Polyurethane material with fluorescent and antibacterial properties and preparation method thereof

Abstract

The present invention discloses a polyurethane material with fluorescent and antibacterial properties and a preparation method thereof. The present invention first prepares product 1 using paraformaldehyde and diethanolamine, then adds an antibacterial drug to product 1 to obtain product 2; then, polymer 1 is prepared using polyol, polyisocyanate, and product 2 as main raw materials; and finally, pyrene with a vinyl group is introduced to obtain the final product. The material has fluorescent and antibacterial properties; is made from naturally available compounds and has good biosafety; effectively reduces the flexibility of the polymer chain; while improving thermal stability, relies on the π-π effect to synergistically inhibit local fluorescence quenching by attracting pyrene; is less likely to agglomerate during the polymerization process, thus avoiding the problem of fluorescence quenching; and exhibits excellent physical and mechanical properties.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials and relates to a polyurethane material with fluorescence and antibacterial properties and a preparation method thereof. Background Art

[0002] Functional coatings have gained widespread consumer favor in recent years due to their unique functionality. By incorporating special properties such as fluorescence and antimicrobial properties into coatings, applied to surfaces, they not only form a stable, uniform film but also protect and beautify the material. Their unique functionality imbues ordinary polymeric materials with new vitality. Fluorescence, a rapidly developing functional coating, can be used in areas such as signage, anti-counterfeiting, and lighting. Protective clothing and gloves with antimicrobial coatings are among the most in-demand functional products in the market and pharmaceutical sectors.

[0003] Traditional polymer luminescent materials are prone to agglomeration when physically blended during polymerization, resulting in poor luminescence performance. Researchers have avoided agglomeration by physically blocking the polymerization process. After physical blocking, agglomeration during the reaction process can be effectively prevented. In traditional preparation methods, pyrene is prone to fluorescence quenching at high concentrations or in an aggregated state. Assuming that these aromatic units are connected to the polymer skeleton by chemical bonding methods, there is steric hindrance in the polymer main chain to form a sandwich polymer, which effectively prevents the aggregation of fluorescent components, so that the polymer can emit fluorescence well even in the aggregated state. However, even if there are related studies that use steric hindrance, there are still defects when it is actually applied to polymers. For example, when the flexibility of the polymer main chain is high, then during the movement of the chain segments or polymers, the easily quenched fluorescent polymer will still experience local quenching or a decrease in fluorescence intensity.

[0004] Furthermore, studies have shown that traditional antimicrobial materials, such as metals, face significant challenges in achieving their antimicrobial properties due to their high cost and, more importantly, toxicity. Similarly, while antibiotics kill bacteria and viruses, long-term use can lead to drug resistance. Small molecule antimicrobial materials, while addressing the shortcomings of these materials, can also lead to short-term antimicrobial effects. Our antimicrobial material, incorporated into our antimicrobial luminescent polymer, offers excellent antimicrobial properties, a simple extraction process, and low cost, effectively resolving these issues with traditional antimicrobial materials. Summary of the Invention

[0005] The purpose of the present invention is to develop a new functional polymer material with fluorescent and antibacterial properties in response to the problems existing in traditional antibacterial fluorescent materials. The polyurethane fluorescent antibacterial material provided by the present invention is made from naturally available compounds and has good biocompatibility. The antibacterial material provided by the present invention has better thermal stability and effectively reduces the flexibility of the polymer chain. While improving thermal stability, it relies on the π-π effect to attract pyrene to synergistically hinder local fluorescence quenching or intensity reduction. The fluorescent material provided by the present invention is not prone to agglomeration during the polymerization process, avoids the problem of fluorescence quenching, and has good physical and mechanical properties.

[0006] In order to solve the technical problem, the technical solution adopted by the present invention is:

[0007] A polyurethane material with fluorescent and antibacterial properties and a preparation method thereof, characterized by comprising the following steps:

[0008] (1) Preparation of Product 1:

[0009] Add 0.5-6 parts by weight of paraformaldehyde and 0.5-6 parts by weight of diethanolamine to a three-necked flask, then heat and stir the reactants at 50-80°C for 1-4.5 hours. Then, add 10-90 parts by weight of distilled water to the reactants to obtain Product 1.

[0010] (2) Preparation of Product 2:

[0011] 10-60 parts by weight of the product 1 obtained in step (1) is added with 1-9.5 parts by weight of an antibacterial drug, and the mixture is heated and stirred at 80-120° C. for 3-8.5 hours, and then cooled to room temperature to obtain product 2;

[0012] (3) Preparation of polymer:

[0013] 5-30 parts by weight of the product 2 prepared in step (2) are placed in a reactor, 10-40 parts by weight of a polyol and 30-75 parts by weight of a polyisocyanate are added, and the mixture is heated and stirred at 50-100° C. for 1.5-6 hours. 15-50 parts by weight of thioacetic acid are then added to the reactor, followed by 1-4 parts by weight of azobisisobutyronitrile. The mixture is heated and stirred for 0.5-3 hours, and then 10-60 parts by weight of a methanol or ethanol solution of potassium hydroxide (the mass ratio of potassium hydroxide is 10-20%, and the reaction needs to be carried out in a deoxygenated environment) is added. The reaction is continued for 0.5-1 hour and then cooled to room temperature to obtain a polymer 1. Take 10-20 parts by weight of polymer 1 and parts of vinyl-containing pyrene (preparation method refers to Chem. Mater. 2004, 16, 4005-4011), mix them evenly, then add 0.1-1.6 parts by weight of azobisisobutyronitrile, move them to a reactor with a condenser and 50-100 parts by weight of N,N-dimethylformamide, stir and react at 60-85°C for 50-100 hours, and after the reaction is completed, take the product and dry it as the final product.

[0014] Furthermore, the antibacterial drug in step (2) is eugenol.

[0015] Furthermore, the polyol in step (3) is selected from one of the following substances: polyethylene glycol with a molecular weight of 200-600, polypropylene glycol with a molecular weight of 400-2000, polyethylene adipate glycol with a molecular weight of 400-1500, and poly(neopentyl phthalate) polyester glycol with a molecular weight of 400-1500.

[0016] Furthermore, the polyisocyanate in step (3) is selected from one of the following substances: hexamethylene diisofluoride, cycloaliphatic diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

[0017] A polyurethane material with fluorescent and antibacterial properties prepared according to any of the above preparation methods.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The polyurethane fluorescent antibacterial material provided by the present invention is partially made of naturally available compounds and has good biosafety.

[0020] 2. Compared with traditional antibacterial materials, the present invention not only has excellent antibacterial effect, but also has better thermal stability.

[0021] 3. The fluorescent material provided by the present invention is not prone to agglomeration during the polymerization process, thus avoiding the problem of local fluorescence quenching and having good physical and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0023] Figure 1 This is the infrared spectrum of Example 3. DETAILED DESCRIPTION

[0024] The present invention is described in detail below by way of examples, which are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. It should be understood that after reading the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and such equivalent forms also fall within the scope defined by the claims appended hereto.

[0025] Example 1

[0026] (1) Preparation of Product 1:

[0027] 0.5 parts by weight of paraformaldehyde and 0.5 parts by weight of diethanolamine were added to a three-necked flask, and the reactants were heated and stirred at 50°C for 1 hour. 10 parts by weight of distilled water were then added to the reactants to obtain Product 1.

[0028] (2) Preparation of Product 2:

[0029] 10 parts by weight of the product 1 obtained in step (1) was added with 1 part by weight of eugenol, and the mixture was heated and stirred at 80° C. for 3 hours, and then cooled to room temperature to obtain product 2.

[0030] (3) Preparation of polymer:

[0031] 5 parts by weight of the product 2 obtained in step (2) were placed in a reactor, 10 parts by weight of polyethylene adipate glycol and 30 parts by weight of isophorone diisocyanate were added, and the mixture was heated and stirred at 50° C. for 1.5 hours. 15 parts by weight of thioacetic acid and 1 part by weight of azobisisobutyronitrile were added to the reactor, and the mixture was heated and stirred for 0.5 hours. 10 parts by weight of an ethanol solution of potassium hydroxide (potassium hydroxide accounted for 15% by weight) was then added, and the mixture was allowed to react for 0.5 hours before cooling to room temperature to obtain polymer 1. 10 parts by weight of polymer 1 and 2 parts by weight of vinyl-containing pyrene were mixed uniformly, and 0.1 parts by weight of azobisisobutyronitrile was added. The mixture was transferred to a reactor equipped with a condenser and charged with 50 parts by weight of N,N-dimethylformamide, and the mixture was stirred and reacted at 60° C. for 50 hours. After the reaction, the product was dried to obtain the final product.

[0032] Example 2

[0033] (1) Preparation of Product 1:

[0034] 3 parts by weight of paraformaldehyde and 3 parts by weight of diethanolamine were added to a three-necked flask, and the reactants were heated and stirred at 80°C for 1 hour. 20 parts by weight of distilled water were then added to the reactants to obtain Product 1.

[0035] (2) Preparation of Product 2:

[0036] 20 parts by weight of the product 1 obtained in step (1) were added to 2 parts by weight of eugenol, and the mixture was heated and stirred at 90° C. for 3 hours, and then cooled to room temperature to obtain product 2;

[0037] (3) Preparation of polymer:

[0038] 5 parts by weight of the product 2 obtained in step (2) were placed in a reactor, 20 parts by weight of polyethylene adipate glycol and 40 parts by weight of isophorone diisocyanate were added, and the mixture was heated and stirred at 60°C for 1.5 hours. 25 parts by weight of thioacetic acid and 2 parts by weight of azobisisobutyronitrile were added to the reactor, and the mixture was heated and stirred for 0.5 hours. 20 parts by weight of a methanol solution of potassium hydroxide (potassium hydroxide accounted for 10% by weight) were added, and the mixture was allowed to react for 0.5 hours before cooling to room temperature to obtain polymer 1. 15 parts by weight of polymer 1 and 5 parts by weight of vinyl-containing pyrene were mixed uniformly, and 1 part by weight of azobisisobutyronitrile was added. The mixture was transferred to a reactor equipped with a condenser and charged with 80 parts by weight of N,N-dimethylformamide, and the mixture was stirred and reacted at 60°C for 50 hours. After the reaction, the product was dried to obtain the final product.

[0039] Example 3

[0040] (1) Preparation of Product 1:

[0041] 2 parts by weight of paraformaldehyde and 2 parts by weight of diethanolamine were added to a three-necked flask, and the reactants were heated and stirred at 50°C for 1 hour. 20 parts by weight of distilled water were then added to the reactants to obtain Product 1.

[0042] (2) Preparation of Product 2:

[0043] 15 parts by weight of the product 1 obtained in step (1) was added with 2 parts by weight of eugenol, and the mixture was heated and stirred at 100° C. for 3 hours, and then cooled to room temperature to obtain product 2;

[0044] (3) Preparation of polymer:

[0045] 8 parts by weight of the product 2 obtained in step (2) were placed in a reactor, 20 parts by weight of polyethylene adipate glycol and 30 parts by weight of isophorone diisocyanate were added, and the mixture was heated and stirred at 50° C. for 2 hours. 30 parts by weight of thioacetic acid and 2 parts by weight of azobisisobutyronitrile were added to the reactor, and the mixture was heated and stirred for 1 hour. 20 parts by weight of an ethanol solution of potassium hydroxide (potassium hydroxide accounted for 15% by weight) was then added, and the reaction was continued for 0.5 hours before cooling to room temperature to obtain polymer 1. 15 parts by weight of polymer 1 and 3 parts by weight of vinyl-containing pyrene were mixed uniformly, and 0.3 parts by weight of azobisisobutyronitrile was added. The mixture was transferred to a reactor equipped with a condenser and charged with 50 parts by weight of N,N-dimethylformamide, and the mixture was stirred and reacted at 70° C. for 60 hours. After the reaction was completed, the product was dried to obtain the final product.

[0046] Control group 1

[0047] Physical blending of pure pyrene and polyurethane polymer (the ratio of pure pyrene to polyurethane polymer in Control Group 1 was set to the same ratio as that of pyrene in the polymer in Example 3, and the polyurethane was prepared by physical blending after being dissolved in a good solvent. However, Product 2 was not added during the preparation of the polyurethane, and the mass of Product 2 was replaced by the corresponding polyol in Example 3. The reaction steps refer to the specification (3) Polymer Synthesis)

[0048] Control group 2

[0049] A covalently bonded pyrene polymer without eugenol (the ratio of the pyrene composition of the control group 1 to the polyurethane polymer is set to the same ratio as that of the pyrene in the polymer in Example 3, but the polyurethane is prepared by replacing product 2 with the same mass of methyl succinate bis(2-hydroxypropyl)diol. The reaction steps refer to the polymer synthesis in the specification (3)).

[0050] Antibacterial testing:

[0051] Antibacterial testing was performed on each embodiment of the present invention. The measurement standard was based on the International Journal of Polymer Science Volume 2018, Article ID 5659137. Escherichia coli was selected and the bacterial count was reduced to 104 cfu / piece. The measurement results are shown in the following table.

[0052] Antibacterial rate (%) Example 1 ＞99.9 Example 2 ＞99.9 Example 3 ＞99.9 Control group 1 0 Control group 2 0

[0053] Table 1 Antibacterial test results

[0054] It can be found that the antibacterial effect is good. After the introduction of the eugenol component, Examples 1-3 all exhibit good antibacterial properties.

[0055] Infrared test reference http: / / dx.doi.org / 10.1080 / 09205063.2016.1181375, attached Figure 1 Display 1600cm -1 There is a peak belonging to the benzene ring at 1635cm, which is attributed to eugenol and pyrene groups. -1 The disappearance of the double bond peak at 1740 cm indicates that a click chemistry reaction has occurred. -1 Its characteristic peak. 1517cm -1 Nearby are the CN and NH peaks belonging to polyurethane, indicating that the polymer of Example 3 was successfully prepared.

[0056] Thermal stability:

[0057] Thermal stability was tested using a TA Instruments Q-50. Approximately 10 mg of sample was placed in a standard aluminum pan and heated from room temperature to 700°C at a heating rate of 10°C / min under a nitrogen flow of 50 cm³ / min. Thermogravimetric curves for five groups of samples (Examples 1-3 in the experimental group) and Controls 1 and 2 were measured. The initial thermal decomposition temperature and the residual mass of the five groups upon thermal decomposition at 280°C were compared to evaluate the impact of this experimental design on the thermal stability of the polymers.

[0058] Experimental results: Initial thermal decomposition temperature (mass loss 5wt%): Control group 1 is the lowest (225°C); Control group 2 is second (247°C); Examples 1-3 are all higher than Control group 1 and Control group 2, which are (308°C, 285°C, 322°C), respectively.

[0059] The residual mass when pyrolysis occurred at 280°C was: control group 1 (72.7%) < control group 2 (85.1%) < example 2 (94.3%) < example 1 (97.2%) < example 3 (97.6%).

[0060] Fluorescence:

[0061] The experimental group examples 1-3 and the control group 1 and the control group 2 were dissolved in tetrahydrofuran respectively (they can be directly coated without drying when prepared). After complete dissolution, the four groups of samples were evenly coated on a 20×20mm slide. Five groups of parallel controls were set for each sample, with a total of 25 samples. The thickness of the film applied to the slide of the five groups of samples was controlled to be the same (within 50-100μm). After film formation, an Olympus fluorescence microscope IX73 (40X objective lens) was used to observe whether there was an obvious dark area in the film. If one case appeared, it was classified as unqualified. The dispersion of pyrene in each embodiment and the control group was detected to evaluate the effect of this experimental design on pyrene agglomeration. The experimental results are shown in the following table:

[0062]

[0063] Table 2 Fluorescence microscopy results

[0064] It can be seen that Examples 1-3 were essentially unqualified, while both Control 1 and Control 2 showed dark areas. Although Control 2 showed fewer dark areas than Control 1, it was not completely devoid of them, and thus was classified as unqualified. This indicates that further limiting the mobility of the pyrene group can effectively reduce the probability of quenching.

[0065] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements, or modifications based on the present invention to solve substantially the same technical problems and achieve substantially the same technical effects are all included in the scope of protection of the present invention.

Claims

1. A method for preparing a polyurethane material with fluorescent and antibacterial properties, characterized in that: The steps include: (1) Preparation of Product 1: Add 0.5-6 parts by weight of paraformaldehyde and 0.5-6 parts by weight of diethanolamine to a three-necked flask, then continue heating and stirring the reactants at 50-80° C. for 1-4.5 hours, and then add 10-90 parts by weight of distilled water to the reactants to obtain product 1; (2) Preparation of Product 2: 10-60 parts by weight of the product 1 obtained in step (1) is added with 1-9.5 parts by weight of an antibacterial drug, and the mixture is heated and stirred at 80-120° C. for 3-8.5 hours, and then cooled to room temperature to obtain product 2; (3) Preparation of polymer: 5-30 parts by weight of the product 2 prepared in step (2) are placed in a reactor, 10-40 parts by weight of a polyol and 30-75 parts by weight of a polyisocyanate are added, and the mixture is heated and stirred at 50-100° C. for 1.5-6 hours. 15-50 parts by weight of thioacetic acid are then added to the reactor, followed by 1-4 parts by weight of azobisisobutyronitrile, and the mixture is heated and stirred for 0.5-3 hours. 10-60 parts by weight of a methanol or ethanol solution of potassium hydroxide are then added. The reaction is carried out in a deoxygenated environment, and the reaction is continued for 0.5-1 hour, followed by cooling to room temperature to obtain polymer 1; 10-20 parts by weight of polymer 1 and 2-10 parts of pyrene with a vinyl group are mixed uniformly, and then 0.1-1.6 parts by weight of azobisisobutyronitrile are added. The mixture is transferred to a reactor equipped with a condenser and containing 50-100 parts by weight of N,N-dimethylformamide, and stirred at 60-85° C. for 50-100 hours. After the reaction is completed, the product is dried to obtain the final product; The antibacterial drug in step (2) is eugenol; In the step (3), the mass ratio of potassium hydroxide is 10-20%.

2. The method for preparing a polyurethane material with fluorescent and antibacterial properties according to claim 1, characterized in that: The polyol in step (3) is selected from one of the following substances: polyethylene glycol with a molecular weight of 200-600, polypropylene glycol with a molecular weight of 400-2000, polyethylene adipate glycol with a molecular weight of 400-1500, and poly(neopentyl phthalate) polyester glycol with a molecular weight of 400-1500.

3. The method for preparing a polyurethane material with fluorescent and antibacterial properties according to claim 1, characterized in that: The polyisocyanate in step (3) is selected from one of the following substances: hexamethylene diisocyanate, cycloaliphatic diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

4. A polyurethane material with fluorescent and antibacterial properties obtained according to the preparation method according to any one of claims 1 to 3.

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