CN117844127A - A preparation method of high-filled basalt fiber/ethylene propylene diene monomer rubber composite material - Google Patents

Abstract

The invention discloses a preparation method of a high-filling basalt fiber/ethylene propylene diene monomer composite material, which comprises the following steps: pretreating basalt fiber, performing surface treatment on Basalt Fiber (BF), and preparing a high-filling basalt fiber/ethylene propylene diene monomer composite material; placing BF in an acetone solution, performing ultrasonic treatment in an ultrasonic dispersing instrument for 1h to remove impurities on the surface of BF, performing suction filtration by deionized water, and then placing in an oven for drying; then placing BF into 1mol/L sodium hydroxide solution, magnetically stirring for 2h, and after treatment, repeatedly filtering by deionized water, and placing into a baking oven for baking to obtain pretreated BF; immersing BF in titanate solution with concentration of 5% -10%, magnetically stirring for 2h, water-bathing at 60 ℃, suction-filtering, and drying in an oven to obtain modified BF. The invention increases the toughness of BF skeleton material and rubber compound, effectively improves the dispersibility of BF in a rubber matrix, improves the adhesion between BF and a rubber base layer, and improves the comprehensive performance of the composite material.

Description

A preparation method of high-filled basalt fiber/ethylene propylene diene monomer rubber composite material

Technical Field

The invention relates to the field of rubber product preparation, in particular to a method for highly filled short fiber reinforced EPDM rubber.

Background technique

In recent years, with the critical period of China's economic transformation from high-speed growth to high-quality growth, the rapid development of the rubber tire industry, my country has begun to have higher and higher requirements for the quality of tire products, and the tire industry in the automotive industry should also transform from pursuing output to pursuing quality. Adding basalt short fibers to tires can effectively enhance the strength, wear resistance, stability, and anti-breakage performance of rubber, but basalt fibers also have the problem of poor compatibility and dispersibility with the rubber matrix. Therefore, it is extremely important to surface treat basalt fibers to enhance their compatibility and dispersibility with the rubber matrix.

For rubber materials, the more fibers are added, the mechanical properties of the rubber composite material will first increase and then decrease. In order to reduce the production cost of rubber composite materials, increase the content of basalt fibers in rubber composite materials and increase the mechanical properties of rubber composite materials, it is necessary to conduct a comprehensive and systematic analysis of various aspects of the performance of high-filled basalt fiber/rubber composite materials in order to find the optimal fiber content of high-filled basalt fiber/rubber composite materials.

By utilizing the affinity functional groups contained in the coupling agent molecules, these functional groups can chemically react with the active sites on the surface of the basalt fiber to form bonds. These bonds can enhance the adhesion between the fiber and the resin and reduce the risk of interface separation in the composite material. This helps to improve the strength and durability of the material.

Chinese patent CN201910980616.2 discloses a basalt fiber rubber composite material and a preparation method thereof, including raw basalt fiber for preparing modified basalt fiber dipped skeleton and raw rubber particles, plasticizer, glass fiber, reinforcing agent, accelerator, wear-resistant agent, sulfur and antioxidant for preparing mixed rubber, and also includes the following preparation steps: step one: preparing basalt fiber skeleton; step two: pretreatment of basalt fiber skeleton; step three: pretreatment of basalt fiber skeleton modification; step four: one-bath dip; step five: preparing mixed rubber; step six: two-bath dip; step seven: flattening; step eight: vulcanization. The present invention aims to improve the problems of poor wear resistance of basalt fiber rubber composite materials in the prior art and poor bonding performance between basalt fiber skeleton and rubber base layer. The present invention has the advantages of improving the wear resistance of basalt fiber rubber composite materials and improving the bonding performance between basalt fiber skeleton and rubber base layer. However, it does not disclose the technical solution of pretreating basalt staple fibers using titanate, titanate and silane coupling agent to achieve better pretreatment effect.

Summary of the invention

In view of the above problems, the purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing a highly filled basalt fiber/ethylene propylene diene monomer rubber composite material, thereby improving the dispersibility of basalt fiber in the rubber matrix and further improving the comprehensive performance of the composite material.

In order to achieve the above-mentioned purpose, the present invention relates to a method for preparing a high-filled basalt fiber/ethylene propylene diene monomer rubber composite material, the steps of which include: pretreatment of basalt fiber, surface treatment of basalt fiber, and preparation of a high-filled basalt fiber/ethylene propylene diene monomer rubber composite material;

Preferably, (1) basalt fiber pretreatment: basalt fiber is placed in an acetone solution, ultrasonically treated in an ultrasonic disperser for 1 hour to remove impurities on the surface of the basalt fiber, and then filtered with deionized water and placed in an oven for drying. Then, the basalt fiber is placed in a sodium hydroxide solution (1 mol/L) and magnetically stirred for 2 hours. After the treatment is completed, it is repeatedly filtered with deionized water and placed in an oven for drying to obtain pretreated basalt fiber.

(2) Surface treatment of basalt fiber: The basalt fiber was immersed in a 5%-10% titanate solution, magnetically stirred for 2 hours, and placed in a water bath at 60°C. After filtration, the fiber was placed in an oven for drying to obtain modified basalt fiber.

(3) Preparation of highly filled basalt fiber/EPDM rubber composites:

Prepare the materials according to the following mass proportions: EPDM, 100; carbon black N330, 30; zinc oxide ZnO, 5; stearic acid SAD, 1; antioxidant 4020, 2; accelerator RD, 1.5; accelerator M, 0.5; TMTD, 1; sulfur S, 1.5; 3mm modified BF, 10/15/20.

Preferably, the EPDM rubber is weighed and plasticized on an open mixer to increase its plasticity and improve its fluidity. Secondly, the plasticized EPDM rubber is mixed with the formula material and basalt fiber in an internal mixer.

Preferably, sulfur is added on an open mill for refining, orientation, and sheeting to obtain a mixed rubber with basalt oriented in the rolling direction, and then the mixed rubber is allowed to stand for 24 hours.

Preferably, finally, a pin extruder and a barrier dam expansion die are used to achieve radial orientation of the basalt fiber/EPDM rubber composite material: the mixed rubber is placed in the extruder, the extruder temperature is set to 80° C., and the speed is variable.

Preferably, the radial orientation of the basalt fiber on the EPDM rubber is finally achieved through a barrier expansion extruder head at the end of the extruder. The obtained rubber compound is placed for a period of time and then vulcanized.

Preferably, the radially oriented rubber mixture is vulcanized using a flat vulcanizer to obtain a basalt fiber/EPDM rubber composite material, and then left at room temperature for 24 hours to prepare a sample.

Preferably, the pretreated basalt fiber of the present invention has a drying temperature of 60° C. and a drying time of 12 hours.

Furthermore, the modified basalt fiber of the present invention has a drying temperature of 60° C. and a drying time of 24 hours.

Furthermore, the modified basalt fiber of the present invention is treated by mixing a titanate solution with a concentration of 5% to 10% and a titanate solution with a silane coupling agent solution.

Furthermore, in the method for preparing the basalt fiber/EPDM rubber composite material of the present invention, the roller spacing of the mixing mill is adjusted to 0.5 mm, and the EPDM rubber is passed through the mixing mill 15-20 times to complete the plastication.

Furthermore, in the preparation method of the basalt fiber/EPDM rubber composite material of the present invention, the cooling water temperature of the internal mixer is 45°C, the rotor speed is 40rpm, the filling factor is 0.6, the upper push bolt pressure is 0.6MPa, the mixing temperature is 60°C, and the mixing time is 5min.

Furthermore, in the method for preparing the basalt fiber/EPDM rubber composite material of the present invention, sulfur is added to the mixing mill at a minimum roller distance, and the sheet is unloaded after the roller distance of the mixing mill is increased.

Furthermore, in the method for preparing the basalt fiber/EPDM rubber composite material of the present invention, the vulcanization conditions are set as a vulcanization temperature of 150° C., a vulcanization time of t ₉₀ ×1.3, and a vulcanization pressure of 10 MPa.

The technical solution of the present invention has at least the following advantages and beneficial effects:

(1) The present invention first pre-treats the basalt fiber to remove impurities such as short flocs and dust adhering to the surface of the basalt fiber, and utilizes the characteristics of the coupling agent molecules containing both active functional groups such as methyl, vinyl and epoxy groups that have affinity with high molecular polymers and methoxy and oxy groups that can be hydrolyzed to treat the surface of the basalt fiber, thereby enhancing its compatibility with the rubber matrix. The pre-treated basalt fiber is modified, and active groups are introduced on the surface of the basalt fiber. The modified basalt fiber is then placed in the rubber mix, and a barrier expansion die is used to achieve radial orientation of the basalt fiber/EPDM rubber composite material, and finally vulcanization treatment is performed.

(2) The surface treated basalt fiber increases the toughness of the basalt fiber skeleton material and the rubber compound. The comprehensive performance of the basalt fiber/EPDM rubber composite material obtained after vulcanization is improved to a certain extent, and the adhesion between the basalt fiber and the rubber base obtained after vulcanization of the rubber compound is significantly improved. The optimal proportion of basalt fiber and the optimal screw speed are determined.

(3) The present invention overcomes the shortcomings of the prior art, provides a method for preparing a highly filled basalt fiber/ethylene propylene diene monomer rubber composite material, and improves the comprehensive performance of the composite material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a diagram showing the chemical reaction process of treating basalt fiber with titanate according to the present invention;

FIG2 is a diagram showing the chemical reaction process of treating basalt fiber with a mixed solution of titanate and silane coupling agent according to the present invention;

FIG3 is a SEM image of BF modified by mixed solutions of titanate and silane coupling agent at different concentrations of the present invention; FIG3(a) is BF treated with 3% concentration; FIG3(b) is BF treated with 6% concentration; FIG3(c) is BF treated with 10% concentration;

FIG4 is a SEM image of a BF/EPDM composite material with different addition amounts of BF modified by a titanate solution of the present invention; wherein FIG4 (a) BF is 10phr; (b) BF is 15phr; (c) BF is 15phr; (d) BF is 20phr;

Detailed ways

The present invention is described below in conjunction with the accompanying drawings and specific embodiments.

To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition and explanation in the subsequent drawings.

As shown in Figure 1-4,

In order to more clearly illustrate the present invention or make the advantages of the present technical solution more clear, the preparation method of the basalt fiber/ethylene propylene diene monomer rubber composite material of the present invention is described in detail below through examples.

Embodiment 1:

The process of the method for preparing the high-filled basalt fiber/EPDM rubber composite material involved in this embodiment mainly includes three steps: basalt fiber pretreatment, basalt fiber surface treatment, and preparation of the high-filled basalt fiber/EPDM rubber composite material:

(1) Basalt fiber pretreatment: The basalt fiber was placed in an acetone solution and ultrasonically treated in an ultrasonic disperser for 1 hour to remove impurities on the surface of the basalt fiber. After being filtered with deionized water, the fiber was placed in an oven for drying at 60°C for 12 hours. The basalt fiber was then placed in a sodium hydroxide solution (1 mol/L) and magnetically stirred for 2 hours. After the treatment, the fiber was filtered with deionized water again and placed in an oven for drying at 60°C for 12 hours to obtain pretreated basalt fiber.

(2) Surface treatment of basalt fiber: immerse the basalt fiber in 5%-10% titanate solution, stir it with magnetic force for 2 hours, and place it in a water bath at 55°C. Then, after filtration, put it in an oven for drying at 60°C for 24 hours. Modified basalt fiber is obtained.

(3) Preparation of basalt fiber/EPDM rubber composite materials:

Prepare the materials according to the following mass parts: EPDM, 100; carbon black N330, 30; zinc oxide ZnO, 5; stearic acid SAD, 1; microcrystalline wax, 5; antioxidant 4020, 2; accelerator RD, 1.5; accelerator M, 0.5; TMTD, 1; sulfur S, 1.5; 3mm modified BF, 10.

Weigh the EPDM rubber and plasticize it on an open mixer to improve its plasticity and fluidity. Secondly, mix the plasticized EPDM rubber with the formula materials and basalt fiber in an internal mixer. Finally, add sulfur on the open mixer to mix, orient, and unroll. The mixed rubber with basalt oriented in the rolling direction is obtained, and then it is left to stand for 24 hours.

The radial orientation of basalt fiber/EPDM composite material was achieved by using a pin extruder and a barrier expansion die: the mixed rubber was put into the extruder, the extruder temperature was set to 80°C, and the speed was 5r/min. Finally, the radial orientation of basalt fiber in EPDM was achieved by using a barrier expansion extruder at the end of the extruder. The obtained rubber was vulcanized after being left for a period of time.

The obtained rubber compound was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization time of t ₉₀ ×1.3, and a vulcanization pressure of 10 MPa. Thus, a basalt fiber/EPDM rubber composite material was obtained. The sample was then prepared by placing it at room temperature for 24 hours.

Embodiment 2:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 10 parts of 3mm modified BF and a screw speed of 10r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 3:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 10 parts of 3mm modified BF and a screw speed of 15r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 4:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 10 parts of 3mm modified BF and a screw speed of 20r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 5:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 15 parts of 3mm modified BF and a screw speed of 5r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 6:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 15 parts of 3mm modified BF and a screw speed of 10r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 7:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 15 parts of 3mm modified BF and a screw speed of 15r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 8:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 15 parts of 3mm modified BF and a screw speed of 20r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 9:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 20 parts of 3mm modified BF and a screw speed of 5r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 10:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 20 parts of 3mm modified BF and a screw speed of 10r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 11:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 20 parts of 3mm modified BF and a screw speed of 15r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 12:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 20 parts of 3mm modified BF and a screw speed of 20r/min. The specific process of Example 1 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 13:

Step 1: Place BF in an acetone solution and stir it magnetically at 70°C for 2 hours to remove impurities on the surface of BF. Then, after suction filtration, place it in an oven (set to 80°C) and dry it for 12 hours. Then, place BF in a glacial acetic acid solution (1 mol/L) and stir it magnetically for 2 hours. After the treatment is completed, place it in an oven (set to 80°C) and dry it for 12 hours after repeated suction filtration to obtain pretreated BF.

The basalt fiber was immersed in a 5%-10% titanate solution, magnetically stirred for 2 hours, and placed in a water bath at 55°C. After filtration, the fiber was placed in an oven for drying at 60°C for 24 hours to obtain modified basalt fiber.

Step 2: Immerse the basalt fiber in a mixed solution of titanate and silane coupling agent, put the BF into an ultrasonic disperser for ultrasonic treatment for 2 hours, then filter it and put it into an oven (set at 80°C) for drying for 24 hours for use.

Step 3: Put 100 parts by mass of EPDM rubber, 30 parts by mass of carbon black N330, 10 parts by mass of 3mm modified BF, 5 parts by mass of stearic acid, 1 part by mass of zinc oxide, 5 parts by mass of microcrystalline wax, 1.5 parts by mass of accelerator RD (anti-aging agent) and 2 parts by mass of 4020 (anti-aging agent) into an internal mixer, and mix them at a temperature of 70°C and a speed of 45r/min to obtain a rubber compound. Mix 1.5 parts by mass of S (sulfur), 0.5 parts by mass of M and 1.5 parts by mass of TMTD (vulcanization accelerator) with the rubber compound on an open mill, and pass it thinly, wherein the rolling and triangle wrapping are performed four times each to obtain a rubber compound, and then let it stand for 24 hours.

The radial orientation of basalt fiber/EPDM composite material was achieved by using a pin extruder and a barrier expansion die: the mixed rubber was put into the extruder, the extruder temperature was set to 80°C, and the speed was 10r/min. Finally, the radial orientation of basalt fiber in EPDM was achieved by using a barrier expansion extruder at the end of the extruder. The obtained rubber was placed for a period of time and then vulcanized.

The obtained rubber compound was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization time of t ₉₀ ×1.3, and a vulcanization pressure of 10 MPa. Thus, a basalt fiber/EPDM rubber composite material was obtained. The sample was then prepared by placing it at room temperature for 24 hours.

Embodiment 14:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 15 parts of 3mm modified BF and a screw speed of 10r/min. The specific process of Example 13 is used to prepare the basalt fiber/EPDM rubber composite material.

Embodiment 15:

The method for preparing the basalt fiber/EPDM rubber composite material involved in this example uses 20 parts of 3mm modified BF and a screw speed of 10r/min. The specific process of Example 13 is used to prepare the basalt fiber/EPDM rubber composite material.

Comparative Example 1:

The control group of this experiment was not added with basalt short fibers. The physical and mechanical properties of the basalt fiber/EPDM rubber composite materials in comparative example 1 and embodiments 1-15 of the present invention were tested respectively. The test results are shown in Table 1 below:

Compared with EPDM without BF, when BF is added to the EPDM matrix, the Shore A hardness of the composite material is significantly improved. This is because when BF is added to the EPDM matrix as a filler, the hardness of BF is greater than that of the EPDM matrix, so its hardness is greatly improved. When BF is added to EPDM, the DIN wear of the BF/EPDM composite material decreases. With the increase of the number of BF additions, the DIN wear shows a trend of first decreasing and then increasing. When the number of BF parts is 15, the DIN wear of the EPDM composite material without BF is reduced by 25.2%. This is because when the number of BF additions is small, BF is less agglomerated in the EPDM matrix, which makes it easier for the fiber and the rubber matrix to form a bonding interface, and fewer stress concentration points appear. When the composite material is subjected to friction, the interface formed by BF and EPDM can limit the slippage of the rubber molecular chain; when the composite material is subjected to friction and the interface phase is destroyed, the exposed BF of the composite material can protect the composite material from damage. However, as the amount of BF added increases, a large number of fiber agglomeration will occur in the rubber matrix, resulting in the formation of multiple stress concentration points, thereby increasing the DIN wear value of the BF/EPDM composite material.

When BF is added as a reinforcing material to the EPDM rubber matrix, the tensile strength, tear strength and 300% modulus of the composite material are all reduced. This is because too many fibers are added, and BF is difficult to disperse in the EPDM matrix and is more likely to agglomerate, making it difficult for BF to be completely compatible with the EPDM matrix, resulting in a large number of stress concentration points formed in the rubber matrix, and the adhesion with the rubber matrix becomes poor. When the BF/EPDM composite material is subjected to tension, BF is more likely to be pulled out of the EPDM matrix.

When the screw speed is 15r/min, the physical and mechanical properties of the composite material are better, and the wear is reduced by 17.4% compared with 20r/min. The analysis shows that the pressure of the rubber increases when passing through the die, the shear and tensile effect of the short fibers in the flow channel of the extruder head is enhanced, the radial orientation of the short fibers increases, and the density of the rubber increases.

As can be seen from Table 1, the physical and mechanical properties of the BF/EPDM composite material obtained by modifying BF with a titanate solution are better than those obtained by modifying BF with a mixed solution of titanate and silane coupling agent.

Table 1 Physical and mechanical properties of BF/EPDM composites under different preparation conditions

As a preferred embodiment of the present invention, FIG1 shows the chemical reaction process of basalt fiber treated with titanate:

In this process, the titanate Ti(OR) ₄ undergoes hydrolysis to generate a hydroxyl-containing compound Ti(OR) ₃ (OH), which then reacts with the hydroxyl functional group (Si-OH) on the surface of the basalt fiber to form a hydroxyl-containing compound Ti(OR) ₃ (O-Si), which is a surfactant that can strengthen the bond between the basalt fiber and the titanate coupling agent, thereby strengthening the bond between the basalt fiber and the rubber material.

Titanate coupling agents also act as dispersants, helping to evenly disperse the basalt fibers in the rubber matrix. This helps prevent fiber agglomeration and improves the uniformity of the composite, thereby improving performance.

Titanate coupling agent can reduce the energy of the interface by introducing a thinner layer of affinity compound at the interface, thereby improving the properties of the interface, helping to reduce the loss of stress transfer and improving the strength and stiffness of the composite material.

Figure 2 shows the chemical reaction process of basalt fiber treated with a mixed solution of titanate and silane coupling agent:

As a preferred embodiment of the present invention, titanate can be combined with a silane coupling agent for surface treatment of basalt fiber. Silane coupling agent contains silicon (Si) functional groups, which can react with hydroxyl (-OH) groups on the surface of basalt fiber to form chemical bonds, thereby improving the bonding between the fiber and the matrix. A common silane coupling agent is 3-aminopropyltrimethoxysilane, with the chemical formula: NH ₂ -(CH ₂ ) ₃ -Si(OMe) ₃ .

The reaction between NH ₂ -(CH ₂ ) ₃ -Si(OMe) ₃ (3-aminopropyltrimethoxysilane) and Ti(OR) ₄ (titanate coupling agent) can lead to an esterification reaction between them, generate an ester bond, and release methanol (CH ₃ OH) as a reaction product. This reaction forms an ester bond between the silicon functional group in the silane coupling agent and the functional group (ethoxy) in the titanate coupling agent. This esterification reaction helps to introduce the silane coupling agent into the titanate coupling agent to form a more complex molecular structure, which is used to improve the surface properties of the material or as a surface treatment agent.

The reaction between _NH2- ( _CH2 ) ₃ -Si(OMe) ₃ and Si-OH (hydroxyl groups on the surface of basalt fiber) will cause the silane coupling agent to react chemically with the surface of basalt fiber to form a silicon-oxygen-silicon (Si-O-Si) bond. The silane coupling agent is introduced to the surface of basalt fiber through the formation of silicon-oxygen-silicon bonds, which improves the bonding between the fiber and the silane coupling agent. This surface treatment helps to improve the bonding strength between basalt fiber and rubber materials, thereby improving the performance of the composite material.

As shown in Figure 3, the mixed solution of titanate and silane coupling agent successfully modified BF, and with the increase of the concentration of the mixed solution of titanate and silane coupling agent, the modification effect of the fiber became better and better. Among them, the BF treated with the mixed solution of 6% titanate and silane coupling agent had the best modification effect. The titanate and silane coupling agent molecules were evenly coated on the surface of BF, so that BF and EPDM matrix had good adhesion, thereby improving the comprehensive performance of BF/EPDM composite materials.

Figure 4 is a SEM image of BF with different addition ratios in the EPDM matrix. It can be seen that after the BF/EPDM composite material is radially oriented by the barrier expansion head, the BF is arranged uniformly in the EPDM matrix, so that the fiber plays the role of skeleton filling in the rubber. At the same time, it can be seen that there is obvious glue hanging on the fiber surface at the brittle fracture, and there are no obvious holes in the fiber in the rubber matrix, and the interface connection is tighter, indicating that the compatibility between BF and the EPDM matrix after surface treatment with 10% titanate coupling agent solution is improved. It can be seen from the figure that with the increase in the number of BF additions, the density of BF in the rubber matrix increases. When the fiber number is 15, BF has good dispersion in the EPDM matrix and fewer pores and gaps, indicating that BF is not easy to be pulled out.

The above embodiments are only used to illustrate and not to limit the technical solutions of the present invention. Any modification or partial replacement that does not deviate from the spirit of the present invention should be included in the scope of the claims of the present invention.

Claims (5)

1. A method for preparing a highly filled basalt fiber/ethylene propylene diene monomer rubber composite material, characterized in that: The steps include: pretreatment of basalt fiber, surface treatment of basalt fiber, preparation of high-filled basalt fiber/EPDM rubber composite material; Among them, the basalt fiber pretreatment: the basalt fiber is placed in an acetone solution, ultrasonically treated in an ultrasonic disperser for 1 hour to remove impurities on the surface of the basalt fiber, and then filtered with deionized water and placed in an oven for drying; the basalt fiber is then placed in a 1mol/L sodium hydroxide solution and magnetically stirred for 2 hours. After the treatment is completed, the deionized water is repeatedly filtered and placed in an oven for drying to obtain the pretreated basalt fiber; Surface treatment of basalt fiber: immerse the basalt fiber in a 5%-10% titanate solution, stir it with a magnetic force for 2 hours, and place it in a water bath at 60°C. Then, filter it and dry it in an oven to obtain modified basalt fiber. Preparation of highly filled basalt fiber/EPDM rubber composites: Prepare the materials according to the following mass parts: EPDM, 100; carbon black N330, 30; zinc oxide ZnO, 5; stearic acid SAD, 1; antioxidant 4020, 2; accelerator RD, 1.5; accelerator M, 0.5; TMTD, 1; sulfur S, 1.5; 3mm modified BF, 10 parts. 2. The method for preparing a highly filled basalt fiber/EPDM rubber composite material according to claim 1, characterized in that: The steps of preparing the highly filled basalt fiber/EPDM rubber composite material include: weighing the EPDM rubber and plasticizing it on an open mill to increase its plasticity and improve its fluidity; Secondly, the plasticized EPDM rubber is mixed with the formula materials and basalt fiber in an internal mixer; Finally, sulfur is added on the open mill for refining, orientation, and sheeting to obtain a mixed rubber with basalt oriented in the rolling direction, and then allowed to stand for 24 hours; Finally, the radial orientation of the basalt fiber/EPDM composite was achieved by using a pin extruder and a barrier dam expansion die: the rubber mix was placed in the extruder, and the extruder temperature was set to 80 °C; Finally, the radial orientation of the basalt fiber in the EPDM rubber is achieved through a barrier expansion extruder head at the end of the extruder, and the obtained rubber compound is vulcanized after being left for a period of time; The radially oriented mixed rubber is vulcanized by a flat vulcanizer to obtain a basalt fiber/ethylene propylene diene monomer rubber composite material. 3. The method for preparing a highly filled basalt fiber/EPDM rubber composite material according to claim 2, characterized in that: The basalt fiber was pretreated at a drying temperature of 60°C and a drying time of 12 hours. 4. The method for preparing a highly filled basalt fiber/EPDM rubber composite material according to claim 3, characterized in that: Modified basalt fiber, drying temperature is 60℃, drying time is 24 hours; Modified basalt fiber is treated with 5%-10% titanate solution. 5. The method for preparing a highly filled basalt fiber/EPDM rubber composite material according to claim 2, characterized in that: The roller spacing of the open mill is adjusted to 0.5 mm, and the EPDM rubber is passed through 15-20 times to complete plastication; The internal mixer has a cooling water temperature of 45°C, a rotor speed of 40 rpm, a filling factor of 0.6, an upper push bolt pressure of 0.6 MPa, a mixing temperature of 60°C, and a mixing time of 5 min; Sulfur is added to the mixing mill at the minimum roller distance, and the sheet is unloaded after the roller distance of the mixing mill is increased; The vulcanization conditions are set as follows: the vulcanization temperature is 150° C., the vulcanization time is t ₉₀ ×1.3, and the vulcanization pressure is 10 MPa.