Self-healing bi-component elastic fiber material and preparation method thereof

Abstract

The invention provides a self-healing bi-component elastic fiber material and a preparation method thereof. The self-healing bi-component elastic fiber material comprises 5-10 g of a thioether modified polyurethane material, 85-95 g of a polylactic acid material and 5-10 g of an adhesive. A polylactic acid material and a thioether modified polyurethane material are blended, then an adhesive is added, the adhesive is surface-modified silicon dioxide nanoparticles, the two-component elastic fiber material with excellent tensile property, elastic recovery rate and self-healing efficiency is obtained, the mechanical elastic property of fibers is guaranteed, meanwhile, the self-healing performance is achieved, and the self-healing performance of the fibers is improved. The application field of the bi-component elastic fiber is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of fibers and relates to a self-healing two-component elastic fiber material and a preparation method thereof. Background Art

[0002] Inspired by the self-curling structure formed by the bonding of the adjacent and adjacent layers of wool, people have developed parallel bicomponent elastic fibers, which have a permanent three-dimensional spiral curling structure similar to wool fibers. This curling structure is elastic and durable, giving this type of fiber excellent fluffiness and elastic recovery rate.

[0003] Compared with common bicomponent elastic fibers such as PET / PTT fiber, PP / PA6 fiber and PET / PA6 fiber, polylactic acid fiber has specific applications in the fields of medical treatment, clothing products and disposable sanitary products due to its unique biodegradability and environmental protection characteristics. At present, bicomponent elastic fibers based on polylactic acid (PLA) are not common in the market. Therefore, it is particularly important to develop bicomponent elastic fibers based on polylactic acid materials.

[0004] At the same time, in practical applications, bicomponent elastic fibers face the problem of weakened performance when damaged. Inspired by nature, self-healing materials can restore their physical properties after damage. Common self-healing fibers are usually prepared from ion gels, biomaterials, etc., but the large-scale production of self-healing fibers is still limited due to the poor dispersion of self-healing functional bodies and complex manufacturing processes.

[0005] Therefore, how to develop a two-component elastic fiber based on polylactic acid material and a simple preparation method so that the two-component elastic fiber can maintain mechanical elastic properties when damaged while having the ability of self-healing, thereby improving the service life of such materials and broadening the application fields of such materials is an urgent problem to be solved in the present invention. Summary of the invention

[0006] The purpose of the present invention is to provide a self-healing two-component elastic fiber material, which comprises the following raw materials in terms of mass: 5-10g of thioether-modified polyurethane material, 85-95g of polylactic acid material, and 5-10g of adhesive.

[0007] As a further improvement, the raw materials for preparing the adhesive include silicon dioxide nanoparticles, paraffin, triethylamine, a surfactant, a silane coupling agent and a surface treatment agent, and the mass ratio of the silicon dioxide nanoparticles to the paraffin is 1:(5-10).

[0008] As a further improvement, the silane coupling agent comprises one of diethylenetriaminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and γ-mercaptopropyltrimethoxysilane.

[0009] As a further improvement, the preparation steps of the adhesive include:

[0010] S4-1: Add silica nanoparticles and paraffin to an aqueous solution containing a surfactant, heat at 70-90°C for 20-35 min, then stir vigorously at 70-90°C and 10000-20000 rpm with a high-speed stirrer for 1-5 min, cool to room temperature, and post-treat to obtain intermediate 1;

[0011] S4-2: adding intermediate 1 to a methanol solution containing a silane coupling agent, oscillating and dispersing the mixture evenly, stirring the mixture at a constant speed at room temperature for 12-48 hours, and performing post-treatment to obtain intermediate 2;

[0012] S4-3: Add intermediate 2 to a toluene solution containing a surface treatment agent and triethylamine, disperse uniformly by ultrasonication, rapidly stir and reflux for 1-5 hours under nitrogen protection, centrifuge and wash, and vacuum dry at 40-60° C. for 1-5 hours to obtain an adhesive.

[0013] As a further improvement, the preparation step of silica nanoparticles in step S4-1 comprises: vigorously stirring anhydrous ethanol, deionized water and ammonia water in a round-bottom flask for 10-40 minutes, then adding tetraethyl silicate dropwise, stirring and reacting at room temperature for 6-15 hours, filtering, separating and washing to obtain a precipitate, drying at 100-110° C. for 1-5 hours, and grinding through a 90-100 mesh sieve to obtain silica nanoparticles.

[0014] As a further improvement, the raw materials for preparing the thioether-modified polyurethane material include polytetrahydrofuran, isocyanate derivatives, bis(4-hydroxypropyl) disulfide and a catalyst.

[0015] As a further improvement, it is characterized in that the relative molecular mass of the polytetrahydrofuran is 1000-2000, the isocyanate derivative comprises one of 2,4-toluene diisocyanate, isophorone diisocyanate and diphenylmethane-4,4'-diisocyanate, and the catalyst is one of dibutyltin dilaurate and stannous octoate.

[0016] As a further improvement, it is characterized in that the preparation steps of the thioether-modified polyurethane material include:

[0017] S8-1: Add polytetrahydrofuran into a three-necked round-bottom flask, mechanically stir at 90-110°C under vacuum for 0.5-1.5h, then cool to 60-80°C, add N,N-dimethylacetamide solution containing isocyanate derivatives and dibutyltin dilaurate, and stir under argon atmosphere for 1-2h to obtain a mixture A;

[0018] S8-2: Cool mixture A to room temperature, add N,N-dimethylacetamide solution containing bis(4-hydroxyphenyl) disulfide, heat to 40-50° C., and react for 1-2 h to obtain mixture B;

[0019] S8-3: Mix mixture B and N,N-dimethylacetamide to prepare a 10-40wt% N,N-dimethylacetamide solution, then pour it into a mold and heat it for 36-48 hours to prepare a thioether-modified polyurethane material by a hot fiber stretching method.

[0020] The present invention also provides a method for preparing a self-healing two-component elastic fiber material, comprising the following steps: drying each component material at 75-85°C for 4-10 hours, premixing a polylactic acid material and a thioether-modified polyurethane material, then adding an adhesive, blending and granulating in a co-rotating twin-screw extruder, and then obtaining the self-healing two-component elastic fiber material through an injection molding machine.

[0021] As a further improvement, the temperature of the co-rotating twin-screw extruder is 160-200°C, the rotation speed is 100-250r / min, the temperature of the injection molding machine is 190-200°C, the injection pressure is 50-70MPa, and the holding pressure is 40-60MPa.

[0022] The beneficial effect of the present invention is as follows: a self-healing two-component elastic fiber provided by the present invention is based on a polylactic acid material, which is blended with a thioether-modified polyurethane material provided by the present invention, and then the surface-modified silica particles provided by the present invention are added as an adhesive to obtain a two-component elastic fiber material with excellent tensile properties, elastic recovery rate and self-healing efficiency. While ensuring the mechanical elastic properties of the fiber, the self-healing property is imparted, thereby broadening the application field of the two-component elastic fiber. DETAILED DESCRIPTION

[0023] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0024] In the following examples, the compound monomers and related reagents used can be purchased from the market, among which polytetrahydrofuran (CAS No.: 25190-06-1, Article No.: 345326) and polylactic acid material (CAS No.: 26100-51-6, Article No.: 38534) were purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., and commercial silica nanoparticles (CAS No.: 112945-52-5, Article No.: HB-630) were purchased from Hubei Huifu Nanomaterials Co., Ltd.

[0025] The self-healing bicomponent elastic fiber materials prepared in the following Examples 1-5 and Comparative Examples 1-3 all include the following steps:

[0026] Preparation of silica nanoparticles:

[0027] 200 mL of anhydrous ethanol, 12.2 mL of deionized water and 16.0 mL of ammonia water were vigorously stirred in a round-bottom flask for 30 min, and then 12.4 mL of tetraethyl silicate was added dropwise. The mixture was stirred for 10 h at room temperature, filtered and separated, and washed three times with deionized water to obtain a precipitate. After drying at 105° C. for 4 h, the precipitate was ground through a 100-mesh sieve to obtain silica nanoparticles.

[0028] Preparation of adhesive:

[0029] S4-1, according to the components and contents shown in Table 1, silica nanoparticles and paraffin were added to 50 mL of didodecyl dimethyl ammonium bromide aqueous solution (80 mg / mL), heated at 80°C for 30 min until the paraffin was dissolved, then vigorously stirred at 80°C and 15000 rpm for 2 min with a high-speed stirrer, cooled to room temperature, washed three times with deionized water, and vacuum dried at room temperature for 2 h to obtain intermediate 1;

[0030] S4-2, add 10 g of intermediate 1 to 20 mL of a methanol solution containing a silane coupling agent, shake and disperse evenly, stir at a constant speed at room temperature for 24 h, wash three times with methanol and chloroform, and vacuum dry at 50° C. for 4 h to obtain intermediate 2;

[0031] S4-3, adding 1 g of intermediate 2 to 10 mL of toluene solution containing a surface modifier and triethylamine, uniformly dispersing by ultrasonication, rapidly stirring and refluxing for 4 h under nitrogen protection, centrifuging, washing three times with methanol and toluene respectively, and vacuum drying at 50° C. for 4 h to obtain the adhesive.

[0032] The adhesive components and contents are shown in Table 1.

[0033] Table 1

[0034]

[0035]

[0036] Preparation of thioether-modified polyurethane material A:

[0037] S8-1, add 15 g of polytetrahydrofuran (relative molecular weight of 2000) into a three-necked round-bottom flask, mechanically stir for 1 h at 100° C. under vacuum conditions to remove moisture, then cool to 70° C., add 5 ml of N,N-dimethylacetamide solution containing 7 g of isophorone diisocyanate and 0.05 g of dibutyltin dilaurate, purge the reaction system with argon, and stir for 2 h to obtain a mixture A;

[0038] S8-2, cooling the mixture A to room temperature, adding 10 ml of N,N-dimethylacetamide solution containing 4 g of bis(4-hydroxyphenyl) disulfide, heating to 40° C., reacting for 1.5 h to obtain a mixture B;

[0039] S8-3, mix mixture B and N,N-dimethylacetamide to prepare a 30wt% N,N-dimethylacetamide solution, pour it into a rectangular polytetrafluoroethylene mold with a size of 150mm×20mm×20mm, place the mold on a hot plate at 80℃ for 48h, and then place the mold in a 130℃ oven for 48h, remove excess solvent to obtain a preform, and then place the preform into a double-zone vertical tube furnace on a fiber stretching tower, with a top zone temperature of 150℃ and a bottom zone temperature of 250℃. After incubation for 3h, the lower part of the preform softens and shrinks under the action of external force. Subsequently, the neck area of ​​the preform is cut off, leaving a connected part, stretched into a thin chain, and the preform is fed into the furnace at a constant speed of 1mm / min. At the same time, the fiber is stretched at a speed of 0.4mm / min to obtain a thioether-modified polyurethane material A.

[0040] Preparation of self-healing bicomponent elastic fiber materials:

[0041] First, the component materials are dried at 80°C for 8h, then the polylactic acid material and the thioether-modified polyurethane material are premixed, and then the adhesive is added, and the blending and granulation are carried out in a co-rotating twin-screw extruder. Finally, the self-healing two-component elastic fiber material is obtained by an injection molding machine; the temperatures of each section of the co-rotating twin-screw extruder are 160°C, 180°C, 190°C, 195°C, 200°C, 200°C, 200°C, and the rotation speed is 200r / min, the temperatures of the injection molding machine are 190°C, 195°C, 200°C, and 195°C, the injection pressure is 60MPa, and the holding pressure is 50MPa.

[0042] Example 1 provides a self-healing two-component elastic fiber material, comprising the following raw materials by mass, 6g of thioether-modified polyurethane material, 88g of polylactic acid material and 6g of adhesive.

[0043] Example 2 provides a self-healing two-component elastic fiber material, comprising the following masses of raw materials, 5g of thioether-modified polyurethane material A, 90g of polylactic acid material and 5g of adhesive B.

[0044] Example 3 provides a self-healing two-component elastic fiber material, comprising the following raw materials by mass, 8g of thioether-modified polyurethane material A, 85g of polylactic acid material and 10g of adhesive C.

[0045] Example 4 provides a self-healing two-component elastic fiber material, which contains the same components and mass as Example 1, except that the thioether-modified polyurethane material A6g is replaced by a thioether-modified polyurethane material B6g, and the preparation method of the thioether-modified polyurethane material B comprises the following steps: first, pour 17g of polytetramethylene ether glycol into a three-necked flask, put it into a 120°C oil bath, and stir it electrically for 30 minutes under an argon atmosphere; then cool the oil bath to 70°C. , then add 9mL of isophorone diisocyanate, 50μL of dibutyltin dilaurate and 6mL of ethyl acetate to the three-necked flask and react for 1 hour; then continue to cool the reaction system to 40°C, add 6mL of ethyl acetate and 3mL of bis(2-hydroxyethyl) disulfide to the three-necked flask and react for 1.5 hours; finally, terminate the reaction and place the obtained viscous liquid in a square polytetrafluoroethylene mold, degas under vacuum, and cure at 50°C for 12 hours to obtain thioether-modified polyurethane material B.

[0046] Example 5 provides a self-healing two-component elastic fiber material, which includes components and mass substantially the same as those of Example 1, except that 6g of the adhesive A is replaced with 6g of commercial silica nanoparticles.

[0047] Comparative Example 1 provides a self-healing two-component elastic fiber material, the components and mass of which are substantially the same as those of Example 1, except that the adhesive A6g is replaced by adhesive A12g.

[0048] Comparative Example 2 provides a self-healing two-component elastic fiber material, the components and mass of which are substantially the same as those of Example 1, except that the adhesive A6g is replaced by adhesive A4g.

[0049] The test method is as follows:

[0050] Tensile strength test: The self-healing bicomponent elastic fiber materials prepared in the above examples and comparative examples were made into tensile test specimens with a size of 63.5 mm×12.7 mm×3.2 mm. According to the ASTM D-638 standard, the test was performed 5 times at a tensile rate of 20 mm / min, and the average value was taken.

[0051] Elasticity performance test: The self-healing bicomponent elastic fiber materials prepared in the above examples and comparative examples were melt-spun into fiber samples, and the elastic recovery rate was tested using GB / T 6506-2001 "Test method for crimping performance of synthetic fiber deformation yarn". The specific test method is: take the above-prepared fiber samples of the same length of 50 cm, hang them at the 0 scale position of the vertical ruler, and let them droop naturally, then add a light load of 0.001 cN / dte to the end of the fiber sample to make it vertical and motionless, and after 30 seconds, measure its length L 0 Remove the light load and add a heavy load of 0.2 cN / dtex to eliminate the curl of the fiber sample and straighten it. After 30 seconds, record the length L 1 Remove the heavy load and add a light load. After 30 seconds, record the length L. 2 The elastic recovery rate of the fiber sample is calculated by the following formula:

[0052]

[0053] Self-healing performance test: The self-healing two-component elastic fiber materials prepared in the above embodiments and comparative examples were prepared into tensile test specimens with a size of 63.5 mm × 12.7 mm × 3.2 mm. The specimens were cut in the middle with a blade, the cross sections were aligned, and placed at room temperature for 2 hours. The self-healing performance of the fibers was evaluated by analyzing the tensile strength after healing. The self-healing efficiency was defined as the ratio of the tensile strength of the healed fibers to the tensile strength of the original specimens.

[0054] The test results are shown in Table 3.

[0055] Table 3

[0056] Tensile strength / MPa Elastic recovery rate / % Self-healing efficiency / % Example 1 45.6 68.1 85.2 Example 2 41.2 63.3 84.3 Example 3 45.1 66.2 82.5 Example 4 44.9 54.7 80.1 Example 5 30.3 35.7 52.1 Comparative Example 1 37.2 45.1 62.4 Comparative Example 2 34.2 46.9 73.2

[0057] It can be seen from Examples 1-3 that the self-healing two-component elastic fiber material provided by the present invention adopts surface-modified silica nanoparticles as an adhesive, and mixes a thioether-modified polyurethane material and a polylactic acid material. The prepared two-component elastic fiber material has excellent tensile strength, elastic recovery rate and self-healing efficiency.

[0058] By comparing Example 1 with Comparative Examples 1-2, it can be seen that when the amount of adhesive used is within a certain range and is prepared using the method provided by the present invention, the obtained bicomponent elastic fiber can have a tensile strength of up to 45.6 MPa, an elastic recovery rate of up to 68.1%, and a self-healing efficiency of up to 85.2%.

[0059] By comparing Example 1 with Examples 4-5, it can be seen that when the modified silica nanoparticles prepared by the method provided by the present invention are used as an adhesive and the thioether-modified polyurethane material prepared by the method provided by the present invention is used in combination, the tensile strength, elastic recovery rate and self-healing efficiency performance of the prepared two-component elastic fiber material are improved.

[0060] In summary, the present invention provides a self-healing two-component elastic fiber and a preparation method thereof, which uses surface-modified silica nanoparticles as an adhesive and is blended with thioether-modified polyurethane materials and polylactic acid materials to obtain a two-component elastic fiber material with excellent tensile properties, elastic recovery rate and self-healing efficiency. While ensuring the mechanical elastic properties of the fiber, the fiber is given the ability to self-heal, thereby broadening the application areas of the two-component elastic fiber in the fields of biosensing, soft robots, etc.

[0061] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-healing bicomponent elastic fiber material, characterized in that: The self-healing two-component elastic fiber material comprises the following raw materials: 5-10 g of thioether-modified polyurethane material, 85-95 g of polylactic acid material, and 5-10 g of adhesive.

2. The self-healing bicomponent elastic fiber material according to claim 1, characterized in that: The raw materials for preparing the adhesive include silicon dioxide nanoparticles, paraffin, triethylamine, a surfactant, a silane coupling agent and a surface treatment agent, and the mass ratio of the silicon dioxide nanoparticles to the paraffin is 1:(5-10).

3. The self-healing bicomponent elastic fiber material according to claim 2, characterized in that: The silane coupling agent comprises one of diethylenetriaminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and γ-mercaptopropyltrimethoxysilane.

4. The self-healing bicomponent elastic fiber material according to claim 2, characterized in that: The preparation steps of the adhesive include: S4-1: Add silica nanoparticles and paraffin to the aqueous solution containing surfactant, heat at 70-90°C for 20-35 min, and then stir at 70-90°C with a high-speed stirrer. Stir vigorously at 10000-20000 rpm for 1-5 min, cool to room temperature, and then post-treat to obtain intermediate 1; S4-2: adding intermediate 1 to a methanol solution containing a silane coupling agent, oscillating and dispersing the mixture evenly, stirring the mixture at a constant speed at room temperature for 12-48 hours, and performing post-treatment to obtain intermediate 2; S4-3: Add intermediate 2 to a toluene solution containing a surface treatment agent and triethylamine, disperse uniformly by ultrasonication, rapidly stir and reflux for 1-5 hours under nitrogen protection, centrifuge and wash, and vacuum dry at 40-60° C. for 1-5 hours to obtain an adhesive.

5. The self-healing bicomponent elastic fiber material according to claim 4, characterized in that: The preparation step of the silicon dioxide nanoparticles in step S4-1 comprises: vigorously stirring anhydrous ethanol, deionized water and ammonia water in a round-bottom flask for 10-40 minutes, then adding tetraethyl silicate dropwise, stirring and reacting at room temperature for 6-15 hours, filtering, separating and washing to obtain a precipitate, drying at 100-110° C. for 1-5 hours, and grinding through a 90-100 mesh sieve to obtain silicon dioxide nanoparticles.

6. The self-healing bicomponent elastic fiber material according to claim 1, characterized in that: The raw materials for preparing the thioether-modified polyurethane material include polytetrahydrofuran, isocyanate derivatives, bis(4-hydroxypropyl) disulfide and a catalyst.

7. The self-healing bicomponent elastic fiber material according to claim 6, characterized in that: The relative molecular mass of the polytetrahydrofuran is 1000-2000, the isocyanate derivative comprises one of 2,4-toluene diisocyanate, isophorone diisocyanate and diphenylmethane-4,4'-diisocyanate, and the catalyst is one of dibutyltin dilaurate and stannous octoate.

8. The self-healing bicomponent elastic fiber material according to claim 6, characterized in that: The preparation steps of the thioether-modified polyurethane material include: S8-1: Add polytetrahydrofuran into a three-necked round-bottom flask, mechanically stir at 90-110°C under vacuum for 0.5-1.5h, then cool to 60-80°C, add N,N-dimethylacetamide solution containing isocyanate derivatives and dibutyltin dilaurate, and stir under argon atmosphere for 1-2h to obtain a mixture A; S8-2: Cool mixture A to room temperature, add N,N-dimethylacetamide solution containing bis(4-hydroxyphenyl) disulfide, heat to 40-50° C., and react for 1-2 h to obtain mixture B; S8-3: Mix mixture B and N,N-dimethylacetamide to prepare a 10-40wt% N,N-dimethylacetamide solution, then pour it into a mold and heat it for 36-48 hours to prepare a thioether-modified polyurethane material by a hot fiber stretching method.

9. The method for preparing the self-healing two-component elastic fiber material according to any one of claims 1 to 8 comprises the following steps: drying each component material at 75-85°C for 4-10 hours, premixing a polylactic acid material and a thioether-modified polyurethane material, then adding an adhesive, blending and granulating in a co-rotating twin-screw extruder, and then obtaining the self-healing two-component elastic fiber material through an injection molding machine.

10. The method for preparing the self-healing bicomponent elastic fiber material according to claim 9, characterized in that: The temperature of the co-rotating twin-screw extruder is 160-200° C., the rotation speed is 100-250 r / min, the temperature of the injection molding machine is 190-200° C., the injection pressure is 50-70 MPa, and the holding pressure is 40-60 MPa.

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