阅读说明：本技术 基于微流控纺丝技术的磁流变弹性体及其制备方法 (Magnetorheological elastomer based on microfluidic spinning technology and preparation method thereof ) 是由 周彦粉 孙保杰 李晨晨 李东亮 王之惠 江亮 陈韶娟 于 2021-09-08 设计创作，主要内容包括：本发明涉及磁流变弹性体技术领域,特别涉及一种基于微流控纺丝技术的磁流变弹性体。该磁流变弹性体是利用微流控纺丝技术制备的以热塑性弹性体溶液为皮层,磁流变液及热塑性弹性体溶液为芯层的皮芯结构的磁流变弹性纤维,其中,磁流变液采用间歇填充的方式填充至芯层中。本发明还提供一种基于微流控纺丝技术的磁流变弹性体的制备方法,该制备方法不仅制备方法简单,且通过本发明的制备方法得到的磁流变弹性体,可用于减震、隔振等装置中,可以同时克服磁流变液易沉降和传统磁流变弹性体磁致效应差的技术问题,值得被广泛推广应用。(The invention relates to the technical field of magnetorheological elastomers, in particular to a magnetorheological elastomer based on a microfluidic spinning technology. The magnetorheological elastomer is a magnetorheological elastic fiber which is prepared by utilizing a microfluidic spinning technology and has a skin-core structure with a thermoplastic elastomer solution as a skin layer and magnetorheological fluid and the thermoplastic elastomer solution as a core layer, wherein the magnetorheological fluid is filled into the core layer in an intermittent filling mode. The invention also provides a preparation method of the magnetorheological elastomer based on the microfluidic spinning technology, the preparation method is simple, the magnetorheological elastomer obtained by the preparation method can be used in devices such as shock absorption devices and vibration isolation devices, the technical problems that the magnetorheological fluid is easy to settle and the traditional magnetorheological elastomer is poor in magnetic effect can be simultaneously solved, and the preparation method is worthy of wide popularization and application.)

1. A magnetorheological elastomer based on a microfluidic spinning technology is characterized in that: the magnetorheological elastomer is a magnetorheological elastic fiber which is prepared by utilizing a microfluidic spinning technology and has a skin-core structure with a thermoplastic elastomer solution as a skin layer and magnetorheological fluid and the thermoplastic elastomer solution as a core layer, wherein the magnetorheological fluid is filled into the core layer in an intermittent filling mode.

2. The magnetorheological elastomer based on the microfluidic spinning technology according to claim 1, which is characterized in that: the iron content of the magnetorheological fluid is 30-80 wt%, and the mass fraction of the thermoplastic elastomer solution is 10-60%.

3. The magnetorheological elastomer based on the microfluidic spinning technology according to claim 1, which is characterized in that: the thermoplastic elastomer comprises one or more of styrene-ethylene-butylene-styrene block copolymer (SEBS), Thermoplastic Polyurethane (TPU), styrene-butylene-styrene block copolymer (SBS), Silicon Rubber (SR), Natural Rubber (NR) and Styrene Butadiene Rubber (SBR).

4. The magnetorheological elastomer based on the microfluidic spinning technology according to claim 1, which is characterized in that: the interval length of the magnetorheological materials in the fiber core layer can be adjusted at will according to actual needs.

5. A method for preparing a magnetorheological elastomer based on a microfluidic spinning technology is characterized by comprising the following steps:

(1) preparing a thermoplastic elastomer solution and magnetorheological fluid, and mechanically stirring until the thermoplastic elastomer solution and the magnetorheological fluid are uniformly mixed for later use;

(2) adopting a microfluidic spinning technology, taking a thermoplastic elastomer solution as a skin layer spinning solution, taking magnetorheological fluid and a thermoplastic elastomer solution as a core layer, intermittently filling the thermoplastic elastomer solution and the magnetorheological fluid in the core layer to prepare a fiber with a skin-core structure, and solidifying in a solidification bath;

(3) and (3) drying the fiber spun in the step (2) at the temperature of 80 ℃ until the skin layer structure is completely solidified, thus obtaining the magnetorheological elastic fiber.

6. The preparation method of the magnetorheological elastomer based on the microfluidic spinning technology as claimed in claim 5, which is characterized in that: the thermoplastic elastomer solution comprises one or more of SEBS solution, TPU solution, SBS solution, SR solution, NR solution and SBR solution.

7. The preparation method of the magnetorheological elastomer based on the microfluidic spinning technology as claimed in claim 5, which is characterized in that: the mass fraction of the thermoplastic elastomer solution is 10-60%, and the iron content in the magnetorheological fluid is 30-80 wt%.

8. The preparation method of the magnetorheological elastomer based on the microfluidic spinning technology as claimed in claim 5, which is characterized in that: and (3) in the step (2), the ethanol with the mass fraction of 95% is adopted in the coagulating bath for coagulation treatment.

9. The preparation method of the magnetorheological elastomer based on the microfluidic spinning technology as claimed in claim 5, which is characterized in that: when the thermoplastic elastomer solution and the magnetorheological fluid of the core layer are intermittently filled, the intermittent filling time can be randomly adjusted and set according to actual requirements.

Technical Field

The invention relates to the technical field of magnetorheological elastomers, in particular to a magnetorheological elastomer based on a microfluidic spinning technology and a preparation method thereof.

Background

The magnetorheological material is an intelligent soft material prepared by dispersing micro-nano soft magnetic particles in different carriers, the rheological property of the magnetorheological material can be continuously, rapidly and reversibly changed along with an external magnetic field, and the magnetorheological material has wide application prospect in the field of active and semi-active vibration control. The magnetic rheological liquid is a kind of magnetic sensitive intelligent soft material developed at the earliest, and is a particle suspension system prepared by mixing micron-sized ferromagnetic particles into non-magnetic liquid, after a magnetic field is applied, the magnetic rheological liquid can be rapidly converted from a liquid state similar to Newtonian fluid into a quasi-solid state, the apparent viscosity can be changed by several orders of magnitude under the regulation and control of the magnetic field, and the obvious magnetic effect is shown. However, the magnetorheological fluid has the problem of particle sedimentation in the use process due to the large density difference between the ferromagnetic particles and the matrix. In order to thoroughly solve the problem of particle sedimentation, people use elastomer materials to replace a non-magnetic liquid continuous phase to prepare the magnetorheological elastomer.

The magnetorheological elastomer is a magnetic control intelligent material prepared by dispersing micron-sized soft magnetic particles into a polymer elastomer, and has excellent magnetic control mechanical properties. The magnetic deformation and the magnetic modulus are important magnetic control mechanical properties of the magnetorheological elastomer, the mechanical properties of the magnetorheological elastomer can be continuously, rapidly and reversibly changed under a magnetic field, and the magnetorheological elastomer has excellent application prospects in the aspects of flexible sensing, soft robots, flexible driving and the like. The change of the magneto-rheological property of the magneto-rheological elastomer is mainly originated from the magnetic particles, and the magnetic interaction force formed by the particles under a magnetic field can form uneven magnetic moment in the magneto-rheological elastomer, so that the magneto-rheological elastomer is driven to generate certain deformation and modulus change. However, the existing magnetorheological elastomer is influenced by the elastomer, and compared with the magnetorheological fluid, the magnetorheological elastomer has a lower magnetic effect, and meanwhile, the common form of the magnetorheological elastomer is a block or a film, so that the requirements of many practical applications are difficult to meet.

For example, patent CN 109818523B discloses a method for preparing a magnetorheological elastomer with programmable magnetic deformation, which specifically comprises the following steps: a. printing the magnetic wire material into magnetic short fibers with specific distribution and orientation by a 3D printer, and applying a magnetic field to regulate and control the magnetic domain of the short fibers in the printing process; b. b, packaging the magnetic short fibers printed in the step a by using silicon rubber, and curing to obtain a magnetorheological elastomer material with anisotropic magnetic moment inside; the magnetic short fibers with any distribution and orientation can be obtained by printing through the 3D printer, so that the magnetic moment of the magnetorheological elastomer under a magnetic field can be designed, any magnetic deformation characteristic can be obtained, the programmable deformation driving capability of the magnetorheological elastomer can be realized by designing the magnetic moment inside the magnetorheological elastomer, and the rich driving capability of the magnetorheological elastomer is endowed. For another example, patent CN l10669329A discloses a method for preparing a magnetorheological elastomer, specifically, micron-sized carbon fibers are selected to grow carbon nanotubes in situ on the surfaces of the carbon fibers by a chemical vapor deposition method, then silicon carbide is grown in situ on the surfaces of the carbon fibers by an electric spark plasma sintering technology to obtain a three-dimensional reinforcement as a reinforcing filler, polyurethane and silicon rubber are used as raw materials, and a vulcanizing agent, an accelerator, a plasticizer and ferromagnetic particles are combined to prepare the magnetorheological elastomer with good mechanical properties; the three-dimensional reinforcement prepared by using the carbon fiber as the reinforcement phase can improve the mechanical properties of the magnetorheological elastomer such as tensile strength, breaking strength and the like, increase the wear resistance of the magnetorheological elastomer, reduce the drying shrinkage of the magnetorheological elastomer, adjust the conductivity of the magnetorheological elastomer in a larger range, and enable the magnetorheological elastomer to have the functional characteristics of pressure sensitivity, thermoelectric effect, temperature resistance effect and the like.

Although the above patent uses silicone rubber for encapsulation, the purpose of preventing the magnetic particles in the magnetorheological elastomer from settling can also be achieved, the micron-sized soft magnetic particles are dispersed in the silicone rubber in a visco-plastic state, and the magnetic particles in the silicone rubber have weaker rheological property than the magnetorheological fluid, so that the magnetic effect of the magnetorheological elastomer is relatively lower, and the preparation method is more complicated.

In view of the above technical problems, there is a need to develop a magnetorheological elastomer capable of preventing magnetic particles from easily settling and maintaining a high magnetic effect.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to solve the technical problem of providing the magnetorheological elastomer based on the microfluidic spinning technology and the preparation method thereof, wherein the magnetorheological elastomer can effectively prevent the magnetic particles in the magnetofluid from settling, can ensure higher magnetic effect, and has the advantages of simple preparation method and low preparation cost.

The technical scheme adopted by the invention for realizing the purpose is as follows: the magnetorheological elastomer is a magnetorheological elastic fiber with a skin-core structure, wherein the magnetorheological elastic fiber is prepared by utilizing a microfluidic spinning technology and takes a thermoplastic elastomer solution as a skin layer and the magnetorheological fluid and the thermoplastic elastomer solution as a core layer, and the magnetorheological fluid is filled into the core layer in an intermittent filling mode.

The magnetorheological elastomer based on the microfluidic spinning technology has the advantages that the iron content in the magnetorheological fluid is 30-80 wt%, and the mass fraction of the thermoplastic elastomer solution is 10-60%.

The above magnetorheological elastomer based on the microfluidic spinning technology comprises one or more of styrene-ethylene-butylene-styrene block copolymer (SEBS), Thermoplastic Polyurethane (TPU), styrene-butylene-styrene block copolymer (SBS), Silicone Rubber (SR), Natural Rubber (NR) and Styrene Butadiene Rubber (SBR).

According to the magnetorheological elastomer based on the microfluidic spinning technology, the interval length of the magnetorheological materials in the fiber core layer can be adjusted at will according to actual needs.

A method for preparing a magnetorheological elastomer based on a microfluidic spinning technology comprises the following steps:

(1) preparing a thermoplastic elastomer solution and magnetorheological fluid, and mechanically stirring until the thermoplastic elastomer solution and the magnetorheological fluid are uniformly mixed for later use;

(2) adopting a microfluidic spinning technology, taking a thermoplastic elastomer solution as a skin layer spinning solution, taking magnetorheological fluid and a thermoplastic elastomer solution as a core layer, intermittently filling the thermoplastic elastomer solution and the magnetorheological fluid in the core layer to prepare a fiber with a skin-core structure, and solidifying in a solidification bath;

(3) and (3) drying the fiber spun in the step (2) at the temperature of 80 ℃ until the skin layer structure is completely solidified, thus obtaining the magnetorheological elastic fiber.

In the preparation method of the magnetorheological elastomer based on the microfluidic spinning technology, the thermoplastic elastomer solution comprises one or more of SEBS solution, TPU solution, SBS solution, SR solution, NR solution and SBR solution.

According to the preparation method of the magnetorheological elastomer based on the microfluidic spinning technology, the mass fraction of the thermoplastic elastomer solution is 10-60%, and the iron content in the magnetorheological fluid is 30-80 wt%.

In the preparation method of the magnetorheological elastomer based on the microfluidic spinning technology, in the step (2), the solidification bath is subjected to solidification treatment by adopting the ethanol with the mass fraction of 95%.

According to the preparation method of the magnetorheological elastomer based on the microfluidic spinning technology, when the thermoplastic elastomer solution of the core layer and the magnetorheological fluid are intermittently filled, the intermittent filling time can be arbitrarily adjusted and set according to actual needs.

The magnetorheological elastomer based on the microfluidic spinning technology has the beneficial effects that: the invention realizes the intermittent filling of the magnetorheological fluid in the elastic matrix by using the intermittent filling fiber of the sheath-core structure of the microfluidic spinning technology, realizes the encapsulation of the magnetorheological fluid in a minimum space, not only avoids the performance change after deposition, but also keeps higher magnetic effect, and overcomes the problems of easy sedimentation and poor stability of the magnetorheological fluid. And the programmed filling can realize that the elastomer shows different mechanical properties at different positions.

The preparation method of the magnetorheological elastomer based on the microfluidic spinning technology is simple, and the magnetorheological elastomer obtained by the preparation method can be used in devices for shock absorption, vibration isolation and the like, can simultaneously overcome the technical problems of easy sedimentation and poor magnetic effect of the magnetorheological fluid, and is worthy of wide popularization and application.

Drawings

FIG. 1 is a schematic perspective structural view of a magnetorheological fiber spinning device with a skin-core structure according to the invention;

fig. 2 is an enlarged schematic view of part a.

Detailed Description

The invention is further explained in detail with reference to the drawings and the specific embodiments;

example 1

The magnetorheological elastomer is a magnetorheological elastic fiber with a skin-core structure, wherein the magnetorheological elastic fiber is prepared by utilizing a microfluidic spinning technology and takes a thermoplastic elastomer solution as a skin layer and the magnetorheological fluid and the thermoplastic elastomer solution as a core layer, and the magnetorheological fluid is filled into the core layer in an intermittent filling mode.

In this embodiment, the content of carbonyl iron in the magnetorheological fluid is 30 wt%, the thermoplastic elastomer is SEBS, the mass fraction of the SEBS solution is 45%, and the interval length of the magnetorheological material in the fiber core layer can be arbitrarily adjusted according to actual needs. The filling amount of the magnetorheological fluid can be adjusted by a programmed filling mode, so that the elastomer can show different mechanical properties at different positions.

The magnetorheological elastomer is a fiber with a skin-core structure, the magnetorheological fluid is encapsulated in the fiber core layer at intervals, the magnetorheological fluid of the whole section of fiber is decomposed into the magnetorheological fluid of each small section of fiber by adopting a calculus mathematical concept, the technical problem of sedimentation of the magnetorheological fluid is integrally solved, and the magnetorheological fluid is adopted to replace the traditional magnetorheological elastomer which is obtained by dispersing micron-sized magnetic particles into a polymer elastomer, so that the magnetic effect can be greatly improved.

A method for preparing a magnetorheological elastomer based on a microfluidic spinning technology comprises the following steps:

(1) preparing a thermoplastic elastomer solution and a magnetorheological solution, and mechanically stirring the thermoplastic elastomer solution and the magnetorheological solution until the thermoplastic elastomer solution and the magnetorheological solution are uniformly mixed for later use; wherein the thermoplastic elastomer solution is SEBS solution, the mass fraction of the SEBS solution is 45%, and the iron content in the magnetorheological fluid is 30 wt%;

(2) adopting a microfluidic spinning technology, taking a thermoplastic elastomer solution as a skin layer spinning solution, taking magnetorheological fluid and a thermoplastic elastomer solution as a core layer, intermittently filling the thermoplastic elastomer solution and the magnetorheological fluid in the core layer to prepare a fiber with a skin-core structure, and solidifying in a solidification bath; wherein, in the step (2), the ethanol with the mass fraction of 95% is adopted in the coagulating bath for coagulation treatment; when the thermoplastic elastomer solution and the magnetorheological fluid of the core layer are intermittently filled, the intermittent filling time can be randomly adjusted and set according to actual needs;

(3) and (3) drying the fiber spun in the step (2) at the temperature of 80 ℃ until the skin layer structure is completely solidified, thus obtaining the magnetorheological elastic fiber.

The magnetorheological elastomer based on the microfluidic spinning technology is prepared by adopting a fiber spinning device shown in figure 1, and specifically comprises a container 2 for containing a coagulation bath solution 1, a supporting roller 3 and a winding roller 4 for winding and winding prepared magnetorheological elastic fibers, wherein the supporting roller 3 is provided with three coaxial needles 5, the coaxial needles 5 are connected with injectors 6 through hoses, one injector 6 is used for injecting a skin layer spinning solution 7 into the coagulation bath solution 1, the other injector is used for injecting a core layer magnetorheological fluid spinning solution 10, and the last injector is used for injecting a core layer thermoplastic elastomer spinning solution 11; when the core layer magnetorheological fluid spinning solution 10 and the core layer thermoplastic elastomer solution spinning solution 11 are injected, the control valve 12 is used for controlling the gap injection of the two core layer injection solutions, so that the purpose of intermittently filling the two core layer injection solutions is achieved, and finally the magnetorheological elastic fiber 13 with the skin-core structure is prepared and wound on the winding roller 4 as shown in figure 2.

Namely, the SEBS is used as an elastic matrix, the magnetorheological fluid with the carbonyl iron content of 30 wt% is used as a raw material, and the intermittent filling fiber with the skin-core structure is prepared by the microfluidic spinning technology. The magnetorheological fiber with the skin-core structure obtained by the intermittent filling method prepared by the invention can be prepared into tubular fabrics by adopting the traditional weaving technology, and then the tubular fabrics are prepared into shock absorbers with various shapes.

Example 2

The magnetorheological elastomer is a magnetorheological elastic fiber with a skin-core structure, wherein the magnetorheological elastic fiber is prepared by utilizing a microfluidic spinning technology and takes a thermoplastic elastomer solution as a skin layer and the magnetorheological fluid and the thermoplastic elastomer solution as a core layer, and the magnetorheological fluid is filled into the core layer in an intermittent filling mode.

In this embodiment, the content of iron in the magnetorheological fluid is 70 wt%, the thermoplastic elastomer is SEBS, the mass fraction of the SEBS solution is 20%, and the interval length of the magnetorheological material in the fiber core layer can be arbitrarily adjusted according to actual needs. The filling amount of the magnetorheological fluid can be adjusted by a programmed filling mode, so that the elastomer can show different mechanical properties at different positions.

A method for preparing a magnetorheological elastomer based on a microfluidic spinning technology comprises the following steps:

(1) preparing a thermoplastic elastomer solution and magnetorheological fluid, and mechanically stirring until the thermoplastic elastomer solution and the magnetorheological fluid are uniformly mixed for later use; wherein the thermoplastic elastomer solution is SEBS solution, the mass fraction of the SEBS solution is 20%, and the iron content in the magnetorheological fluid is 70 wt%;

(2) adopting a microfluidic spinning technology, taking a thermoplastic elastomer solution as a skin layer spinning solution, taking magnetorheological fluid and a thermoplastic elastomer solution as a core layer, intermittently filling the thermoplastic elastomer solution and the magnetorheological fluid in the core layer to prepare a fiber with a skin-core structure, and solidifying in a solidification bath; wherein, in the step (2), the ethanol with the mass fraction of 95% is adopted in the coagulating bath for coagulation treatment; when the thermoplastic elastomer solution and the magnetorheological fluid of the core layer are intermittently filled, the intermittent filling time can be randomly adjusted and set according to actual needs;

(3) and (3) drying the fiber spun in the step (2) at the temperature of 80 ℃ until the skin layer structure is completely solidified, thus obtaining the magnetorheological elastic fiber.

Aiming at the problems of low magnetic effect, easy sedimentation of magnetic particles and the like of the existing magnetorheological material, the invention uses a microfluidic spinning technology to realize the intermittent packaging of the magnetorheological fluid in the elastic matrix, controls the magnetic particles in a tiny space, avoids the performance change after sedimentation and simultaneously keeps higher magnetic effect.

Example 3

The magnetorheological elastomer is a magnetorheological elastic fiber with a skin-core structure, which is prepared by utilizing a microfluidic spinning technology and takes a thermoplastic elastomer solution as a skin layer and the magnetorheological fluid and the thermoplastic elastomer solution as a core layer, wherein the magnetorheological fluid is filled into the core layer in an intermittent filling mode.

In this embodiment, the content of iron in the magnetorheological fluid is 70 wt%, the thermoplastic elastomer is SEBS, and the interval length of the magnetorheological material in the fiber core layer can be arbitrarily adjusted according to actual needs. The filling amount of the magnetorheological fluid can be adjusted by a programmed filling mode, so that the elastomer can show different mechanical properties at different positions.

A method for preparing a magnetorheological elastomer based on a microfluidic spinning technology comprises the following steps:

(1) preparing a thermoplastic elastomer solution and magnetorheological fluid, and mechanically stirring until the thermoplastic elastomer solution and the magnetorheological fluid are uniformly mixed for later use; wherein the thermoplastic elastomer solution is SEBS solution, the mass fraction of the SEBS solution is 45%, and the iron content in the magnetorheological fluid is 70 wt%;

(2) adopting a microfluidic spinning technology, taking a thermoplastic elastomer solution as a skin layer spinning solution, taking magnetorheological fluid and a thermoplastic elastomer solution as a core layer, intermittently filling the thermoplastic elastomer solution and the magnetorheological fluid in the core layer to prepare a fiber with a skin-core structure, and solidifying in a solidification bath; wherein, in the step (2), the ethanol with the mass fraction of 95% is adopted in the coagulating bath for coagulation treatment; when the thermoplastic elastomer solution and the magnetorheological fluid of the core layer are intermittently filled, the intermittent filling time can be randomly adjusted and set according to actual needs;

(3) and (3) drying the fiber spun in the step (2) at the temperature of 80 ℃ until the skin layer structure is completely solidified, thus obtaining the magnetorheological elastic fiber.

Aiming at the problems of low magnetic effect, easy sedimentation of magnetic particles and the like in the existing research of using magnetorheological materials, the invention realizes the encapsulation of the magnetorheological fluid in a tiny space by using the intermittent filling of the magnetorheological fluid, overcomes the problems of easy sedimentation and poor stability of the magnetorheological fluid, and can realize that the elastomer shows different mechanical properties at different positions by filling in a programmed form.

Example 4

The same parts as those in embodiments 1, 2 and 3 are not repeated, except that in this embodiment, the thermoplastic elastomer solution of the skin layer is a magnetorheological elastomer solution mixed with micron-sized magnetic particles.

Example 5

The same points as those in embodiment 4 are not described again, except that in this embodiment, the thermoplastic elastomer solution of the core layer is a magnetorheological elastomer solution mixed with micron-sized magnetic particles.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made according to the spirit of the present disclosure should be covered within the scope of the present disclosure.