阅读说明：本技术 一种高强度高导电性聚乙烯醇/石墨烯复合纤维的制备 (Preparation of high-strength high-conductivity polyvinyl alcohol/graphene composite fiber ) 是由 朱美芳 杨利军 相恒学 费翔 于 2020-06-12 设计创作，主要内容包括：本发明涉及一种高强度高导电性聚乙烯醇/石墨烯复合纤维的制备方法。该方法包括：纺丝液制备；聚乙烯醇/石墨烯初生复合纤维制备,聚乙烯醇/石墨烯复合纤维制备。该方法实现了高电导率聚乙烯醇/石墨烯复合纤维的连续化制备,制备得到的复合纤维具有高电导率和高强度。(The invention relates to a preparation method of a high-strength high-conductivity polyvinyl alcohol/graphene composite fiber. The method comprises the following steps: preparing a spinning solution; preparing polyvinyl alcohol/graphene nascent composite fibers, and preparing polyvinyl alcohol/graphene composite fibers. The method realizes the continuous preparation of the high-conductivity polyvinyl alcohol/graphene composite fiber, and the prepared composite fiber has high conductivity and high strength.)

1. A preparation method of polyvinyl alcohol/graphene composite fibers comprises the following steps:

(1) mixing the graphene dispersion liquid, PEDOT (polyethylene glycol oxide), namely PSS (Polyacrylonitrile) dispersion liquid, polyvinyl alcohol and water, defoaming, and standing to obtain a spinning solution, wherein the spinning solution comprises the following components in percentage by mass: 12-15% of polyvinyl alcohol, 1-4% of graphene, 1-4% of PEDOT, namely PSS, and 77-86% of water;

(2) extruding the spinning solution obtained in the step (1) from a spinneret plate, allowing the obtained nascent fiber to enter a first cross-linking coagulation bath, performing cross-linking coagulation, then entering a second coagulation bath for coagulation, then entering an acidolysis drafting bath for drafting, and then performing immersion bath, water washing bath, drying and winding to obtain a polyvinyl alcohol/graphene nascent composite fiber;

(3) and (3) carrying out constant-temperature crystallization on the polyvinyl alcohol/graphene nascent composite fiber in the step (2) on a constant-temperature hot pair roller by using a fiber post-processing all-in-one machine, then carrying out dry-hot drawing on the hot pair roller, and then carrying out relaxation heat setting and winding to obtain the polyvinyl alcohol/graphene composite fiber.

2. The method according to claim 1, wherein the graphene dispersion liquid in the step (1) has a mass percentage concentration of 0.8-1.5%; the mass percentage concentration of the PEDOT and PSS dispersion liquid is 1-2 wt%; the polyvinyl alcohol is PVA-2099.

3. The method of claim 1, wherein the diameter of the spinneret hole in step (2) is 0.1-0.2 mm; the extrusion speed is 5-10 m/min.

4. The method as claimed in claim 1, wherein in the step (2), the first crosslinking coagulation bath comprises the following components in percentage by mass: 25-30% Na₂SO₄，0.5-1％NaOH，69-74.5％H₂O; the components of the second coagulating bath are as follows: na with the mass percentage concentration of 25-30%₂SO₄An aqueous solution.

5. The method according to claim 1, wherein the temperature of the first crosslinking coagulation bath in the step (2) is 25-45 ℃; the temperature of the second coagulation bath is 35-45 ℃; the draft multiple is 1-2 times.

6. The method as claimed in claim 1, wherein the acidolysis drawing bath in the step (2) comprises the following components in percentage by mass: 25-27% Na₂SO₄，1-5％HCl，68-74％H₂O; the soaking bath comprises the following components in percentage by mass: 70-80% DMSO, 20-30% H₂O; the water bath was standard industrial tap water.

7. The method as claimed in claim 1, wherein the acid hydrolysis drawing bath temperature in the step (2) is 85-95 ℃; the temperature of the soaking bath is 45-55 ℃; the water bath temperature is room temperature.

8. The method as claimed in claim 1, wherein the constant temperature hot-rolling temperature in the step (3) is 190 ℃ to 210 ℃; the constant temperature crystallization time is 10-70s, and the hot-roller dry heat drafting multiple is 1-4 times; the shrinkage rate of the relaxation heat setting is controlled to be 0.1-1%.

9. A polyvinyl alcohol/graphene composite fiber prepared by the method of claim 1.

10. Use of the polyvinyl alcohol/graphene composite fiber prepared by the method according to claim 1.

Technical Field

The invention belongs to the field of preparation of conductive composite materials, and particularly relates to a preparation method of a high-strength high-conductivity polyvinyl alcohol/graphene composite fiber.

Background

Graphene is a two-dimensional lamellar material composed of single atoms, and has excellent electric conduction and heat conduction properties. The composite filled conductive fiber material using graphene as conductive filler is widely researched and reported. However, the conductivity of the obtained conductive fiber is not high, and the bottleneck problems are mainly poor dispersibility and low addition concentration. Although the addition concentration is slightly improved after the treatment by adopting a chemical modification method, an in-situ polymerization method and the like, the addition concentration is far lower than that of the carbon black conductive composite material (about 40 percent). And the original SP of the modified graphene₂The hybrid structure is destroyed and the intrinsic conductivity properties are lost significantly. After graphene (added with a surfactant and the like) is treated by a physical method, although the addition amount is increased, the conductivity of a matrix is influenced by the residue of the dispersion stabilizer, and meanwhile, the way of improving the addition amount by a pure physical method enables the mechanical property of the material to become brittle, the modulus to be greatly increased, the wearability and the weavability of the fiber to be influenced, and the problem of pain in the industry is that the preparation of the high-strength, high-conductivity and high-flexibility polymer/graphene composite fiber is caused.

Disclosure of Invention

The invention aims to solve the technical problem of providing a preparation method of a high-strength high-conductivity polyvinyl alcohol/graphene composite fiber, so as to overcome the defect of low conductivity of a graphene conductive fiber in the prior art.

The invention provides a preparation method of polyvinyl alcohol/graphene composite fibers, which comprises the following steps:

(1) mixing the graphene dispersion liquid, PEDOT (polyethylene glycol oxide), namely PSS (Polyacrylonitrile) dispersion liquid, polyvinyl alcohol and water, defoaming, and standing to obtain a spinning solution, wherein the spinning solution comprises the following components in percentage by mass: 12-15% of polyvinyl alcohol, 1-4% of graphene, 1-4% of PEDOT, namely PSS, and 77-86% of water;

(2) extruding the spinning solution obtained in the step (1) from a spinneret plate, allowing the obtained nascent fiber to enter a first cross-linking coagulation bath, performing cross-linking coagulation, then entering a second coagulation bath for coagulation, then entering an acidolysis drafting bath for drafting, and then performing immersion bath, water washing bath, drying and winding to obtain a polyvinyl alcohol/graphene nascent composite fiber;

(3) and (3) carrying out constant-temperature crystallization on the polyvinyl alcohol/graphene nascent composite fiber in the step (2) on a constant-temperature hot roller pair by utilizing a fiber post-processing all-in-one machine to expand and grow the microcrystal, then carrying out dry-hot drawing on the hot roller pair to enable the molecular chain and the microcrystal orientation to induce the graphene sheet layer to be directionally arranged along an external force to construct a conductive network, and then relaxing and heat setting to eliminate internal stress and winding to obtain the polyvinyl alcohol/graphene composite fiber.

The mass percentage concentration of the graphene dispersion liquid in the step (1) is 0.8-1.5%. The graphene dispersion liquid is a water phase system.

In the step (1), the mass percentage concentration of the PEDOT to PSS dispersion liquid is 1-2 wt%; the polyvinyl alcohol is PVA-2099.

And (2) defoaming in the step (1) is carried out at normal temperature and under reduced pressure.

The aperture of the spinneret plate in the step (2) is 0.1-0.2mm, and preferably 0.15 mm.

The extrusion speed in the step (2) is 5-10 m/min.

The first crosslinking coagulation bath in the step (2) comprises the following components in percentage by mass: 25-30% Na₂SO₄，0.5-1％NaOH，69-74.5％H₂O。

The components of the second coagulating bath in the step (2) are as follows: na with the mass percentage concentration of 25-30%₂SO₄An aqueous solution.

The temperature of the first cross-linking coagulation bath in the step (2) is 25-45 ℃.

The temperature of the second coagulation bath in the step (2) is 35-45 ℃; the draft multiple is 1-2 times.

The acidolysis drafting bath in the step (2) comprises the following components in percentage by mass: 25-27% Na₂SO₄，1-5％HCl，68-74％H₂O。

The immersion bath in the step (2) comprises the following components in percentage by mass: 70-80% DMSO, 20-30% H₂O。

And (3) the water bath in the step (2) is standard industrial tap water.

The temperature of the acidolysis drafting bath in the step (2) is 85-95 ℃.

The temperature of the immersion bath in the step (2) is 45-55 ℃, and the temperature of the water bath is room temperature.

The drying in the step (2) comprises the following steps: drying with hot air at 220 deg.C for 2 m.

The fiber post-processing integrated machine in the step (2) is wet spinning multifunctional post-processing integrated equipment disclosed by Chinese patent CN107687029A, the equipment comprises an integrated floor type rack, and a drying area, a drafting area and a shaping area are sequentially arranged on the rack from left to right; a tension frame and a yarn inlet channel are arranged on the left side wall of the drying area, a first channel is arranged on the side wall of the drying area adjacent to the drafting area, a second channel is arranged on the side wall of the drafting area adjacent to the shaping area, and a yarn outlet channel and an upper oiling wheel are arranged on the right side wall of the shaping area; the continuous two-stage tension cohesion drafting mode is arranged in the drafting zone, the drafting rollers are arranged in an isosceles triangle and are designed into a 2-3-2 combined structure, the two groups of stepped 0.4-0.45m long pair roller combined shaping mode are arranged in the shaping zone, and the drafting rollers are arranged in a stepped field shape.

The temperature of the constant-temperature hot roller pair in the step (3) is 190-210 ℃; the constant temperature crystallization time is 10-70 s.

The hot pair roller dry heat drafting multiple in the step (3) is 1-4 times; the shrinkage rate of the relaxation heat setting is controlled to be 0.1-1%.

The invention also provides the polyvinyl alcohol/graphene composite fiber prepared by the method.

The invention also provides an application of the polyvinyl alcohol/graphene composite fiber prepared by the method.

The invention realizes the continuous preparation of the composite fiber by utilizing a spinning technology of fractional solidification and multistage drafting (which is beneficial to the regulation and control of fiber micropores, a microfiber structure and a fiber skin-core structure and ensures that a stock solution trickle is quickly solidified into nascent fiber), and simultaneously realizes the preparation of the polyvinyl alcohol/graphene high-conductivity composite fiber by jointly constructing a conductive network in the fiber by utilizing the expansion and orientation of microcrystals in the fiber.

According to the invention, the polyvinyl alcohol/graphene composite fiber with high conductivity and high strength is continuously prepared by compounding graphene as a conductive modifier, an auxiliary conductive polymer as a conductive reinforcing agent and polyvinyl alcohol through a wet spinning technology by using Chinese-style large-scale equipment. According to the invention, through the design of a formula and a fiber forming process, microcrystals in the fiber are expanded and grown in the post-processing process and are oriented along the direction of an external force, and a conductive network in the fiber is constructed by the oriented graphene sheet layers, so that the monofilament conductivity of the fiber reaches 33.6s/m, the mechanical strength is 3.16-4.82cN/dtex, and the industrial textile requirements are met. The fiber downstream product has wide application in the fields of military electromagnetic shielding, civil electrostatic protection, intelligent clothing, wearable equipment and the like.

Advantageous effects

(1) The invention realizes the continuous preparation of the high-conductivity polyvinyl alcohol/graphene composite fiber, and the conductivity of the single fiber of the fiber is as high as 33.6S/m.

(2) The invention realizes high conductivity and high strength of the fiber, and the mechanical strength is 3.16-4.82 cN/dtex.

Drawings

Fig. 1(a) is a drawing of a filament of a polyvinyl alcohol/graphene conductive fiber prepared in a formula scale according to the present invention, (b) is a drawing of a conductivity of a polyvinyl alcohol/graphene conductive fiber fabric according to the present invention, and (c) is an optical photograph of a polyvinyl alcohol/graphene conductive fiber yarn according to the present invention.

Fig. 2 is a graph of the conductivity of the polyvinyl alcohol/graphene composite fiber prepared in example 1.

FIG. 3 is a schematic structural view of the fiber post-processing integrated machine of the present invention.

FIG. 4 is a cross-sectional view of the draft zone of the fiber finishing assembly of the present invention.

In the figure: 1. tension frame, 2 drying zone, 3 drafting zone, 4 sizing zone, 5 lifting door, 6 air outlet, 7 oil feeding wheel, 8 air inlet, 9 humidifier, 10 godet roller, 11 drafting roller, 12 sizing roller, 13 lifting door power motor, 14 balance weight, 15 fan, 16 heater, 17 lifting door guide wheel.

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.

Polyvinyl alcohol is purchased from Anhui vitamin, graphene is purchased from Heizhou sixth element, and other chemical reagents are purchased from national medicine reagents.