A poly-pyrone, preparation method and application

Abstract

The application provides a preparation method and application of poly-pyrone, and belongs to the field of fluorescent materials and preparation technology.The preparation method of the poly-pyrone comprises the following steps: mixing malonic acid, acetic anhydride and dimethylamino pyridine in a molar ratio of 1:2-10:0.001-0.1, continuously stirring at 110-170 DEG C for 5-10 hours, and obtaining a crude product through reaction; mixing the crude product with a precipitating reagent, stirring for 5-60 minutes, then performing vacuum filtration on the mixed slurry, and obtaining the poly-pyrone through washing and drying of the separated solid powder.Compared with the arocondensation method without catalyst, the preparation method provided by the application can increase the polymerization degree of the poly-pyrone by 10-200 times, and the obtained poly-pyrone is non-toxic, can realize visible light-near infrared light emission, and greatly expands the application range and application field.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fluorescent materials and preparation technology, and particularly relates to a poly-pyrone, a preparation method and application. BACKGROUND

[0002] Organic photoluminescent materials have developed into a large class of very important optical materials, and have important applications in various optical display fields. Poly-pyrone is a conjugated compound with adjustable molecular weight, and is non-toxic and environmentally friendly.

[0003] Pyrone (English name pyrone) is a ketone derivative of pyran, and is a kind of six-membered oxygen-containing heterocyclic compound with a molecular formula of C5H4O2. Like pyran, pyrone can have two isomers according to the positions of the double bond and the carbonyl group in the ring, namely, alpha-pyrone (alpha-pyrone) and gamma-pyrone (gamma-pyrone). Among them, alpha-pyrone is also known as coumalin, which can be regarded as the lactone of 5-hydroxy-2,4-pentadienoic acid. It is a colorless liquid with a hay smell, which is miscible with water and soluble in ethanol; gamma-pyrone is a colorless hygroscopic crystal, which is easily soluble in water, diethyl ether, chloroform and acetic acid. The two pyran nuclei have not been found in nature, and their derivatives exist naturally. The structure of pyrone widely exists in natural products.

[0004] The existing synthesis method of poly-pyrone can be roughly divided into three categories: the first category is a method without using solvent and catalyst, and the yield is extremely low; the second category is a method using solvent and catalyst, and the yield can reach 80%, but due to the use of solvent and catalyst, the preparation process has toxic or radioactive environmental pollution, and is not suitable for use in the vicinity of people or their environment; the third category is a method using solvent without using catalyst, such as aromatic condensation, but the yield is only about 15%, and the number of pyrone polymerization units in the obtained polymer is 8-17, the polymerization degree is low and the impurities are more.

[0005] In view of all the existing synthesis methods, the polymerization degree of the obtained polymer does not exceed 40 polymerization units, and the existing research only shows that the poly-pyrone synthesized by the condensation-aromatic method has a maximum fluorescence emission in the blue light band in the solution, and cannot have adjustable performance in a larger wavelength range, and the research in the optical field is blank, and the synthesis method and application range need to be developed. SUMMARY

[0006] In view of the above problems in the prior art, the present application provides a poly-pyrone, a preparation method and application, and the preparation method has the advantages of high yield of target product, and the obtained poly-pyrone is non-toxic, has high polymerization degree, and has visible light-near infrared light emission performance.

[0007] The specific application content is as follows:

[0008] In a first aspect, the present application provides a preparation method of poly-pyrone, comprising the following steps:

[0009] S1, mixing malonic acid, acetic anhydride and dimethylamino pyridine in a molar ratio of 1:2-10:0.001-0.1, and then stirring at 110-170℃ for 5-10h to obtain a crude product;

[0010] S2, mixing the crude product with a precipitating agent, stirring for 5-60min, then vacuum filtering the mixed slurry, and washing and drying the separated solid powder to obtain the poly-pyrone.

[0011] Optionally, in step S1, the reaction to obtain the crude product is carried out in a heating reflux device, and the method comprises: adding the malonic acid, acetic anhydride and dimethylamino pyridine into a three-necked flask, using the three-necked flask to build the heating reflux device, and discharging residual air in the device.

[0012] Optionally, the discharging of the residual air in the device comprises: introducing a purge gas into the three-necked flask for 10-60min to discharge the residual air in the device.

[0013] The purge gas is He, Ar or N2.

[0014] Optionally, in step S1, before the operation of stirring at 110-170℃ for 5-10h, the method further comprises: preheating the mixture of the malonic acid, acetic anhydride and dimethylamino pyridine to fully dissolve the reaction raw materials.

[0015] Optionally, the preheating temperature is 70-110℃, and the preheating time is 5-60min.

[0016] Optionally, in step S2, the washing comprises: using the precipitating agent as a washing agent to wash sufficiently for 3-5 times.

[0017] The drying temperature is 80-120℃.

[0018] Optionally, the precipitating agent is at least one of ethanol, tert-butyl alcohol, ethyl acetate, water and diethyl ether.

[0019] In a second aspect, the present application provides a poly-pyrone obtained by the preparation method of the first aspect, wherein the poly-pyrone is a continuous structure having 20-5000 pyrone polymerization units of formula I:

[0020]

[0021] The ratio of the alpha pyrone unit to the gamma pyrone unit in the continuous structure is 1-4:1.

[0022] Optionally, the fluorescence emission range of the poly-pyrone is visible light-near infrared light.

[0023] In a third aspect, the application provides a poly-pyrone prepared by the method of the first aspect, which is used as an organic photoluminescent material in the preparation of an organic electroluminescent device.

[0024] Compared with the prior art, the application has the following advantages:

[0025] The application provides a preparation method of a poly-pyrone, which comprises the following steps: mixing malonic acid, acetic anhydride and dimethylamino pyridine in a molar ratio of 1:2-10:0.001-0.1, and then continuously stirring at 110-170 DEG C for 5-10 hours to obtain a crude product; mixing the crude product with a precipitating reagent, stirring for 5-60 minutes, and then performing vacuum filtration on the mixed slurry, so that the separated solid powder is washed and dried to obtain the poly-pyrone. Compared with an aro-condensation method without a catalyst, the preparation method provided by the application can increase the polymerization degree of the poly-pyrone by 10-200 times, and the obtained poly-pyrone is non-toxic, can emit visible light-near infrared light, and greatly expands the application range and application field. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0027] Figure 1 A flow chart of the preparation method of the poly-pyrone provided by the embodiments of the application is shown;

[0028] Figure 2 An excitation and emission spectrum of the poly-pyrone in a thin film state provided by the embodiments of the application is shown;

[0029] Figure 3 A fluorescence spectrum of a 4-valerolactone solution of the poly-pyrone containing different ions provided by the embodiments of the application is shown. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described in the present application with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting on the present application and its applications or uses. Based on the embodiments in the present application, any person skilled in the art obtains any product identical or similar to the present application under the inspiration of the present application or combines the present application with other prior art features, which falls within the protection scope of the present application. In addition, all other embodiments obtained by the ordinary skilled in the art without creative labor are within the protection scope of the present application.

[0031] If the specific experimental steps or conditions are not indicated in the embodiments, the operation or conditions can be performed according to the conventional experimental steps described in the prior art. If the manufacturers of the reagents and other instruments are not indicated, the reagents are conventional reagent products that can be obtained from the market. In addition, the accompanying drawings are only schematic diagrams of the embodiments of the present application, and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and thus repeated description thereof will be omitted. Some block diagrams shown in the drawings are functional entities, and do not necessarily correspond to physically or logically independent entities.

[0032] The technologies, methods and devices known to the person skilled in the relevant art can not be discussed in detail, but under appropriate circumstances, the technologies, methods and devices should be regarded as part of the specification of the present application.

[0033] In the description of the present application, it should be understood that the use of the words "first", "second" and the like to qualify elements is only for the convenience of distinguishing the corresponding elements, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0034] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0035] The present application is based on solving the problems of environmental pollution in the preparation process of the existing poly-pyrone, low yield of target product, low degree of polymerization of the obtained poly-pyrone, and small wavelength range of the fluorescence of the poly-pyrone, and provides a poly-pyrone, a preparation method and an application, and the specific implementation content is as follows:

[0036] In a first aspect, the present application provides a preparation method of a poly-pyrone, Figure 1 The preparation method of the poly-pyrone provided by the embodiments of the present application is shown in the flow chart of the preparation method of the poly-pyrone, as shown in the figure, the preparation method comprises the following steps: Figure 1 ​

[0037] S1, mixing malonic acid, acetic anhydride and dimethylamino pyridine in a molar ratio of 1:2-10:0.001-0.1, continuously stirring at 110-170℃ for 5-10h, and obtaining a crude product by reaction;

[0038] In the implementation of the operation process of step S1, the reaction is specifically carried out in a heating reflux device, and the operation process comprises: adding malonic acid, acetic anhydride and dimethylamino pyridine into a three-necked flask, then using the three-necked flask to build a heating reflux device, and then introducing a purge gas into the three-necked flask for 10-60min to discharge residual air in the device. The purge gas can be He, Ar or N2.

[0039] Further, after discharging the residual air in the device, the three-necked flask containing malonic acid, acetic anhydride and dimethylamino pyridine is preheated first, the preheating temperature is 70-110℃, and the preheating time is 5-60min, so that the reaction raw materials are fully dissolved; after the reaction raw materials are fully dissolved, the heating temperature is increased to 110-170℃ to make the polymerization reaction fully proceed, and this reaction process can be regarded as being completed by three steps:

[0040] The first step, malonic acid and acetic anhydride first react under the action of dimethylamino pyridine to generate a long-chain intermediate, and the reaction formula is as follows:

[0041]

[0042] The second step, the long-chain intermediate further loses carboxyl to form carbon trioxide (C3O2), and the reaction formula is as follows:

[0043]

[0044] The third step, since acetic anhydride is excessive in the reaction raw materials, the carbon trioxide generated in the system and the remaining unreacted acetic anhydride and dimethylamino pyridine further polymerize to finally generate poly-pyrone, and the reaction formula is as follows:

[0045]

[0046] As can be seen from the above reaction process, dimethylamino pyridine acts as a catalyst for the first step reaction, promotes the reaction between malonic acid and acetic anhydride to form an intermediate, and then one molecular weight of the intermediate loses two molecular weights of acetic acid to obtain a large amount of carbon trioxide (C3O2); at the same time, dimethylamino pyridine reacts with the remaining unreacted acetic anhydride to form acetate ions, which initiates the polymerization reaction of C3O2, thereby generating poly-pyrone.

[0047] S2, mixing the crude product with a precipitation reagent, stirring for 5-60min, then vacuum filtering the mixed slurry, and obtaining the poly-pyrone by washing and drying the separated solid powder.

[0048] In the step S2, in order to extract the poly-pyrone with high purity from the reaction system, the present application uses at least one of ethanol, tert-butyl alcohol, ethyl acetate, water and diethyl ether as the precipitating reagent to mix with the crude product. Due to the difference in solubility of the poly-pyrone in the precipitating reagent and acetic anhydride, the poly-pyrone in the mixed slurry is precipitated under stirring, and the solid powder of the poly-pyrone is separated by vacuum filtration. The solid powder is washed by the precipitating reagent for 3-5 times, and then dried (at a temperature of 80-120°C), so as to obtain the poly-pyrone with purity of more than 95%.

[0049] In the preparation method, the dimethylamino pyridine as the catalyst in the first step reaction promotes the reaction between the malonic acid and the acetic anhydride to form the intermediate, and then promotes the formation of a large amount of monomer C3O2 of the poly-pyrone through the de-acetic acid reaction. The polymerization degree of the poly-pyrone is increased by 10-200 times, and the obtained poly-pyrone is non-toxic and can realize the visible light-near infrared luminescence, so as to greatly expand the application range and application field.

[0050] In the second aspect, the present application provides a poly-pyrone obtained by the preparation method of the first aspect, and the poly-pyrone has a continuous structure with 20-5000 pyrone polymerization units shown in the formula I.

[0051]

[0052] In the continuous structure, the ratio of the alpha pyrone unit to the gamma pyrone unit is 1-4:1.

[0053] Since the poly-pyrone provided by the present embodiment has the continuous structure with 20-5000 pyrone polymerization units shown in the formula I, the number of the continuous structure units, i.e. the length of the conjugated path, is adjustable, which determines the larger wavelength range of the fluorescence that can be realized.

[0054] In the third aspect, the present application provides an application of the poly-pyrone obtained by the preparation method of the first aspect, and the poly-pyrone is used as an organic photoluminescent material and applied in the preparation of the organic photoluminescent related devices. In particular, the poly-pyrone can be used as a light-excited anti-counterfeiting display material, and has good light stability.

[0055] In order for those skilled in the art to more clearly understand the present application, the poly-pyrone, the preparation method and the application of the present application are described in detail through the following examples.

[0056] Example 1

[0057] The acetic anhydride, malonic acid and dimethylamino pyridine are weighed into a three-necked flask. The molar ratio of malonic acid to acetic anhydride can be controlled to be 1:3; the molar ratio of malonic acid to dimethylamino pyridine is 1:0.01. A refluxing experimental device is set up, and then a purge gas (Ar) is introduced into the three-necked flask for 25 min to sufficiently remove residual air in the device.

[0058] The three-necked flask is preheated to 110°C and kept for 30 min to make the reaction raw materials sufficiently dissolved, and the stirring speed is 150 r / min. The temperature is raised to 130°C and kept for 5 h to obtain the reaction product, and the stirring speed is 300 r / min. The reaction is stopped, and the reaction product is naturally cooled to room temperature, and at the same time, a purge gas (Ar) is introduced into the three-necked flask for 50 min to sufficiently remove residual product gas in the reaction device.

[0059] The reaction product is transferred into a beaker, and 250 ml of a precipitation reagent (ethanol) is added, and magnetic stirring is performed for 25 min. The above slurry is vacuum filtered to obtain a solid powder, and the solid powder is washed with the precipitation reagent for 5 times. The washed solid powder is placed in an oven and dried at 105°C to obtain a product powder with a purity of greater than 95%.

[0060] The prepared poly-pyrone is dissolved in a DMF solvent, and it is measured by gel permeation chromatography (GPC) that the average continuous structure of the poly-pyrone is up to 40 polymerization units, and the highest continuous structure is up to 400 polymerization units. Using a thermogravimetric-mass spectrometry-infrared combined device, the poly-pyrone powder is heated to 1000°C (Ar), and by testing the proportion of CO2 and CO generated in the pyrolysis process of the sample, it is measured that the proportion of α-pyrone units to γ-pyrone units in the structure of the poly-pyrone is 2:1.

[0061] The obtained poly-pyrone is dissolved in a 4-pentanolactone solvent to form a solution, and then the above solution is respectively dropped onto a silicon wafer or a quartz wafer substrate, and dried at 60°C to prepare a thin film.

[0062] Figure 2 The excitation and emission spectra of the poly-pyrone in a thin film state provided by the embodiment of the present application are shown in FIG. 1. Figure 2 As shown in FIG. 1, the prepared thin film can realize fluorescent emission in the visible light-near infrared range.

[0063] Further, the poly-pyrone is dissolved in 4-pentanolactone, and then the above solution is respectively dropped onto a substrate containing Li + , Na + , K + , Mg 2+ , Ca 2+ , Cu 2+ , Al 3+ , Ni 2+ or Fe 3+The fluorescence intensity and emission wavelength of the mixed solution are characterized by steady-state fluorescence spectrum in an aqueous solution of ions.

[0064] Figure 3 The fluorescence spectrum of the 4-pentanolactone solution containing different ions of the poly-pyrone provided by the embodiment of the application is shown. Figure 3 As shown in the figure, the results show that, compared with the blank 4-pentanolactone solution of poly-pyrone, Li + , Na + , K + ions increase the fluorescence intensity, and the maximum emission wavelength changes little; Mg 2+ , Ca 2+ and Al 3+ ions increase the fluorescence intensity, and the maximum emission wavelength is blue-shifted; Cu 2+ and Ni 2+ ions decrease the fluorescence intensity, and the maximum emission wavelength is blue-shifted; and Fe 3+ ions significantly decrease the fluorescence intensity. This shows that the poly-pyrone prepared in the embodiment has great application potential in the field of fluorescent metal ion probes.

[0065] Example 2

[0066] Acetic anhydride, malonic acid and dimethylamino pyridine are weighed in a three-necked flask. The molar ratio of malonic acid to acetic anhydride can be controlled to be 1:4; and the molar ratio of malonic acid to dimethylamino pyridine is 1:0.01. A refluxing experimental device is built, and then a purge gas (He) is introduced into the three-necked flask for 40 min to sufficiently discharge residual air in the device.

[0067] The three-necked flask is preheated to 100℃ and kept for 20 min to make the reaction raw materials fully dissolved, and the stirring speed is 400 r / min. The temperature is increased to 120℃ and kept for 6 h to obtain the reaction product, and the stirring speed is 400 r / min. The reaction is stopped, and the reaction product is naturally cooled to room temperature, and at the same time, a purge gas (He) is introduced into the three-necked flask for 30 min to sufficiently discharge residual product gas in the reaction device.

[0068] The reaction product was transferred to a beaker and 250 ml of precipitation reagent (t-butanol) was added and stirred magnetically for 35 min. The slurry was filtered under vacuum to obtain a solid powder which was washed thoroughly with precipitation reagent for 3 times. The washed solid powder was placed in an oven and dried at 120 °C to obtain the product powder with purity greater than 95%. The prepared poly-pyrone was dissolved in NMP solvent and the average length of the continuous structure of the poly-pyrone was measured to be up to 90 polymerized units by gel permeation chromatography (GPC) and up to 600 polymerized units. The ratio of alpha-pyrone units to gamma-pyrone units in the structure was 3:1 by testing the ratio of CO2 and CO produced during the pyrolysis of the sample using a thermogravimetric-mass spectrometry-infrared combined instrument by heating the poly-pyrone powder to 1000 °C (He).

[0069] The obtained poly-pyrone was dissolved in DMSO solvent to form a solution, and then the solution was added dropwise to a silicon wafer or quartz wafer substrate, respectively, and dried at 80 °C to obtain a thin film. The obtained thin film was tested for fluorescence emission in the visible-near infrared range, and the test results were highly similar to those of Example 1, and the figures used to characterize the results are not repeated.

[0070] Further, the poly-pyrone was dissolved in 4-pentanone, and then the solution was added dropwise to an aqueous solution containing Li + , Na + , K + , Mg 2+ , Ca 2+ , Cu 2+ , Al 3+ , Ni 2+ or Fe 3+ ions, respectively, and the fluorescence intensity and emission wavelength of the mixed solution were characterized by steady-state fluorescence spectroscopy. The results of the characterization figures were highly similar to those of Example 1, and are not repeated.

[0071] Example 3

[0072] Acetic anhydride, malonic acid and dimethylamino pyridine were weighed into a three-necked flask. The molar ratio of malonic acid to acetic anhydride was controlled to be 1:5, and the molar ratio of malonic acid to dimethylamino pyridine was 1:0.003. A refluxing experimental device was set up, and then a purge gas (He) was introduced into the three-necked flask for 50 min to sufficiently remove residual air in the device.

[0073] The three-neck flask was preheated to 100°C for 15 min to allow the reaction materials to dissolve completely, and the stirring speed was 300 r / min. The temperature was raised to 130°C and maintained for 10 h to obtain the reaction product, and the stirring speed was 500 r / min. The reaction was stopped, and the reaction product was naturally cooled to room temperature, while the three-neck flask was purged with a purge gas (He) for 30 min to fully exhaust the residual product gas in the reaction device.

[0074] The reaction product was transferred to a beaker, and 400 ml of a precipitation reagent (50% water, 50% ethanol) was added, and magnetic stirring was performed for 20 min. The above slurry was vacuum filtered to obtain a solid powder, and the solid powder was washed with the precipitation reagent for 4 times. The washed solid powder was placed in an oven and dried at 90°C to obtain a product powder with a purity of greater than 95%. The prepared poly-pyrone was dissolved in NMP solvent, and the average continuous structure of the poly-pyrone was up to 35 polymerization units, and the highest continuous structure was up to 150 polymerization units, as measured by gel permeation chromatography (GPC). Using a thermogravimetric-mass spectrometry-infrared combined device, the poly-pyrone powder was heated to 1000°C (He), and the ratio of α-pyrone units to γ-pyrone units in the structure was 3.5:1 by testing the ratio of CO2 and CO generated during the pyrolysis of the sample.

[0075] The obtained poly-pyrone was dissolved in NMP solvent to form a solution, and then the above solution was added dropwise to a silicon wafer or a quartz wafer substrate, and dried at 100°C to obtain a thin film. The obtained thin film was tested for fluorescence emission in the visible-near infrared range, and the test results were highly similar to those of Example 1, and the figures used to characterize the results are not repeated.

[0076] Further, the poly-pyrone was dissolved in 4-pentanolactone, and then the above solution was added dropwise to an aqueous solution containing Li + , Na + , K + , Mg 2+ , Ca 2+ , Cu 2+ , Al 3+ , Ni 2+ or Fe 3+ ions, respectively, and the fluorescence intensity and emission wavelength of the mixed solution were characterized by steady-state fluorescence spectroscopy. The results of the characterization figures were highly similar to those of Example 1, and are not repeated.

[0077] Example 4

[0078] Acetic anhydride, malonic acid and dimethylamino pyridine were weighed into a three-necked flask. The molar ratio of malonic acid to acetic anhydride was controlled to be 1:10, and the molar ratio of malonic acid to dimethylamino pyridine was 1:0.006. A refluxing experimental device was set up, and then a purge gas (Ar) was introduced into the three-necked flask for 60 min to sufficiently remove residual air in the device.

[0079] The three-necked flask was preheated to 110°C and maintained for 45 min to allow the reaction materials to be fully dissolved, with a stirring speed of 500 r / min. The temperature was raised to 150°C and maintained for 8 h to obtain the reaction product, with a stirring speed of 800 r / min. The reaction was stopped, and the reaction product was naturally cooled to room temperature, while a purge gas (Ar) was introduced into the three-necked flask for 30 min to sufficiently remove residual product gas in the reaction device.

[0080] The reaction product was transferred to a beaker, and 400 ml of a precipitation reagent (ethyl acetate) was added, and magnetic stirring was performed for 40 min. The above slurry was vacuum-filtered to obtain a solid powder, which was washed with the precipitation reagent (ethyl acetate) for 5 times. The washed solid powder was placed in an oven and dried at 110°C to obtain a product powder with a purity of greater than 95%. The prepared poly-pyrone was dissolved in NMP solvent, and the average continuous structure of the poly-pyrone was measured by gel permeation chromatography (GPC) to be up to 110 polymerization units, and the maximum continuous structure was up to 720 polymerization units. Using a thermogravimetric-mass spectrometry-infrared combined device, the poly-pyrone powder was heated to 1000°C (He), and by testing the ratio of CO2 and CO generated during the pyrolysis of the sample, the ratio of α-pyrone units to γ-pyrone units in the structure was 4:1.

[0081] The obtained poly-pyrone was dissolved in DMF solvent to form a solution, and then the above solution was added dropwise to a silicon wafer or quartz wafer substrate, which was dried at 80°C to obtain a thin film. The obtained thin film was tested for fluorescence emission in the visible-near infrared range, and the test results were highly similar to those of Example 1, and the figures used to characterize the results are not repeated.

[0082] Further, the poly-pyrone was dissolved in 4-pentanone, and then the above solution was added dropwise into an aqueous solution containing Li + ,Na + ,K + ,Mg 2+ ,Ca 2+ ,Cu 2+ ,Al 3+ ,Ni 2+ or Fe 3+ ions, respectively, and the fluorescence intensity and emission wavelength of the mixed solution were characterized by steady-state fluorescence spectroscopy. The results of the characterization figures were highly similar to those of Example 1, and are not repeated.

[0083] Example 5

[0084] The acetic anhydride, malonic acid and dimethylamino pyridine were weighed into a three-necked flask. The molar ratio of malonic acid to acetic anhydride was controlled to be 1:5; the molar ratio of malonic acid to dimethylamino pyridine was 1:0.05. The refluxing experimental device was set up, and then the three-necked flask was purged with a purge gas (N2) for 60 min to sufficiently discharge the residual air in the device.

[0085] The three-necked flask was preheated to 100°C and maintained for 15 min to allow the reaction materials to be fully dissolved, with a stirring speed of 400 r / min. The temperature was raised to 150°C and maintained for 5 h to obtain the reaction product, with a stirring speed of 1500 r / min. The reaction was stopped, and the reaction product was naturally cooled to room temperature, while the three-necked flask was purged with a purge gas (N2) for 10 min to sufficiently discharge the residual product gas in the reaction device.

[0086] The reaction product was transferred to a beaker, and 300 ml of a precipitation reagent (diethyl ether) was added, and the mixture was magnetically stirred for 15 min. The above slurry was vacuum-filtered to obtain a solid powder, which was washed with the precipitation reagent for 3-5 times. The washed solid powder was placed in an oven and dried at 80°C to obtain a product powder with a purity of greater than 95%. The prepared poly-pyrone was dissolved in an NMP solvent, and the average continuous structure of the poly-pyrone was measured by gel permeation chromatography (GPC) to be up to 150 polymerization units, and the maximum continuous structure was up to 2000 polymerization units. Using a thermogravimetric-mass spectrometry-infrared combined device, the poly-pyrone powder was heated to 1000°C (He), and by testing the proportion of CO2 and CO generated during the pyrolysis of the sample, the proportion of α-pyrone units to γ-pyrone units in the structure was 3:1.

[0087] The obtained poly-pyrone was dissolved in a 4-pentanol solution to form a solution, and then the solution was added dropwise to a silicon wafer or a quartz wafer substrate, which was dried at 80°C to obtain a thin film. The obtained thin film was tested for fluorescence emission in the visible light-near infrared range, and the test results were highly similar to those of Example 1, and the figures used to characterize the results are not repeated.

[0088] Further, the poly-pyrone was dissolved in 4-pentanol, and then the solution was added dropwise to a substrate containing Li + , Na + , K + , Mg 2+ , Ca 2+ , Cu 2+ , Al 3+ , Ni 2+ or Fe 3+The fluorescence intensity and emission wavelength of the mixed solution were characterized by steady-state fluorescence spectrum in the aqueous solution of ions. The results of the characterization in the accompanying drawings were highly similar to those of Example 1, and were not repeatedly given.

[0089] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present specification.

[0090] For the method embodiments, for the sake of simple description, they are all expressed as a combination of a series of actions, but those skilled in the art should know that the present application is not limited by the order of the described actions, because according to the present application, certain steps can be performed in other order or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the actions and components involved are not necessarily necessary for the present application.

[0091] The above describes in detail the poly-pyrone, the preparation method and the application provided by the present application. The principles and implementation manners of the present application are described by applying specific examples. The above embodiment description is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range will have changes; in view of the above, the content of the present specification should not be understood as a limitation of the present application.

Claims

1. A method for producing a poly-pyrone, characterized by, The preparation method comprises the following steps: S1, mixing malonic acid, acetic anhydride and dimethylamino pyridine in a molar ratio of 1:2-10:0.001-0.1, continuously stirring at 110-170 DEG C for 5-10 h, and obtaining a crude product by reaction; S2, mixing the crude product with a precipitating agent, stirring for 5-60 min, then vacuum filtering the mixed slurry, and obtaining the poly-pyrone by washing and drying the separated solid powder.

2. The method for preparing polypyranone according to claim 1, characterized in that, In step S1, the reaction to obtain the crude product is carried out in a heating reflux device, and the method comprises: adding the malonic acid, acetic anhydride and dimethylamino pyridine into a three-necked flask, using the three-necked flask to build the heating reflux device, and discharging residual air in the device.

3. The method for preparing polypyranone according to claim 2, characterized in that, The discharging of the residual air in the device comprises: introducing a purge gas into the three-necked flask for 10-60 min to discharge the residual air in the device. The purge gas is He, Ar or N2.

4. The method for preparing polypyranone according to claim 1, characterized in that, Before the operation of continuously stirring at 110-170 DEG C for 5-10 h, the method further comprises: preheating the mixture of the malonic acid, acetic anhydride and dimethylamino pyridine to make the reaction raw materials fully dissolved.

5. The method for preparing polypyranone according to claim 4, characterized in that, The preheating temperature is 70-110 DEG C, and the preheating time is 5-60 min.

6. The method for preparing polypyranone according to claim 1, characterized in that, In step S2, the washing comprises: using the precipitating agent as a washing agent to wash fully for 3-5 times. The drying temperature is 80-120 DEG C.

7. The method for preparing polypyranone according to claim 1 or 6, characterized in that, The precipitating agent is at least one of ethanol, tert-butyl alcohol, ethyl acetate, water and diethyl ether.

8. A poly(pyrone) obtained by the process according to any one of claims 1 to 7, characterized in that The poly-pyrone is a continuous structure with 20-5000 pyrone polymerization units shown in formula I: Formula I; In the continuous structure, the ratio of the alpha pyrone unit to the gamma pyrone unit is 1-4:

1.

9. The poly(pyrone) of claim 8, wherein, The fluorescence emission range of the poly-pyrone is visible light-near infrared light.

10. Use of poly(pyrone) obtained by the process according to any one of claims 1 to 6, characterized in that The poly-pyrone is used as an organic photoluminescent material and applied in the preparation of devices related to organic photoluminescence.

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