Antibacterial polylactic acid fiber as well as preparation method and application thereof
By introducing an antibacterial agent formed by imidazole chloride and furanamine into polylactic acid fiber and the synergistic effect of tannic acid-modified nano zinc oxide, the problem of poor antibacterial effect of polylactic acid fiber under high temperature and high humidity environment is solved, and high-efficiency antibacterial performance is achieved.
Patent Information
- Application Number
- CN202511775357.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-01-27
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polylactic acid fiber technology, specifically relating to an antibacterial polylactic acid fiber, its preparation method, and its application. Background Technology
[0002] Polylactic acid (PLA) fiber is a biodegradable synthetic fiber made from plant materials such as corn through fermentation and polymerization. It has good environmental protection properties and is widely used in the medical, food and agricultural fields.
[0003] Polylactic acid (PLA) fiber is naturally slightly acidic, with a pH value close to that of human skin. Fabrics made from PLA are more skin-friendly than those made from other fibers, and its natural antibacterial properties also help prevent mites and mildew. During use, it releases lactic acid, creating an acidic environment that inhibits bacterial growth. However, its antibacterial effect is limited, requiring the addition of antibacterial agents to create composite fibers to enhance its antibacterial properties.
[0004] Current antibacterial agents mainly include inorganic and organic antibacterial agents. Inorganic antibacterial agents have good antibacterial properties and stability, but their cost is relatively high. Some metal oxide antibacterial agents (such as TiO2) are catalytic antibacterial agents, requiring specific ultraviolet irradiation conditions to achieve better antibacterial effects. Some nanoparticles are also prone to aggregation, affecting their antibacterial efficacy. Organic antibacterial agents mainly include quaternary ammonium salts, organometallic compounds, alcohols, and phenols. While these antibacterial agents have good antibacterial effects, they lack good heat resistance, affecting their antibacterial efficacy at high temperatures. In summary, current antibacterial agents cannot guarantee high-efficiency antibacterial effects for polylactic acid (PLA) fibers at high temperatures. High temperature and high humidity environments provide ideal growth conditions for microorganisms, easily leading to mold growth, odors, and reduced wearing comfort. Therefore, developing PLA fibers with sustained antibacterial properties under high temperature and high humidity is of great significance for improving the practical value of PLA fiber fabrics. Summary of the Invention
[0005] This invention provides an antibacterial polylactic acid fiber, its preparation method, and its application, which can solve the problem of poor long-term antibacterial effect of polylactic acid fiber under high temperature and high humidity in the prior art.
[0006] The objective of this invention can be achieved through the following technical solutions: An antibacterial polylactic acid fiber, comprising the following raw materials by weight: 50-70 parts polylactic acid chips, 15-25 parts antibacterial agent, 5-15 parts tannic acid modified nano zinc oxide, and 3-8 parts lubricant; The antibacterial agent is a polylactic acid graft compound formed by introducing imidazole chloride and furanamine onto the side chain of the polylactic acid molecular chain.
[0007] Furthermore, the method for preparing the antibacterial agent includes the following steps: S1. Dissolve polylactic acid in chloroform to form a polylactic acid solution, add 1-carboxymethyl-3-vinylimidazolium chloride, and react with gamma ray irradiation. S2. After the reaction is complete, methanol is added as a precipitant to produce a precipitate. After filtration, the filter residue is dried to obtain imidazole chloride-grafted polylactic acid. S3. Add imidazole chloride-grafted polylactic acid to dichloromethane, stir until completely dissolved, add 2,5-furandimethylamine, activator and catalyst, and react at room temperature for 24-48 hours. S4. After the reaction is complete, the mixture is extracted with a saturated sodium chloride aqueous solution. The organic phase is then removed by rotary evaporation to remove the solvent, and the antibacterial agent is obtained.
[0008] Under gamma irradiation, the methylene groups in the main chain of polylactic acid (PLA) undergo dehydrogenation, forming large molecular free radicals. These radicals initiate a grafting reaction of imidazole chloride salts with unsaturated double bonds, introducing imidazole chloride salts onto the PLA side chains. With the aid of an activator, the carbonyl group on the carboxyl group of the imidazole chloride salt is activated, reacting with an amino group on one side of the highly reactive 2,5-furandimethylamine to form an amide bond. This introduces aromatic groups (furan rings) onto the imidazole chloride salt side chains, improving its thermal stability and preventing the oxidative decomposition of organic imidazole salts.
[0009] Furthermore, the concentration of the polylactic acid solution is 2-5 g / L.
[0010] Furthermore, the 1-carboxymethyl-3-vinylimidazolium chloride is 25-40% of the mass of polylactic acid.
[0011] Furthermore, the radiation source of the gamma rays is cobalt-60, the irradiation dose rate is 2-2.5 kGy / h, and the irradiation dose is 8-10 kGy.
[0012] Furthermore, the 2,5-furandimethylamine is 5-8% of the mass of imidazolium chloride grafted polylactic acid.
[0013] Furthermore, the activator is 4-dimethylaminopyridine, and the catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; The activator is 6-10% by mass of imidazole chloride-grafted polylactic acid; The catalyst is 15-20% of the mass of imidazolium chloride-grafted polylactic acid.
[0014] Furthermore, the preparation method of the tannic acid-modified nano zinc oxide includes the following steps: A1. Add zinc acetate to ethanol, stir to dissolve and form a solution, add tannic acid to the solution, seal and heat to 110-120℃ and react at a constant temperature for 10-12 hours; A2. After the reaction is complete, the precipitate is collected by centrifugation, washed, and then freeze-dried to obtain tannic acid modified nano zinc oxide.
[0015] Zinc acetate is thermally decomposed in ethanol solvent to synthesize zinc oxide. During the synthesis process, tannic acid oxygen is added to modify zinc oxide through coordination bonds, resulting in abundant phenolic hydroxyl groups on the surface of zinc oxide. The highly active phenolic hydroxyl groups combine with the amino group on the other side of the furan ring on the side chain of the antibacterial agent through Schiff base reaction, promoting the dispersion of inorganic antibacterial particles.
[0016] Further, in step A1, the concentration of zinc acetate in the solution is 0.25-40 mol / L.
[0017] Furthermore, the tannic acid is 2-8% of the mass of zinc acetate.
[0018] Furthermore, the lubricant is one of oxidized polyethylene wax and fatty alcohol polyoxyethylene ether.
[0019] This invention also provides a method for preparing antibacterial polylactic acid fibers, which includes the following steps: Step 1: Weigh the raw materials according to the proportion, melt and blend the raw materials at 180-210℃, and then granulate them; Step 2: The fibers are fed into a melt spinning machine for spinning and then drawn to obtain antibacterial polylactic acid fibers.
[0020] The present invention also provides an application of antibacterial polylactic acid fiber, which is used to prepare clothing and medical textiles.
[0021] The beneficial effects of this invention are: The antibacterial polylactic acid (PLA) fiber provided by this invention contains two antibacterial active components. A highly compatible organic antibacterial agent is formed through a grafting reaction of the PLA molecular chains. Using the antibacterial agent as a bridge, a Schiff base reaction is achieved between the amino groups on the antibacterial agent and the phenolic hydroxyl groups on the tannic acid-modified nano-zinc oxide, ensuring uniform dispersion of the organic and inorganic antibacterial components within the PLA matrix. The reactants and reaction process are optimized during the preparation of the antibacterial agent. First, a highly antibacterial imidazole chloride salt is introduced onto the PLA, followed by the formation of an amide bond from the hydroxyl amino group, introducing an external furan ring and enhancing the heat resistance of the antibacterial agent. This invention achieves dual antibacterial properties (organic and inorganic) through the synergistic effect of the antibacterial agent and the tannic acid-modified nano-zinc oxide, endowing the fiber with highly efficient and long-lasting antibacterial performance under high temperature and high humidity conditions. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0023] Example 1
[0024] Preparation of antibacterial agents: S1. Weigh polylactic acid and add it to chloroform. Stir the solvent to form a polylactic acid solution with a concentration of 4 g / L. Weigh 35% of the mass of polylactic acid, add 1-carboxymethyl-3-vinylimidazolium chloride to the polylactic acid solution, and irradiate the reaction with cobalt-60 source gamma rays while stirring. The irradiation dose rate is 2.3 kGy / h and the irradiation dose is 10 kGy.
[0025] S2. After the reaction is complete, methanol is added as a precipitant to produce a precipitate. After filtration, the filter residue is dried to obtain imidazole chloride-grafted polylactic acid.
[0026] S3. Weigh the imidazole chloride-grafted polylactic acid obtained in step S2, add it to dichloromethane at a mass concentration of 15 g / L, and stir until completely dissolved. Weigh 2,5-furandimethylamine at 6% of the mass of imidazole chloride-grafted polylactic acid, weigh 4-dimethylaminopyridine at 8% of the mass of imidazole chloride-grafted polylactic acid, and weigh 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride at 16% of the mass of imidazole chloride-grafted polylactic acid. Add 2,5-furandimethylamine, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to the system to dissolve the mixture, and stir the mixture at room temperature for 24 h.
[0027] S4. After the reaction is complete, the product is added to a saturated sodium chloride aqueous solution for extraction. The organic phase is then removed by rotary evaporation to remove the solvent, thus obtaining the antibacterial agent.
[0028] Preparation of tannic acid-modified nano zinc oxide: A1. Weigh zinc acetate to a concentration of 0.35 mol / L and add it to ethanol. Stir to dissolve and form a solution. Add tannic acid to the solution, which is 5% of the mass of zinc acetate. Seal the solution and heat it to 120℃ for 12 hours.
[0029] A2. After the reaction is complete, centrifuge at 5000 r / min for 6 min to collect the precipitate, wash it and freeze-dry it to obtain tannic acid modified nano zinc oxide.
[0030] Preparation of antibacterial polylactic acid fibers: Step 1: Weigh the raw materials according to the following mass proportions: 60 parts polylactic acid chips, 20 parts antibacterial agent, 10 parts tannic acid modified nano zinc oxide, and 7 parts oxidized polyethylene wax. Melt and blend the raw materials at 180-210℃ and then granulate.
[0031] Step 2: The fibers are fed into a melt spinning machine for spinning and then drawn to obtain antibacterial polylactic acid fibers.
[0032] Example 2
[0033] The only difference from Example 1 is that, when preparing the antibacterial agent, the 1-carboxymethyl-3-vinylimidazolium chloride is adjusted to 25% of the mass of polylactic acid, while the other steps and conditions are the same as in Example 1.
[0034] Example 3
[0035] The only difference from Example 1 is that, when preparing the antibacterial agent, the 1-carboxymethyl-3-vinylimidazolium chloride is adjusted to 40% of the mass of polylactic acid; the other steps and conditions are the same as in Example 1.
[0036] Example 4
[0037] The only difference from Example 1 is that, when preparing tannic acid-modified nano zinc oxide, the tannic acid is adjusted to 2% of the mass of zinc acetate, and the other steps and conditions are the same as in Example 1.
[0038] Example 5
[0039] The only difference from Example 1 is that, when preparing tannic acid-modified nano zinc oxide, the tannic acid is adjusted to 8% of the mass of zinc acetate, and the other steps and conditions are the same as in Example 1.
[0040] Example 6
[0041] The only difference from Example 1 is that the mass fraction of the antibacterial agent in the raw materials is increased to 25 parts when preparing antibacterial polylactic acid fiber, and the mass fraction of tannic acid modified nano zinc oxide is reduced to 5 parts. Other steps and conditions are the same as in Example 1.
[0042] Example 7
[0043] The only difference from Example 1 is that the mass fraction of the antibacterial agent in the raw materials is reduced to 15 parts when preparing antibacterial polylactic acid fiber, and the mass fraction of tannic acid modified nano zinc oxide is increased to 15 parts. Other steps and conditions are the same as in Example 1.
[0044] Comparative Example 1
[0045] The only difference from Example 1 is that the antibacterial agent in this comparative example does not introduce a furan ring.
[0046] Preparation of antibacterial agents: S1. Weigh polylactic acid and add it to chloroform. Stir the solvent to form a polylactic acid solution with a concentration of 4 g / L. Weigh 35% of the mass of polylactic acid, add 1-carboxymethyl-3-vinylimidazolium chloride to the polylactic acid solution, and irradiate the reaction with cobalt-60 source gamma rays while stirring. The irradiation dose rate is 2.3 kGy / h and the irradiation dose is 10 kGy.
[0047] S2. After the reaction is complete, methanol is added as a precipitant to produce a precipitate. After filtration, the filter residue is dried to obtain imidazole chloride-grafted polylactic acid, which is the antibacterial agent.
[0048] Preparation of tannic acid-modified nano zinc oxide: A1. Weigh zinc acetate to a concentration of 0.35 mol / L and add it to ethanol. Stir to dissolve and form a solution. Add tannic acid to the solution, which is 5% of the mass of zinc acetate. Seal the solution and heat it to 120℃ for 12 hours.
[0049] A2. After the reaction is complete, centrifuge at 5000 r / min for 6 min to collect the precipitate, wash it and freeze-dry it to obtain tannic acid modified nano zinc oxide.
[0050] Preparation of antibacterial polylactic acid fibers: Step 1: Weigh the raw materials according to the following mass proportions: 60 parts polylactic acid chips, 20 parts antibacterial agent, 10 parts tannic acid modified nano zinc oxide, and 7 parts oxidized polyethylene wax. Melt and blend the raw materials at 180-210℃ and then granulate.
[0051] Step 2: The fibers are fed into a melt spinning machine for spinning and then drawn to obtain antibacterial polylactic acid fibers.
[0052] Comparative Example 2
[0053] The only difference from Example 1 is that no antibacterial agent is added in this comparative example; instead, an equal mass of polylactic acid is used to replace the antibacterial agent.
[0054] Preparation of tannic acid-modified nano zinc oxide: A1. Weigh zinc acetate to a concentration of 0.35 mol / L and add it to ethanol. Stir to dissolve and form a solution. Add tannic acid to the solution, which is 5% of the mass of zinc acetate. Seal the solution and heat it to 120℃ for 12 hours.
[0055] A2. After the reaction is complete, centrifuge at 5000 r / min for 6 min to collect the precipitate, wash it and freeze-dry it to obtain tannic acid modified nano zinc oxide.
[0056] Preparation of antibacterial polylactic acid fibers: Step 1: Weigh the raw materials according to the following mass proportions: 80 parts polylactic acid chips, 10 parts tannic acid modified nano zinc oxide, and 7 parts oxidized polyethylene wax. Melt and blend the raw materials at 180-210℃ and then granulate.
[0057] Step 2: The fibers are fed into a melt spinning machine for spinning and then drawn to obtain antibacterial polylactic acid fibers.
[0058] Comparative Example 3
[0059] The only difference from Example 1 is that nano zinc oxide is used instead of tannic acid-modified nano zinc oxide in this comparative example.
[0060] Preparation of antibacterial agents: S1. Weigh polylactic acid and add it to chloroform. Stir the solvent to form a polylactic acid solution with a concentration of 4 g / L. Weigh 35% of the mass of polylactic acid, add 1-carboxymethyl-3-vinylimidazolium chloride to the polylactic acid solution, and irradiate the reaction with cobalt-60 source gamma rays while stirring. The irradiation dose rate is 2.3 kGy / h and the irradiation dose is 10 kGy.
[0061] S2. After the reaction is complete, methanol is added as a precipitant to produce a precipitate. After filtration, the filter residue is dried to obtain imidazole chloride-grafted polylactic acid.
[0062] S3. Weigh the imidazole chloride-grafted polylactic acid obtained in step S2, add it to dichloromethane at a mass concentration of 15 g / L, and stir until completely dissolved. Weigh 2,5-furandimethylamine at 6% of the mass of imidazole chloride-grafted polylactic acid, weigh 4-dimethylaminopyridine at 8% of the mass of imidazole chloride-grafted polylactic acid, and weigh 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride at 16% of the mass of imidazole chloride-grafted polylactic acid. Add 2,5-furandimethylamine, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride to the system to dissolve the mixture, and stir the mixture at room temperature for 24 h.
[0063] S4. After the reaction is complete, the product is added to a saturated sodium chloride aqueous solution for extraction. The organic phase is then removed by rotary evaporation to remove the solvent, thus obtaining the antibacterial agent.
[0064] Preparation of nano zinc oxide: A1. Weigh out zinc acetate at a concentration of 0.35 mol / L and add it to ethanol. Stir to dissolve and form a solution. Seal the solution and heat it to 120℃ for 12 hours.
[0065] A2. After the reaction is complete, centrifuge at 5000 r / min for 6 min to collect the precipitate, wash it and freeze dry to obtain nano zinc oxide.
[0066] Preparation of antibacterial polylactic acid fibers: Step 1: Weigh the raw materials according to the following mass proportions: 60 parts polylactic acid chips, 20 parts antibacterial agent, 10 parts nano zinc oxide, and 7 parts oxidized polyethylene wax. Melt and blend the raw materials at 180-210℃ and then granulate.
[0067] Step 2: The fibers are fed into a melt spinning machine for spinning and then drawn to obtain antibacterial polylactic acid fibers.
[0068] The antibacterial polylactic acid fibers prepared in Examples 1-7 and Comparative Examples 1-3 were subjected to performance tests, and the results are shown in Table 1.
[0069] Antibacterial performance test: The antibacterial rate was determined according to the standard GB / T 20944-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method", with a shaking contact temperature of 24℃±1℃. Antibacterial performance test under high temperature and high humidity: The fibers were placed in a high temperature and high humidity environment (temperature 40℃ / RH 90%) for 7 days before the antibacterial performance was tested.
[0070] Table 1
[0071] As shown in Table 1, the amount of imidazole chloride used in the preparation of the antibacterial agent was adjusted in Examples 1-3. Under gamma irradiation, the grafting rate increased with the increase of the amount of imidazole chloride. However, in Example 3, the excess imidazole chloride would polymerize with each other, preventing it from grafting onto the polylactic acid molecular chain. The grafting rate decreased compared to Example 1, and the antibacterial performance was also slightly reduced accordingly. Examples 4 and 5 differed in the amount of tannic acid modification on the zinc oxide in Example 1. Tannic acid modification is beneficial for the dispersion of inorganic antibacterial components in the polylactic acid matrix. The fiber exhibited the best antibacterial performance under the modification ratio in Example 1. Combining Comparative Example 1 and Example 1, it can be seen that the furan ring introduced into the antibacterial agent has a positive effect on inhibiting the oxidative decomposition of the antibacterial active components under high temperature and high humidity conditions. Furthermore, based on the results of Comparative Examples 2, 3, and Example 1, the antibacterial agent and tannic acid-modified nano-zinc oxide in polylactic acid fibers synergistically endow them with excellent antibacterial properties.
[0072] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0073] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. An antibacterial polylactic acid fiber, characterized in that, By weight, it includes the following raw materials: 50-70 parts polylactic acid chips, 15-25 parts antibacterial agent, 5-15 parts tannic acid modified nano zinc oxide, and 3-8 parts lubricant; The antibacterial agent is a polylactic acid graft compound formed by introducing imidazole chloride and furanamine onto the side chain of the polylactic acid molecular chain.
2. The antibacterial polylactic acid fiber according to claim 1, characterized in that, The method for preparing the antibacterial agent includes the following steps: S1. Dissolve polylactic acid in chloroform to form a polylactic acid solution, add 1-carboxymethyl-3-vinylimidazolium chloride, and react with gamma ray irradiation. S2. After the reaction is complete, methanol is added as a precipitant to produce a precipitate. After filtration, the filter residue is dried to obtain imidazole chloride-grafted polylactic acid. S3. Add imidazole chloride-grafted polylactic acid to dichloromethane, stir until completely dissolved, add 2,5-furandimethylamine, activator and catalyst, and react at room temperature for 24-48 hours. S4. After the reaction is complete, the mixture is extracted with a saturated sodium chloride aqueous solution. The organic phase is then removed by rotary evaporation to remove the solvent, and the antibacterial agent is obtained.
3. The antibacterial polylactic acid fiber according to claim 2, characterized in that, The concentration of the polylactic acid solution is 2-5 g / L.
4. The antibacterial polylactic acid fiber according to claim 2, characterized in that, The 1-carboxymethyl-3-vinylimidazolium chloride is 25-40% of the mass of polylactic acid.
5. The antibacterial polylactic acid fiber according to claim 2, characterized in that, The 2,5-furandimethylamine is 5-8% of the mass of imidazole chloride-grafted polylactic acid.
6. The antibacterial polylactic acid fiber according to claim 2, characterized in that, The activator is 4-dimethylaminopyridine, and the catalyst is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; The activator is 6-10% by mass of imidazole chloride-grafted polylactic acid; The catalyst is 15-20% of the mass of imidazolium chloride-grafted polylactic acid.
7. The antibacterial polylactic acid fiber according to claim 1, characterized in that, The preparation method of the tannic acid modified nano zinc oxide includes the following steps: A1. Add zinc acetate to ethanol, stir to dissolve and form a solution, add tannic acid to the solution, seal and heat to 110-120℃ and react at a constant temperature for 10-12 hours; A2. After the reaction is complete, the precipitate is collected by centrifugation, washed, and then freeze-dried to obtain tannic acid modified nano zinc oxide.
8. The antibacterial polylactic acid fiber according to claim 7, characterized in that, In step A1, the concentration of zinc acetate in the solution is 0.25-40 mol / L; The tannic acid is 2-8% of the mass of zinc acetate.
9. A method for preparing antibacterial polylactic acid fiber, characterized in that, The preparation of antibacterial polylactic acid fiber as described in any one of claims 1-8 comprises the following steps: Step 1: Weigh the raw materials according to the proportion, melt and blend the raw materials at 180-210℃, and then granulate them; Step 2: The fibers are fed into a melt spinning machine for spinning and then drawn to obtain antibacterial polylactic acid fibers.
10. An application of antibacterial polylactic acid fiber, characterized in that, Clothing and medical textiles can be prepared using antibacterial polylactic acid fibers as described in any one of claims 1-8.