Preparation method of superfine antibacterial fiber

Abstract

The invention discloses a preparation method of superfine antibacterial fibers. According to the scheme, ethyl glycolate reacts with an organic functional group of isocyanate propyl triethoxy siloxane, and a hydrolytic functional group of isocyanate propyl triethoxy siloxane reacts with copper / zinc oxide nanoparticles for surface modification; polyethyleneimine and silver are complexed and coated with chitosan condensed cinnamon Schiff base, and the chitosan Schiff base is combined with a copolymer of isocyanate propyl triethoxy siloxane and ethyl glycolate through hydrogen bonds, so that the two modified particles are compounded to form the composite antibacterial particle. The dispersity of the composite antibacterial particles in a polymer can be improved through modification of chitosan Schiff base, isocyanate propyl triethoxy siloxane and the like, so that the copper / zinc oxide particles and silver are dispersed in fibers more uniformly, copper, zinc oxide, silver and Schiff base are matched for resisting bacteria, the composite particles with the limited structure are outstanding in antibacterial effect, and the antibacterial effect is good. The fiber can have an excellent antibacterial effect by adding a small amount of the antibacterial agent.

Description

Technical Field

[0001] The present invention relates to the field of fiber technology, and in particular to a method for preparing ultrafine antibacterial fiber. Background Art

[0002] PET fiber, also known as polyethylene terephthalate fiber, is commonly referred to as polyester in my country. In recent years, with economic development and improved living standards, people are paying more and more attention to health issues and are becoming increasingly aware of their hygiene. Consequently, textiles with antibacterial and antimicrobial properties have become a research and development hotspot.

[0003] Common improvements include adding inorganic antibacterial agents to spinning polymers. The formed fibers have certain inhibitory and killing effects on bacteria, fungi, etc. Common antibacterial agents include nanosilver, copper, zinc oxide, etc., but they need to be added in large quantities to achieve the required antibacterial properties. If the amount of inorganic antibacterial agent added is too much, it is easy to damage the original performance of the fiber, which needs to be improved. Summary of the Invention

[0004] To solve at least one of the above technical deficiencies, the present invention provides the following technical solutions:

[0005] This application document discloses a method for preparing ultrafine antibacterial fibers, comprising the following steps:

[0006] First, preparation of composite antibacterial particles

[0007] The copper / zinc oxide nanoparticles were surface-modified by reacting ethyl glycolate and isocyanatepropyl triethoxysiloxane to form modified particles 1;

[0008] Chitosan cinnamaldehyde Schiff base is coated with a complex of polyethyleneimine and silver to form modified particles II;

[0009] Compounding the modified particle 1 with the modified particle 2 to form a composite antibacterial particle;

[0010] Second, the composite antibacterial particles are mixed with a polymer and spun to form fibers.

[0011] In this scheme, ethyl glycolate is reacted with the organic functional groups of isocyanatepropyl triethoxysiloxane and the hydrolysis functional groups of isocyanatepropyl triethoxysiloxane are reacted with copper / zinc oxide nanoparticles for surface modification. Polyethyleneimine is used to complex silver and the nanoparticles are coated with chitosan cinnamon Schiff base. The copolymer of chitosan Schiff base and isocyanatepropyl triethoxysiloxane and ethyl glycolate is hydrogen bonded to form composite antibacterial particles. The modification of chitosan Schiff base, isocyanatepropyl triethoxysiloxane, etc. can improve the dispersibility of the composite antibacterial particles in the polymer, thereby making the copper / zinc oxide particles and silver more evenly dispersed in the fiber. The combination of copper, zinc oxide, silver and Schiff base has an outstanding antibacterial effect. The composite particles of this limited configuration can have an excellent antibacterial effect, and a small amount of addition can make the fiber have an excellent antibacterial effect.

[0012] Furthermore, the modified particle 1 is prepared as follows: zinc nitrate, copper nitrate, and water are mixed and citric acid and ammonia water are added in sequence to form a wet gel, and the wet gel is dried and calcined to obtain copper / zinc oxide nanoparticles;

[0013] Ethyl glycolate, isocyanatepropyl triethoxysiloxane and a catalyst are mixed and reacted, copper / zinc oxide nanoparticles are added to the mixture and the pH is adjusted to alkaline, and the reaction is carried out at a temperature of 55-70° C. The obtained reaction product is the modified particle 1.

[0014] For the reaction of isocyanatepropyl triethoxysiloxane, for example, its isocyanate group reacts with the hydroxyl group on ethyl glycolate to form an amide group, and its siloxane group dehydrates and condenses with the hydroxyl group on the surface of copper / zinc oxide nanoparticles to form a covalent bond, thereby surface-modifying the copper / zinc oxide nanoparticles.

[0015] Furthermore, zinc nitrate and copper nitrate are mixed according to a zinc:copper molar ratio range of 1:0.03-0.07; the molar ratio of citric acid to zinc nitrate ranges from 1.2-1.6:1, ammonia water is added to adjust the solution to alkalinity, and the temperature is raised to 75-85°C to react and form a wet gel. The limited amount ratio helps to improve the antibacterial effect.

[0016] Furthermore, the preparation of modified particles 2 is as follows: polyethyleneimine solution is mixed with silver nitrate and a reducing agent is added for reaction, then chitosan cinnamaldehyde Schiff base solution is added, and the Ph is adjusted to 5.0-6.0 for reaction. The resulting reaction product is placed in an alkaline solution and allowed to stand. The particles remaining after solid-liquid separation are modified particles 2. For reducing agents, ascorbic acid is common. Standing in an alkaline solution helps to expand the pores on the chitosan layer and improve the bactericidal effect of silver.

[0017] Furthermore, the alkaline solution is a sodium hydroxide solution with a concentration of 0.03-0.06 mol / L, and the standing time is less than 20 minutes. The standing time is limited to control the degradation degree of chitosan.

[0018] Furthermore, the mass ratio of modified particle 1 to modified particle 2 is 2-4:1, and limiting the ratio helps to improve the antibacterial effect.

[0019] Furthermore, the mass ratio of the composite antibacterial particles to the polymer is 0.3-0.8:100.

[0020] Furthermore, the fibers are in a special shape, such as an octagonal gear shape, which increases the capillary effect on the fiber surface and helps to improve the moisture absorption and air permeability, liquid transmission capacity, etc. of the fibers.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention uses ethyl glycolate and isocyanatepropyl triethoxysiloxane to react on the surface of copper / zinc oxide nanoparticles to form modified particles 1, and chitosan cinnamaldehyde Schiff base is coated with a complex of polyethyleneimine and silver to form modified particles 2. The two modified particles are combined to construct composite antibacterial particles with a special configuration, which has outstanding antibacterial effect and can meet the antibacterial requirements of fibers with a small amount of addition. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is the inhibition zone diagram of Escherichia coli;

[0025] In the figure, E.col i is Escherichia coli. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] A method for preparing ultrafine antibacterial fiber comprises the following steps:

[0029] First, preparation of composite antibacterial particles

[0030] The copper / zinc oxide nanoparticles were surface modified by reacting ethyl glycolate and isocyanatepropyl triethoxysiloxane to form modified particles 1. The specific steps are as follows: zinc nitrate and copper nitrate were mixed according to a zinc:copper molar ratio of 1:0.04, and water 10 times the total mass of the two was added and stirred, and then citric acid was added and stirred for 1 hour. The molar ratio of citric acid to zinc nitrate was 1.3:1. Then, ammonia water (25%) was dropped into the mixture with a pH of 9 and evaporated at 80°C to form a wet gel. The wet gel was placed in a vacuum oven and dried at 100°C for 24 hours to form a dry gel. The dry gel was calcined at 600°C for 3.5 hours and cooled to obtain copper / zinc oxide nanoparticles.

[0031] Ethyl glycolate and isocyanatepropyl triethoxysiloxane were mixed in a molar ratio of 1:1, and a catalyst (dibutyltin dilaurate) was added at a concentration of 2% by mass of isocyanatepropyl triethoxysiloxane. The mixture was stirred at 40°C for 4 hours. The copper / zinc oxide nanoparticles prepared above (accounting for 20% by mass of the mixed solution) were added to the mixed solution and the pH was adjusted to 10 with a sodium hydroxide solution. The mixture was reacted at 60°C for 15 hours. The reaction product was washed with anhydrous ethanol and deionized water, and dried to obtain modified particles.

[0032] Modified particles II were formed by coating a complex of polyethyleneimine and silver with chitosan-cinnamaldehyde Schiff base. The specific steps were as follows: polyethyleneimine solution (0.1 g / ml) and silver nitrate (0.01 mol / L) were mixed in a volume ratio of 1:3, and then water was added according to 1 / 3 of the volume of the mixture. Finally, a reducing agent (ascorbic acid, 0.1 mol / L) with 1 / 5 of the volume of the mixture was added and reacted for 10 minutes. After standing for 3 days, the mixture was filtered with a 0.4 micron filter and the filtrate was used for later use.

[0033] Chitosan cinnamon Schiff base (cinnamaldehyde and chitosan are mixed in a mass ratio of 1:0.6, reacted at 50°C for 6 hours, alkali solution is added dropwise to adjust the pH to 10, and the precipitated flocs are washed, dried and ground to obtain chitosan cinnamon Schiff base) is mixed with cyclohexane, n-hexanol and Triton X-100 to form a chitosan cinnamon Schiff base solution, wherein the volume ratio of cyclohexane, n-hexanol and Triton X-100 is 5:2:2, and the mass ratio of cyclohexane to chitosan cinnamon Schiff base is 40:1. The filtrate with a mass of 2 times that of the chitosan cinnamon Schiff base is added to the chitosan cinnamon Schiff base solution, the pH is adjusted to 6.0, and the reaction is stirred for 2 hours. The product obtained after centrifugal filtration is immersed in sodium hydroxide solution (0.04 mol / L), allowed to stand for 15 minutes, centrifuged and washed to obtain modified particles 2.

[0034] The modified particle 1 prepared above was mixed with anhydrous ethanol 10 times its mass and polyvinylpyrrolidone (accounting for 1 / 5 of the mass of the modified particle 1), and ultrasonically treated for 10 minutes to obtain dispersion 1. The modified particle 2 was mixed with anhydrous ethanol 10 times its mass and polyvinylpyrrolidone (accounting for 1 / 5 of the mass of the modified particle 2) was added, and ultrasonically treated for 10 minutes to obtain dispersion 2. Dispersion 1 and dispersion 2 were mixed (the mass ratio of modified particle 1 to modified particle 2 was 3:1) and stirred for 2 hours, centrifuged and washed with ethanol multiple times to obtain composite antibacterial particles.

[0035] Second, the composite antibacterial particles were mixed with a polymer and spun to form fibers. The polymer was PET, the mass ratio of the composite antibacterial particles to the polymer was 0.4:100, the spinning temperature was 292°C, and the spinneret was octagonal so that the cross-section of the ejected fiber was octagonal.

[0036] Example 2

[0037] A method for preparing ultrafine antibacterial fiber comprises the following steps:

[0038] First, preparation of composite antibacterial particles

[0039] The copper / zinc oxide nanoparticles were surface modified by reacting ethyl glycolate and isocyanatepropyl triethoxysiloxane to form modified particles 1. The specific steps are as follows: zinc nitrate and copper nitrate were mixed according to a zinc:copper molar ratio of 1:0.06, and water 10 times the total mass of the two was added and stirred, and then citric acid was added and stirred for 1 hour. The molar ratio of citric acid to zinc nitrate was 1.5:1. Then, ammonia water (25%) was dropped into the mixture with a pH of 9 and evaporated at 80°C to form a wet gel. The wet gel was placed in a vacuum oven and dried at 100°C for 24 hours to form a dry gel. The dry gel was calcined at 600°C for 4 hours and cooled to obtain copper / zinc oxide nanoparticles.

[0040] Ethyl glycolate and isocyanatepropyl triethoxysiloxane were mixed in a molar ratio of 1:1, and a catalyst (dibutyltin dilaurate) was added at a concentration of 2% by mass of isocyanatepropyl triethoxysiloxane. The mixture was stirred at 40°C for 4 hours. The copper / zinc oxide nanoparticles prepared above (accounting for 20% by mass of the mixed solution) were added to the mixed solution and the pH was adjusted to 10 with a sodium hydroxide solution. The mixture was reacted at 60°C for 15 hours. The reaction product was washed with anhydrous ethanol and deionized water, and dried to obtain modified particles.

[0041] Modified particles II were formed by coating a complex of polyethyleneimine and silver with chitosan-cinnamaldehyde Schiff base. The specific steps were as follows: polyethyleneimine solution (0.1 g / ml) and silver nitrate (0.01 mol / L) were mixed in a volume ratio of 1:3, and then water was added according to 1 / 3 of the volume of the mixture. Finally, a reducing agent (ascorbic acid, 0.1 mol / L) with 1 / 5 of the volume of the mixture was added and reacted for 10 minutes. After standing for 3 days, the mixture was filtered with a 0.4 micron filter and the filtrate was used for later use.

[0042] Chitosan cinnamon Schiff base (cinnamaldehyde and chitosan are mixed in a mass ratio of 1:0.6, reacted at 50°C for 6 hours, alkali solution is added dropwise to adjust the pH to 10, and the precipitated flocs are washed, dried and ground to obtain chitosan cinnamon Schiff base) is mixed with cyclohexane, n-hexanol and Triton X-100 to form a chitosan cinnamon Schiff base solution, wherein the volume ratio of cyclohexane, n-hexanol and Triton X-100 is 5:3:2, and the mass ratio of cyclohexane to chitosan cinnamon Schiff base is 35:1. The filtrate with a mass of 2 times that of the chitosan cinnamon Schiff base is added to the chitosan cinnamon Schiff base solution, the pH is adjusted to 6.0, and the reaction is stirred for 2 hours. After centrifugation and filtration, the obtained product is immersed in sodium hydroxide solution (0.05 mol / L), allowed to stand for 10 minutes, centrifuged and washed to obtain modified particles 2.

[0043] The modified particle 1 prepared above was mixed with anhydrous ethanol 10 times its mass and polyvinylpyrrolidone (accounting for 1 / 5 of the mass of the modified particle 1), and ultrasonically treated for 10 minutes to obtain dispersion 1. The modified particle 2 was mixed with anhydrous ethanol 10 times its mass and polyvinylpyrrolidone (accounting for 1 / 5 of the mass of the modified particle 2) was added, and ultrasonically treated for 10 minutes to obtain dispersion 2. Dispersion 1 and dispersion 2 were mixed (the mass ratio of modified particle 1 to modified particle 2 was 4:1) and stirred for 2 hours, centrifuged and washed with ethanol multiple times to obtain composite antibacterial particles.

[0044] Second, the composite antibacterial particles were mixed with a polymer and spun to form fibers. The polymer was PET, the mass ratio of the composite antibacterial particles to the polymer was 0.6:100, the spinning temperature was 292°C, and the spinneret was octagonal so that the cross-section of the ejected fiber was octagonal.

[0045] Example 3

[0046] A method for preparing ultrafine antibacterial fiber comprises the following steps:

[0047] First, preparation of composite antibacterial particles

[0048] The copper / zinc oxide nanoparticles were surface modified by reacting ethyl glycolate and isocyanatepropyl triethoxysiloxane to form modified particles 1. The specific steps are as follows: zinc nitrate and copper nitrate were mixed according to a zinc:copper molar ratio of 1:0.07, and water 10 times the total mass of the two was added and stirred, and then citric acid was added and stirred for 1 hour. The molar ratio of citric acid to zinc nitrate was 1.3:1. Then, ammonia water (25%) was dropped into the mixture with a pH of 9 and evaporated at 80°C to form a wet gel. The wet gel was placed in a vacuum oven and dried at 100°C for 24 hours to form a dry gel. The dry gel was calcined at 600°C for 3.5 hours and cooled to obtain copper / zinc oxide nanoparticles.

[0049] Ethyl glycolate and isocyanatepropyl triethoxysiloxane were mixed in a molar ratio of 1:1, and a catalyst (dibutyltin dilaurate) was added at a concentration of 2% by mass of isocyanatepropyl triethoxysiloxane. The mixture was stirred at 40°C for 4 hours. The copper / zinc oxide nanoparticles prepared above (accounting for 20% by mass of the mixed solution) were added to the mixed solution and the pH was adjusted to 10 with a sodium hydroxide solution. The mixture was reacted at 60°C for 15 hours. The reaction product was washed with anhydrous ethanol and deionized water, and dried to obtain modified particles.

[0050] Modified particles II were formed by coating a complex of polyethyleneimine and silver with chitosan-cinnamaldehyde Schiff base. The specific steps were as follows: polyethyleneimine solution (0.1 g / ml) and silver nitrate (0.01 mol / L) were mixed in a volume ratio of 1:3, and then water was added according to 1 / 3 of the volume of the mixture. Finally, a reducing agent (ascorbic acid, 0.1 mol / L) with 1 / 5 of the volume of the mixture was added and reacted for 10 minutes. After standing for 3 days, the mixture was filtered with a 0.4 micron filter and the filtrate was used for later use.

[0051] Chitosan cinnamon Schiff base (cinnamaldehyde and chitosan are mixed in a mass ratio of 1:0.6, reacted at 50°C for 6 hours, alkali solution is added dropwise to adjust the pH to 10, and the precipitated flocs are washed, dried and ground to obtain chitosan cinnamon Schiff base) is mixed with cyclohexane, n-hexanol and Triton X-100 to form a chitosan cinnamon Schiff base solution, wherein the volume ratio of cyclohexane, n-hexanol and Triton X-100 is 5:1:2, and the mass ratio of cyclohexane to chitosan cinnamon Schiff base is 30:1. The filtrate with a mass of 2 times that of the chitosan cinnamon Schiff base is added to the chitosan cinnamon Schiff base solution, the pH is adjusted to 6.0, and the reaction is stirred for 2 hours. The product obtained after centrifugal filtration is immersed in sodium hydroxide solution (0.04 mol / L), allowed to stand for 15 minutes, centrifuged and washed to obtain modified particles 2.

[0052] The modified particle 1 prepared above was mixed with anhydrous ethanol 10 times its mass and polyvinylpyrrolidone (accounting for 1 / 4 of the mass of the modified particle 1), and ultrasonically treated for 10 minutes to obtain dispersion 1. The modified particle 2 was mixed with anhydrous ethanol 10 times its mass and polyvinylpyrrolidone (accounting for 1 / 4 of the mass of the modified particle 2) was added, and ultrasonically treated for 10 minutes to obtain dispersion 2. Dispersion 1 and dispersion 2 were mixed (the mass ratio of modified particle 1 to modified particle 2 was 2.5:1) and stirred for 2 hours, centrifuged and washed with ethanol multiple times to obtain composite antibacterial particles.

[0053] Second, the composite antibacterial particles were mixed with a polymer and spun to form fibers. The polymer was PET, the mass ratio of the composite antibacterial particles to the polymer was 0.8:100, the spinning temperature was 292°C, and the spinneret was octagonal so that the cross-section of the ejected fiber was octagonal.

[0054] Comparative Example 1

[0055] Compared with Example 3, the difference is that in this example, there is no step of compounding the modified particles 1 and 2, and the modified particles 1 and 2 are added to the polymer separately.

[0056] Comparative Example 2

[0057] Compared with Example 3, the difference is that in this example, the modified particles are placed in a solution of chitosan-cinnamon Schiff base, the modified particles are coated with chitosan-cinnamon Schiff base to form composite antibacterial particles, and the complex of polyethyleneimine and silver and the composite antibacterial particles are separately added to the polymer.

[0058] The fibers prepared above were woven into cloth and subjected to an oscillation antibacterial test according to the national standard GB / T20944.3-2008. During the test, the test sample was placed in a culture dish inoculated with a bacterial solution and cultured for 24 hours to observe the inhibition zone. Figure 1 The test results are shown in Table 1:

[0059] Table 1: Antibacterial properties

[0060]

[0061] As can be seen from Table 1, the special configuration composite antibacterial particles constructed in the present invention have excellent antibacterial properties, and a small amount of addition can meet the antibacterial requirements of the fiber and reduce the impact on the fiber performance.

[0062] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that do not depart from the principles of the present invention are within the scope of protection of the present invention.

Claims

1. A method for preparing ultrafine antibacterial fiber, characterized in that: The following steps are involved: First, preparation of composite antibacterial particles The copper / zinc oxide nanoparticles were surface-modified by reacting ethyl glycolate and isocyanatepropyl triethoxysiloxane to form modified particles 1; Chitosan cinnamaldehyde Schiff base is coated with a complex of polyethyleneimine and silver to form modified particles II; Compounding the modified particle 1 with the modified particle 2 to form a composite antibacterial particle; Second, the composite antibacterial particles are mixed with a polymer and spun to form fibers.

2. The method for preparing an ultrafine antibacterial fiber according to claim 1, wherein: The modified particles are prepared as follows: zinc nitrate, copper nitrate, and water are mixed, and citric acid and ammonia water are added in sequence to form a wet gel, and the wet gel is dried and calcined to obtain copper / zinc oxide nanoparticles; Ethyl glycolate, isocyanatepropyl triethoxysiloxane and a catalyst are mixed and reacted, copper / zinc oxide nanoparticles are added to the mixture and the pH is adjusted to alkaline, and the reaction is carried out at a temperature of 55-70° C. The obtained reaction product is the modified particle 1.

3. The method for preparing an ultrafine antibacterial fiber according to claim 2, wherein: Zinc nitrate and copper nitrate are mixed in a zinc:copper molar ratio range of 1:0.03-0.07; the molar ratio of citric acid to zinc nitrate is 1.2-1.6:1, ammonia water is added to adjust the solution to alkalinity, and the temperature is raised to 75-85°C to react and form a wet gel.

4. The method for preparing an ultrafine antibacterial fiber according to claim 1, wherein: The preparation of modified particles 2 is as follows: polyethyleneimine solution is mixed with silver nitrate and a reducing agent is added for reaction, then chitosan cinnamaldehyde Schiff base solution is added, and the Ph is adjusted to 5.0-6.0 for reaction. The resulting reaction product is placed in an alkaline solution and allowed to stand. After solid-liquid separation, the remaining particles are modified particles 2.

5. The method for preparing an ultrafine antibacterial fiber according to claim 4, wherein: The alkaline solution is a sodium hydroxide solution with a concentration of 0.03-0.06 mol / L and a standing time of less than 20 minutes.

6. The method for preparing an ultrafine antibacterial fiber according to claim 1, wherein: The mass ratio of the modified particle 1 to the modified particle 2 is 2-4:

1.

7. The method for preparing an ultrafine antibacterial fiber according to claim 1, wherein: The mass ratio of the composite antibacterial particles to the polymer is 0.3-0.8:

100.

8. The method for preparing an ultrafine antibacterial fiber according to claim 1, wherein: The fibers are of special shapes.

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