial rate of 0 against Escherichia coli and an antibacterial rate of 0 against Staphylococcus aureus.

[0088] Comparative Example 2

[0089] According to Example 4, the difference is that the polyethylene suspension was only heated to 60°C under normal pressure and maintained for 30 minutes, while other conditions remained unchanged. The resulting fiber had a breaking strength of 40 cN / dtex, an initial modulus of 1600 cN / dtex, and contained 1.5% clindamycin. Surgical sutures were prepared using this fiber, and the antibacterial rate against Escherichia coli was 35.0% and the antibacterial rate against Staphylococcus aureus was 35.0%.

[0090] Since antibacterial substances can affect the determination of fiber ash content and make it impossible to accurately measure the content of impurities, pure polyethylene fiber was prepared without adding clindamycin, following the method of Comparative Example 2. The resulting fiber had a breaking strength of 44 cN / dtex, an initial modulus of 1900 cN / dtex, and a fiber ash content of 0.1%.

[0091] Comparative Example 3

[0092] Ultra-high molecular weight polyethylene resin with a viscosity-average molecular weight of 5.8 million and a smooth surface free of slits, cracks, and pores was selected as the raw material. Following the method of Example 4 with other conditions unchanged, the resulting fiber had a breaking strength of 42 cN / dtex and an initial modulus of 1800 cN / dtex. Surgical sutures were prepared using this fiber, which contained 1.0% clindamycin. The surgical sutures prepared using this fiber showed an antibacterial rate of 30.0% against Escherichia coli and 30.0% against Staphylococcus aureus.

[0093] Following the method of Comparative Example 3, without adding clindamycin, pure polyethylene fibers were prepared. The resulting fibers had a breaking strength of 44 cN / dtex, an initial modulus of 1900 cN / dtex, and an ash content of 0.1%.

Claims

1. An antibacterial fiber comprising ultra-high molecular weight polyethylene fiber and an antibacterial substance, wherein the antibacterial substance is selected from at least one of cephalosporins, ofloxacin, vancomycin, ciprofloxacin, lincomycin, and fosfomycin, wherein the antibacterial fiber is prepared from ultra-high molecular weight polyethylene resin particles having slits or cracks with a surface width of 10-10000 nm through the following steps: a) preparing a spinning solution containing ultra-high molecular weight polyethylene resin and the antibacterial substance; b) extruding the spinning solution through a spinneret to obtain a spinning fluid; c) subjecting the spinning fluid to curing, drying, and hot stretching treatment, wherein step a) comprises: a1) Disperse ultra-high molecular weight polyethylene resin in an organic solvent, add antibacterial substances, and obtain a polyethylene suspension; a2) Pressurize the polyethylene suspension, controlling the pressure to be 0.1~1MPa during the pressurization process; a3) Heat to 30~60℃ and stir for 30~240min, then rapidly reduce the pressure to atmospheric pressure; the depth of the slits or cracks on the surface of the ultra-high molecular weight polyethylene resin particles is 0.01~50μm.

2. The antibacterial fiber according to claim 1, characterized in that: The antibacterial substance has a size of 200-800 mesh; and / or, The antibacterial substance is 2-10 wt% of ultra-high molecular weight polyethylene fiber.

3. The antibacterial fiber according to claim 2, characterized in that: The antibacterial substance has a size of 400-600 mesh; and / or, The antibacterial substance is 3-8 wt% of ultra-high molecular weight polyethylene fiber.

4. A method for preparing antibacterial fiber according to any one of claims 1 to 3, comprising the following steps: a) Prepare a spinning solution containing ultra-high molecular weight polyethylene resin and antibacterial substances; b) The spinning solution is extruded through a spinneret to obtain a spinning fluid; c) The antibacterial fiber is obtained by curing, drying and hot stretching the spinning fluid.

5. The method of claim 4, wherein Step a) includes: a1) Disperse ultra-high molecular weight polyethylene resin in an organic solvent, add antibacterial substances, and obtain a polyethylene suspension; a2) Pressurize the polyethylene suspension; a3) Heat and stir the mixture to rapidly reduce the pressure to atmospheric pressure.

6. The preparation method according to claim 5, characterized in that: The ultra-high molecular weight polyethylene resin has a viscosity-average molecular weight of 4 to 8 million; and / or, The antibacterial substance has a size of 200-800 mesh; and / or, The organic solvent is at least one selected from mineral oil, toluene, xylene, decahydronaphthalene, and tetrahydronaphthalene; the mineral oil is at least one selected from paraffin and kerosene; and / or, The content of ultra-high molecular weight polyethylene resin in the polyethylene suspension is 6-15%; and / or, The pressure is controlled at 0.1~1MPa during pressurization; and / or, Heat to 30~60℃ and stir for 30~240 minutes.

7. The method of claim 4, wherein When a volatile solvent is used in step a), the curing and drying in step c) include the following steps: c1) The spinning fluid is cooled and solidified into nascent filament by one or a combination of gas and liquid phases; c2) The solvent is removed from the nascent filament by at least one of the following methods: ring blowing, side blowing, and tunnel blowing, to obtain a solid filament.

8. The method of claim 4, wherein When a) uses a non-volatile solvent, the curing and drying in step c) includes the following steps: c1') The spinning fluid enters the extraction tank for extraction to obtain wet raw yarn, wherein the extraction tank contains an extractant to remove organic solvents from the spinning fluid; c2') The wet raw silk is processed by at least one of the following methods to remove the extractant, namely ring blowing, side blowing, and tunnel blowing, to obtain solid silk.

9. The method of claim 4, wherein In step c): The hot stretching process includes at least two stages of stretching.

10. The preparation method according to claim 9, characterized in that: The hot stretching treatment includes a first stretching at 140~145℃ and 3~6 times the original strength, and a second stretching at 144~148℃ and 1.1~2.0 times the original strength.

11. The antibacterial fiber according to any one of claims 1 to 3 or the antibacterial fiber obtained by the preparation method according to any one of claims 4 to 10 is used for surgical sutures or artificial joints.

Images