A magnetorheological elastomer with high mechanical strength and a preparation method thereof

Abstract

The present invention relates to the technical field of intelligent materials, and specifically to a magnetorheological elastomer with high mechanical strength and a preparation method thereof. First, in this application, carbonyl iron powder and iron oxide hydroxide are used as raw materials, and they are polymerized with (3-aminopropyl)triethoxysilane to prepare magnetic groups. These magnetic groups can replace traditional magnetic particles to enhance the interfacial bonding force between magnetic particles and the rubber matrix in the magnetorheological elastomer. Moreover, in the preparation process of the magnetorheological elastomer of the present invention, multi-walled carbon nanotubes and soft carbon black are added, and epoxidized palm oil is added to improve the filler dispersion. The mechanical properties and magnetorheological effect of the magnetorheological elastomer prepared by this method have been greatly improved. And this modification will not affect the optimal volume concentration of magnetic particles in the magnetorheological elastomer.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent materials, and particularly to a magnetorheological elastomer with high mechanical strength and a preparation method thereof. Background Art

[0002] In the past decade or so, with the development of technology and the needs of mankind, intelligent materials have become one of the most eye-catching fields. Magnetorheological elastomers are mainly composed of non-magnetic matrices and magnetic particles. By adding magnetic particles to rubber, additional property changes can be achieved through magnetic particle interactions and interfacial damping. In addition, damping and stiffness can be controlled by applying a magnetic field during manufacturing or service. Since its mechanical properties and magnetorheological properties can be intelligently controlled by an external magnetic field. For example, when the magnetic field strength increases, its magnetorheological effect is manifested as a significant increase in Young's modulus and shear modulus. It has broad application prospects in military and civilian fields such as automotive and aircraft shock absorption, weapons, and high-speed rail. Of course, magnetorheological elastomers also face many technical bottlenecks, such as the magnetorheological effect being insufficient to meet the needs of intelligent applications, and the addition of iron powder causing damage to the rubber molecular network, thereby reducing the mechanical properties of the composite material. The root cause of these problems lies in the poor binding ability between magnetic particles and the rubber matrix. The incompatibility between magnetic particles and the matrix not only leads to poor interaction and wettability between the matrix and the particles, but also results in poor dispersion of the particles in the matrix, leading to low energy absorption, and further affecting the mechanical properties and viscoelasticity of the material. Therefore, a method is needed to improve its compatibility to enhance the performance of magnetorheological elastomers. Summary of the Invention

[0003] The purpose of the present invention is to provide a wound hemostasis and repair gel based on hyaluronic acid and a preparation method thereof to solve the problems raised in the above background art.

[0004] To solve the above technical problems, the present invention provides the following technical solutions: A magnetorheological elastomer with high mechanical strength, including the following characteristics: By weight, the magnetorheological elastomer with high mechanical strength includes the following components: 90 - 110 parts of rubber matrix, 200 - 300 parts of magnetic groups, 8 - 12 parts of dispersant, 10 - 15 parts of reinforcing agent, 7 - 9 parts of activator, 2 - 2.5 parts of accelerator, 5 - 9 parts of antioxidant, 1.5 - 2 parts of vulcanizing agent, 0.5 - 0.7 parts of peptizer, 4 - 6 parts of multi-walled carbon nanotubes, 13 - 15 parts of plasticizer. Further, the rubber matrix is any one of natural rubber and chloroprene rubber; the dispersant is epoxidized palm oil.

[0005] The effect of epoxidized palm oil as a dispersant on natural rubber-based magnetorheological elastomers is significant. Compared with traditional petroleum-based dispersants, it can not only improve the filler dispersion but also increase the matrix crosslinking density, thereby enhancing the magnetic properties, tensile strength, and elongation at break of the elastomer.

[0006] Further, the reinforcing agent is soft carbon black, specifically the fast extrusion furnace soft carbon black N550 particles;

[0007] The multi-walled carbon nanotubes have more than 10 layers. The inner diameter of the innermost carbon tube is about 1 nm, and the length is about 0.5 μm;

[0008] Multi-walled carbon nanotubes have a high aspect ratio. Different from single-walled carbon nanotubes, this structure has stronger anisotropy and higher strength and toughness. It can greatly enhance the mechanical strength of the material, and this enhancement is particularly prominent in the compression state. When used in combination with soft carbon black N550 particles as a reinforcing agent, the effect is better.

[0009] Further, the activator is a mixture of zinc oxide and stearic acid, where the mass ratio of zinc oxide to stearic acid is 4:1; the accelerator is a mixture of accelerator CZ and DM, where the mass ratio of accelerator CZ to accelerator DM is 3:1; the antioxidant is antioxidant 4010NA; the vulcanizing agent is sulfur; the peptizer is peptizer P-40; the plasticizer is paraffin oil.

[0010] Further, the magnetic group is a polymer of amino-group-containing carbonyl iron powder and iron oxide nanorods, prepared by the polymerization reaction of carbonyl iron powder treated with hydrochloric acid, hydroxyl iron oxide, and (3-aminopropyl)triethoxysilane;

[0011] Among them, the particle size of the carbonyl iron powder is 2 - 2.8 μm, and the length of the hydroxyl iron oxide nanorods is 120 - 180 nm, and the diameter is 8 - 12 nm.

[0012] A preparation method of a magnetorheological elastomer with high mechanical strength includes the following steps:

[0013] S1. Disperse the carbonyl iron powder in hydrochloric acid solution. After soaking for 50 - 70 min, filter and separate the carbonyl iron powder, wash it 3 - 5 times with methanol, and then vacuum dry it to constant weight. Mix the washed carbonyl iron powder with iron oxide nanorods, disperse them in methanol, add dropwise (3-aminopropyl)triethoxysilane to obtain a mixed solution. Heat the solution to 55 - 65 °C, stir and react for 18 - 30 hours, then filter and separate the reaction polymer, wash it 3 - 5 times with pure methanol, and vacuum dry it to constant weight to obtain the magnetic group;

[0014] S2. Mix the rubber matrix, activator and peptizer, and after kneading for 4 - 6 minutes, add the dispersant, magnetic groups, multi-walled carbon nanotubes, and reinforcing agent, and continue kneading for 10 - 15 minutes;

[0015] S3. Add the plasticizer, anti-aging agent, accelerator, and sulfur and continue kneading for 4 - 6 minutes, then pass through a thin sheet to obtain the kneaded rubber; After placing the kneaded rubber in a dry and cool place for 24 hours, pass through a thin sheet 2 - 3 times; Vulcanize the kneaded rubber to obtain a magnetorheological elastomer with high mechanical strength.

[0016] The group structure feature is centered on a micron-sized magnetic particle, and nano-sized rod-shaped magnetic microparticles are linked around it.

[0017] Further, in step S1, the concentration of the hydrochloric acid solution is 0.4 - 0.6 mol / L. This concentration of hydrochloric acid can well generate and activate hydroxyl groups on the surface of carbonyl iron powder, activate its surface, so as to facilitate polymerization with (3-aminopropyl)triethoxysilane.

[0018] Further, in step S1, the particle size of the carbonyl iron powder is 2 - 2.8 μm, the length of the iron oxide hydroxide nanorods is 120 - 180 nm, and the diameter is 8 - 12 nm. At this size ratio, it will not affect the optimal magnetic particle concentration, and can increase the magnetic particle coupling interaction and improve the magnetorheological effect of the material.

[0019] Further, by weight, in step S1, the mass ratio of the washed carbonyl iron powder to the iron oxide hydroxide nanorods is (8 - 12):1.

[0020] Further, in step S1, in the mixed solution, the concentration of (3-aminopropyl)triethoxysilane is 10 - 20 g / L.

[0021] Further, in step S3, the vulcanization temperature is 140 - 150 °C, and the vulcanization pressure is 8 - 12 MPa.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0023] 1. Multi-walled carbon nanotubes have a good strengthening effect, form an efficient filler network, and their high aspect ratio and dispersibility provide higher stiffness and improve the compression load core, so that their load-bearing capacity and mechanical strength as shock absorbers are greatly improved;

[0024] 2. The magnetic groups are bonded stronger to the rubber matrix, and the combination of the two is excellent, avoiding voids at the bonding interface, effectively reducing the pseudoplasticity of the magnetorheological elastomer, and the addition of soft carbon black increases the crosslinking density of the magnetorheological elastomer. Under the synergistic action of the two, the stress softening effect of the magnetorheological elastomer is reduced. It can be more applied to actual industrial needs;

[0025] 3. The preparation method of isotropic magnetorheological elastomer is much simpler than that of anisotropic magnetorheological elastomer, because it does not need to be pre-structured under a magnetic field to form a chain structure of magnetic particles, but its magnetorheological effect is not obvious enough, so it is difficult to use effectively. The addition of magnetic groups effectively improves the magnetorheological effect of isotropic magnetorheological elastomer, which solves this problem to a large extent;

[0026] 4. Magnetorheological elastomers usually pursue higher magnetorheological effects, which results in poor mechanical properties and low strength of composite materials. The synergistic effect of magnetic groups, multi-walled carbon nanotubes and soft carbon black dispersed in epoxidized palm oil effectively solves the problem of poor mechanical strength of magnetorheological elastomers, comprehensively improves its mechanical properties in all aspects, and broadens its application direction and application field. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 is a SEM scan of the magnetorheological elastomer prepared in Example 1 of the present invention;

[0029] Figure 2 This is a SEM scan of the magnetorheological elastomer prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0031] In the examples and comparative examples of the present application, the natural rubber grade RSS1 was purchased from China Hainan Rubber Products Co., Ltd.; the chloroprene rubber grade SN 224X was purchased from Shanxi Shanna Synthetic Rubber Co., Ltd.; the carbonyl iron powder grade was MPS-MRF-25, purchased from Jiangsu Tianyi Superfine Metal Powder Co., Ltd.; the oxyhydroxide iron nanorods were purchased from Xi'an Qiyue Biotechnology Co., Ltd.; zinc oxide and stearic acid were purchased from Sigma-Aldrich; the dispersant and paraffin oil were purchased from Shanghai Xiangping Industrial Co., Ltd.; the antioxidant 4010NA, the accelerators CZ and DM and the plasticizer were purchased from Dongguan Baiyi Plastic Raw Materials Co., Ltd.; the soft carbon black N550 was purchased from Cabot Corporation; (3-aminopropyl)triethoxysilane was purchased from Nanjing Aocheng Chemical Co., Ltd., and the multi-walled carbon nanotubes were purchased from Chengdu Organic Chemistry Co., Ltd.; methanol, hydrochloric acid, etc. were all commercially available.

[0032] Example 1.

[0033] A preparation method of a magnetorheological elastomer with high mechanical strength, comprising the following steps:

[0034] S1. Disperse carbonyl iron powder in a hydrochloric acid solution with a concentration of 0.5 mol / L. After soaking for 60 min, filter and separate the carbonyl iron powder, wash it 3 times with methanol, and then vacuum dry it to constant weight. Mix the washed carbonyl iron powder and iron oxide hydroxide nanorods at a mass ratio of 10:1, disperse them in methanol, and add (3-aminopropyl)triethoxysilane dropwise to obtain a mixed solution, where the concentration of (3-aminopropyl)triethoxysilane in the mixed solution is 20 g / L. Heat the mixed solution to 60 °C and stir and react at a rate of 300 rpm for 24 hours. Then filter and separate the reaction polymer, wash it 5 times with pure methanol, and vacuum dry it at 60 °C to constant weight to obtain magnetic groups;

[0035] S2. At a temperature below 25 °C, take 100 g of natural rubber and put it into an open mill for mixing. After plasticizing and wrapping it around the roll, add 6 g of zinc oxide, 1.5 g of stearic acid, and 0.6 g of peptizer P-40 and continue mixing for 5 minutes until the powdery additives are evenly mixed. Add 10 g of epoxidized palm oil, 5 g of multi-walled carbon nanotubes, 275 g of magnetic groups, and 10 g of soft carbon black, and continue mixing for 10 minutes;

[0036] S3. Add 14 g of paraffin oil, 7 g of antioxidant 4010NA, 1.875 g of accelerator CZ, and 0.725 g of accelerator DM. Finally, add 1.75 g of sulfur and mix for 5 minutes, then thin-pass and sheet off. After placing the mixed rubber in a dry and cool place for 24 hours, thin-pass it 3 more times. Use a rotorless vulcanizer to obtain the process vulcanization time of the sample at 143 °C, where T90 is 210 s. Set the vulcanizer to a pressure of 10 MPa, a temperature of 143 °C, and a time of 330 s. After vulcanization by the vulcanizer, a magnetorheological elastomer with high mechanical strength is obtained.

[0037] Example 2.

[0038] A preparation method of a magnetorheological elastomer with high mechanical strength, comprising the following steps:

[0039] S1. Disperse carbonyl iron powder in a hydrochloric acid solution with a concentration of 0.5 mol / L. After soaking for 60 min, filter and separate the carbonyl iron powder, wash it 3 times with methanol, and then dry it in vacuum until constant weight. Mix the washed carbonyl iron powder and iron oxide hydroxide nanorods at a mass ratio of 10:1, disperse them in methanol, and dropwise add (3-aminopropyl)triethoxysilane to obtain a mixed solution. The concentration of (3-aminopropyl)triethoxysilane in the mixed solution is 20 g / L. Heat the mixed solution to 60 °C and stir and react at a rate of 300 rpm for 24 hours. Then, filter and separate the reaction polymer, wash it 5 times with pure methanol, and dry it in vacuum at 60 °C until constant weight to obtain magnetic groups;

[0040] S2. At an ambient temperature below 25 °C, take 100 g of chloroprene rubber and put it into an open mill for mixing. After plasticizing and wrapping it around the roll, add 6 g of zinc oxide, 1.5 g of stearic acid, and 0.6 g of plasticizer P-40, and continue mixing for 5 minutes until the powdery additives are evenly mixed. Then add 10 g of epoxidized palm oil, 5 g of multi-walled carbon nanotubes, 275 g of magnetic groups, and 10 g of soft carbon black, and continue mixing for 10 minutes;

[0041] S3. Add 14 g of paraffin oil, 7 g of antioxidant 4010NA, 1.875 g of accelerator CZ, and 0.725 g of accelerator DM. Finally, add 1.75 g of sulfur and mix for 5 minutes, then roll out thinly. After placing the mixed rubber in a dry and cool place for 24 hours, roll it out thinly 3 more times. Use a rotorless rheometer to obtain the processing vulcanization time of the sample at 143 °C, with T90 being 210 s. Set the rheometer to a pressure of 10 MPa, a temperature of 143 °C, and a time of 330 s. After vulcanization by the rheometer, a magnetorheological elastomer with high mechanical strength is obtained.

[0042] Comparative Example 1.

[0043] S1. At an ambient temperature below 25 °C, take 100 g of natural rubber and put it into an open mill for mixing. After plasticizing and wrapping it around the roll, add 6 g of zinc oxide, 1.5 g of stearic acid, 0.6 g of plasticizer P-40, 14 g of paraffin oil, 7 g of antioxidant 4010NA, 1.875 g of accelerator CZ, and 0.725 g of accelerator DM, and continue mixing for 15 minutes. Finally, add 1.75 g of sulfur and mix for 5 minutes, then roll out thinly. After placing the mixed rubber in a dry and cool place for 24 hours, roll it out thinly 3 more times. Use a rotorless rheometer to obtain the processing vulcanization time of the sample at 143 °C, with T90 being 220 s. Set the rheometer to a pressure of 10 MPa, a temperature of 143 °C, and a time of 220 s. After vulcanization by the rheometer, a magnetorheological elastomer with high mechanical strength is obtained.

[0044] Comparative Example 2.

[0045] A preparation method of a magnetorheological elastomer with high mechanical strength, comprising the following steps:

[0046] S1. Disperse carbonyl iron powder in a hydrochloric acid solution with a concentration of 0.5 mol / L. After soaking for 60 min, filter and separate the carbonyl iron powder, wash it 3 times with methanol, and then vacuum dry it to constant weight. Disperse the washed carbonyl iron powder in an ethanol solution with a concentration of 95 wt%, and add vinyltrimethoxysilane dropwise to obtain a mixed solution. The mass ratio of vinyltrimethoxysilane to carbonyl iron powder in the mixed solution is 2:98. Heat the mixed solution to 60 °C and stir and react at a rate of 300 rpm for 24 hours. Then, filter and separate the reaction polymer, wash it 5 times with pure methanol, and vacuum dry it at 60 °C to constant weight to obtain modified carbonyl iron powder;

[0047] S2. At an ambient temperature below 25 °C, put 100 g of natural rubber into an open mill for mixing. After plasticizing and wrapping it on the roll, add 6 g of zinc oxide, 1.5 g of stearic acid, and 0.6 g of peptizer P-40 and continue mixing for 5 minutes until the powdery additives are evenly mixed. Then add 10 g of epoxidized palm oil, 5 g of multi-walled carbon nanotubes, 275 g of modified carbonyl iron powder, and 10 g of soft carbon black, and continue mixing for 10 minutes;

[0048] S3. Add 14 g of paraffin oil, 7 g of antioxidant 4010NA, 1.875 g of accelerator CZ, and 0.725 g of accelerator DM. Finally, add 1.75 g of sulfur and mix for 5 minutes, then thin-pass and sheet. After placing the mixed rubber in a dry and cool place for 24 hours, thin-pass it 3 more times. Use a rotorless rheometer to obtain the processing vulcanization time of the sample at 143 °C, where T90 is 210 s. Set the rheometer to a pressure of 10 MPa, a temperature of 143 °C, and a time of 330 s. After vulcanization by the rheometer, a magnetorheological elastomer with high mechanical strength is obtained.

[0049] Comparative Example 3.

[0050] A preparation method of a magnetorheological elastomer with high mechanical strength, comprising the following steps:

[0051] S1. Disperse carbonyl iron powder in a hydrochloric acid solution with a concentration of 0.5 mol / L. After soaking for 60 min, filter and separate the carbonyl iron powder, wash it 3 times with methanol, and then vacuum dry it to constant weight. Mix the washed carbonyl iron powder and iron oxide hydroxide nanorods in a mass ratio of 10:1, and disperse them in methanol. Add (3-aminopropyl)triethoxysilane dropwise to obtain a mixed solution. The concentration of (3-aminopropyl)triethoxysilane in the mixed solution is 20 g / L. Heat the mixed solution to 60 °C and stir and react at a rate of 300 rpm for 24 hours. Then, filter and separate the reaction polymer, wash it 5 times with pure methanol, and vacuum dry it at 60 °C to constant weight to obtain magnetic groups;

[0052] S2. At a temperature below 25°C, take 100 g of natural rubber and put it into an open mill for mixing. After plasticizing and wrapping it around the roll, add 6 g of zinc oxide, 1.5 g of stearic acid, and 0.6 g of plasticizer P-40, and continue mixing for 5 minutes until the powdery additives are evenly mixed. Then add 10 g of epoxidized palm oil, 275 g of magnetic groups, and 10 g of soft carbon black, and continue mixing for 10 minutes;

[0053] S3. Add 14 g of paraffin oil, 7 g of antioxidant 4010NA, 1.875 g of accelerator CZ, and 0.725 g of accelerator DM. Finally, add 1.75 g of sulfur and mix for 5 minutes, then roll out thinly. After placing the mixed rubber in a dry and cool place for 24 hours, roll it out thinly 3 more times. Use a rotorless rheometer to obtain the processing vulcanization time of the sample at 143°C, with T90 being 210 s. Set the rheometer to a pressure of 10 MPa, a temperature of 143°C, and a time of 330 s. After vulcanization with the rheometer, a magnetorheological elastomer with high mechanical strength is obtained.

[0054] Comparative Example 4.

[0055] A method for preparing a magnetorheological elastomer with high mechanical strength, comprising the following steps:

[0056] S1. Disperse carbonyl iron powder in a hydrochloric acid solution with a concentration of 0.5 mol / L. After soaking for 60 min, filter and separate the carbonyl iron powder, wash it 3 times with methanol, and then vacuum dry it to constant weight. Mix the washed carbonyl iron powder and iron oxide hydroxide nanorods in a mass ratio of 10:1, and disperse them in methanol. Dropwise add (3-aminopropyl)triethoxysilane to obtain a mixed solution, where the concentration of (3-aminopropyl)triethoxysilane in the mixed solution is 20 g / L. Heat the mixed solution to 60°C and stir and react at a rate of 300 rpm for 24 hours. Then filter and separate the reaction polymer, wash it 5 times with pure methanol, and vacuum dry it at 60°C to constant weight to obtain magnetic groups;

[0057] S2. At a temperature below 25°C, take 100 g of natural rubber and put it into an open mill for mixing. After plasticizing and wrapping it around the roll, add 6 g of zinc oxide, 1.5 g of stearic acid, and 0.6 g of plasticizer P-40, and continue mixing for 5 minutes until the powdery additives are evenly mixed. Then add 10 g of epoxidized palm oil, 5 g of carbon nanotubes, 275 g of magnetic groups, and 10 g of soft carbon black, and continue mixing for 10 minutes;

[0058] S3. Add 14 g of paraffin oil, 7 g of antioxidant 4010NA, 1.875 g of accelerator CZ and 0.725 g of accelerator DM, and finally add 1.75 g of sulfur and knead for 5 minutes, then roll out thinly and cut into sheets. After placing the kneaded rubber in a dry and cool place for 24 hours, roll it out thinly 3 more times. Use a rotorless vulcanization instrument to obtain the process vulcanization time of the sample at 143 °C, with T90 being 210 s. Set the vulcanization instrument to a pressure of 10 MPa, a temperature of 143 °C, and a time of 330 s. After vulcanization by the vulcanization instrument, a magnetorheological elastomer with high mechanical strength is obtained.

[0059] Detection: Tensile strength is an important physical property of rubber composites. Use an electronic universal testing machine (model AGS-X-100kN, Shimadzu Corporation) to test the mechanical properties of the specimens prepared in Examples 1-2 and Comparative Examples 1-4. Test the tensile properties of each sample according to GB-T 528-2009, with a loading speed of 500 mm / min, and test the tensile strength of the test specimens and the modulus at a 300% strain; test the compression properties of the samples according to GB-T 7757-2009 and calculate the compression modulus of each sample; the magnetorheological effect is an important performance index of magnetorheological elastomers. Use an advanced rotational rheometer (Anton Paar, model: MCR 301) to test the magnetorheological effect of the samples. Test conditions: room temperature, frequency 5 Hz, strain amplitude 0.03%, magnetic field strength 0 - 1000 mT.

[0060]

[0061] As can be seen from the above table: The interfacial binding force between the magnetic groups and the natural rubber matrix is stronger, and the binding bonds between the magnetic particles and the matrix are more stable. This also makes it require more energy for the iron powder to break away from the rubber matrix, so its mechanical properties are greatly improved. The addition of multi-walled carbon nanotubes and carbon black further improves the anisotropy, mechanical strength, and crosslinking density of the material. Compared with Comparative Example 1 and Comparative Example 2, it can be clearly observed that the magnetorheological effect in the examples increases significantly. This shows that under a magnetic field, the magnetic groups exhibit a higher saturation magnetostrictive modulus compared to CIP and modified CIP, thereby enhancing the overall magneto-sensitivity of the material. Compared with Comparative Example 3, it can be clearly observed that multi-walled carbon nanotubes enhance the mechanical properties of the magnetorheological elastomer. In Comparative Example 4, due to the absence of epoxidized palm oil, the dispersibility of the material is poor, resulting in a relatively high initial modulus of the material and a decrease in the magnetorheological effect. This proves the important role of epoxidized palm oil in the preparation process. According to the specific implementation method of the present invention, in Example 1 compared with Comparative Example 1, its tensile strength, modulus at a 300% strain, compression modulus, and magnetorheological effect have all been significantly improved. The tensile strength has increased by nearly 80%, the modulus at a 300% strain has increased by nearly 100%, the compression modulus at a 10% compression strain has increased by 133%, and the magnetorheological effect of the magnetorheological elastomer has increased by 536%;

[0062] and by Figure 1 , Figure 2 comparison, it can be observed that the combination of the novel magnetic particles and the rubber matrix is excellent, which proves that the modified CIP particles have higher affinity. Figure 2 It can be seen that there are many voids between the magnetic particles prepared by the conventional method and the matrix, the bonding is unstable, and the magnetic particles are likely to fall off from the matrix, while Figure 1 it can be observed that the magnetic groups can form a good combination with the matrix, the magnetic particles are embedded in the matrix, there are basically no voids, and the internal molecular structure is more stable.

[0063] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0064] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A magnetorheological elastomer with high mechanical strength, characterized in that: By weight, the magnetorheological elastomer with high mechanical strength comprises the following components: 90 - 110 parts of rubber matrix, 200 - 300 parts of magnetic groups, 8 - 12 parts of dispersant, 10 - 15 parts of reinforcing agent, 7 - 9 parts of activator, 2 - 2.5 parts of accelerator, 5 - 9 parts of antioxidant, 1.5 - 2 parts of vulcanizing agent, 0.5 - 0.7 part of peptizer, 4 - 6 parts of multi - walled carbon nanotubes, 13 - 15 parts of plasticizer; The magnetic group is a polymer of amino - group - bearing carbonyl iron powder and iron oxide nanorods, which is prepared by the polymerization reaction of carbonyl iron powder treated with hydrochloric acid, hydroxyl iron oxide and (3 - aminopropyl) triethoxysilane.

2. A magnetorheological elastomer with high mechanical strength according to claim 1, characterized in that: The rubber matrix is any one of natural rubber and chloroprene rubber; the dispersant is epoxidized palm oil.

3. A magnetorheological elastomer with high mechanical strength according to claim 1, characterized in that: The reinforcing agent is soft carbon black; The multi - walled carbon nanotubes have more than 10 layers of multi - walled carbon nanotubes, the inner - most carbon tube has an inner diameter of 1 nm and a length of 0.5 μm.

4. A magnetorheological elastomer with high mechanical strength according to claim 1, characterized in that: The activator is a mixture of zinc oxide and stearic acid, wherein the mass ratio of zinc oxide to stearic acid is 4:1; the accelerator is a mixture of accelerator CZ and DM, wherein the mass ratio of accelerator CZ to accelerator DM is 3:1; the antioxidant is antioxidant 4010NA; the vulcanizing agent is sulfur; the peptizer is peptizer P - 40; the plasticizer is paraffin oil.

5. A magnetorheological elastomer with high mechanical strength according to claim 1, characterized in that: The carbonyl iron powder has a particle size of 2 - 2.8 μm, and the hydroxyl iron oxide nanorods have a length of 120 - 180 nm and a diameter of 8 - 12 nm.

6. A preparation method of a magnetorheological elastomer with high mechanical strength, characterized in that, comprises the following steps: S1. Disperse carbonyl iron powder in hydrochloric acid solution, after soaking for 50 - 70 min, filter and separate the carbonyl iron powder, wash it with methanol 3 - 5 times, then vacuum - dry to constant weight. Mix the washed carbonyl iron powder with iron oxide hydroxide nanorods, disperse them in methanol, dropwise add (3 - aminopropyl) triethoxysilane to obtain a mixed solution. Heat the solution to 55 - 65 °C, stir and react for 18 - 30 hours, then filter and separate the reaction polymer, wash it with pure methanol 3 - 5 times, and vacuum - dry to constant weight to obtain magnetic groups; S2. Mix the rubber matrix, activator and peptizer, knead for 4 - 6 minutes, then add the dispersant, magnetic groups, multi - walled carbon nanotubes and reinforcing agent, and continue to knead for 10 - 15 minutes; S3. Add plasticizer, anti-aging agent, accelerator, and sulfur, and continue mixing for 4 - 6 minutes. Then, obtain the mixed rubber by passing it through thin sheets. After placing the mixed rubber in a dry and cool place for 24 hours, pass it through thin sheets 2 - 3 more times. Vulcanize the mixed rubber to obtain a magnetorheological elastomer with high mechanical strength.

7. A preparation method of a magnetorheological elastomer with high mechanical strength according to claim 6, characterized in that: In step S1, the concentration of the hydrochloric acid solution is 0.4 - 0.6 mol / L.

8. A preparation method of a magnetorheological elastomer with high mechanical strength according to claim 6, characterized in that: By weight, in step S1, the mass ratio of the washed carbonyl iron powder to the iron oxide hydroxide nanorods is (8 - 12):1; in the mixed solution, the concentration of (3-aminopropyl)triethoxysilane is 10 - 20 g / L.

9. A preparation method of a magnetorheological elastomer with high mechanical strength according to claim 6, characterized in that: In step S3, the vulcanization temperature is 140 - 150 °C, and the vulcanization pressure is 8 - 12 MPa.

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