Long-acting antibacterial fiber and its preparation process

Abstract

The application relates to the technical field of fibers, and discloses a long-acting antibacterial fiber and a preparation process thereof. 1,3,5-tri(methyl acetate trimethyl ammonium bromide) benzene and ethylenediamine are subjected to amidation condensation reaction to obtain a quaternary ammonium salt antibacterial agent, then electrostatic spinning is carried out with polyurethane resin to obtain the long-acting antibacterial fiber. The antibacterial agent contains a large number of positive charges, can destroy the negatively charged cell membranes of bacteria, inhibit the growth of bacteria, has a good killing effect, and significantly improves the long-acting antibacterial performance of the fiber. The quaternary ammonium salt antibacterial agent contains a large number of amide bonds, forms hydrogen bond force with urethane groups of the polyurethane, has good compatibility, has little influence on the mechanical properties of the fiber, the polyurethane fiber maintains good breaking strength and breaking elongation, and can have good mechanical properties and antibacterial performance.

Description

Technical Field

[0001] This invention relates to the field of fiber technology, specifically to a long-lasting antibacterial fiber and its preparation process. Background Technology

[0002] Spandex fiber's main component is polyurethane, which possesses excellent moisture absorption, elasticity, flexibility, and a soft hand feel, making it important in high-end clothing fabrics. However, due to its strong moisture absorption, spandex fiber and fabrics easily create a warm and humid microenvironment, fostering bacterial and microbial growth, producing odors, and potentially causing skin allergies or inflammation, posing significant health risks. Therefore, antibacterial modification of spandex fiber and fabrics is of great importance.

[0003] Antibacterial agents for fibers include inorganic antibacterial agents such as nano-silver and organic antibacterial agents such as quaternary ammonium salts. CN115652473B discloses a method for preparing spandex antibacterial fibers and their application in antibacterial fabrics. The method involves wet spinning quaternary ammonium salt-modified cellulose with polyurethane, resulting in spandex fibers with good antibacterial and hydrophilic properties. However, if the added antibacterial agent has poor compatibility with the polyurethane matrix, it will affect the fiber's mechanical properties, making it difficult to achieve both good mechanical and antibacterial properties. Summary of the Invention

[0004] This invention solves the problem of poor antibacterial properties of polyurethane fibers while maintaining good mechanical strength.

[0005] Technical solution: A preparation process for a long-lasting antibacterial fiber:

[0006] (1) Add 1,3,5-tris(bromomethyl)benzene and N,N-dimethylglycine methyl ester to acetonitrile, stir the reaction, rotary evaporate, wash the product with petroleum ether, and then recrystallize in an aqueous ethanol solution to obtain 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene. The reaction formula is as follows:

[0007] .

[0008] (2) Add 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene and alkyl diamine to N,N-dimethylacetamide, stir to react, pour the solution into ethanol, filter, wash the product with ethanol, dry, and obtain the quaternary ammonium salt antibacterial agent. The reaction formula is:

[0009] .

[0010] (3) Add polyurethane resin and quaternary ammonium salt antibacterial agent to a mixed solution of N,N-dimethylformamide and tetrahydrofuran, stir and degas under vacuum to prepare a spinning solution, and perform electrospinning by an electrospinning machine to obtain long-lasting antibacterial fiber.

[0011] Preferably, the molar ratio of 1,3,5-tris(bromomethyl)benzene and N,N-dimethylglycine methyl ester in (1) is 1:(3.6-4.5).

[0012] Preferably, the reaction temperature in (1) is 75-80℃ and the reaction time is 8-12h.

[0013] Preferably, the reaction temperature in (2) is 130-145℃ and the reaction time is 12-18h.

[0014] Preferably, in (2), the molar ratio of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene to alkyl diamine is 1:(1.5-1.7).

[0015] Preferably, in (2) the alkyl diamine is ethylenediamine, 1,3-propanediamine or 1,4-butanediamine.

[0016] Preferably, the mass ratio of polyurethane resin to quaternary ammonium salt antibacterial agent in (3) is 100:(1.5-5).

[0017] Preferably, in (3), the volume ratio of N,N-dimethylformamide and tetrahydrofuran is 1:(0.8-1).

[0018] Preferably, in (3), the flow rate of the spinning solution during electrospinning is 1-4 mL / h, the spinning voltage is 17-22 kV, and the receiving distance is 16-25 cm.

[0019] The beneficial technical effects of this invention are as follows: Amidation condensation reaction is performed on 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene and ethylenediamine to obtain a quaternary ammonium salt antibacterial agent. This agent is then electrospun with polyurethane resin to obtain a long-lasting antibacterial fiber. This quaternary ammonium salt antibacterial agent contains a large amount of positive charge, which can destroy the negatively charged cell membranes of bacteria, inhibit bacterial growth, and exert a good bactericidal effect, significantly improving the antibacterial performance of the fiber. As a macromolecular polymer, the quaternary ammonium salt antibacterial agent does not easily migrate within the fiber matrix. Furthermore, the quaternary ammonium salt antibacterial agent contains dendritic three-dimensional molecular chains, forming a three-dimensional physical interpenetrating network with the polyurethane molecular chains, tightly binding with the polyurethane. It is not easily removed from the fiber even after repeated washing, giving the fiber long-lasting antibacterial properties.

[0020] The quaternary ammonium salt antibacterial agent of the present invention contains a large number of amide bonds, which form hydrogen bonds with the urethane groups of polyurethane. The two have good compatibility and have little impact on the mechanical properties of the fiber, so that the polyurethane fiber maintains good breaking strength and elongation at break, and can have both good mechanical properties and antibacterial properties. Detailed Implementation

[0021] To provide a detailed understanding of the technical features and content of this invention, preferred embodiments will be described in more detail below. While preferred embodiments of the invention are described in the examples, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0022] The polyurethane resin described below is sourced from Dongguan Hongke Plastic Raw Materials Co., Ltd.

[0023] Example 1: (1) 20 mmol of 1,3,5-tris(bromomethyl)benzene and 90 mmol of N,N-dimethylglycine methyl ester were added to 600 mL of acetonitrile, heated to 75 °C, stirred and refluxed for 12 h, evaporated by rotary evaporation, washed with petroleum ether, and then recrystallized in an aqueous ethanol solution to obtain 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene.

[0024] (2) Add 20 mmol of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene and 30 mmol of ethylenediamine to 40 mL of N,N-dimethylacetamide, heat to 140 °C, stir and react for 18 h, pour the solution into ethanol, filter, wash the product with ethanol, dry, and obtain quaternary ammonium salt antibacterial agent.

[0025] (3) Add 1 kg of polyurethane resin and 15 g of quaternary ammonium salt antibacterial agent to a mixed solution of 4 L N,N-dimethylformamide and 4 L tetrahydrofuran, stir and degas under vacuum to prepare a spinning solution, and perform electrospinning by an electrospinning machine. The spinning solution flow rate is 2 mL / h, the spinning voltage is 22 kV, and the receiving distance is 20 cm to obtain long-lasting antibacterial fiber.

[0026] Example 2: (1) 20 mmol of 1,3,5-tris(bromomethyl)benzene and 72 mmol of N,N-dimethylglycine methyl ester were added to 400 mL of acetonitrile, heated to 80 °C, stirred and refluxed for 8 h, evaporated by rotary evaporation, washed with petroleum ether, and then recrystallized in an aqueous ethanol solution to obtain 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene.

[0027] (2) Add 20 mmol of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene and 32 mmol of 1,4-butanediamine to 50 mL of N,N-dimethylacetamide, heat to 130 °C, stir and react for 18 h, pour the solution into ethanol, filter, wash the product with ethanol, dry, and obtain quaternary ammonium salt antibacterial agent.

[0028] (3) Add 1 kg of polyurethane resin and 25 g of quaternary ammonium salt antibacterial agent to a mixed solution of 5 L of N,N-dimethylformamide and 5 L of tetrahydrofuran. After stirring, degas the solution under vacuum to prepare a spinning solution. Electrospinning is performed using an electrospinning machine with a spinning solution flow rate of 1 mL / h, a spinning voltage of 22 kV, and a receiving distance of 20 cm to obtain long-lasting antibacterial fibers.

[0029] Example 3: (1) Add 20 mmol of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene (prepared in the same way as in Example 1) and 30 mmol of ethylenediamine to 40 mL of N,N-dimethylacetamide, heat to 145 °C, stir and react for 12 h, pour the solution into ethanol, filter, wash the product with ethanol, dry, and obtain quaternary ammonium salt antibacterial agent.

[0030] (2) Add 1 kg of polyurethane resin and 35 g of quaternary ammonium salt antibacterial agent to a mixed solution of 5 L N,N-dimethylformamide and 4 L tetrahydrofuran, stir and degas under vacuum to prepare a spinning solution, and perform electrospinning by an electrospinning machine. The spinning solution flow rate is 4 mL / h, the spinning voltage is 17 kV, and the receiving distance is 16 cm to obtain long-lasting antibacterial fiber.

[0031] Example 4: (1) Add 20 mmol of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene (prepared in the same way as in Example 1) and 34 mmol of 1,3-propanediamine to 50 mL of N,N-dimethylacetamide, heat to 140 °C, stir and react for 18 h, pour the solution into ethanol, filter, wash the product with ethanol, dry, and obtain quaternary ammonium salt antibacterial agent.

[0032] (2) Add 1 kg of polyurethane resin and 50 g of quaternary ammonium salt antibacterial agent to a mixed solution of 5 L of N,N-dimethylformamide and 5 L of tetrahydrofuran. After stirring, degas the solution under vacuum to prepare a spinning solution. Electrospinning is performed using an electrospinning machine with a spinning solution flow rate of 2 mL / h, a spinning voltage of 20 kV, and a receiving distance of 25 cm to obtain long-lasting antibacterial fibers.

[0033] Comparative Example 1: (1) 1 kg of polyurethane resin was added to a mixed solution of 4 L N,N-dimethylformamide and 4 L tetrahydrofuran. After stirring, the solution was degassed under vacuum to prepare a spinning solution. Electrospinning was performed using an electrospinning machine with a spinning solution flow rate of 2 mL / h, a spinning voltage of 22 kV, and a receiving distance of 20 cm to obtain polyurethane fibers.

[0034] Comparative Example 2: (1) 1 kg of polyurethane resin and 15 g of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene (prepared in the same way as in Example 1) were added to a mixed solution of 4 L of N,N-dimethylformamide and 4 L of tetrahydrofuran. After stirring, the solution was degassed under vacuum to prepare a spinning solution. Electrospinning was performed using an electrospinning machine with a spinning solution flow rate of 2 mL / h, a spinning voltage of 22 kV, and a receiving distance of 20 cm to obtain polyurethane fibers.

[0035] Comparative Example 3: (1) 30 mmol of 1,4-di(bromomethyl)benzene and 90 mmol of N,N-dimethylglycine methyl ester were added to 600 mL of acetonitrile. The mixture was heated to 75 °C, stirred, refluxed, and stirred for 12 h. The product was then evaporated by rotary evaporation, washed with petroleum ether, and recrystallized in an aqueous ethanol solution to obtain 1,4-di(methyl acetate trimethylammonium bromide)benzene, with the structural formula: .

[0036] (2) Add 30 mmol of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene and 30 mmol of ethylenediamine to 40 mL of N,N-dimethylacetamide, heat to 140 °C, stir and react for 18 h, pour the solution into ethanol, filter, wash the product with ethanol, dry, and obtain quaternary ammonium salt antibacterial agent.

[0037] (3) Add 1 kg of polyurethane resin and 15 g of quaternary ammonium salt antibacterial agent to a mixed solution of 4 L N,N-dimethylformamide and 4 L tetrahydrofuran, stir and degas under vacuum to prepare a spinning solution, and perform electrospinning by an electrospinning machine. The spinning solution flow rate is 2 mL / h, the spinning voltage is 22 kV, and the receiving distance is 20 cm to obtain polyurethane fiber.

[0038] The antibacterial rate and antibacterial properties of the fibers were tested according to GB / T 20944.3-2008 standard, with *Escherichia coli* as the test species. The antibacterial rate Y = (WQ) / W × 100%. W is the average concentration of viable bacteria (CFU / mL) in the flask after 18 hours of shaking contact with the control sample (polyurethane fiber of Comparative Example 1). Q is the average concentration of viable bacteria (CFU / mL) in the flask after 18 hours of shaking contact with the experimental samples (Examples 1-4 and Comparative Examples 2-3, respectively).

[0039] The fibers were washed and dried 40 times according to the GB / T 8629-2017 standard, and then the antibacterial rate was tested.

[0040] Tensile properties were tested according to FZ / T 50006-2013 standard.

[0041] Table 1 Performance Tests

[0042]

[0043] Compared to Comparative Example 1, the polyurethane fibers of Examples 1-4 exhibit a high antibacterial rate, primarily due to the addition of a positively charged quaternary ammonium salt antibacterial agent. This agent disrupts the negatively charged cell membranes of bacteria, inhibiting bacterial growth and effectively killing bacteria, thus significantly improving the fiber's antibacterial properties. Even after washing, the fiber retains a high antibacterial rate, mainly because the quaternary ammonium salt antibacterial agent is a macromolecular polymer that does not easily migrate within the fiber matrix. Furthermore, the quaternary ammonium salt antibacterial agent contains dendritic three-dimensional molecular chains, forming a three-dimensional interpenetrating network with the polyurethane molecular chains, resulting in a tight bond that is difficult to remove from the fiber even after repeated washing, thus providing long-lasting antibacterial properties. The quaternary ammonium salt antibacterial agent contains a large number of amide bonds, forming hydrogen bonds with the urethane groups of the polyurethane. The good compatibility of the two has minimal impact on the fiber's mechanical properties, allowing the polyurethane fiber to maintain good tensile strength and elongation at break.

[0044] Compared with Example 1, the 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene added in Comparative Example 2 is a small molecule compound that easily migrates from the fiber matrix. After repeated washing, the antibacterial rate of the fiber decreases significantly, and its compatibility with polyurethane is poor, which affects the mechanical properties of the fiber. The breaking strength and elongation at break show a downward trend.

[0045] The quaternary ammonium salt antibacterial agent in Comparative Example 3 does not contain dendritic three-dimensional molecular chains, making it difficult to form a three-dimensional physical interpenetrating network with polyurethane molecular chains. Its bonding tightness with polyurethane is lower than that in Example 1, and the antibacterial rate of the fiber is also significantly lower than that in Example 1 after multiple washes.

[0046] The above description is the preferred embodiment of the invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the invention, and these improvements and modifications are also considered to be within the scope of protection of the invention.

Claims

1. A long-lasting antibacterial fiber, characterized in that, The long-lasting antibacterial fiber comprises polyurethane resin and quaternary ammonium salt antibacterial agent in a mass ratio of 100:(1.5-5); The quaternary ammonium salt antibacterial agent is prepared by the following process: Add 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene and alkyl diamine to N,N-dimethylacetamide, stir and react, pour the solution into ethanol, filter, wash the product, and dry to obtain a quaternary ammonium salt antibacterial agent; The long-lasting antibacterial fiber is prepared by the following process: polyurethane resin and quaternary ammonium salt antibacterial agent are added to a mixed solution of N,N-dimethylformamide and tetrahydrofuran, stirred and degassed under vacuum to form a spinning solution, which is then electrospun using an electrospinning machine to obtain the long-lasting antibacterial fiber.

2. The long-lasting antibacterial fiber according to claim 1, characterized in that, The reaction temperature is 130-145℃, and the reaction time is 12-18h.

3. The long-lasting antibacterial fiber according to claim 1, characterized in that, The molar ratio of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene to alkyl diamine is 1:(1.5-1.7).

4. The long-lasting antibacterial fiber according to claim 3, characterized in that, The alkyl diamine is ethylenediamine, 1,3-propanediamine, or 1,4-butanediamine.

5. The long-lasting antibacterial fiber according to claim 3, characterized in that, The preparation process of 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene is as follows: 1,3,5-tris(bromomethyl)benzene and N,N-dimethylglycine methyl ester are added to acetonitrile, heated to 75-80℃, stirred and refluxed for 8-12 hours, rotary evaporated, the product is washed, and recrystallized to obtain 1,3,5-tris(methyl acetate trimethylammonium bromide)benzene.

6. The long-lasting antibacterial fiber according to claim 3, characterized in that, The molar ratio of 1,3,5-tris(bromomethyl)benzene to N,N-dimethylglycine methyl ester is 1:(3.6-4.5).

7. The long-lasting antibacterial fiber according to claim 1, characterized in that, The volume ratio of N,N-dimethylformamide to tetrahydrofuran is 1:(0.8-1).

8. The long-lasting antibacterial fiber according to claim 1, characterized in that, The electrospinning process involves a spinning solution flow rate of 1-4 mL / h, a spinning voltage of 17-22 kV, and a receiving distance of 16-25 cm.

Images