CN117228974A - Grafting modification method of basalt fiber - Google Patents

Abstract

The invention provides a graft modification method of basalt fiber and relates to the technical field of basalt fiber modification. The method includes the following steps: etching basalt fibers to obtain etched basalt fibers; mixing graft suspension and silane coupling agent solution to obtain a modified solution; grafts in the graft suspension include Nano-attapulgite or nano-silica; mix the obtained etched basalt fiber with the obtained modified solution and then perform a grafting reaction to obtain a grafted basalt fiber. The grafted basalt fiber obtained by the graft modification method provided by the invention has high oil absorption rate.

Description

A grafting modification method of basalt fiber

Technical field

The present invention relates to the technical field of basalt fiber modification, and in particular to a graft modification method of basalt fiber.

Background technique

Long-life asphalt pavement is an important development direction in the field of road engineering, and durable asphalt pavement materials are an important link in achieving long-life asphalt pavement. In order to improve the durability and service level of asphalt pavement, scientific researchers have conducted a lot of research on asphalt pavement materials. Adding fibers to asphalt mixtures to make them become fiber-reinforced composite materials is an important means to achieve the durability of asphalt pavement materials.

Basalt fiber (BF) has many excellent properties such as high tensile strength, large elastic modulus, corrosion resistance, combustion resistance, and high temperature resistance. It is known as the "green industrial material" in the 21st century. Because basalt fiber is a continuous fiber formed by high-temperature melting of basalt parent rock and high-speed drawing of a platinum-rhodium alloy drawing plate, its surface is smooth, low surface energy, chemically inert, weak in adsorption capacity with asphalt, and weak in interface bonding strength. etc., it is difficult to give full play to the excellent mechanical properties of basalt fiber.

Contents of the invention

In order to solve the above problems, the present invention provides a graft modification method of basalt fiber, which can improve the oil absorption rate of basalt fiber and the bonding strength of the interface with asphalt and other properties.

In order to achieve the above objects, the present invention provides the following technical solutions:

The invention provides a graft modification method of basalt fiber, which includes the following steps:

1) Etch basalt fibers to obtain etched basalt fibers;

2) Mix the graft suspension and the silane coupling agent solution to obtain a modified solution;

The grafts in the graft suspension include nano-attapulgite or nano-silica;

3) Mix the etched basalt fiber obtained in step 1) with the modified solution obtained in step 2) and then perform a grafting reaction to obtain grafted basalt fiber.

Preferably, the reagent used in step 1) etching includes sodium hydroxide solution or hydrochloric acid solution;

The concentration of the sodium hydroxide solution is 3 to 5 mol/L;

The concentration of the hydrochloric acid solution is 3 to 5 mol/L.

Preferably, the volume ratio of the mass of the basalt fiber to the reagent is 1g:20ml;

The etching conditions include: immersion treatment at a temperature of 60°C for 1 hour.

Preferably, the method for preparing the graft suspension in step 2) includes: mixing the graft and the ethanol solution, stirring and ultrasonic to obtain the graft suspension;

The volume ratio of the mass of the graft to the ethanol solution is 1g:100ml;

The volume ratio of ethanol and water in the ethanol solution is 9:1;

The stirring time is 30 minutes, and the ultrasonic time is 1 hour.

Preferably, the step 1) basalt fiber is pre-treated and then etched;

The pretreatment conditions include: immersing the basalt fiber in an acetone solution for ultrasonic cleaning and drying;

The mass percentage of the acetone solution is 20%;

The ultrasonic cleaning time is 1 hour;

The drying temperature is 100°C.

Preferably, the method for preparing the silane coupling agent solution in step 2) includes: mixing and stirring the silane coupling agent and the ethanol solution to obtain a silane coupling agent solution.

Preferably, the volume ratio of ethanol and water in the ethanol solution is 9:1.

Preferably, the volume ratio of the silane coupling agent to the ethanol solution is 20:500;

The stirring conditions include: temperature of 25°C, time of 1 hour, and rotation speed of 400 r/min.

Preferably, the silane coupling agent includes silane coupling agent KH550.

Preferably, the volume ratio of step 2) graft suspension and silane coupling agent solution is 100:520;

The mixing conditions include: time is 1h, rotation speed is 120r/min.

Preferably, the conditions for the grafting reaction in step 3) include: temperature of 25-30°C, time of 3 hours, and rotation speed of 120 r/min.

Beneficial effects:

Compared with the original basalt fiber, the ability of ATP-grafted basalt fiber to absorb asphalt is increased by 69.7%, indicating that ATP-grafted basalt fiber has better compatibility and wettability with asphalt, and can effectively increase the amount of asphalt in the mixture and strengthen the Performance of asphalt pavements;

The ability of SiO ₂ grafted basalt fiber to absorb asphalt is 42.1% higher than that of the original basalt fiber, indicating that nano-SiO ₂ grafted basalt fiber has better compatibility and wettability with asphalt and can effectively increase the asphalt content in the mixture. Dosage to enhance the performance of asphalt pavement.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the embodiments will be briefly introduced below.

Figure 1 is a schematic diagram of the grafting principle of nano-attapulgite;

Figure 2 is a schematic diagram of the grafting principle of nano-silica;

Figure 3a is the original BF (×500) electron microscope scanning image;

Figure 3b is the original BF (×3000) electron microscope scanning image;

Figure 3c is an ATP-BF (×500) electron microscope scanning image;

Figure 3d is an ATP-BF (×3000) electron microscope scanning image;

Figure 3e is the original ATP-BF (×10000) electron microscope scanning image;

Figure 3f shows the ATP-BF (×30000) electron microscope scanning image;

Figure 4a is the original BF (×500) electron microscope scanning image;

Figure 4b is the original BF (×3000) electron microscope scanning image;

Figure 4c is a scanning electron microscope image of SiO ₂ -BF (×500);

Figure 4d is a scanning electron microscope image of SiO ₂ -BF (×3000);

Figure 4e is a scanning electron microscope image of SiO ₂ -BF (×30000);.

Detailed ways

The invention provides a graft modification method of basalt fiber, which includes the following steps:

1) Etch basalt fibers to obtain etched basalt fibers;

2) Mix the graft suspension and the silane coupling agent solution to obtain a modified solution;

The grafts in the graft suspension include nano-attapulgite or nano-silica;

3) Mix the etched basalt fiber obtained in step 1) with the modified solution obtained in step 2) and then perform a grafting reaction to obtain grafted basalt fiber.

In the present invention, basalt fibers are etched to obtain etched basalt fibers.

In the present invention, the reagent used for etching preferably includes sodium hydroxide solution or hydrochloric acid solution; the concentration of the sodium hydroxide solution is preferably 3 to 5 mol/L; the concentration of the hydrochloric acid solution is preferably 3 to 5 mol/L. L. In the present invention, the volume ratio of the mass of the basalt fiber to the reagent is preferably 1g:20ml; the etching conditions preferably include: soaking at a temperature of 60°C for 1 hour. In the present invention, the etching is to roughen the surface of the basalt fiber, increase its surface area, expose more hydroxyl groups, and provide more grafting sites. In the present invention, the basalt fiber is preferably pretreated before being etched; the pretreatment conditions preferably include: immersing the basalt fiber in an acetone solution for ultrasonic cleaning and drying; the quality of the acetone solution The percentage content is preferably 20%; the ultrasonic cleaning time is preferably 1 hour; the drying temperature is preferably 100°C. In the present invention, the basalt fiber is preferably chopped bundle basalt fiber. In the present invention, the surface of the basalt fiber is coated with a layer of sizing agent during the production process. On the one hand, the pretreatment uses acetone to remove the sizing agent on the fiber surface. On the other hand, the fibers exist in bundles, and ultrasound can disperse the fibers. effect.

In the present invention, the graft suspension is mixed with the silane coupling agent solution to obtain a modified solution; the graft in the graft suspension includes nano-attapulgite or nano-silica.

In the present invention, the preparation method of the graft suspension preferably includes: mixing the graft and the ethanol solution, stirring and ultrasonic to obtain the graft suspension; the mass of the graft is related to the ethanol solution. The volume ratio of is preferably 1g:100ml; the volume ratio of ethanol and water in the ethanol solution is preferably 9:1; the stirring time is preferably 30min, the stirring speed is preferably 400r/min; the ultrasonic The time is preferably 1 hour. In the present invention, the ethanol solution is beneficial to the dispersion of grafts.

In the present invention, when the graft is nano-attapulgite, the nano-attapulgite (ATP) is a fibrous or rod-shaped water-containing magnesium-rich aluminosilicate mineral, which has a large specific surface area and has Strong adsorption capacity, grafting ATP to the surface of BF, constructing ATP-grafted BF multi-scale reinforcement, is of great significance to control the structure and function of basalt fiber. Grafting ATP to basalt fiber can not only increase the roughness of the fiber surface It enhances the bonding strength with asphalt and can also absorb more asphalt. The mechanism is as follows: Silane coupling agent KH550 hydrolyzes when exposed to water, and the ethoxy group is replaced by a hydroxyl group to generate the hydrolysis product 3-aminopropylsilanetriol (silanol). The silanol reacts with the hydroxyl group on the surface of ATP and is grafted to ATP. On the other hand, silanol can also react with the hydroxyl groups on the surface of basalt fiber to complete another grafting process.

In the present invention, when the graft is nano-silica, the nano-silica is an inorganic chemical material with a size range of 1 to 100 nm, which can improve the aging resistance, strength and chemical resistance of other materials. ; At the same time, due to its small particle size, many micropores, large specific surface area, strong surface adsorption, large surface energy, good dispersion and other special properties. Grafting nano-SiO ₂ to the surface of basalt fiber to construct nano-SiO ₂ grafted to BF multi-scale reinforcement is of great significance to realize the structure and function control of basalt fiber; nano-SiO ₂ has good adsorption properties, and grafting nano-SiO ₂ to BF multi-scale reinforcement is of great significance. On the one hand, grafting the fiber to the fiber can increase the roughness of the fiber surface and enhance the bonding strength with asphalt; on the other hand, adding the grafted fiber to the asphalt can comprehensively improve the performance of the composite material, including increasing strength and elongation as well as improving wear resistance. . The mechanism is as follows: the silane coupling agent KH550 hydrolyzes when it encounters water, and the ethoxy group is replaced by a hydroxyl group to generate the hydrolysis product 3-aminopropylsilanetriol (silanol). The silanol reacts with the hydroxyl group on the surface of nano-SiO ₂ and is grafted. to the surface of nano-SiO ₂ ; on the other hand, silanol can also react with the hydroxyl groups on the surface of basalt fiber to complete another grafting process.

In the present invention, the preparation method of the silane coupling agent solution preferably includes: mixing and stirring the silane coupling agent and the ethanol solution to obtain a silane coupling agent solution. In the present invention, the volume ratio of the silane coupling agent to the ethanol solution is preferably 20:500; the volume ratio of ethanol and water in the ethanol solution is preferably 9:1; the stirring conditions preferably include: the temperature is 60℃, time is 30min, rotation speed is 400r/min. In the present invention, the silane coupling agent preferably includes silane coupling agent KH550. In the present invention, the volume ratio of the graft suspension and the silane coupling agent solution in step 2) is preferably 100:520; the mixing conditions preferably include: time is 1 h, and rotation speed is 120 r/min.

In the present invention, the obtained etched basalt fiber is mixed with the obtained modified solution and then a grafting reaction is performed to obtain grafted basalt fiber.

In the present invention, the conditions for the grafting reaction preferably include: temperature of 25-30°C, time of 3 hours, and rotation speed of 120 r/min. In the present invention, the volume ratio of the mass of the etched basalt fiber to the obtained modified solution is preferably 10g:620ml.

In order to further illustrate the present invention, the present invention is described in detail below with reference to the examples, but they should not be understood as limiting the protection scope of the present invention.

Example 1

The steps of the grafting method for preparing basalt fiber with high oil absorption rate are as follows:

(1) Pretreatment BF: Weigh an appropriate amount of BF and immerse it in 600ml of acetone solution with a volume percentage of 20%, put it into an ultrasonic cleaner for cleaning for 1 hour, take it out and clean it repeatedly with deionized water, and put it into a 100°C oven Medium drying;

(2) Etching: Prepare a 3mol/L HCl solution, place the pretreated BF into the HCl solution, stir thoroughly, and soak for 1 hour at 60°C. After the etching is completed, rinse the BF with deionized water until it reaches the surface. It is neutral; 1g basalt fiber is mixed with 20ml HCl solution;

(3) Preparation of ATP suspension: Add 1g ATP to 100 ml of ethanol-deionized water mixed solution, stir magnetically for 30 minutes, and sonicate for 1 hour to disperse. The volume ratio of ethanol to deionized water in the mixed solution is 9:1;

(4) Prepare the modifier solution: add 20 ml of silane coupling agent KH550 to 500 ml of ethanol solution, stir for 1 hour, and accelerate hydrolysis until the solution is transparent and free of precipitation; pour the ATP suspension prepared in step (3) into the hydrolyzed silane In the coupling agent solution, continue stirring for 1 hour to obtain a modifier solution;

(5) ATP grafted BF: Put 10g of pretreated BF into 620ml of modifier solution for grafting, stir and react at room temperature for 3 hours to obtain ATP-BF. Take out the ATP-BF and put it into a centrifuge for washing for 10 minutes at a speed of 5000r/min. After washing, take it out and place it in an 80°C oven for 2 hours before taking it out.

Test results and analysis:

1 Electron microscope scanning test

It can be seen from Figure 3a to Figure 3f that after ATP grafting treatment, the surface roughness of the basalt fiber is greatly improved. After washing, the surface of the ATP-grafted basalt fiber still has a large amount of ATP attached. In Figure 3c and Figure 3d, After the fibers were dispersed, good modification effects were obtained. It can be clearly seen in Figure 3e and Figure 3f that the unique fiber structure of ATP completely wraps the basalt fiber, which further verifies the success of ATP grafting.

2 Asphalt suction and holding test

Test method: Weigh 5.0g of the original BF and ATP-BF respectively, put them into a container containing 80g of asphalt, stir, mix evenly and pour into the sieve, place a container under the sieve to contain the leaked asphalt, and then put Put them together into an oven at 165°C and keep them warm until the weight on the sieve does not change (the test was carried out in three sets of parallel tests and the average value was taken). The calculation formula for the asphalt adsorption rate η of the basalt fiber is as shown in formula (1), and the test results are as shown in the table shown.

In the formula: m ₀ , m ₁ , m ₂ ——the mass of basalt fiber, the overall mass of the sieve at constant weight, and the mass of the sieve.

Table 1 Test results of original BF and ATP-BF asphalt adsorption capacity

fiber type m ₀ (g) m ₂ (g) m ₁ (g) Oil absorption rate (%) As is BF 5.0 39.8 64.3 390 ATP-BF 5.0 39.8 77.9 662

As can be seen from Table 1, the ability of ATP-grafted basalt fiber to absorb asphalt is 69.7% higher than that of the original basalt fiber, indicating that ATP-grafted basalt fiber has good compatibility and wettability with asphalt and can effectively improve mixing The amount of asphalt in the material enhances the performance of the asphalt pavement.

Example 2

The steps of the grafting method for preparing basalt fiber with high interface strength with asphalt are as follows:

(1) Pretreatment BF: Weigh an appropriate amount of BF and immerse it in 600ml of acetone solution with a volume percentage of 20%, put it into an ultrasonic cleaner for cleaning for 1 hour, take it out and clean it repeatedly with deionized water, and put it into a 100°C oven Medium drying;

(2) Etching: Prepare a 3mol/L HCl solution, place the pretreated BF into the HCl solution, stir thoroughly, and soak for 1 hour at 60°C. After the etching is completed, rinse the BF with deionized water until it reaches the surface. It is neutral; 1g basalt fiber is mixed with 20ml HCl solution;

(3) Preparation of nano-SiO ₂ suspension: Add 1 g of nano-SiO ₂ to 100 ml of ethanol-deionized water mixed solution, magnetically stir for 30 minutes, and ultrasonic for 1 hour to disperse. The volume ratio of ethanol to deionized water in the mixed solution is 9:1;

(4) Prepare the modifier solution: Add 20 ml of silane coupling agent KH550 to 500 ml of ethanol solution, stir for 1 hour, and accelerate hydrolysis until the solution is transparent and free of precipitation. Pour the nano-SiO ₂ suspension into the hydrolyzed silane coupling agent solution, and continue stirring for 1 hour to obtain a modifier solution;

(5) Nano-SiO ₂ grafted BF: Put 10g of pretreated BF into 620 ml of modifier solution for grafting, stir and react at room temperature for 3 hours, and obtain SiO ₂ -BF. Take out the SiO ₂ -BF and put it into a centrifuge for washing for 10 minutes at a speed of 5000r/min. After washing, take it out and place it in an 80°C oven for 2 hours before taking it out.

Although the above embodiments describe the present invention in detail, they are only part of the embodiments of the present invention, not all embodiments. People can also obtain other embodiments based on this embodiment without any inventive step. These embodiments All belong to the protection scope of the present invention.

Test results and analysis:

1 Electron microscope scanning test

It can be seen from Figure 4a to Figure 4e that after nano-SiO ₂ grafting treatment, the surface roughness of the basalt fiber is greatly improved. After washing, the surface of the nano-SiO ₂ grafted basalt fiber still has a large amount of ATP attached to it. In Figure 4c and Figure In 4d, after the fibers were dispersed, good modification effects were obtained. Figure 4e can clearly see that nano-SiO ₂ completely wrapped the basalt fiber, which further verified that the nano-SiO ₂ grafting was successful.

2 Asphalt suction and holding test

Test method: Weigh 5.0g of the original BF and SiO ₂ -BF respectively, and put them into a container containing 80g of asphalt and stir them. After mixing evenly, pour them into the sieve, place a container under the sieve to contain the leaked asphalt, and then Put them together into an oven at 165°C and keep them warm until the weight on the sieve does not change (the test is conducted in 3 sets of parallel tests and the average value is taken). The calculation formula for the asphalt adsorption rate η of the basalt fiber is as shown in formula (1), and the test results are as follows shown in the table.

In the formula: m ₀ , m ₁ , m ₂ ——the mass of basalt fiber, the overall mass of the sieve at constant weight, and the mass of the sieve.

Table 2 Test results of asphalt adsorption capacity of original BF and SiO ₂ -BF

fiber type m ₀ (g) m ₂ (g) m ₁ (g) Oil absorption rate (%) As is BF 5.0 39.8 64.3 390 _SiO2 -BF 5.0 39.8 72.5 554

It can be seen from Table 2 that the ability of SiO ₂ grafted basalt fiber to absorb asphalt is 42.1% higher than that of the original basalt fiber, indicating that nano-SiO ₂ grafted basalt fiber has better compatibility and wettability with asphalt, and can Effectively increase the amount of asphalt in the mixture and enhance the performance of asphalt pavement.

Claims (10)

1. The grafting modification method of basalt fiber is characterized by comprising the following steps:

1) Etching the basalt fiber to obtain etched basalt fiber;

2) Mixing the graft suspension with a silane coupling agent solution to obtain a modified solution;

the grafts in the graft suspension comprise nano attapulgite or nano silicon dioxide;

3) And (2) mixing the etched basalt fiber obtained in the step (1) with the modified solution obtained in the step (2) and then carrying out grafting reaction to obtain grafted basalt fiber.

2. The method according to claim 1, wherein the agent used in the etching in step 1) comprises sodium hydroxide solution or hydrochloric acid solution;

the concentration of the sodium hydroxide solution is 3-5 mol/L;

the concentration of the hydrochloric acid solution is 3-5 mol/L.

3. The graft modification process according to claim 1 or 2, characterized in that the ratio of mass of basalt fiber to volume of reagent is 1g:20ml;

the etching conditions include: soaking at 60deg.C for 1 hr.

4. The graft modification process according to claim 1, wherein the preparation process of the graft suspension of step 2) comprises: mixing the graft with ethanol solution, stirring and ultrasonic treatment to obtain a graft suspension;

the volume ratio of the mass of the graft to the ethanol solution is 1g to 100ml;

the volume ratio of ethanol to water in the ethanol solution is 9:1;

the stirring time is 30min, and the ultrasonic time is 1h.

5. The graft modification method according to claim 1, wherein the basalt fiber of step 1) is subjected to pretreatment and then etched;

the pretreatment conditions include: immersing the basalt fiber into an acetone solution for ultrasonic cleaning and drying;

the mass percentage of the acetone solution is 20%;

the ultrasonic cleaning time is 1h;

the temperature of the drying was 100 ℃.

6. The graft modification process according to claim 1, wherein the preparation method of the silane coupling agent solution of step 2) comprises: and mixing and stirring the silane coupling agent and the ethanol solution to obtain a silane coupling agent solution.

The volume ratio of ethanol to water in the ethanol solution is 9:1.

7. The graft modification process of claim 6 wherein the volume ratio of the silane coupling agent to the ethanol solution is 20:500;

the stirring conditions include: the temperature is 25 ℃, the time is 1h, and the rotating speed is 400r/min.

8. The graft modification method according to claim 6 or 7, wherein the silane coupling agent comprises a KH550 type silane coupling agent.

9. The graft modification process according to claim 1, wherein the volume ratio of the graft suspension to the silane coupling agent solution in step 2) is 100:520;

the mixing conditions include: the time is 1h, and the rotating speed is 120r/min.

10. The graft modification process according to claim 1, wherein the grafting reaction conditions of step 3) comprise: the temperature is 25-30 ℃, the time is 3h, and the rotating speed is 120r/min.