Antibacterial polyurethane nanofiber / short fiber blended yarn for shoe materials and preparation method thereof

Abstract

The present invention relates to an antibacterial polyurethane nanofiber / short fiber blended yarn for shoe materials and a preparation method thereof. The antibacterial spinning solution is electrostatically spun to deposit the obtained antibacterial nanofiber on a short fiber net to obtain a short fiber net containing antibacterial nanofibers, and a subsequent spinning process is performed to obtain an antibacterial polyurethane nanofiber / short fiber blended yarn. In the preparation method of the present invention, the antibacterial functional group is grafted onto the polyurethane molecular chain without migration, and the obtained yarn has good antibacterial effect, high stability and long-lasting performance.

Description

Technical Field

[0001] The invention belongs to the field of textiles, and particularly relates to an antibacterial polyurethane nanofiber / short fiber blended yarn for shoe materials and a preparation method thereof. Background Art

[0002] The human foot is wrapped or in shoes for about 2 / 3 of the time. When wearing shoes for a long time, the foot is in a relatively closed shoe cavity environment. The closed shoe cavity has excellent humidity and temperature, and microorganisms will multiply in large numbers, and then decompose and utilize organic matter in the metabolites of the foot skin, producing pungent odors such as sour odor. Long-term contact with the foot skin will have a destructive effect on the material, color and performance of the shoe lining. In severe cases, it will also cause stubborn diseases such as foot odor and tinea pedis, which will endanger human health. Therefore, the root cause of eliminating odor lies in inhibiting the growth and reproduction of microorganisms in the shoe cavity. With the increasing level of consumption, people have put forward higher and newer requirements for shoe materials.

[0003] In order to achieve these goals, the research and development of new materials, new processes, new technologies and new products mainly focus on health, hygiene, comfort, beauty and other aspects, while the development of functional footwear is also increasingly valued. Electrospinning is one of the popular and simple methods for preparing nano-scale fibers that has emerged in recent years. The antibacterial polyurethane nanofiber yarn processed by electrospinning technology not only has the specific effects of ordinary nanomaterials, such as surface effect and small size effect, but also has a fiber structure with a smaller diameter and performance characteristics that are superior to antibacterial agents. It has great application potential in many high-tech fields (such as biomedicine, footwear, etc.).

[0004] CN112553734 discloses a method for preparing a non-ironing multifunctional blended yarn using electrostatic spinning nanotechnology, wherein the spinning solution is prepared by stirring and dissolving low-melting polyester with a solvent, and adding functional materials, and the blended yarn prepared can improve the non-ironing performance of the yarn and improve the mechanical properties of the yarn, and at the same time, due to the addition of functional materials in the electrostatic spinning process, the fabric has corresponding functional properties. However, this method is to electrostatically spin a mixture of an antibacterial agent and polyurethane, and the antibacterial agent migrates in the polyurethane matrix, resulting in uneven distribution of the antibacterial agent in the yarn, and the antibacterial agent is easily separated and falls off during the use of the yarn, and there are disadvantages such as poor antibacterial durability and stability. Summary of the invention

[0005] In view of the defects of the prior art, the technical problem to be solved by the present invention is to provide an antibacterial polyurethane nanofiber / short fiber blended yarn for shoe materials and a preparation method thereof.

[0006] A method for preparing antibacterial polyurethane nanofibers of the present invention comprises:

[0007] (1) thermoplastic polyurethane TPU, hexamethylene diisocyanate HDI, a catalyst, and a solvent are mixed, and then reacted under nitrogen conditions to obtain thermoplastic polyurethane TPU-HDI grafted with isocyanate groups;

[0008] (2) reacting thermoplastic polyurethane TPU-HDI grafted with isocyanate groups and polyethylene glycol PEG under nitrogen conditions to obtain TPU-PEG;

[0009] (3) reacting the conditioning agent, TPU-PEG, and allyl glycidyl ether AGE to obtain TPU-AGE;

[0010] (4) mixing water and dimethyldiallyl ammonium chloride (DMDAAC), raising the temperature, adding the initiator and TPU-AGE solution dropwise, and keeping the temperature to obtain the antibacterial polyurethane TPU-DMDAAC-AGE;

[0011] (5) The antibacterial polyurethane TPU-DMDAAC-AGE and an organic solvent are mixed to obtain a spinning solution, and then electrospun to obtain antibacterial polyurethane nanofibers.

[0012] The preferred method of the above preparation method is as follows:

[0013] The thermoplastic polyurethane TPU is a pretreated thermoplastic polyurethane TPU; the pretreated thermoplastic polyurethane TPU is a thermoplastic polyurethane TPU pretreated with methanol for 20-25 hours to remove small molecular residues on the surface;

[0014] In the step (1), the relative molecular mass of the thermoplastic polyurethane TPU is 1500-2500; the catalyst is dibutyltin dilaurate; and the solvent is one or more of ethyl acetate, acetone and toluene.

[0015] In the step (1), the mass ratio of thermoplastic polyurethane TPU and hexamethylene diisocyanate HDI is (15-35): (5-15), and the content of the catalyst is 1-10% of the mass of the total reaction material; the reaction temperature in the step (1) under nitrogen conditions is 20-25° C.; and the reaction time is 1-2 h.

[0016] In the step (2), the mass ratio of TPU-HDI to polyethylene glycol PEG is (20-50):(5-25); the reaction temperature in the step (2) under nitrogen conditions is 30-40°C; and the reaction time is 10-15h.

[0017] In the step (3), the conditioning agent is sodium p-toluenesulfonate; n(TPU-PEG):n(AGE)=5:6, and the content of the conditioning agent is 2% of the mass of AGE; the reaction temperature is 100-110° C., and the reaction time is 1-3 h.

[0018] The initiator in step (4) is sodium persulfate; the solvent of the TPU-AGE solution is ethanol; the mass percentage of dimethyldiallylammonium chloride DMDAAC in the total reaction material in step (4) is 15-25%, the mass percentage of the initiator is 15%-20%, and the mass percentage of TPU-AGE is 35%-45%; the temperature is raised to 75-80° C. and the insulation time is 6-8 hours.

[0019] In step (5), the organic solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide and tetrahydrofuran; the spinning solution concentration is 20-29wt%;

[0020] The electrospinning process parameters in step (5) are as follows: the applied voltage is 7.6-8.2 KV, the receiving distance is 10-12.5 cm, the spinning temperature is 23-27° C., the relative humidity is 25-35%, and the mass ratio of antibacterial nanofibers to short fibers is 1:200 to 1:50.

[0021] The antibacterial polyurethane nanofiber / short fiber blended yarn of the invention is obtained by depositing the antibacterial polyurethane nanofiber on a short fiber net to obtain a short fiber net containing the antibacterial nanofiber, and then combing and spinning the net into yarn.

[0022] The antibacterial polyurethane nanofibers are deposited on the short fiber web by electrospinning the spinning solution to prepare the antibacterial polyurethane nanofibers, and the short fiber web is used as a receiving device to directly deposit the antibacterial polyurethane nanofibers.

[0023] The short fibers are one or more of modal, viscose, lyocell, cotton and chemical fiber.

[0024] During the combing process, the antibacterial spinning solution is electrospun simultaneously by an electrospinning device installed on the combing machine, so that the antibacterial nanofibers obtained by electrospinning are deposited on the short fiber web.

[0025] The yarn-forming process comprises: blowing and carding, combing, drawing, roving and spun yarn.

[0026] The invention discloses an application of the antibacterial polyurethane nanofiber / short fiber blended yarn in shoe fabrics, such as antibacterial yarn for shoe materials.

[0027] The present invention proposes to graft an antibacterial agent onto a polyurethane matrix, spray antibacterial nanofibers on a combed short fiber web by electrostatic spinning, and then make antibacterial yarn through traditional spinning processes such as drawing, roving and spinning, thereby providing a new method for processing antibacterial yarn for shoe materials.

[0028] Beneficial Effects

[0029] (1) The present invention grafts the antibacterial agent onto polyurethane, making it difficult for the antibacterial agent to migrate and fall off during the use of the yarn and evenly distributed, so that the yarn has a durable and stable antibacterial effect to avoid bacteria from adhering to, growing and multiplying on its surface, thereby preventing bacteria from breeding and emitting odors that cause long-term harm to human health.

[0030] (2) The method for providing short fiber yarn with long-lasting antibacterial functionalization provided by the present invention is to graft antibacterial functional groups onto the polyurethane molecular chain by a grafting method before preparing the spinning solution. Compared with the method of preparing the spinning solution by mixing the antibacterial agent and polyurethane, the antibacterial polyurethane nanofiber / short fiber blended yarn for shoes produced by this method has good antibacterial effect, high stability and long-lasting performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The invention is a synthetic formula for the preparation of antibacterial polyurethane. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended 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 fall within the scope limited by the appended claims of the application equally.

[0033] 1. Source of raw materials

[0034] Polyurethane (TPU), BASF (China) Co., Ltd.; Diallyl dimethylammonium chloride (DMDAAC): 60%, Shandong Luyue Chemical Co., Ltd.; Allyl glycidyl ether (AGE), Hangzhou Sloan Materials Technology Co., Ltd.; Sodium p-toluenesulfonate, Shanghai Titan Co., Ltd.; Ethanol, polyethylene glycol (PEG) (relative molecular weight 2000), dibutyltin dilaurate, acetone, toluene, hexamethylene diisocyanate (HDI), Shanghai Aladdin Biochemical Technology Co., Ltd.; Dimethylformamide (DMF), Shanghai Sinopharm Chemical Reagent Co., Ltd.; Dimethylacetamide (DMAc), Shanghai Sinopharm Chemical Reagent Co., Ltd.; Tetrahydrofuran (THF), Aladdin; Staphylococcus aureus (ATCC6538), Shanghai Jiachu Bioengineering Co., Ltd.

[0035] 2. Test standards and methods

[0036] The antibacterial properties of yarns were quantitatively evaluated with reference to the standard GB / 20944.3-2008 “Evaluation of antibacterial properties of textiles Part 3: Oscillation method”.

[0037] Example 1

[0038] Preparation of antibacterial polyurethane spinning solution:

[0039] (1) 25 g of thermoplastic polyurethane (TPU) was pretreated with methanol for 24 h to remove the small molecular residues on the surface, and then reacted with 10 g of methylene diisocyanate (HDI) under nitrogen conditions, with 0.2% by mass of dibutyltin dilaurate added, and reacted in ethyl acetate for 1-2 h to obtain TPU-HDI grafted with isocyanate groups;

[0040] (2) 40 g of TPU–HDI was reacted with 15 g of polyethylene glycol (PEG) at 35 °C under nitrogen for 12 h to obtain TPU–PEG;

[0041] (3) heating to 105 °C, adding 0.06 g of sodium p-toluenesulfonate (2% of the mass of AGE), and reacting TPU-PEG with allyl glycidyl ether (AGE) for 2 h to obtain TPU-AGE;

[0042] (4) Add an appropriate amount of distilled water and 20% dimethyldiallyl ammonium chloride (DMDAAC) into a four-necked flask, heat it to 80°C, and continuously drip 17% persulfate aqueous solution and 40% TPU-AGE ethanol solution for about 2 hours. After the dripping is completed, keep the temperature for 6 hours, react for a period of time, and cool down to obtain a colorless, transparent and viscous antibacterial polyurethane TPU-DMDAAC-AGE;

[0043] (5) dissolving the antibacterial polyurethane in DMF solvent and stirring at room temperature for 12 hours to obtain an antibacterial polyurethane spinning solution with a mass concentration of 20%;

[0044] (6) The antibacterial spinning solution in step (5) is subjected to electrospinning to deposit the obtained antibacterial nanofibers onto a viscose staple fiber web to obtain a staple fiber web containing antibacterial agent nanofibers. The process parameters of the electrospinning are: voltage of 8 kV, receiving distance of 10 cm, spinning environment temperature of 25 ° C, spinning environment humidity of 30%, and the mass ratio of antibacterial nanofibers to viscose staple fibers is 1:100.

[0045] (7) After being formed into strips, the staple fiber web enters the subsequent spinning process such as coarse yarn and fine yarn, and finally obtains the antibacterial polyurethane nanofiber / viscose staple fiber blended yarn for shoe materials. The antibacterial rate of the yarn against Staphylococcus aureus reaches 95%, and the antibacterial rate still reaches 91% after 50 washings, and the antibacterial performance is long-lasting.

[0046] Example 2

[0047] (1) 25 g of thermoplastic polyurethane (TPU) was pretreated with methanol for 24 h to remove the small molecular residues on the surface, and then reacted with 10 g of methylene diisocyanate (HDI) under nitrogen conditions, with 0.2% by mass of dibutyltin dilaurate added, and reacted in ethyl acetate for 1-2 h to obtain TPU-HDI grafted with isocyanate groups;

[0048] (2) 40 g of TPU–HDI was reacted with 15 g of polyethylene glycol (PEG) at 35 °C under nitrogen for 12 h to obtain TPU–PEG;

[0049] (3) heating to 105 °C, adding 0.06 g of sodium p-toluenesulfonate (2% of the mass of AGE), and reacting TPU-PEG with allyl glycidyl ether (AGE) for 2 h to obtain TPU-AGE;

[0050] (4) Add an appropriate amount of distilled water and 20% dimethyldiallyl ammonium chloride (DMDAAC) into a four-necked flask, heat it to 80°C, and continuously drip 17% persulfate aqueous solution and 40% TPU-PGE ethanol solution for about 2 hours. After the dripping is completed, keep the temperature for 6 hours, react for a period of time, and cool down to obtain a colorless, transparent and viscous antibacterial polyurethane (TPU-DMDAAC-AGE);

[0051] (5) dissolving the antibacterial polyurethane in DMF solvent and stirring at room temperature for 13 hours to obtain an antibacterial polyurethane spinning solution with a mass concentration of 29%;

[0052] (6) The antibacterial spinning solution in step (5) is subjected to electrospinning to deposit the obtained antibacterial nanofibers onto a viscose staple fiber web to obtain a staple fiber web containing antibacterial agent nanofibers. The process parameters of the electrospinning are: voltage of 8 kV, receiving distance of 15 cm, spinning environment temperature of 25 ° C, spinning environment humidity of 30%, and the mass ratio of antibacterial nanofibers to viscose staple fibers is 1:100.

[0053] (7) After being formed into strips, the staple fiber web enters the subsequent yarn-forming process such as coarse yarn and fine yarn, and finally obtains antibacterial polyurethane nanofiber / viscose staple fiber blended shoe yarn, the antibacterial rate of the yarn against Staphylococcus aureus reaches 98%, and the antibacterial rate still reaches 93% after 50 water washings, and the antibacterial performance is long-lasting. Under the same conditions, the antibacterial agent DMDAAC is directly mixed with polyurethane to prepare the spinning solution for electrostatic spinning, and the antibacterial polyurethane nanofiber / viscose staple fiber blended shoe yarn is obtained. The antibacterial rate of the yarn against Staphylococcus aureus is 95%, and the antibacterial rate is reduced to 80% after 50 water washings. By comparison, it can be seen that the yarn prepared by the present invention has good antibacterial effect, high stability and long-lasting performance.

Claims

1. A method for preparing antibacterial polyurethane nanofibers, comprising: (1) thermoplastic polyurethane TPU, hexamethylene diisocyanate HDI, a catalyst, and a solvent are mixed, and then reacted under nitrogen conditions to obtain thermoplastic polyurethane TPU-HDI grafted with isocyanate groups; (2) reacting thermoplastic polyurethane TPU-HDI grafted with isocyanate groups and polyethylene glycol PEG under nitrogen conditions to obtain TPU-PEG; (3) reacting a conditioning agent, TPU-PEG, and allyl glycidyl ether AGE to obtain TPU-AGE; wherein the conditioning agent is sodium p-toluenesulfonate; (4) mixing water and dimethyldiallyl ammonium chloride (DMDAAC), raising the temperature, adding the initiator and TPU-AGE solution dropwise, and keeping the temperature, thereby obtaining the antibacterial polyurethane TPU-DMDAAC-AGE; (5) The antibacterial polyurethane TPU-DMDAAC-AGE and an organic solvent are mixed to obtain a spinning solution, and then electrospun to obtain antibacterial polyurethane nanofibers.

2. The preparation method according to claim 1, characterized in that: The thermoplastic polyurethane TPU is a pretreated thermoplastic polyurethane TPU; the pretreated thermoplastic polyurethane TPU is a thermoplastic polyurethane TPU that is pretreated with methanol for 20-25 hours to remove small molecular residues on the surface; In the step (1), the relative molecular mass of the thermoplastic polyurethane TPU is 1500-2500; the catalyst is dibutyltin dilaurate; and the solvent is one or more of ethyl acetate, acetone and toluene.

3. The preparation method according to claim 1, characterized in that: In the step (1), the mass ratio of thermoplastic polyurethane TPU and hexamethylene diisocyanate HDI is (15-35): (5-15), and the content of the catalyst is 1-10% of the mass of the total reaction material; the reaction temperature in the step (1) under nitrogen conditions is 20-25° C.; and the reaction time is 1-2 h.

4. The preparation method according to claim 1, characterized in that: In the step (2), the mass ratio of TPU-HDI to polyethylene glycol PEG is (20-50):(5-25); the reaction temperature in the step (2) under nitrogen conditions is 30-40°C; and the reaction time is 10-15h.

5. The preparation method according to claim 1, characterized in that: In the step (3), n(TPU-PEG):n(AGE)=5:6, the content of the conditioning agent is 1-10% of the mass of AGE; the reaction temperature is 100-110° C., and the reaction time is 1-3 h.

6. The preparation method according to claim 1, characterized in that: The initiator in step (4) is sodium persulfate; the solvent of the TPU-AGE solution is ethanol; the mass percentage of dimethyldiallylammonium chloride DMDAAC in the reaction system of step (4) is 15-25%, the mass percentage of the initiator is 15%-20%, and the mass percentage of TPU-AGE is 35%-45%; the temperature is raised to 75-80° C. and the insulation time is 6-8 hours.

7. The preparation method according to claim 1, characterized in that: In step (5), the organic solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide and tetrahydrofuran; the spinning solution concentration is 20-29wt%; The electrospinning process parameters in step (5) are as follows: the electrospinning applied voltage is 7.6-8.2 KV, the receiving distance is 10-12.5 cm, the spinning temperature is 23-27° C., and the ambient relative humidity is 25-35%.

8. An antibacterial polyurethane nanofiber / short fiber blended yarn, characterized in that: The antibacterial polyurethane nanofibers according to claim 1 are deposited on a short fiber web, and then combed and yarn-formed to obtain the fibers.

9. The blended yarn according to claim 8, characterized in that: The short fibers are one or more of modal, viscose, lyocell, cotton, and chemical fibers; the mass ratio of the antibacterial polyurethane nanofibers to the short fibers is 1:200 to 1:

50.

10. Use of the antibacterial polyurethane nanofiber / short fiber blended yarn according to claim 8 in shoe fabrics.

Images