An antibacterial wear-resistant ultrahigh molecular weight polyethylene fiber and a preparation method thereof

Abstract

The application belongs to the technical field of polymer materials, and particularly relates to an antibacterial and wear-resistant ultrahigh molecular weight polyethylene fiber and a preparation method thereof. The application is spun through a coaxial spinning nozzle, so that the core layer and the skin layer are extruded at the same time, the advantages of the core layer and the skin layer materials are combined, the special structure of the nozzle is used, the two different melts are concentrically arranged in the extrusion process, a stable core-shell structure is formed, the obtained core-shell structure fiber is subjected to steam explosion treatment at a certain temperature and pressure, nanoscale grooves are formed on the surface, then the fiber is immersed in a sodium alginate-chitosan mixed solution, and a biological coating with a thickness of 200-300 nm is formed through the crosslinking action of calcium ions, the surface grooves and the biological coating are coordinated, the friction coefficient of the fiber surface can be effectively reduced, the abrasion during pet biting is reduced, and finally the antibacterial and wear-resistant ultrahigh molecular weight polyethylene fiber with excellent comprehensive performance is prepared.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and particularly relates to an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber and a preparation method thereof. BACKGROUND

[0002] Pet toys are important carriers for pets' daily activities, and common materials include rubber, PVC, ordinary polyethylene (PE), etc. However, the existing materials have the following problems: (1) insufficient antibacterial performance: when pets frequently bite the toys, saliva and food residues are easy to breed bacteria (such as Escherichia coli and Staphylococcus aureus), leading to excessive bacteria on the surface of the toys and causing infections in the oral cavity or digestive tract of pets. (2) poor wear resistance: ordinary PE or rubber materials are easy to wear and break under long-term biting, and the fragments may be mistakenly eaten by pets, which poses a safety hazard. (3) difficult to clean: the surface of traditional materials is rough and easy to hide dirt, and the antibacterial performance further decreases after cleaning.

[0003] Ultra-high molecular weight polyethylene (UHMWPE) fiber, also known as high-strength and high-modulus polyethylene fiber, has attracted extensive attention of researchers due to its ultra-high mechanical strength and modulus, extremely low density, high chemical corrosion resistance and impact strength, high wear resistance, and good biocompatibility, and is considered to have great development prospects in lightweight and high-strength composite materials.

[0004] In the prior art, ultra-high molecular weight polyethylene (UHMWPE) is often used in the industrial field due to its high wear resistance, but direct application in pet toys has limitations: lack of antibacterial functional design for pet needs; the surface friction coefficient is high, and dirt is easy to be adsorbed after long-term use; the existing antibacterial agents (such as silver ions) are easy to be lost due to wear or cleaning, and cannot achieve long-term antibacterial effect.

[0005] Therefore, it is urgent to develop a fiber material specially used for pet toys, which has long-term antibacterial and super wear-resistant properties. SUMMARY

[0006] The application aims to solve the existing problems, and provides an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber and a preparation method thereof.

[0007] The application is implemented by the following technical scheme:

[0008] A preparation method of an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber, comprising the following steps:

[0009] S1, the ultra-high molecular weight polyethylene, antibacterial master batch, nanocellulose whisker is mixed uniformly and then is added into a single screw extruder with a diameter of 30 mm to melt at a temperature range of 150-160℃ to obtain a core layer, and polylactic acid and 5% natural rubber powder by mass of polylactic acid are mixed and then are added into another single screw extruder with a diameter of 25 mm to melt at a temperature of 180-190℃ to obtain a skin layer, and then the core layer and the skin layer are extruded simultaneously through a coaxial spinning nozzle to form a core-shell structure fiber;

[0010] S2, the core-shell structure fiber obtained in step S1 is placed in a steam explosion device for steam explosion treatment, and then is immersed in a sodium alginate-chitosan mixed solution, filtered out after soaking for 1-2 h, and then is added into a calcium chloride solution for crosslinking reaction, and then is sequentially subjected to shaping, cleaning treatment after reaction for 20-30 min.

[0011] Further, the mass ratio of the ultra-high molecular weight polyethylene, the antibacterial master batch and the nanocellulose whisker in step S1 is 12-13:1.2-1.3:1.

[0012] Further, the preparation of the antibacterial master batch comprises the following steps:

[0013] 1) The chitosan powder is added into a ball mill, 0.6-1% stearic acid by mass of the chitosan powder is added, the rotation speed of the ball mill is set to 300-500 r / min, the grinding time is 2-4 h, and the temperature in the ball mill is controlled to be 40-50℃ during the grinding process, and after the grinding is completed, the refined chitosan powder is obtained by passing through a 200-300 mesh sieve;

[0014] 2) The tea polyphenol and the fatty acid are added into a three-necked flask containing toluene at a molar ratio of 1:1-1.4, 1-2% concentrated sulfuric acid by mass of the tea polyphenol is added after mixing, the reaction product is washed to neutral with saturated sodium carbonate after stirring and mixing, and then the reaction product is washed with deionized water for 3-4 times, and the modified tea polyphenol is obtained after drying;

[0015] 3) The refined chitosan powder obtained above is ultrasonically dispersed into 1% acetic acid aqueous solution, the modified tea polyphenol with the same mass as the refined chitosan powder is added after uniform dispersion, ultrasonic treatment is continued for 20-30 min, and then the antibacterial master batch is obtained by spray drying.

[0016] Further, the preparation of the nanocellulose whisker comprises the following steps:

[0017] (1) The bacterial cellulose membrane obtained by fermentation of wood vinegar bacteria is soaked in 0.1M NaOH solution at a ratio of 1g:50-60mL, stirred in a water bath at 60-70°C for 2-3h, then washed with deionized water until neutral, and vacuum filtered to obtain purified bacterial cellulose membrane;

[0018] (2) The purified cellulose membrane obtained in step (1) is cut into pieces and added to the reaction solution, which is oscillated at room temperature and 100-200r / min for 6-8h, then the same volume of ethanol is added, and the mixture is stirred for 20-30min and then centrifuged, and then washed with deionized water for 3-5 times to obtain oxidized bacterial cellulose slurry;

[0019] (3) The oxidized bacterial cellulose slurry obtained in step (2) is added to a high-pressure homogenizer and treated at a pressure of 30-40MPa for 2 cycles, then added to a cellulase solution for enzymatic hydrolysis, and after completion, ultrasonic treatment is performed to obtain short rod-shaped nanocellulose whiskers;

[0020] (4) The nanocellulose whiskers are ultrasonically dispersed in deionized water, and after uniform dispersion, 0.1M AgNO3 solution is added, shielded from light, and stirred at 100-300r / min for 8-10h, then 0.05wt% sodium citrate aqueous solution is added, mixed, then irradiated with ultraviolet light at a wavelength of 365nm, a power of 50W, and an irradiation distance of 10-20cm for 10-20min, then centrifuged, then washed with deionized water for 2-3 times, and then freeze-dried.

[0021] Further, the reaction solution preparation method in step (2) is: mixing 2,2,6,6-tetramethylpiperidine-1-oxyl solution, NaClO solution, and NaBr solution at a volume ratio of 1:1:1, then adjusting the pH to 10 with NaOH, wherein the concentration of 2,2,6,6-tetramethylpiperidine-1-oxyl solution is 0.05g / L, the concentration of NaClO solution is 7.45g / L, and the concentration of NaBr solution is 10.3g / L.

[0022] Further, the spinning speed in step S1 is 30-50m / min.

[0023] Further, the spinning in step S1 is performed simultaneously with pulse magnetic field treatment, and the pulse magnetic field strength is controlled to be 0.5T and the frequency is 10Hz.

[0024] Further, the pressure in the device is controlled to be 0.1-0.2MPa and the temperature is controlled to be 120-130°C during the steam explosion treatment in step S2, and the treatment time is 4-8min.

[0025] Further, the mass ratio of sodium alginate and chitosan in the sodium alginate-chitosan mixed solution in step S2 is 1:1-2;

[0026] The concentration of the calcium chloride solution is 5%.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] 1. The coaxial spinning nozzle is used for spinning to extrude the core layer and the skin layer at the same time to form the core-shell structure fiber, and the advantages of the core layer and the skin layer are combined, the core layer provides the properties of antibiosis, wear resistance and high strength, the skin layer endows the fiber with good surface properties, flexibility and biocompatibility, the special structure of the nozzle is used to arrange the two different melts concentrically in the extrusion process to form a stable core-shell structure, the pulse magnetic field treatment is performed at the same time of spinning, the dielectric effect of the nanocellulose whisker is used to induce the fiber to arrange along the fiber axis direction, and the wear resistance of the product is further improved. After the obtained core-shell structure fiber is treated by steam explosion at a certain temperature and pressure, nanoscale grooves are formed on the surface, then the fiber is immersed into a sodium alginate-chitosan mixed solution, and a biobased coating with a thickness of 200-300 nm is formed through the crosslinking effect of calcium ions, the surface grooves and the biobased coating cooperate to effectively reduce the friction coefficient of the fiber surface, thereby reducing the wear during the pet biting, the biobased coating can further improve the antibiosis of the product, and the biobased coating has biodegradability, and finally the antibacterial wear-resistant ultrahigh molecular weight polyethylene fiber with excellent comprehensive performance is prepared.

[0029] 2. The antibacterial master batch in the present application has the synergistic effect of contact sterilization (destroying the bacterial cell membrane) and the antioxidant and antibacterial effect of tea polyphenols, and the antibacterial rate of the Escherichia coli and Staphylococcus aureus commonly found in the oral cavity of pets is greater than 99.5%, and the antibacterial rate is still very high after multiple bites.

[0030] 3. The purified bacterial cellulose film is cut into pieces, and then subjected to oscillation reaction under specific conditions by using a special reaction solution, carboxyl groups are introduced on the surface of the oxidized bacterial cellulose through 2,2,6,6-tetramethylpiperidine-1-oxyl radical oxidation, the oxidized bacterial cellulose is preliminarily defibrillated into micron-level fiber bundles through high-pressure homogenization treatment, the single nanofiber is released through selective cutting of the amorphous region by cellulase, and the structure of the crystalline region is reserved, at this time, the nanofiber is stripped into short rod-shaped nanocellulose whiskers (CNC) by the action of ultrasonic waves, then the carboxyl groups on the surface of the CNC are used to chelate Ag + , and sodium citrate is reduced by ultraviolet light induction to induce Ag +The silver particles are reduced to nanoscale, the silver is uniformly anchored, the nanocellulose whiskers are antibacterial functionalized, the nanocellulose whiskers are used in preparation of the ultra-high molecular weight polyethylene fiber, the mechanical properties and wear resistance of the product are strengthened through directional arrangement, the distribution of the antibacterial components is optimized through high specific surface area and interface effect, the high specific surface area of the CNC can absorb chitosan and tea polyphenol to form an antibacterial component slow-release network, and efficient and long-acting bacteriostasis is realized. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The tensile strength results of the samples in each group are compared;

[0032] Figure 2 The antibacterial rate comparison results of the samples in each group on E. coli and S. aureus are compared;

[0033] Figure 3 The wear resistance comparison results of the samples in each group are compared. DETAILED DESCRIPTION

[0034] In order to further explain the present application, the following specific examples are combined.

[0035] Example 1

[0036] A preparation method of an antibacterial wear-resistant ultra-high molecular weight polyethylene fiber, comprising the following steps:

[0037] S1, the ultra-high molecular weight polyethylene, the antibacterial master batch and the nanocellulose whisker are uniformly mixed in a mass ratio of 12:1.2:1, and then added to a single screw extruder with a diameter of 30mm to melt at a temperature interval of 150℃ to obtain a core layer, and the polylactic acid and the natural rubber powder with a mass fraction of 5% of the polylactic acid are mixed, and then added to another single screw extruder with a screw diameter of 25mm to melt at a temperature of 180℃ to obtain a skin layer, and then spun through a coaxial spinning nozzle at a spinning speed of 30m / min to simultaneously extrude the core layer and the skin layer to form a core-shell structure fiber;

[0038] The pulse magnetic field treatment is carried out at the same time of spinning, the pulse magnetic field strength is controlled to be 0.5T, and the frequency is 10Hz;

[0039] The preparation of the antibacterial master batch comprises the following steps:

[0040] 1) The chitosan powder is added to a ball mill, 0.6% of the chitosan powder is added to stearic acid, the rotating speed of the ball mill is set to 300r / min, the grinding time is 2h, the temperature in the ball mill is controlled to be 40℃ during the grinding process, and after the grinding is completed, the refined chitosan powder is obtained by passing through a 200 mesh sieve;

[0041] 2) tea polyphenols and fatty acids are added to a three-necked flask containing toluene in a molar ratio of 1:1, 1% concentrated sulfuric acid of the mass of tea polyphenols is added after mixing, after stirring and mixing, reflux at 110°C for 4h, after the reaction is completed, cool to room temperature, then wash the reaction product to neutral with saturated sodium carbonate, then wash with deionized water for 3 times, dry to obtain modified tea polyphenols;

[0042] 3) the above obtained refined chitosan powder is ultrasonically dispersed in 1% acetic acid aqueous solution, after uniform dispersion, the refined chitosan powder is added in an equal mass of modified tea polyphenols, continue ultrasonic treatment for 20 min, then spray drying to obtain antibacterial master batch;

[0043] The preparation of the nanocellulose whisker comprises the following steps:

[0044] (1) the bacterial cellulose film obtained by fermentation of acetic acid bacteria is soaked in 0.1M NaOH solution at a ratio of 1g:50mL, stirred in water bath at 60°C for 2h, then washed with deionized water to neutral, vacuum filtration to obtain purified bacterial cellulose film;

[0045] (2) the purified cellulose film obtained in step (1) is cut into pieces and added to the reaction solution, oscillated at room temperature and 100r / min for 6h, then the same volume of ethanol is added to the reaction solution, continue to stir for 20 min, then centrifuge, then wash with deionized water for 3 times to obtain oxidized bacterial cellulose slurry;

[0046] The preparation method of the reaction solution is as follows: 2,2,6,6-tetramethylpiperidine-1-oxyl solution, NaClO solution and NaBr solution are mixed in a volume ratio of 1:1:1, then the pH is adjusted to 10 with NaOH, wherein the concentration of 2,2,6,6-tetramethylpiperidine-1-oxyl solution is 0.05g / L, the concentration of NaClO solution is 7.45g / L, and the concentration of NaBr solution is 10.3g / L;

[0047] (3) the oxidized bacterial cellulose slurry obtained in step (2) is added to a high-pressure homogenizer and treated with a pressure of 30MPa for 2 cycles, then it is added to a cellulase solution for enzymatic hydrolysis, after completion, ultrasonic treatment is performed to obtain short rod-shaped nanocellulose whiskers;

[0048] (4) the nanocellulose whiskers are ultrasonically dispersed in deionized water, after uniform dispersion, 0.1M AgNO3 solution is added, shielded from light, stirred at 100r / min for 8h, then 0.05wt% sodium citrate aqueous solution is added, mixed, then ultraviolet irradiation is performed for 10 min at a wavelength of 365nm, power of 50W and irradiation distance of 10cm, then centrifuge, then washed with deionized water for 2 times, then freeze-dried;

[0049] S2, the core-shell structure fiber obtained in step S1 is placed in a steam explosion device for steam explosion treatment, the pressure in the device is controlled to be 0.1 MPa, the temperature is 120 DEG C, and the treatment time is 4 min, then the core-shell structure fiber is immersed in a sodium alginate-chitosan mixed solution, the mass ratio of sodium alginate to chitosan in the sodium alginate-chitosan mixed solution is 1:1, the core-shell structure fiber is filtered out after soaking for 1 h, and then is added to a calcium chloride solution (the concentration is 5%) for cross-linking reaction, and after reaction for 20 min, the core-shell structure fiber is subjected to shaping and cleaning treatment in sequence.

[0050] Example 2

[0051] A preparation method of an antibacterial wear-resistant ultrahigh molecular weight polyethylene fiber, comprising the following steps:

[0052] S1, the ultrahigh molecular weight polyethylene, the antibacterial master batch and the nanocellulose whisker are uniformly mixed according to a mass ratio of 12.5:1.25:1, and then are added to a single screw extruder with a diameter of 30 mm to melt at a temperature interval of 155 DEG C to obtain a core layer; meanwhile, the polylactic acid and the natural rubber powder with a mass of 5% of the polylactic acid are mixed, and then are added to another single screw extruder with a diameter of 25 mm to melt at a temperature of 185 DEG C to obtain a skin layer; then the core layer and the skin layer are extruded simultaneously through a coaxial spinning nozzle at a spinning speed of 40 m / min to form a core-shell structure fiber;

[0053] The pulse magnetic field treatment is performed simultaneously with the spinning, and the pulse magnetic field strength is controlled to be 0.5 T and the frequency is 10 Hz;

[0054] The preparation of the antibacterial master batch comprises the following steps:

[0055] 1) the chitosan powder is added to a ball mill, 0.8% of the chitosan powder is added as stearic acid, the rotating speed of the ball mill is set to be 400 r / min, the grinding time is 3 h, and the temperature in the ball mill is controlled to be 45 DEG C during the grinding process; after the grinding is completed, the refined chitosan powder is obtained by passing through a 250-mesh sieve;

[0056] 2) the tea polyphenol and the fatty acid are added to a three-necked flask containing toluene according to a molar ratio of 1:1.2, 1.5% of the tea polyphenol is added as concentrated sulfuric acid, the mixture is stirred and mixed, then is refluxed at a temperature of 115 DEG C for 4.5 h, after the reaction is completed, the reaction product is cooled to room temperature, then is washed to be neutral by using saturated sodium carbonate, and then is washed with deionized water for 3 times, and the modified tea polyphenol is obtained by drying;

[0057] 3) the refined chitosan powder is ultrasonically dispersed in 1% of an acetic acid aqueous solution, after being uniformly dispersed, the refined chitosan powder is added with the same mass of the modified tea polyphenol, and then is continuously ultrasonically treated for 25 min, and the antibacterial master batch is obtained by spray drying;

[0058] The preparation of the nanocellulose whisker comprises the following steps:

[0059] (1) The bacterial cellulose film obtained by fermentation of wood acetic acid bacteria is soaked in a 0.1M NaOH solution at a ratio of 1g:55mL, stirred in a water bath at 65℃ for 2.5h, then washed with deionized water until neutral, and vacuum filtered to obtain a purified bacterial cellulose film;

[0060] (2) The purified bacterial cellulose film obtained in step (1) is cut into pieces and added to a reaction solution, which is oscillated at room temperature and 150r / min for 7h, then the same volume of ethanol is added, and the stirring is continued for 25min before centrifugation, and then the oxidized bacterial cellulose slurry is obtained by washing with deionized water for 4 times;

[0061] The preparation method of the reaction solution is as follows: 2,2,6,6-tetramethylpiperidine-1-oxyl solution, NaClO solution and NaBr solution are mixed in a volume ratio of 1:1:1, and then the pH is adjusted to 10 with NaOH, wherein the concentration of 2,2,6,6-tetramethylpiperidine-1-oxyl solution is 0.05g / L, the concentration of NaClO solution is 7.45g / L, and the concentration of NaBr solution is 10.3g / L;

[0062] (3) The oxidized bacterial cellulose slurry obtained in step (2) is added to a high-pressure homogenizer and treated with a pressure cycle of 35MPa for 2 times, then it is added to a cellulase solution for enzymatic hydrolysis, and after completion, ultrasonic treatment is performed to obtain short rod-shaped nanocellulose whiskers;

[0063] (4) The nanocellulose whiskers are ultrasonically dispersed in deionized water, and after uniform dispersion, 0.1M AgNO3 solution is added, and the mixture is stirred in the dark at 200r / min for 9h, then 0.05wt% sodium citrate aqueous solution is added, mixed, and then ultraviolet irradiation is performed at a wavelength of 365nm, a power of 50W, and an irradiation distance of 15cm for 15min, followed by centrifugation, then washed with deionized water for 2 times, and then freeze-dried to obtain the product;

[0064] S2, the core-shell structure fiber obtained in step S1 is placed in a steam explosion device for steam explosion treatment, the pressure in the device is controlled at 0.15MPa, the temperature is 125℃, and the treatment time is 6min, then the fiber is immersed in a sodium alginate-chitosan mixed solution, the mass ratio of sodium alginate to chitosan in the mixed solution is 1:1.5, the fiber is soaked for 1.5h and then filtered out, and then added to a calcium chloride solution (concentration of 5%) for crosslinking reaction, and then sequentially subjected to shaping, cleaning treatment.

[0065] Example 3

[0066] A preparation method of an antibacterial wear-resistant ultrahigh molecular weight polyethylene fiber, comprising the following steps:

[0067] S1, the ultrahigh molecular weight polyethylene, the antibacterial master batch, the nanocellulose whisker are mixed uniformly according to 13:1.3:1 mass ratio, then are added to a single screw extruder with a diameter of 30mm, are melted in a temperature interval of 160 DEG C to obtain a core layer, meanwhile, polylactic acid and 5% natural rubber powder of the mass of polylactic acid are mixed, then are added to another single screw extruder with a screw diameter of 25mm, are melted at a temperature of 190 DEG C to obtain a skin layer, then are spun through a coaxial spinning nozzle, the spinning speed is 50m / min, so that the core layer and the skin layer are extruded simultaneously to form a core-shell structure fiber;

[0068] The pulse magnetic field treatment is carried out simultaneously with spinning, the pulse magnetic field strength is controlled to be 0.5T, and the frequency is 10Hz;

[0069] The preparation of the antibacterial master batch comprises the following steps:

[0070] 1) the chitosan powder is added to a ball mill, 1% stearic acid of the mass of the chitosan powder is added, the rotating speed of the ball mill is set to be 500r / min, the grinding time is 4h, the temperature in the ball mill is controlled to be 50 DEG C during the grinding process, after the grinding is completed, the refined chitosan powder is obtained by passing through a 300 mesh sieve;

[0071] 2) tea polyphenol and fatty acid are added to a three-necked flask containing toluene according to a molar ratio of 1:1.4, 2% concentrated sulfuric acid of the mass of the tea polyphenol is added after mixing, after stirring and mixing, the reaction product is washed to be neutral by using saturated sodium carbonate, and then washed with deionized water for 4 times, and the modified tea polyphenol is obtained after drying;

[0072] 3) the refined chitosan powder is ultrasonically dispersed into 1% acetic acid aqueous solution, after uniform dispersion, the modified tea polyphenol with the same mass of the refined chitosan powder is added, after 30min of ultrasonic treatment, the antibacterial master batch is obtained by spray drying;

[0073] The preparation of the nanocellulose whisker comprises the following steps:

[0074] (1) the bacterial cellulose membrane obtained by fermentation of acetic acid bacteria is soaked in 0.1M NaOH solution according to the ratio of 1g:60mL, after stirring in a water bath at 70 DEG C for 3h, the purified bacterial cellulose membrane is obtained by washing to be neutral with deionized water and vacuum filtration;

[0075] (2) The purified cellulose film obtained in step (1) is cut into pieces and added to a reaction solution, which is oscillated at room temperature and 200 r / min for 8 h, then the reaction solution is added with an equal volume of ethanol, and after stirring for another 30 min, centrifugation is performed, followed by washing with deionized water for 5 times to obtain an oxidized bacterial cellulose slurry;

[0076] The reaction solution is prepared by mixing 2,2,6,6-tetramethylpiperidine-1-oxyl solution, NaClO solution and NaBr solution in a volume ratio of 1:1:1, and then adjusting the pH to 10 with NaOH, wherein the concentration of the 2,2,6,6-tetramethylpiperidine-1-oxyl solution is 0.05 g / L, the concentration of the NaClO solution is 7.45 g / L, and the concentration of the NaBr solution is 10.3 g / L;

[0077] (3) The oxidized bacterial cellulose slurry obtained in step (2) is added to a high-pressure homogenizer and treated with a pressure cycle of 40 MPa for 2 times, and then added to a cellulase solution for enzymatic hydrolysis, and after completion, ultrasonic treatment is performed to obtain short rod-shaped nanocellulose whiskers;

[0078] (4) The nanocellulose whiskers are ultrasonically dispersed in deionized water, and after uniform dispersion, 0.1 M AgNO3 solution is added, and the mixture is stirred in the dark at 300 r / min for 10 h, then 0.05 wt% sodium citrate aqueous solution is added, and after mixing, ultraviolet irradiation is performed at a wavelength of 365 nm, a power of 50 W, and an irradiation distance of 20 cm for 20 min, followed by centrifugation, then washing with deionized water for 3 times, and finally freeze-drying to obtain the product.

[0079] S2, the core-shell structure fiber obtained in step S1 is placed in a steam explosion device for steam explosion treatment, the pressure in the device is controlled to be 0.2 MPa, the temperature is 130℃, and the treatment time is 8 min, then the fiber is immersed in a sodium alginate-chitosan mixed solution, the mass ratio of sodium alginate to chitosan in the mixed solution is 1:2, the fiber is soaked for 2 h and then filtered out, and then added to a calcium chloride solution (concentration of 5%) for crosslinking reaction, and after reaction for 30 min, the fiber is sequentially subjected to shaping and cleaning treatment.

[0080] Comparative Example 1

[0081] The preparation of the antibacterial master batch comprises the following steps:

[0082] 1) Chitosan powder is added to a ball mill, 0.8% of the chitosan powder is stearic acid, the rotation speed of the ball mill is set to 400 r / min, and the grinding time is 3 h, and the temperature in the ball mill is controlled to be 45℃ during the grinding process, and after the grinding is completed, the refined chitosan powder is obtained by passing through a 250 mesh sieve;

[0083] 2) Ultrasonic dispersion of the refined chitosan powder obtained above into a 1% acetic acid aqueous solution. After uniform dispersion, tea polyphenols in an amount equal to the mass of the refined chitosan powder were added. Ultrasonic treatment was continued for 25 minutes, and then spray drying was performed to obtain antibacterial masterbatch I.

[0084] This comparative example 1 is based on Example 2, except that the antibacterial masterbatch is replaced with antibacterial masterbatch I, and the rest of the technical solutions are the same as those of Example 2.

[0085] Comparative Example 2

[0086] Comparative Example 2 is based on Example 2, and the spinning in step S1 is omitted while performing pulse magnetic field treatment. The rest of the technical solutions are the same as those in Example 2.

[0087] Comparative Example 3

[0088] Comparative Example 3 is based on Example 2, omitting the nanocellulose whiskers, and the rest of the technical solutions are the same as those in Example 2.

[0089] Comparative Example 4

[0090] Comparative Example 4 is based on Comparative Example 2, omitting the steam explosion treatment in step S2, and the remaining technical solutions are the same as those in Example 2.

[0091] Experimental testing

[0092] 1. Mechanical properties test

[0093] The tensile strength of each group of fiber samples was tested using a universal electronic tensile testing machine. Figure 1 shown.

[0094] Depend on Figure 1 It can be seen that the tensile strength of the ultra-high molecular weight polyethylene fibers prepared by the methods of Examples 1 to 3 is significantly better than that of the comparative example, that is, the present invention retains the mechanical strength of the ultra-high molecular weight polyethylene fibers well while improving the antibacterial and wear resistance.

[0095] 2. Antibacterial performance test

[0096] The antibacterial properties of the fiber were studied using the colony counting method.

[0097] The cultured Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were diluted to 10 7 CFU / mL was used as the experimental bacterial solution. The antibacterial activity of each group of fiber samples was tested and analyzed according to the GB / T20944.3-2008 oscillation method, and the antibacterial rate was calculated. The incubation time was 24 hours, and three parallel plates were made for each group.

[0098] The test comparison results are as follows Figure 2 shown.

[0099] Depend on Figure 2 It can be seen that after 24 hours of action with bacteria, the antibacterial rates of Examples 1 to 3 against E. coli and S. aureus are 99.8% to 99.99% and 99.91% to 99.97%, respectively, which have strong antibacterial properties. The antibacterial effects are significantly better than those of Comparative Examples 1 to 4. It can be seen that the preparation method of the present invention can significantly improve the antibacterial properties of ultra-high molecular weight polyethylene fibers.

[0100] 3. Wear resistance test

[0101] The wear resistance of ultra-high molecular weight polyethylene (UHMWPE) filaments was determined with reference to the method in FZ / T 50025-2014 “Test method for abrasion resistance of ultra-high molecular weight polyethylene filaments”.

[0102] The test results are as follows Figure 3 shown.

[0103] Depend on Figure 3 It can be seen that the maximum friction times of the ultra-high molecular weight polyethylene fibers prepared by the methods of Examples 1 to 3 are as high as 3150 to 3250, which are significantly better than those of the comparative examples, indicating that the improvements in the raw materials and methods of the present application can greatly improve the wear resistance of the products.

[0104] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber, characterized in that: The steps include: S1. After mixing ultra-high molecular weight polyethylene, antibacterial masterbatch, and nanocellulose whiskers, the mixture was added to a single-screw extruder with a diameter of 30 mm, and the mixture was melted in a temperature range of 150-160° C. to obtain a core layer. At the same time, polylactic acid was mixed with natural rubber powder containing 5% by weight of polylactic acid, and the mixture was added to another single-screw extruder with a screw diameter of 25 mm. The mixture was melted at a temperature of 180-190° C. to obtain a skin layer. The mixture was then spun through a coaxial spinning nozzle to extrude the core layer and the skin layer simultaneously to form a core-shell structure fiber. During the spinning, a pulsed magnetic field treatment was performed, and the pulsed magnetic field intensity was controlled to be 0.5 T and the frequency to be 10 Hz. The preparation of the antibacterial masterbatch comprises the following steps: 1) Add chitosan powder into a ball mill, add 0.6-1% stearic acid based on the mass of the chitosan powder, set the ball mill speed to 300-500 r / min, grind for 2-4 hours, and control the temperature in the ball mill to 40-50°C during the grinding process. After grinding, pass through a 200-300 mesh sieve to obtain fine chitosan powder; 2) Tea polyphenols and fatty acids were added to a three-necked flask containing toluene at a molar ratio of 1:1-1.4, and concentrated sulfuric acid (1-2% by weight of the tea polyphenols) was added after mixing. The mixture was stirred and refluxed at 110-120°C for 4-5 hours. After the reaction was completed, the mixture was cooled to room temperature, and the reaction product was washed with saturated sodium carbonate until neutral, washed with deionized water 3-4 times, and dried to obtain the modified tea polyphenols. 3) Ultrasonic dispersion of the refined chitosan powder obtained above into a 1% acetic acid aqueous solution. After uniform dispersion, modified tea polyphenols of equal mass to the refined chitosan powder are added, and ultrasonic treatment is continued for 20-30 minutes, followed by spray drying to obtain the antibacterial masterbatch. S2. The core-shell structure fiber obtained in step S1 is placed in a steam explosion device for steam explosion treatment, and then immersed in a sodium alginate-chitosan mixture for 1-2 hours, filtered out, and then added to a calcium chloride solution for cross-linking reaction. After reacting for 20-30 minutes, the fiber is shaped and washed in sequence.

2. The method for preparing an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that: The mass ratio of the ultra-high molecular weight polyethylene, antibacterial masterbatch, and nanocellulose whiskers described in step S1 is 12-13:1.2-1.3:

1.

3. The method for preparing an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber according to claim 2, characterized in that: The preparation of the nanocellulose whiskers comprises the following steps: (1) The bacterial cellulose membrane obtained by fermentation of Acetobacter xylinum was immersed in a 0.1 M NaOH solution at a ratio of 1 g: 50-60 mL, stirred in a water bath at 60-70 °C for 2-3 h, washed with deionized water until neutral, and vacuum filtered to obtain the purified bacterial cellulose membrane; (2) Cut the purified cellulose membrane obtained in step (1) into pieces, add the pieces to the reaction solution, shake the reaction at room temperature and 100-200 r / min for 6-8 hours, add the same volume of ethanol as the reaction solution, continue stirring for 20-30 minutes, centrifuge, and then wash with deionized water 3-5 times to obtain oxidized bacterial cellulose slurry; (3) adding the oxidized bacterial cellulose slurry obtained in step (2) into a high-pressure homogenizer, cyclically treating it twice at a pressure of 30-40 MPa, then adding it into a cellulase solution for enzymatic hydrolysis, and then ultrasonically treating it to obtain short rod-shaped nanocellulose whiskers; (4) Ultrasonic dispersion of nanocellulose whiskers in deionized water, adding 0.1M AgNO3 solution after uniform dispersion, shielding from light, stirring at 100-300 r / min for 8-10 h, adding 0.05wt% sodium citrate aqueous solution, mixing, and irradiating with ultraviolet light at a wavelength of 365nm, a power of 50W, and an irradiation distance of 10-20cm for 10-20 min, then centrifuging, washing with deionized water 2-3 times, and freeze-drying.

4. The method for preparing an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber according to claim 3, characterized in that: The method for preparing the reaction solution described in step (2) is: mixing 2,2,6,6-tetramethylpiperidine-1-oxyl free radical solution, NaClO solution, and NaBr solution in a volume ratio of 1:1:1, and then adjusting the pH to 10 with NaOH, wherein the concentration of 2,2,6,6-tetramethylpiperidine-1-oxyl free radical solution is 0.05 g / L, the concentration of NaClO solution is 7.45 g / L, and the concentration of NaBr solution is 10.3 g / L.

5. The method for preparing an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that: The spinning speed during the spinning in step S1 is 30-50 m / min.

6. The method for preparing an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that: During the steam explosion treatment in step S2, the pressure in the equipment is controlled to be 0.1-0.2 MPa, the temperature is controlled to be 120-130° C., and the treatment time is controlled to be 4-8 minutes.

7. The method for preparing an antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber according to claim 1, characterized in that: The mass ratio of sodium alginate to chitosan in the sodium alginate-chitosan mixture described in step S2 is 1:1-2; The concentration of calcium chloride solution is 5%.

8. The antibacterial and wear-resistant ultra-high molecular weight polyethylene fiber prepared by the method according to any one of claims 1 to 7.

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