Antibacterial polyacrylonitrile fiber and preparation method thereof

Abstract

The invention discloses an antibacterial polyacrylonitrile fiber and a preparation method thereof, and belongs to the technical field of antibacterial fibers. Comprising the following raw materials in parts by weight: 18-24 parts of bamboo fibers, 10-15 parts of LiCl powder, 80-100 parts of polyacrylonitrile and 6-18 parts of a synergistic antibacterial agent. The bamboo fiber is added into the prepared polyacrylonitrile fiber and activated, so that the processability of the polyacrylonitrile fiber is improved, and the antibacterial property and the mechanical property of the fiber are enhanced; wherein the synergistic antibacterial agent has the effect of a guanidine antibacterial agent and contains isothiazolinone and quaternary ammonium salt ions, all groups can achieve a synergistic effect, the antibacterial property and the antistatic property of the fiber are remarkably enhanced, and the fiber is stable in performance and resistant to washing; therefore, the prepared polyacrylonitrile fiber is excellent in mechanical property, has stable and efficient antibacterial property and antistatic property, and has important application value in the technical field of antibacterial fibers.

Description

Technical Field

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

[0002] Polyacrylonitrile (PAN) is a polymer compound obtained by polymerization of acrylonitrile monomer. It has a fluffy appearance, soft feel, good light resistance, weather resistance, elasticity and warmth retention, and is known as "artificial wool". Among the raw materials used in wool spinning and artificial fur in my country, polyacrylonitrile occupies the most important position. The excellent properties of polyacrylonitrile make it widely used in three major fields: clothing, apparel, and industry.

[0003] In daily life, people will inevitably come into contact with various bacteria and viruses, some of which are pathogenic, posing a threat and harm to people's lives and health. Therefore, the development of antibacterial polyacrylonitrile fibers has become a hot topic. The conventional preparation methods of existing antibacterial polyacrylonitrile fibers include antibacterial post-treatment, antibacterial agent surface adhesion, and antibacterial agent co-spinning. The polyacrylonitrile fibers prepared by these methods have excellent antibacterial properties, but the disadvantages of the former two are that the antibacterial properties are not long-lasting and are easily washed off after washing; therefore, the most commonly used method is the antibacterial agent co-spinning method, but most commonly used antibacterial agents have poor hydrophilicity and poor compatibility with polyacrylonitrile fibers, making it difficult to fully exert their performance. In addition, polyacrylonitrile fibers have poor antistatic properties and are prone to generate static electricity, leading to pilling. Therefore, it is urgent to solve the above problems to meet higher demands in the field of antibacterial fiber technology. ‌ Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide an antibacterial polyacrylonitrile fiber and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing antibacterial polyacrylonitrile fiber comprises the following steps: A1. N,N-dimethylacetamide was heated to 110-150°C, condensed and refluxed under nitrogen protection, and bamboo fiber was added for activation for 1-2 hours. The reaction system was cooled to 80-100°C, LiCl powder was added and stirred to dissolve for 1-3 hours, and then heating was stopped and stirring was continued until the reaction system cooled to room temperature. Finally, ultrasonic defoaming was performed to obtain an activated bamboo fiber spinning solution. A2. Mix polyacrylonitrile and N,N-dimethylacetamide, and stir continuously until the polyacrylonitrile is completely dissolved, add the activated bamboo fiber spinning solution prepared in step A1 and the synergistic antibacterial agent, mix by ultrasonic oscillation, and then use an electrospinning process to obtain primary fibers, and then obtain antibacterial polyacrylonitrile fibers through drawing, heat setting, winding and collection.

[0006] Furthermore, the raw materials are calculated in parts by weight as follows: 18-24 parts of bamboo fiber, 10-15 parts of LiCl powder, 80-100 parts of polyacrylonitrile, and 6-18 parts of synergistic antibacterial agent.

[0007] Adding bamboo fiber as a natural fiber is non-toxic and degradable. There are a large number of hydroxyl groups on its macromolecular chain, which makes a large number of hydrogen bonds between cellulose molecules. Therefore, many organic and inorganic solvents are difficult to dissolve it. By activating it, not only the characteristics of bamboo fiber are retained, but also its processability is improved, and the antibacterial and mechanical properties of the fiber are enhanced.

[0008] Furthermore, the synergistic antibacterial agent is prepared by the following steps: S1. Place a three-necked round-bottom flask equipped with a thermometer stirrer and a reflux condenser in a water bath, mix and stir 4-bromo-1-butene and acetonitrile, and add 5-chloro-2-methylisothiazoline-3-one while stirring. After stirring, control the reaction temperature to 85° C., condense and reflux for 8 hours, and after the reaction is completed, remove the solvent acetonitrile by vacuum distillation under reduced pressure, wash and purify with acetone, and vacuum dry at 80° C. to obtain intermediate 1; the ratio of 4-bromo-1-butene, acetonitrile, and 5-chloro-2-methylisothiazoline-3-one is 13.3 g:100 mL:14.8 g; 4-Bromo-1-butene and 5-chloro-2-methylisothiazoline-3-one undergo quaternization reaction to obtain intermediate 1; the specific reaction is shown below: S2. In a three-necked flask equipped with a stirring device, maleic acid, guanidine hydrochloride and anhydrous ethanol were mixed and stirred continuously until the solid was completely dissolved. Nitrogen was introduced into the device as a protective gas, and the device was placed in a water bath. The reaction temperature was controlled to be maintained at 75°C. The reaction was stirred continuously at a constant temperature for 6 hours. After the reaction was completed, the solvent was removed by vacuum distillation, and the mixture was washed with deionized water and dried in vacuo to obtain intermediate 2. The ratio of maleic acid, guanidine hydrochloride and anhydrous ethanol was 9.8g:20.2g:100mL. The carboxyl group in the maleic acid molecule undergoes an amidation reaction with the amino group in the guanidine hydrochloride molecule, and by controlling the molar ratio of the two to be close to 1:2 and a slight excess of guanidine hydrochloride, the two carboxyl groups in the maleic acid participate in the reaction to obtain intermediate 2; the structure of intermediate 2 is shown below: S3. In a three-necked flask equipped with a stirring device, intermediate 2, intermediate 1 and N,N-dimethylformamide (DMF) are mixed and stirred evenly, and then azobisisobutyronitrile (AIBN) is added. The mixture is copolymerized in a constant temperature water bath at 80°C with constant temperature stirring for 8 hours. After the reaction is completed, the solid is precipitated with distilled water and placed in a vacuum drying oven at 80°C and 0.2MPa for 12 hours to obtain a synergistic antibacterial agent. The ratio of intermediate 2, intermediate 1, N,N-dimethylformamide and azobisisobutyronitrile is 16.8g:20.4g:150mL:0.7g. Under the action of azobisisobutyronitrile, the unsaturated carbon-carbon double bonds of intermediate 2 and intermediate 1 molecules undergo polymerization reaction to obtain a synergistic antibacterial agent; the specific reaction is as follows: The synergistic antimicrobial agent has the efficacy of guanidine antimicrobial agents, which can inhibit the growth and division of bacteria, spore germination, and produce abnormal phenomena such as respiratory inhibition, cell swelling, cytoplasmic disintegration and cell wall destruction. Thus, the purpose of inhibiting or killing bacteria is achieved, and the antibacterial property of the polyacrylonitrile matrix can be improved. In addition, the guanidine hydrochloride structure has high hygroscopicity and ionic conductivity, and can absorb moisture in the air to form a conductive ion channel, thereby reducing the resistivity of the matrix and reducing the accumulation of static electricity. In addition, guanidine hydrochloride can also form a conductive film on the surface of the matrix, so that static electricity can be quickly discharged, avoiding the accumulation and discharge of static electricity, and enhancing the antistatic property of the matrix. In addition, the synergistic antibacterial agent molecule also contains isothiazolinone and quaternary ammonium salt ions, wherein the active site on the heterocyclic ring of isothiazolinone forms a disulfide bond with the sulfhydryl group on the cysteine ​​in the pathogen protein, thereby inactivating the protein to achieve the purpose of sterilization, further enhancing the antibacterial property of the matrix; finally, the introduced quaternary ammonium salt ions will produce a strong electrostatic interaction between the positively charged and negatively charged bacteria, and will have a strong adsorption effect on the bacteria, which can play a synergistic role with isothiazolinone and guanidine hydrochloride, significantly enhancing the antibacterial property of the matrix, and can further enhance the antistatic property of the matrix; It should be further explained that the prepared synergistic antibacterial agent is a polymer macromolecule, which is less likely to migrate and seep out than small molecule antibacterial agents and has more stable performance.

[0009] Beneficial effects of the present invention: 1. The polyacrylonitrile fiber prepared by the present invention is added with bamboo fiber and activated, which not only improves its processability but also enhances the antibacterial and mechanical properties of the fiber; 2. In the prepared synergistic antibacterial agent molecules, the various groups can play a synergistic role, significantly enhancing the antibacterial and antistatic properties of the fiber, and the performance is stable and washable; Therefore, the polyacrylonitrile fiber prepared by the present invention has excellent mechanical properties, stable and efficient antibacterial and antistatic properties, and has important application value in the field of antibacterial fiber technology. DETAILED DESCRIPTION

[0010] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments 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.

[0011] Embodiment 1 Preparation of synergistic antimicrobial agents: S1. Place a three-necked round-bottom flask equipped with a thermometer stirrer and a reflux condenser in a water bath, mix and stir 13.3 g of 4-bromo-1-butene and 100 mL of acetonitrile, and add 14.8 g of 5-chloro-2-methylisothiazoline-3-one while stirring. After stirring, control the reaction temperature to 85° C., condense and reflux for 8 hours, and after the reaction is completed, remove the solvent acetonitrile by distillation under reduced pressure, wash and purify with acetone, and vacuum dry at 80° C. to obtain intermediate 1; S2. In a three-necked flask equipped with a stirring device, 9.8 g of maleic acid, 20.2 g of guanidine hydrochloride and 100 mL of anhydrous ethanol were mixed and stirred continuously until the solid was completely dissolved. Nitrogen was introduced into the device as a protective gas, and then the device was placed in a water bath. The reaction temperature was controlled to be maintained at 75°C. The reaction was stirred continuously at a constant temperature for 6 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure, the product was washed with deionized water, and vacuum dried to obtain intermediate 2. S3. In a three-necked flask equipped with a stirring device, 16.8 g of intermediate 2, 20.4 g of intermediate 1 and 150 mL of N,N-dimethylformamide were mixed and stirred evenly. Then, 0.7 g of azobisisobutyronitrile was added and copolymerized in a constant temperature water bath at 80°C with constant temperature stirring for 8 hours. After the reaction was completed, the solid was precipitated with distilled water and dried in a vacuum drying oven at 80°C and 0.2 MPa for 12 hours to obtain a synergistic antibacterial agent.

[0012] Embodiment 2 Preparation of synergistic antimicrobial agents: S1. Place a three-necked round-bottom flask equipped with a thermometer stirrer and a reflux condenser in a water bath, mix and stir 26.6 g of 4-bromo-1-butene and 200 mL of acetonitrile, and add 29.6 g of 5-chloro-2-methylisothiazoline-3-one while stirring. After stirring, control the reaction temperature to 85° C., condense and reflux for 8 hours, and after the reaction is completed, remove the solvent acetonitrile by distillation under reduced pressure, wash and purify with acetone, and vacuum dry at 80° C. to obtain intermediate 1; S2. In a three-necked flask equipped with a stirring device, 19.6 g of maleic acid, 40.4 g of guanidine hydrochloride and 200 mL of anhydrous ethanol were mixed and stirred continuously until the solid was completely dissolved. Nitrogen was introduced into the device as a protective gas, and then the device was placed in a water bath. The reaction temperature was controlled to be maintained at 75°C. The reaction was stirred continuously at a constant temperature for 6 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure, the product was washed with deionized water, and vacuum dried to obtain intermediate 2. S3. In a three-necked flask equipped with a stirring device, 33.6 g of intermediate 2, 40.8 g of intermediate 1 and 300 mL of N,N-dimethylformamide were mixed and stirred evenly. Then, 1.4 g of azobisisobutyronitrile was added and copolymerized in a constant temperature water bath at 80°C with constant temperature stirring for 8 hours. After the reaction was completed, the solid was precipitated with distilled water and dried in a vacuum drying oven at 80°C and 0.2 MPa for 12 hours to obtain a synergistic antibacterial agent.

[0013] Embodiment 3 A1. Heat 50 mL of N,N-dimethylacetamide to 110°C, condense and reflux under nitrogen protection, add 18 g of bamboo fiber for activation for 1 hour, cool the reaction system to 80°C, add 10 g of LiCl powder and stir to dissolve for 1 hour, stop heating, and continue stirring until the reaction system cools to room temperature. Finally, remove the foam by ultrasonication to obtain an activated bamboo fiber spinning solution. A2. Mix 80 g of polyacrylonitrile with 200 mL of N,N-dimethylacetamide and stir continuously until the polyacrylonitrile is completely dissolved, add the activated bamboo fiber spinning solution prepared in step A1 and 6 g of the synergistic antibacterial agent prepared in Example 1 and mix by ultrasonic oscillation, then adopt an electrospinning process (temperature of 50° C., spinning voltage of 20 kV, injection speed of electrospinning of 10 mm / s, and speed of the receiver of 35 r / min) to obtain primary fibers, and then stretch, heat-set (heat-setting temperature of 70° C., time of 12 h), and wind and collect to obtain antibacterial polyacrylonitrile fibers.

[0014] Embodiment 4 A1. N,N-dimethylacetamide was heated to 135°C, condensed and refluxed under nitrogen protection, 21g of bamboo fiber was added for activation for 1.5h, the reaction system was cooled to 90°C, 12.5g of LiCl powder was added and stirred for dissolution for 2h, heating was stopped, and stirring was continued until the reaction system cooled to room temperature, and finally, ultrasonic defoaming was performed to obtain an activated bamboo fiber spinning solution; A2. Mix 90 g of polyacrylonitrile and N,N-dimethylacetamide, and stir continuously until the polyacrylonitrile is completely dissolved. Add the activated bamboo fiber spinning solution prepared in step A1 and 12 g of the synergistic antibacterial agent prepared in Example 2, and mix by ultrasonic oscillation. Then, adopt an electrospinning process (temperature of 50° C., spinning voltage of 20 kV, injection speed of electrospinning of 10 mm / s, and speed of the receiver of 35 r / min) to obtain primary fibers, and then stretch, heat-set (heat-setting temperature of 70° C., time of 12 h), and wind and collect to obtain antibacterial polyacrylonitrile fibers.

[0015] Embodiment 5 A1. N,N-dimethylacetamide was heated to 150°C, condensed and refluxed under nitrogen protection, 24g of bamboo fiber was added for activation for 2h, the reaction system was cooled to 100°C, 15g of LiCl powder was added and stirred for dissolution for 3h, heating was stopped, and stirring was continued until the reaction system cooled to room temperature, and finally, ultrasonic defoaming was performed to obtain an activated bamboo fiber spinning solution; A2. Mix 100 g of polyacrylonitrile and N,N-dimethylacetamide, and stir continuously until the polyacrylonitrile is completely dissolved. Add the activated bamboo fiber spinning solution prepared in step A1 and 18 g of the synergistic antibacterial agent prepared in Example 2 and mix them by ultrasonic oscillation. Then, adopt an electrospinning process (temperature of 50° C., spinning voltage of 20 kV, injection speed of electrospinning of 10 mm / s, and speed of the receiver of 35 r / min) to obtain primary fibers, and then stretch, heat-set (heat-setting temperature of 70° C., time of 12 h), and wind and collect to obtain antibacterial polyacrylonitrile fibers.

[0016] Comparative Example 1 The synergistic antibacterial agent in Example 5 was replaced by a commercially available quaternary ammonium salt antibacterial agent, and the remaining steps were the same as those in Example 5 to prepare polyacrylonitrile fiber.

[0017] Comparative Example 2 Commercially available polyacrylonitrile fibers were used.

[0018] Embodiments 3, 4, 5, and comparative examples 1 and 2 were woven into fabrics and the following performance tests were performed: The elongation at break was determined using the national standard GB / T 3923.1-2013 “Tensile properties of textile fabrics Part 1: Determination of breaking strength and elongation at break (strip method)”; The national standard GB / T 20944.2-2007 "Evaluation of antimicrobial properties of textiles - Part 2: Absorption method" was used to determine the antibacterial rates of Escherichia coli and Staphylococcus aureus before and after washing the samples 30 times; The national standard GB / T 12703.2-2009 "Textile electrostatic test method Part 2: Charge surface density" is used to measure the charge surface density of the fabric (uC / m 2 ), so as to test the antistatic performance (the smaller the charge surface density, the better the antistatic performance); The measured results are shown in the following table: It can be seen from the above table that the polyacrylonitrile fiber prepared in the embodiment of the present invention has good mechanical properties, and its antibacterial and antistatic properties are higher than those of the control example. Moreover, the performance remains stable after washing 30 times, and it has important application value in the field of antibacterial fiber technology.

[0019] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0020] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing antibacterial polyacrylonitrile fiber, characterized in that: The following steps are involved: A1. N,N-dimethylacetamide is heated to 110-150°C, condensed and refluxed under nitrogen protection, and bamboo fiber is added for activation for 1-2 hours. The reaction system is cooled to 80-100°C, LiCl powder is added and stirred to dissolve for 1-3 hours, and then heating is stopped and stirring is continued until the temperature drops to room temperature. Finally, ultrasonic defoaming is performed to obtain an activated bamboo fiber spinning solution. A2. Mix polyacrylonitrile and N,N-dimethylacetamide, and stir continuously until the polyacrylonitrile is completely dissolved, add the activated bamboo fiber spinning solution prepared in step A1 and the synergistic antibacterial agent, mix by ultrasonic oscillation, and then use an electrospinning process to obtain primary fibers, and then obtain antibacterial polyacrylonitrile fibers through drawing, heat setting, winding and collection.

2. The method for preparing an antibacterial polyacrylonitrile fiber according to claim 1, characterized in that: The synergistic antibacterial agent is prepared by the following steps: S1, 4-bromo-1-butene and acetonitrile were mixed and stirred, and 5-chloro-2-methylisothiazoline-3-one was added while stirring. After stirring, the mixture was condensed and refluxed at 85° C. for 8 h. After the reaction was completed, the mixture was distilled under reduced pressure, washed and purified, and vacuum dried to obtain intermediate 1; S2, maleic acid, guanidine hydrochloride and anhydrous ethanol were mixed, and stirring was continued until the solid was completely dissolved, nitrogen was introduced, and the device was placed in a water bath, and stirred at 75°C for 6 hours. After the reaction was completed, vacuum distillation was performed, washing, and vacuum drying were performed to obtain intermediate 2; S3. Mix intermediate 2, intermediate 1 and N,N-dimethylformamide, stir evenly, add azobisisobutyronitrile, and stir at 80°C for copolymerization. The reaction is completed for 8 hours. After precipitation with distilled water, the obtained solid is vacuum dried to obtain a synergistic antibacterial agent.

3. The method for preparing an antibacterial polyacrylonitrile fiber according to claim 2, characterized in that: In step S1, the ratio of 4-bromo-1-butene, acetonitrile and 5-chloro-2-methylisothiazoline-3-one is 13.3 g:100 mL:14.8 g.

4. The method for preparing an antibacterial polyacrylonitrile fiber according to claim 2, characterized in that: In step S2, the ratio of maleic acid, guanidine hydrochloride and anhydrous ethanol is 9.8 g:20.2 g:100 mL.

5. The method for preparing antibacterial polyacrylonitrile fiber according to claim 2, characterized in that: In step S3, the ratio of the amount of intermediate 2, intermediate 1, N,N-dimethylformamide and azobisisobutyronitrile is 16.8 g:20.4 g:150 mL:0.7 g.

6. The method for preparing antibacterial polyacrylonitrile fiber according to claim 1, characterized in that: The raw materials are calculated in parts by weight as follows: 18-24 parts of bamboo fiber, 10-15 parts of LiCl powder, 80-100 parts of polyacrylonitrile, and 6-18 parts of synergistic antibacterial agent.

7. An antibacterial polyacrylonitrile fiber, characterized in that: Prepared according to the method according to any one of claims 1 to 6.

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