Highly elastic sensing core yarn and method of making same

Abstract

The application discloses a kind of high-elasticity sensing core yarn and preparation method thereof, belong to intelligent textile preparation technical field, including the following steps: step S1, composite elastic fiber is placed in conductive nanodispersion and is immersed and treated, and modified conductive fiber is obtained;Step S2, modified conductive fiber is added to polyurethane solution, after 30-50min of immersion treatment, dry at 60 DEG C condition, then after opening, carding, twisting, obtain high-elasticity sensing core yarn.The application introduces the modified carbon nanotube dispersion liquid with good dispersibility, effectively avoids the agglomeration phenomenon of modified carbon nanotube during composite elastic fiber immersion, gives the good sensing performance of elastic core yarn, at the same time, the intramolecular structure of the composite elastic fiber of the application contains polyaniline with good electrochemical performance, forms internal and external conductive path in elastic core yarn, further enhances the sensing performance of elastic core yarn.

Description

Technical Field

[0001] This invention belongs to the field of intelligent textile manufacturing technology, specifically relating to a highly elastic sensing core yarn and its preparation method. Background Technology

[0002] High-elasticity sensing core yarn is a type of yarn composed of a high-elasticity polymer as a base and conductive filler. Its main purpose is to serve as the core sensing element of smart textiles for real-time monitoring of human physiological parameters such as heart rate, blood oxygen saturation, and respiratory rate. It is widely used in fields such as medical health, sports and fitness, and smart homes.

[0003] In existing technologies, carbon nanotubes are usually added as sensing fillers when preparing highly elastic sensing core yarns. Carbon nanotubes have good electrical conductivity, which can give the yarn excellent sensing properties. However, the surface of carbon nanotubes lacks active functional groups and has poor dispersion performance. They are prone to agglomeration in solvents, which limits their application in core yarn sensing. Therefore, how to improve the dispersion performance of carbon nanotubes without damaging their electrical conductivity is a technical problem that needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a highly elastic sensing core yarn and its preparation method to solve the problems in the background art.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for preparing a highly elastic sensing core yarn includes the following steps:

[0007] Step S1: Preparation of conductive fibers:

[0008] Composite elastic fibers were added to the modified carbon nanotube dispersion and ultrasonically reacted at room temperature for 10-15 minutes. After drying, the mixture was placed in the silver nanowire dispersion and ultrasonically reacted for another 10-15 minutes. After drying, the modified conductive fibers were obtained.

[0009] Step S2, Synthesis of high-elasticity sensing core yarn:

[0010] Modified conductive fibers are added to a polyurethane solution, impregnated for 30-50 minutes, dried at 60°C, and then opened, combed, and twisted to obtain a highly elastic sensing core yarn.

[0011] Further, in step S1, the ratio of modified carbon nanotube dispersion, composite elastic fiber, and silver nanowire dispersion is 80 mL: 15-20 g: 60 mL; the concentration of the silver nanowire dispersion is 0.9-1.3 wt%. In step S2, the ratio of polyurethane solution and modified conductive fiber is 80 mL: 10-12 g; the concentration of the polyurethane solution is 0.4-0.6 wt%.

[0012] Furthermore, the modified carbon nanotube dispersion is obtained by dispersing multi-walled carbon nanotubes, sericin and dodecylbenzenesulfonic acid in deionized water and then sonicating for 40 minutes.

[0013] In this process, sericin is used as a surface modifier. With the assistance of the small molecule surfactant dodecylbenzenesulfonic acid, the aromatic groups in sericin are bonded to multi-walled carbon nanotubes through π-π non-covalent bonds, resulting in modified carbon nanotubes with sericin-modified surfaces. Compared with covalent modification by grafting active functional groups onto the surface of multi-walled carbon nanotubes, non-covalent modification can not only improve the dispersibility of multi-walled carbon nanotubes, but also does not destroy the crystal structure of multi-walled carbon nanotubes, thus not reducing the conductivity of multi-walled carbon nanotubes.

[0014] Furthermore, the ratio of the multi-walled carbon nanotubes, sericin, dodecylbenzenesulfonic acid, and deionized water is 3-5g: 0.6-1g: 0.02-0.1g: 100mL.

[0015] Furthermore, the composite elastic fiber is prepared by the following steps:

[0016] A1. Add citric acid and ammonium persulfate to deionized water, disperse by ultrasonication, add dichloromethane and bio-based elastomer, stir and mix at 1-5℃, then add aniline solution, continue stirring and reacting for 3-4 hours, and then filter, wash and dry to obtain conductive elastomer.

[0017] A2. Vacuum-dried spandex resin and conductive elastomer are mixed evenly in a mixer, then melt-spun, and after traction and winding, composite elastic fibers are obtained.

[0018] Among them, ammonium persulfate is used as an initiator and citric acid is used as a crosslinking agent. Polyaniline is synthesized on the molecular chain of bio-based elastomer by in-situ emulsion polymerization. Polyaniline has special electrochemical properties. After doping, a conductive elastomer is obtained, which is then covalently bonded with spandex resin to obtain a composite elastic fiber with intrinsic conductive properties.

[0019] The composite elastic fiber of the present invention

[0020] Furthermore, in step A1, the ratio of deionized water, citric acid, ammonium persulfate, dichloromethane, bio-based elastomer, and aniline solution is 50mL: 6.2-8.1g: 3.6-4.3g: 40mL: 5-7g: 50mL; in step A2, the mass ratio of spandex resin to conductive elastomer is 30-50: 6-9.

[0021] Furthermore, the aniline solution is prepared by dispersing aniline in a polyvinylpyrrolidone solution with a concentration of 13.6-14.5 wt%.

[0022] The volume ratio of aniline to polyvinylpyrrolidone solution is 3-4:60. As a high molecular weight surfactant, polyvinylpyrrolidone has good dispersibility and stability in aqueous solution. It can not only improve the dispersibility of aniline in deionized water, but also prevent aniline from polymerizing prematurely during the preparation of conductive elastomers.

[0023] Furthermore, the bio-based elastomer is prepared through the following steps:

[0024] Hydroxyl-terminated polybutadiene was added to toluene under an argon atmosphere and stirred. Then, 4,4'-diphenylmethane diisocyanate and dibutyltin dilaurate were added, and the mixture was reacted at 40-45℃ for 4-5 hours. The temperature was then raised to 80-90℃ and the reaction was continued for 6-7 hours. Then, lactide and stannous octoate were added, and the mixture was stirred evenly. The mixture was then reacted at 100-110℃ for 10-12 hours. The mixture was then placed in excess anhydrous ethanol to precipitate the product. Finally, the product was filtered, washed, and dried to obtain the bio-based elastomer.

[0025] In this process, hydroxyl-terminated polybutadiene is used as a prepolymer, 4,4'-diphenylmethane diisocyanate is used as a chain extender, and dibutyltin dilaurate is used as a catalyst. Through coupling reaction, macromolecular soft segments containing hydroxyl-terminated segments are obtained. Then, using the macromolecular soft segments as initiators, under the catalysis of stannous octoate, ring-opening polymerization is carried out between the terminal hydroxyl groups and lactide to obtain a block-type bio-based elastomer with polylactic acid as the hard segment.

[0026] Further, the ratio of toluene, hydroxyl-terminated polybutadiene, 4,4'-diphenylmethane diisocyanate, dibutyltin dilaurate, lactide, and stannous octoate is 100mL: 14.1-20.6mL: 1.2-1.6g: 0.1-0.3mL: 16-24g: 0.01-0.03mL.

[0027] A highly elastic sensing core yarn is prepared by the above method.

[0028] The beneficial effects of this invention are:

[0029] The composite elastic fiber of this invention contains active groups such as amino and isocyanate groups on its surface. When impregnated in a modified carbon nanotube dispersion, the modified carbon nanotubes contain sericin, which has bioadhesive properties that allow the modified carbon nanotubes to adhere to the surface of the composite elastic fiber. Stable chemical bonds are formed through the combination of hydroxyl and isocyanate groups, enhancing the intermolecular forces between the composite elastic fiber and the modified carbon nanotubes. At the same time, silver nanowires can be adsorbed onto the surface of the modified carbon nanotubes through electrostatic interactions and work together with them to construct a dense three-dimensional conductive network on the surface of the modified conductive fiber, giving the core yarn excellent conductive sensing performance. In addition, the polyurethane coating treatment of the modified conductive fiber can effectively prevent the oxidation of silver nanowires on the surface of the sensing core yarn, thereby improving the stability of the conductive network. On the other hand, it can also act as an "adhesive," enhancing the interfacial bonding force between the conductive layer and the fiber surface, effectively preventing the conductive layer from falling off, and further improving the conductive sensing performance of the sensing core yarn.

[0030] This invention effectively avoids the aggregation of modified carbon nanotubes during impregnation of composite elastic fibers by introducing a well-dispersible modified carbon nanotube dispersion, ensuring that the modified carbon nanotubes are uniformly and firmly bonded to the surface of the composite elastic fibers. This endows the elastic core yarn with excellent sensing properties. At the same time, the internal molecular structure of the composite elastic fiber of this invention contains polyaniline with good electrochemical properties, which works synergistically with the three-dimensional conductive layer of modified carbon nanotubes and silver nanowires to form internal and external conductive pathways in the elastic core yarn, further enhancing the sensing properties of the elastic core yarn. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a bio-based elastomer, which is prepared through the following steps:

[0034] 14.1 mL of hydroxyl-terminated polybutadiene was added to 100 mL of toluene under an argon atmosphere and stirred. 1.2 g of 4,4'-diphenylmethane diisocyanate and 0.1 mL of dibutyltin dilaurate were added, and the mixture was reacted at 40 °C for 4 h. The temperature was then raised to 80 °C and the reaction was continued for 6 h. 16 g of lactide and 0.01 mL of stannous octoate were added, and the mixture was stirred evenly and reacted at 100 °C for 10 h. The mixture was then placed in excess anhydrous ethanol to precipitate the product. Finally, the product was filtered, washed, and dried to obtain the bio-based elastomer.

[0035] Example 2

[0036] This embodiment provides a bio-based elastomer, which is prepared through the following steps:

[0037] 16.3 mL of hydroxyl-terminated polybutadiene was added to 100 mL of toluene under an argon atmosphere and stirred. 1.4 g of 4,4'-diphenylmethane diisocyanate and 0.2 mL of dibutyltin dilaurate were added, and the mixture was reacted at 43 °C for 4.5 h. The temperature was then raised to 85 °C and the reaction was continued for 6.5 h. 20 g of lactide and 0.02 mL of stannous octoate were added, and the mixture was stirred evenly. The mixture was then reacted at 105 °C for 11 h. The mixture was then placed in excess anhydrous ethanol to precipitate the product. Finally, the product was filtered, washed, and dried to obtain the bio-based elastomer.

[0038] Example 3

[0039] This embodiment provides a bio-based elastomer, which is prepared through the following steps:

[0040] 20.6 mL of hydroxyl-terminated polybutadiene was added to 100 mL of toluene under an argon atmosphere and stirred. 1.6 g of 4,4'-diphenylmethane diisocyanate and 0.3 mL of dibutyltin dilaurate were added, and the mixture was reacted at 45 °C for 5 h. The temperature was then raised to 90 °C and the reaction was continued for 7 h. 24 g of lactide and 0.03 mL of stannous octoate were added, and the mixture was stirred evenly. The mixture was then reacted at 110 °C for 12 h. The mixture was then placed in excess anhydrous ethanol to precipitate the product. Finally, the product was filtered, washed, and dried to obtain the bio-based elastomer.

[0041] Example 4

[0042] This embodiment provides a composite elastic fiber, which is prepared through the following steps:

[0043] A1. Add 3 mL of aniline to 60 mL of a 13.6 wt% polyvinylpyrrolidone solution, mix well, and obtain an aniline solution.

[0044] A2. Add 6.2g of citric acid and 3.6g of ammonium persulfate to 50mL of deionized water, disperse by ultrasonication, add 40mL of dichloromethane and 5g of the bio-based elastomer prepared in Example 1, stir and mix at 1°C, then add 50mL of aniline solution, continue stirring and reacting for 3h, and then filter, wash and dry to obtain conductive elastomer.

[0045] A3. Vacuum-dried 30g of spandex resin and 6g of conductive elastomer are placed in a mixer and mixed evenly. Then, melt spinning is performed, and after traction and winding, composite elastic fibers are obtained.

[0046] Example 5

[0047] This embodiment provides a composite elastic fiber, which is prepared through the following steps:

[0048] A1. Add 3.5 mL of aniline to 60 mL of a 14.1 wt% polyvinylpyrrolidone solution, mix well, and obtain an aniline solution.

[0049] A2. Add 7.2g of citric acid and 3.9g of ammonium persulfate to 50mL of deionized water, disperse by ultrasonication, add 40mL of dichloromethane and 6g of the bio-based elastomer prepared in Example 2, stir and mix at 3°C, then add 50mL of aniline solution, continue stirring and reacting for 3.5h, and then filter, wash and dry to obtain the conductive elastomer.

[0050] A3. Vacuum-dried 40g of spandex resin and 7g of conductive elastomer are placed in a mixer and mixed evenly. Then, melt spinning is performed, and after traction and winding, composite elastic fibers are obtained.

[0051] Example 6

[0052] This embodiment provides a composite elastic fiber, which is prepared through the following steps:

[0053] A1. Add 4 mL of aniline to 60 mL of a 14.5 wt% polyvinylpyrrolidone solution, mix well, and obtain an aniline solution.

[0054] A2. Add 8.1g of citric acid and 4.3g of ammonium persulfate to 50mL of deionized water, disperse by ultrasonication, add 40mL of dichloromethane and 7g of the bio-based elastomer prepared in Example 3, stir and mix at 5°C, then add 50mL of aniline solution, continue stirring and reacting for 4h, and then filter, wash and dry to obtain conductive elastomer.

[0055] A3. Vacuum-dried 50g of spandex resin and 9g of conductive elastomer are placed in a mixer and mixed evenly. Then, melt spinning is performed, and after traction and winding, composite elastic fibers are obtained.

[0056] Comparative Example 1: Compared to Example 5, the difference is that spandex resin was directly melt-spun with bio-based elastomer, while the other raw materials and steps were the same.

[0057] Comparative Example 2: Compared to Example 5, the difference is that spandex resin was directly melt-spun with commercially available styrene elastomer, while the other raw materials and steps were the same.

[0058] Example 7

[0059] This embodiment provides a method for preparing a highly elastic sensing core yarn, including the following steps:

[0060] Step S1: Preparation of modified carbon nanotube dispersion:

[0061] Add 0.02g dodecylbenzenesulfonic acid to 100mL of deionized water, stir and mix, add 3g multi-walled carbon nanotubes and 0.6g sericin, sonicate for 40min, and then modify the carbon nanotube dispersion.

[0062] Step S2, Preparation of conductive fibers:

[0063] Add 15g of the composite elastic fiber prepared in Example 4 to 80mL of modified carbon nanotube dispersion, sonicate at room temperature for 10min, remove and dry, place in 60mL of silver nanowire dispersion with a concentration of 0.9wt%, continue sonication for 10min, remove and dry again to obtain modified conductive fiber.

[0064] Step S3: Synthesis of high-elasticity sensing core yarn:

[0065] 10g of modified conductive fiber was added to 80mL of a 0.4wt% polyurethane solution, impregnated for 30min, dried at 60℃, and then opened, combed, and twisted to obtain a highly elastic sensing core yarn.

[0066] Example 8

[0067] This embodiment provides a method for preparing a highly elastic sensing core yarn, including the following steps:

[0068] Step S1: Preparation of modified carbon nanotube dispersion:

[0069] Add 0.06g dodecylbenzenesulfonic acid to 100mL of deionized water, stir and mix, add 4g multi-walled carbon nanotubes and 0.8g sericin, sonicate for 40min, and then modify the carbon nanotube dispersion.

[0070] Step S2, Preparation of conductive fibers:

[0071] 18g of the composite elastic fiber prepared in Example 5 was added to 80mL of modified carbon nanotube dispersion, and ultrasonically reacted at room temperature for 12min. After drying, it was placed in 60mL of silver nanowire dispersion with a concentration of 1.1wt%, and ultrasonically reacted for another 12min. After drying, the modified conductive fiber was obtained.

[0072] Step S3: Synthesis of high-elasticity sensing core yarn:

[0073] 11g of modified conductive fiber was added to 80mL of a 0.5wt% polyurethane solution, impregnated for 40min, dried at 60℃, and then opened, combed, and twisted to obtain a highly elastic sensing core yarn.

[0074] Example 9

[0075] This embodiment provides a method for preparing a highly elastic sensing core yarn, including the following steps:

[0076] Step S1: Preparation of modified carbon nanotube dispersion:

[0077] Add 0.1g dodecylbenzenesulfonic acid to 100mL of deionized water, stir and mix, add 5g multi-walled carbon nanotubes and 1g sericin, sonicate for 40min, and then modify the carbon nanotube dispersion.

[0078] Step S2, Preparation of conductive fibers:

[0079] Add 20g of the composite elastic fiber prepared in Example 6 to 80mL of modified carbon nanotube dispersion, sonicate at room temperature for 15min, remove and dry, place in 60mL of silver nanowire dispersion with a concentration of 1.3wt%, continue sonication for 15min, remove and dry again to obtain modified conductive fiber.

[0080] Step S3: Synthesis of high-elasticity sensing core yarn:

[0081] 12g of modified conductive fiber was added to 80mL of a 0.6wt% polyurethane solution, impregnated for 50min, dried at 60℃, and then opened, combed, and twisted to obtain a highly elastic sensing core yarn.

[0082] Comparative Example 3: Compared with Example 7, the difference is that the composite elastic fiber prepared by Comparative Example 1 was used, while the other raw materials and steps were the same.

[0083] Comparative Example 4: Compared with Example 7, the difference is that the composite elastic fiber prepared by Comparative Example 2 was used, while the other raw materials and steps were the same.

[0084] Comparative Example 5: Compared with Example 7, the difference is that the modified carbon nanotube dispersion was replaced with an equal amount of carbon nanotube dispersion, while the other raw materials and steps were the same.

[0085] Performance tests were conducted on Examples 7-9 and Comparative Examples 3-5. Stress sensing performance: The strain control device (electronic universal testing machine) and the electrical signal acquisition device (high-precision digital multimeter) were connected to the same computer. The resistance was recorded when the strain range was 150-240 wt%, and the sensitivity was calculated. Elasticity test: The elongation at break of the samples was tested according to FZ / T 50006-2013. The results are shown in Table 1.

[0086] Table 1

[0087]

[0088] As shown in Table 1, the high-elasticity sensing core yarns prepared by modified carbon nanotube dispersion and composite elastic fibers in Examples 7-9 have significantly lower resistance than those in Comparative Examples 3-5, and higher sensitivity than those in Comparative Examples 3-5, exhibiting good sensing performance. Furthermore, the highest elongation at break can reach 763%, demonstrating high elasticity. In addition, compared to Comparative Examples 4 and 5, Example 7 exhibits higher sensing performance and elongation at break, indicating that the high-elasticity sensing core yarn prepared by the synergistic use of modified carbon nanotube dispersion and composite elastic fibers has better elasticity and sensing properties.

[0089] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a highly elastic sensing core yarn, characterized in that, Includes the following steps: Step S1: Preparation of conductive fibers: Multi-walled carbon nanotubes, sericin, and dodecylbenzenesulfonic acid were dispersed in deionized water and then sonicated for 40 min to obtain a modified carbon nanotube dispersion. The ratio of multi-walled carbon nanotubes, sericin, dodecylbenzenesulfonic acid, and deionized water was 3-5 g: 0.6-1 g: 0.02-0.1 g: 100 mL. Composite elastic fibers were added to the modified carbon nanotube dispersion and sonicated at room temperature for 10-15 min. After drying, the mixture was placed in a silver nanowire dispersion and sonicated for another 10-15 min. After drying, the modified conductive fibers were obtained. The composite elastic fiber is prepared by the following steps: A1. Citric acid and ammonium persulfate are added to deionized water and ultrasonically dispersed. Then, dichloromethane and bio-based elastomer are added and stirred at 1-5°C. Aniline solution is then added, and the reaction is continued for 3-4 hours. After filtration, washing, and drying, a conductive elastomer is obtained. The ratio of deionized water, citric acid, ammonium persulfate, dichloromethane, bio-based elastomer, and aniline solution is 50mL:6.2-8.1g:3.6-4.3g:40mL:5-7g:50mL. The aniline solution is prepared by dispersing aniline in a 13.6-14.5wt% polyvinylpyrrolidone solution at a volume ratio of 3-4:

60. A2. Vacuum-dried spandex resin and conductive elastomer are mixed evenly in a mixer, then melt-spun, and after traction and winding, composite elastic fibers are obtained; the mass ratio of spandex resin to conductive elastomer is 30-50:6-9. The bio-based elastomer is prepared through the following steps: Hydroxyl-terminated polybutadiene was added to toluene under an argon atmosphere and stirred. 4,4'-diphenylmethane diisocyanate and dibutyltin dilaurate were then added, and the mixture was reacted at 40-45℃ for 4-5 hours. The temperature was then raised to 80-90℃ and the reaction continued for 6-7 hours. Then, lactide and stannous octoate were added, and the mixture was stirred until homogeneous. The mixture was then reacted at 100-110℃ for 10-12 hours. The mixture was then precipitated in excess anhydrous ethanol. Finally, after filtration, washing, and drying, a bio-based elastomer was obtained. The ratio of toluene, hydroxyl-terminated polybutadiene, 4,4'-diphenylmethane diisocyanate, dibutyltin dilaurate, lactide, and stannous octoate was 100mL: 14.1-20.6mL: 1.2-1.6g: 0.1-0.3mL: 16-24g: 0.01-0.03mL. Step S2, Synthesis of high-elasticity sensing core yarn: Modified conductive fibers are added to a polyurethane solution, impregnated for 30-50 minutes, dried at 60°C, and then opened, combed, and twisted to obtain a highly elastic sensing core yarn.

2. The method for preparing a highly elastic sensing core yarn according to claim 1, characterized in that, In step S1, the ratio of modified carbon nanotube dispersion, composite elastic fiber, and silver nanowire dispersion is 80 mL: 15-20 g: 60 mL; the concentration of the silver nanowire dispersion is 0.9-1.3 wt%. In step S2, the ratio of polyurethane solution and modified conductive fiber is 80 mL: 10-12 g; the concentration of the polyurethane solution is 0.4-0.6 wt%.

3. A highly elastic sensing core yarn, characterized in that, Prepared by the preparation method according to any one of claims 1-2.

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