Nanometer antibacterial polyester masterbatch and its extrusion preparation method

Abstract

The application discloses nano-antibacterial polyester masterbatch and an extrusion preparation method thereof, and belongs to the technical field of polyester masterbatch preparation. The nano-antibacterial polyester masterbatch is composed of the following components in parts by weight: 50-70 parts of polybutylene terephthalate, 10-22 parts of a nano-antibacterial agent, 5-10 parts of a composite anti-yellowing agent, 0.5-1.2 parts of a dispersing agent, 1-3 parts of a lubricant, 6-9 parts of a filler and 0.3-0.6 parts of a plasticizer, wherein the nano-antibacterial agent is prepared from o-phenylenediamine, 2-thiophene formaldehyde, bromine propargyl, 4-fluorochlorobenzyl and sodium azide, and the composite anti-yellowing agent is prepared from 4-hydroxyacetophenone, benzaldehyde, 1,3-dibromopropane, 4-[(methylamino)methyl]piperidine-1-carboxylic acid tert-butyl ester and p-methoxybenzenesulfonyl chloride. The polyester masterbatch prepared by the method has excellent antibacterial performance and anti-aging performance.

Description

Technical Field

[0001] This invention belongs to the field of polyester masterbatch preparation technology, specifically relating to nano-antibacterial polyester masterbatch and its extrusion preparation method. Background Technology

[0002] With the rapid development of industries such as medical, food packaging, and household goods, ordinary polyester products face problems such as high risk of cross-infection and short product life due to their susceptibility to bacteria, mold, and other microorganisms. There is an urgent need for materials with long-lasting antibacterial properties. Traditional antibacterial technologies often involve physical blending or surface coating with antibacterial agents, but these methods suffer from uneven dispersion, easy peeling, and poor durability, making it difficult to meet the demands of high hygiene standards.

[0003] By uniformly dispersing nanoscale antibacterial agents within a polyester matrix, a stable and durable antibacterial structure can be formed. The small size effect and high surface activity of nanoparticles enable them to efficiently disrupt microbial cell membranes and interfere with metabolic processes, achieving broad-spectrum antibacterial functionality. Simultaneously, the nano-antibacterial masterbatch is seamlessly compatible with polyester processing techniques, allowing direct application in spinning, injection molding, and other stages. This significantly improves the processing stability and application versatility of antibacterial materials, making it an important development direction in the field of modern functional materials.

[0004] Patent CN107880500B discloses a silver-based antibacterial polyester masterbatch and its preparation method, prepared by weight of the following components: 78-88 parts resin carrier, 10-20 parts antibacterial agent, 1-2 parts dispersant, 0.3-0.4 parts antioxidant, and 0.5-1 parts stabilizer. The silver-based antibacterial polyester masterbatch of this invention has low production cost, good spinnability, and can be used to spin polyester filaments. The prepared polyester filament products have stable quality and good antibacterial properties. Although the above patent possesses certain antibacterial properties and spinnability, practical applications have revealed room for improvement in its antibacterial performance and resistance to yellowing. Regarding antibacterial properties, the existing antibacterial agents have insufficient dispersion uniformity in the resin carrier and insufficient bonding strength with the resin, resulting in uneven concentrations of antibacterial components in some areas, affecting the overall antibacterial effect. In terms of resistance to yellowing, the compatibility and stabilizing effect of the stabilizer with the resin system are limited. Under long-term use or light exposure, the resin is prone to oxidative degradation, leading to yellowing. Therefore, optimizing the antibacterial agent dispersion process, improving the binding force between the antibacterial agent and the resin, and developing more suitable stabilizers to enhance their compatibility and stabilizing effect with the resin can further improve the antibacterial properties and yellowing resistance of antibacterial polyester masterbatch. Summary of the Invention

[0005] The purpose of this invention is to provide nano-antibacterial polyester masterbatch and its extrusion preparation method, in order to solve the technical problems of poor antibacterial properties and yellowing resistance of polyester masterbatch in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a nano-antibacterial polyester masterbatch, composed of the following components by weight: 50-70 parts polybutylene terephthalate, 10-22 parts nano-antibacterial agent, 5-10 parts composite anti-yellowing agent, 0.5-1.2 parts dispersant, 1-3 parts lubricant, 6-9 parts filler, and 0.3-0.6 parts plasticizer. The nano-antibacterial agent is prepared from o-phenylenediamine, 2-thiophenecarboxaldehyde, bromopropyne, 4-fluorochlorobenzyl, and sodium azide. The composite anti-yellowing agent is prepared from 4-hydroxyacetophenone, benzaldehyde, 1,3-dibromopropane, 4-[(methylamino)methyl]piperidine-1-carboxylic acid tert-butyl ester, and p-methoxybenzenesulfonyl chloride.

[0007] Preferably, the preparation method of the nano-antibacterial agent includes the following steps: Q1: Add o-phenylenediamine, 2-thiophenecarboxaldehyde, and sodium metabisulfite to a container, grind and mix them, and then react them under microwave irradiation. After the reaction is complete, purify and dry to obtain organic compound 1. Add organic compound 1, anhydrous potassium carbonate, and N,N-dimethylformamide to a container, stir evenly, add bromopropyne dropwise, stir, and then heat to react. After the reaction is complete, adjust the pH, and then add it to a container filled with ice water. Filter, wash, and dry to obtain organic compound 2. Q2: Add 4-fluorobenzyl chloride and N,N-dimethylformamide to a container, stir and mix, add sodium azide, heat and react. After the reaction is complete, organic compound 3 is obtained. Q3: Add organic compound 2 to a container containing organic compound 3, stir and mix, then add an aqueous solution containing sodium ascorbate and copper acetate, stir and react. After the reaction is complete, extract, wash, dry, rotary evaporate, and purify to obtain nano antibacterial agent.

[0008] The synthesis reaction formula for the nano-antibacterial agent in the above process is as follows:

[0009] The mass spectrometry analysis results for organic compound 1 were: m / z: 200.04 (100.0%), 201.04 (13.4%), 202.04 (4.7%); for organic compound 2: m / z: 238.06 (100.0%), 239.06 (16.1%), 240.05 (4.5%), 240.06 (1.3%); for organic compound 3: m / z: 151.05 (100.0%), 152.06 (7.6%), 152.05 (1.1%); and for the nano-antibacterial agent: m / z: 389.11 (100.0%), 390.11 (25.4%), 391.11 (5.2%), 391.12. (2.5%), 392.11 (1.1%).

[0010] Preferably, in Q1, the molar ratio of o-phenylenediamine, 2-thiophenecarboxaldehyde, and sodium metabisulfite is (0.98-1.04):(1.05-1.12):(0.93-1.01); the molar ratio of organic compound 1 and bromopropyne is (0.98-1.24):(1.11-1.38); the reaction temperature is raised to 50-53℃; and the pH is adjusted to 7-7.2.

[0011] Preferably, in Q2, the molar ratio of 4-fluorobenzyl chloride to sodium azide is (0.92-1.21):(0.87-1.24), and the temperature is raised to 80-82℃.

[0012] Preferably, in Q3, the molar ratio of organic compound 2 to organic compound 3 is (0.92-1.06):(0.95-1.12), and the mixture is extracted with ethyl acetate, washed sequentially with saturated sodium chloride solution and distilled water, and dried with anhydrous sodium sulfate.

[0013] Preferably, the preparation method of the composite anti-yellowing agent includes the following steps: S1: Add 4-hydroxyacetophenone, benzaldehyde and ethanol to a container, stir and mix, add sodium hydroxide aqueous solution, stir and react. After the reaction is complete, add to ice water, adjust pH, precipitate solid, filter under reduced pressure, recrystallize, filter under vacuum, dry to obtain intermediate a; S2: Add intermediate a, potassium carbonate and acetonitrile to a container, stir and reflux to react, then add 1,3-dibromopropane, continue to heat and reflux to react, after the reaction is completed, add to ice water, a white solid precipitates, filter, wash, filter again, dry to obtain intermediate b; S3: 4-[(methylamino)methyl]piperidine-1-carboxylic acid tert-butyl ester was added to a container containing dichloromethane, stirred, and then triethylamine was added. After reacting in an ice bath, p-methoxybenzenesulfonyl chloride was added dropwise, and the reaction was continued with stirring in an ice bath. After the reaction was completed, the solid was distilled, washed, and dried to obtain intermediate c. Intermediate c, hydrochloric acid, and ethanol were added to a container, and the mixture was heated under reflux. After the reaction was completed, the mixture was evaporated and concentrated, purified, and dried to obtain intermediate d. S4: Add intermediate d, potassium carbonate and acetonitrile to a container, heat and reflux, then add intermediate b, continue heating and reflux reaction. After the reaction is complete, filter, wash, combine organic phases, concentrate under reduced pressure, purify, distill under reduced pressure, and dry to obtain composite anti-yellowing agent.

[0014] The synthesis reaction formula for the composite anti-yellowing agent in the above process is as follows:

[0015] The mass spectrometry analysis results of intermediate a were: m / z: 224.08 (100.0%), 225.09 (16.4%), 226.09 (1.7%); the mass spectrometry analysis results of intermediate b were: m / z: 344.04 (100.0%), 346.04 (97.3%), 345.04 (19.5%), 347.04 (19.0%), 346.05 (2.3%), 348.05 (1.8%); the mass spectrometry analysis results of intermediate c were: m / z: 398.19 (100.0%), 399.19 (21.9%), 400.18 (4.5%), 400.19 (3.4%). 401.19 (1.0%); The mass spectrometry analysis results of intermediate d were: m / z: 298.14 (100.0%), 299.14 (15.5%), 300.13 (4.5%), 300.14 (2.0%), 299.13 (1.5%); The mass spectrometry analysis results of the composite anti-yellowing agent were: m / z: 562.25 (100.0%), 563.25 (36.3%), 564.25 (6.1%), 564.26 (6.0%), 565.25 (1.7%), 565.26 (1.1%).

[0016] Preferably, in step S1, the molar ratio of 4-hydroxyacetophenone to benzaldehyde is (2.201-2.412):(2.641-2.846), the mass fraction of the sodium hydroxide aqueous solution is 5wt%, and the pH is adjusted to 4-4.2 with 5% dilute hydrochloric acid; in step S2, the molar ratio of intermediate a, potassium carbonate, and 1,3-dibromopropane is (2.98-3.84):(0.95-1.32):(2.95-3.81), and the mixture is heated to 82-88℃ and refluxed for 1-2 hours.

[0017] Preferably, in S3, the molar ratio of tert-butyl 4-[(methylamino)methyl]piperidine-1-carboxylate to p-methoxybenzenesulfonyl chloride is (4.88-4.95):(5.35-5.58), and the reaction is continued with stirring for 1-2 hours; the molar ratio of intermediate c to hydrochloric acid is (2.32-2.39):(33.11-33.24), and the mixture is heated to 70-73°C and refluxed.

[0018] Preferably, in step S4, the molar ratio of intermediate d, potassium carbonate and intermediate b is (2.31-2.46):(6.88-7.32):(2.81-2.96), and the mixture is heated to 80-83°C and refluxed for 1-2 hours.

[0019] Preferably, the extrusion preparation method of the nano-antibacterial polyester masterbatch includes the following steps: Step 1: After vacuum drying, polybutylene terephthalate is added to a mixer, followed by the addition of nano antibacterial agent, composite anti-yellowing agent, dispersant, lubricant, filler and plasticizer in sequence. After stirring and mixing, a mixture is obtained. Step 2: Add the mixture to the extruder, extrude, stretch, cool, pelletize and screen to obtain nano antibacterial polyester masterbatch.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention applies the prepared nano-antibacterial agent and composite anti-yellowing agent to the preparation process of polyester masterbatch, which can effectively improve its antibacterial properties and aging resistance.

[0021] 2. In this invention, the prepared nano-antibacterial agent is added to the polyester masterbatch during its preparation process, which can effectively improve its antibacterial performance. The triazole, benzimidazole and thiophene structures contained in the nano-antibacterial agent electrostatically adsorb and destroy the negatively charged microbial cell membrane through their cationic properties. The hydrophobic aromatic ring structure inserts into the membrane lipid layer, synergistically disrupting the membrane integrity and causing leakage of contents. Moreover, the nanoscale ensures that it is uniformly dispersed in the polyester matrix, allowing the nano-antibacterial agent to slowly migrate to the surface and achieve a long-lasting antibacterial effect.

[0022] 3. The present invention adds the prepared composite anti-yellowing agent to the preparation process of polyester masterbatch, which can effectively improve its anti-aging performance. The chalcone structure contained in the composite anti-yellowing agent can effectively absorb high-energy ultraviolet light, and its synergistic effect with the piperidine structure can effectively quench the high-energy excitation strip, preventing the polyester masterbatch from undergoing subsequent cracking or free radical generation reaction. At the same time, the piperidine structure can also act as a regenerable and cyclical free radical scavenger, efficiently terminating the free radical chain reaction that leads to the degradation and yellowing of polyester masterbatch, thus giving it excellent anti-aging ability. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: This example discloses a method for preparing a nano-antibacterial agent, including the following steps: Q1: Add 1.09g of o-phenylenediamine, 1.22g of 2-thiophenecarboxaldehyde, and 1.844g of sodium metabisulfite to a container, grind and mix, then react under microwave irradiation. After the reaction is complete, purify and dry to obtain organic compound 1. Add 1.11g of organic compound 1, 0.12g of anhydrous potassium carbonate, and 12mL of N,N-dimethylformamide to a container, stir evenly, then add 0.741g of bromopropyne dropwise, stir, and heat to 50℃ to react. After the reaction is complete, adjust the pH to 7, then add to a container filled with ice water, filter, wash, and dry to obtain organic compound 2. Q2: Add 3.08g of 4-fluorobenzyl chloride and 12mL of N,N-dimethylformamide to a container, stir and mix, then add 1.37g of sodium azide, heat to 82℃ and react. After the reaction is complete, organic compound 3 is obtained. Q3: Add 1.57g of organic compound 2 to a container containing 1.17g of organic compound 3, stir and mix, then add 10mL of an aqueous solution containing 0.12g of sodium ascorbate and 0.16g of copper acetate, stir and react. After the reaction is complete, extract with ethyl acetate, wash with saturated sodium chloride solution and distilled water in sequence, dry with anhydrous sodium sulfate, rotary evaporate, and purify to obtain nano antibacterial agent.

[0025] This embodiment discloses a method for preparing a composite anti-yellowing agent, including the following steps: S1: 1.57g of 4-hydroxyacetophenone, 1.456g of benzaldehyde and 70mL of ethanol were added to a container and stirred. After mixing, 35mL of 5wt% sodium hydroxide aqueous solution was added and the mixture was stirred. After the reaction was completed, the mixture was added to ice water and the pH was adjusted to 4 with 5% dilute hydrochloric acid. The solid precipitated, filtered under reduced pressure, recrystallized, filtered under vacuum, and dried to obtain intermediate a. S2: 1.522g of intermediate a, 0.31g of potassium carbonate and 75mL of acetonitrile were added to a container and stirred and refluxed at 85°C for 1h. Then 1.365g of 1,3-dibromopropane was added and the mixture was heated to 85°C and refluxed for 2h. After the reaction was completed, the mixture was added to ice water and a white solid precipitated. The solid was filtered, washed, filtered again, and dried to obtain intermediate b. S3: 1.122 g of tert-butyl 4-[(methylamino)methyl]piperidine-1-carboxylate was added to a container containing 20 mL of dichloromethane and stirred. 0.7 mL of triethylamine was added, and the reaction was carried out in an ice bath. Then, 1.13 g of p-methoxybenzenesulfonyl chloride was added dropwise, and the reaction was continued in an ice bath with stirring for 2 h. After the reaction was completed, the solid was distilled, washed, and dried to obtain intermediate c. 0.937 g of intermediate c, 1.194 g of hydrochloric acid, and 20 mL of ethanol were added to a container and heated to 70 °C under reflux. After the reaction was completed, the mixture was evaporated, concentrated, purified, and dried to obtain intermediate d. S4: Add 0.89g of intermediate d, 1.283g of potassium carbonate and 30mL of acetonitrile to a container, heat to 80℃ and reflux for 2h, then add 1.246g of intermediate b, continue heating and reflux reaction. After the reaction is completed, filter, wash, combine organic phases, concentrate under reduced pressure, purify, distill under reduced pressure and dry to obtain composite anti-yellowing agent.

[0026] This embodiment discloses a nano-antibacterial polyester masterbatch, which is composed of the following components by weight: 60 parts polybutylene terephthalate, 16 parts nano-antibacterial agent, 7.5 parts composite anti-yellowing agent, 0.85 parts silane coupling agent KH-550, 2 parts calcium stearate, 7.5 parts nano-silica, and 0.45 parts dioctyl phthalate.

[0027] This embodiment discloses an extrusion preparation method for nano-antibacterial polyester masterbatch, including the following steps: Step 1: After vacuum drying, polybutylene terephthalate is added to a mixer, followed by the addition of nano antibacterial agent, composite anti-yellowing agent, silane coupling agent KH-550, calcium stearate, nano silica and dioctyl phthalate. After stirring and mixing, a mixture is obtained. Step 2: Add the mixture to the extruder, extrude, stretch, cool, pelletize and screen to obtain nano antibacterial polyester masterbatch.

[0028] Example 2: This example discloses a method for preparing a nano-antibacterial agent, including the following steps: Q1: Add 1.06g of o-phenylenediamine, 1.18g of 2-thiophenecarboxaldehyde and 1.768g of sodium metabisulfite to a container, grind and mix, then react under microwave irradiation. After the reaction is complete, purify and dry to obtain organic compound 1. Add 0.98g of organic compound 1, 0.12g of anhydrous potassium carbonate and 12mL of N,N-dimethylformamide to a container, stir evenly, then add 0.66g of bromopropyne dropwise, stir and heat to 50℃ to react. After the reaction is complete, adjust the pH to 7, then add to a container containing ice water, filter, wash and dry to obtain organic compound 2. Q2: Add 2.66g of 4-fluorobenzyl chloride and 12mL of N,N-dimethylformamide to a container, stir and mix, then add 1.13g of sodium azide, heat to 82℃ and react. After the reaction is complete, organic compound 3 is obtained. Q3: Add 1.46g of organic compound 2 to a container containing 1.077g of organic compound 3, stir and mix, then add 10mL of an aqueous solution containing 0.12g of sodium ascorbate and 0.16g of copper acetate, stir and react. After the reaction is complete, extract with ethyl acetate, wash with saturated sodium chloride solution and distilled water in sequence, dry with anhydrous sodium sulfate, rotary evaporate, and purify to obtain nano antibacterial agent.

[0029] This embodiment discloses a method for preparing a composite anti-yellowing agent, including the following steps: S1: 1.498g of 4-hydroxyacetophenone, 1.401g of benzaldehyde and 70mL of ethanol were added to a container and stirred. After mixing, 35mL of 5wt% sodium hydroxide aqueous solution was added and the mixture was stirred. After the reaction was completed, the mixture was added to ice water and the pH was adjusted to 4 with 5% dilute hydrochloric acid. The solid precipitated, filtered under reduced pressure, recrystallized, filtered under vacuum, and dried to obtain intermediate a. S2: 1.335g of intermediate a, 0.36g of potassium carbonate and 75mL of acetonitrile were added to a container and stirred and refluxed at 85°C for 1h. Then 1.19g of 1,3-dibromopropane was added and the mixture was heated to 85°C and refluxed for 2h. After the reaction was completed, the mixture was added to ice water, and a white solid precipitated. The solid was filtered, washed, filtered again, and dried to obtain intermediate b. S3: 1.114 g of tert-butyl 4-[(methylamino)methyl]piperidine-1-carboxylate was added to a container containing 20 mL of dichloromethane and stirred. 0.7 mL of triethylamine was added, and the mixture was reacted in an ice bath. Then, 1.106 g of p-methoxybenzenesulfonyl chloride was added dropwise, and the mixture was stirred in an ice bath for 2 h. After the reaction was completed, the solid was distilled, washed, and dried to obtain intermediate c. 0.923 g of intermediate c, 1.192 g of hydrochloric acid, and 20 mL of ethanol were added to a container and heated to 70 °C under reflux. After the reaction was completed, the mixture was evaporated, concentrated, purified, and dried to obtain intermediate d. S4: Add 0.86g of intermediate d, 1.189g of potassium carbonate and 30mL of acetonitrile to a container, heat to 80℃ and reflux for 2h, then add 1.211g of intermediate b, continue heating and reflux reaction. After the reaction is completed, filter, wash, combine organic phases, concentrate under reduced pressure, purify, distill under reduced pressure and dry to obtain composite anti-yellowing agent.

[0030] This embodiment discloses a nano-antibacterial polyester masterbatch, which is composed of the following components by weight: 50 parts polybutylene terephthalate, 10 parts nano-antibacterial agent, 10 parts composite anti-yellowing agent, 0.5 parts silane coupling agent KH-560, 1 part ethylene bis-stearamide, 9 parts nano-active calcium carbonate, and 0.3 parts tributyl acetylacetate.

[0031] This embodiment discloses an extrusion preparation method for nano-antibacterial polyester masterbatch, including the following steps: Step 1: After vacuum drying, polybutylene terephthalate is added to a mixer, followed by the addition of nano antibacterial agent, composite anti-yellowing agent, silane coupling agent KH-560, ethylene bis-stearamide, nano activated calcium carbonate and tributyl acetyl citrate. After stirring and mixing, a mixture is obtained. Step 2: Add the mixture to the extruder, extrude, stretch, cool, pelletize and screen to obtain nano antibacterial polyester masterbatch.

[0032] Example 3: This example discloses a method for preparing a nano-antibacterial agent, including the following steps: Q1: Add 1.12g of o-phenylenediamine, 1.26g of 2-thiophenecarboxaldehyde and 1.92g of sodium metabisulfite to a container, grind and mix, then react under microwave irradiation. After the reaction is complete, purify and dry to obtain organic compound 1. Add 1.24g of organic compound 1, 0.12g of anhydrous potassium carbonate and 12mL of N,N-dimethylformamide to a container, stir evenly, then add 0.821g of bromopropyne dropwise, stir and heat to 50℃ to react. After the reaction is complete, adjust the pH to 7, then add to a container containing ice water, filter, wash and dry to obtain organic compound 2. Q2: Add 3.499g of 4-fluorobenzyl chloride and 12mL of N,N-dimethylformamide to a container, stir and mix, then add 1.61g of sodium azide, heat to 82℃ and react. After the reaction is complete, organic compound 3 is obtained. Q3: Add 1.68g of organic compound 2 to a container containing 1.27g of organic compound 3, stir and mix, then add 10mL of an aqueous solution containing 0.12g of sodium ascorbate and 0.16g of copper acetate, stir and react. After the reaction is complete, extract with ethyl acetate, wash with saturated sodium chloride solution and distilled water in sequence, dry with anhydrous sodium sulfate, rotary evaporate, and purify to obtain nano antibacterial agent.

[0033] This embodiment discloses a method for preparing a composite anti-yellowing agent, including the following steps: S1: 1.642 g of 4-hydroxyacetophenone, 1.51 g of benzaldehyde and 70 mL of ethanol were added to a container and stirred. After mixing, 35 mL of 5 wt% sodium hydroxide aqueous solution was added and the mixture was stirred. After the reaction was completed, the mixture was added to ice water and the pH was adjusted to 4 with 5% dilute hydrochloric acid. The solid precipitated, filtered under reduced pressure, recrystallized, filtered under vacuum, and dried to obtain intermediate a. S2: 1.72g of intermediate a, 0.26g of potassium carbonate and 75mL of acetonitrile were added to a container and stirred and refluxed at 85°C for 1h. Then 1.54g of 1,3-dibromopropane was added and the mixture was heated to 85°C and refluxed for 2h. After the reaction was completed, the mixture was added to ice water, and a white solid precipitated. The solid was filtered, washed, filtered again, and dried to obtain intermediate b. S3: 1.13 g of tert-butyl 4-[(methylamino)methyl]piperidine-1-carboxylate was added to a container containing 20 mL of dichloromethane and stirred. 0.7 mL of triethylamine was added, and the mixture was reacted in an ice bath. Then, 1.153 g of p-methoxybenzenesulfonyl chloride was added dropwise, and the mixture was stirred in an ice bath for 2 h. After the reaction was completed, the solid was distilled, washed, and dried to obtain intermediate c. 0.951 g of intermediate c, 1.197 g of hydrochloric acid, and 20 mL of ethanol were added to a container and heated to 70 °C under reflux. After the reaction was completed, the mixture was evaporated, concentrated, purified, and dried to obtain intermediate d. S4: Add 0.92g of intermediate d, 1.377g of potassium carbonate and 30mL of acetonitrile to a container, heat to 80℃ and reflux for 2h, then add 1.28g of intermediate b, continue heating and reflux reaction. After the reaction is completed, filter, wash, combine organic phases, concentrate under reduced pressure, purify, distill under reduced pressure and dry to obtain composite anti-yellowing agent.

[0034] This embodiment discloses a nano-antibacterial polyester masterbatch, which is composed of the following components by weight: 70 parts polybutylene terephthalate, 22 parts nano-antibacterial agent, 5 parts composite anti-yellowing agent, 1.2 parts zinc stearate, 3 parts magnesium stearate, 6 parts nano-silica, and 0.6 parts polypropylene adipate.

[0035] This embodiment discloses an extrusion preparation method for nano-antibacterial polyester masterbatch, including the following steps: Step 1: After vacuum drying, polybutylene terephthalate is added to a mixer, followed by the addition of nano antibacterial agent, composite anti-yellowing agent, zinc stearate, magnesium stearate, nano silica and polypropylene adipate in sequence. After stirring and mixing, a mixture is obtained. Step 2: Add the mixture to the extruder, extrude, stretch, cool, pelletize and screen to obtain nano antibacterial polyester masterbatch.

[0036] Example 4: This example discloses a method for preparing a nano-antibacterial agent, including the following steps: Q1: Add 1.07g of o-phenylenediamine, 1.21g of 2-thiophenecarboxaldehyde and 1.812g of sodium metabisulfite to a container, grind and mix, then react under microwave irradiation. After the reaction is complete, purify and dry to obtain organic compound 1. Add 1.06g of organic compound 1, 0.12g of anhydrous potassium carbonate and 12mL of N,N-dimethylformamide to a container, stir evenly, then add 0.683g of bromopropyne dropwise, stir and heat to 50℃ to react. After the reaction is complete, adjust the pH to 7, then add to a container containing ice water, filter, wash and dry to obtain organic compound 2. Q2: Add 2.87g of 4-fluorobenzyl chloride and 12mL of N,N-dimethylformamide to a container, stir and mix, then add 1.25g of sodium azide, heat to 82℃ and react. After the reaction is complete, organic compound 3 is obtained. Q3: Add 1.48g of organic compound 2 to a container containing 1.093g of organic compound 3, stir and mix, then add 10mL of an aqueous solution containing 0.12g of sodium ascorbate and 0.16g of copper acetate, stir and react. After the reaction is complete, extract with ethyl acetate, wash with saturated sodium chloride solution and distilled water in sequence, dry with anhydrous sodium sulfate, rotary evaporate, and purify to obtain nano antibacterial agent.

[0037] This embodiment discloses a method for preparing a composite anti-yellowing agent, including the following steps: S1: 1.527g of 4-hydroxyacetophenone, 1.422g of benzaldehyde and 70mL of ethanol were added to a container and stirred. After mixing, 35mL of 5wt% sodium hydroxide aqueous solution was added and the mixture was stirred. After the reaction was completed, the mixture was added to ice water and the pH was adjusted to 4 with 5% dilute hydrochloric acid. The solid precipitated, filtered under reduced pressure, recrystallized, filtered under vacuum, and dried to obtain intermediate a. S2: 1.48 g of intermediate a, 0.33 g of potassium carbonate and 75 mL of acetonitrile were added to a container and stirred and refluxed at 85 °C for 1 h. Then 1.28 g of 1,3-dibromopropane was added and the mixture was heated to 85 °C and refluxed for 2 h. After the reaction was completed, the mixture was added to ice water and a white solid precipitated. The solid was filtered, washed, filtered again, and dried to obtain intermediate b. S3: 1.118 g of tert-butyl 4-[(methylamino)methyl]piperidine-1-carboxylate was added to a container containing 20 mL of dichloromethane and stirred. 0.7 mL of triethylamine was added, and the mixture was reacted in an ice bath. Then, 1.109 g of p-methoxybenzenesulfonyl chloride was added dropwise, and the mixture was stirred in an ice bath for 2 h. After the reaction was completed, the solid was distilled, washed, and dried to obtain intermediate c. 0.931 g of intermediate c, 1.193 g of hydrochloric acid, and 20 mL of ethanol were added to a container and heated to 70 °C under reflux. After the reaction was completed, the mixture was evaporated, concentrated, purified, and dried to obtain intermediate d. S4: Add 0.88g of intermediate d, 1.199g of potassium carbonate and 30mL of acetonitrile to a container, heat to 80℃ and reflux for 2h, then add 1.228g of intermediate b, continue heating and reflux reaction. After the reaction is completed, filter, wash, combine organic phases, concentrate under reduced pressure, purify, distill under reduced pressure and dry to obtain composite anti-yellowing agent.

[0038] This embodiment discloses a nano-antibacterial polyester masterbatch, which is composed of the following components by weight: 55 parts polybutylene terephthalate, 13 parts nano-antibacterial agent, 6 parts composite anti-yellowing agent, 0.7 parts oxidized polyethylene wax, 1.5 parts calcium stearate, 7 parts nano-activated calcium carbonate, and 0.4 parts tributyl acetylacetate.

[0039] This embodiment discloses an extrusion preparation method for nano-antibacterial polyester masterbatch, including the following steps: Step 1: After vacuum drying, polybutylene terephthalate is added to a mixer, followed by the addition of nano antibacterial agent, composite anti-yellowing agent, oxidized polyethylene wax, calcium stearate, nano activated calcium carbonate and tributyl acetyl citrate. After stirring and mixing, a mixture is obtained. Step 2: Add the mixture to the extruder, extrude, stretch, cool, pelletize and screen to obtain nano antibacterial polyester masterbatch.

[0040] Comparative Example 1: Compared with Example 1, Comparative Example 1 did not add nano-antibacterial agent during the preparation of nano-antibacterial polyester masterbatch, and all other conditions remained unchanged.

[0041] Comparative Example 2: Compared with Example 1, Comparative Example 2 did not add a composite anti-yellowing agent during the preparation of nano-antibacterial polyester masterbatch, and all other conditions remained unchanged.

[0042] Performance testing: The nano-antibacterial polyester masterbatches prepared according to Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests. The antibacterial properties of the samples were tested according to GB / T 31402-2023, the samples were treated according to GB / T 16422.2-2022, and the whiteness of the samples before and after treatment was tested according to GB / T 2913-1982. The test results are shown in Table 1. As shown in Table 1, the test results indicate that polyester masterbatches with excellent antibacterial and yellowing resistance can be prepared using the methods described in Examples 1-4. A comparison between Comparative Example 1 and Examples 1-4 reveals that the addition of nano-antibacterial agents effectively improves the antibacterial properties of the polyester masterbatch; a comparison between Comparative Example 2 and Examples 1-4 shows that the addition of composite anti-yellowing agents effectively improves the yellowing resistance of the polyester masterbatch.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0044] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. Nano-antibacterial polyester masterbatch, characterized in that, It is composed of the following components by weight: 50-70 parts polybutylene terephthalate, 10-22 parts nano antibacterial agent, 5-10 parts composite anti-yellowing agent, 0.5-1.2 parts dispersant, 1-3 parts lubricant, 6-9 parts filler, and 0.3-0.6 parts plasticizer. The nano antibacterial agent is prepared from o-phenylenediamine, 2-thiophenecarboxaldehyde, bromopropyne, 4-fluorochlorobenzyl, and sodium azide. The composite anti-yellowing agent is prepared from 4-hydroxyacetophenone, benzaldehyde, 1,3-dibromopropane, 4-[(methylamino)methyl]piperidine-1-carboxylic acid tert-butyl ester, and p-methoxybenzenesulfonyl chloride.

2. The nano-antibacterial polyester masterbatch according to claim 1, characterized in that, The preparation method of the nano-antibacterial agent includes the following steps: Q1: Add o-phenylenediamine, 2-thiophenecarboxaldehyde, and sodium metabisulfite to a container, grind and mix them, and then react them under microwave irradiation. After the reaction is complete, purify and dry to obtain organic compound 1. Add organic compound 1, anhydrous potassium carbonate, and N,N-dimethylformamide to a container, stir evenly, add bromopropyne dropwise, stir, and then heat to react. After the reaction is complete, adjust the pH, and then add it to a container filled with ice water. Filter, wash, and dry to obtain organic compound 2. Q2: Add 4-fluorobenzyl chloride and N,N-dimethylformamide to a container, stir and mix, add sodium azide, heat and react. After the reaction is complete, organic compound 3 is obtained. Q3: Add organic compound 2 to a container containing organic compound 3, stir and mix, then add an aqueous solution containing sodium ascorbate and copper acetate, stir and react. After the reaction is complete, extract, wash, dry, rotary evaporate, and purify to obtain nano antibacterial agent.

3. The nano-antibacterial polyester masterbatch according to claim 2, characterized in that, In Q1, the molar ratio of o-phenylenediamine, 2-thiophenecarboxaldehyde and sodium metabisulfite is (0.98-1.04):(1.05-1.12):(0.93-1.01); the molar ratio of organic compound 1 and bromopropyne is (0.98-1.24):(1.11-1.38).

4. The nano-antibacterial polyester masterbatch according to claim 2, characterized in that, In Q2, the molar ratio of 4-fluorobenzyl chloride to sodium azide is (0.92-1.21):(0.87-1.24).

5. The nano-antibacterial polyester masterbatch according to claim 2, characterized in that, In Q3, the molar ratio of organic compound 2 to organic compound 3 is (0.92-1.06):(0.95-1.12).

6. The nano-antibacterial polyester masterbatch according to claim 1, characterized in that, The preparation method of the composite anti-yellowing agent includes the following steps: S1: Add 4-hydroxyacetophenone, benzaldehyde and ethanol to a container, stir and mix, add sodium hydroxide aqueous solution, stir and react. After the reaction is complete, add to ice water, adjust pH, precipitate solid, filter under reduced pressure, recrystallize, filter under vacuum, dry to obtain intermediate a; S2: Add intermediate a, potassium carbonate and acetonitrile to a container, stir and reflux to react, then add 1,3-dibromopropane, continue to heat and reflux to react, after the reaction is completed, add to ice water, a white solid precipitates, filter, wash, filter again, dry to obtain intermediate b; S3: 4-[(methylamino)methyl]piperidine-1-carboxylic acid tert-butyl ester was added to a container containing dichloromethane, stirred, and then triethylamine was added. After reacting in an ice bath, p-methoxybenzenesulfonyl chloride was added dropwise, and the reaction was continued with stirring in an ice bath. After the reaction was completed, the solid was distilled, washed, and dried to obtain intermediate c. Intermediate c, hydrochloric acid, and ethanol were added to a container, and the mixture was heated under reflux. After the reaction was completed, the mixture was evaporated and concentrated, purified, and dried to obtain intermediate d. S4: Add intermediate d, potassium carbonate and acetonitrile to a container, heat and reflux, then add intermediate b, continue heating and reflux reaction. After the reaction is complete, filter, wash, combine organic phases, concentrate under reduced pressure, purify, distill under reduced pressure, and dry to obtain composite anti-yellowing agent.

7. The nano-antibacterial polyester masterbatch according to claim 6, characterized in that, In S1, the molar ratio of 4-hydroxyacetophenone to benzaldehyde is (2.201-2.412):(2.641-2.846); in S2, the molar ratio of intermediate a, potassium carbonate and 1,3-dibromopropane is (2.98-3.84):(0.95-1.32):(2.95-3.81).

8. The nano-antibacterial polyester masterbatch according to claim 6, characterized in that, In S3, the molar ratio of tert-butyl 4-[(methylamino)methyl]piperidine-1-carboxylate to p-methoxybenzenesulfonyl chloride is (4.88-4.95):(5.35-5.58); the molar ratio of intermediate c to hydrochloric acid is (2.32-2.39):(33.11-33.24).

9. The nano-antibacterial polyester masterbatch according to claim 6, characterized in that, In S4, the molar ratio of intermediate d, potassium carbonate and intermediate b is (2.31-2.46):(6.88-7.32):(2.81-2.96).

10. The extrusion preparation method of the nano-antibacterial polyester masterbatch according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: After vacuum drying, polybutylene terephthalate is added to a mixer, followed by the addition of nano antibacterial agent, composite anti-yellowing agent, dispersant, lubricant, filler and plasticizer in sequence. After stirring and mixing, a mixture is obtained. Step 2: Add the mixture to the extruder, extrude, stretch, cool, pelletize and screen to obtain nano antibacterial polyester masterbatch.

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