CN114059347B - Surface modification method for improving combination property of ultra-high molecular weight polyethylene fiber and matrix resin - Google Patents

Abstract

The invention relates to the field of polymer materials, and discloses a surface modification method for improving the bonding between ultra-high molecular weight polyethylene fiber and matrix resin. The invention combines plasma technology with inorganic nanoparticle doping technology to perform surface modification on ultra-high molecular weight polyethylene fiber. Firstly, the surface of UHMWPE fiber is activated by plasma, then reacted with silane coupling agent to introduce active groups on the surface, and then reacted with inorganic nanoparticles treated with silane coupling agent, so that the roughness of the fiber surface can be greatly increased without affecting the characteristics of the UHMWPE fiber itself, thereby improving the interface bonding strength when the fiber is used in combination with other resin matrices.

Description

A surface modification method for improving the bonding between ultra-high molecular weight polyethylene fiber and matrix resin

Technical Field

The invention relates to the field of polymer materials, and in particular to a surface modification method for improving the bonding between ultra-high molecular weight polyethylene fibers and matrix resins.

Background Art

Ultra-high molecular weight polyethylene (UHMWPE) fiber is a high-performance fiber with high strength and high modulus that appeared after carbon fiber and aramid fiber. It uses ultra-high molecular weight polyethylene as raw material and can be prepared by high-pressure solid extrusion, plasticized melt spinning, surface crystal growth, ultra-stretching or local ultra-stretching, gel spinning-hot stretching and other processes. The relative molecular mass of UHMWPE is 1 to 6 million, the molecular shape is a linear straight chain structure, the orientation degree is close to 100%, the strength is equivalent to about 15 times that of high-quality steel, 2 times higher than carbon fiber, and 40% higher than aramid. It also has excellent properties such as resistance to ultraviolet radiation, chemical corrosion, high specific energy absorption, low dielectric constant, high electromagnetic wave transmittance, low friction coefficient, and outstanding impact resistance and cutting resistance. Therefore, UHMWPE fiber is an ideal material for making soft bulletproof clothing, stab-proof clothing, lightweight bulletproof helmets, bulletproof armor for money transporters, bulletproof armor for helicopters, lightweight high-pressure containers, aerospace structures, fishing nets, racing boats, sailboats, etc.

However, since UHMWPE fiber itself is a linear long chain formed by non-polar methylene, there is no strong intermolecular force between fiber molecules, and the fiber surface is chemically inert, making it difficult to form chemical bonds with the resin. The high degree of crystallization and orientation produced by high-multiple stretching during production makes the fiber surface very smooth. The combined effect of all these factors makes the surface energy of the fiber very small, and it is difficult to form a good interface bonding when used in combination with other materials, which greatly limits the application of UHMWPE fiber in the field of composite materials, especially lightweight structural materials. Therefore, it is very necessary to modify the surface of UHMWPE fiber.

Summary of the invention

In order to solve the above technical problems, the present invention provides a surface modification method for improving the bonding between ultra-high molecular weight polyethylene fiber and matrix resin. The present invention combines plasma technology with inorganic nanoparticle doping technology to perform surface modification on ultra-high molecular weight polyethylene fiber. First, the surface of UHMWPE fiber is activated by plasma, then reacted with silane coupling agent to introduce active groups on the surface, and then reacted with inorganic nanoparticles treated with silane coupling agent, which can greatly increase the roughness of the fiber surface without affecting the characteristics of the UHMWPE fiber itself, thereby improving the interface bonding strength when the fiber is used in combination with other resin matrices.

The specific technical scheme of the present invention is: a surface modification method for improving the bonding between ultra-high molecular weight polyethylene fiber and matrix resin, comprising the following steps:

(1) Ultra-high molecular weight polyethylene (UHMWPE) fibers were immersed in ethanol for ultrasonic cleaning and then dried.

This step is mainly to clean the impurities on the UHMWPE fiber.

(2) The fiber obtained in step (1) is subjected to plasma treatment, and the treatment conditions are: power 10-200 W, gas flux 0.5-5 L/min, pressure 15-30 Pa, and treatment time 0.5-5 min.

(3) Immersing the fiber obtained in step (2) in an ethanol/water mixed solution containing a silane coupling agent, taking it out after reacting for 1 to 5 hours, and performing a dehydration condensation reaction at 90-130° C. for 0.5 to 3 hours.

(4) Ultrasonic dispersion of large-size inorganic nanoparticles in a mixed solution of water and anhydrous ethanol is performed, and the obtained dispersion is then added dropwise to an ethanol/water mixed solution containing a silane coupling agent for modification to obtain a modified solution of large-size inorganic nanoparticles.

(5) adding the fibers obtained in step (3) to the modified liquid of large-diameter inorganic nanoparticles obtained in step (4) and stirring to react, and taking out and drying after the reaction.

(6) Ultrasonic dispersion of small-sized inorganic nanoparticles in a mixed solution of water and anhydrous ethanol is performed, and the obtained dispersion is then added dropwise to an ethanol/water mixed solution containing a silane coupling agent for modification to obtain a modified solution of small-sized inorganic nanoparticles.

(7) adding the fiber obtained in step (5) to the small-size inorganic nanoparticle modification liquid obtained in step (6) and stirring the mixture for reaction, taking the mixture out and drying it after the reaction to obtain a surface-modified ultra-high molecular weight polyethylene fiber.

In the above surface modification process, the present invention first activates the surface of UHMWPE fiber with plasma to generate active groups such as hydroxyl and carboxyl on the surface of inert fiber; then grafts these active groups with silane coupling agent to further introduce silane coupling groups, and finally acts on the fiber with inorganic nanoparticles treated with silane coupling agent to graft inorganic nanoparticles. These inorganic nanoparticles are distributed on the fiber surface to form a rough surface, which greatly improves the roughness of the fiber surface. Therefore, when the fiber is composited with the matrix resin, due to the "meshing" effect of the inorganic particles and the chemical bond effect of the silane coupling agent, the interface bonding strength between the fiber and the matrix resin can be significantly improved while maintaining the mechanical properties of the original fiber.

Preferably, in step (1), the mass ratio of the ultra-high molecular weight polyethylene fiber to ethanol is 1:20-1:50.

Preferably, in step (1), the ultrasonic cleaning time is 20-40 min; and the drying temperature is 50-70°C.

Preferably, in step (2), the atmosphere for plasma treatment contains at least oxygen, and the oxygen content is greater than 15% by volume. The technical effect is better at the above oxygen content. If the oxygen content is too low, the plasma treatment method will produce fewer active groups such as hydroxyl and carboxyl groups on the fiber surface, which will affect the degree of reaction with the silane coupling agent in the subsequent steps. Preferably, in steps (3), (4) and (6), the silane coupling agent is one or more of KH550, KH560 and KH570; the concentration of the silane coupling agent is 1 to 10wt%.

Preferably, in steps (3), (4) and (6), the mass ratio of ethanol to water in the ethanol/water mixed solution is 1:0-0:1.

Preferably, in steps (4) and (6): the particle size of the large-diameter inorganic nanoparticles is 200 to 500 nm; and the particle size of the small-diameter inorganic nanoparticles is 10 to 100 nm.

The team of the present invention found in the research process that if only inorganic nanoparticles are introduced on the surface of UHMWPE fibers, the degree of improvement in the bonding between the fibers and the matrix resin is still limited. To this end, the present invention uses two nanoparticles of different size ranges to attach to the surface of UHMWPE fibers one after another, which can form anchor points with staggered distribution of large and small particle sizes, which can further improve the roughness of the fiber surface compared to inorganic nanoparticles with a single particle size distribution. At the same time, we also found that the size of large-size inorganic nanoparticles should not be too large, otherwise their stability on the fiber is poor, they are easy to fall off, and affect the interfacial bonding strength.

Preferably, in steps (4) and (6), the large-size inorganic nanoparticles or small-size inorganic nanoparticles include one or more of silicon dioxide nanoparticles, titanium dioxide nanoparticles, zirconium oxide nanoparticles, aluminum oxide nanoparticles, calcium carbonate nanoparticles, montmorillonite, graphene and carbon nanotubes.

Preferably, in steps (4) and (6), the dispersion is added at a rate of 1 to 10 mL/min. The modification conditions are: a temperature of 40 to 60° C. and a stirring speed of 100 to 1000 r/min.

Preferably, in steps (5) and (7), the reaction temperature is 40-60°C, and the reaction time is 1-12 hours; the drying temperature is 90-130°C, and the drying time is 0.5-3 hours.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The present invention first activates the surface of UHMWPE fiber with plasma, so that the fiber surface carries a large number of active groups; then, these active groups are grafted with silane coupling agents to further introduce active groups, and finally, the fiber is acted with inorganic nanoparticles treated with silane coupling agents to graft inorganic nanoparticles. These inorganic nanoparticles are distributed on the fiber surface to form a rough surface, which greatly improves the roughness of the fiber surface. Therefore, when the fiber is composited with the matrix resin, due to the "meshing" effect of the inorganic particles and the chemical bonding effect of the silane coupling agent, the interfacial bonding strength between the fiber and the matrix resin can be significantly improved while maintaining the mechanical properties of the original fiber.

(2) The present invention further uses two nanoparticles of different particle size ranges to attach to the surface of the UHMWPE fiber in sequence, thereby forming staggered anchor points. Compared with inorganic nanoparticles of a single particle size distribution, the roughness of the fiber surface can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an electron microscope image of the surface of UHMWPE fiber after treatment by different treatment methods; wherein: Figure 1(a) is an untreated UHMWPE fiber; Figure 1(b) is an UHMWPE fiber treated by step (3) of Example 1; Figure 1(c) is an UHMWPE fiber treated by step (7) of Example 1.

DETAILED DESCRIPTION

The present invention will be further described below in conjunction with embodiments.

Example 1

(1) 10 g of UHMWPE fiber was soaked in 200 ml of ethanol, ultrasonically cleaned for 30 min, and then dried in an oven at 60 °C;

(2) Plasma treatment step (1) The cleaned UHMWPE fiber was treated under the following conditions: power 30 W, treatment gas: air, gas flux 1.5 L/min, pressure 25 Pa, treatment for 3 min;

(3) placing the UHMWPE fiber treated in step (2) into an ethanol solution containing 3 wt% KH550, taking it out after reacting for 3 h, rinsing it with deionized water, and placing it in a 110° C. oven for dehydration condensation reaction for 1 h;

(4) 1.2 g of 300±30 nm large-size silica nanoparticles were ultrasonically dispersed in 50 ml of ethanol/water mixed solution (v:v=9:1), and then the solution was added dropwise to 5 wt% KH550 ethanol/water mixed solution (v:v=9:1) at a rate of 1 ml/min, and the reaction was stirred for 12 h at a reaction temperature of 55°C;

(5) placing the fiber obtained in step (3) into the inorganic nanoparticle dispersion obtained in step (4) and stirring the mixture at 50° C. for 6 h, taking the mixture out and placing it in a 110° C. oven for drying for 1 h;

(6) 1.2 g of 30±10 nm large-size silica nanoparticles were ultrasonically dispersed in 50 ml of ethanol/water mixed solution (v:v=9:1), and then the solution was added dropwise to 5 wt% KH550 ethanol/water mixed solution (v:v=9:1) at a rate of 1 ml/min, and the mixture was stirred for 12 h at a reaction temperature of 55°C;

(7) The fiber in step (5) was placed in the inorganic nanoparticle dispersion obtained in step (6) and stirred at 50° C. for 6 h. After being taken out, it was placed in an oven at 110° C. for 2 h to obtain a surface-modified UHMWPE fiber.

Figure 1 is a scanning electron microscope image of the surface of UHMWPE fiber after treatment by different treatment methods; wherein: Figure 1 (a) is an untreated UHMWPE fiber; Figure 1 (b) is an UHMWPE fiber treated by step (3) of Example 1; Figure 1 (c) is an UHMWPE fiber treated by step (7) of Example 1. It can be seen from the figure that the surface of the untreated UHMWPE fiber is very smooth, so its interaction with other resin matrices in the preparation process of the composite material is relatively weak. After the plasma treatment in step (3), the roughness of the fiber surface increases slightly, while after the treatment in step (7), the roughness of the fiber surface increases significantly, with both fine granular modified points and sheet-like modified areas, which greatly improves the interaction strength with other resin matrices.

Example 2

(1) 10 g of UHMWPE fiber was soaked in 350 ml of ethanol, ultrasonically cleaned for 30 min, and then dried in an oven at 60 °C;

(2) Plasma treatment of the cleaned UHMWPE fiber in step (1), treatment conditions: power 200 W, treatment gas: air, gas flux 5 L/min, pressure 30 Pa, treatment 0.5 min;

(3) placing the UHMWPE fiber treated in step (2) into an aqueous solution containing 10 wt% KH550, taking it out after reacting for 5 hours, rinsing it with deionized water, and placing it in an oven at 110° C. for dehydration condensation reaction for 2 hours;

(4) 1.2 g of titanium dioxide nanoparticles with a large particle size of 250 ± 20 nm were ultrasonically dispersed in 50 ml of aqueous solution, and the solution was then added dropwise to a 10 wt % KH550 aqueous solution at 5 ml/min, and the reaction was stirred for 3 h at a reaction temperature of 55°C;

(5) placing the fiber obtained in step (3) into the inorganic nanoparticle dispersion obtained in step (4) and stirring the mixture at 45° C. for 12 h, taking the mixture out and placing it in a 120° C. oven for drying for 1 h;

(6) 1.2 g of 15±5 nm large-size silica nanoparticles were ultrasonically dispersed in 50 ml of aqueous solution, and the solution was then added dropwise to a 10 wt % KH550 aqueous solution at 6 ml/min, and the reaction was stirred for 12 h at a reaction temperature of 55°C;

(7) The fiber in step (5) was placed in the inorganic nanoparticle dispersion obtained in step (6) and stirred at 55° C. for 8 h. After being taken out, it was placed in an oven at 110° C. for drying for 2 h to obtain surface-modified UHMWPE fiber.

Example 3

(1) 10 g of UHMWPE fiber was soaked in 500 ml of ethanol, ultrasonically cleaned for 30 min, and then dried in an oven at 60 °C;

(2) Plasma treatment step (1) The cleaned UHMWPE fiber was treated under the following conditions: power 10 W, treatment gas was a mixture of oxygen and nitrogen, wherein oxygen accounted for 60% by volume, gas flux was 0.5 L/min, pressure was 15 Pa, and treatment time was 5 min;

(3) placing the UHMWPE fiber treated in step (2) into an ethanol solution containing 1 wt% KH550, taking it out after reacting for 5 hours, rinsing it with deionized water, and placing it in a 110° C. oven for dehydration condensation reaction for 3 hours;

(4) 1.2 g of titanium dioxide nanoparticles with a large particle size of 450 ± 50 nm were ultrasonically dispersed in 50 ml of ethanol solution, and then the solution was added dropwise to 1 wt% KH550 ethanol solution at 3 ml/min, and the reaction was stirred for 12 h at a reaction temperature of 40°C;

(5) placing the fiber obtained in step (3) into the inorganic nanoparticle dispersion obtained in step (4) and stirring the mixture at 40° C. for 12 h, taking the mixture out and placing it in a 90° C. oven for drying for 3 h;

(6) 1.2 g of 80±15 nm small-particle titanium dioxide nanoparticles were ultrasonically dispersed in 50 ml of ethanol solution, and then the solution was added dropwise to 10 wt% KH550 ethanol solution at 10 ml/min, and the reaction was stirred for 1 h at a reaction temperature of 55°C;

(7) The fiber in step (5) was placed in the inorganic nanoparticle dispersion obtained in step (6) and stirred at 60° C. for 1 h. After being taken out, it was placed in an oven at 110° C. for 2 h to obtain a surface-modified UHMWPE fiber.

Comparative Example 1 (Modification using only a single large-size inorganic nanoparticle)

(1) 10 g of UHMWPE fiber was soaked in 200 ml of ethanol, ultrasonically cleaned for 30 min, and then dried in an oven at 60 °C;

(2) Plasma treatment step (1) The cleaned UHMWPE fiber was treated under the following conditions: power 30 W, treatment gas: air, gas flux 1.5 L/min, pressure 25 Pa, treatment for 3 min;

(3) placing the UHMWPE fiber treated in step (2) into an ethanol solution containing 3 wt% KH550, taking it out after reacting for 3 h, rinsing it with deionized water, and placing it in a 110° C. oven for dehydration condensation reaction for 1 h;

(4) 2.4 g of 300±30 nm large-size silica nanoparticles were ultrasonically dispersed in 50 ml of ethanol/water mixed solution (v:v=9:1), and then the solution was added dropwise to 5 wt% KH550 ethanol/water mixed solution (v:v=9:1) at a rate of 1 ml/min, and the reaction was stirred for 12 h at a reaction temperature of 55°C;

(5) The fiber obtained in step (3) was placed in the inorganic nanoparticle dispersion obtained in step (4) and stirred at 50° C. for 12 h. After being taken out, it was placed in an oven at 110° C. for 2 h to obtain a surface-modified UHMWPE fiber.

Comparative Example 2 (modification using only a single small-size inorganic nanoparticle)

(1) 10 g of UHMWPE fiber was soaked in 200 ml of ethanol, ultrasonically cleaned for 30 min, and then dried in an oven at 60 °C;

(2) Plasma treatment step (1) The cleaned UHMWPE fiber was treated under the following conditions: power 30 W, treatment gas: air, gas flux 1.5 L/min, pressure 25 Pa, treatment for 3 min;

(3) placing the UHMWPE fiber treated in step (2) into an ethanol solution containing 3 wt% KH550, taking it out after reacting for 3 h, rinsing it with deionized water, and placing it in a 110° C. oven for dehydration condensation reaction for 1 h;

(4) 2.4 g of 30±10 nm small-particle silica nanoparticles were ultrasonically dispersed in 50 ml of ethanol/water mixed solution (v:v=9:1), and then the solution was added dropwise to 5 wt% KH550 ethanol/water mixed solution (v:v=9:1) at 1 ml/min, and the reaction was stirred for 12 h at a reaction temperature of 55°C;

(5) The fiber in step (5) is placed in the inorganic nanoparticle dispersion obtained in step (4) and stirred at 50° C. for 12 h. After being taken out, the fiber is placed in an oven at 110° C. for 2 h to obtain a surface-modified UHMWPE fiber.

Comparative Example 3 (First treat small-size nanoparticles and then treat large-size nanoparticles)

(1) 10 g of UHMWPE fiber was soaked in 200 ml of ethanol, ultrasonically cleaned for 30 min, and then dried in an oven at 60 °C;

(2) Plasma treatment step (1) The cleaned UHMWPE fiber was treated under the following conditions: power 30 W, treatment gas: air, gas flux 1.5 L/min, pressure 25 Pa, treatment for 3 min;

(3) placing the UHMWPE fiber treated in step (2) into an ethanol solution containing 3 wt% KH550, taking it out after reacting for 3 h, rinsing it with deionized water, and placing it in a 110° C. oven for dehydration condensation reaction for 1 h;

(4) 1.2 g of 30±10 nm large-size silica nanoparticles were ultrasonically dispersed in 50 ml of ethanol/water mixed solution (v:v=9:1), and then the solution was added dropwise to 5 wt% KH550 ethanol/water mixed solution (v:v=9:1) at a rate of 1 ml/min, and the mixture was stirred for 12 h at a reaction temperature of 55°C;

(5) placing the fiber obtained in step (3) into the inorganic nanoparticle dispersion obtained in step (4) and stirring the mixture at 50° C. for 6 h, taking the mixture out and placing it in a 110° C. oven for drying for 1 h;

(6) 1.2 g of 300±30 nm large-size silica nanoparticles were ultrasonically dispersed in 50 ml of ethanol/water mixed solution (v:v=9:1), and then the solution was added dropwise to 5 wt% KH550 ethanol/water mixed solution (v:v=9:1) at a rate of 1 ml/min, and the reaction was stirred for 12 h at a reaction temperature of 55°C;

(7) The fiber in step (5) was placed in the inorganic nanoparticle dispersion obtained in step (6) and stirred at 50° C. for 6 h. After being taken out, it was placed in an oven at 110° C. for 2 h to obtain a surface-modified UHMWPE fiber.

Interface bond strength test

Take a bundle of surface-modified UHMWPE fibers obtained in Examples 1-3 and Comparative Examples 1-2 respectively, bury them vertically in a mixed solution of E51 epoxy resin and curing agent (resin: curing agent mass ratio is 3:1) and cure them at room temperature for 12 hours. Use an Instron universal material testing machine to clamp the resin matrix with a clamp, clamp one end of the fiber and continuously increase the force perpendicular to the resin matrix to stretch it. The stretching speed is 10 mm/min until the fiber is pulled out of the resin matrix. The force Fd at the moment of fiber debonding is recorded, and the interfacial bonding strength is calculated according to the following formula: Where L is the fiber length and R is the fiber diameter. The results are shown in the following table:

sample Interface bonding strength (MPa/mm ² ) UHMWPE fiber 0.518 Example 1 2.169 Example 2 1.972 Example 3 2.021 Comparative Example 1 1.213 Comparative Example 2 1.145 Comparative Example 3 1.578

As can be seen from the above table, the surface of the untreated UHMWPE fiber is very smooth, and its interfacial bonding strength with the epoxy resin is low, while the surface roughness of the UHMWPE fiber treated with large and small particle size inorganic nanoparticles is greatly increased, and its interfacial bonding strength with the epoxy resin is greatly improved (Examples 1-3); and the surface roughness of the UHMWPE fiber treated with large or small particle size inorganic nanoparticles alone (Comparative Examples 1 and 2) is also increased, but the roughness is not as hierarchical as that after the large and small particle size inorganic nanoparticles are used in combination, so the increase in interfacial bonding strength is not as good as the latter. It should also be pointed out that the modification order of the nanoparticles will also affect the interfacial bonding strength. Although the interfacial bonding strength of the UHMWPE fiber modified with small particle size nanoparticles first and then with large particle size nanoparticles is higher than that of the fiber modified with single size nanoparticles, there is still a certain gap with the interfacial bonding strength of the fiber modified with large particle size nanoparticles first and then with small particle size nanoparticles. This may be because the treatment method of first treating large particles and then small particles allows small-size nanoparticles to be embedded in the unmodified areas of large particles, forming a staggered roughness on the fiber surface. If the small particles are treated first and then large particles, the small particles may occupy most of the space on the fiber surface, resulting in the large-size nanoparticles being only sparsely distributed on it, which ultimately affects the interfacial bonding strength.

The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art.

The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims (6)

1. A surface modification method for improving the combination property of ultra-high molecular weight polyethylene fiber and matrix resin is characterized by comprising the following steps:

(1) Soaking ultra-high molecular weight polyethylene fibers in ethanol, ultrasonically cleaning, and drying;

(2) Performing plasma treatment on the fiber obtained in the step (1), wherein the treatment conditions are as follows: the power is 10-200W, the gas flux is 0.5-5L/min, the pressure is 15-30 Pa, and the treatment time is 0.5-5 min;

(3) Immersing the fiber obtained in the step (2) in an ethanol/water mixed solution containing a silane coupling agent, reacting for 1-5 h, taking out, and performing dehydration condensation reaction for 0.5-3 h at 90-130 ℃;

(4) Dispersing large-particle-size inorganic nano particles with the particle size of 200-500 nm in a mixed solution of water and absolute ethyl alcohol by ultrasonic, and then dripping the obtained dispersion into an ethanol/water mixed solution containing a silane coupling agent for modification treatment to obtain large-particle-size inorganic nano particle modified liquid;

(5) Adding the fiber obtained in the step (3) into the large-particle-size inorganic nanoparticle modified liquid obtained in the step (4), stirring for reaction, reacting for 1-12 h at 40-60 ℃, taking out, and drying for 0.5-3 h at 90-130 ℃;

(6) Ultrasonically dispersing small-particle-size inorganic nano particles with the particle size of 10-100 nm in a mixed solution of water and absolute ethyl alcohol, and then dripping the obtained dispersion into an ethanol/water mixed solution containing a silane coupling agent for modification treatment to obtain small-particle-size inorganic nano particle modified liquid;

(7) Adding the fiber obtained in the step (5) into the small-particle-size inorganic nanoparticle modified liquid obtained in the step (6), stirring and reacting, taking out the fiber after reacting for 1-12 hours at 40-60 ℃, and drying for 0.5-3 hours at 90-130 ℃ to obtain the surface modified ultra-high molecular weight polyethylene fiber;

In steps (3), (4) and (6): the silane coupling agent is one or more of KH550, KH560 and KH 570; the concentration of the silane coupling agent is 1-10wt%; the mass ratio of the ethanol to the water in the ethanol/water mixed solution is 1:0-0:1.

2. The surface modification method according to claim 1, wherein in the steps (4) and (6): the dropping speed of the dispersion liquid is 1-10 mL/min; the modification conditions are as follows: the temperature is 40-60 ℃, and the stirring speed is 100-1000 r/min.

3. The surface modification method according to claim 1, wherein in the step (1): the mass ratio of the ultra-high molecular weight polyethylene fiber to the ethanol is 1:20-1:50.

4. The surface modification method according to claim 1, wherein in the step (1):

the ultrasonic cleaning time is 20-40min;

the drying temperature is 50-70 ℃.

5. The surface modification method according to claim 1, wherein in the step (2): the atmosphere in which the plasma treatment is performed contains at least oxygen, and the content of oxygen is more than 15% by volume.

6. The surface modification method according to claim 1, wherein in the steps (4) and (6): the large-particle-size inorganic nanoparticles or small-particle-size inorganic nanoparticles comprise one or more of silica nanoparticles, titania nanoparticles, zirconia nanoparticles, alumina nanoparticles, calcium carbonate nanoparticles, montmorillonite, graphene and carbon nanotubes.