A branched fluorescent polymer and its preparation method

Abstract

This invention relates to the field of fluorescent polymer technology, specifically to a branched fluorescent polymer and its preparation method. The solid-state fluorescence quantum yield of linear fluorescent polymers obtained by reacting amino alcohol monomers with activated alkyne monomers is difficult to reach above 30%. Based on the above problem, this invention provides a branched fluorescent polymer. Through a click reaction between amino alcohol monomers and activated alkyne monomers, a series of branched fluorescent polymers are obtained. The solid-state fluorescence quantum yield of the obtained branched fluorescent polymers is significantly higher than that of linear fluorescent polymers, easily reaching levels above 30%.

Description

Technical Field

[0001] This invention relates to the field of fluorescent polymer technology, and more specifically to a branched fluorescent polymer and its preparation method. Background Technology

[0002] Over the past decade, non-conjugated fluorescent polymers, such as polyamides, polysiloxanes, polyureas, polyethers, and polyphosphates, have been discovered to exhibit unexpected luminescent properties under ultraviolet light excitation. Generally, the abundant electron-rich heteroatom groups (such as amides, C=O, C=N, etc.) in non-conjugated fluorescent polymers can form intramolecular or intermolecular dangling clusters, thereby triggering fluorescence emission. Unlike conjugated fluorescent polymers, non-conjugated fluorescent polymers typically do not produce strong fluorescence because the primary absorption is a result of n-π* excitation rather than π-π* excitation.

[0003] Non-conjugated fluorescent polymers constructed from branched polymers not only possess the advantages of abundant and usable polymerization end groups, but also exhibit tunable chemical structures and fluorescence, providing a feasible approach for designing non-conjugated fluorescent polymers with high fluorescence quantum yields. Therefore, the design of non-conjugated fluorescent polymers with high fluorescence quantum yields using efficient polymerization methods has significant practical value.

[0004] Click polymerization is a highly efficient method for polymer synthesis due to its advantages such as good selectivity, wide applicability, mild conditions, high efficiency, no byproducts, and atom economy. Researchers have now achieved high-yield production of nitrogen-containing polymers by click polymerization of nucleophilic amine monomers with unsaturated monomers (double or triple bonds) at room temperature under catalytic-free conditions. Hydroxyl monomers, like amino monomers, are also commonly used nucleophiles. Compared to amines, alcohol monomers have the advantages of being more diverse, widely available, stable, and non-toxic with no irritating odor. However, the polymerization of alcohol monomers with unsaturated monomers usually requires the addition of a catalyst.

[0005] Using click reactions, the research team of this invention has developed a variety of linear fluorescent polymer luminescent materials, but the solid-state fluorescence quantum yield of the obtained linear fluorescent polymers is difficult to reach more than 30%. Summary of the Invention

[0006] A problem with existing technologies is that the solid-state fluorescence quantum yield of linear fluorescent polymers obtained by reacting amino alcohol monomers with activated alkynyl monomers is difficult to reach above 30%. To address this problem, this invention provides a branched fluorescent polymer, which is generated by a click reaction between an amino alcohol monomer and an alkynyl monomer. During the reaction, the alkynyl group in the alkynyl monomer structure first undergoes a click reaction with the primary or secondary amino group in the amino alcohol monomer structure, and then undergoes a click reaction with the hydroxyl group in the primary or secondary amino alcohol monomer structure. The alkynyl monomer molecular chain is capped at both ends by two alkynyl groups. The amino alcohol monomer includes a primary amino alcohol monomer or a secondary amino alcohol monomer containing at least two hydroxyl groups.

[0007] Preferably, the alkynyl monomer includes a dialkynyl monomer or a polyalkynyl monomer whose molecular chain is capped by two alkynyl groups at both ends.

[0008] Preferably, the diacetyl monomer comprises the following structural formula:

[0009]

[0010] In the above structural formula, m is 1 to 3, and n>2.

[0011] Preferably, the polyacetylenic monomer comprises the following structural formula:

[0012]

[0013] Preferably, the primary amino alcohol monomer includes monohydroxy primary amino alcohol, dihydroxy primary amino alcohol, or polyhydroxy primary amino alcohol.

[0014] Preferably, the monohydroxy primary amino alcohol includes propanolamine or isopropanolamine.

[0015] Preferably, the dihydroxy primary amino alcohol includes diethanolamine, bis(2-hydroxypropyl)amine, or N,N'-bis(2-hydroxyethyl)ethylenediamine.

[0016] Preferably, the polyhydroxy primary amino alcohol comprises 1,3-bis[tris(hydroxymethyl)methylamino]propane.

[0017] Preferably, during the click reaction, the primary amino alcohol monomer is 1,3-bis[tris(hydroxymethyl)methylamino]propane, the alkynyl monomer is ethylene glycol dipropynate, and the molar ratio of the primary amino alcohol monomer to the alkynyl monomer is 1:2.

[0018] The present invention has the following beneficial effects:

[0019] (1) The present invention obtains a series of branched fluorescent polymers by clicking reaction of primary amine alcohol or secondary amine alcohol containing at least two hydroxyl groups with activated alkyne monomers. By optimizing the types of primary amine and secondary amine alcohol, the obtained branched fluorescent polymers all obtain high solid fluorescence quantum yields, all of which can reach more than 30%, and achieve good technical results.

[0020] (2) The method of the present invention has high atom utilization, good selectivity, and good yield. It does not require the use of any catalyst and can react in a temperature range of 0-60℃, which has good market prospects. Attached Figure Description

[0021] Figure 1 : This is the 1H NMR spectrum of the fluorescent polymer obtained in Example 1.

[0022] Figure 2 : This is the fluorescence spectrum of the fluorescent polymer obtained in Example 1.

[0023] Figure 3 : This is the 1H NMR spectrum of the fluorescent polymer obtained in Example 2.

[0024] Figure 4 : This is the fluorescence spectrum of the fluorescent polymer obtained in Example 2.

[0025] Figure 5 : This is the fluorescence spectrum of the fluorescent polymer obtained in Example 3.

[0026] Figure 6 : This is the fluorescence spectrum of the fluorescent polymer obtained in Example 4.

[0027] Figure 7 : This is the fluorescence spectrum of the fluorescent polymer obtained in Example 5.

[0028] Figure 8 : This is the fluorescence spectrum of the fluorescent polymer obtained in Example 6. Detailed Implementation

[0029] The present invention will be described in detail below with reference to embodiments. However, it should be understood that the following embodiments are merely illustrative examples of implementation of the present invention and are not intended to limit the scope of the present invention.

[0030] All monomers used in the following embodiments of the present invention are commercially available or easily synthesized.

[0031] in,

[0032] Alkyne monomer It can be synthesized according to the method reported in the literature (ACS Appl. Polym. Mater. 2024, 6, 4127-4137).

[0033] Example 1

[0034] Propanolamine (0.075 g, 1 equiv) and ethylene glycol dipropynate (0.249 g, 1.5 equiv) were added to a 5 mL single-necked polymerization flask and stirred in air at 60 °C for 24 h. After the reaction was completed, the mixture was precipitated with n-hexane to obtain a hyperbranched fluorescent polymer with a yield of 80% and an E configuration of 98%. The structure of the branched polymer was confirmed by 1H NMR spectroscopy (as per the instruction manual). Figure 1 (As shown). Volume exclusion chromatography characterization revealed that the polymer had a weight-average molecular weight of 18800 g / mol and a molecular weight distribution of 2.65, indicating that this method can prepare branched fluorescent polymers with high molecular weights. Fluorescence spectroscopy analysis showed that the excitation and emission wavelengths of this fluorescent polymer were 463 nm and 520 nm, respectively, exhibiting yellow fluorescence (as shown in the attached instruction manual). Figure 2 As shown in the figure, the solid-state fluorescent quantum yield is 32.97%.

[0035] The chemical formulas involved in the above reaction are as follows:

[0036]

[0037] Example 2

[0038] Isopropanolamine (0.075 g, 1 equiv), ethylene glycol dipropynate (0.249 g, 1.5 equiv), and dichloromethane (0.3 mL) were added to separate 10 mL single-necked polymerization flasks and stirred at 60 °C in air for 24 h. After the reaction was complete, the polymer was precipitated with n-hexane to obtain a branched fluorescent polymer with a yield of 88% and an E configuration of 99%. Volume exclusion chromatography characterization showed that the polymer had a weight-average molecular weight of 16200 g / mol and a molecular weight distribution of 1.89, indicating that this method can prepare branched fluorescent polymers with high molecular weights. Its 1H NMR spectrum is shown in the attached specification. Figure 3 The fluorescence spectrum is shown in the attached instruction manual. Figure 4 As shown in the figure, the excitation and emission wavelengths of this fluorescent polymer were measured to be 471 nm and 523 nm, respectively, exhibiting yellow fluorescence characteristics and a solid-state fluorescence quantum yield of 34.08%.

[0039] The chemical formulas involved in the above reaction are as follows:

[0040]

[0041] Example 3

[0042] Diethanolamine (0.105 g, 1 equiv), ethylene glycol dipropynate (0.249 g, 1.5 equiv), and N,N-dimethylformamide (0.3 mL) were added to separate 10 mL single-necked polymerization flasks and stirred at 60 °C in air for 12 h. After the reaction was complete, the polymer was precipitated with diethyl ether to obtain a branched fluorescent polymer with a yield of 88% and an E configuration of 95%. Volume exclusion chromatography characterization showed that the polymer had a weight-average molecular weight of 24800 g / mol and a molecular weight distribution of 2.45, indicating that this method can prepare branched fluorescent polymers with high molecular weights. Its fluorescence spectrum is shown in the attached specification. Figure 5 As shown in the figure, the excitation and emission wavelengths of this branched fluorescent polymer were measured to be 490 nm and 555 nm, respectively, exhibiting yellow fluorescence characteristics and a solid-state fluorescence quantum yield of 33.73%.

[0043] The chemical formulas involved in the above reaction are as follows:

[0044]

[0045] Example 4

[0046] Bis(2-hydroxypropyl)amine (0.133 g, 1 equiv), ethylene glycol dipropynate (0.2490 g, 1.5 equiv), and dichloromethane (0.3 mL) were added to separate 10 mL single-necked polymerization flasks and stirred at 45 °C in air for 12 h. After the reaction was complete, the polymer was precipitated with diethyl ether to obtain a branched fluorescent polymer with a yield of 78% and an E configuration of 96%. Volume exclusion chromatography characterization showed that the polymer had a weight-average molecular weight of 22600 g / mol and a molecular weight distribution of 2.48, indicating that this method can prepare branched fluorescent polymers with high molecular weights. Proton NMR spectroscopy confirmed the structure of the branched fluorescent polymer (as per the instruction manual). Figure 3 (As shown). Fluorescence spectroscopy measurements showed that the excitation and emission wavelengths of this fluorescent polymer were 482 nm and 545 nm, respectively, exhibiting orange fluorescence (as shown in the attached instruction manual). Figure 6 As shown in the figure, the solid-state fluorescent quantum yield is 30.18%.

[0047] The chemical formulas involved in the above reaction are as follows:

[0048]

[0049] Example 5

[0050] 1,3-bis[tris(hydroxymethyl)methylamino]propane (0.282 g, 1 equiv), ethylene glycol dipropynate (0.2490 g, 1.5 equiv), and dichloromethane (0.3 mL) were added to separate 10 mL single-necked polymerization flasks and stirred at 45 °C in air for 12 h. After the reaction was complete, the polymer was precipitated with diethyl ether to obtain a branched fluorescent polymer with a yield of 88%. Volumetric exclusion chromatography characterization showed that the polymer had a weight-average molecular weight of 34200 g / mol and a molecular weight distribution of 3.18, indicating that this method can prepare branched fluorescent polymers with high molecular weights. Fluorescence spectroscopy showed that the excitation and emission wavelengths of the fluorescent polymer were 423 nm and 484 nm, respectively, exhibiting blue fluorescence (as per the instruction manual). Figure 7 As shown in the figure, the solid-state fluorescent quantum yield is 33.28%.

[0051] The chemical formulas involved in the above reaction are as follows:

[0052]

[0053] Example 6

[0054] N,N'-bis(2-hydroxyethyl)ethylenediamine (0.148 g, 1 equiv), ethylene glycol dipropynate (0.332 g, 2 equiv), and DMF (0.3 mL) were added to 10 mL single-necked polymerization flasks and stirred at 45 °C in air for 12 h. After the reaction was complete, the polymer was precipitated with diethyl ether to obtain a branched fluorescent polymer with a yield of 82%. Volumetric exclusion chromatography characterization showed that the polymer had a weight-average molecular weight of 39200 g / mol and a molecular weight distribution of 3.62, indicating that this method can prepare branched fluorescent polymers with high molecular weights. Fluorescence spectroscopy showed that the excitation and emission wavelengths of the fluorescent polymer were 446 nm and 513 nm, respectively, exhibiting green fluorescence (as per the instruction manual). Figure 8 As shown in the figure, the solid-state fluorescent quantum yield is 36.28%.

[0055] The chemical formulas involved in the above reaction are as follows:

[0056]

[0057] Comparative Example 1

[0058] Triethanolamine (0.1492 g, 1 equiv), ethylene glycol dipropynate (0.249 g, 1.5 equiv), and dichloromethane (0.3 mL) were added separately to 10 mL single-necked polymerization flasks and reacted at 25 °C in air for 12 h with stirring. After the reaction was completed, the polymer was precipitated with diethyl ether to obtain a branched fluorescent polymer (see Example 10 described in Chinese Invention Patent CN114716659A), with a yield of 88%. Volumetric exclusion chromatography characterized the polymer, showing a weight-average molecular weight of 69200 g / mol and a molecular weight distribution of 3.04. Fluorescence spectroscopy revealed that the excitation and emission wavelengths of the fluorescent polymer were 420 nm and 495 nm, respectively, exhibiting blue-green fluorescence characteristics, with a solid-state fluorescence quantum yield of 13.52%.

[0059]

[0060] Comparative Example 2

[0061] Triisopropanolamine (0.1912 g, 1 equiv), ethylene glycol dipropynate (0.1660 g, 1 equiv), and dichloromethane (0.3 mL) were added separately to 10 mL single-necked polymerization flasks. The mixtures were stirred and reacted at 25 °C for 12 h in air, followed by precipitation with diethyl ether to obtain a branched fluorescent polymer (see Example 12 described in Chinese Invention Patent CN114716659A), with a yield of 81%. Volumetric exclusion chromatography characterized the polymer, showing a weight-average molecular weight of 20200 g / mol and a molecular weight distribution of 2.94. Fluorescence spectroscopy revealed that the excitation and emission wavelengths of the fluorescent polymer were 375 nm and 440 nm, respectively, exhibiting blue fluorescence with a solid-state fluorescence quantum yield of 9.85%.

[0062]

[0063] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A branched fluorescent polymer, characterized in that, This product is generated by a click reaction between an amino alcohol monomer and an alkynyl monomer. During the reaction, the alkynyl group in the alkynyl monomer first clicks with the primary or secondary amino group in the amino alcohol monomer, and then clicks with the hydroxyl group in the primary or secondary amino alcohol monomer. The alkynyl monomer molecular chain is capped at both ends by two alkynyl groups. The amino alcohol monomer includes a primary amino alcohol monomer or a secondary amino alcohol monomer containing at least two hydroxyl groups. The alkynyl monomer includes a dialkynyl monomer or a polyalkynyl monomer whose molecular chain is capped at both ends by two alkynyl groups. The dialkynyl monomer includes the following structural formula: ； ； ； ； In the above structural formula, m is 1~3, and n>2; Polyacetylenic monomers include the following structural formulas: 。 2. The branched fluorescent polymer according to claim 1, characterized in that, The diacetyl monomer includes ethylene glycol dipropynate.

3. The branched fluorescent polymer according to claim 1, characterized in that, The primary amino alcohol monomers include monohydroxy primary amino alcohols, dihydroxy primary amino alcohols, or polyhydroxy primary amino alcohols.

4. The branched fluorescent polymer according to claim 3, characterized in that, The monohydroxy primary amino alcohol includes propanolamine or isopropanolamine.

5. The branched fluorescent polymer according to claim 3, characterized in that, The dihydroxy primary amino alcohol includes diethanolamine, bis(2-hydroxypropyl)amine, or N,N'-bis(2-hydroxyethyl)ethylenediamine.

6. The branched fluorescent polymer according to claim 3, characterized in that, The polyhydroxy primary amino alcohol includes 1,3-bis[tris(hydroxymethyl)methylamino]propane.

7. The branched fluorescent polymer according to claim 1, characterized in that, During the click reaction, the primary amino alcohol monomer is 1,3-bis[tris(hydroxymethyl)methylamino]propane, and the alkynyl monomer is ethylene glycol dipropynate. The molar ratio of the primary amino alcohol monomer to the alkynyl monomer is 1:2.

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