阅读说明：本技术 一种聚乙烯醇基电磁屏蔽用纤维材料及其制备方法 (Polyvinyl alcohol-based fiber material for electromagnetic shielding and preparation method thereof ) 是由 朱美芳 杨利军 潘亮 许文婷 费翔 于 2020-06-12 设计创作，主要内容包括：本发明涉及一种聚乙烯醇基电磁屏蔽用纤维材料及其制备方法。该方法包括：将石墨烯加入Mxene离心液中,搅拌,加入丙烯酸单体和引发剂,共聚合反应,向得到的石墨烯/Mxene混合分散液中加入聚乙烯醇,然后湿法纺丝。该方法可以实现石墨烯和Mxene在聚合物基体中均匀分散,解决了纺丝可纺性差的难题,制备得到的纤维材料具有优良电磁屏蔽性能。(The invention relates to a polyvinyl alcohol-based fiber material for electromagnetic shielding and a preparation method thereof. The method comprises the following steps: adding graphene into Mxene centrifugate, stirring, adding an acrylic monomer and an initiator, carrying out copolymerization reaction, adding polyvinyl alcohol into the obtained graphene/Mxene mixed dispersion liquid, and then carrying out wet spinning. The method can realize the uniform dispersion of the graphene and the Mxene in the polymer matrix, solves the problem of poor spinnability of spinning, and the prepared fiber material has excellent electromagnetic shielding performance.)

1. A polyvinyl alcohol-based fiber material for electromagnetic shielding is prepared by adding graphene into Mxene centrifugate, stirring, adding acrylic acid monomer and initiator, carrying out copolymerization reaction, adding polyvinyl alcohol, and carrying out wet spinning.

2. A preparation method of a polyvinyl alcohol-based fiber material for electromagnetic shielding comprises the following steps:

(1) mixing Ti₃AlC₂Adding the mixture into an etching agent for etching, carrying out suction filtration and water washing, placing the obtained multilayer expanded Mxene into a dispersion liquid containing polyvinyl alcohol, carrying out ultrasonic stripping to obtain an Mxene dispersion liquid, and centrifuging to obtain a supernatant;

(2) adding graphene into the Mxene centrifugate obtained in the step (1), stirring, adding an acrylic monomer and an initiator, and carrying out copolymerization reaction to obtain a graphene/Mxene mixed dispersion liquid, wherein the mass ratio of the graphene to the Mxene is 1: 1-5: 1, the acrylic monomer accounts for 60% -90% of the total mass of the graphene and the Mxene, and the initiator accounts for 2% -10% of the total mass of the acrylic monomer, the graphene and the Mxene;

(3) and (3) adding polyvinyl alcohol into the graphene/Mxene mixed dispersion liquid obtained in the step (2), and carrying out wet spinning on the obtained ternary composite spinning solution to obtain the polyvinyl alcohol-based fiber material for electromagnetic shielding, wherein the total mass of the graphene and the Mxene accounts for 2.5-5% of the mass of the polyvinyl alcohol.

3. The method according to claim 2, wherein the etchant in step (1) is a mixed solution of hydrochloric acid and lithium fluoride, Ti₃AlC₂The mass ratio of the hydrochloric acid to the lithium fluoride is 0.98: 1-1: 1, the concentration of the hydrochloric acid is 5-7 mol/L, and the bath ratio is 1: 25-35.

4. The method according to claim 2, wherein in the step (1), the etching temperature is 20-50 ℃, and the etching time is 24-48 h; the ultrasonic time is 20-60 min, and the ultrasonic power is 10-35W.

5. The method of claim 2, wherein the polyvinyl alcohol in step (1) is PVA-1799; the mass percentage concentration of the polyvinyl alcohol in the dispersion liquid containing the polyvinyl alcohol is 0.4-0.6%.

6. The method of claim 2, wherein the initiator in the step (2) is ammonium persulfate.

7. The method according to claim 2, wherein the temperature of the copolymerization reaction in the step (2) is 70-85 ℃ and the time of the copolymerization reaction is 3-6 h.

8. The method according to claim 2, wherein the volume concentration of the polyvinyl alcohol in the ternary composite spinning solution in the step (3) is 0.11g/ml to 0.14 g/ml; the coagulating bath used for wet spinning forming is saturated sodium sulfate, the temperature of the coagulating bath is 25 +/-2 ℃, and the drawing ratio of a spinning nozzle is 0.05-0.25.

9. The polyvinyl alcohol-based electromagnetic shielding fiber material prepared by the method of claim 2.

10. Use of a fibrous material according to claim 1.

Technical Field

The invention belongs to the field of functional fibers and preparation thereof, and particularly relates to a polyvinyl alcohol-based fiber material for electromagnetic shielding and a preparation method thereof.

Background

With the popularization of electronic products, the influence of electromagnetic radiation on the production and life of people is increasingly serious, the electromagnetic radiation is listed as a fourth environmental pollution source after water sources, atmosphere and noise by the world health organization, and becomes an invisible killer which is harmful to the health of people. The long-term reception of electromagnetic radiation can cause the immunity of people to be reduced, the blood pressure to be abnormal, the metabolism disorder and the memory decline even to cause cancers and the like, so the development of fabrics and clothing products with excellent electromagnetic shielding performance is very important. The research on the electromagnetic shielding fiber and the fabric is mainly prepared by mixing and weaving metal fibers and metal fibers with traditional chemical fibers, the obtained product has poor comfort and hand feeling, and compared with the high-molecular-base flexible conductive fiber, the electromagnetic shielding fiber has good electromagnetic shielding performance and good flexibility, can be used for preparing clothes and fabric products with various shapes and colors by a textile technology, and has wide market development space and application prospect.

Chinese patent CN110563966A discloses a preparation method of MXene/graphene/polyvinyl alcohol composite gel. Mixing MXene dispersion liquid and graphene oxide dispersion liquid, and carrying out hydrothermal reaction to obtain MXene/graphene composite gel; and then, dipping the MXene/graphene composite gel in a polyvinyl alcohol solution to form intermolecular hydrogen bonds, and then circularly freezing and thawing for a plurality of times to obtain the MXene/graphene/polyvinyl alcohol composite gel with controllable structure and better electrochemical performance. Compared with the patent of the invention, the stable co-dispersion solution of graphene/Mxene is realized through an in-situ polymerization mode, and meanwhile, the polyvinyl alcohol/graphene/Mxene composite fiber is prepared through subsequent spinning.

Disclosure of Invention

The invention aims to solve the technical problem of providing a polyvinyl alcohol-based fiber material for electromagnetic shielding and a preparation method thereof, so as to fill the blank in the prior art.

The invention provides a polyvinyl alcohol-based fiber material for electromagnetic shielding, which is prepared by adding graphene into Mxene centrifugate, stirring, adding an acrylic monomer and an initiator, carrying out copolymerization reaction, then adding polyvinyl alcohol, and carrying out wet spinning.

The invention also provides a preparation method of the polyvinyl alcohol-based fiber material for electromagnetic shielding, which comprises the following steps:

(1) mixing Ti₃AlC₂Adding the mixture into an etching agent for etching, carrying out suction filtration and water washing, placing the obtained multilayer expanded Mxene into a dispersion liquid containing polyvinyl alcohol, carrying out ultrasonic stripping to obtain an Mxene dispersion liquid, and centrifuging to obtain a supernatant;

(2) adding graphene into the Mxene centrifugate obtained in the step (1), stirring, adding an acrylic monomer and an initiator, and carrying out copolymerization reaction to obtain a graphene/Mxene mixed dispersion liquid, wherein the mass ratio of the graphene to the Mxene is 1: 1-5: 1, the acrylic monomer accounts for 60% -90% of the total mass of the graphene and the Mxene, and the dosage of the initiator accounts for 2% -10% of the total mass of the acrylic monomer, the graphene and the Mxene;

(3) and (3) adding polyvinyl alcohol into the graphene/Mxene mixed dispersion liquid obtained in the step (2), and carrying out wet spinning on the obtained ternary composite spinning liquid to obtain the polyvinyl alcohol-based fiber material for electromagnetic shielding, wherein the total mass of the graphene and the Mxene accounts for 2.5-5% of the mass of the polyvinyl alcohol.

The etching agent in the step (1) is a mixed solution of hydrochloric acid and lithium fluoride, Ti₃AlC₂The mass ratio of the hydrochloric acid to the lithium fluoride is 0.98: 1-1: 1, the concentration of the hydrochloric acid is 5-7 mol/L, and the bath ratio is 1: 25-1: 35.

In the step (1), the etching temperature is 20-50 ℃, and the etching time is 24-48 h.

In the step (1), the ultrasonic time is 20-60 min, and the ultrasonic power is 10-35W.

The polyvinyl alcohol in the step (1) is PVA-1799.

The mass percentage concentration of the polyvinyl alcohol in the dispersion liquid containing the polyvinyl alcohol in the step (1) is 0.4-0.6%.

And (2) the suction filtration in the step (1) is reduced pressure suction filtration.

And (2) the centrifugal rotating speed in the step (1) is 4500-6000 RPM.

And (3) in the step (2), the initiator is ammonium persulfate.

The temperature of the copolymerization reaction in the step (2) is 70-85 ℃, and the time of the copolymerization reaction is 3-6 h.

The volume concentration of the polyvinyl alcohol in the ternary composite spinning solution in the step (3) is 0.11 g/ml-0.14 g/ml.

And (3) in the step (3), the coagulation bath used for wet spinning is saturated sodium sulfate, the temperature of the coagulation bath is 25 +/-2 ℃, and the drawing ratio of a spinning nozzle is 0.05-0.25.

The invention also provides the polyvinyl alcohol-based electromagnetic shielding fiber material prepared by the method.

The invention also provides application of the polyvinyl alcohol-based fiber material for electromagnetic shielding.

According to the invention, a transition metal nano material Mxene with excellent electromagnetic shielding performance and graphene with excellent conductivity are used as functional fillers, and the uniform co-dispersion of the graphene/Mxene in a water phase is realized by using monomer micromolecules in an in-situ copolymerization mode, so that the phenomena of nonuniform and unstable dispersion of the graphene and the Mxene in a spinning solution are solved. The ternary composite fiber with excellent electromagnetic shielding performance is prepared by compounding with PVA-2099 by means of a wet spinning technology and is widely applied to preparation of various electromagnetic shielding fabrics and clothing products.

Advantageous effects

The invention can realize the uniform dispersion of graphene and Mxene in a polymer matrix, solves the problem of poor spinnability of spinning, and the prepared fiber material has excellent electromagnetic shielding performance.

Drawings

Fig. 1 is a photograph showing the sedimentation delamination of the graphene/Mxene co-dispersion (a) and the Mxene dispersion (b) prepared in example 1 after standing for one week.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

The titanium aluminum carbide raw material is purchased from scientific and technological limited company of Jilin province, the hydrochloric acid, the lithium fluoride, the acrylic acid and the ammonium persulfate are purchased from Chinese medicine reagents, the polyvinyl alcohol 2099 is purchased from Anhui vitamin, and the graphene is purchased from Heizhou sixth element.