Durable antibacterial fully bio-based furan polyesters, methods of making and applications thereof

Abstract

The application relates to a durable antibacterial full-bio-based furan polyester, a preparation method and application thereof, and belongs to the technical field of high polymer materials. The application provides a preparation method of the durable antibacterial full-bio-based furan polyester, which comprises the following steps: adding furan dicarboxylic acid monomers, one or more bio-based dihydric alcohol monomers, a stabilizer, water, an antioxidant and a catalyst into a reaction kettle to perform esterification reaction, obtaining full-bio-based furan polyester esterification products, then performing polycondensation reaction to obtain bio-based furan polyester, finally adding monocarboxyl (trifluoromethyl) thiazole-5-carboxylic acid derivative comonomers as end-capping agents and molecular weight regulators to copolymerize to the end of the bio-based furan polyester macromolecular chain to obtain antibacterial full-bio-based furan polyester. The preparation method is green and environment-friendly, the full-bio-based furan polyester has durable and efficient antibacterial effect, can still maintain high antibacterial property under long-term high-temperature and high-humidity conditions, and has good yellowing resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and particularly relates to a durable antibacterial full-bio-based furan polyester and a preparation method thereof. BACKGROUND

[0002] 2,5-furandicarboxylic acid (FDCA) as a furan derivative extracted from non-food biomass, its structure is highly similar to pure terephthalic acid (PTA), which is an ideal alternative monomer for preparing bio-based polyesters, polyamides and polyurethanes. Polyethylene 2,5-furandicarboxylate (PEF) obtained by polymerization of FDCA and ethylene glycol, has significant advantages in the field of food packaging: its water and oxygen barrier performance is much better than that of traditional polyethylene terephthalate (PET), which can effectively inhibit the growth of aerobic bacteria and prolong the shelf life of food. At present, it has realized application exploration in the field of packaging film and beverage bottle. However, most food spoilage bacteria are anaerobic and facultative anaerobic bacteria (such as Escherichia coli, Staphylococcus aureus, Clostridium and yeast), and only high barrier property cannot completely inhibit the proliferation of such microorganisms. Therefore, the ideal bio-based furan polyester packaging / spinning material needs to have both high barrier property and active antibacterial function.

[0003] The current mainstream technology gives the material antibacterial property by adding nano zinc oxide, nano silver oxide and other antibacterial agents, but this method has serious defects: (1) poor processing compatibility, and nano particles are easy to agglomerate, which leads to structural defects of the material and affects the mechanical properties; (2) high migration risk: the antibacterial agent migrates to the food during long-term use, which not only reduces the antibacterial durability, but also pollutes the taste of the food and causes safety hazards.

[0004] There are also attempts in the prior art to impart antibacterial properties to materials using organic antibacterial agents. Commonly used organic antibacterial agents include quaternary ammonium (phosphonium) compounds, pyridine compounds, guanidine compounds, halogenated amine compounds, and imidazole compounds. Thiazole derivatives exhibit broad-spectrum antibiotic activity against a variety of bacteria, including drug-resistant strains, and are particularly effective against gram-negative bacteria. In some cases, they are even superior to imidazole-based compounds. However, there are technical difficulties in this technology, which have prevented the successful implementation of organic antibacterial agents (such as (trifluoromethyl)thiazole-5-carboxylic acid derivatives) connected to polyester molecular chains, and the expected safe and high-performance antibacterial effect has not been achieved. The main technical difficulties are as follows: (1) Due to the electronic interaction of the groups, the reactivity of the organic antibacterial agent is reduced, making the copolymerized product unable to have antibacterial properties or having very low antibacterial properties, which prevents the expected antibacterial packaging material from achieving the desired effect. (2) Even if the organic antibacterial agent can be successfully combined with the food packaging material, there are still problems of uneven dispersion and poor compatibility, which prevent the expected antibacterial packaging material from achieving the desired effect. The reason is that the furan polyester main chain contains polar ester groups (-COO-), which makes the furan polyester as a whole exhibit moderate polarity and hydrophilicity. The thiazole ring is a five-membered heterocycle containing sulfur and nitrogen, which is electron-rich, but the polarity of the entire molecule is affected by the trifluoromethyl substituent, and the electron cloud is tightly pulled towards the fluorine atom, making -CF3 a strong electron-withdrawing group and a group with extremely low surface energy. This causes the entire molecule to exhibit extremely strong hydrophobicity (hydrophobicity) and low polarity. The large difference between the moderate polarity of furan polyester and the ultra-high hydrophobicity / low polarity of (trifluoromethyl)thiazole derivatives leads to thermodynamic incompatibility. During melt blending (such as twin-screw extrusion), thiazole derivatives tend to aggregate (self-assemble) themselves into micrometer or even nanometer-sized particles, rather than being dispersed in the polyester matrix as individual molecules.

[0005] Therefore, we designed a new type of antibacterial fully bio-based furan polyester and its preparation method using (trifluoromethyl)thiazole-5-carboxylic acid derivatives to solve the above problems. SUMMARY

[0006] In view of the defects in the prior art, the purpose of the present application is to design and provide a durable antibacterial fully bio-based furan polyester and its preparation method and application. The preparation method provided by the present application is green and environmentally friendly, and the fully bio-based furan polyester has a long-lasting and efficient antibacterial effect. It can still maintain extremely high antibacterial properties under long-term high temperature and high humidity conditions, and also has good yellowing resistance.

[0007] The present application successfully copolymerizes (trifluoromethyl) thiazole-5-carboxylic acid derivatives onto bio-based furan polyester, overcomes the following key technical difficulties, and realizes the innovative synthesis of functional furan polyester: (1) The strong electron-withdrawing property of the-CF3 group significantly reduces the reactivity of the 5-position carboxyl derivative of the thiazole ring. The present application overcomes the electronic and spatial obstacles of-CF3 through a special catalyst system, ensuring efficient attachment of the 5-carboxylic acid derivative to the bio-based furan polyester molecular chain. (2) The problem of poor dispersibility and low compatibility of (trifluoromethyl) thiazole-5-carboxylic acid derivatives in the bio-based furan polyester system is solved. The present application introduces flexible monomers (such as bio-based 1,4-butanediol, bio-based 1,3-butanediol, etc.) into the main chain of bio-based furan polyester through molecular chain structure design, alleviating the repulsion between rigid groups and the main chain, and promoting the uniform dispersion of functional groups in the bio-based furan polyester system.

[0008] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0009] On the one hand, the present application provides a preparation method of durable antibacterial full bio-based furan polyester, comprising the following steps:

[0010] (1) Weigh furan dicarboxylic acid monomer, bio-based diol monomer, stabilizer, water, antioxidant and catalyst, mix, and carry out esterification reaction under nitrogen or inert gas atmosphere. When the esterification rate reaches 90-97%, the esterification reaction is completed, and bio-based furan polyester esterification product is obtained.

[0011] (2) The obtained bio-based furan polyester esterification product is subjected to polycondensation reaction or curing reaction to obtain bio-based furan polyester. The viscosity of the obtained bio-based furan polyester is about 0.50-0.65 dL / g.

[0012] (3) Take the obtained bio-based furan polyester and monocarboxyl (trifluoromethyl) thiazole-5-carboxylic acid derivative, mix, and carry out polycondensation reaction under nitrogen atmosphere. The monocarboxyl derivative is copolymerized to the end of the bio-based furan polyester macromolecular chain as an end-capping agent and a molecular weight regulator to obtain antibacterial full bio-based furan polyester. The monocarboxyl derivative participates in esterification reaction through its monofunctional characteristics, permanently terminates molecular chain growth to realize end-capping, and realizes molecular weight regulation through the quantitative relationship between its feeding amount and final molecular weight.

[0013] The preparation method of the durable antibacterial full bio-based furan polyester, the furan dicarboxylic acid monomer is furan dicarboxylic acid;

[0014] The bio-based dihydric alcohol monomer is at least one of bio-based 1,3-propanediol, bio-based 1,2-propanediol, bio-based ethylene glycol, bio-based 1,4-butanediol, bio-based 1,3-butanediol, bio-based 2,2-dimethyl-1,3-propanediol, bio-based 1,5-pentanediol, bio-based polyether polyol, or bio-based tetrahydrofuran-2,5-dimethyl alcohol.

[0015] The molar ratio of the furandicarboxylic acid to the bio-based dihydric alcohol monomer is 1: (1-2.1).

[0016] The stabilizer is at least one of phosphoric acid, phosphorous acid, hypophosphorous acid, trimethyl phosphate, dimethyl phosphate, triphenyl phosphate, or diphenyl phosphate.

[0017] The mass of the stabilizer accounts for 5-100 ppm of the mass of the bio-based furan polyester.

[0018] The antioxidant is at least one of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, tris(2,4-di-tert-butylphenyl)phosphite, or bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite.

[0019] The mass of the antioxidant accounts for 15-300 ppm of the mass of the bio-based furan polyester.

[0020] The catalyst is at least one of antimony trioxide, ethylene glycol antimony, germanium oxide, titanium isopropoxide, or tetrabutyl titanate.

[0021] The mass of the catalyst accounts for 15-300 ppm of the mass of the bio-based furan polyester.

[0022] The mass of the water in step (1) accounts for 5-50% of the total mass of the furandicarboxylic acid and the bio-based dihydric alcohol monomer.

[0023] The esterification reaction is performed under a pressure of 0.1-0.3 MPa and a temperature of 170-210°C.

[0024] The polycondensation reaction in step (2) is performed under a controlled pressure of 50-200 pa, a temperature of 180-240°C, and a time of 90-240 min. 200 min.

[0025] The method for preparing a durable antibacterial fully bio-based furan polyester, wherein the mass of the monocarboxyl (trifluoromethyl)thiazole-5-carboxylic acid derivative comonomer in step (3) is 0.5-3% of the total mass of furan dicarboxylic acid and bio-based diol monomer;

[0026] The conditions for the polycondensation reaction in step (3) are: temperature 200-250℃, time 0.5-2h.

[0027] The method for preparing a durable antibacterial fully bio-based furan polyester, wherein the structural formula of the monocarboxyl (trifluoromethyl)thiazole-5-carboxylic acid derivative is shown in formula (Ⅰ) below:

[0028] Equation (I);

[0029] In the formula, R is , , , , ,

[0030] , , , , Any of the structures in it.

[0031] Secondly, the present invention provides a durable antibacterial fully bio-based furan polyester, obtained by any of the preparation methods described herein.

[0032] Thirdly, the present invention provides the application of the aforementioned durable antibacterial fully bio-based furan polyester as a durable antibacterial, high-barrier packaging material.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The raw materials of the fully bio-based furan polyester resin prepared by this invention are all derived from bio-based sources, making it green, environmentally friendly, and sustainable.

[0035] 2. The preparation method of this invention involves directly chemically bonding reactive antibacterial adjuvants to the fully bio-based furan polyester molecular chain, avoiding the reduction in antibacterial effect due to precipitation after long-term use and the complexity of material formulation due to the addition of compatibility adjuvants. The antibacterial effect is long-lasting and efficient, solving the problems of yellowing, poor compatibility, and uneven dispersion between traditional additive antibacterial adjuvants and furan polyester bulk material.

[0036] 3. The durable antibacterial fully bio-based furan polyester of this invention also has good anti-yellowing properties and can maintain extremely high antibacterial properties under long-term high temperature and high humidity conditions. Attached Figure Description

[0037] Figure 1 The image shows the antibacterial effect of the antibacterial furan polyester prepared in Example 1 against Escherichia coli.

[0038] Figure 2 The image shows the antibacterial effect of the antibacterial furan polyester prepared in Example 2 against Escherichia coli.

[0039] Figure 3 The image shows the antibacterial effect of the antibacterial furan polyester prepared in Example 3 against Escherichia coli.

[0040] Figure 4 The antibacterial effect of the antibacterial furan polyester prepared in Comparative Example 1 on Escherichia coli is shown in the figure.

[0041] Figure 5 SEM images of the antibacterial furan polyester prepared in Example 3 and Comparative Example 3, and the fully bio-based furan polyester prepared in Comparative Example 1, respectively. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to specific embodiments.

[0043] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the solution of the present invention are shown in the specific embodiments, while other details that are not closely related to the present invention are omitted.

[0044] Additionally, it should be noted that 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.

[0045] Example 1:

[0046] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0047] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1100 g of bio-based ethylene glycol, 0.19 g of germanium oxide, 0.3 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.2 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 200 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0048] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~120 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0049] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 17.5 g of 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 250℃ for polycondensation reaction for 30~100 minutes, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 10 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0050] Example 2:

[0051] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0052] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1000 g of bio-based ethylene glycol, 0.15 g of germanium oxide, 0.35 g of antimony trioxide, 0.45 g of triphenyl phosphate, 0.3 g of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 500 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.2-0.3 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 96%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0053] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~120 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0054] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 35.2 g of 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 245℃ for polycondensation reaction for 40~100 minutes, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 15 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0055] Example 3:

[0056] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0057] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1150 g of bio-based ethylene glycol, 3 g of bio-based 1,4-butanediol, 0.1 g of germanium oxide, 0.4 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.25 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 600 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0058] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~150 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0059] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 52.8 g of 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 250℃ and carry out polycondensation reaction for 30~100 minutes, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 20 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0060] Example 4:

[0061] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0062] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1100 g of bio-based ethylene glycol, 0.19 g of germanium oxide, 0.3 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.2 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 200 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0063] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~120 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0064] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 17.6g of 2-methoxy-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50Pa for about 1 hour, raise the temperature of the kettle to 250℃ for polycondensation reaction for 30~100 minutes, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 10 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0065] Example 5:

[0066] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0067] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1000 g of bio-based ethylene glycol, 0.15 g of germanium oxide, 0.35 g of antimony trioxide, 0.45 g of triphenyl phosphate, 0.3 g of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 500 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.2-0.3 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 96%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0068] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~120 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0069] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 35.4 g of 2-methoxy-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 245℃ for polycondensation reaction for 40~100 minutes, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 15 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0070] Example 6:

[0071] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0072] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1150 g of bio-based ethylene glycol, 0.1 g of germanium oxide, 0.4 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.25 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 600 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0073] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~150 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0074] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 min, add 53.1 g of 2-methoxy-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 250℃ for polycondensation reaction for 30~100 min, stop the reaction when the stirring power rises to 75 Hz, introduce nitrogen to atmospheric pressure, let stand for 20 min, stretch the strip through the water tank and then cut into pellets to obtain the fully bio-based antibacterial furan polyester.

[0075] Example 7:

[0076] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0077] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1200 g of bio-based 1,5-pentanediol, 0.2 g of germanium oxide, 0.3 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.25 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 500 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0078] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~120 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0079] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 17.5 g of 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 250℃ and carry out polycondensation reaction for 30~100 minutes. Stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 15 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0080] Example 8:

[0081] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0082] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1150 g of bio-based 1,5-pentanediol, 0.15 g of germanium oxide, 0.35 g of antimony trioxide, 0.45 g of triphenyl phosphate, 0.35 g of 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 600 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.2-0.3 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 96%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0083] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~120 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0084] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 35.2 g of 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 245℃ for polycondensation reaction for 40~100 minutes, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 15 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0085] Example 9:

[0086] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0087] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1250 g of bio-based 1,5-pentanediol, 0.1 g of germanium oxide, 0.4 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.25 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 600 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0088] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~150 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0089] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 minutes, add 52.8 g of 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 250℃ and carry out polycondensation reaction for 30~100 minutes, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 20 minutes, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0090] Example 10:

[0091] A method for preparing a fully bio-based antibacterial furan polyester specifically includes the following steps:

[0092] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1250 g of bio-based 1,5-pentanediol, 0.1 g of germanium oxide, 0.4 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.25 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 600 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0093] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~150 min, and stop stirring and turn off the vacuum pump when the stirring power rises to 65Hz.

[0094] (3) Introduce nitrogen to atmospheric pressure, let stand for 5 min, add 53.1 g of 2-methoxy-4-(trifluoromethyl)thiazole-5-carboxylic acid, turn on the vacuum pump, control the vacuum to below 50 Pa for about 1 hour, raise the temperature of the kettle to 250℃ for polycondensation reaction for 30~100 min, stop the reaction when the stirring power rises to 75Hz, introduce nitrogen to atmospheric pressure, let stand for 20 min, stretch the strip through the water tank and then cut it into pellets to obtain the fully bio-based antibacterial furan polyester.

[0095] Comparative Example 1:

[0096] The air in a 5L polyester reactor was replaced three times with high-purity nitrogen. Then, 1500 g of 2,5-furandicarboxylic acid, 1100 g of bio-based ethylene glycol, 0.19 g of germanium oxide, 0.3 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.2 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 200 g of water were added to the reactor. The pressure inside the reactor was controlled at 0.1–0.2 MPa, and the temperature was controlled at 170–200 °C. The esterification reaction ended when the esterification rate reached 95%, yielding the bio-based furan polyester ester.

[0097] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~200 min, stop stirring and turn off the vacuum pump when the stirring power rises to 75Hz, introduce nitrogen to normal pressure, let stand for 10 min, stretch into strips through a water tank and then granulate to obtain the fully bio-based furan polyester.

[0098] Comparative Example 2:

[0099] (1) High-purity nitrogen gas was introduced into a 5L polyester reactor to replace the air three times. 1500 g of 2,5-furandicarboxylic acid, 1200 g of bio-based 1,5-pentanediol, 0.2 g of germanium oxide, 0.3 g of antimony trioxide, 0.4 g of trimethyl phosphate, 0.25 g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 500 g of water were added to the reactor. The pressure inside the polymerization reactor was controlled at 0.1-0.2 MPa, and the temperature inside the polymerization reactor was controlled at 170-200℃. When the esterification rate reached 95%, the esterification reaction ended, and bio-based furan polyester esters were obtained.

[0100] (2) Turn on the vacuum pump, raise the reactor temperature to 210°C, control the vacuum to below 80Pa for about 1 hour, and then raise the reactor temperature to 230°C to carry out the polycondensation reaction. Polycondense for 90~120 min, stop stirring and turn off the vacuum pump when the stirring power rises to 75Hz, introduce nitrogen to normal pressure, let stand for 15 min, stretch into strips through a water tank and then granulate to obtain the fully bio-based furan polyester.

[0101] Performance testing should be conducted using appropriate standard methods.

[0102] First, the fully bio-based antibacterial furan polyester obtained in Examples 1-10 above, and the fully bio-based polyester obtained in Comparative Examples 1 and 2, are pressed into sheets using a flat vulcanizing machine to obtain sheets of 150×150×0.3mm. Then, the sheets are cut into strips of 25×150×0.3mm and square sheets of 40×40mm for later use.

[0103] 1. Mechanical performance testing

[0104] The test was conducted according to the national standard GB / T 1040.3, Determination of Tensile Properties of Plastics Part 3: Test Conditions for Films and Sheets, with a tensile rate of 50 mm / min and a gauge length of 50 mm. The results are shown in Table 1 below.

[0105] Table 1. Mechanical property test data of different antibacterial films or fully bio-based polyester films.

[0106]

[0107] 2. Antibacterial performance test

[0108] The antibacterial properties of plastic surfaces were tested according to the national standard GB / T 31402-2015, using the plate culture method to determine the number of viable bacteria for comparison. The bacteria tested were *Escherichia coli* and *Staphylococcus aureus*. The number of viable bacteria was calculated according to Formula 1 below:

[0109] N = (100 × C × D × V) / A; (Formula 1)

[0110] In Formula 1: N is the number of viable bacteria per square centimeter for each sample; C is the average colony count between the two culture dishes; D is the dilution factor; V is the volume used to elute the SCDLP culture medium, in mL; and A is the surface area of ​​the covering membrane, in cm². 2 .

[0111] The antibacterial properties are calculated using the following formula 2:

[0112] R=(Ut-U0)-(At-U0)=Ut-At; (Formula 2)

[0113] In Formula 2: R is the antibacterial performance value; U0 is the logarithmic mean of the number of bacteria immediately after inoculation of the untreated sample, expressed in CFU / cm². 2 Ut represents the logarithmic mean of bacterial count 24 hours after inoculation of the untreated sample, expressed in CFU / cm². 2 At represents the logarithmic mean of bacterial count 24 hours after inoculation of the antibacterial treated sample, expressed in CFU / cm².2 ).

[0114] The antibacterial performance data of the products prepared in Examples 1-10 and Comparative Examples 1-3 are shown in Table 2 below. The antibacterial effects of the antibacterial furan polyesters prepared in Examples 1-3 and the furan polyester prepared in Comparative Example 1 against *Escherichia coli* and *Staphylococcus aureus* are shown in the following graphs. Figures 1-4 As shown, the antibacterial furan polyester of the present invention has good antibacterial properties.

[0115] Table 2 Antibacterial performance data of different products

[0116]

[0117] Comparative Example 3:

[0118] PEF was synthesized using the same formulation as Comparative Example 1. Commercially available antibacterial powder was added to the PEF at a mass ratio of 1:99 (antibacterial powder:PEF). The mixture was then processed into antibacterial PEF slices using a twin-screw extruder.

[0119] Comparative Example 3 and Comparative Example 1 Figure 1 The membrane surfaces of the products (referred to as blank control example) and Comparative Example 3 were subjected to SEM microscopic image detection, and the results are as follows: Figure 5 As shown, after introducing the (trifluoromethyl)thiazole-5-carboxylic acid derivative into the bio-based furan polyester, the surface morphology of the resulting product was similar to that of the unmodified furan polyester, both exhibiting a smooth and flat characteristic, with no obvious phase separation or agglomeration. This indicates that the (trifluoromethyl)thiazole-5-carboxylic acid derivative of the present invention achieves good dispersibility and interfacial compatibility in the bio-based furan polyester matrix. In contrast, obvious phase separation and agglomeration were observed in Comparative Example 3, indicating poor compatibility.

[0120] The performance of the fully bio-based antibacterial furan polyester product obtained in Example 1 and the antibacterial PEF chips of Comparative Example 3 were compared and tested. The results are shown in Table 3 below.

[0121] Durable antibacterial testing methods:

[0122] Referring to ISO 105-C10-2006 "Tests for color fastness of textiles", 4.0 g of detergent was added to a beaker containing 1000 mL of deionized water, and the mixture was gently stirred with a glass rod until the detergent was completely dissolved in the deionized water. The flakes prepared for Example 1 and Comparative Example 3, along with three 10 mm diameter stainless steel balls, were added to separate beakers, which were placed in a constant-temperature water bath equipped with a stirrer. The stirrer simulated the mechanical action of washing, with each washing cycle lasting 10 minutes. After 30 washing cycles, the changes in antibacterial properties and mechanical properties of the flakes prepared for Example 1 and Comparative Example 3 were tested using the methods described above. The test results are shown in Tables 3 and 4 below.

[0123] Table 3. Antibacterial performance data of samples from Example 1 and Comparative Example 3 after 30 washing cycles.

[0124]

[0125] Table 4. Mechanical property test data of samples from Example 1 and Comparative Example 3 after 30 washing cycles.

[0126]

[0127] In summary, this invention overcomes the shortcomings of existing antibacterial PEF chips (such as the product obtained in Comparative Example 3), such as poor compatibility, a sharp decline in antibacterial performance, and a decrease in elongation at break and tensile strength after prolonged use, by polycondensing an antibacterial component with a unique structure, monocarboxylated (trifluoromethyl)thiazole-5-carboxylic acid derivative, with bio-based furan polyester. The product prepared by this invention provides long-lasting and durable antibacterial protection while maintaining excellent average tensile strength and elongation at break.

[0128] The above are merely preferred embodiments of the present invention, which will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that for those skilled in the art, any modifications and improvements made without departing from the concept of the present invention are protected by the present invention.

Claims

1. A method for preparing a durable antibacterial, fully bio-based furan polyester, characterized in that, Includes the following steps: (1) Weigh furan dicarboxylic acid monomer, bio-based diol monomer, stabilizer, water, antioxidant and catalyst, mix them, and carry out esterification reaction under nitrogen or inert gas atmosphere to obtain bio-based furan polyester ester. (2) Take the above-obtained bio-based furan polyester ester and carry out a polycondensation reaction or a curing reaction to obtain a bio-based furan polyester; (3) Take the above-obtained bio-based furan polyester and the monocarboxyl (trifluoromethyl)thiazole-5-carboxylic acid derivative, mix them, and carry out a polycondensation reaction under a nitrogen atmosphere to obtain an antibacterial fully bio-based furan polyester. The structural formula of the monocarboxyl (trifluoromethyl)thiazole-5-carboxylic acid derivative is shown in formula (Ⅰ): Equation (I); In the formula, R is , , , , , , , , , Any of the structures in it.

2. The method for preparing a durable antibacterial fully bio-based furan polyester as described in claim 1, characterized in that, The furanyl dicarboxylic acid monomer is furanyl dicarboxylic acid; The bio-based diol monomer is at least one of the following: bio-based 1,3-propanediol, bio-based 1,2-propanediol, bio-based ethylene glycol, bio-based 1,4-butanediol, bio-based 1,3-butanediol, bio-based 2,2-dimethyl-1,3-propanediol, bio-based 1,5-pentanediol, bio-based polyether polyol, or bio-based tetrahydrofuran-2,5-diethanol. The molar ratio of furanyl dicarboxylic acid to bio-based diol monomer is 1:(1~2.1).

3. The method for preparing a durable antibacterial fully bio-based furan polyester as described in claim 1, characterized in that, The stabilizer is at least one of phosphoric acid, phosphorous acid, hypophosphite, trimethyl phosphate, dimethyl phosphate, triphenyl phosphate, or diphenyl phosphate. The stabilizer accounts for 5 to 100 ppm of the bio-based furan polyester by mass.

4. The method for preparing a durable antibacterial fully bio-based furan polyester as described in claim 1, characterized in that, The antioxidant is at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, tris(2,4-di-tert-butylphenyl) phosphite, or bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite; The antioxidant is present in an amount of 15 to 300 ppm of the bio-based furan polyester.

5. The method for preparing a durable antibacterial fully bio-based furan polyester as described in claim 1, characterized in that, The catalyst is at least one of antimony trioxide, antimony glycolate, germanium oxide, titanium isopropoxide, or tetrabutyl titanate. The catalyst comprises 15 to 300 ppm of the bio-based furan polyester by mass.

6. The method for preparing a durable antibacterial fully bio-based furan polyester as described in claim 1, characterized in that, The mass of water mentioned in step (1) is 5-50% of the total mass of furanyl dicarboxylic acid and bio-based diol monomer; The conditions for the esterification reaction are: pressure 0.1-0.3 MPa, temperature 170-210℃; The conditions for the polycondensation reaction in step (2) are: pressure of 50-200 Pa, temperature of 180-240℃, and time of 90-200 min.

7. The method for preparing a durable antibacterial fully bio-based furan polyester as described in claim 1, characterized in that, The mass of the monocarboxyl (trifluoromethyl)thiazole-5-carboxylic acid derivative comonomer mentioned in step (3) is 0.5-3% of the total mass of furanyl dicarboxylic acid and bio-based diol monomer; The conditions for the polycondensation reaction in step (3) are: temperature 200-250℃, time 0.5-2h.

8. A durable, antibacterial, fully bio-based furan polyester, characterized in that, Obtained by the preparation method according to any one of claims 1-7.

9. The use of the durable antibacterial fully bio-based furan polyester as described in claim 8 as a durable antibacterial, high-barrier packaging material.

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