Antibacterial chitosan-modified polypropylene fiber and method for preparing the same

Abstract

The application relates to the technical field of new materials, and discloses an antibacterial chitosan modified polypropylene fiber, and isothiazolinone is used as a heterocyclic compound, the antibacterial mechanism of which is mainly non-oxygenated antibacterial, hydrogen bonds are formed between the heterocyclic compound and the bases of DNA in the bacteria, so that the structure of the DNA is destroyed, the effect of antibacterial inhibition is achieved, cationic quaternary ammonium salt antibacterial groups are introduced into the chitosan molecular chain, the cell membrane and the cell wall of the bacteria can be destroyed through the electric field attraction, so that the antibacterial effect is achieved, under the synergistic effect of the two antibacterial functional groups, the effect of bactericidal inhibition can be achieved on most bacteria on the surface of the fabric, meanwhile, because the chitosan is introduced, the remaining hydrophilic groups such as hydroxyl groups and amino groups on the chitosan can improve the dyeing performance of the polypropylene, play the role of a dyeing finishing agent, and make the fabric made of the antibacterial polypropylene fiber have more long-acting and persistent antibacterial performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new materials, in particular to an antibacterial chitosan modified polypropylene fiber and a preparation method thereof. BACKGROUND

[0002] With the continuous development of society, synthetic fibers are also more and more widely used in daily life. Polypropylene fiber, also known as polypropylene fiber, has the advantages of good fiber luster, soft hand feeling, good drapability, small density, easy processing, etc. Therefore, it has a very wide application in the textile industry. With the continuous development of antibacterial materials, the way of making antibacterial fabric through antibacterial fiber has become an effective way to improve product added value. However, due to the poor hydrophilicity of polypropylene, it is difficult to dye and modify antibacterial by dipping, so other ways are needed to modify the fiber itself.

[0003] In Chinese patent CN103059405B "antibacterial polypropylene plastic", a kind of antibacterial polypropylene plastic is disclosed, which is modified by adding a composite antibacterial agent made of nanometer titanium dioxide, nanometer zeolite, polyhexamethylene guanidine phosphate and other antibacterial materials to polypropylene. However, through simple blending modification, the long-term antibacterial effect of the fiber is not significantly improved. Especially, the fabric often needs to be washed, so it is necessary to introduce antibacterial groups by grafting. By introducing the commonly used isothiazolinone antibacterial finishing agent into the chitosan macromolecule through grafting, and quaternizing the chitosan, the polypropylene has excellent long-term antibacterial performance. The introduction of chitosan can also enhance the dyeability of polypropylene.

[0004] (I) Technical problems to be solved

[0005] In view of the shortcomings of the prior art, the present application provides an antibacterial chitosan modified polypropylene fiber and a preparation method thereof, which solves the problem of short antibacterial effect and general antibacterial effect of simple blending of antibacterial agent.

[0006] (II) Technical scheme

[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a preparation method of an antibacterial chitosan modified polypropylene fiber comprises the following steps:

[0008] (1) N-carboxymethyl chitosan and thionyl chloride are added to a reaction container, then an acid binding agent pyridine is added, heated to 50-70℃, and reacted for 16-32h. After the reaction is completed, rotary evaporation is carried out to obtain acyl chloride chitosan;

[0009] (2) The acyl chloride chitosan is added to a mixed solvent, then benzylpropyl isothiazol-3-one and pyridine are added, and stirred at 30-50℃ for 2-4h. After the reaction is completed, isothiazolinone grafted chitosan is obtained.

[0010] (3) adding the isothiazolinone grafted chitosan into the mixed solvent, then adding the glycidyl dimethyl hexyl ammonium chloride with the molecular formula of C 11 H 24 ClNO, adding NaOH to adjust the pH to 9-10, heating to 70-90℃, stirring for 8-16h, after the reaction is completed, dialysis, freeze-drying, to obtain the antibacterial modified chitosan;

[0011] (4) adding the polypropylene, maleic anhydride grafted polypropylene, antioxidant 168 into the torque rheometer, adding the antibacterial modified chitosan at 100-120℃, then mixing at 200-240℃ for 10-30min, then melt spinning, to obtain the antibacterial chitosan modified polypropylene fiber.

[0012] Preferably, the mixed solvent in the step (2) is the mixed solvent of N,N-dimethylacetamide and dichloromethane with a mass ratio of 100:80-150.

[0013] Preferably, the mass ratio of the acyl chloride chitosan, phenylpropyl isothiazol-3-one and pyridine in the step (2) is 100:18-40:15-30.

[0014] Preferably, the mixed solvent in the step (3) is the mixed solvent of N,N-dimethylacetamide and deionized water with a mass ratio of 100:150-250.

[0015] Preferably, the mass ratio of the isothiazolinone grafted chitosan and the glycidyl dimethyl hexyl ammonium chloride in the step (3) is 100:15-30.

[0016] Preferably, the mass ratio of the polypropylene, maleic anhydride grafted polypropylene, antioxidant 168 and the antibacterial modified chitosan in the step (4) is 100:2-5:0.8-2:0.5-3.

[0017] (Three) beneficial technical effects

[0018] Compared with the prior art, the present application has the following experimental principles and beneficial technical effects:

[0019] The antibacterial chitosan modified polypropylene fiber is prepared by the following steps: first, acyl chlorination is carried out on low-N-carboxymethyl chitosan by using thionyl chloride, so as to obtain acyl chlorination chitosan; under the condition of pyridine acid binding agent, amidation reaction occurs between the acyl chloro carbonyl carbon and the nitrogen on the benzisothiazole-3-ketone, so that the isothiazolinone group is grafted on the chitosan; then, ring-opening grafting occurs between the hydroxymethyl on the isothiazolinone grafted chitosan and the glycidyl dimethyl hexyl ammonium chloride epoxy group, so that the quaternary ammonium salt is grafted on the surface of the chitosan, thereby obtaining the double-functional antibacterial modified chitosan containing the quaternary ammonium salt functional group and the isothiazolinone functional group; and then, the antibacterial modified chitosan, polypropylene, a compatibilizer maleic anhydride grafted polypropylene and an antioxidant are melt-blended and melt-spun, so as to obtain the antibacterial chitosan modified polypropylene fiber. The isothiazolinone is a heterocyclic compound, and the antibacterial mechanism thereof is mainly non-oxidative antibacterial. The heterocyclic ring forms a hydrogen bond with the base of DNA in the bacteria, so as to destroy the DNA structure, so that the bacteria lose the ability of replication, thereby achieving the effect of antibacterial and bacteriostatic. The cationic quaternary ammonium salt antibacterial group is introduced on the molecular chain of the chitosan, and can destroy the cell membrane and cell wall of the bacteria through the electric field attraction, thereby achieving the antibacterial effect. Under the synergistic effect of the two antibacterial functional groups, the most bacteria on the surface of the fabric can be killed and inhibited, thereby giving the fabric made of the polypropylene fiber excellent antibacterial performance.

[0020] The antibacterial chitosan modified polypropylene fiber has the following advantages: the introduction of the chitosan can improve the dyeing performance of the polypropylene and play the role of the dyeing finishing agent; the active groups on the chitosan can react with the anhydride groups on the compatibilizer, so that the chitosan has relatively good dispersibility, and the small antibacterial groups grafted on the chitosan do not separate or elute, so that the fabric made of the antibacterial polypropylene fiber has long-lasting antibacterial performance. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The reaction diagram for preparing the acyl chlorination chitosan;

[0022] Figure 2 The reaction diagram for preparing the isothiazolinone grafted chitosan;

[0023] Figure 3 The reaction diagram for preparing the antibacterial modified chitosan. DETAILED DESCRIPTION

[0024] A preparation method of an antibacterial chitosan modified polypropylene fiber, characterized in that the method comprises the following steps:

[0025] (1) 0.4-1.2 g of N-carboxymethyl chitosan and 30-60 g of thionyl chloride are added into a reaction vessel, then 0.8-1.6 g of acid-binding agent pyridine is added, heated to 50-70 °C, and reacted for 16-32 h. After the reaction is completed, rotary evaporation is performed to obtain acyl chloride chitosan;

[0026] (2) 0.5 g of acyl chloride chitosan is added into 50 g of a mixed solvent of N,N-dimethylacetamide and 40-70 g of dichloromethane, then 0.09-0.2 g of phenylpropylisothiazol-3-one and 0.08-0.15 g of pyridine are added, and stirred at 30-50 °C for 2-4 h. After the reaction is completed, isothiazolone grafted chitosan is obtained;

[0027] (3) 0.4 g of isothiazolone grafted chitosan is added into 20 g of a mixed solvent of N,N-dimethylacetamide and 30-50 g of deionized water, then 0.06-0.12 g of glycidyl dimethyl hexyl ammonium chloride with the molecular formula of C 11 H 24 ClNO is added, NaOH is added to adjust the pH to 9-10, the temperature is raised to 70-90 °C, and stirred for 8-16 h. After the reaction is completed, dialysis and freeze-drying are performed to obtain antibacterial modified chitosan;

[0028] (4) 300 g of polypropylene, 6-15 g of maleic anhydride grafted polypropylene, and 2.4-6 g of antioxidant 168 are added into a torque rheometer, 1.5-9 g of antibacterial modified chitosan is added at 100-120 °C, then mixed at 200-240 °C for 10-30 min, and then melt spinning is performed to obtain antibacterial chitosan modified polypropylene fibers.

[0029] Example 1

[0030] (1) 0.4 g of N-carboxymethyl chitosan and 30 g of thionyl chloride are added into a reaction vessel, then 0.8 g of acid-binding agent pyridine is added, heated to 50 °C, and reacted for 16 h. After the reaction is completed, rotary evaporation is performed to obtain acyl chloride chitosan;

[0031] (2) 0.5 g of acyl chloride chitosan is added into 50 g of a mixed solvent of N,N-dimethylacetamide and 40 g of dichloromethane, then 0.09 g of phenylpropylisothiazol-3-one and 0.08 g of pyridine are added, and stirred at 30 °C for 2 h. After the reaction is completed, isothiazolone grafted chitosan is obtained;

[0032] (3) 0.4 g of isothiazolone grafted chitosan is added into 20 g of a mixed solvent of N,N-dimethylacetamide and 30 g of deionized water, then 0.06 g of glycidyl dimethyl hexyl ammonium chloride with the molecular formula of C 11 H 24glycidyl dimethyl hexyl ammonium chloride of ClNO, NaOH is added to adjust pH to 9, temperature is raised to 70℃, stirring reaction is carried out for 8h, after reaction is completed, dialysis, freeze drying, anti-bacterial modified chitosan is obtained;

[0033] (4) 300g of polypropylene, 6g of maleic anhydride grafted polypropylene, 2.4g of antioxidant 168 are added into a torque rheometer, 1.5g of the anti-bacterial modified chitosan is added at 100℃, then melt spinning is carried out after mixing at 200℃ for 10min, anti-bacterial chitosan modified polypropylene fiber is obtained.

[0034] Example 2

[0035] (1) 0.6g of N-carboxymethyl chitosan and 35g of thionyl chloride are added into a reaction container, then 1g of acid binding agent pyridine is added, heated to 55℃, reaction is carried out for 18h, after reaction is completed, rotary evaporation is carried out, acyl chloride chitosan is obtained;

[0036] (2) 0.5g of acyl chloride chitosan is added into 50g of N,N-dimethylacetamide and 45g of dichloromethane mixed solvent, then 0.11g of phenylpropyl isothiazol-3-one and 0.1g of pyridine are added, stirring reaction is carried out at 35℃ for 2h, after reaction is completed, isothiazolinone grafted chitosan is obtained;

[0037] (3) 0.4g of isothiazolinone grafted chitosan is added into 20g of N,N-dimethylacetamide and 40g of deionized water mixed solvent, then 0.08g of C 11 H 24 glycidyl dimethyl hexyl ammonium chloride of ClNO, NaOH is added to adjust pH to 9, temperature is raised to 75℃, stirring reaction is carried out for 10h, after reaction is completed, dialysis, freeze drying, anti-bacterial modified chitosan is obtained;

[0038] (4) 300g of polypropylene, 8g of maleic anhydride grafted polypropylene, 3.6g of antioxidant 168 are added into a torque rheometer, 3g of the anti-bacterial modified chitosan is added at 110℃, then melt spinning is carried out after mixing at 210℃ for 15min, anti-bacterial chitosan modified polypropylene fiber is obtained.

[0039] Example 3

[0040] (1) 0.8g of N-carboxymethyl chitosan and 45g of thionyl chloride are added into a reaction container, then 1.2g of acid binding agent pyridine is added, heated to 60℃, reaction is carried out for 24h, after reaction is completed, rotary evaporation is carried out, acyl chloride chitosan is obtained;

[0041] (2) 0.5 g of the acyl chloride chitosan was added into 50 g of a mixed solvent of N, N-dimethylacetamide and 60 g of dichloromethane, then 0.12 g of phenylpropylisothiazol-3-one and 0.11 g of pyridine were added, and the reaction was stirred at 40°C for 3 h. After the reaction was completed, an isothiazolone grafted chitosan was obtained;

[0042] (3) 0.4 g of the isothiazolone grafted chitosan was added into 20 g of a mixed solvent of N, N-dimethylacetamide and 40 g of deionized water, then 0.09 g of glycidyl dimethylhexyl ammonium chloride with the molecular formula of C 11 H 24 ClNO was added, NaOH was added to adjust the pH to 10, the temperature was raised to 80°C, and the reaction was stirred for 12 h. After the reaction was completed, dialysis and freeze-drying were performed to obtain an antibacterial modified chitosan;

[0043] (4) 300 g of polypropylene, 9 g of maleic anhydride grafted polypropylene, and 4.2 g of antioxidant 168 were added into a torque rheometer, 6 g of the antibacterial modified chitosan was added at 110°C, then the mixture was mixed at 220°C for 20 min, and then melt spinning was performed to obtain an antibacterial chitosan modified polypropylene fiber.

[0044] Example 4

[0045] (1) 1 g of N-carboxymethyl chitosan and 50 g of thionyl chloride were added into a reaction container, then 1.4 g of an acid-binding agent pyridine was added, and the temperature was raised to 60°C. The reaction was performed for 28 h. After the reaction was completed, rotary evaporation was performed to obtain an acyl chloride chitosan;

[0046] (2) 0.5 g of the acyl chloride chitosan was added into 50 g of a mixed solvent of N, N-dimethylacetamide and 60 g of dichloromethane, then 0.15 g of phenylpropylisothiazol-3-one and 0.12 g of pyridine were added, and the reaction was stirred at 45°C for 3 h. After the reaction was completed, an isothiazolone grafted chitosan was obtained;

[0047] (3) 0.4 g of the isothiazolone grafted chitosan was added into 20 g of a mixed solvent of N, N-dimethylacetamide and 45 g of deionized water, then 0.1 g of glycidyl dimethylhexyl ammonium chloride with the molecular formula of C 11 H 24 ClNO was added, NaOH was added to adjust the pH to 10, the temperature was raised to 85°C, and the reaction was stirred for 14 h. After the reaction was completed, dialysis and freeze-drying were performed to obtain an antibacterial modified chitosan;

[0048] (4) 300 g of polypropylene, 12 g of maleic anhydride grafted polypropylene, 5 g of antioxidant 168 were added into a torque rheometer, 8 g of the antibacterial modified chitosan was added at 120°C, followed by mixing at 230°C for 20 min, and then melt spinning to obtain antibacterial chitosan modified polypropylene fibers.

[0049] Example 5

[0050] (1) 1.2 g of N-carboxymethyl chitosan and 60 g of thionyl chloride were added into a reaction container, followed by adding 1.6 g of an acid-binding agent pyridine, heated to 70°C, and reacted for 32 h. After the reaction was completed, rotary evaporation was performed to obtain acyl chloride chitosan;

[0051] (2) 0.5 g of acyl chloride chitosan was added into 50 g of a mixed solvent of N,N-dimethylacetamide and 70 g of dichloromethane, followed by adding 0.2 g of phenylpropylisothiazol-3-one and 0.15 g of pyridine, and stirring at 50°C for 4 h. After the reaction was completed, isothiazolinone grafted chitosan was obtained;

[0052] (3) 0.4 g of isothiazolinone grafted chitosan was added into 20 g of a mixed solvent of N,N-dimethylacetamide and 50 g of deionized water, followed by adding 0.12 g of glycidyl dimethylhexyl ammonium chloride with a molecular formula of C 11 H 24 ClNO, NaOH was added to adjust the pH to 10, the temperature was raised to 90°C, and stirring was performed for 16 h. After the reaction was completed, dialysis and freeze-drying were performed to obtain antibacterial modified chitosan;

[0053] (4) 300 g of polypropylene, 15 g of maleic anhydride grafted polypropylene, and 6 g of antioxidant 168 were added into a torque rheometer, 9 g of the antibacterial modified chitosan was added at 120°C, followed by mixing at 240°C for 30 min, and then melt spinning to obtain antibacterial chitosan modified polypropylene fibers.

[0054] Comparative Example 1

[0055] (1) 0.4 g of chitosan was added into 20 g of a mixed solvent of N,N-dimethylacetamide and 50 g of deionized water, followed by adding 0.01 g of glycidyl dimethylhexyl ammonium chloride with a molecular formula of C 11 H 24 ClNO, NaOH was added to adjust the pH to 9, the temperature was raised to 80°C, and stirring was performed for 12 h. After the reaction was completed, dialysis and freeze-drying were performed to obtain quaternary ammonium salt modified chitosan;

[0056] (2) 300 g of polypropylene, 10 g of maleic anhydride grafted polypropylene, 3.6 g of antioxidant 168 were added into a torque rheometer, 6 g of quaternary ammonium salt modified chitosan was added at 110°C, then mixed at 220°C for 15 min, and then melt spinning was performed, to obtain quaternary ammonium salt chitosan modified polypropylene fibers.

[0057] The polypropylene fibers prepared in Examples 1-5 and Comparative Example 1 were compared, as follows:

[0058] The polypropylene fibers prepared in the Examples and Comparative Example were respectively spun into 4.0 cm x 4.0 cm samples, 0.2 ml of a staphylococcus aureus bacterial suspension was dropped onto the surface of the samples, and incubated at 35°C in an environment with a humidity of 90% for 24 h, the bacterial solution was washed off with 10 ml of SCDLP culture solution, diluted 10 times with physiological saline, 1 ml of the diluted solution was spread on a plate count agar, and incubated at 35°C for 48 h, the count was observed, and the antibacterial rate was calculated.

[0059]

Claims

1. An antibacterial chitosan-modified polypropylene fiber, characterized by: The preparation method of the antibacterial chitosan modified polypropylene fiber comprises the following steps: (1) adding N-carboxymethyl chitosan and chlorosulfoxide into a reaction container, then adding an acid-binding agent pyridine, heating to 50-70 DEG C, and reacting for 16-32 h; after the reaction is completed, rotary evaporation is performed to obtain acyl chloride chitosan; (2) adding the acyl chloride chitosan into a mixed solvent, then adding benzylpropylisothiazol-3-ketone and pyridine, and stirring and reacting at 30-50 DEG C for 2-4 h; after the reaction is completed, isothiazolinone grafted chitosan is obtained; (3) adding isothiazolinone grafted chitosan into the mixed solvent, then adding glycidyl dimethyl hexyl ammonium chloride with molecular formula of C 11 H 24 ClNO, adjusting pH to 9-10 by adding NaOH, increasing temperature to 70-90℃, stirring for 8-16h, after the reaction is completed, dialyzing, freeze-drying, to obtain the antibacterial modified chitosan; (4) adding polypropylene, maleic anhydride grafted polypropylene, and antioxidant 168 into a torque rheometer, adding the antibacterial modified chitosan at 100-120 DEG C, then mixing at 200-240 DEG C for 10-30 min, and then performing melt spinning to obtain the antibacterial chitosan modified polypropylene fiber; The reaction diagram for preparing the antibacterial modified chitosan is as follows: 。 2. The antibacterial chitosan-modified polypropylene fiber according to claim 1, characterized by: In the step (2), the mixed solvent is a mixed solvent of N,N-dimethylacetamide and dichloromethane with a mass ratio of 100:80-150.

3. The antibacterial chitosan-modified polypropylene fiber according to claim 1, characterized by: In the step (2), the mass ratio of the acyl chloride chitosan, the benzylpropylisothiazol-3-ketone, and the pyridine is 100:18-40:15-30.

4. The antibacterial chitosan-modified polypropylene fiber according to claim 1, characterized by: In the step (3), the mixed solvent is a mixed solvent of N,N-dimethylacetamide and deionized water with a mass ratio of 100:150-250.

5. The antibacterial chitosan-modified polypropylene fiber according to claim 1, characterized by: In the step (3), the mass ratio of the isothiazolinone grafted chitosan and the glycidyl dimethylhexyl ammonium chloride is 100:15-30.

6. The antibacterial chitosan-modified polypropylene fiber according to claim 1, characterized by: In the step (4), the mass ratio of the polypropylene, the maleic anhydride grafted polypropylene, the antioxidant 168, and the antibacterial modified chitosan is 100:2-5:0.8-2:0.5-3.

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