High-strength knittable conductive hydrophobic polyurethane eutectic gel fiber and preparation method thereof

Abstract

The invention discloses a fiber preparation method of high-strength eutectic gel, and belongs to the field of materials. The eutectic gel is prepared by the following steps: uniformly mixing a hydrophobic eutectic solvent, urethane acrylate, a diluent, a photoinitiator and a small amount of an organic solvent to prepare a pre-polymerization solution, and then carrying out photopolymerization, directional stretching and solvent volatilization. The prepared eutectic gel has the advantages of high mechanical property, simple preparation method and the like. The polyurethane acrylate is added into the hydrophobic eutectic solvent, so that high strength and weather resistance are realized at the same time. The prepared hydrophobic eutectic gel fiber has high underwater electrochemical stability, high tensile strength and electrical conductivity, and has wide application prospects in the fields of human motion detection, instrument correction, flexible conductive clothing and the like.

Description

Technical Field

[0001] The invention relates to a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber and a preparation method thereof, belonging to the technical field of low eutectic solvents and functional polymers. Background Art

[0002] Eutectic gel is a soft material based on eutectic solvent (DES) and polymer network. It has become a kind of flexible ionic conductor material with broad application prospects due to its excellent performance in conductivity, thermal stability, cost-effectiveness, electrochemical stability, environmental friendliness, biosafety and processability. However, at present, thin-film eutectic solvent gel faces the disadvantages of poor air permeability, more prone to fatigue and damage under repeated stretching and bending, and insufficient adaptability in the actual wear process. In contrast, fiber-shaped strain sensors are more popular in wearable devices due to their softness, air permeability, structural adjustability and easy integration. However, the development of fibrous eutectic solvent gel requires that the material has good environmental stability and high mechanical properties that meet the sewing requirements. Although the hydrophobic eutectic solvent gel developed at this stage can achieve good environmental stability and show the potential to be prepared into fibrous strain sensors, its mechanical properties are less than 1MPa, which makes it impossible to be woven or sewn into multifunctional conductive fiber cloth. This will greatly limit the practical application of hydrophobic eutectic solvent gel. Therefore, it is urgent to develop a new hydrophobic low eutectic solvent gel fiber, which is different from the traditional film-like low eutectic solvent gel. Summary of the invention

[0003] In the face of the strong hygroscopic properties and weak mechanical properties of the existing eutectic gel, which makes it difficult to be practical in the field of smart fabrics, the present invention rationally constructs a polyurethane polymer network and selects a hydrophobic low eutectic solvent, designs a polyurethane acrylate network with hierarchical hydrogen bond interactions with the hydrophobic low eutectic solvent, and finally realizes a high mechanical strength and high stability hydrophobic eutectic gel fiber that meets the sewing requirements. By introducing an ester-containing segment (polycaprolactone polymer segment) into the polyurethane acrylate, a strong hydrogen bond interaction can be formed between the hydrophobic low eutectic solvent and the polymer network. This can not only enhance the mechanical properties of the prepared gel fiber, but also inhibit the leakage of the low eutectic solvent during the use of the gel fiber, and improve the stability of the fiber during use. At the same time, the present invention also preferably uses tetrahydrofurfuryl acrylate containing a cyclic ether group as a diluent, and the negatively charged oxygen atoms contained in its chemical structure will be conducive to the formation of hydrogen bond interactions between the hydrophobic low eutectic solvent and the polymer formed therewith, thereby further improving the mechanical properties and long-term use stability of the fiber.

[0004] A high-strength, braidable, conductive, hydrophobic, polyurethane eutectic gel fiber, which is prepared by a photopolymerization method using polyurethane acrylate, a diluent, a photoinitiator, and a hydrophobic low eutectic solvent;

[0005] The polyurethane acrylate is prepared from a soft segment, a hard segment, a chain extender and hydroxyethyl acrylate containing a double bond; the soft segment is polypropylene glycol and polycaprolactone, the hard segment is one of isophorone diisocyanate, dicyclohexylmethane diisocyanate or hexamethylene diisocyanate, the chain extender is butanediol, and the hydroxyethyl acrylate containing a double bond is a photosensitive molecule with a molecular weight of 4000.

[0006] In one embodiment, the polyurethane acrylate is prepared by mixing hexamethylene diisocyanate, polycaprolactone diol, polypropylene glycol and acetone in N 2 The mixture was stirred at 60° C. under an atmosphere, dibutyltin dilaurate was added, the stirring was continued, butanediol was added and stirred, hydroxyethyl acrylate was added to react, and polyurethane acrylate was obtained after the solvent was removed.

[0007] In one embodiment, the hydrophobic deep eutectic solvent is prepared by mixing a hydrogen bond acceptor with a hydrogen bond donor.

[0008] In one embodiment, the photopolymerization method is specifically: polymerizing and curing under ultraviolet light, the intensity of the ultraviolet light is 50mw / cm 2 , the lighting time is 15-45min.

[0009] In one embodiment, the high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber has a diameter of 100-900 μm.

[0010] A second object of the present invention is to provide a method for preparing a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber, the method comprising:

[0011] Step 1, mixing a hydrogen bond acceptor and a hydrogen bond donor in a certain molar ratio, and mixing at 60-80° C. for 0.5-2 hours to prepare a hydrophobic low eutectic solvent;

[0012] Step 2, polyurethane acrylate, diluent, hydrophobic low eutectic solvent, a small amount of organic solvent and photoinitiator are uniformly mixed to obtain eutectic gel prepolymer solution, and then the prepolymer solution is placed in a tubular mold and photopolymerized to obtain a fibrous gel;

[0013] Step 3, the fibrous gel is subjected to directional stretching and placed in an environment to dry to obtain a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber.

[0014] In one embodiment, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor in step 1 is 1:1-1:2; the hydrogen bond acceptor includes one of tetrabutylammonium tetrafluoroborate, tetra-n-octylammonium bromide or tetraethylbistrifluoromethanesulfonimide, and the hydrogen bond donor includes trifluoroacetamide.

[0015] In one embodiment, the mass ratio of the polyurethane acrylate to the diluent is 4:1-1:4, and the mass ratio of the hydrophobic low eutectic solvent to the overall prepolymer liquid is 10%-50%.

[0016] In one embodiment, the initiator includes photoinitiator 2959 or photoinitiator 1173, and the photoinitiator accounts for 0.1%-1% of the mass of the prepolymer solution.

[0017] In one embodiment, the mass ratio of the low eutectic solvent to the whole prepolymer solution is 10%-50%.

[0018] In one embodiment, the mass of the organic solvent accounts for 10% of the mass of the entire prepolymer solution.

[0019] In one embodiment, the photoinitiator accounts for 0.1%-1% of the mass of the prepolymer solution.

[0020] In one embodiment, the directional stretching ratio of the high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber is 0%-200%.

[0021] The present invention also provides application of the high-strength, weavable conductive hydrophobic polyurethane eutectic gel fiber in motion detection.

[0022] Beneficial effects:

[0023] The present invention prepares eutectic gel fiber by photocuring, directional stretching, and solvent drying a prepolymer solution containing a hydrophobic low eutectic solvent, polyurethane acrylate, a diluent, a photoinitiator, and a small amount of organic solvent. The prepared eutectic gel has the advantages of high mechanical properties and a simple preparation method. The present invention adds polyurethane acrylate to the hydrophobic eutectic solvent to achieve high strength and weather resistance at the same time. The high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber prepared by the present invention has high underwater electrochemical stability, high tensile strength, and electrical conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 , digital photo of high-strength, weavable conductive hydrophobic polyurethane eutectic gel fibers.

[0025] Figure 2 , tensile stress-strain curves of high-strength, braidable conductive hydrophobic polyurethane eutectic gel fibers.

[0026] Figure 3, high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber, and its weight and conductivity change over time at different humidity, temperature and underwater.

[0027] Figure 4 , after the fiber is washed in water containing detergent for 30 minutes, the resistance and weight change with the number of washes. DETAILED DESCRIPTION

[0028] The mechanical properties of the prepared eutectic gel can be tested by a universal tensile testing machine, and the performance of the elastomer in motion monitoring can be detected by an electrochemical workstation.

[0029] The present invention is further described below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0030] Example 1

[0031] The preparation process of polyurethane acrylate is as follows:

[0032] S1. Add isophorone diisocyanate (22 g, 100 mmol), polycaprolactone diol (80 g, 40 mmol), polypropylene glycol (20 g, 10 mmol) and acetone (500 mL) into a 1000 mL three-necked flask and heat under N 2 Stir at 60°C for 0.5h under atmosphere. Then, dibutyltin dilaurate (0.1g) was added to the system and stirring was continued for 2h. Butanediol (4.5g, 50mmol) was added to the system and stirring was continued for 2h. After that, hydroxyethyl acrylate (7.0g, 50mmol) was added to the system and the reaction was continued until the absorption peak of the isocyanate group on the infrared spectrum disappeared. Finally, polyurethane acrylate was obtained after removing the solvent.

[0033] The preparation process of a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber is as follows:

[0034] S2. 8.8 g (0.027 mol) of hydrogen bond acceptor tetrabutylammonium tetrafluoroborate and 3.9 g (0.035 mol) of hydrogen bond donor trifluoroacetamide were stirred and reacted at 60° C. for 1 h to obtain a clear and transparent hydrophobic low eutectic solvent.

[0035] S3, prepare eutectic gel prepolymer solution: 8.5g hydrophobic low eutectic solvent, 10g polyurethane acrylate, 32.3mg photoinitiator 2959, 8.0g isobornyl acrylate, 2.0g tetrahydrofurfuryl acrylate and 3.2g acetone solution were shaken and mixed evenly, and the ultraviolet light intensity was 50mw / cm 2 The eutectic gel fibers were photopolymerized for 45 min, stretched to 200% and dried at room temperature for 24 h to obtain high-strength eutectic gel fibers.

[0036] The high-strength, braidable conductive hydrophobic eutectic gel fiber has a diameter of 180 μm.

[0037] Example 2

[0038] The preparation process of polyurethane acrylate is as follows:

[0039] S1. Add isophorone diisocyanate (8.8 g, 40 mmol), polycaprolactone diol (20 g, 10 mmol), polypropylene glycol (20 g, 10 mmol) and acetone (500 mL) into a 1000 mL three-necked flask and heat under N 2 Stir at 60°C for 0.5h under atmosphere. Then, dibutyltin dilaurate (0.1g) was added to the system and stirring was continued for 2h. Butanediol (1.8g, 20mmol) was added to the system and stirring was continued for 2h. After that, hydroxyethyl acrylate (2.8g, 20mmol) was added to the system and the reaction was continued until the absorption peak of the isocyanate group on the infrared spectrum disappeared. Finally, polyurethane acrylate was obtained after removing the solvent.

[0040] The preparation process of a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber is as follows:

[0041] S2. 10.8 g (0.020 mol) of hydrogen bond acceptor tetraoctylammonium bromide and 2.8 g (0.024 mol) of hydrogen bond donor trifluoroacetamide were stirred and reacted at 60° C. for 1 h to obtain a clear and transparent hydrophobic low eutectic solvent.

[0042] S3, prepare eutectic gel prepolymer solution: 8.5g hydrophobic low eutectic solvent, 40g polyurethane acrylate, 32.3mg photoinitiator 2959, 8.0g isobornyl methacrylate, 2.0g tetrahydrofurfuryl acrylate and 6.5g acetone solution were shaken and mixed evenly, and the ultraviolet light intensity was 50mw / cm 2 The eutectic gel fibers were photopolymerized for 45 min and then oriented and stretched to 100% and dried at room temperature for 24 h to obtain high-strength eutectic gel fibers.

[0043] The high-strength, braidable conductive hydrophobic eutectic gel fiber has a diameter of 490 μm.

[0044] Example 3

[0045] The preparation process of polyurethane acrylate is as follows:

[0046] S1. Add dicyclohexylmethane diisocyanate (3.2 g, 12 mmol), polycaprolactone diol (8.0 g, 4 mmol), polypropylene glycol (4.0 g, 2 mmol) and acetone (50 mL) into a 250 mL three-necked flask and stir under N 2Stir at 60°C for 0.5h under atmosphere. Then, dibutyltin dilaurate (0.05g) was added to the system and stirring was continued for 2h. Butanediol (0.54g, 6mmol) was added to the system and stirring was continued for 2h. After that, hydroxyethyl acrylate (0.84g, 6mmol) was added to the system and the reaction was continued until the absorption peak of the isocyanate group on the infrared spectrum disappeared. Finally, polyurethane acrylate was obtained after removing the solvent.

[0047] The preparation process of a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber is as follows:

[0048] S2. 44 g (0.134 mol) of hydrogen bond acceptor tetrabutylammonium tetrafluoroborate and 37 g (0.268 mol) of hydrogen bond donor trifluoroacetamide were stirred and reacted at 60° C. for 1 h to obtain a clear and transparent hydrophobic low eutectic solvent.

[0049] S3, prepare eutectic gel prepolymer solution: 56.5g hydrophobic low eutectic solvent, 10g polyurethane acrylate, 565mg photoinitiator 1173, 32g isobornyl acrylate, 8g tetrahydrofurfuryl methacrylate and 6.5g acetone solution were shaken and mixed evenly, and the ultraviolet light intensity was 50mw / cm 2 The eutectic gel fibers were photopolymerized for 45 min, stretched to 50% and dried at room temperature for 24 h to obtain high-strength eutectic gel fibers.

[0050] The high-strength, braidable conductive hydrophobic eutectic gel fiber has a diameter of 780 μm.

[0051] Example 4

[0052] The preparation process of polyurethane acrylate is as follows:

[0053] S1. Add dicyclohexylmethane diisocyanate (16 g, 60 mmol), polycaprolactone diol (40 g, 20 mmol), polypropylene glycol (20 g, 10 mmol) and acetone (500 mL) into a 1000 mL three-necked flask and heat under N 2 Stir at 60oC for 0.5h under atmosphere. Then, dibutyltin dilaurate (0.1g) was added to the system and stirring was continued for 2h. Butanediol (2.7g, 30mmol) was added to the system and stirring was continued for 2h. After that, hydroxyethyl acrylate (4.2g, 30mmol) was added to the system and the reaction was continued until the absorption peak of the isocyanate group on the infrared spectrum disappeared. Finally, polyurethane acrylate was obtained after removing the solvent.

[0054] The preparation process of a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber is as follows:

[0055] S2. 41 g (0.1 mol) of hydrogen bond acceptor tetraethylbis(trifluoromethanesulfonyl)imide and 20 g (0.18 mol) of hydrogen bond donor trifluoroacetamide were stirred and reacted at 60° C. for 1 h to obtain a clear and transparent hydrophobic low eutectic solvent.

[0056] S3, prepare eutectic gel prepolymer solution: 22.8g hydrophobic low eutectic solvent, 15g polyurethane acrylate, 32.3mg photoinitiator 2959, 6.0g isobornyl methacrylate, 6.0g tetrahydrofurfuryl methacrylate and 6.6g acetone solution were shaken and mixed evenly, and the ultraviolet light intensity was 50mw / cm 2 The eutectic gel fibers were photopolymerized for 15 min under low temperature and then stretched to 0% and dried at room temperature for 24 h to obtain high-strength eutectic gel fibers.

[0057] The high-strength, braidable conductive hydrophobic eutectic gel fiber has a diameter of 900 μm.

[0058] Example 5

[0059] The preparation process of polyurethane acrylate is as follows:

[0060] S1. Add hexamethylene diisocyanate (1.6 g, 10 mmol), polycaprolactone diol (4.0 g, 2 mmol), polypropylene glycol (2.0 g, 1 mmol) and acetone (50 mL) into a 250 mL three-necked flask and heat under N 2 Stir at 60°C for 0.5h under atmosphere. Then, dibutyltin dilaurate (0.05g) was added to the system and stirring was continued for 2h. Butanediol (0.45g, 5mmol) was added to the system and stirring was continued for 2h. After that, hydroxyethyl acrylate (0.70g, 5mmol) was added to the system and the reaction was continued until the absorption peak of the isocyanate group on the infrared spectrum disappeared. Finally, polyurethane acrylate was obtained after removing the solvent.

[0061] The preparation process of a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber is as follows:

[0062] S2. 3.3 g (0.01 mol) of hydrogen bond acceptor tetrabutylammonium tetrafluoroborate and 1.4 g (0.012 mol) of hydrogen bond donor trifluoroacetamide were stirred at 60° C. for 1 h to obtain a clear and transparent hydrophobic low eutectic solvent.

[0063] S3, prepare eutectic gel prepolymer solution: 4g hydrophobic low eutectic solvent, 5g polyurethane acrylate, 86mg photoinitiator 1173, 3g isobornyl acrylate, 10g tetrahydrofurfuryl acrylate and 2.4g acetone solution were shaken and mixed evenly, and the ultraviolet light intensity was 50mw / cm 2The eutectic gel fibers were photopolymerized for 25 min, stretched to 200% and dried at room temperature for 24 h to obtain high-strength eutectic gel fibers.

[0064] The high-strength, braidable conductive hydrophobic eutectic gel fiber has a diameter of 120 μm.

[0065] Example 6

[0066] The preparation process of polyurethane acrylate is as follows:

[0067] S1. Add isophorone diisocyanate (8.8 g, 40 mmol), polycaprolactone diol (20 g, 10 mmol), polypropylene glycol (20 g, 10 mmol) and acetone (500 mL) into a 1000 mL three-necked flask and heat under N 2 Stir at 60°C for 0.5h under atmosphere. Then, dibutyltin dilaurate (0.1g) was added to the system and stirring was continued for 2h. Butanediol (1.8g, 20mmol) was added to the system and stirring was continued for 2h. After that, hydroxyethyl acrylate (2.8g, 20mmol) was added to the system and the reaction was continued until the absorption peak of the isocyanate group on the infrared spectrum disappeared. Finally, polyurethane acrylate was obtained after removing the solvent.

[0068] The preparation process of a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber is as follows:

[0069] S2. 33 g (0.01 mol) of hydrogen bond acceptor tetrabutylammonium tetrafluoroborate and 14 g (0.012 mol) of hydrogen bond donor trifluoroacetamide were stirred and reacted at 60° C. for 1 h to obtain a clear and transparent hydrophobic low eutectic solvent.

[0070] S3, prepare eutectic gel prepolymer solution: 4g hydrophobic low eutectic solvent, 16g polyurethane acrylate, 400mg photoinitiator 2959, 9.7g isobornyl acrylate, 5.4g tetrahydrofurfuryl acrylate and 3.9g acetone solution were shaken and mixed evenly, and the ultraviolet light intensity was 50mw / cm 2 The eutectic gel fibers were photopolymerized for 45 min, stretched to 200% and dried at room temperature for 24 h to obtain high-strength eutectic gel fibers.

[0071] The high-strength, braidable conductive hydrophobic eutectic gel fiber has a diameter of 150 μm.

[0072] Comparative Example 1

[0073] If 1.39 g of choline chloride and 1.24 g of ethylene glycol are stirred and reacted at 60° C. for 1 hour, a conventional low eutectic solvent is obtained, and then polyurethane acrylate, a diluent, a photoinitiator, and an organic solvent are added to obtain a non-clear solution, which is characterized by the solution being stratified.

[0074] Properties: Conventional low eutectic solvents are not compatible with polyurethane acrylates and hydrophobic diluents. This is because conventional hydrophilic low eutectic solvents cannot form stable hydrogen bond interactions with polyurethane acrylates.

[0075] Comparative Example 2

[0076] If 3.32 g of tetrabutylammonium tetrafluoroborate and 1.24 g of ethylene glycol are stirred and reacted at 60°C for 1 hour, a clear low eutectic solvent is obtained, and then polyurethane acrylate, a diluent, a photoinitiator, and an organic solvent are added to obtain a non-clear solution, which is characterized by stratification of the solution.

[0077] Properties: If the hydrogen bond acceptor and other non-limited hydrogen bond donors produce a low eutectic solvent that is not miscible with polyurethane acrylate and hydrophobic diluent.

[0078] Comparative Example 3

[0079] If isophorone diisocyanate (22 g, 100 mmol), polytetrahydrofuran (80 g, 40 mmol), polypropylene glycol (20 g, 10 mmol) and acetone (500 mL) are added into a 1000 mL three-necked flask under N 2 Stir at 60°C under atmosphere for 0.5h. Then, dibutyltin dilaurate (0.1g) was added to the system and stirring was continued for 2h. Butanediol (4.5g, 50mmol) was added to the system and stirring was continued for 2h. After that, hydroxyethyl acrylate (7.0g, 50mmol) was added to the system to obtain polyurethane acrylate. Subsequently, a clear solution was obtained with a diluent, a photoinitiator, and a hydrophobic low eutectic solvent, and photopolymerized for 45min, and then oriented and stretched to a ratio of 200% and dried at room temperature for 24h to obtain eutectic gel fibers. It is characterized in that the mechanical properties of the prepared hydrophobic low eutectic gel fibers are less than 1MPa.

[0080] Properties: If polyurethane acrylate is prepared using non-limited ester-containing segments, it will result in the inability to form strong hydrogen bond interactions between the hydrophobic low eutectic solvent and the polyurethane acrylate, which will in turn cause the prepared gel fiber to have lower mechanical properties and be unweavable.

[0081] Comparative Example 4

[0082] If 3.29g of hydrogen bond acceptor tetrabutylammonium tetrafluoroborate and 4.52g of hydrogen bond donor trifluoroacetamide are stirred and reacted at 60°C for 1 hour, a clear and transparent hydrophobic low eutectic solvent is obtained. Then 0.85g of hydrophobic low eutectic solvent, 10.4mg of ethylene glycol diacrylate, 54mg of photoinitiator 1173, 0.63g of isobornyl methacrylate and 2.12g of tetrahydrofurfuryl acrylate are shaken and mixed evenly, and photopolymerized for 60 minutes to obtain eutectic gel fiber. It is characterized in that the mechanical properties of the prepared hydrophobic low eutectic gel fiber are less than 1MPa.

[0083] Properties: If the specified polyurethane acrylate is not used, the hydrophobic low eutectic solvent cannot form a large amount of hydrogen bond interaction with the polymer network, which leads to the prepared gel fiber having lower mechanical properties and being unweavable.

[0084] Test Case

[0085] 1. The mechanical properties of the high-strength hydrophobic eutectic gel were tested using a tensile universal testing machine for the samples prepared in Examples 1, 2, 3, and 4.

[0086] Results: Through the high-strength eutectic gel fiber preparation method disclosed in the present invention, hydrophobic eutectic gel fibers with different mechanical properties can be prepared, and their maximum breaking strengths are all higher than 1MPa, which is much better than the hydrophobic low eutectic solvent gel disclosed at this stage.

[0087] 2. The sample prepared in Example 2 was placed in deionized water containing 10% by mass of detergent and washed for 30 minutes. Its mass and resistance change were measured using a multimeter and a balance.

[0088] Results: After 50 simulated washings, the quality and electrochemical properties (resistance value) of the high-strength, braidable conductive hydrophobic eutectic gel fiber prepared in Example 2 did not change significantly.

[0089] 3. The sample prepared in Example 1, the prepared polyacrylamide hydrogel containing 20% ​​sodium chloride (solid content 20%), and the purchased gel electrode product were placed in a constant temperature and humidity chamber with different humidity and temperature, and their weight changes at different times were measured by a balance.

[0090] Results: After being placed in different temperature and humidity environments for 48 hours, the hydrophobic eutectic gel fiber prepared in Example 1 has excellent stability, and its quality is basically unchanged, showing excellent environmental stability. However, after being placed in different temperature and humidity environments for 48 hours, the commercial gel and conventional hydrogel have drastic changes in quality and have poor environmental stability.

[0091] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber, characterized in that: The high-strength, braidable, conductive hydrophobic polyurethane eutectic gel fiber is prepared from polyurethane acrylate, a diluent, a photoinitiator and a hydrophobic low eutectic solvent by a photopolymerization method; The polyurethane acrylate is prepared from a soft segment, a hard segment, a chain extender and hydroxyethyl acrylate containing a double bond; the soft segment is polypropylene glycol and polycaprolactone, the hard segment is one of isophorone diisocyanate, dicyclohexylmethane diisocyanate or hexamethylene diisocyanate, the chain extender is butanediol, and the hydroxyethyl acrylate containing a double bond is a photosensitive molecule with a molecular weight of 4000.

2. A high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to claim 1, characterized in that: The photopolymerization method is specifically as follows: polymerizing and curing under ultraviolet light, wherein the intensity of the ultraviolet light is 50 mw / cm 2 , the lighting time is 15-45min.

3. The high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to claim 1, characterized in that: The invention discloses a high-strength, braidable, conductive hydrophobic polyurethane eutectic gel fiber with a diameter of 100-900 μm.

4. A method for preparing a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to any one of claims 1 to 3, characterized in that: The method comprises: Step 1, mixing a hydrogen bond acceptor and a hydrogen bond donor, and mixing at 60-80° C. for 0.5-2 hours to prepare a hydrophobic low eutectic solvent; Step 2, polyurethane acrylate, diluent, hydrophobic low eutectic solvent, organic solvent and photoinitiator are uniformly mixed to obtain eutectic gel prepolymer solution, and then the prepolymer solution is placed in a tubular mold and photopolymerized to obtain a fibrous gel; Step 3, the fibrous gel is subjected to directional stretching and placed in an environment to dry to obtain high-strength, braidable conductive hydrophobic polyurethane eutectic gel fibers.

5. The method for preparing a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to claim 4, characterized in that: In step 1, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1-1:2; the hydrogen bond acceptor includes one of tetrabutylammonium tetrafluoroborate, tetra-n-octylammonium bromide or tetraethylbistrifluoromethanesulfonimide, and the hydrogen bond donor includes trifluoroacetamide.

6. The method for preparing a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to claim 4, characterized in that: The mass ratio of the polyurethane acrylate to the diluent is 4:1-1:4, and the mass ratio of the hydrophobic low eutectic solvent to the overall prepolymer liquid is 10%-50%.

7. The method for preparing a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to claim 4, characterized in that: The initiator includes photoinitiator 2959 or photoinitiator 1173, and the photoinitiator accounts for 0.1%-1% of the mass of the prepolymer solution.

8. The method for preparing a high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to claim 1, characterized in that: The diluent is one or both of isobornyl acrylate and isobornyl methacrylate and one or both of tetrahydrofurfuryl acrylate and tetrahydrofurfuryl methacrylate.

9. Use of the high-strength, braidable conductive hydrophobic polyurethane eutectic gel fiber according to any one of claims 4 to 8 in flexible sensing.

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