A magnetorheological elastomer with a reticular particle chain structure and a preparation method thereof

Abstract

The present invention relates to the technical field of magnetorheological intelligent materials, and particularly relates to a magnetorheological elastomer with a reticular particle chain structure and a preparation method thereof. It is formed by splicing multiple magnetoelastic units with the same structure. Each of the magnetoelastic units includes an elastic matrix and multiple magnetic chains fixed in the elastic matrix in a reticular form. The cross-section of the elastic matrix of each magnetoelastic unit is square, and multiple concentric square magnetic chain loops are arranged in increasing order from the center of the square. The deflection angle between the magnetic chain loops and the elastic matrix is 15°-75°. For the magnetorheological elastomer with a reticular particle chain structure of the present invention, since the magnetic chains in the elastic matrix have a certain inclination angle, and there is a certain angle between the combined magnetic chain loops and the elastic matrix, its mechanical properties and magnetorheological effect can be further improved.

Description

Technical Field

[0001] The invention relates to the technical field of magnetorheological smart materials, and in particular to a magnetorheological elastomer with a mesh particle chain structure and a preparation method thereof. Background Art

[0002] Magnetorheological elastomers, as a new branch of magnetorheological smart materials, are mainly composed of high molecular polymers and micron-sized soft magnetic particles. Depending on whether the material is placed in an external magnetic field during curing, isotropic magnetorheological elastomers or anisotropic magnetorheological elastomers can be prepared. After curing, the magnetic particles are fixed in the magnetorheological elastomer matrix. Under the action of the external magnetic field, the magnetic interaction between adjacent magnetizable particles changes the stiffness and damping of the magnetorheological elastomer. After the magnetic field is removed, the magnetic interaction force between the particles disappears, and the microstructure of the magnetorheological elastomer quickly returns to its initial state. It can be seen that by applying a magnetic field, the mechanical properties of magnetorheological elastomer materials can be changed quickly, reversibly and controllably. The adjustment amount of the mechanical properties of the magnetorheological elastomer under the action of the magnetic field is its magnetorheological effect, which is an important criterion for judging its performance. Summary of the invention

[0003] One of the purposes of the present invention is to provide a magnetorheological elastomer with a network particle chain structure, which can improve its mechanical properties and magnetorheological effect to a certain extent.

[0004] The second object of the present invention is to provide a method for preparing a magnetorheological elastomer with a network particle chain structure, which is simple and easy to adjust.

[0005] The solution adopted by the present invention to achieve one of the purposes is: a magnetorheological elastomer with a mesh particle chain structure, which is spliced ​​by multiple magnetic elastomer units with the same structure, each of the magnetic elastomer units includes an elastic matrix and multiple magnetic chains in a mesh fixed in the elastic matrix, the cross-section of the elastic matrix of each magnetic elastomer unit is square, and multiple circles of square magnetic chain rings are arranged in increasing order from the center of the square to the outside, and the deflection angle between the magnetic chain ring and the elastic matrix is ​​15°-75°.

[0006] Preferably, each of the magnetic elastomer units is formed by rotating and splicing four rectangular magnetic elastomer structural parts of the same structure, and each magnetic elastomer structural part includes a rectangular elastic base and a plurality of magnetic chains that are parallel to each other and obliquely fixed in the elastic base, and the parallel arrangement direction of the plurality of magnetic chains is consistent with the radial extension direction of the rectangular magnetic elastomer structural part.

[0007] The solution adopted by the present invention to achieve the second purpose is: a method for preparing the magnetorheological elastomer with a network particle chain structure, comprising the following steps:

[0008] (1) Weigh component A, component B and carbonyl iron particles of the two-component liquid silicone rubber respectively, divide the carbonyl iron particles into two parts, and mix them evenly with component A and component B respectively;

[0009] (2) mixing the two mixed systems obtained in step (1) in a certain ratio and then degassing;

[0010] (3) fixing the degassed mixture at an angle in a magnetic field for pre-structuring so that the carbonyl iron particles are arranged in chains in the direction of the external magnetic field;

[0011] (4) After the structuring is completed, the material is cured at a certain temperature to obtain a magnetorheological elastomer;

[0012] (5) The solidified sample is divided into magnetic elastomer structural parts with the same structure, and the divided parts are rotated as needed and then bonded and solidified, so as to finally obtain a magnetorheological elastomer with a mesh particle chain structure composed of multiple magnetic elastomer units with the same structure.

[0013] Preferably, in step (1), component A of the two-component liquid silicone rubber is a platinum-containing catalyst, component B is hydrogen-containing silicone oil, and the mass ratio of component A to component B is 1:1.

[0014] Preferably, in step (1), the carbonyl iron particles account for 30%-70% of the total mass of the two-component liquid silicone rubber and the carbonyl iron particles, and the carbonyl iron particles are evenly divided into two parts and mixed with component A and component B respectively.

[0015] Preferably, in step (2), the two mixed systems are mixed in a mass ratio of 1:1.

[0016] Preferably, in step (3), the angle between the sample and the magnetic field is 15°-75°, and the magnetic field strength is 100-200 mT.

[0017] Preferably, in step (4), the curing temperature is 25-120°C.

[0018] The present invention has the following advantages and beneficial effects:

[0019] (1) The magnetorheological elastomer with a network particle chain structure of the present invention can further improve its mechanical properties and magnetorheological effect because the magnetic chains in the elastic matrix have a certain inclination angle and there is a certain angle between the assembled magnetic chain loops and the elastic matrix.

[0020] (2) The preparation method of the present invention pre-structures the mixed, uncured magnetorheological elastomer mixture in a magnetic field at a certain angle, so that the ferromagnetic particles in the prepared magnetorheological elastomer have a chain arrangement with a certain inclination angle, and then cuts and bonds the cured sample to prepare a magnetorheological elastomer with a network structure, which is beneficial to further improve its mechanical properties and magnetorheological effect.

[0021] (3) The preparation method of the present invention is highly operable, the process is relatively simple, the preparation process consumes a short time, and the preparation energy consumption is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of manufacturing the magnetorheological elastomer with mesh particle chain structure of the present invention;

[0023] Figure 2 The figure is a schematic diagram of the manufactured magnetorheological elastomer sample and the proportional division of the sample;

[0024] Figure 3 A schematic diagram of rotating and rearranging the segmented sample;

[0025] Figure 4 A schematic diagram of splicing and bonding the rotated sample;

[0026] Figure 5 A schematic diagram of the cross-sectional structure of a magnetorheological elastomer with a mesh particle chain structure after assembly and bonding;

[0027] Figure 6 6a is the shear force-displacement curve of the magnetorheological elastomer of each sample when no magnetic field is applied. Figure 6 b is the shear force-displacement curve of the magnetorheological elastomer of each sample after applying a magnetic field. DETAILED DESCRIPTION

[0028] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.

[0029] In the following examples, the magnetic particles used are carbonyl iron particles, and the matrix used is low-viscosity room temperature curing two-component liquid silicone rubber, HY-E600, provided by Shenzhen Hongyejie Technology Co., Ltd. HY-E600 is an addition mold silicone rubber, usually also called two-component room temperature vulcanized addition silicone rubber (hereinafter referred to as silicone rubber). The silicone rubber components A and B are both liquids with flowability, wherein component A contains platinum catalyst or other additives, and component B is hydrogen-containing silicone oil. After mixing, the two components A and B can be cured at room temperature or heated.

[0030] Example 1

[0031] like Figure 1 The preparation flow chart of the present invention is shown, and a preparation method of a magnetorheological elastomer with a network particle chain structure comprises the following steps:

[0032] 1) Take a certain mass of carbonyl iron particles, grind and dry them to disperse the particles, and then put them into a clean glass beaker.

[0033] 2) Take a clean beaker, first add the A component rubber, then add half of the carbonyl iron particles, and then place the A component / carbonyl iron particle mixture on a mechanical stirrer for stirring (stirring speed is 120r / min, stirring time is 5min) to obtain a uniformly mixed A component / carbonyl iron particle mixture.

[0034] 3) At the same time, take another clean beaker, add the B component rubber, and then add the other half of the carbonyl iron particles, and prepare the B component / carbonyl iron particle mixture in the same way.

[0035] 4) Slowly pour the stirred component B / carbonyl iron particle mixture into the component A / carbonyl iron particle mixture (control the mass ratio of the component A mixture to the component B mixture to be 1:1), the mass of the carbonyl iron particles in the mixture accounts for 70% of the mass of the total mixture system, and place the AB component mixture on a mechanical stirrer for stirring (stirring speed of 120r / min, stirring time of 5min).

[0036] 5) Slowly pour the stirred AB component mixture into the prepared cubic aluminum mold, and then place the mold in a vacuum box to evacuate the vacuum (the temperature in the vacuum box should be maintained at room temperature, and the vacuum time is 10 minutes). After the vacuum is completed, take out the mold and compact the AB mixture with a square transparent plastic sheet.

[0037] 6) After the mold and the sheet are pressed and fixed, place them at an angle of 30° (i.e. Figure 1 The sample was placed on a fixture with an angle θ in the center, and then placed in a 120mT magnetic field environment for pre-structuring (the pre-structuring time was 30min). After the pre-structuring was completed, it was placed in a 60°C constant temperature drying oven for curing (the curing time was 2h). The cured sample was an anisotropic magnetorheological elastomer.

[0038] 7) Place the finished sample on a clean glass sheet, define the plane where the magnetic chain is located as the cross section of the elastic matrix, and make proportional cuts along the longitudinal section of the elastic matrix, such as Figure 2 As shown, a plurality of long strip magnetic elastic body structures with square cross sections are obtained. After cutting, some rectangular samples are rotated, as shown in FIG. Figure 3As shown, every four magnetic elastomer structural parts are spliced ​​into a magnetic elastomer unit to obtain a magnetorheological elastomer with a mesh structure formed by splicing multiple magnetic elastomer units. Each magnetic elastomer unit includes an elastic matrix and multiple magnetic chains in a mesh fixed in the elastic matrix. The cross-section of the elastic matrix of each magnetic elastomer unit is square, and multiple circles of square magnetic chain rings are arranged in increasing order from the center of the square outward. The deflection angle between the magnetic chain ring and the elastic matrix is ​​30°. The long strip magnetic elastomer structural parts after rotation are spliced ​​and bonded, as shown Figure 4 As shown, Figure 5 The figure shows a schematic diagram of the cross-sectional structure of a magnetorheological elastomer with a mesh particle chain structure that has been assembled and bonded, and then the adjacent magnetic elastomer structural parts are bonded using a strong silicone adhesive to finally obtain a magnetorheological elastomer with a mesh particle chain structure of carbonyl iron particles.

[0039] Figure 6 The shear force-displacement curve of magnetorheological elastomer with network distribution structure is given. Figure 6 The traditional method for preparing a unidirectional 0° (i.e. Figure 2 The magnetorheological elastomer of the particle chain and the unjoined unidirectional 30° tilt angle (such as Figure 2 6a is the shear force-displacement curve of the magnetorheological elastomer of each sample when no magnetic field is applied, Figure 6 b is the shear force-displacement curve of the magnetorheological elastomer of each sample after applying a 120mT magnetic field. It can be seen from the figure that in the absence of a magnetic field and magnetization, the shear force of the magnetorheological elastomer with a unidirectional 30° tilt angle is higher than that of the 0° magnetorheological elastomer, but there is a disadvantage of stress asymmetry when loading in the positive and negative directions, which is not conducive to application. In the absence of a magnetic field and magnetization, the shear force of the magnetorheological elastomer with a designed mesh particle chain structure is higher than that of the 0° magnetorheological elastomer, and the bearing capacity in different loading directions is symmetrical. This shows that the mesh structure magnetorheological elastomer has superior mechanical properties.

[0040] Example 2

[0041] A method for preparing a magnetorheological elastomer with a network particle chain structure comprises the following steps:

[0042] 1) Take a certain mass of carbonyl iron particles, grind and dry them to disperse the particles, and then put them into a clean glass beaker.

[0043] 2) Take a clean beaker, first add the A component rubber, then add half of the carbonyl iron particles, and then place the A component / carbonyl iron particle mixture on a mechanical stirrer for stirring (stirring speed is 120r / min, stirring time is 5min) to obtain a uniformly mixed A component / carbonyl iron particle mixture.

[0044] 3) At the same time, take another clean beaker, add the B component rubber, and then add the other half of the carbonyl iron particles, and prepare the B component / carbonyl iron particle mixture in the same way.

[0045] 4) Slowly pour the stirred component B / carbonyl iron particle mixture into the component A / carbonyl iron particle mixture (control the mass ratio of the component A mixture to the component B mixture to be 1:1), the mass of the carbonyl iron particles in the mixture accounts for 30% of the mass of the total mixture system, and place the AB component mixture on a mechanical stirrer for stirring (stirring speed of 120r / min, stirring time of 5min).

[0046] 5) Slowly pour the stirred AB component mixture into the prepared cubic aluminum mold, and then place the mold in a vacuum box to evacuate the vacuum (the temperature in the vacuum box should be maintained at room temperature, and the vacuum time is 10 minutes). After the vacuum is completed, take out the mold and compact the AB mixture with a square transparent plastic sheet.

[0047] 6) After the mold and the sheet are pressed and fixed, place them at an angle of 15° (i.e. Figure 1 The sample was placed on a fixture with an angle θ in the center, and then placed in a 100mT magnetic field environment for pre-structuring (the pre-structuring time was 30min). After the pre-structuring was completed, it was placed in a 25°C constant temperature drying oven for curing (the curing time was 2h). The cured sample was an anisotropic magnetorheological elastomer.

[0048] 7) Place the finished sample on a clean glass sheet, define the plane where the magnetic chain is located as the cross section of the elastic matrix, and make proportional cuts along the longitudinal section of the elastic matrix, such as Figure 2 As shown, a plurality of long strip magnetic elastic body structures with square cross sections are obtained. After cutting, some rectangular samples are rotated, as shown in FIG. Figure 3 As shown, every four magnetic elastomer structural parts are spliced ​​into a magnetic elastomer unit to obtain a magnetorheological elastomer with a mesh structure formed by splicing multiple magnetic elastomer units. Each magnetic elastomer unit includes an elastic matrix and multiple magnetic chains fixed in the elastic matrix in a mesh. The cross-section of the elastic matrix of each magnetic elastomer unit is square, and multiple circles of square magnetic chain rings are arranged in increasing order from the center of the square outward. The deflection angle between the magnetic chain ring and the elastic matrix is ​​15°. The long strip magnetic elastomer structural parts after rotation are spliced ​​and bonded, as shown Figure 4 As shown, Figure 5 The figure shows a schematic diagram of the cross-sectional structure of a magnetorheological elastomer with a mesh particle chain structure that has been assembled and bonded, and then the adjacent magnetic elastomer structural parts are bonded using a strong silicone adhesive to finally obtain a magnetorheological elastomer with a mesh particle chain structure of carbonyl iron particles.

[0049] Example 3

[0050] A method for preparing a magnetorheological elastomer with a network particle chain structure comprises the following steps:

[0051] 1) Take a certain mass of carbonyl iron particles, grind and dry them to disperse the particles, and then put them into a clean glass beaker.

[0052] 2) Take a clean beaker, first add the A component rubber, then add half of the carbonyl iron particles, and then place the A component / carbonyl iron particle mixture on a mechanical stirrer for stirring (stirring speed is 120r / min, stirring time is 5min) to obtain a uniformly mixed A component / carbonyl iron particle mixture.

[0053] 3) At the same time, take another clean beaker, add the B component rubber, and then add the other half of the carbonyl iron particles, and prepare the B component / carbonyl iron particle mixture in the same way.

[0054] 4) Slowly pour the stirred component B / carbonyl iron particle mixture into the component A / carbonyl iron particle mixture (control the mass ratio of the component A mixture to the component B mixture to be 1:1), the mass of the carbonyl iron particles in the mixture accounts for 50% of the mass of the total mixture system, and place the AB component mixture on a mechanical stirrer for stirring (stirring speed of 120r / min, stirring time of 5min).

[0055] 5) Slowly pour the stirred AB component mixture into the prepared cubic aluminum mold, and then place the mold in a vacuum box to evacuate the vacuum (the temperature in the vacuum box should be maintained at room temperature, and the vacuum time is 10 minutes). After the vacuum is completed, take out the mold and compact the AB mixture with a square transparent plastic sheet.

[0056] 6) After the mold and the sheet are pressed and fixed, place them at an angle of 75° (i.e. Figure 1 The sample was placed on a fixture with an angle θ in the center, and then placed in a 200mT magnetic field environment for pre-structuring (the pre-structuring time was 30min). After the pre-structuring was completed, it was placed in a 120°C constant temperature drying oven for curing (the curing time was 2h). The cured sample was an anisotropic magnetorheological elastomer.

[0057] 7) Place the finished sample on a clean glass sheet, define the plane where the magnetic chain is located as the cross section of the elastic matrix, and make proportional cuts along the longitudinal section of the elastic matrix, such as Figure 2 As shown, a plurality of long strip magnetic elastic body structures with square cross sections are obtained. After cutting, some rectangular samples are rotated, as shown in FIG. Figure 3 As shown, every four magnetic elastomer structural parts are spliced ​​into a magnetic elastomer unit to obtain a magnetorheological elastomer with a mesh structure formed by splicing multiple magnetic elastomer units. Each magnetic elastomer unit includes an elastic matrix and multiple magnetic chains fixed in the elastic matrix in a mesh. The cross-section of the elastic matrix of each magnetic elastomer unit is square, and multiple circles of square magnetic chain rings are arranged in increasing order from the center of the square outward. The deflection angle between the magnetic chain ring and the elastic matrix is ​​75°. The long strip magnetic elastomer structural parts after rotation are spliced ​​and bonded, as shown Figure 4 As shown, Figure 5 The figure shows a schematic diagram of the cross-sectional structure of a magnetorheological elastomer with a mesh particle chain structure that has been assembled and bonded, and then the adjacent magnetic elastomer structural parts are bonded using a strong silicone adhesive to finally obtain a magnetorheological elastomer with a mesh particle chain structure of carbonyl iron particles.

[0058] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A magnetorheological elastomer with a reticular particle chain structure, characterized in that: It is composed of multiple magneto - elastic units with the same structure. Each magneto - elastic unit includes an elastic matrix and a plurality of magnetic chains in a reticular form fixed in the elastic matrix. The cross - section of the elastic matrix of each magneto - elastic unit is square, and there are multiple concentric square magnetic chain loops arranged in increasing order from the center of the square. The deflection angle between the magnetic chain loop and the elastic matrix is 15° - 75°. Each magneto - elastic unit is formed by splicing four magneto - elastic structural members with the same structure after rotation. Each magneto - elastic structural member includes a cuboid - shaped elastic matrix and a plurality of magnetic chains that are parallel to each other and obliquely fixed in the elastic matrix. The parallel arrangement direction of the plurality of magnetic chains is consistent with the radial extension direction of the cuboid - shaped magneto - elastic structural member.

2. A preparation method of the magnetorheological elastomer with a reticular particle chain structure as claimed in claim 1, characterized in that, it includes the following steps: (1) Weigh components A, B of the two - component liquid silicone rubber and carbonyl iron particles respectively. Divide the carbonyl iron particles into two parts and mix them evenly with components A and B respectively; (2) Mix the two mixed systems obtained in step (1) evenly according to a certain ratio and then degas; (3) Fix the degassed mixture obliquely in a magnetic field for pre - structuring to make the carbonyl iron particles arrange in chains in the direction of the external magnetic field; (4) After the structuring is completed, cure the material at a certain temperature to obtain the magnetorheological elastomer; (5) Divide the cured sample into magneto - elastic structural members with the same structure. Rotate the divided parts as needed and then bond and cure them to finally obtain a magnetorheological elastomer with a reticular particle chain structure composed of multiple magneto - elastic units with the same structure.

3. The preparation method of the magnetorheological elastomer with a reticular particle chain structure as claimed in claim 2, characterized in that: In step (1), component A of the two - component liquid silicone rubber is a platinum - containing catalyst, component B is a hydrogen - containing silicone oil, and the mass ratio of component A to component B is 1:

1.

4. The preparation method of the magnetorheological elastomer with a reticular particle chain structure as claimed in claim 2, characterized in that: In step (1), the carbonyl iron particles account for 30% - 70% of the total mass of the two - component liquid silicone rubber and the carbonyl iron particles. Divide the carbonyl iron particles into two equal parts and mix them with components A and B respectively.

5. The preparation method of the magnetorheological elastomer with a reticular particle chain structure as claimed in claim 2, characterized in that: In step (2), the two mixed systems are mixed according to a mass ratio of 1:

1.

6. The preparation method of the magnetorheological elastomer with a reticular particle chain structure as claimed in claim 2, characterized in that: In step (3), the angle between the sample and the magnetic field is 15° - 75°, and the magnetic field strength is 100 - 200 mT.

7. The preparation method of the magnetorheological elastomer with a reticular particle chain structure as claimed in claim 2, characterized in that: In the step (4), the curing temperature is 25 - 120 °C.

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