A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fiber

Abstract

The present invention belongs to the technical field of the preparation of functional polymer materials, and relates to a continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers. The method is to first immerse polyester fibers in a sodium hydroxide solution, then perform ultrasonic treatment in a warm water bath, and then use an in-situ polymerization device to sequentially immerse the polyester fibers modified by ultrasonic-alkali weight reduction in a mixed solution of sodium dodecyl sulfate, aqueous polyurethane and pyrrole monomer and an aqueous ferric chloride solution, and then perform a drying treatment. After repeatedly immersing in the two solutions and performing the drying treatment, polypyrrole / polyurethane / polyester composite conductive fibers are prepared. By performing ultrasonic-alkali weight reduction modification on the polyester fibers, the present invention improves the adhesion amount and firmness of subsequent conductive polypyrrole. Moreover, the composite conductive fibers prepared by the present invention have excellent electrical conductivity while ensuring the excellent mechanical properties of the polyester fibers, and still have a high conductivity after multiple washings and frictions.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of functional polymer materials, and relates to a continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers. Background Art

[0002] Polypyrrole is a conductive polymer material with excellent corrosion resistance. The conductive fibers developed from it can be used in fields such as sensing, electronic shielding, and tissue engineering. At present, the development of polypyrrole-based conductive fibers is usually carried out by titrating the reaction solution or immersing the fibers and their aggregates in the reaction solution, such as in Document 1 (Dyeing and Finishing, 2023, 49(07): 47-50), Document 2 (Journal of Textile Research, 2022, 43(02): 110-115+139), and Patent CN103643339A. However, these methods are difficult to achieve continuous and stable treatment of conductive fibers.

[0003] To solve the above problems, some researchers have also achieved the continuous preparation of polypyrrole / polyurethane composite fibers through in-situ polymerization, such as in Document 3 (npj Flexible Electronics, 2022, 6(1): 42) and Document 4 (Applied Surface Science, 2023, 610: 155515). However, it has been found that the stability of the conductive layer in the composite fibers prepared is poor, and the wear resistance needs to be improved.

[0004] In the prior art, the development methods of polymer conductive fibers mainly include blending and spinning of conductive materials and polymers or post-treatment of polymer fibers. The latter can endow the fibers with conductivity without reducing the mechanical properties of the fibers. For example, in Document 5 (Journal of Textile Research, 2018, 39(02): 20-25), polyester / polyaniline composite conductive yarn was prepared by in-situ polymerization, but the conductive layer is prone to peeling off. In order to improve the durability of the conductive layer, in Document 6 (Journal of Textile Research, 2019, 40(08): 95-100), polyester fibers were treated by plasma, and then polypyrrole / polyester composite conductive yarn was prepared by impregnation and in-situ polymerization. However, although this method improves the firmness of polypyrrole, there are problems such as low polymerization uniformity, poor continuity, and serious waste of the reaction solution.

[0005] In summary, no path for the continuous and stable preparation of high-durability polypyrrole / polyester conductive fibers has been found in the prior art.

[0006] Therefore, it is of great significance to study a continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers to solve the above problems. Summary of the Invention

[0007] The object of the present invention is to solve the problems existing in the prior art and provide a continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers uses an in-situ polymerization device to successively immerse the polyester fibers modified by ultrasonic-alkali deweighting in a mixed solution of sodium dodecyl sulfate (SDS), waterborne polyurethane (WPU) and pyrrole monomer (Py), and an aqueous ferric chloride solution. Ferric chloride, as an oxidant, can initiate the in-situ polymerization reaction of pyrrole monomer on the surface of polyester fibers, and then drying treatment is carried out. The purpose of the drying treatment is to prevent the fibers from winding and stacking and sticking to each other. After the steps of successively immersing in the two solutions and drying treatment are cycled multiple times, polypyrrole / polyurethane / polyester composite conductive fibers are obtained;

[0010] The ultrasonic-alkali deweighting modification of polyester fibers means immersing the polyester fibers in a sodium hydroxide solution and performing ultrasonic treatment in a water bath.

[0011] The present invention immerses the polyester fibers modified by ultrasonic-alkali deweighting combined modification in the in-situ polymerization reaction solution of polypyrrole added with waterborne polyurethane, and by virtue of the viscoelasticity of polyurethane, realizes the continuous development of high-durability polypyrrole / polyurethane / polyester composite conductive fibers in one step.

[0012] The roughness and hydrophilicity of the fiber surface are improved through ultrasonic-alkali deweighting combined modification treatment, thereby improving the adhesion amount and firmness of the subsequent conductive polypyrrole; among them, the increase in roughness provides more physical and chemical bonding points for the adhesion of conductive polypyrrole, thus increasing the adhesion amount of conductive polypyrrole; the improvement of hydrophilicity indicates that there are more hydrophilic groups, and this group can enhance the hydrogen bond interaction between the fiber and polypyrrole, thereby improving the firmness.

[0013] As a preferred technical solution:

[0014] For the continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers as described above, the weight gain rate of the polypyrrole / polyurethane / polyester composite conductive fibers is 27-52 wt.%.

[0015] For the continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers as described above, the conductivity of the polypyrrole / polyurethane / polyester composite conductive fibers is above 0.94 S / m, the retention rate of conductivity after 50 standard washes (the washing method refers to the method in GB / T3921-2008 standard) is above 90%, and the retention rate of conductivity after 5000 friction actions (the friction method refers to the method in GB / T4802.2-2008 standard) is above 85%.

[0016] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fiber as described above. In the mixed solution of sodium dodecyl sulfate, waterborne polyurethane and pyrrole monomer, the concentration of sodium dodecyl sulfate is 0.4 - 0.8 mol / L, the concentration of waterborne polyurethane is 2 - 5 wt.%, and the concentration of pyrrole monomer is 0.5 - 1.5 mol / L.

[0017] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fiber as described above. The concentration of the aqueous ferric chloride solution is 0.5 - 1.5 mol / L.

[0018] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fiber as described above. The concentration of the sodium hydroxide solution is 50 g / L, and the impregnation bath ratio is 1:50.

[0019] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fiber as described above. The water bath temperature is 60 °C, the ultrasonic power is 300 W, and the ultrasonic time is 3 h. These parameters result in the best hydrophilicity of the polyester fiber under the ultrasonic - alkali weight reduction condition, and have greater advantages for its conductive treatment. Therefore, these fixed parameters are selected in the present invention, but it should not be construed as a limitation of the present invention. Other parameter values can still achieve the purpose of the present invention.

[0020] Beneficial effects:

[0021] (1) In the present invention, the ultrasonic - alkali weight reduction combined modification treatment improves the surface roughness and hydrophilicity of the fiber, thereby increasing the adhesion amount and firmness of the subsequent conductive polypyrrole, so that it still has excellent conductivity after multiple washings and frictions.

[0022] (2) In the present invention, the polyester fiber after ultrasonic - alkali weight reduction combined modification is immersed in the reaction solution of in - situ polymerization of polypyrrole added with waterborne polyurethane, and the continuous development of high - durability polypyrrole / polyurethane / polyester composite conductive fiber is realized by a one - step method; in addition, the polypyrrole / polyurethane / polyester composite conductive fiber prepared in the present invention has excellent conductivity and high durability while ensuring the excellent mechanical properties of the polyester fiber.

[0023] (3) The present invention lays a reliable technical guarantee for the continuous conductive treatment and high - value utilization of hydrophobic chemical fibers, enabling the prepared polypyrrole / polyurethane / polyester composite conductive fiber to be highly valued in fields such as sensing and flexible electronics. Brief description of the drawings

[0024] Figure 1 It is a process flow diagram of the preparation of conductive fiber based on in - situ polymerization method in the present invention;

[0025] Figure 2 The surface morphologies of the polyester fibers after the ultrasonic-alkali weight reduction combined treatment of the present invention, the polypyrrole / polyurethane / polyester composite conductive fibers prepared in Examples 1 to 4 and Comparative Example 2, and the polypyrrole / polyester composite conductive fibers prepared in Comparative Example 1; in the figure, a is the surface morphology of the polyester fibers after the ultrasonic-alkali weight reduction combined treatment, b is the surface morphology of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in Example 1, c is the surface morphology of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in Example 2, d is the surface morphology of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in Example 3, e is the surface morphology of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in Example 4, f is the surface morphology of the polypyrrole / polyester composite conductive fibers prepared in Comparative Example 1, and g is the surface morphology of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in Comparative Example 2;

[0026] Figure 3 This is the conductivity change diagram of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in Examples 1 to 4 and Comparative Examples 1 to 2 of the present invention before and after 50 standard washings; in the figure, before / after washing refers to before / after the composite conductive fibers are washed 50 times. Detailed implementation manners

[0027] The present invention will be further described below in conjunction with specific implementation manners. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0028] The test methods for relevant performance indicators in the following examples and comparative examples are as follows:

[0029] Retention rate of conductivity after 50 standard washings: First, measure the conductivity of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in each example and use the test sample as Sample A. Then, remove the yarn part in the plain polyester woven fabric, and then use Sample A to be embedded in the fabric by sewing. Then, wash the fabric 50 times according to the method in the GB / T 3921-2008 standard as a sample. Finally, remove Sample A from the fabric and measure its conductivity. The retention rate of conductivity after 50 standard washings is obtained by calculating the ratio between the conductivity of Sample A after washing and the conductivity of Sample A before washing.

[0030] Retention rate of conductivity after 5000 friction actions: First, measure the conductivity of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in each example, and use the test sample as sample B. Then, remove the yarn part from the plain polyester woven fabric. Subsequently, embed sample B into the fabric by sewing. Then, refer to the method in the standard of GB / T 4802.2-2008 to friction the fabric 5000 times as a sample. Finally, remove sample B from the fabric and measure its conductivity. The retention rate of conductivity after 5000 friction actions is obtained by calculating the ratio between the conductivity of sample B after friction and the conductivity of sample B before friction.

[0031] Tensile strength of polypyrrole / polyurethane / polyester composite conductive fibers: Refer to the method in the standard of GB / T 14344-2022 to measure the tensile strength of the polypyrrole / polyurethane / polyester composite conductive fibers prepared in each example and comparative example as samples, and calculate the average value after measuring each sample 20 times.

[0032] Example 1

[0033] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers is as follows:

[0034] (1) First, prepare a sodium hydroxide solution with a concentration of 50 g / L in a beaker, and then immerse the polyester fibers (the specification of the polyester fibers is 110 dtex / 36f, the single-filament diameter is 19.35 μm, the moisture regain is 0.45%, and the breaking strength is 4.117 N) washed with the washing solution in the sodium hydroxide solution. Then, put the beaker into a 60°C warm water bath and perform ultrasonic treatment with a constant-temperature ultrasonic cleaner; among them, the liquor ratio of immersion is 1:50, the ultrasonic power is 300 W, and the ultrasonic time is 3 h;

[0035] The linear density of the polyester fibers after ultrasonic-alkali weight reduction modification is 95.29 dtex, the moisture regain is 1.33%, and the breaking strength is 3.41 N. Its surface morphology diagram is as Figure 2 shown in (a) in

[0036] (2) As Figure 1As shown, first, the polyester fibers modified by ultrasonic-alkali weight reduction in step (1) are immersed in a mixed solution of sodium dodecyl sulfate, waterborne polyurethane (manufacturer: Shanghai Macklin Biochemical Co., Ltd., solid content of 45%, CAS: NONE8071, product number: W909580), and pyrrole monomer (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., purity of 99%, CAS: 109-97-7) through a yarn guide wheel (diameter of 1 mm, made of ceramic). Then, it is extruded by a rubber pressure roller, and then passes through the holes of a yarn guide needle (the yarn guide needle is a glass tube with holes, hole diameter of 0.5 mm). Under the action of the yarn guide needle, the polyester fibers pass through along the mouth of the burette, and the ferric chloride aqueous solution in the narrow-mouth burette (caliber of 2 mm) is dropped drop by drop to ensure sufficient contact between the fibers and the ferric chloride solution. Subsequently, it passes through the rubber pressure roller again and enters the yarn storage tank under the action of the conveying device. Finally, it is dried and wound onto a yarn tube. Among them, in the mixed solution of sodium dodecyl sulfate, waterborne polyurethane, and pyrrole monomer, the concentration of sodium dodecyl sulfate is 0.6 mol / L, the concentration of waterborne polyurethane is 5 wt.%, and the concentration of pyrrole monomer is 1 mol / L; the concentration of the ferric chloride aqueous solution is 1.5 mol / L; the winding speed of the yarn is 90 m / h, and the conveying device is a rough leather conveyor belt;

[0037] (3) After repeating the process of step (2) 5 times, polypyrrole / polyurethane / polyester composite conductive fibers are prepared.

[0038] The weight gain rate of the finally prepared polypyrrole / polyurethane / polyester composite conductive fibers is 51.76 wt.%, and its surface morphology diagram is as shown in Figure 2 (b) as shown; the conductivity of the polypyrrole / polyurethane / polyester composite conductive fibers is 1 S / m, the linear density is 144.61 dtex, and the retention rate of conductivity after 50 standard washes is 95% (the change in conductivity before and after 50 standard washes is as shown in Figure 3 ); the retention rate of conductivity after 5000 friction actions is 92%; the strength of the polypyrrole / polyurethane / polyester composite conductive fibers is 4.07 N.

[0039] Comparative Example 1

[0040] A continuous preparation method of polypyrrole / polyester composite conductive fibers is basically the same as that in Example 1, except that: the mixed solution in step (2) is only a mixture of sodium dodecyl sulfate and pyrrole monomer, and waterborne polyurethane is not used.

[0041] The weight gain rate of the finally prepared polypyrrole / polyester composite conductive fibers is 15.42 wt.%, and its surface morphology diagram is as shown in Figure 2As shown in (f); the conductivity of the polypyrrole / polyurethane / polyester composite conductive fiber is 0.91 S / m, the linear density is 109.98 dtex, and the retention rate of conductivity after 50 standard washes is 58.2% (the change in conductivity before and after 50 standard washes is as shown in Figure 3 ); the retention rate of conductivity after 5,000 friction actions is 67%; the strength of the polypyrrole / polyurethane / polyester composite conductive fiber is 3.61 N.

[0042] Comparing Comparative Example 1 with Example 1, it can be seen that the weight gain rate of the polypyrrole / polyester composite conductive fiber prepared in Comparative Example 1 is significantly reduced, and the retention rate of conductivity after washing and friction decreases significantly. This is because the interfacial interaction between the polypyrrole conductive layer and the polyester fiber is weak. During multiple polymerization processes, the polypyrrole that has already polymerized onto the fiber surface is extremely easy to detach from the fiber surface and is also prone to detachment from the fiber surface during washing and friction.

[0043] Comparative Example 2

[0044] A continuous preparation method of a polypyrrole / polyurethane / polyester composite conductive fiber is basically the same as that of Example 1, except that: in step (1), only the polyester fiber is washed with a washing solution and then dried at 60 °C for 10 h and equilibrated for 24 h under standard conditions.

[0045] The weight gain rate of the finally prepared polypyrrole / polyurethane / polyester composite conductive fiber is 30.85 wt.%, and its surface morphology diagram is as shown in Figure 2 As shown in (g); the conductivity of the polypyrrole / polyurethane / polyester composite conductive fiber is 0.9 S / m, the linear density is 143.94 dtex, and the retention rate of conductivity after 50 standard washes is 83.3% (the change in conductivity before and after 50 standard washes is as shown in Figure 3 ); the retention rate of conductivity after 5,000 friction actions is 78%; the strength of the polypyrrole / polyurethane / polyester composite conductive fiber is 4.21 N.

[0046] Comparing Comparative Example 2 with Example 1, it can be seen that the strength of the polypyrrole / polyurethane / polyester composite conductive fiber prepared in Comparative Example 2 is increased, the weight gain rate is decreased, and the retention rate of conductivity after washing and friction decreases significantly. This is because although the initial strength of the polyester fiber without ultrasonic-alkali deweighting treatment remains unchanged, the conductive layer will also increase the strength of the composite fiber, but the surface of the initial polyester fiber will be relatively smooth, resulting in the subsequent adhesion amount and firmness of the conductive polypyrrole. After the polyester fiber in Example 1 is treated by ultrasonic-alkali deweighting, the moisture regain, surface roughness, and hydrophilicity of the polyester fiber are improved, thereby improving the adhesion amount and adhesion fastness of the conductive polypyrrole.

[0047] Example 2

[0048] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fiber is as follows:

[0049] (1) First, prepare a sodium hydroxide solution with a concentration of 50 g / L in a beaker, and then immerse the polyester fiber (the specification of the polyester fiber is 110 dtex / 36f, the monofilament diameter is 19.35 μm, the moisture regain is 0.45%, and the breaking strength is 4.117 N) washed with the washing solution in the sodium hydroxide solution. Then, place the beaker in a 60 °C warm water bath and perform ultrasonic treatment using a constant temperature ultrasonic cleaner; among them, the bath ratio of immersion is 1:50, the ultrasonic power is 300 W, and the ultrasonic time is 3 h;

[0050] The linear density of the polyester fiber after ultrasonic-alkali weight reduction modification is 95.29 dtex, the moisture regain is 1.33%, and the breaking strength is 3.41 N;

[0051] (2) As Figure 1 shown, first immerse the polyester fiber after ultrasonic-alkali weight reduction modification in step (1) into the mixed solution of sodium dodecyl sulfate, waterborne polyurethane (manufacturer: Shanghai Macklin Biochemical Co., Ltd., solid content is 45%, CAS is NONE8071, product number is W909580), and pyrrole monomer (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., purity is 99%, CAS is 109-97-7) through a yarn guide wheel (diameter is 2 mm, material is glass), then extrude it through a rubber pressure roller, and then pass through the holes of a yarn guide needle (the yarn guide needle is a metal tube with holes, the hole diameter is 1 mm). Under the action of the yarn guide needle, the polyester fiber passes through the mouth of the burette funnel, and the ferric chloride aqueous solution in the narrow-mouth burette funnel (the caliber is 3 mm) is dropped drop by drop to ensure full contact between the fiber and the ferric chloride solution. Then, it passes through the rubber pressure roller again and enters the yarn storage tank under the action of the conveying device, and finally undergoes drying treatment and is wound onto a yarn tube; among them, in the mixed solution of sodium dodecyl sulfate, waterborne polyurethane, and pyrrole monomer, the concentration of sodium dodecyl sulfate is 0.4 mol / L, the concentration of waterborne polyurethane is 4 wt.%, and the concentration of pyrrole monomer is 0.5 mol / L; the concentration of the ferric chloride aqueous solution is 0.5 mol / L; the winding speed of the yarn is 30 m / h, and the conveying device is a rough leather conveyor belt;

[0052] (3) Repeat the process of step (2) 5 times to obtain polypyrrole / polyurethane / polyester composite conductive fiber.

[0053] The weight gain rate of the finally obtained polypyrrole / polyurethane / polyester composite conductive fiber is 27.93 wt.%, and its surface morphology diagram is as Figure 2as shown in (c); the conductivity of the polypyrrole / polyurethane / polyester composite conductive fiber is 0.94 S / m, the linear density is 121.9 dtex, and the retention rate of conductivity after 50 standard washes is 92.6% (the change in conductivity before and after 50 standard washes is as Figure 3 shown), and the retention rate of conductivity after 5000 friction actions is 88%; the strength of the polypyrrole / polyurethane / polyester composite conductive fiber is 3.75 N.

[0054] Example 3

[0055] A continuous preparation method of a polypyrrole / polyurethane / polyester composite conductive fiber is as follows:

[0056] (1) First, prepare a sodium hydroxide solution with a concentration of 50 g / L in a beaker, and then immerse the polyester fiber (the specification of the polyester fiber is 110 dtex / 36f, the monofilament diameter is 19.35 μm, the moisture regain is 0.45%, and the breaking strength is 4.117 N) washed with a washing solution in the sodium hydroxide solution. Then, place the beaker in a 60 °C water bath and perform ultrasonic treatment using a constant-temperature ultrasonic cleaner; among them, the bath ratio for immersion is 1:50, the ultrasonic power is 300 W, and the ultrasonic time is 3 h;

[0057] The linear density of the polyester fiber after ultrasonic-alkali weight reduction modification is 95.29 dtex, the moisture regain is 1.33%, and the breaking strength is 3.41 N;

[0058] (2) As Figure 1As shown in the figure, first, the polyester fibers modified by ultrasonic-alkali weight reduction in step (1) are immersed in a mixed solution of sodium dodecyl sulfate, waterborne polyurethane (manufacturer: Shanghai Macklin Biochemical Co., Ltd., solid content 45%, CAS: NONE8071, product number: W909580), and pyrrole monomer (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., purity 99%, CAS: 109-97-7) through a yarn guide wheel (diameter 3 mm, made of glass), then extruded by a rubber roller, and then passed through the holes of a yarn guide needle (the yarn guide needle is a ceramic tube with holes, hole diameter 2 mm). Under the action of the yarn guide needle, the polyester fibers pass through along the mouth of the burette, and the aqueous ferric chloride solution in the narrow-mouth burette (caliber 4 mm) is dripped drop by drop to ensure full contact between the fibers and the ferric chloride solution. Subsequently, it passes through the rubber roller again and enters the yarn storage tank under the action of the conveying device, and finally undergoes drying treatment and is wound onto a yarn tube; among them, in the mixed solution of sodium dodecyl sulfate, waterborne polyurethane, and pyrrole monomer, the concentration of sodium dodecyl sulfate is 0.8 mol / L, the concentration of waterborne polyurethane is 3 wt.%, and the concentration of pyrrole monomer is 1.5 mol / L; the concentration of the aqueous ferric chloride solution is 1 mol / L; the winding speed of the yarn is 60 m / h, and the conveying device is a rough leather conveyor belt;

[0059] (3) After repeating the process of step (2) 5 times, polypyrrole / polyurethane / polyester composite conductive fibers are prepared.

[0060] The weight gain rate of the finally prepared polypyrrole / polyurethane / polyester composite conductive fibers is 44.46 wt.%, and its surface morphology diagram is as shown in Figure 2 (d) in; the conductivity of the polypyrrole / polyurethane / polyester composite conductive fibers is 0.96 S / m, the linear density is 137.61 dtex, and the retention rate of conductivity after 50 standard washes is 91.7% (the change in conductivity before and after 50 standard washes is as shown in Figure 3 (d) in), and the retention rate of conductivity after 5000 friction actions is 87%; the strength of the polypyrrole / polyurethane / polyester composite conductive fibers is 3.91 N.

[0061] Example 4

[0062] A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fibers is as follows:

[0063] (1) First, prepare a sodium hydroxide solution with a concentration of 50 g / L in a beaker. Then, immerse the polyester fiber (with a specification of 110 dtex / 36f, a single-filament diameter of 19.35 μm, a moisture regain of 0.45%, and a breaking strength of 4.117 N) that has been washed with the washing solution in the sodium hydroxide solution. After that, place the beaker in a 60 °C warm water bath and perform ultrasonic treatment using a constant-temperature ultrasonic cleaner. Among them, the bath ratio for immersion is 1:50, the ultrasonic power is 300 W, and the ultrasonic time is 3 h;

[0064] The linear density of the polyester fiber after ultrasonic-alkali weight reduction modification is 95.29 dtex, the moisture regain is 1.33%, and the breaking strength is 3.41 N;

[0065] (2) As Figure 1 shown, first immerse the polyester fiber modified by ultrasonic-alkali weight reduction in step (1) into a mixed solution of sodium dodecyl sulfate, waterborne polyurethane (manufacturer: Shanghai Macklin Biochemical Co., Ltd., solid content of 45%, CAS: NONE8071, product number: W909580), and pyrrole monomer (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., purity of 99%, CAS: 109-97-7) through a yarn guide wheel (with a diameter of 4 mm and a metal material). Then, extrude it through a rubber pressure roller, and then pass through the holes of a yarn guide needle (the yarn guide needle is a metal tube with holes, and the hole diameter is 1 mm). Under the action of the yarn guide needle, the polyester fiber passes through the mouth of a burette funnel, and the aqueous ferric chloride solution in a narrow-mouth burette funnel (with a diameter of 3 mm) is dropped drop by drop to ensure sufficient contact between the fiber and the ferric chloride solution. Subsequently, it passes through the rubber pressure roller again and enters a yarn storage tank under the action of a conveying device, and finally undergoes drying treatment and is wound onto a yarn tube. Among them, in the mixed solution of sodium dodecyl sulfate, waterborne polyurethane, and pyrrole monomer, the concentration of sodium dodecyl sulfate is 0.6 mol / L, the concentration of waterborne polyurethane is 2 wt.%, and the concentration of pyrrole monomer is 1 mol / L; the concentration of the aqueous ferric chloride solution is 1.5 mol / L; the winding speed of the yarn is 120 m / h, and the conveying device is a rough leather conveyor belt;

[0066] (3) After repeating the process of step (2) 5 times, a polypyrrole / polyurethane / polyester composite conductive fiber is prepared. Among them, starting from the second cycle of repeating the immersion of the two solutions, the polyester fiber is the polyester fiber wound onto the yarn tube after the previous immersion.

[0067] The weight gain rate of the finally prepared polypyrrole / polyurethane / polyester composite conductive fiber is 38.39 wt.%, and its surface morphology diagram is as Figure 2as shown in (e); the conductivity of the polypyrrole / polyurethane / polyester composite conductive fiber is 0.95 S / m, the linear density is 131.83 dtex, and the retention rate of conductivity after 50 standard washings is 90.5% (the change in conductivity before and after 50 standard washings is as shown in Figure 3 ); the retention rate of conductivity after 5000 friction actions is 85%; the strength of the polypyrrole / polyurethane / polyester composite conductive fiber is 3.87 N.

Claims

1. A continuous preparation method of polypyrrole / polyurethane / polyester composite conductive fiber, characterized in that: First, the polyester fibers modified by ultrasonic-alkali deweighting are dipped in a mixed solution of sodium dodecyl sulfate, waterborne polyurethane and pyrrole monomer through a ceramic yarn guide wheel, then extruded by a rubber roller, and then the extruded polyester fibers pass through the holes of a yarn guide needle. Under the action of the yarn guide needle, the polyester fibers pass through the mouth of a burette funnel, and the aqueous ferric chloride solution in the burette funnel is dripped drop by drop to ensure sufficient contact between the fibers and the aqueous ferric chloride solution. Subsequently, it passes through the rubber roller again and enters a yarn storage tank under the action of a conveying device, and finally is dried and wound onto a yarn tube; after repeating the whole process many times, polypyrrole / polyurethane / polyester composite conductive fibers are prepared. The ultrasonic-alkali deweighting modification of polyester fibers means that the polyester fibers are impregnated in a sodium hydroxide solution and ultrasonic treatment is carried out in a water bath. The conductivity of the polypyrrole / polyurethane / polyester composite conductive fibers is above 0.94 S / m, the retention rate of conductivity after 50 standard washings is above 90%, and the retention rate of conductivity after 5000 friction actions is above 85%.

2. The continuous preparation method of a polypyrrole / polyurethane / polyester composite conductive fiber according to claim 1, characterized in that, The weight gain rate of the polypyrrole / polyurethane / polyester composite conductive fibers is 27-52 wt.%.

3. The continuous preparation method of a polypyrrole / polyurethane / polyester composite conductive fiber according to claim 1, characterized in that, In the mixed solution of sodium dodecyl sulfate, waterborne polyurethane and pyrrole monomer, the concentration of sodium dodecyl sulfate is 0.4-0.8 mol / L, the concentration of waterborne polyurethane is 2-5 wt.%, and the concentration of pyrrole monomer is 0.5-1.5 mol / L.

4. The continuous preparation method of a polypyrrole / polyurethane / polyester composite conductive fiber according to claim 3, characterized in that, The concentration of the aqueous ferric chloride solution is 0.5-1.5 mol / L.

5. The continuous preparation method of a polypyrrole / polyurethane / polyester composite conductive fiber according to claim 1, characterized in that, The concentration of the sodium hydroxide solution is 50 g / L, and the impregnation bath ratio is 1:

50.

6. The continuous preparation method of a polypyrrole / polyurethane / polyester composite conductive fiber according to claim 1, characterized in that, The water bath temperature is 60 °C, the ultrasonic power is 300 W, and the ultrasonic time is 3 h.

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