Bacteriostatic silk fiber and preparation method thereof

Abstract

The application discloses antibacterial silk fibers and a preparation method thereof, and the preparation method comprises the following steps: adding modified monomers and modified nano-ZnO into deionized water, then adding Tween 80, uniformly stirring, and obtaining a modified liquid; putting silk fibers into the modified liquid, then adding ammonium persulfate dropwise, constant-temperature oscillation, cleaning the product with acetone, then cleaning the product with P-P-K O and deionized water, drying, and obtaining the antibacterial silk fibers; the modified monomers and the modified nano-ZnO endow the silk fibers with excellent antibacterial, anti-ultraviolet and anti-aging functions, improve the elasticity and hand feeling of the silk fibers, overcome defects such as poor shrinkage resistance, wrinkle resistance and light resistance, and widen the application range of the silk fibers.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of textiles, in particular to a bacteriostatic silk fiber. BACKGROUND

[0002] Silk is the longest filament fiber in nature that can be directly used as a textile raw material, and the length of a single silk filament is generally between 1200-1500 m. Due to its good mechanical properties, luster, fine and soft fiber, smoothness, and good moisture absorption, it is given the reputation of "Queen of Fibers". Silk is mainly composed of two parts, silk fibroin and sericin, of which silk fibroin protein, accounting for about 70% of the weight of silk, is located in the inner layer of silk and is the main component of silk; sericin protein, accounting for about 25% of the weight of silk, is wrapped outside the silk fibroin protein as a protective layer; in addition, there are impurities such as ash, wax, and fat.

[0003] Silk fibroin is a fibrous protein that provides the main component of the mechanical properties of silk and is the focus of scientific research in the field of silk. Based on the antiparallel folded chain conformation, silk fibroin forms microfibrils with a diameter of about 10-15 nm, 1000 microfibrils form fibrils with a diameter of about 1 μm, and 900-1400 fibrils are arranged along the longitudinal axis to form a single fiber with a diameter of 10-18 μm, i.e. silk fibroin fiber. It is this special structure of silk fibroin fiber that makes silk have a porosity as high as 38%, and silk fabric is light, soft, and has good warmth retention, thermal insulation, and moisture permeability. The cross-sectional shape of silk fibroin fiber is approximately triangular, and the average cross-sectional area is about 80 μm 2 The silk fibroin macromolecule is composed of 18 amino acids, of which 11 are essential amino acids for the human body. Alanine, glycine, and serine account for about 79% of the total weight of silk fibroin, and the molar ratio of the three is 3:2:1. Because the side chains of these three amino acids are small and do not have active groups, they can be arranged into relatively regular segments by the action of oxygen bonds in a certain sequence structure. These segments form beta-sheet structure polypeptides and are mostly located in the crystalline region of silk fibroin. Other amino acids such as histidine, tryptophan, and phenylalanine have larger side chains with active groups, which hinder the dense and orderly arrangement of peptide bonds, so these amino acids are mainly located in the non-crystalline region of silk fibroin. Mulberry silk silk fibroin is composed of crystalline and amorphous parts, with a crystallinity of about 50-60%. It is generally believed that the conformation of silk fibroin molecules can be divided into two categories, Silk I structure including random coils and alpha helices, and structure in an antiparallel beta-sheet.

[0004] Sericin is a globular protein, and the proportion of polar side chain amino acids in the 18 amino acids that constitute it is higher than that of silk fibroin, among which the contents of glycine, serine and aspartic acid are relatively high. The secondary structure of sericin is mainly trackless coiling, containing part of beta sheet conformation, but almost no alpha helix structure, and the proportion of beta sheet conformation contained in the inner layer silk fibroin of the part close to the silk fibroin is higher than that of the outer layer silk fibroin.

[0005] Silk fibers are widely loved by the public for their comfortable wear, and are often used to make summer intimate apparel, bedding textiles and health care clothing fabrics. When used as intimate apparel, it is easy to breed bacteria due to direct contact with the human body, affecting the physiological health of the human body. Therefore, it is of great significance to modify silk fibers with antibacterial properties.

[0006] At present, antibacterial agents can be divided into three categories: organic antibacterial agents, inorganic antibacterial agents and natural antibacterial agents. Inorganic antibacterial agents use the antibacterial ability of metals such as silver, copper and zinc, and through physical adsorption, ion exchange and other methods, silver, copper, zinc and other metals (or their ions) are fixed on the surface of porous materials such as fluorite and silica gel to make antibacterial agents. Inorganic antibacterial agents have the disadvantages of weak mildew resistance, large addition amount, high cost and easy discoloration. Natural antibacterial agents are generally extracted from natural animals and plants, such as chitosan extracted from crabs and shrimps, which effectively improves the antibacterial performance of cotton and silk. Natural antibacterial agents have the advantages of safety, environmental protection and green, which meet the needs of the times, but they have poor durability, poor heat resistance and relatively small application range. Organic antibacterial agents have the advantages of variety, strong bactericidal ability, low cost and easy availability, such as phenolic ether, phenol, quaternary ammonium salt, organic halogen and imidazole.

[0007] Chinese patent document CN202210646455.5 discloses a method for processing and making bacteriostatic silk quilts, which comprises the following steps: selecting cocoon, boiling cocoon, peeling cocoon, putting on a stretcher, breaking the opening, beating and stirring cotton, mixing, centrifuging, degumming, soaking, heating, drying, stretching, laying silk, forming, and detecting. The silk quilt is soaked in materials such as octyl phenol polyoxyethylene ether, ester quaternary ammonium salt, glycosyl ester, polyethylene glycol fatty acid ester and poly methacrylic acid polyester, so that bacteriostatic elements can be wrapped on the silk, thereby increasing the bacteriostatic effect.

[0008] Most of the existing technologies use antibacterial agents for post-finishing of silk fibers, but the bacteriostatic finishing of silk fibers by post-finishing method has poor durability and is prone to washing. SUMMARY

[0009] In order to solve the problems in the prior art, the present application aims to provide a bacteriostatic silk fiber, which has excellent bacteriostatic, anti-ultraviolet and anti-aging functions, improves the elasticity and hand feeling of the silk fiber, overcomes the defects of poor shrinkage resistance, wrinkle resistance and light resistance, and widens the application range of the silk fiber.

[0010] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0011] A preparation method of the bacteriostatic silk fiber comprises the following steps: adding modified monomers and modified nano-ZnO into deionized water, then adding Tween 80, stirring uniformly to obtain a modified liquid; putting the silk fiber into the modified liquid, then dropping ammonium persulfate, constant-temperature oscillation, washing the product with acetone, then washing with P-P-GO and deionized water, drying to obtain the bacteriostatic silk fiber.

[0012] Preferably, the mass ratio of the modified monomers, the modified nano-ZnO, the Tween 80 and the deionized water is 8-14:6-12:10-20:500; the weight ratio of the silk fiber, the modified liquid and the ammonium persulfate is 1:30-50:0.5-1; the ammonium persulfate is dropped for 20-40 min, and the constant-temperature oscillation condition is oscillation at 80-90℃ for 1-2h.

[0013] Preferably, the preparation method of the modified nano-ZnO comprises the following steps: adding nano-ZnO into a KH570 aqueous solution, stirring uniformly to obtain the modified nano-ZnO.

[0014] Preferably, the concentration of the KH570 aqueous solution is 5-10wt%, the mass ratio of the nano-ZnO and the KH570 aqueous solution is 10:40-50; the stirring condition is stirring reaction at 300-500r / min and 60-70℃ for 6-10h.

[0015] Preferably, the preparation method of the modified monomers comprises the following steps:

[0016] (1) adding N,N-dimethylethylenediamine into a reaction container, continuously passing N2, adding 2-butenoyl chloride and triethylamine, stirring reaction, washing with DMF, rotating evaporation of the product to obtain an intermediate;

[0017] (2) adding the intermediate and bromobutane into tetrahydrofuran, stirring reaction, rotating evaporation of the product to obtain the modified monomers.

[0018] Preferably, in step (1), the mass ratio of N,N-dimethylethylenediamine, 2-butenoyl chloride and triethylamine is 8-10:12-14:0.4-0.7.

[0019] Preferably, in step (1), the stirring reaction condition is reflux reaction at 60-90℃ for 24-36h.

[0020] Preferably, in step (2), the weight ratio of the intermediate and bromobutane is 10:10-12.

[0021] Preferably, in step (2), the stirring reaction condition is 45-65 DEG C for 12-18 h.

[0022] The application also claims a bacteriostatic silk fiber prepared by the preparation method.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] 1) The application provides a bacteriostatic silk fiber, which is grafted and modified by using a modified monomer and a modified nano ZnO under the action of an initiator ammonium persulfate, so that the silk fiber is endowed with excellent antibacterial, ultraviolet-resistant and anti-aging functions; since degumming treatment is not needed, the presence of sericin can effectively protect fibroin and improve the trade weight of silk, improve the elasticity and hand feeling of the silk fiber, overcome the defects of poor shrinkage resistance, wrinkle resistance and light resistance, and broaden the application range of the silk fiber.

[0025] 2) The application provides a modified monomer, which is prepared by introducing a tertiary amine group into an intermediate by acylating N,N-dimethylethylenediamine with 2-butenoyl chloride using triethylamine as a catalyst, and then quaternizing the tertiary amine compound intermediate with bromobutane; the modified monomer can change the permeability of the cell membrane, hinder bacterial metabolism by exuding the contents of the bacterial cells, destroy the activity of enzymes in the cells to make them die, so as to achieve the effects of bacteriostasis and sterilization; grafting the quaternary ammonium salt modified monomer onto the silk fiber makes the loading more firm, which is not easy to be washed out and accumulated on the human body surface, so that the antibacterial effect is more significant and persistent, and the safety is higher.

[0026] 3) The application provides a modified nano ZnO, which is modified by using KH570, can improve the dispersibility of the nanoparticles, is more easily loaded on the silk fiber, and is endowed with an unsaturated bond; grafting the modified nano ZnO onto the silk fiber can make the silk fiber obtain the functions of ultraviolet resistance, antibacterial property and anti-aging; the modified nano ZnO can reduce the transmittance of ultraviolet rays on the surface of the fabric by reflecting, scattering and absorbing the ultraviolet rays, and can also delay the photooxidation, thermal degradation and hydrolysis of the fiber to play an anti-aging role; the active oxygen and hydroxyl radicals generated by the nano ZnO under visible light can kill microorganisms, but the antibacterial activity is not high; grafting the nano ZnO onto the silk fiber can effectively improve the antibacterial stability of the fiber, and the modified monomer and the nano ZnO can synergistically improve the bacteriostatic property of the silk fiber. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some schematic diagrams of the embodiments of the present application, and therefore should not be regarded as a limitation to the scope. Other related drawings can also be obtained by those skilled in the art without any creative effort.

[0028] Figure 1 The preparation process of the modified monomer provided by the present application. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present application more clear, the following will further describe the present application in combination with the embodiments. Of course, the specific embodiments described herein are only used to explain the present application, and should not be regarded as a limitation to the present application.

[0030] Unless otherwise specified, the chemical reagents and materials in the present application are purchased through market channels or synthesized by raw materials purchased through market channels.

[0031] Silk is purchased from Suzhou Sirui Bao Biological Technology Co., Ltd., with a diameter of 103.28 μm;

[0032] Nanometer ZnO is purchased from Jiangsu Nanchun Technology Co., Ltd., with a particle size of 82-110 nm.

[0033] The following will further describe the present application through specific embodiments.

[0034] Embodiment 1

[0035] A preparation method of bacteriostatic silk fiber, comprising the following steps:

[0036] (1) 10 nanometer ZnO is added into 50 g 8wt% KH570 aqueous solution, and stirred at 400 r / min and 70℃ for 10 h to obtain modified nanometer ZnO;

[0037] (2) 10 g N,N-dimethylethylenediamine is added into a reaction container, N2 is continuously introduced, 14 g 2-butenoyl chloride and 0.7 g triethylamine are added, and reflux reaction is carried out at 90℃ for 36 h. The product is washed with DMF, and unreacted substances are removed by rotary evaporation to obtain an intermediate;

[0038] (3) 10 g of the intermediate and 12 g of bromobutane are added into 60 g of tetrahydrofuran, and stirred at 65℃ for 18 h. Unreacted substances are removed by rotary evaporation to obtain a modified monomer;

[0039] (4) 12g modified monomer, 10g modified nano-ZnO were added into 500g deionized water, then 16g Tween 80 was added, stirred at 8000r / min for 30min to obtain a modified liquid; 10g silk fibers were put into 500g modified liquid, 8g ammonium persulfate was added dropwise under stirring, and the addition of ammonium persulfate was completed in 30min, and the product was oscillated at 85℃ for 1.5h, then washed with acetone, 0.5wt% p-peng plus O and deionized water for 3 times, and dried at 70℃ to obtain antibacterial silk fibers.

[0040] Example 2

[0041] A method for preparing antibacterial silk fibers, comprising the following steps:

[0042] (1) 10nm ZnO was added into 40g 8wt% KH570 aqueous solution, stirred at 400r / min and 60℃ for 6-10h to obtain modified nano-ZnO;

[0043] (2) 8g N,N-dimethyl ethylenediamine was added into a reaction vessel, N2 was continuously introduced, 12g 2-butenoyl chloride and 0.4g triethylamine were added, and the reaction was carried out at 60℃ under reflux for 24h, then the product was washed with DMF, and the unreacted substances were removed by rotary evaporation to obtain an intermediate;

[0044] (3) 10g intermediate, 10g bromobutane were added into 60g tetrahydrofuran, stirred at 45℃ for 12h, and the unreacted substances were removed by rotary evaporation to obtain a modified monomer;

[0045] (4) 12g modified monomer, 10g modified nano-ZnO were added into 500g deionized water, then 16g Tween 80 was added, stirred at 8000r / min for 30min to obtain a modified liquid; 10g silk fibers were put into 500g modified liquid, 8g ammonium persulfate was added dropwise under stirring, and the addition of ammonium persulfate was completed in 30min, and the product was oscillated at 85℃ for 1.5h, then washed with acetone, 0.5wt% p-peng plus O and deionized water for 3 times, and dried at 70℃ to obtain antibacterial silk fibers.

[0046] Example 3

[0047] A method for preparing antibacterial silk fibers, comprising the following steps:

[0048] (1) 10nm ZnO was added into 45g 8wt% KH570 aqueous solution, stirred at 400r / min and 65℃ for 7h to obtain modified nano-ZnO;

[0049] (2) 10 g of N,N-dimethylethylenediamine was added to a reaction vessel, N2 was continuously introduced, 13 g of 2-butenoyl chloride and 0.6 g of triethylamine were added, and the reaction was carried out at 80°C for 32 h. The product was washed with DMF, and the unreacted substance was removed by rotary evaporation to obtain an intermediate;

[0050] (3) 10 g of the intermediate and 12 g of bromobutane were added to 60 g of tetrahydrofuran, and the reaction was carried out at 60°C for 16 h. The unreacted substance was removed by rotary evaporation to obtain a modified monomer;

[0051] (4) 12 g of the modified monomer and 10 g of the modified nano-ZnO were added to 500 g of deionized water, and then 16 g of Tween 80 was added. The mixture was stirred at 8000 r / min for 30 min to obtain a modified liquid. 10 g of silk fibers was put into 500 g of the modified liquid, and 8 g of ammonium persulfate was added dropwise under stirring. The addition of ammonium persulfate was completed in 30 min, and the mixture was oscillated at 85°C for 1.5 h. The product was washed with acetone, and then washed with 0.5 wt% of Pingpingka O and deionized water for 3 times. The mixture was dried at 70°C to obtain antibacterial silk fibers.

[0052] Example 4

[0053] A method for preparing antibacterial silk fibers comprises the following steps:

[0054] (1) 10 nm ZnO was added to 50 g of 8 wt% KH570 aqueous solution, and the mixture was stirred at 400 r / min and 70°C for 9 h to obtain modified nano-ZnO;

[0055] (2) 10 g of N,N-dimethylethylenediamine was added to a reaction vessel, N2 was continuously introduced, 13 g of 2-butenoyl chloride and 0.6 g of triethylamine were added, and the reaction was carried out at 80°C for 32 h. The product was washed with DMF, and the unreacted substance was removed by rotary evaporation to obtain an intermediate;

[0056] (3) 10 g of the intermediate and 12 g of bromobutane were added to 60 g of tetrahydrofuran, and the reaction was carried out at 60°C for 16 h. The unreacted substance was removed by rotary evaporation to obtain a modified monomer;

[0057] (4) 12 g of the modified monomer and 10 g of the modified nano-ZnO were added to 500 g of deionized water, and then 16 g of Tween 80 was added. The mixture was stirred at 8000 r / min for 30 min to obtain a modified liquid. 10 g of silk fibers was put into 500 g of the modified liquid, and 8 g of ammonium persulfate was added dropwise under stirring. The addition of ammonium persulfate was completed in 30 min, and the mixture was oscillated at 85°C for 1.5 h. The product was washed with acetone, and then washed with 0.5 wt% of Pingpingka O and deionized water for 3 times. The mixture was dried at 70°C to obtain antibacterial silk fibers.

[0058] Comparative Example 1

[0059] A method for preparing bacteriostatic silk fiber, comprising the following steps:

[0060] (1) 10 g of N, N-dimethyl ethylenediamine is added to a reaction container, N2 is continuously introduced, 14 g of 2-butenoyl chloride and 0.7 g of triethylamine are added, and reflux reaction is carried out at 90°C for 36 h; the product is washed with DMF, and unreacted substances are removed by rotary evaporation to obtain an intermediate;

[0061] (2) 10 g of the intermediate and 12 g of bromobutane are added to 60 g of tetrahydrofuran, and stirring reaction is carried out at 65°C for 18 h; unreacted substances are removed by rotary evaporation to obtain a modified monomer;

[0062] (3) 12 g of the modified monomer is added to 500 g of deionized water, and then 16 g of Tween 80 is added; stirring is carried out at 8000 r / min for 30 min to obtain a modified liquid; 10 g of silk fiber is put into 500 g of the modified liquid, and 8 g of ammonium persulfate is added dropwise under stirring; the dropwise addition of ammonium persulfate is completed in 30 min; constant temperature oscillation is carried out at 85°C for 1.5 h; the product is washed with acetone, and then washed with 0.5 wt% of Pingpingka O and deionized water for 3 times; drying is carried out at 70°C to obtain bacteriostatic silk fiber.

[0063] Comparative Example 2

[0064] A method for preparing bacteriostatic silk fiber, comprising the following steps:

[0065] (1) 10 nm ZnO is added to 50 g of 8 wt% KH570 aqueous solution, and stirring reaction is carried out at 400 r / min and 70°C for 10 h to obtain modified nano-ZnO;

[0066] (2) 10 g of the modified nano-ZnO is added to 500 g of deionized water, and then 16 g of Tween 80 is added; stirring is carried out at 8000 r / min for 30 min to obtain a modified liquid; 10 g of silk fiber is put into 500 g of the modified liquid, and 8 g of ammonium persulfate is added dropwise under stirring; the dropwise addition of ammonium persulfate is completed in 30 min; constant temperature oscillation is carried out at 85°C for 1.5 h; the product is washed with acetone, and then washed with 0.5 wt% of Pingpingka O and deionized water for 3 times; drying is carried out at 70°C to obtain bacteriostatic silk fiber.

[0067] The mechanical properties of the fibers were tested by using a universal material testing machine Instron 5565, with the parameter settings of a clamp distance of 10 mm, a tensile rate of 10 mm / min, and testing under constant temperature and humidity conditions of 20°C and 65% humidity, 5 parallel samples were tested for each sample; the ultraviolet light transmittance of the silk fibers was tested according to GB / T 18830-2009 "Evaluation of Anti-UV Performance of Textiles"; the silk fibers were washed in water at 50°C for 50 times (20 min / time), then washed in cold water for 5 min, dried, and then the antibacterial performance was tested according to the shake flask method in FZ / T 73023-2006 "Antibacterial Knitted Fabrics", and the specific data are shown in Table 1.

[0068] Table 1: Performance test data of silk fibers

[0069]

[0070] The above merely describes the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacements or changes to the technical solutions and inventive concepts of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for preparing bacteriostatic silk fibers, characterized by, It comprises the following steps: adding modified monomer and modified nano-ZnO into deionized water, then adding Tween 80, stirring uniformly to obtain a modified liquid; putting silk fibers into the modified liquid, then adding ammonium persulfate dropwise, constant temperature oscillation, washing the product with acetone, then washing with P-P-KO and deionized water, drying to obtain antibacterial silk fibers; The preparation method of the modified nano-ZnO comprises the following steps: adding nano-ZnO into a KH570 aqueous solution, stirring uniformly to obtain modified nano-ZnO. The preparation method of the modified monomer comprises the following steps: (1) adding N,N-dimethyl ethylenediamine into a reaction container, continuously passing N2, adding 2-butenoyl chloride and triethylamine, stirring reaction, washing with DMF, rotating evaporation of the product to obtain an intermediate; (2) adding the intermediate and bromobutane into tetrahydrofuran, stirring reaction, rotating evaporation of the product to obtain the modified monomer.

2. The production method according to claim 1, characterized by, The mass ratio of the modified monomer, modified nano-ZnO, Tween 80 and deionized water is 8-14:6-12:10-20:500; the weight ratio of the silk fibers, modified liquid and ammonium persulfate is 1:30-50:0.5-1; ammonium persulfate is added dropwise for 20-40 min, and the constant temperature oscillation condition is oscillation at 80-90℃ for 1-2h.

3. The preparation method according to claim 1, characterized in that, The concentration of the KH570 aqueous solution is 5-10wt%, and the mass ratio of nano-ZnO to the KH570 aqueous solution is 10:40-50; the stirring condition is stirring reaction at 300-500r / min and 60-70℃ for 6-10h.

4. The method of claim 1, wherein, In step (1), the mass ratio of N,N-dimethyl ethylenediamine, 2-butenoyl chloride and triethylamine is 8-10:12-14:0.4-0.

7.

5. The preparation method according to claim 1, characterized in that, In step (1), the stirring reaction condition is reflux reaction at 60-90℃ for 24-36h.

6. The method of claim 1, wherein, In step (2), the weight ratio of the intermediate to bromobutane is 10:10-12.

7. The preparation method according to claim 1, characterized in that, In step (2), the stirring reaction condition is reaction at 45-65℃ for 12-18h. 8.An antibacterial silk fiber prepared by the preparation method of any one of claims 1-7.

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