Polyurea functional material with stimulated fluorescent response and preparation method thereof

Abstract

The application belongs to the field of polymer preparation, and particularly relates to a preparation method of polyurea with a stimulating fluorescent response. H ), the fluorescent functional monomer (ON H ) is constructed by the reaction of epoxy resin and amino, and the phthalic acid group is suspended on the main chain by the reaction of ON and diisocyanate, so that the phthalic acid polymer is formed in the material, the structure or state of the phthalic acid polymer changes under different environments due to the different states of the carboxyl group under different pH values and the characteristic that the carboxyl group can form a coordination action with metal ions, the fluorescent characteristics change, and the fluorescent color changes from yellow-green to blue with the increase of the pH value. The preparation method of the polyurea with the stimulating fluorescent response is novel, the prepared polyurea has the stimulating fluorescent response characteristics, and has a wide market prospect. The steps are simple, the operation is convenient, and the practicability is high.

Description

Technical Field

[0001] This invention belongs to the field of polymer preparation, and particularly relates to a method for preparing fluorescent polyurea with stimuli response. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Fluorescent responsive materials are widely used in sensors, bioimaging, anti-counterfeiting labels, information encryption and flexible electronic devices because of their reversible or irreversible fluorescence changes caused by external stimuli (such as light, heat, pH, stress or specific chemicals).

[0004] Currently, by introducing fluorophores into the polyurea backbone or side chains via covalent bonds, or by combining them with the polyurea matrix through physical doping, it is possible to control the fluorescence intensity, wavelength, or lifetime of the material in response to specific external stimuli (such as mechanical stretching, pH changes, or the presence of metal ions). However, existing polyurea fluorescent responsive materials still have certain limitations in terms of stability and the controllability of the response mechanism.

[0005] A study prepared a fluorescent polyurea using NDI, polyetheramine, TEPA and IPDI as raw materials, but its fluorescence response is mainly reflected in the change of fluorescence intensity, which cannot be directly observed visually. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a fluorescently responsive polyurea and its preparation method. Through molecular structure design, phthalic acid groups are placed on the side chains to form a phthalic acid polymer. The structure of this polymer changes under different environments, resulting in altered fluorescence properties. This material is responsive to pH and Fe... 3+ Ions all have a certain response.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a polyurea functional material with a stimulated fluorescence response, having the following structural formula:

[0009]

[0010] Where n is a natural number greater than zero.

[0011] This invention constructs fluorescent functional monomers (ON) through the reaction of epoxy resin and amino groups. H ), via ON HThe reaction with diisocyanate causes phthalic acid groups to suspend on the main chain, forming phthalic acid polymers inside the material. Taking advantage of the different states of carboxyl groups under different pH conditions and their ability to coordinate with metal ions, the structure or state of phthalic acid polymers changes under different environments, and the fluorescence properties change accordingly. As the pH value increases, the fluorescence color changes from yellow-green to blue.

[0012] A second aspect of the present invention provides a method for preparing a polyurea functional material with a stimulated fluorescence response, comprising:

[0013] Ethylene glycol diglycidyl ether was reacted with 4-aminophthalic acid to generate a functional fluorescent small molecule ON. H ;

[0014] The functional fluorescent small molecule ON H Chain extension reaction with hexamethylene diisocyanate (HDI) produces a secondary amine-terminated prepolymer.

[0015] Hexamethylene diisocyanate (HDI) was prepolymerized with polyetheramine to generate an isocyanate-terminated prepolymer.

[0016] The secondary amine-terminated prepolymer is polymerized with an isocyanate-terminated prepolymer to obtain the final product.

[0017] A third aspect of the present invention provides a polyurea functional material with a stimulating fluorescence response prepared by the above-described method.

[0018] A fourth aspect of the present invention provides the application of the above-described polyurea functional material in the field of detection and information labeling.

[0019] Beneficial effects of the present invention

[0020] (1) The preparation method of fluorescent polyurea described in this invention is novel and the conditions are mild.

[0021] (2) This invention is based on weak intermolecular forces, forming phthalic acid polymers within the system, which can be used at different pH values ​​or Fe... 3+ Under certain conditions, the structure or state of phthalic acid polymers changes, altering the fluorescence properties of the material, primarily in terms of fluorescence intensity and color, which can be directly observed visually.

[0022] (3) The material described in this invention contains a large number of carboxyl groups, which can form a strong force with the surface of various substrates and have good adhesion properties.

[0023] (4) The preparation method of the present invention is simple, practical and easy to promote. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0025] Figure 1 Fluorescence spectra of materials prepared under different conditions and with different raw materials.

[0026] Figure 2 The graph shows the fluorescence changes of polyurea material after treatment with different pH values ​​and ionic solutions.

[0027] Figure 3 Adhesion force diagrams of materials prepared under different conditions and with different raw materials. Detailed Implementation

[0028] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods in the art or product instructions. Similarly, unless otherwise specified, the test methods of this invention are performed in accordance with conventional methods in the art or industry-standard methods or practices. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0030] A polyurea functional material with a stimulated fluorescence response has the following structural formula:

[0031]

[0032] Where n is a natural number greater than zero.

[0033] In some embodiments, the main aggregate structure is as follows (2HH consists of two phthalic acid groups forming hydrogen bonds, and 3HH and 3HHH consist of three phthalic acid groups forming hydrogen bonds in different states):

[0034]

[0035] This invention also provides a method for preparing a polyurea functional material with a stimulated fluorescence response, comprising:

[0036] Ethylene glycol diglycidyl ether was reacted with 4-aminophthalic acid to generate a functional fluorescent small molecule ON.H ;

[0037] The functional fluorescent small molecule ON H Chain extension reaction with hexamethylene diisocyanate (HDI) produces a secondary amine-terminated prepolymer.

[0038] Hexamethylene diisocyanate (HDI) was prepolymerized with polyetheramine to generate an isocyanate-terminated prepolymer.

[0039] The secondary amine-terminated prepolymer is polymerized with an isocyanate-terminated prepolymer to obtain the final product.

[0040] In some embodiments, the molar ratio of ethylene glycol diglycidyl ether to 4-aminophthalic acid is 1:1 to 1.1;

[0041] In some embodiments, the reaction temperature of the ethylene glycol diglycidyl ether with 4-aminophthalic acid is 30–80°C.

[0042] In some implementations, the ON H The molar ratio with HDI is 1:0.2 to 0.9;

[0043] In some embodiments, the chain extension reaction is carried out at a temperature of 60–100°C.

[0044] In some embodiments, the molar ratio of HDI to polyetheramine is 1:0.2 to 0.9;

[0045] In some embodiments, the prepolymerization reaction temperature is 60–100°C.

[0046] In some embodiments, the ratio of the secondary amine-terminated prepolymer to the isocyanate-terminated prepolymer is 1:1 to 1.1.

[0047] In some embodiments, the polymerization reaction is carried out at a temperature of 60–100°C.

[0048] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0049] In the following embodiments and comparative examples, the following test methods were used:

[0050] The pull-out test was conducted according to the national standard GB / T 5210-2006, at a test speed of 20 mm / min, at room temperature.

[0051] Fluorescence spectra were all measured under standardized conditions.

[0052] Example 1:

[0053] Weigh 2.71 g of ethylene glycol diglycidyl ether into a 150 ml round-bottom flask, add 4 ml of DMAC for dilution, and then add 3.74 g of 4-aminophthalic acid dispersed in 20 ml of DMAC to the round-bottom flask. Stir and react at 45 °C for 7 h to obtain the product ON. H Dry in an oven for later use. Weigh 6.45g ON H In a round-bottom flask, 20 ml of DMAC was used to dissolve and dilute the solution, and 8 mmol of hexamethylene diisocyanate was added. The reaction was carried out at 65 °C for 12 h. 0.842 g of N,N-di-tert-butylethylenediamine was weighed into a 150 ml round-bottom flask, diluted with 4 ml of DMAC, and 7 mmol of hexamethylene diisocyanate was added. The reaction was carried out at 65 °C for 3 h. After the reaction was complete, the two liquids were mixed and reacted for another 24 h to obtain a concentrated liquid. The resulting liquid was poured into a mold and dried in a vacuum oven at 80 °C for 48 h, then transferred to a forced-air oven at 80 °C for 48 h to obtain the sample FNHSPUA. All reactions were carried out under a nitrogen atmosphere.

[0054] Example 2:

[0055] Weigh 6.45g ON H In a round-bottom flask, 20 ml of DMAC was used to dissolve and dilute the polyetheramine D-2000, and 8 mmol of hexamethylene diisocyanate was added. The mixture was reacted at 65°C for 12 h. 10 g of polyetheramine D-2000 was weighed into a 150 ml round-bottom flask, diluted with 4 ml of DMAC, and 7 mmol of hexamethylene diisocyanate was added. The mixture was reacted at 65°C for 3 h. After the reaction was complete, the two liquids were mixed and reacted for another 24 h to obtain a thick liquid. The resulting liquid was poured into a mold and dried in a vacuum oven at 80°C for 48 h, then transferred to a forced-air oven at 80°C for another 48 h to obtain the sample FDHSPUA. All reactions were carried out under a nitrogen atmosphere.

[0056] Example 3:

[0057] Weigh 6.45g ON H In a round-bottom flask, 20 ml of DMAC was used to dissolve and dilute the solution, and 8 mmol of hexamethylene diisocyanate was added. The reaction was carried out at 65 °C for 12 h. 0.431 g of N,N-di-tert-butylethylenediamine and 5 g of polyetheramine D-2000 were weighed into a 150 ml round-bottom flask, diluted with 4 ml of DMAC, and 7 mmol of hexamethylene diisocyanate was added. The reaction was carried out at 65 °C for 3 h. After the reaction was complete, the two liquids were mixed and reacted for another 24 h to obtain a thick liquid. The resulting liquid was poured into a mold and dried in a vacuum oven at 80 °C for 48 h, then transferred to a forced-air oven at 80 °C for 48 h to obtain the sample FNDHSPUA. All reactions were carried out under a nitrogen atmosphere.

[0058] Comparative Example 1:

[0059] Weigh 6.45g ON H 0.842 g of N,N-di-tert-butylethylenediamine was placed in a 150 ml round-bottom flask, dissolved and diluted with 20 ml of DMAC, and then 15 mmol of hexamethylene diisocyanate was added. The mixture was reacted at 65 °C for 48 h. The liquid was poured into a mold and dried in a vacuum oven at 80 °C for 48 h, and then transferred to a forced-air oven at 80 °C for 48 h to obtain the sample YNHSPUA.

[0060] Comparative Example 2:

[0061] Weigh 6.45g ON H 10g of polyetheramine D-2000 was placed in a 150ml round-bottom flask, dissolved and diluted with 20ml of DMAC, and then 15mmol of hexamethylene diisocyanate was added. The mixture was reacted at 65℃ for 48h. The liquid was poured into a mold and dried in a vacuum oven at 80℃ for 48h. Then it was dried in a forced-air oven at 80℃ for 48h to obtain sample YDHSPUA.

[0062] Comparative Example 3

[0063] The difference from Example 3 is that 10 mmol of N,N-di-tert-butylethylenediamine was used to replace ON. H The remaining reaction process was the same as in Example 3, yielding sample NDSPUA.

[0064] Table 1 shows a comparison of the mechanical properties of different embodiments and comparative examples, demonstrating that the fluorescent polyurea synthesized in this invention has excellent adhesion.

[0065] Table 1

[0066]

[0067] like Figure 1As shown, FNDHSPUA was treated with different solutions (immersed in different solutions for 30 minutes and then removed), and its fluorescence was tested (the actual fluorescence color change was obtained under UV light). With increasing pH, the material's fluorescence changed from the original yellow-green to yellow and finally to blue. Under alkaline conditions, sodium hydroxide reacts with phthalic acid groups, gradually transforming the original carboxyl groups into sodium carboxylate, altering the structure of the original fluorescent center and leading to a significant change in fluorescence characteristics. With increasing sodium hydroxide concentration, the amount of carboxyl groups reacting with sodium hydroxide in the system increases within the same time frame, and the yellow-green fluorescence dominated by phthalic acid polymers gradually changes to blue fluorescence. When in contact with strong acids, the tertiary amines in the system undergo protonation, readily forming hydrogen bonds with phthalic acid, thus altering the fluorescent active center and changing the material's fluorescence characteristics. Upon encountering iron ions (saturated ferric chloride solution), the fluorescence is quenched. NDSPUA lacking phthalic acid groups exhibits very weak fluorescence and no significant pH response.

[0068] like Figure 2 As shown, the fluorescence intensity of FNDHSPUA was measured after treatment with different solutions (fluorescence spectra were obtained by a fluorescence spectrometer with an excitation wavelength of 365 nm). It can be seen that the fluorescence intensity changed significantly. This is because different solution environments alter the structure or state of the phthalic acid polymer, thus changing its fluorescence intensity.

[0069] like Figure 3 As shown, FNDHSPUA exhibits the highest adhesion strength, exceeding that of epoxy resin (ergo.5210). The physical image reveals that the fracture was caused by the epoxy resin, indicating that the adhesion strength of FNDHSPUA is above 5.4 MPa. This material contains ordered hydrogen bonds, and the introduction of small-molecule diamines increases the hard segment content. H With relatively short distances between structures, phthalic acid groups are more likely to form polymers, providing strong connections for the internal structure of the material.

[0070] All of these fluorescent properties make this material applicable to fields such as detection and labeling.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a polyurea functional material with a stimulated fluorescence response, characterized in that, include: Ethylene glycol diglycidyl ether was reacted with 4-aminophthalic acid to generate a functional fluorescent small molecule ON. H ; The functional fluorescent small molecule ON H Chain extension reaction with hexamethylene diisocyanate (HDI) produces a secondary amine-terminated prepolymer. Hexamethylene diisocyanate (HDI) was prepolymerized with polyetheramine to generate an isocyanate-terminated prepolymer. The secondary amine-terminated prepolymer is polymerized with an isocyanate-terminated prepolymer to obtain the final product.

2. The method for preparing the polyurea functional material with stimulated fluorescence response as described in claim 1, characterized in that, The molar ratio of ethylene glycol diglycidyl ether to 4-aminophthalic acid is 1:1 to 1.1; Alternatively, the reaction temperature of the ethylene glycol diglycidyl ether with 4-aminophthalic acid is 30~80℃.

3. The method for preparing the polyurea functional material with stimulated fluorescence response as described in claim 1, characterized in that, During the preparation of the secondary amine-terminated prepolymer, ON H The molar ratio with HDI is 1:0.2~0.9; Alternatively, the chain extension reaction can be carried out at a temperature of 60-100°C.

4. The method for preparing the polyurea functional material with stimulated fluorescence response as described in claim 1, characterized in that, The molar ratio of HDI to polyetheramine in the preparation of the isocyanate-terminated prepolymer is 1:0.2~0.9; Alternatively, the temperature of the prepolymerization reaction is 60~100℃.

5. The method for preparing a polyurea functional material with a stimulating fluorescence response as described in claim 1, characterized in that, The ratio of the secondary amine-terminated prepolymer to the isocyanate-terminated prepolymer is 1:1 to 1.

1.

6. The method for preparing the polyurea functional material with stimulated fluorescence response as described in claim 1, characterized in that, The polymerization reaction is carried out at a temperature of 60~100℃.

7. The polyurea functional material with a stimulating fluorescence response prepared by the method according to any one of claims 1-6, characterized in that, The structure is as follows: ； Where n is a natural number greater than zero.

8. The application of the polyurea functional material according to claim 7 in the field of detection and information labeling.

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