A method for preparing a high-strength ultra-high molecular weight polyethylene fiber composite

Abstract

The application relates to the field of high polymer materials and discloses a preparation method of a high-strength ultrahigh molecular weight polyethylene fiber composite material, which comprises the following steps: (1) pretreatment of ultrahigh molecular weight polyethylene fiber; (2) phenol amine co-deposition modification; (3) metal ion modification; (4) three-way weaving of the ultrahigh molecular weight polyethylene fiber; and (5) preparation of the composite material. The ultrahigh molecular weight polyethylene fiber is modified by using catechol and 1,6-hexanediamine for coating, and metal ions are combined with the fiber through coordination bond action, the composite material prepared by the method has good interfacial bonding strength between the ultrahigh molecular weight polyethylene fiber and the matrix material, and the composite material has excellent mechanical properties. In addition, the composite material also has excellent antibacterial property.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer materials, and particularly relates to a preparation method of high-strength ultra-high molecular weight polyethylene fiber composite material. BACKGROUND

[0002] Ultra-high molecular weight polyethylene fiber is one of the three high-performance fibers, which has a series of excellent properties such as low density, high strength, high modulus, corrosion resistance and impact resistance. The application field of ultra-high molecular weight polyethylene fiber is very wide, which can be used in stab-resistant clothing, bulletproof helmet, bulletproof armor, ship cable, aerospace devices and the like. However, the ultra-high molecular weight polyethylene fiber is a non-polar material composed of methylene, which has the characteristics of smooth surface, extremely low surface energy, chemical inertness and poor composite property with matrix materials such as epoxy resin, which seriously limits the application of ultra-high molecular weight polyethylene fiber.

[0003] However, with the steady development of social economy and the improvement of people's living standards, the health consciousness and life safety consciousness of the people are constantly enhanced. Due to its excellent performance, the demand for ultra-high molecular weight polyethylene fiber in the market is rapidly increasing, and the application field is gradually expanding. In the field of protective products and the like, the antibacterial and bonding properties of the fiber are required to be high, and in the past modification of ultra-high molecular weight polyethylene fiber, the modification with both antibacterial and bonding properties is less involved. Chinese patent CN109385689 discloses a spinning method of blending ultra-high molecular weight polyethylene, which has a strength of 14-28 cN / dtex, but does not involve the antibacterial effect of the fiber; Chinese patent CN112626634 discloses an injection molding grade antibacterial ultra-high molecular weight polyethylene fiber and a preparation method thereof. The viscosity average molecular weight of the ultra-high molecular weight polyethylene used in this patent is as high as 3.5-6 million, and the material is difficult to disperse uniformly, so it is necessary to add other lubricating substances to reduce the van der Waals force between the molecular chains and improve the fluidity of the material, which increases the production cost and the process is complex; Chinese patent CN115262015 discloses a preparation method of a durable and efficient antibacterial fiber, which pre-mixes amphiphilic antibacterial polymer, UHMWPE resin, antioxidant and plasticizer, and then kneads at high speed for 30-60 min, granulates by double-screw extrusion, and then melts and extrudes from the spinneret hole by single-screw extruder, and obtains a durable and efficient antibacterial fiber by melt spinning-high draw process, but the mechanical strength is reduced to a certain extent and the process flow is complex, and the multi-effect of high strength, high viscosity and antibacterial is not realized.

[0004] Therefore, it is crucial for the ultra-high molecular weight polyethylene fiber itself and its application field to how to combine the excellent mechanical, interfacial and antibacterial properties of the ultra-high molecular weight polyethylene fiber, and to solve the problems of complex production process flow and high production cost in the preparation process of the ultra-high molecular weight polyethylene fiber. SUMMARY

[0005] To solve the above technical problems, the present application provides a method for preparing a high-strength ultra-high molecular weight polyethylene fiber composite material. The composite material prepared by the method has excellent bonding strength between the ultra-high molecular weight polyethylene fiber and the matrix material, so that the composite material has excellent mechanical properties. In addition, the composite material also has excellent antibacterial properties.

[0006] The specific technical scheme of the present application is as follows: a method for preparing a high-strength ultra-high molecular weight polyethylene fiber composite material, comprising the following steps:

[0007] (1) cleaning the surface of the ultra-high molecular weight polyethylene fiber to obtain ultra-high molecular weight polyethylene fiber with a surface free of impurities.

[0008] (2) dissolving trimethylol aminomethane hydrochloride in water, adjusting the pH to be alkaline after sufficient stirring, and adding o-diphenol and 1,6-hexanediamine and stirring until dissolved; placing the ultra-high molecular weight polyethylene fiber in the obtained solution and oscillating the reaction, taking out and washing with water and drying to obtain phenol-amine co-deposited modified ultra-high molecular weight polyethylene fiber.

[0009] (3) placing the phenol-amine co-deposited modified ultra-high molecular weight polyethylene fiber in a solution containing antibacterial metal ions and stirring at room temperature, taking out and washing with water and drying to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0010] (4) weaving the antibacterial ultra-high molecular weight polyethylene fiber into a three-dimensional woven structure ultra-high molecular weight polyethylene fiber bundle.

[0011] (5) placing the three-dimensional woven structure ultra-high molecular weight polyethylene fiber bundle horizontally in a mold and straightening it, injecting un-solidified matrix material into the mold, and obtaining a high-strength ultra-high molecular weight polyethylene fiber composite material after solidification.

[0012] The present application modifies the surface of the ultra-high molecular weight polyethylene fiber by Michael addition or Schiff base reaction of o-diphenol and 1,6-hexanediamine, and then modifies the ultra-high molecular weight polyethylene fiber by coordination bond of amino group and antibacterial metal ions. The ultra-high molecular weight polyethylene fiber is woven into a single yarn by three-dimensional weaving design, and embedded into the matrix to obtain a composite material.

[0013] Among them, (1) the Michael addition or Schiff base reaction of catechol and 1,6-hexanediamine can form a coating on the surface of ultra-high molecular weight polyethylene fiber, bringing active groups such as amino groups into the fiber surface, effectively overcoming the chemical inertness of ultra-high molecular weight polyethylene fiber, while improving the mechanical strength of the fiber surface and enhancing the interfacial shear strength between the fiber and the matrix material. The reason for choosing 1,6-hexanediamine and catechol is that catechol and 1,6-hexanediamine can undergo polymerization reaction, and both can form a phenol-amine coating with strong adhesion on the material. The reason for choosing 1,6-hexanediamine is that the amino density in the molecule is suitable, which is beneficial to improving the interfacial adhesion performance between the fiber and the matrix material (especially epoxy resin). If the amino density is too high, the phenol-amine coating will be too crosslinked and the coating will be too rigid; conversely, if the amino density is low, the coating will be unstable. The polymer modified with catechol groups can form multiple hydrogen bonds, π bonds, complex bonds and other strong interactions with metals, thus exhibiting excellent adhesion performance. Because the phenolic hydroxyl group can only undergo oxidative self-polymerization with 1,6-hexanediamine when it is in the ortho position of the benzene ring to form a coating with strong adhesion, and loses adhesion when the hydroxyl group is in the meta or para position of the benzene ring, compounds containing catechol groups are selected to modify the fibers. Compared with other compounds containing catechol groups, catechol is the smallest structural unit and has excellent chemical stability. In addition, the low market price is a significant advantage of catechol as a modifying raw material. (2) Through the coordination bond between antibacterial metal ions and amino groups, the fiber and antibacterial metal ions are stably combined, further improving the roughness of the fiber surface, while giving the high molecular weight polyethylene fiber excellent antibacterial properties, thus broadening the application prospects of ultra-high molecular weight polyethylene fiber. (3) Compared with the parallel fiber arrangement structure, the three-way braiding design can greatly improve the mechanical strength of the single yarn. The regular concave and convex surface of the single yarn formed by the macroscopic braiding structure can effectively prevent the fiber from slipping with the epoxy resin matrix. The three-way braiding design and the rough surface work together to significantly improve the mechanical strength of epoxy resin-based composite materials.

[0014] Preferably, step (1) specifically includes: placing ultra-high molecular weight polyethylene fiber into a mixed solution of ethanol and acetone and sonicating it, then taking it out, washing it with water, and drying it to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface; the volume ratio of ethanol to acetone is 1:(0.5-1), the sonication time is 60-120 min, and the drying temperature is 40-70℃.

[0015] During routine storage, ultra-high molecular weight polyethylene (UHMWPE) fibers may accumulate impurities, affecting subsequent chemical modification processes. To effectively remove solid particles and other impurities from the surface of UHMWPE fibers, the fibers are immersed in a mixed solution of ethanol and acetone in a specific volume ratio and then subjected to ultrasonic treatment.

[0016] Preferably, in step (2), the adjusted pH is 8-9.

[0017] Catechol can be converted to a quinone structure under alkaline conditions, undergoing Michael addition or Schiff base reaction with the amino group of 1,6-hexanediamine to form a network structure. In this process, pH has a significant impact on the chemical reaction. If the pH is too low, the hydroxyl group of catechol cannot be converted to a carbonyl group, thus preventing the reaction with 1,6-hexanediamine. If the pH is too high, it may cause some damage to ultra-high molecular weight polyethylene fibers.

[0018] Preferably, in step (2), the ratio of the amount of tris(hydroxymethyl)aminomethane hydrochloride, water, catechol and 1,6-hexanediamine is 0.4-0.8g:100mL:0.15-0.25g:0.2-0.4g.

[0019] The Michael addition or Schiff base reaction between catechol and 1,6-hexanediamine plays a decisive role in coating formation, thus affecting the mechanical strength of ultra-high molecular weight polyethylene fiber composites. If the mass of 1,6-hexanediamine is too low, the resulting coating will be too thin, and the roughness may decrease. Simultaneously, a low content of active groups such as amino groups in the coating is detrimental to the stable bonding between the modified ultra-high molecular weight polyethylene fiber and the matrix material. Appropriately increasing the relative content of 1,6-hexanediamine can result in a coating containing more primary amines, which is beneficial for the reaction between amino groups and matrix materials such as epoxy resin, increasing the reaction sites between the coating and the matrix material, enhancing the interfacial adhesion of the fiber, and improving the mechanical strength of the composite material. However, if the relative content of 1,6-hexanediamine is too high, it will lead to a decrease in the utilization rate of 1,6-hexanediamine. Simultaneously, the excess diamine acts as a capping agent, reducing the degree of crosslinking, weakening the interaction force between the coating and the fiber, and consequently reducing the interfacial strength, making the coating prone to detachment from the fiber surface.

[0020] Preferably, in step (2), the reaction time is 14-20 h and the drying temperature is 40-70 °C.

[0021] Preferably, in step (2), the bath ratio of the ultra-high molecular weight polyethylene fiber to the solution is 1g:(2300-2700)mL.

[0022] Reaction time affects the coating thickness and the number of active groups. If the reaction time is too short, the coating formed by catechol and 1,6-hexanediamine is too thin, resulting in too few active groups introduced onto the fiber surface. This leads to poor interfacial bonding strength between ultra-high molecular weight polyethylene fibers and matrix materials such as epoxy resin, resulting in lower mechanical strength of the composite material. Studies have shown that extending the reaction time does not affect the mechanical properties of ultra-high molecular weight polyethylene fiber composites; therefore, excessively long reaction times are meaningless for improving the performance of the composite material.

[0023] Preferably, in step (3), the solution containing antibacterial metal ions is AgNO3 solution, Cu(NO3)2 solution, or C4H solution. 10 OZn solution; the concentration of antibacterial metal ions in the solution is 0.05-0.09 mol / L; the stirring time is 1-4 h, and the drying temperature is 40-70℃.

[0024] Preferably, in step (3), the bath ratio of the ultra-high molecular weight polyethylene fiber to the solution containing antibacterial metal ions is 1 g: (2300-2700) mL.

[0025] Antibacterial metal ions bind to amino groups through coordination bonds, thereby enabling ultra-high molecular weight polyethylene fibers to achieve antibacterial properties. The stirring time in step (3) affects the modification process of the fibers by the antibacterial metal ions. If the stirring time is too short, not only will the amount of antibacterial metal ions bound to the fibers be insufficient, potentially leading to poor antibacterial performance, but the fiber roughness will also decrease, reducing the physical bonding force between the fibers and the epoxy resin, resulting in poor interfacial shear strength and the mechanical strength of the composite material. If the stirring time is too long, there will be too many antibacterial metal elements on the fiber surface, leading to increased preparation costs and a certain degree of biotoxicity.

[0026] As a preferred option, step (4) specifically includes: using a 32-spindle vertical braiding machine to add axial yarn fibers along the braiding curl direction, and obtaining a three-way braided structure of ultra-high molecular weight polyethylene fiber bundles under a certain gear ratio and rotation speed.

[0027] Preferably, in step (4), the number of yarn fibers is 20-50; the gear ratio is (driving gear: driven gear) = (30-44): 88, and the rotation speed is 40-80 rpm.

[0028] The number of axial yarns is directly proportional to the radius of the single yarn; the more axial yarns added, the thicker the woven single yarn. Furthermore, the addition of axial yarns increases the bending and entanglement between fibers, improving radial compression resistance and thus enhancing the mechanical properties of the single yarn. If the number of axial yarns is too small, the woven single yarn will have poor mechanical properties, which is detrimental to improving the mechanical strength of the composite material.

[0029] Preferably, in step (5), the uncured matrix material is a mixture of epoxy resin and curing agent, or cement.

[0030] Preferably, in step (5), the mass ratio of the epoxy resin to the curing agent is 3:(1-1.5).

[0031] Preferably, in step (5), the ratio of the amount of the ultra-high molecular weight polyethylene fiber bundle to the amount of the uncured matrix material is (1-5) bundles: 10 mL.

[0032] Compared with existing technologies, the beneficial effects of this invention are as follows: First, ultra-high molecular weight polyethylene (UHMWPE) fibers are cleaned. Then, the fibers are modified through Michael addition or Schiff base reaction of catechol and 1,6-hexanediamine, forming a cross-linked network coating on the fiber surface. Finally, the antibacterial metal ions are stably composited with the fibers using the coordination bond between antibacterial metal ions and amino groups, resulting in antibacterial UHMWPE fibers with high bonding strength. The phenol-amine co-deposition treatment introduces active groups such as amino groups onto the surface of the UHMWPE fibers, which facilitates the formation of chemical bonds or intermolecular forces between the fibers and the matrix material, thereby enhancing the interaction between the fibers and the matrix material. The formation of the coating increases the surface roughness of the fibers, improving the physical bond between the fibers and the matrix material. The addition of antibacterial metal ions endows the UHMWPE fibers with excellent antibacterial properties, broadening the application fields of UHMWPE fibers. Simultaneously, it can further increase the surface roughness of the fibers, which is beneficial for enhancing the physical bond between the fibers and the matrix material and preventing fiber slippage. The three-way weaving design improves the mechanical strength of the ultra-high molecular weight polyethylene fiber monofilament. The regularly arranged uneven surface and numerous gaps on the surface of the monofilament bundle facilitate the physical bonding between the monofilament and the epoxy resin, further improving the bonding strength and effectively overcoming the problem of poor composite strength between ultra-high molecular weight polyethylene fiber and epoxy resin. Attached Figure Description

[0033] Figure 1 This is a SEM image of the fiber after phenol-amine co-deposition in Example 1;

[0034] Figure 2 This is a SEM image of the fiber after metal ion modification in Example 2;

[0035] Figure 3 The antibacterial results are for Examples 2 and 4;

[0036] Figure 4 A schematic diagram illustrating the weaving principle of ultra-high molecular weight polyethylene fiber with a three-dimensional braided structure;

[0037] Figure 5 This is a schematic diagram of a fiber bundle with a three-dimensional braided structure. Detailed Implementation

[0038] The present invention will be further described below with reference to embodiments.

[0039] Example 1

[0040] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0041] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber. Figure 1 This is a SEM image of the fiber after phenol-amine co-deposition.

[0042] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0043] (4) Triaxial weaving of ultra-high molecular weight polyethylene (UHMWPE) fibers: Using a 32-spindle vertical braiding machine, 20 axial yarn fibers are added along the weaving crimp direction. At a gear ratio of 44:88 and a rotation speed of 80 rpm, a triaxially woven UHMWPE fiber bundle is obtained (weaving principle as follows). Figure 4 As shown, fiber bundles with a three-dimensional braided structure are as follows: Figure 5 (As shown).

[0044] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0045] Example 2

[0046] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone with a volume ratio of 1:1 and sonicated for 100 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0047] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0048] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber. Figure 2 This is a SEM image of the fiber after metal ion modification.

[0049] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0050] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0051] Example 3

[0052] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0053] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 50 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0054] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0055] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a speed of 80 rpm.

[0056] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0057] Example 4

[0058] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0059] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0060] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L Cu(NO3)2 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0061] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0062] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0063] Comparative Example 1 (pH too low during phenol-amine co-deposition)

[0064] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0065] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 7. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0066] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0067] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0068] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0069] Comparative Example 2 (pH too high during phenol-amine co-deposition)

[0070] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0071] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L NaOH solution was added to adjust the pH to 13. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0072] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0073] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0074] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0075] Comparative Example 3 (Phenolic amine co-deposition reaction time was too short)

[0076] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0077] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 1 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0078] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0079] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0080] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0081] Comparative Example 4 (relative content of 1,6-hexanediamine was too low)

[0082] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0083] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.1 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0084] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0085] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a speed of 80 rpm.

[0086] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0087] Comparative Example 5 (relative content of 1,6-hexanediamine was too high)

[0088] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0089] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 1 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0090] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0091] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0092] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0093] Comparative Example 6 (Metal ion modification time too short)

[0094] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone with a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0095] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0096] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred for 5min at room temperature. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0097] Comparative Example 7 (Metal ion modification time was too long)

[0098] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0099] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0100] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 10h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0101] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0102] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0103] Comparative Example 8 (without three-way braided structure)

[0104] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0105] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0106] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0107] (4) Preparation of composite material: Place one fiber horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0108] Comparative Example 9 (catechol was replaced with dopamine hydrochloride)

[0109] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0110] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of dopamine hydrochloride and 0.4 g of 1,6-hexanediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0111] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L AgNO3 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0112] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a rotation speed of 80 rpm.

[0113] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0114] Comparative Example 10 (1,6-hexanediamine was replaced with ethylenediamine)

[0115] (1) Pretreatment of ultra-high molecular weight polyethylene fiber: Ultra-high molecular weight polyethylene fiber is placed in a solution of ethanol and acetone in a volume ratio of 1:1 and sonicated for 60 min. After being taken out, it is washed with water and dried at 40℃ to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface.

[0116] (2) Phenolic-amine co-deposition modification: 0.6 g of tris(hydroxymethyl)aminomethane hydrochloride was dissolved in 100 mL of deionized water. After thorough stirring, 1 mol / L dilute hydrochloric acid solution was added to adjust the pH to 8.5. 0.2 g of catechol and 0.4 g of ethylenediamine were added and stirred until dissolved. 0.1 g of the ultra-high molecular weight polyethylene fiber obtained in step (1) was placed in 250 mL of the solution and reacted under shaking conditions for 16 h. The fiber was then removed, washed with water, and dried at 40 °C to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber.

[0117] (3) Metal ion modification: 0.1g of ultra-high molecular weight polyethylene fiber obtained in step (2) was placed in 250mL of 0.07mol / L Cu(NO3)2 solution and stirred at room temperature for 2h. After being taken out and washed with water, it was dried at 40℃ to obtain antibacterial ultra-high molecular weight polyethylene fiber.

[0118] (4) Triaxial weaving of ultra-high molecular weight polyethylene fiber: 20 shaft yarn fibers are added along the weaving curling direction using a 32-spindle vertical weaving machine, and a triaxial weaving structure of ultra-high molecular weight polyethylene fiber bundle is obtained at a gear ratio of 44:88 and a speed of 80 rpm.

[0119] (5) Preparation of composite material: Place one fiber bundle horizontally in a polytetrafluoroethylene mold and keep it taut. Mix epoxy resin and curing agent at a mass ratio of 3:1 and stir evenly. Use a syringe to draw 10 mL of epoxy resin mixture and inject it into the mold. After the epoxy resin is completely cured, ultra-high molecular weight polyethylene fiber composite material is obtained.

[0120] Performance testing

[0121] The materials used in each embodiment and comparative example were tested. The surface morphology of the fibers was observed using scanning electron microscopy (SEM), the chemical elements on the fiber surface were tested using EDS, and the crystallinity of the fibers was characterized using XRD. The specific testing methods for antibacterial properties, interfacial shear strength, and composite material strength are as follows:

[0122] Antibacterial performance test: The antibacterial performance of the fiber samples was tested according to the shaking method in GB / T20944.3-2008. A 67.5cm long fiber sample was mixed with 3mL of bacterial solution (10 6 The bacterial culture (CFU / mL) was co-cultured at 25℃ and 150 rpm for 18 h. The bacterial culture was then diluted and plated, and the antibacterial rate was calculated based on the number of colonies.

[0123] Cytotoxicity test: Sterilized ultra-high molecular weight polyethylene fibers were placed in 96-well plates containing 3T3 cell suspension (200 μL / well, 5000 cells / well) and incubated for 24 h. The culture medium was aspirated, and CCK-8 solution was added to each well, followed by incubation for another 3 h. The absorbance at 450 nm was measured using a PerkinElmer microplate reader for three independent experiments. Cell viability was calculated using the cell viability formula. A cell viability greater than 80% was considered to indicate that the dressing was non-cytotoxic.

[0124] Cell viability (%) = [(A s -A b )-(A c -A b )]×100%

[0125] Among them: A s : Absorbance of the experimental group, A c : Absorbance of control group, A b : Absorbance of the blank group.

[0126] Interfacial shear strength test: A fiber bundle (composed of 35 monofilaments) or a three-dimensional braided fiber bundle is perpendicularly passed through a cylindrical mold. A certain volume of epoxy resin mixture (epoxy resin and curing agent mass ratio of 3:1) is injected into the mold using a syringe, with a resin thickness of approximately 2 mm. The fiber bundle to be tested is kept perpendicular to the epoxy resin plane. After the epoxy resin is completely cured, the fiber is demolded for testing. A CTM2000 universal testing machine is used to pull the fiber out of the epoxy resin at a speed of 10 mm / min. The maximum tensile force during the pull-out process is recorded, and the interfacial shear strength (IFSS) is calculated using the formula: τ = F / πdL

[0127] In the formula: τ is the interfacial shear strength (MPa); F is the maximum tensile force for fiber pull-out (N); d is the fiber diameter (mm); L is the length of the fiber embedded in the resin (mm). Ten groups of samples were measured, and their average value and error were calculated.

[0128] Composite material strength testing: Following GB / T2567-2008 standard, fiber bundles (35 monofilaments) or triaxial braided fiber bundles were horizontally placed in a polytetrafluoroethylene dumbbell-shaped mold to prepare epoxy resin-based composite materials. The samples were clamped at both ends on a universal testing machine, with a tensile rate of 10 mm / min. Five sets of samples were measured, and their average value and error were calculated.

[0129] The test results are shown in the table below:

[0130]

[0131] The results in the table show that by utilizing the Michael addition or Schiff base reaction between catechol and 1,6-hexanediamine to modify the coating of ultra-high molecular weight polyethylene (UHMWPE) fibers, and through the bonding of metal ions with the fibers, UHMWPE fibers with high bonding strength and excellent antibacterial properties were successfully prepared to improve the mechanical strength of fiber / epoxy resin composites (Examples 1-4). Figure 3 Example 2 (Ag) + ) and Example 4 (Cu 2+ The antibacterial results are shown in the figure.

[0132] If the pH during phenol-amine co-deposition is too low (Comparative Example 1), catechol cannot form a quinone structure, resulting in the inability to form a coating. Metal ions cannot bind to the coating through coordination bonds, leading to the fiber lacking excellent interfacial shear strength and antibacterial properties. If the pH during phenol-amine co-deposition is too high (Comparative Example 2), it may cause some damage to ultra-high molecular weight polyethylene, resulting in poor interfacial shear strength and the mechanical strength of the composite material.

[0133] If the co-deposition time of phenolamine is too short (Comparative Example 3), a coating of a certain thickness cannot be formed on the fiber surface, thus failing to bind metal ions, resulting in poor mechanical strength and antibacterial properties of the fiber.

[0134] If the relative content of 1,6-hexanediamine is too low (Comparative Example 4), coating formation is hindered, the number of metal ion binding sites decreases, and there are too few reaction sites between the modified fiber and epoxy resin, resulting in poor interfacial shear strength and mechanical strength of the composite material, as well as poor antibacterial properties. If the relative content of 1,6-hexanediamine is too high (Comparative Example 5), the coating surface has more amino groups, increasing the number of metal ion binding sites, but the degree of crosslinking of the coating is lower, the bonding force between the coating and the fiber weakens, and the interfacial strength of the coating decreases, resulting in poor interfacial shear strength between the fiber and epoxy resin.

[0135] If the modification time of metal ions is too short (Comparative Example 6), fewer metal ions are bound to the fiber surface, reducing the antibacterial properties of the fiber. Simultaneously, the fiber roughness decreases, and the physical bonding force between the fiber and epoxy resin weakens, resulting in poor interfacial shear strength and the mechanical strength of the composite material. If the modification time of metal ions is too long (Comparative Example 7), the content of metal atoms on the fiber surface increases, slightly improving the interfacial shear strength and the mechanical strength of the composite material. However, this increases the cytotoxicity of the fiber, limiting the application of ultra-high molecular weight polyethylene fibers in the field of biomaterials.

[0136] If the ultra-high molecular weight polyethylene fibers in the composite material do not have a triaxial braided structure (Comparative Example 8), the fiber bundles are in direct contact with the epoxy resin matrix material. There is no void structure in the braided fiber bundles, and the composite can only rely on the coating and epoxy resin. This cannot significantly improve the bonding strength of the fiber bundles and the mechanical strength of the composite material.

[0137] If catechol is replaced by dopamine hydrochloride containing ortho-phenolic hydroxyl groups (Comparative Example 9), the dopamine hydrochloride will self-polymerize into dopamine on the fiber surface, resulting in a reduction of reaction sites with 1,6-hexanediamine, which leads to a decrease in the mechanical strength of the composite material and may increase the cost. If 1,6-hexanediamine is replaced by ethylenediamine (Comparative Example 10), the reactivity is increased, the reaction rate is too fast, resulting in uneven coating and a decrease in the mechanical strength of the composite material.

[0138] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0139] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-strength ultra-high molecular weight polyethylene fiber composite material, characterized in that... include: (1) The surface of ultra-high molecular weight polyethylene fiber is cleaned to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface. (2) Dissolve 0.4-0.8g of tris(hydroxymethyl)aminomethane hydrochloride in 100mL of water, stir thoroughly, adjust the pH to alkaline, add 0.15-0.25g of catechol and 0.2-0.4g of 1,6-hexanediamine and stir until dissolved; place ultra-high molecular weight polyethylene fiber in the obtained solution at a bath ratio of 1g:(2300-2700)mL and shake to react, take it out, wash with water and dry it to obtain phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber; (3) Place the phenol-amine co-deposition modified ultra-high molecular weight polyethylene fiber in a solution containing 0.05-0.09 mol / L antibacterial metal ions at a bath ratio of 1 g: (2300-2700) mL and stir at room temperature. After taking it out, wash it with water and dry it to obtain antibacterial ultra-high molecular weight polyethylene fiber. (4) The antibacterial ultra-high molecular weight polyethylene fiber is woven into a three-dimensional braided structure ultra-high molecular weight polyethylene fiber bundle; (5) Place the triaxial braided ultra-high molecular weight polyethylene fiber bundle horizontally in the mold and straighten it. Inject the mixture of uncured epoxy resin and curing agent into the mold. After curing, a high-strength ultra-high molecular weight polyethylene fiber composite material is obtained.

2. The preparation method according to claim 1, characterized in that: Step (1) specifically includes: placing ultra-high molecular weight polyethylene fiber into a mixed solution of ethanol and acetone and sonicating it, then taking it out, washing it with water, and drying it to obtain ultra-high molecular weight polyethylene fiber with no impurities on the surface; the volume ratio of ethanol to acetone is 1:(0.5-1), the sonication time is 60-120 min, and the drying temperature is 40-70℃.

3. The preparation method according to claim 1, characterized in that: In step (2), the adjusted pH is 8-9.

4. The preparation method according to claim 1, characterized in that: In step (2), the reaction time is 14-20 h and the drying temperature is 40-70℃.

5. The preparation method according to claim 1, characterized in that: In step (3), the solution containing antibacterial metal ions is AgNO3 solution, Cu(NO3)2 solution, or C4H solution. 10 OZn solution; The stirring time is 1-4 hours, and the drying temperature is 40-70℃.

6. The preparation method according to claim 1, characterized in that: Step (4) specifically includes: using a 32-spindle vertical braiding machine to add axial yarn fibers along the braiding curl direction, and obtaining a three-way braided structure of ultra-high molecular weight polyethylene fiber bundles under a certain gear ratio and rotation speed.

7. The preparation method according to claim 6, characterized in that: In step (4), The number of yarn fibers is 20-50. The gear ratio is (driving gear: driven gear) = (30-44):88, and the rotational speed is 40-80 rpm.

8. The preparation method according to claim 1, characterized in that: In step (5), the ratio of the amount of ultra-high molecular weight polyethylene fiber bundle to the amount of uncured matrix material is (1-5) bundles: 10 mL.

9. The preparation method according to claim 1, characterized in that: In step (5), the mass ratio of the epoxy resin to the curing agent is 3:(1-1.5).

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