Antibacterial chitosan modified polypropylene fiber and preparation method thereof

Abstract

The invention relates to the technical field of new materials, and discloses an antibacterial chitosan modified polypropylene fiber, isothiazolinone is used as a heterocyclic compound, the antibacterial mechanism of the antibacterial chitosan modified polypropylene fiber is mainly non-oxidized antibacterial, and a hydrogen bond is formed by a heterocyclic ring and a basic group of DNA in bacteria, so that the DNA structure is destroyed, and the antibacterial and bacteriostatic effects are achieved; a cationic quaternary ammonium salt antibacterial group is introduced to a chitosan molecular chain, cell membranes and cell walls of bacteria can be destroyed through the gravitation effect of an electric field, so that the antibacterial effect is achieved, and under the synergistic effect of the two antibacterial functional groups, the sterilization and bacteriostasis effects on most bacteria on the surface of the fabric can be achieved; meanwhile, due to the introduction of chitosan, hydrophilic groups such as residual hydroxyl groups and amino groups on the chitosan can improve the dyeing performance of the polypropylene and play a role in assisting dyeing of a finishing agent, and a fabric made of the antibacterial polypropylene fiber can have a more long-acting and lasting antibacterial performance.

Description

Technical Field

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

[0002] With the continuous development of society, synthetic fibers are used more and more widely in daily life. Polypropylene fiber, also known as polypropylene, has the advantages of good fiber gloss, soft feel, good drape, low density, and easy processing. Therefore, it is widely used in the textile industry. With the continuous development of antibacterial materials, the method of making antibacterial fabrics through antibacterial fibers has also become an effective way to increase the added value of products. However, due to the poor hydrophilicity of polypropylene, it is not only difficult to dye, but also difficult to perform antibacterial modification by dip-dyeing. Therefore, other methods are needed to modify the fiber itself to be antibacterial.

[0003] In Chinese patent CN103059405B "Antibacterial polypropylene plastic", an antibacterial polypropylene plastic is disclosed, which is antibacterial modified by directly adding a composite antibacterial agent made of antibacterial materials such as nano titanium dioxide, nano zeolite, polyhexamethylene guanidine phosphate, etc. to polypropylene. However, the long-term antibacterial effect of the fiber is not significantly improved by simple blending modification, especially since the fabric needs to be washed frequently. Therefore, it is necessary to introduce antibacterial groups by grafting and the like. By introducing the commonly used isothiazolinone antibacterial finishing agent for fabrics into chitosan macromolecules by grafting and quaternizing the chitosan, polypropylene can have excellent long-term antibacterial properties. At the same time, the introduction of chitosan can also enhance the printability and dyeability of polypropylene.

[0004] 1. Technical issues to be resolved In view of the shortcomings of the prior art, the present invention provides an antibacterial chitosan modified polypropylene fiber and a preparation method thereof, which solves the problem that the antibacterial effect of simply blending and adding antibacterial agents is not long-lasting and the antibacterial effect is general.

[0005] (II) Technical solution To achieve the above object, the present invention provides the following technical solution: A method for preparing antibacterial chitosan modified polypropylene fiber comprises the following steps: (1) Add N-carboxymethyl chitosan and thionyl chloride into a reaction vessel, then add acid-binding agent pyridine, heat to 50-70°C, react for 16-32 hours, and after the reaction is completed, rotary evaporate to obtain acyl chloride chitosan; (2) adding chlorinated chitosan to a mixed solvent, followed by adding phenylisothiazol-3-one and pyridine, stirring and reacting at 30-50° C. for 2-4 hours, and after the reaction is completed, isothiazolinone-grafted chitosan is obtained; (3) Add isothiazolinone grafted chitosan to the mixed solvent, and then add11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO, add NaOH to adjust the pH to 9-10, raise the temperature to 70-90°C, stir and react for 8-16h, after the reaction is completed, dialyze and freeze-dry to obtain antibacterial modified chitosan; (4) Add polypropylene, maleic anhydride grafted polypropylene and antioxidant 168 into a torque rheometer, add antibacterial modified chitosan at 100-120°C, then mix at 200-240°C for 10-30 minutes, and then perform melt spinning to obtain antibacterial chitosan modified polypropylene fibers.

[0006] Preferably, the mixed solvent in step (2) is a mixed solvent of N,N-dimethylacetamide and dichloromethane in a mass ratio of 100:80-150.

[0007] Preferably, in step (2), the mass ratio of chitosan chloride, phenylisothiazol-3-one and pyridine is 100:18-40:15-30.

[0008] Preferably, the mixed solvent in step (3) is a mixed solvent of N,N-dimethylacetamide and deionized water in a mass ratio of 100:150-250.

[0009] Preferably, in step (3), the mass ratio of isothiazolinone grafted chitosan to glycidyl dimethylhexyl ammonium chloride is 100:15-30.

[0010] Preferably, in step (4), the mass ratio of polypropylene, maleic anhydride grafted polypropylene, antioxidant 168 and antibacterial modified chitosan is 100:2-5:0.8-2:0.5-3.

[0011] 3. Beneficial technical effects Compared with the prior art, the present invention has the following experimental principles and beneficial technical effects: The antibacterial chitosan modified polypropylene fiber comprises the following steps: firstly, chlorination of low-N-carboxymethyl chitosan with thionyl chloride is performed to obtain chlorinated chitosan; then, under the condition of a pyridine acid binding agent, amidation reaction is performed between the carbonyl carbon of chlorinated chitosan and the nitrogen of benzisothiazol-3-one, so that the isothiazolinone group is grafted onto the chitosan; then, ring-opening grafting is performed between the hydroxymethyl group on the isothiazolinone grafted chitosan and the epoxy group of glycidyl dimethylhexyl ammonium chloride to graft the quaternary ammonium salt onto the surface of the chitosan, so that a bifunctional antibacterial modified chitosan containing a quaternary ammonium salt functional group and an isothiazolinone functional group is obtained; and then, the antibacterial modified chitosan is combined with polypropylene, a compatibilizer maleic anhydride grafted polypropylene and an antioxidant. The agents were melt blended and melt spun to obtain antibacterial chitosan modified polypropylene fiber. As a heterocyclic compound, isothiazolinone has a mainly non-oxidative antibacterial mechanism. It forms hydrogen bonds with the bases of DNA in bacteria through the heterocyclic ring, thereby destroying the DNA structure, causing it to lose its replication ability and achieving antibacterial and bacteriostatic effects. Cationic quaternary ammonium salt antibacterial groups are introduced into the chitosan molecular chain, which can destroy the cell membrane and cell wall of bacteria through the electric field attraction, thereby achieving an antibacterial effect. Under the synergistic effect of the two antibacterial functional groups, most of the bacteria on the surface of the fabric can be sterilized and inhibited, thereby giving the fabric made of polypropylene fiber excellent antibacterial properties.

[0012] The antibacterial chitosan-modified polypropylene fiber has the advantages that the residual hydroxyl groups, amino groups and other hydrophilic groups on the chitosan can improve the dyeing performance of the polypropylene and play the role of a dyeing and finishing agent because the chitosan is introduced. At the same time, the active groups on the chitosan can also react with the anhydride groups on the compatibilizer, so that the chitosan has relatively good dispersibility and the grafted small molecule antibacterial groups will not separate or elute, so that the fabric made of the antibacterial polypropylene fiber has a more long-lasting antibacterial performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The reaction diagram for preparing chitosan chloride; Figure 2 Reaction diagram for the preparation of isothiazolinone grafted chitosan; Figure 3 Reaction diagram for preparing antibacterial modified chitosan. DETAILED DESCRIPTION

[0014] A method for preparing antibacterial chitosan modified polypropylene fiber, characterized in that it comprises the following steps: (1) Add 0.4-1.2 g of N-carboxymethyl chitosan and 30-60 g of thionyl chloride into a reaction vessel, then add 0.8-1.6 g of pyridine as an acid-binding agent, heat to 50-70°C, react for 16-32 hours, and after the reaction is complete, perform rotary evaporation to obtain chlorinated chitosan; (2) Add 0.5 g of chlorinated chitosan to a mixed solvent of 50 g of N,N-dimethylacetamide and 40-70 g of dichloromethane, then add 0.09-0.2 g of phenylisothiazol-3-one and 0.08-0.15 g of pyridine, and stir at 30-50 ° C for 2-4 h. After the reaction is completed, isothiazolinone grafted chitosan is obtained; (3) Add 0.4 g of isothiazolinone grafted chitosan to a mixed solvent of 20 g of N,N-dimethylacetamide and 30-50 g of deionized water, and then add 0.06-0.12 g of C 11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO, add NaOH to adjust the pH to 9-10, raise the temperature to 70-90°C, stir and react for 8-16h, after the reaction is completed, dialyze and freeze-dry to obtain antibacterial modified chitosan; (4) Add 300 g of polypropylene, 6-15 g of maleic anhydride grafted polypropylene, and 2.4-6 g of antioxidant 168 into a torque rheometer, add 1.5-9 g of antibacterial modified chitosan at 100-120°C, then mix at 200-240°C for 10-30 min, and then melt-spin to obtain antibacterial chitosan modified polypropylene fibers.

[0015] Example 1

[0016] (1) Add 0.4 g of N-carboxymethyl chitosan and 30 g of thionyl chloride into a reaction vessel, then add 0.8 g of acid-binding agent pyridine, heat to 50°C, react for 16 h, and after the reaction is complete, rotary evaporate to obtain chlorinated chitosan; (2) Add 0.5 g of chlorinated chitosan to a mixed solvent of 50 g of N,N-dimethylacetamide and 40 g of dichloromethane, then add 0.09 g of phenylisothiazol-3-one and 0.08 g of pyridine, and stir at 30 °C for 2 h. After the reaction is completed, isothiazolinone-grafted chitosan is obtained; (3) 0.4 g of isothiazolinone grafted chitosan was added to a mixed solvent of 20 g of N,N-dimethylacetamide and 30 g of deionized water, followed by the addition of 0.06 g of C 11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO was added with NaOH to adjust the pH to 9, the temperature was raised to 70°C, and the reaction was stirred for 8 hours. After the reaction was completed, the chitosan was dialyzed and freeze-dried to obtain antibacterial modified chitosan. (4) 300 g of polypropylene, 6 g of maleic anhydride grafted polypropylene, and 2.4 g of antioxidant 168 were added into a torque rheometer, and 1.5 g of antibacterial modified chitosan was added at 100 °C, followed by kneading at 200 °C for 10 min, and then melt spinning was performed to obtain antibacterial chitosan modified polypropylene fibers.

[0017] Example 2

[0018] (1) Add 0.6 g of N-carboxymethyl chitosan and 35 g of thionyl chloride into a reaction vessel, then add 1 g of acid-binding agent pyridine, heat to 55 °C, react for 18 h, and after the reaction is complete, rotary evaporate to obtain acyl chloride chitosan; (2) Add 0.5 g of chlorinated chitosan to a mixed solvent of 50 g of N,N-dimethylacetamide and 45 g of dichloromethane, then add 0.11 g of phenylisothiazol-3-one and 0.1 g of pyridine, and stir at 35 °C for 2 h. After the reaction is completed, isothiazolinone-grafted chitosan is obtained; (3) 0.4 g of isothiazolinone grafted chitosan was added to a mixed solvent of 20 g of N,N-dimethylacetamide and 40 g of deionized water, followed by the addition of 0.08 g of C 11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO was added with NaOH to adjust the pH to 9, the temperature was raised to 75°C, and the reaction was stirred for 10 hours. After the reaction was completed, the chitosan was dialyzed and freeze-dried to obtain antibacterial modified chitosan. (4) 300 g of polypropylene, 8 g of maleic anhydride grafted polypropylene, and 3.6 g of antioxidant 168 were added into a torque rheometer, and 3 g of antibacterial modified chitosan was added at 110°C, followed by kneading at 210°C for 15 min, and then melt spinning was performed to obtain antibacterial chitosan modified polypropylene fibers.

[0019] Example 3

[0020] (1) Add 0.8 g of N-carboxymethyl chitosan and 45 g of thionyl chloride into a reaction vessel, then add 1.2 g of acid-binding agent pyridine, heat to 60°C, react for 24 h, and after the reaction is complete, rotary evaporate to obtain chlorinated chitosan; (2) Add 0.5 g of chlorinated chitosan to a mixed solvent of 50 g of N,N-dimethylacetamide and 60 g of dichloromethane, then add 0.12 g of phenylisothiazol-3-one and 0.11 g of pyridine, and stir at 40 °C for 3 h. After the reaction is completed, isothiazolinone-grafted chitosan is obtained; (3) 0.4 g of isothiazolinone grafted chitosan was added to a mixed solvent of 20 g of N,N-dimethylacetamide and 40 g of deionized water, followed by the addition of 0.09 g of C 11 H24 Glycidyl dimethylhexyl ammonium chloride of ClNO was added with NaOH to adjust the pH to 10, and the temperature was raised to 80°C, and the reaction was stirred for 12 hours. After the reaction was completed, the chitosan was dialyzed and freeze-dried to obtain antibacterial modified chitosan. (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, and 6 g of antibacterial modified chitosan was added at 110°C, followed by kneading at 220°C for 20 min, and then melt spinning was performed to obtain antibacterial chitosan modified polypropylene fibers.

[0021] Example 4

[0022] (1) Add 1 g of N-carboxymethyl chitosan and 50 g of thionyl chloride into a reaction vessel, then add 1.4 g of acid-binding agent pyridine, heat to 60°C, react for 28 hours, and after the reaction is complete, rotary evaporate to obtain acyl chloride chitosan; (2) Add 0.5 g of chlorinated chitosan to a mixed solvent of 50 g of N,N-dimethylacetamide and 60 g of dichloromethane, then add 0.15 g of phenylisothiazol-3-one and 0.12 g of pyridine, and stir at 45 °C for 3 h. After the reaction is completed, isothiazolinone-grafted chitosan is obtained; (3) 0.4 g of isothiazolinone grafted chitosan was added to a mixed solvent of 20 g of N,N-dimethylacetamide and 45 g of deionized water, followed by the addition of 0.1 g of C 11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO was added with NaOH to adjust the pH to 10, and the temperature was raised to 85°C, and the reaction was stirred for 14 hours. After the reaction was completed, the chitosan was dialyzed and freeze-dried to obtain antibacterial modified chitosan. (4) 300 g of polypropylene, 12 g of maleic anhydride grafted polypropylene, and 5 g of antioxidant 168 were added into a torque rheometer, and 8 g of antibacterial modified chitosan was added at 120 °C, followed by kneading at 230 °C for 20 min, and then melt spinning was performed to obtain antibacterial chitosan modified polypropylene fibers.

[0023] Example 5

[0024] (1) Add 1.2 g of N-carboxymethyl chitosan and 60 g of thionyl chloride into a reaction vessel, then add 1.6 g of acid-binding agent pyridine, heat to 70°C, react for 32 hours, and after the reaction is complete, rotary evaporate to obtain acyl chloride chitosan; (2) Add 0.5 g of chlorinated chitosan to a mixed solvent of 50 g of N,N-dimethylacetamide and 70 g of dichloromethane, then add 0.2 g of phenylisothiazol-3-one and 0.15 g of pyridine, and stir at 50 °C for 4 h. After the reaction is completed, isothiazolinone-grafted chitosan is obtained; (3) 0.4 g of isothiazolinone grafted chitosan was added to a mixed solvent of 20 g of N,N-dimethylacetamide and 50 g of deionized water, followed by the addition of 0.12 g of C 11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO was added with NaOH to adjust the pH to 10, and the temperature was raised to 90°C, and the reaction was stirred for 16 hours. After the reaction was completed, the chitosan was dialyzed and freeze-dried to obtain antibacterial modified chitosan. (4) 300 g of polypropylene, 15 g of maleic anhydride grafted polypropylene, and 6 g of antioxidant 168 were added into a torque rheometer, and 9 g of antibacterial modified chitosan was added at 120°C, followed by kneading at 240°C for 30 min, and then melt spinning was performed to obtain antibacterial chitosan modified polypropylene fibers.

[0025] Comparative Example 1 (1) Add 0.4 g chitosan to a mixed solvent of 20 g N,N-dimethylacetamide and 50 g deionized water, and then add 0.01 g C 11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO was added with NaOH to adjust the pH to 9, and the temperature was raised to 80°C, and the reaction was stirred for 12 hours. After the reaction was completed, the chitosan was dialyzed and freeze-dried to obtain quaternary ammonium salt modified chitosan. (2) 300 g of polypropylene, 10 g of maleic anhydride grafted polypropylene, and 3.6 g of antioxidant 168 were added into a torque rheometer, and 6 g of quaternary ammonium salt modified chitosan was added at 110°C, followed by kneading at 220°C for 15 min, and then melt spinning was performed to obtain quaternary ammonium salt chitosan modified polypropylene fibers.

[0026] The polypropylene fibers prepared in Examples 1-5 and Comparative Example 1 are compared as follows: The polypropylene fiber fabrics prepared in the embodiment and the comparative example were respectively cut into 4.0 cm × 4.0 cm samples, 0.2 ml of Staphylococcus aureus suspension was dropped on the surface of the sample, and cultured at 35 ° C and 90% humidity for 24 h, the bacterial solution was washed with 10 ml of SCDLP culture medium, and then diluted 10 times with physiological saline, 1 ml of the dilution was dispersed in plate count agar, and cultured at 35 ° C for 48 h, the count was observed, and the antibacterial rate was calculated.

[0027]

Claims

1. An antibacterial chitosan modified polypropylene fiber, characterized in that: The method for preparing an antibacterial chitosan modified polypropylene fiber comprises the following steps: (1) Add N-carboxymethyl chitosan and thionyl chloride into a reaction vessel, then add acid-binding agent pyridine, heat to 50-70°C, react for 16-32 hours, and after the reaction is completed, rotary evaporate to obtain acyl chloride chitosan; (2) adding chlorinated chitosan to a mixed solvent, followed by adding phenylisothiazol-3-one and pyridine, stirring and reacting at 30-50° C. for 2-4 hours, and after the reaction is completed, isothiazolinone-grafted chitosan is obtained; (3) Add isothiazolinone grafted chitosan to the mixed solvent, and then add 11 H 24 Glycidyl dimethylhexyl ammonium chloride of ClNO, add NaOH to adjust the pH to 9-10, raise the temperature to 70-90°C, stir and react for 8-16h, after the reaction is completed, dialyze and freeze-dry to obtain antibacterial modified chitosan; (4) Add polypropylene, maleic anhydride grafted polypropylene and antioxidant 168 into a torque rheometer, add antibacterial modified chitosan at 100-120°C, then mix at 200-240°C for 10-30 minutes, and then perform melt spinning to obtain antibacterial chitosan modified polypropylene fibers.

2. The antibacterial chitosan modified polypropylene fiber according to claim 1, characterized in that: The mixed solvent in step (2) is a mixed solvent of N,N-dimethylacetamide and dichloromethane in a mass ratio of 100:80-150.

3. The antibacterial chitosan modified polypropylene fiber according to claim 1, characterized in that: In the step (2), the mass ratio of chlorinated chitosan, phenylisothiazol-3-one and pyridine is 100:18-40:15-30.

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

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

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

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