Antibacterial polyester fiber and preparation method thereof

Abstract

The present invention relates to the technical field of polyester fiber, and discloses an antibacterial polyester fiber and a preparation method thereof, a quaternary ammonium salt-ester polymer modified chitosan, and a terephthalate structural unit similar to polyethylene terephthalate is contained in its molecular chain, so that the two have uniform and good interface compatibility, and after melt spinning, the quaternary ammonium salt-ester polymer modified chitosan can be evenly dispersed in the polyester fiber matrix, and the breaking strength of the polyester fiber will not be affected. The quaternary ammonium salt-ester polymer modified chitosan contains a hydrophilic carboxymethyl chitosan structure and a quaternary ammonium salt hydrophilic cationic group, which can effectively improve the hydrophilicity and moisture regain of polyester fiber and its fabric. And it contains a quaternary ammonium salt antibacterial group, which is evenly distributed in the polyester fiber matrix, and the antibacterial performance of the polyester fiber fabric is significantly improved.

Description

Technical Field

[0001] The invention relates to the technical field of polyester fibers, in particular to an antibacterial polyester fiber and a preparation method thereof. Background Art

[0002] Fibers are widely used in reinforcing materials, textiles, clothing fabrics, etc. Among them, polyester fibers have good wrinkle resistance, resilience, wear resistance and other properties, and are widely used; however, polyester fibers and their textile fabrics have poor hydrophilicity and hygroscopicity and do not have good antibacterial properties. In order to expand the application of polyester fibers in antibacterial and medical and sanitary materials, it is necessary to improve the antibacterial, hydrophilic, hygroscopic and breaking strength properties of polyester fibers.

[0003] Chitosan has good antibacterial properties, good biocompatibility, non-toxic and pollution-free, and is widely used in fiber materials and textile fabrics. Compared with ordinary chitosan, quaternary ammonium salt chitosan has better antibacterial properties. Chitosan can be blended with cotton fiber, silk, polyester, etc. to obtain composite fiber materials with excellent performance. However, the compatibility of chitosan and polyester is poor. After spinning, chitosan will produce phase separation in the fiber, affecting the performance of the fiber. Summary of the invention

[0004] The technical problem solved by the invention is to prepare a polyester fiber with high hydrophilic moisture absorption rate, good antibacterial property and high breaking strength.

[0005] The technical solution provided by the present invention is:

[0006] A method for preparing antibacterial polyester fiber: step (1): adding N,N-dimethylformamide, carboxymethyl chitosan, and terephthalate-N-methylhydroxyethylamine into a reaction container, stirring evenly and introducing nitrogen, adding hexamethylene diisocyanate and dibutyltin dilaurate, controlling the reaction temperature to 70-85°C and the reaction time to 2-4 hours, pouring the solution into ethanol for precipitation after the reaction, filtering, and washing with water and ethanol to obtain tertiary amine-ester polymer modified chitosan.

[0007] The structural formula of terephthalate-N-methylhydroxyethylamine is:

[0008]

[0009] Step (2): Add N,N-dimethylformamide, tertiary amine-ester polymer modified chitosan and alkyl bromide compound into a reaction container, pour the solution into ethanol for precipitation after the reaction, filter and wash with ethanol to obtain quaternary ammonium salt-ester polymer modified chitosan.

[0010] Step (3): melt-blending quaternary ammonium salt-ester polymer modified chitosan and polyethylene terephthalate in a twin-screw extruder, extruding and granulating the granules, and then spinning the granules in a melt spinning machine; the obtained fibers are stretched in a stretching machine to obtain antibacterial polyester fibers.

[0011] Wherein, in step (1), the ratio of carboxymethyl chitosan, terephthalate-N-methylhydroxyethylamine, hexamethylene diisocyanate and dibutyltin dilaurate is 1g:(2-10)g:(0.8-4)g:(0.003-0.012)g.

[0012] Wherein, in step (2), the ratio of tertiary amine-ester polymer modified chitosan to alkyl bromide compound is 1g:(1.4-8.5)g; and the alkyl bromide compound is any one of 1-bromododecane, 1-bromodridecane, 1-bromodotetradecane, 1-bromodopentadecane and 1-bromodhexadecane.

[0013] Wherein, in step (2), the reaction temperature is controlled to be 120-140° C., and the reaction time is 36-48 hours.

[0014] Wherein, in step (3), the ratio of quaternary ammonium salt-ester polymer modified chitosan to polyethylene terephthalate is (0.01-0.12) g:1.

[0015] In step (3), the screw temperature of the twin-screw extruder is 230-240°C, and the screw speed is set to 25-40r / min; the spinning temperature of the melt spinning machine is controlled to be 265-280°C, and the spinning rate is 500-750m / min; the hot plate temperature of the stretching machine is controlled to be 80-90°C, and the drafting multiple is controlled to be 2.5-3 times.

[0016] Among them, the preparation method of terephthalate-N-methylhydroxyethylamine is: add acetonitrile solvent, terephthalate ethyl bromide, N-methyl-2-hydroxyethylamine, and a catalyst into a reaction container, react at 15-25° C. for 2-4 hours, concentrate the solvent, and recrystallize the product in ethyl acetate to obtain terephthalate-N-methylhydroxyethylamine.

[0017] The ratio of terephthalate ethyl bromide, N-methyl-2-hydroxyethylamine and catalyst is 1g: (0.42-0.55)g: (0.58-0.66)g. The catalyst is triethylamine or N,N-diisopropylethylamine.

[0018] The technical effect of the invention is that carboxymethyl chitosan is used as a polymerization reaction site, terephthalate-N-methylhydroxyethylamine containing dihydroxy is used to carry out an in-situ graft polymerization reaction with hexamethylene diisocyanate in the carboxymethyl chitosan molecular chain to obtain tertiary amine-ester polymer modified chitosan, and then the introduced tertiary amine group is subjected to a quaternization reaction with an alkyl bromide compound to obtain a quaternary ammonium salt-ester polymer modified chitosan, wherein the molecular chain of the chitosan contains a terephthalate structural unit similar to polyethylene terephthalate. This makes the interface compatibility between the two even and good. After melt spinning, the quaternary ammonium salt-ester polymer modified chitosan can be evenly dispersed in the polyester fiber matrix without affecting the breaking strength of the polyester fiber.

[0019] The quaternary ammonium salt-ester polymer modified chitosan contains a hydrophilic carboxymethyl chitosan structure and a quaternary ammonium salt hydrophilic cationic group, which can effectively improve the hydrophilicity of polyester fibers and their fabrics, and significantly improve the moisture regain. It also contains quaternary ammonium salt antibacterial groups, which are evenly distributed in the polyester fiber matrix, significantly improving the antibacterial properties of polyester fiber fabrics against Escherichia coli and Staphylococcus aureus. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the reaction diagram of terephthalate-N-methylhydroxyethylamine. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The main raw material of the invention is carboxymethyl chitosan, CAS No. 83512-85-0.

[0023] N-Methyl-2-hydroxyethylamine, CAS No. 109-83-1.

[0024] 1-Bromododecane, CAS No. 143-15-7.

[0025] Hexamethylene diisocyanate, CAS No. 822-06-0.

[0026] Add 14 mL of 2-bromoethanol, 10 g of terephthaloyl chloride, and 28 mL of triethylamine to 50 mL of dichloromethane at 0°C, heat to 25°C, react for 20 hours, extract with 5% potassium carbonate solution and deionized water in turn, dry the organic phase, and concentrate to obtain terephthalate ethyl bromide, the structural formula of which is:

[0027] Example 1

[0028] Add 30 mL of acetonitrile solvent, 3 g of terephthalate ethyl bromide, 1.65 g of N-methyl-2-hydroxyethylamine, and 1.74 g of catalyst triethylamine into a reaction container, react at 20° C. for 4 h, concentrate the solvent, and recrystallize the product from ethyl acetate to obtain terephthalate-N-methylhydroxyethylamine.

[0029] Add 30 mL of N,N-dimethylformamide, 0.5 g of carboxymethyl chitosan, and 1 g of terephthalate-N-methylhydroxyethylamine into the reaction container, stir evenly and then introduce nitrogen, add 0.4 g of hexamethylene diisocyanate and 1.5 mg of dibutyltin dilaurate, control the reaction temperature to 70 ° C, and the reaction time to 4 h. After the reaction, pour the solution into ethanol for precipitation, filter, and wash with water and ethanol to obtain tertiary amine-ester polymer modified chitosan.

[0030] Add N,N-dimethylformamide, 1 g of tertiary amine-ester polymer modified chitosan, and 1.4 g of 1-bromodecane into a 40 mL reaction container, and react at 130° C. for 36 h. After the reaction, pour the solution into ethanol for precipitation, filter, and wash with ethanol to obtain quaternary ammonium salt-ester polymer modified chitosan.

[0031] 5g of quaternary ammonium salt-ester polymer modified chitosan and 500g of polyethylene terephthalate were melt-blended in a twin-screw extruder with a screw temperature of 230°C and a screw speed of 40r / min, extruded into granules, and then the granules were spun in a melt spinning machine with the spinning temperature controlled at 270°C and the spinning rate controlled at 600m / min; the obtained fiber was stretched in a stretching machine with the hot plate temperature controlled at 80°C and the drafting multiple controlled at 3 times to obtain antibacterial polyester fiber.

[0032] Example 2

[0033] Add 30 mL of acetonitrile solvent, 3 g of terephthalate ethyl bromide, 1.26 g of N-methyl-2-hydroxyethylamine, and 1.98 g of catalyst N,N-diisopropylethylamine into a reaction container, react at 25° C. for 2 h, concentrate the solvent, and recrystallize the product from ethyl acetate to obtain terephthalate-N-methylhydroxyethylamine.

[0034] Add 50 mL of N,N-dimethylformamide, 0.5 g of carboxymethyl chitosan, and 3 g of terephthalate-N-methylhydroxyethylamine into the reaction container, stir evenly and introduce nitrogen, add 1.8 g of hexamethylene diisocyanate and 3.8 mg of dibutyltin dilaurate, control the reaction temperature to 70 ° C, and the time to 4 h. After the reaction, pour the solution into ethanol for precipitation, filter, wash with water and ethanol to obtain tertiary amine-ester polymer modified chitosan.

[0035] Add N,N-dimethylformamide, 1 g of tertiary amine-ester polymer modified chitosan, and 5.2 g of 1-bromodecane into a 40 mL reaction container, and react at 120° C. for 48 h. After the reaction, pour the solution into ethanol for precipitation, filter, and wash with ethanol to obtain quaternary ammonium salt-ester polymer modified chitosan.

[0036] 30g of quaternary ammonium salt-ester polymer modified chitosan and 500g of polyethylene terephthalate are melt-blended in a twin-screw extruder with a screw temperature of 230°C and a screw speed of 40r / min, and extruded into granules. The granules are then spun in a melt spinning machine with the spinning temperature controlled at 270°C and the spinning rate controlled at 600m / min. The obtained fiber is stretched in a stretching machine with the hot plate temperature controlled at 80°C and the drafting multiple controlled at 3 times to obtain antibacterial polyester fiber.

[0037] Example 3

[0038] Add 50 mL of acetonitrile solvent, 3 g of terephthalate ethyl bromide, 1.42 g of N-methyl-2-hydroxyethylamine, and 1.74 g of catalyst triethylamine into a reaction container, react at 15° C. for 4 h, concentrate the solvent, and recrystallize the product from ethyl acetate to obtain terephthalate-N-methylhydroxyethylamine.

[0039] Add 50 mL of N,N-dimethylformamide, 0.5 g of carboxymethyl chitosan, and 5 g of terephthalate-N-methylhydroxyethylamine into the reaction container, stir evenly and then introduce nitrogen, add 2 g of hexamethylene diisocyanate and 6 mg of dibutyltin dilaurate, control the reaction temperature to 85 ° C, and the reaction time to 2 h. After the reaction, pour the solution into ethanol for precipitation, filter, and wash with water and ethanol to obtain tertiary amine-ester polymer modified chitosan.

[0040] Add N,N-dimethylformamide, 1 g of tertiary amine-ester polymer modified chitosan, and 8.5 g of 1-bromodecane into a 60 mL reaction container, and react at 140° C. for 36 h. After the reaction, pour the solution into ethanol for precipitation, filter, and wash with ethanol to obtain quaternary ammonium salt-ester polymer modified chitosan.

[0041] 60g of quaternary ammonium salt-ester polymer modified chitosan and 500g of polyethylene terephthalate are melt-blended in a twin-screw extruder with a screw temperature of 230°C and a screw speed of 40r / min, and extruded into granules. The granules are then spun in a melt spinning machine with the spinning temperature controlled at 270°C and the spinning rate controlled at 600m / min. The obtained fiber is stretched in a stretching machine with the hot plate temperature controlled at 80°C and the drafting multiple controlled at 3 times to obtain antibacterial polyester fiber.

[0042] Comparative Example 1

[0043] 5g of carboxymethyl chitosan and 500g of polyethylene terephthalate were melt-blended in a twin-screw extruder with a screw temperature of 230°C and a screw speed of 40r / min, and extruded into granules. The granules were then spun in a melt spinning machine with the spinning temperature controlled at 270°C and the spinning rate controlled at 600m / min. The obtained fiber was stretched in a stretching machine with the hot plate temperature controlled at 80°C and the drafting multiple controlled at 3 times to obtain polyester fiber.

[0044] Comparative Example 2

[0045] Add 30 mL of N,N-dimethylformamide and 1 g of terephthalate-N-methylhydroxyethylamine into a reaction container, stir evenly and introduce nitrogen, add 0.4 g of hexamethylene diisocyanate and 1.5 mg of dibutyltin dilaurate, control the reaction temperature to 70° C. and the reaction time to 4 h, pour the solution into ethanol for precipitation after the reaction, filter, and wash with water and ethanol to obtain a tertiary amine-ester polymer;

[0046] Add N,N-dimethylformamide, 1 g of tertiary amine-ester polymer, and 1.4 g of 1-bromodecane into a 40 mL reaction container, and react at 130° C. for 36 h. After the reaction, pour the solution into ethanol for precipitation, filter, and wash with ethanol to obtain a quaternary ammonium salt-ester polymer;

[0047] 5 g of quaternary ammonium salt-ester polymer and 500 g of polyethylene terephthalate were melt-blended in a twin-screw extruder with a screw temperature of 230° C. and a screw speed of 40 r / min, and extruded into granules. The granules were then spun in a melt spinning machine with the spinning temperature controlled at 270° C. and the spinning rate controlled at 600 m / min. The obtained fiber was stretched in a stretching machine with the hot plate temperature controlled at 80° C. and the drafting multiple controlled at 3 times to obtain polyester fiber.

[0048] Comparative Example 3

[0049] Add 30 mL of N,N-dimethylformamide, 0.5 g of carboxymethyl chitosan, and 1 g of terephthalate-N-methylhydroxyethylamine into the reaction container, stir evenly and then introduce nitrogen, add 0.4 g of hexamethylene diisocyanate and 1.5 mg of dibutyltin dilaurate, control the reaction temperature to 70 ° C, and the reaction time to 4 h. After the reaction, pour the solution into ethanol for precipitation, filter, and wash with water and ethanol to obtain tertiary amine-ester polymer modified chitosan.

[0050] 5g of tertiary amine-ester polymer modified chitosan and 500g of polyethylene terephthalate were melt-blended in a twin-screw extruder with a screw temperature of 230°C and a screw speed of 40r / min, extruded into granules, and then the granules were spun in a melt spinning machine with the spinning temperature controlled at 270°C and the spinning rate controlled at 600m / min; the obtained fiber was stretched in a stretching machine with the hot plate temperature controlled at 80°C and the drafting multiple controlled at 3 times to obtain polyester fiber.

[0051] Comparative Example 4

[0052] Polyethylene terephthalate is melt-blended in a twin-screw extruder with a screw temperature of 230°C and a screw speed of 40 r / min, extruded into granules, and then the granules are spun in a melt spinning machine with the spinning temperature controlled at 270°C and the spinning rate controlled at 600 m / min; the obtained fiber is stretched in a stretching machine with the hot plate temperature controlled at 80°C and the drafting multiple controlled at 3 times to obtain polyester fiber.

[0053] The breaking strength of polyester fiber was tested by electron microscope. The tensile speed was 10 mm / min, the holding distance was 10 cm, the pre-tension was 0.2 cN, and the test was repeated 50 times to take the average value.

[0054]

[0055]

[0056] Example 1-3 uses carboxymethyl chitosan as the polymerization reaction site, terephthalate-N-methylhydroxyethylamine The chitosan is modified by grafting with hexamethylene diisocyanate in the molecular chain of carboxymethyl chitosan to obtain tertiary amine-ester polymer-modified chitosan. The introduced tertiary amine group is then quaternized with an alkyl bromide compound to obtain a quaternary ammonium salt-ester polymer-modified chitosan, whose molecular chain contains a terephthalate structural unit similar to polyethylene terephthalate. The two have good interface compatibility. After melt spinning, the quaternary ammonium salt-ester polymer modified chitosan can be evenly dispersed in the polyester fiber matrix without affecting the breaking strength of the polyester fiber.

[0057] In Comparative Example 1, only carboxymethyl chitosan was added, which had poor compatibility with polyethylene terephthalate. After melt spinning, chitosan produced phase separation in the polyester fiber matrix due to interface incompatibility, thereby reducing the breaking strength of the polyester fiber.

[0058] The polyester fiber is woven into a fabric and tested according to the method of GB / T 9995 to test the moisture regain W of the fabric. W = (G-G0) / G0×100%, G is the mass of the sample before moisture absorption and drying, and G0 is the mass of the sample after drying.

[0059] Moisture regain (%) Example 1 2.69 Example 2 4.01 Example 3 4.72 Comparative Example 1 2.64 Comparative Example 2 0.31 Comparative Example 3 1.79 Comparative Example 4 0.36

[0060] The quaternary ammonium salt-ester polymer modified chitosan prepared in Examples 1-3 has good compatibility with polyethylene terephthalate and is evenly dispersed in the composite polyester fiber matrix after spinning. It contains a hydrophilic carboxymethyl chitosan structure and a quaternary ammonium salt hydrophilic cationic group, which can effectively improve the hydrophilicity of polyester fibers and their fabrics, and significantly improve the moisture regain.

[0061] In comparative example 1, carboxymethyl chitosan was added, and in comparative example 3, tertiary amine-ester polymer-modified chitosan containing carboxymethyl chitosan was added, and the hydrophilicity and moisture regain of the polyester fiber fabric were also improved to a certain extent.

[0062] According to CB / T 20944.3-2008 "Evaluation of Antibacterial Properties of Textiles Part 3: Oscillating Bottle Method", the antibacterial rate of polyester fiber fabrics against Escherichia coli and Staphylococcus aureus was tested, with the fabrics woven from the polyester fibers of Examples 1-3 and Comparative Examples 1-3 as the experimental group, and the polyester fibers of Comparative Example 4 as the blank group.

[0063]

[0064]

[0065] The quaternary ammonium salt-ester polymer modified chitosan prepared in Examples 1-3 and the quaternary ammonium salt-ester polymer of Comparative Example 2 have good compatibility with polyethylene terephthalate, and contain quaternary ammonium salt antibacterial groups, which are evenly distributed in the polyester fiber matrix, significantly improving the antibacterial properties of polyester fiber fabrics against Escherichia coli and Staphylococcus aureus.

[0066] In comparative example 1, only carboxymethyl chitosan was added, and the polyester fiber fabric had no antibacterial properties. In comparative example 2, tertiary amine-ester polymer-modified chitosan was added, which did not contain quaternary ammonium salt antibacterial groups, and the polyester fiber fabric had almost no antibacterial properties.

Claims

1. A method for preparing antibacterial polyester fiber, characterized in that: The steps include: Step (1): Add N,N-dimethylformamide, carboxymethyl chitosan, and terephthaloyl (formate-N-methylhydroxyethylamine) into a reaction container, stir evenly, introduce nitrogen, add hexamethylene diisocyanate and dibutyltin dilaurate, pour the solution into ethanol for precipitation after reaction, filter, and wash with water and ethanol to obtain tertiary amine-ester polymer modified chitosan; The structural formula of the terephthalate (formate-N-methylhydroxyethylamine) is: ； Step (2): adding N,N-dimethylformamide, tertiary amine-ester polymer modified chitosan, and alkyl bromide compound into a reaction container, and after the reaction, pouring the solution into ethanol for precipitation, filtering, and washing with ethanol to obtain quaternary ammonium salt-ester polymer modified chitosan; Step (3): melt-blending the quaternary ammonium salt-ester polymer modified chitosan and polyethylene terephthalate in a twin-screw extruder, extruding and granulating the pellets, and then spinning the pellets in a melt spinning machine; the obtained fibers are stretched in a stretching machine to obtain antibacterial polyester fibers; In the step (2), the ratio of tertiary amine-ester polymer modified chitosan to alkyl bromide compound is 1 g: (1.4-8.5) g; The alkyl bromide compound is any one of 1-bromododecane, 1-bromodridecane, 1-bromodotetradecane, 1-bromodopentadecane, and 1-bromodhexadecane; The preparation method of terephthalate-N-methylhydroxyethylamine is as follows: acetonitrile solvent, terephthalate-ethyl bromide, N-methyl-2-hydroxyethylamine and a catalyst are added into a reaction container, reacted at 15-25° C. for 2-4 hours, the solvent is concentrated, and the product is recrystallized in ethyl acetate to obtain terephthalate-N-methylhydroxyethylamine.

2. The method for preparing the antibacterial polyester fiber according to claim 1, characterized in that: In the step (1), the ratio of carboxymethyl chitosan, terephthalate-N-methylhydroxyethylamine, hexamethylene diisocyanate and dibutyltin dilaurate is 1 g: (2-10) g: (0.8-4) g: (0.003-0.012) g.

3. The method for preparing the antibacterial polyester fiber according to claim 1, characterized in that: In the step (1), the reaction temperature is controlled to be 70-85°C and the reaction time is 2-4 hours.

4. The method for preparing the antibacterial polyester fiber according to claim 1, characterized in that: In the step (2), the reaction temperature is controlled to be 120-140° C. and the reaction time is 36-48 hours.

5. The method for preparing the antibacterial polyester fiber according to claim 1, characterized in that: In the step (3), the ratio of quaternary ammonium salt-ester polymer modified chitosan to polyethylene terephthalate is (0.01-0.12) g:1 g.

6. The method for preparing the antibacterial polyester fiber according to claim 1, characterized in that: In the step (3), the screw temperature of the twin-screw extruder is 230-240°C, and the screw speed is set to 25-40 r / min; the spinning temperature of the melt spinning machine is controlled to be 265-280°C, and the spinning rate is 500-750 m / min; the hot plate temperature of the stretching machine is controlled to be 80-90°C, and the drafting multiple is controlled to be 2.5-3 times.

7. The method for preparing the antibacterial polyester fiber according to claim 1, characterized in that: The ratio of terephthalate ethyl bromide, N-methyl-2-hydroxyethylamine and catalyst is 1 g: (0.42-0.55) g: (0.58-0.66) g.

8. The method for preparing the antibacterial polyester fiber according to claim 1, characterized in that: The catalyst is triethylamine or N,N-diisopropylethylamine.

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