Photoluminescent persistent polymer, preparation method thereof and application thereof

Abstract

A photoluminescent persistent polymer is obtained by mixing and curing an epoxy resin monomer with an organic photo-generated free radical compound. Among them, the epoxy resin monomer has the chemical structure shown in Formula I: The organic photo-generated free radical compound is any one or more of the compounds shown in Formula II, Formula III or Formula IV. In the present invention, the epoxy resin provides a rigid matrix for the organic photo-generated free radical molecules, inhibits their non-radiative deactivation, and the oxidation-reduction center of the organic photo-generated free radical compound can generate radical cations after being irradiated by ultraviolet light, and form a stable long-afterglow material through electron transfer and recombination with the carbonyl groups on the main polymer chain, providing new ideas and methods for the development of photoluminescent persistent materials; its preparation is simple, the raw materials are easy to obtain, the cost is low, it is easy to industrialize, and it has high yield, good economy, is environmentally friendly, and has great application prospects and promotion value.

Description

Technical Field

[0001] The present invention relates to a photoinduced long-afterglow polymer, a preparation method thereof and an application thereof, belonging to the technical field of the preparation and application of luminescent polymers. Background Art

[0002] Long-afterglow luminescent materials, abbreviated as long-afterglow materials (English: Long-persistent luminescence, English abbreviation: LPL), also called energy storage luminescent materials, are a kind of photoluminescent materials and have many application scenarios, including luminescent (also called night light) ceramics, glass, paints, inks, plastics, fibers, etc.

[0003] Most of the long-afterglow materials reported in the prior art are based on rare metals or inorganic minerals. For example, the invention patent application "A Photoinduced Long-Afterglow Luminescent Material Composition and a Preparation Method Thereof" (application number: 00103309.3), etc. Since the luminescence principle of such long-afterglow materials is based on rare metals or inorganic minerals, the transparency is lacking. Therefore, to a great extent, it limits their application prospects.

[0004] The invention patent "Electroluminescent Polymer and a Preparation Method Thereof" (application number: 200710044052.9), the invention patent application "A Kind of Afterglow Luminescent Nanomaterial and a Preparation Method and Application Thereof" (application number: 202210134630.2), the invention patent application "A Photoinduced Luminescent Coordination Polymer with Afterglow Emission and a Preparation Method and Application Thereof" (application number: 202210684898.3), etc. prepare corresponding organic long-afterglow materials through organic phosphorus-containing photogroups or chlorophyllin photosensitizers or photoinduced luminescent coordination polymer molecules, etc. However, the preparation methods of such materials prepared by the prior art are relatively complex, the process route is long, the product quality is not easy to control, and there are deficiencies such as unstable afterglow generation and difficult regulation of luminescence phenomena. Summary of the Invention

[0005] To solve the deficiencies of the prior art, the embodiments of the present invention provide a photoinduced long-afterglow polymer, a preparation method thereof and an application thereof, aiming at:

[0006] Providing an organic radical photoinduced long-afterglow polymer with a simple preparation method and stable afterglow generation, and achieving the purpose of regulating different luminescence phenomena by adjusting the substituents in the doped organic photogenerated radical molecules, providing new ideas and methods for the preparation of photoinduced long-afterglow materials. At the same time, providing new materials and new choices for the preparation of photoinduced afterglow products for different purposes or for the application of products such as information encryption, information decryption, and anti-counterfeiting.

[0007] To achieve the above purpose, the present invention first provides a photoinduced long-afterglow polymer.

[0008] The photoluminescent long afterglow polymer is a doped polymer obtained by mixing and curing an epoxy resin monomer with an organic photo-generated free radical compound, where:

[0009] The epoxy resin monomer has a chemical structure as shown in Formula I:

[0010] The organic photo-generated free radical compound is any one or more of the compounds with the structures shown in Formula II, Formula III or Formula IV:

[0011] And

[0012] The R 1 is the structural group shown by the following R 11～19 :

[0013]

[0014] The R 2 is the atom or group shown by the following R 21～28 :

[0015]

[0016] Furthermore:

[0017] In the photoluminescent long afterglow polymer, the mass of the organic photo-generated free radical compound is 0.05-10% of the mass of the epoxy resin monomer.

[0018] Secondly, the present invention also provides a preparation method of the above-mentioned photoluminescent long afterglow polymer.

[0019] The preparation method of the photoluminescent long afterglow polymer includes the following steps:

[0020] Take the epoxy resin monomer and place it in a container, and stir evenly at room temperature;

[0021] Take the organic photo-generated free radical compound and add it to the above container, mix it with the epoxy resin monomer at room temperature, and stir evenly to obtain a mixed slurry;

[0022] Remove the bubbles in the mixed slurry, then pour the mixed slurry into a mold or coat and print it on other objects, and then heat and cure it by the gradient heating method. After the curing is completed and it cools down, the product of the photoluminescent long afterglow polymer with the shape of the mold can be taken out from the mold, or other objects coated and printed with images by the photoluminescent long afterglow polymer can be obtained.

[0023] Optionally:

[0024] The bubbles in the mixed slurry are removed by a centrifugal degassing method, that is, the mixed slurry is placed in a centrifuge tube, and then the centrifuge tube containing the mixed slurry is placed in a centrifuge for centrifugal operation to remove the bubbles.

[0025] Furthermore, the gradient heating method is performed according to the following operating procedures:

[0026] The mold containing the mixed slurry or other objects coated with the photoinduced long afterglow polymer and printed with an image are placed in a heater, and then heated to 80°C and kept warm for 2 hours, then heated to 100°C and kept warm for another 2 hours, and then heated in this way to 120°C, 140°C and 160°C in batches, and kept warm for 2 hours after each heating.

[0027] Further:

[0028] The epoxy resin monomer is prepared by stirring reaction of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate and 4-methylhexahydrophthalic anhydride at room temperature.

[0029] Further:

[0030] The preparation method of the above epoxy resin monomer also includes a catalyst, the catalyst is tetra-tert-butylammonium bromide, and the reaction materials have the following molar ratio:

[0031] 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate: 4-methylhexahydrophthalic anhydride: tetra-tert-butylammonium bromide = 1: (1.70-1.80): (0.090-0.095).

[0032] Furthermore, the preparation method of the organic photogenerated free radical compound having the structure of Formula II is as follows:

[0033] Dihydrophenazine, R 1 -bromide, palladium acetate, sodium tert-butyl alcohol, and tri-tert-butyl phosphine are placed in a reactor together, and after being dried under vacuum, toluene is added as a solution, and the mixture is heated under reflux under argon protection for stirring reaction. After the reaction is completed, the product is extracted with water and washed with water, and then passed through a silica gel column and chromatographically separated and purified using a mixed eluent consisting of petroleum ether and dichloromethane to obtain a light green solid of the organic photogenerated free radical compound having a structure of formula II, wherein:

[0034] The molar ratio of the reactants is: dihydrophenazine: R 1 -bromide: palladium acetate: sodium tert-butoxide: tri-tert-butylphosphine = 1: (1.8-2.0): (0.030-0.038): (2.8-3.2): (0.020-0.025);

[0035] The volume ratio of the mixed eluent is: petroleum ether: dichloromethane = 10:1.

[0036] Furthermore, the preparation method of the organic photogenerated free radical compound having the structure of formula III is as follows:

[0037] Phenothiazine, R 1 -bromide, palladium acetate, sodium tert-butyl alcohol, and tri-tert-butyl phosphine are placed in a reactor together, and after being dried under vacuum, toluene is added as a solution, and the mixture is heated under reflux under argon protection for stirring reaction. After the reaction is completed, the product is extracted with water and washed with water, and then passed through a silica gel column and chromatographically separated and purified using a mixed eluent consisting of petroleum ether and dichloromethane to obtain a light green solid of the organic photogenerated free radical compound having a structure of formula III, wherein:

[0038] The molar ratio of the reactants is: phenothiazine: R 1 -bromide: palladium acetate: sodium tert-butoxide: tri-tert-butylphosphine = 1: (1.8-3.0): (0.050-0.060): (4.8-5.2): (0.020-0.025);

[0039] The volume ratio of the mixed eluent is: petroleum ether: dichloromethane = 10:1.

[0040] Furthermore, the preparation method of the organic photogenerated free radical compound having the structure of Formula IV is as follows:

[0041] N,N-diphenylphenanthrene-9,10-diamine and R 2 -compound and alkaline catalyst are placed in an organic solvent, stirred for reaction, and after the reaction is completed, the organic photogenerated free radical compound having a structure of formula IV is obtained, wherein:

[0042] The molar ratio of the reactants is:

[0043] N,N-Diphenylphenanthrene-9,10-diamine: R 2 -Compound: basic catalyst = 1: (1.0-1.2): (0.22-0.25);

[0044] The alkaline catalyst is a mixture of sodium hydride or potassium carbonate and copper sulfate.

[0045] Optionally, the silica gel column is filled with 200-300 mesh silica gel.

[0046] In addition, the present invention also provides an application of the above-mentioned photoinduced long afterglow polymer.

[0047] The application is to make the above-mentioned photoluminescent long afterglow polymer into a photoluminescent product of a required shape, or to coat or print it on products that need information encryption, information decryption, and anti-counterfeiting. After being activated by ultraviolet light irradiation, it can emit afterglow to display image information; or

[0048] Coat the above-mentioned photoluminescent long afterglow polymer on a chip substrate as a two-photon engraving marker.

[0049] Compared with the prior art, the beneficial effects and significant progress of the present invention are as follows:

[0050] 1) The photoluminescent long afterglow polymer provided by the present invention is obtained by mixing and curing an epoxy resin monomer and an organic photogenerated free radical compound. Among them, the epoxy resin serves as its main polymer, providing a rigid matrix for the organic photogenerated free radical guest small molecules, thereby inhibiting their non-radiative deactivation. Since the organic free radical photoluminescent long afterglow guest small molecules are phenazine or phenothiazine-substituted compounds, and their redox centers are located on the phenazine or phenothiazine nuclei, free radical cations can be generated after ultraviolet light irradiation, and further undergo charge transfer to recombine with the carbonyl groups on the main polymer chain to form a new species of photoluminescent long afterglow free radicals that can produce stable long afterglow. Moreover, the presence of the rigid epoxy resin matrix promotes the stable light emission of this organic photoluminescent long afterglow free radical species, providing new ideas and methods for the preparation of photoluminescent long afterglow materials;

[0051] 2) The photoluminescent long afterglow polymer provided by the present invention can achieve the purpose of regulating different luminescence phenomena by adjusting the substituents in the doped organic photogenerated free radical molecules, providing further improved ideas and methods for the preparation of photoluminescent long afterglow materials with different luminescence phenomena. At the same time, it provides new materials and new choices for the preparation of photoluminescent afterglow products for different purposes, as well as for the applications in products such as information encryption, information decryption, and anti-counterfeiting, and for lithography in chip manufacturing;

[0052] 3) The preparation method of the photoluminescent long afterglow polymer provided by the present invention is simple, the raw materials are easily available at low cost, it is easy to industrialize production, has a high yield, good economy, is environmentally friendly, has excellent application prospects and a broad market, and therefore has great promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] To more clearly illustrate the technical solutions of the present invention and the technical effects of implementing the present invention, the following briefly introduces the drawings used in the embodiments of the present invention.

[0054] Obviously:

[0055] The accompanying drawings in the following description are only the drawings of some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, but these other drawings also fall within the scope of the drawings required for the embodiments of the present invention; wherein:

[0056] Figure 1 is the fluorescence emission spectrum and low-temperature phosphorescence emission spectrum of the organic photo-generated radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) with a concentration of 5×10 -5 M in a 4-methyltetrahydrofuran solution, where the abscissa is the wavelength and the ordinate is the normalized intensity of the emitted light;

[0057] Figure 2 is the fluorescence emission spectrum and low-temperature phosphorescence emission spectrum of the organic photo-generated radical compound 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) with a concentration of 5×10 -5 M in a 4-methyltetrahydrofuran solution, where the abscissa is the wavelength and the ordinate is the normalized intensity of the emitted light;

[0058] Figure 3 is the fluorescence emission spectrum and phosphorescence (afterglow) emission spectrum of the organic photo-generated radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) doped in an epoxy resin monomer to form a photoluminescent afterglow polymer and activated by ultraviolet light, where the abscissa is the wavelength and the ordinate is the normalized intensity of the emitted light;

[0059] Figure 4 is the fluorescence emission spectrum and phosphorescence (afterglow) emission spectrum of the organic photo-generated radical compound 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) doped in an epoxy resin monomer to form a photoluminescent afterglow polymer and activated by ultraviolet light, where the abscissa is the wavelength and the ordinate is the normalized intensity of the emitted light;

[0060] Figure 5 is a photo showing the photophysical behavior of the organic photo-generated radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) doped in an epoxy resin monomer to form a photoluminescent afterglow polymer before and after activation by ultraviolet light. Among them, a) is a fluorescence photo of the photoluminescent afterglow polymer before activation by ultraviolet light, b) is a non-luminescent photo of the photoluminescent afterglow polymer after turning off the ultraviolet light before activation, and c) is a photo showing the afterglow of the photoluminescent afterglow polymer after turning off the ultraviolet light after activation;

[0061] Figure 6These are the afterglow image photos of the organic photo-generated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) doped in an epoxy resin monomer before and after being activated by ultraviolet light to form a persistent phosphorescent polymer image product. Among them, d) is the image photo of the product before being activated by ultraviolet light, and e) is the image display photo of the product after being activated by ultraviolet light;

[0062] Figure 7 These are the absorption spectra of the persistent phosphorescent polymer prepared by doping the organic photo-generated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) in an epoxy resin monomer before and after being activated by ultraviolet light and after heating. Among them, the abscissa is the wavelength, and the ordinate is the absorbance normalization intensity of the persistent phosphorescent polymer;

[0063] Figure 8 These are the graphs of the concentration changes of free radicals in the persistent phosphorescent polymer prepared by doping the organic photo-generated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) in an epoxy resin monomer over time after being activated by ultraviolet light during electron paramagnetic resonance (English: electron paramagnetic resonance, English abbreviation: EPR). Among them, the abscissa is the magnetic induction intensity, represented by the symbol B, with the unit of gauss, and the ordinate is the EPR intensity. Detailed implementation manners

[0064] To make the objectives, technical solutions, beneficial effects, and significant improvements of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the reaction formulas provided in the embodiments of the present invention. Obviously, all these described embodiments are only partial embodiments of the present invention, rather than all embodiments;

[0065] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0066] It should be noted that:

[0067] The terms "firstly", "secondly", etc. in the description, claims, and accompanying drawings of the present invention are only used to distinguish different objects, rather than to describe a specific order. In addition, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or units inherent to these processes, methods, products, or devices.

[0068] It should be understood that:

[0069] In the description of the embodiments of the present invention, some basic operation terms commonly used in the art are used, such as "heating", "stirring", "mixing", "dissolving", "washing with water", "filtering", and "drying", etc. For these terms, a broad understanding should be made. It can be the conventional operations carried out by various conventional equipment and instruments in the art, or can be operations such as programmed operations and unmanned automatic operations carried out by the latest equipment. Unless otherwise clearly defined, those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations and achieve their operation purposes by adopting specific operation methods.

[0070] It should also be noted that:

[0071] The following specific embodiments can be combined with each other. For the same or similar concepts or processes, they may not be repeated in some embodiments. In addition, the raw and auxiliary materials, reaction equipment, and facilities involved in the following specific embodiments are all commercially available.

[0072] Next, the technical solution of the present invention will be described in detail with specific embodiments.

[0073] Example 1

[0074] This example provides a photoluminescent polymer with long afterglow.

[0075] The photoluminescent polymer with long afterglow provided in this example is a doped polymer obtained by mixing and curing an epoxy resin monomer and an organic photo-generated free radical compound, where:

[0076] The epoxy resin monomer has a chemical structure shown in Formula I:

[0077] The organic photo-generated free radical compound is any one or more of the compounds with the structures shown in Formula II, Formula III, or Formula IV:

[0078] And

[0079] R 1 is the following R 11～19 shown structural group:

[0080]

[0081] R 2 is the following R 21～28 shown atom or group:

[0082]

[0083] Furthermore:

[0084] In the persistent-photoluminescence polymer provided by this embodiment, the mass of the organic photo-generated free radical compound is 0.05-10% of the mass of the epoxy resin monomer.

[0085] It can be seen from the above structure that:

[0086] First of all, the persistent-photoluminescence polymer provided by this embodiment is obtained by mixing and curing an epoxy resin monomer and an organic photo-generated free radical compound. Among them, the epoxy resin is the main polymer, which can provide a rigid matrix for the organic photo-generated free radical guest small molecules and inhibit their non-radiative deactivation;

[0087] And a phenazine or phenothiazine-substituted compound is used as the organic photo-generated free radical guest small molecule in the persistent-photoluminescence polymer. Its redox center is located on the phenazine or phenothiazine nucleus. After being irradiated by ultraviolet light, it can generate radical cations, and further form a new persistent-photoluminescence free radical species that can produce stable persistent luminescence through electron transfer and recombination with the carbonyl groups on the main polymer chain. Moreover, the presence of the rigid epoxy resin matrix can also promote the stable light emission of this organic persistent-photoluminescence free radical substance;

[0088] Due to the instability of free radicals, it is very difficult for related substances to exhibit long luminescence behavior at room temperature. Therefore, there are few reports on obtaining persistent-photoluminescence free radical materials by this mechanism. Therefore, this embodiment stabilizes free radicals by introducing a rigid polymer matrix, thereby obtaining a brand-new persistent-photoluminescence polymer, providing new ideas and methods for the preparation of persistent-photoluminescence materials, and having pioneering significance;

[0089] In addition, the persistent-photoluminescence polymer provided by this embodiment can regulate different luminescence colors and times by adjusting the substituents in the doped organic photo-generated free radical molecules, thereby providing further improved ideas and methods for the preparation of persistent-photoluminescence materials with different luminescence phenomena. At the same time, it provides new materials and new choices for the preparation of persistent-photoluminescence products for different purposes, as well as their applications in information encryption, information decryption, anti-counterfeiting and other products, and the lithography process during chip manufacturing.

[0090] Example 2

[0091] This embodiment provides a preparation method of the persistent-photoluminescence polymer described in Example 1.

[0092] The preparation method of the persistent-photoluminescence polymer provided by this embodiment includes the following steps:

[0093] Take the epoxy resin monomer with structure Ⅰ described in Example 1 and place it in a container, and stir evenly at room temperature;

[0094] Take any one or more of the organic photo-generated free radical compounds having the structures shown in Formula II, Formula III or Formula IV and add them to the above container, and mix them with the epoxy resin monomer at room temperature and stir evenly to obtain a mixed slurry;

[0095] Remove the bubbles in the mixed slurry, and then pour the mixed slurry into a mold or coat and print it on other objects, and then heat and cure it by the gradient heating method. After the curing is completed and it is cooled, the product of the photoluminescent polymer having the shape of the mold can be taken out from the mold, or other objects coated and printed with the photoluminescent polymer into an image can be obtained.

[0096] In the above preparation process, optionally, the centrifugal defoaming method is used to remove the bubbles in the mixed slurry, that is:

[0097] Place the mixed slurry in a centrifuge tube, and then place the centrifuge tube containing the mixed slurry in a centrifuge for centrifugation operation to remove the bubbles in the mixed slurry.

[0098] Further, in the above preparation process, the gradient heating method can be carried out according to the following operating procedure:

[0099] Place the mold containing the mixed slurry or other objects coated and printed with the photoluminescent polymer into an image in a heater, then raise the temperature to 80 °C and keep it warm for 2 hours, then raise the temperature to 100 °C and keep it warm for 2 hours, and then raise the temperature in batches to 120 °C, 140 °C and 160 °C in this way, and keep it warm for 2 hours after each temperature rise.

[0100] Specifically, this embodiment also provides the following preparation cases of epoxy resin monomers and some organic photo-generated free radical compounds.

[0101] Case 1. Preparation of epoxy resin monomer:

[0102] Reaction formula:

[0103] That is:

[0104] The epoxy resin monomer (I) is prepared by stirring and reacting 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (chemical abstracts database CAS registration number is 4221, abbreviated as: 4221) with 4-methylhexahydrophthalic anhydride (English: 4-methyl hexahydrophthalic anhydride, abbreviated as: MHHPA) at room temperature.

[0105] Further, in the above preparation method of the epoxy resin monomer, a catalyst is also included. Among them, the available catalyst is tetrabutylammonium bromide, and in the above reaction, the reactants have the following molar ratios:

[0106] 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate: 4-methylhexahydrophthalic anhydride: tetra-tert-butylammonium bromide = 1: (1.70-1.80): (0.090-0.095).

[0107] Specifically, you can do the following:

[0108] Weigh 5 g of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (4221), 5.87 g of 4-methylhexahydrophthalic anhydride (MHHPA) and 0.0587 g of tetra-tert-butylammonium bromide, add them into a 50 mL dry and clean beaker respectively, then add a magnetic stirrer to stir and mix them evenly, and you can get the compound of epoxy resin monomer, that is, the epoxy resin before curing.

[0109] It should be noted that:

[0110] By preparing the reactants within the above-mentioned molar ratio and using the above-mentioned specific operation methods and steps, the desired epoxy resin monomer compound can be obtained. Therefore, for the sake of brevity, this specification will not repeat them one by one.

[0111] Furthermore, this embodiment also provides a method for preparing an organic photogenerated free radical compound having a structure of Formula II, namely:

[0112] Dihydrophenazine, R 1 -bromide, palladium acetate, sodium tert-butyl alcohol, and tri-tert-butyl phosphine are placed in a reactor together, and after being dried under vacuum, toluene is added as a solution, and heated under reflux under argon protection for stirring reaction. After the reaction is completed, the product is extracted with water and washed with water, and then passed through a silica gel column and chromatographically separated and purified with a mixed eluent consisting of petroleum ether and dichloromethane to obtain a light green solid organic photogenerated free radical compound having a structure of formula II, wherein:

[0113] The molar ratio of the reactants is:

[0114] Dihydrophenazine: R 1 -bromide: palladium acetate: sodium tert-butoxide: tri-tert-butylphosphine = 1: (1.8-2.0): (0.030-0.038): (2.8-3.2): (0.020-0.025);

[0115] The volume ratio of the mixed eluent is: petroleum ether: dichloromethane = 10:1.

[0116] To further help understand the preparation scheme of the organic photogenerated free radical compound having the structure of Formula II provided in this embodiment, as well as the specific operation process and the effects that can be obtained, the following Case 2 and Case 3 are further described below.

[0117] Case 2: Preparation of organic photogenerated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (abbreviated as DPP), wherein:

[0118] The reaction formula is:

[0119] The specific operations are:

[0120] 2.5 g, i.e. 13.7 mmol, of dihydrophenazine, 4.3 g, i.e. 27.3 mmol, of bromobenzene, 0.123 g, i.e. 0.5 mmol, of palladium acetate, 3.96 g, i.e. 41.2 mmol, of sodium tert-butoxide, and 0.083 g, i.e. 0.41 mmol, of tri-tert-butylphosphine were placed in a 250 mL reaction bottle, and vacuum dried for 0.5 hour, and then 80 mL of redistilled toluene was added as a solvent, and then heated to reflux under argon protection, and stirred for reaction for 12 hours. After the reaction was completed, the mixture was extracted with water and then washed with water, and the obtained silica gel column was filled with 200-300 mesh silica gel for chromatography, elution, separation and purification, wherein the eluent was a mixed solvent of petroleum ether: dichloromethane = 10:1, and after removing the mixed solvent, 3.89 g of light green solid, namely 5,10-diphenyl-5,10-dihydrophenazine (DPP) organic photogenerated free radical compound, has a molar yield of 85% relative to dihydrophenazine.

[0121] The test results are:

[0122] 1 H NMR (400 MHz, C 6 D 6 )δ7.16(could not be resolved from NMR solventpeak), δ7.04(tt,J=5.0,3.4 Hz,2H),6.27(dd,J=5.8,3.4 Hz,4H),5.82(dd,J=5.8,3.5Hz,4H);

[0123] 13 C NMR (C 6 D 6 ,100 MHz): δ112.69,121.03,127.69,131.03,131.22,136.75,140.38;

[0124] Mass Spectrometry HRMS(ESI):calc'd for M+C 24 H 18 N 2 ,334.1470; found 334.1482.

[0125] Case 3: Preparation of organic photogenerated free radical compound 5,10-diphenyl-5,10-dimethoxyphenazine (abbreviated as DPP-OMe), wherein:

[0126] The reaction formula is:

[0127] The specific operations are:

[0128] Weigh 1 g, i.e. 5.49 mmol, of dihydrophenazine, 3.08 g, i.e. 16.47 mmol, of p-bromoanisole, 0.07 g, i.e. 0.31 mmol, of palladium acetate, 2.64 g, i.e. 27.47 mmol, of sodium tert-butoxide, and 0.24 g, i.e. 1.19 mmol, of tri-tert-butylphosphine in a 100 mL reaction bottle, and dry under vacuum for 0.5 hour. Then, add 80 mL of redistilled toluene as a solvent, heat under reflux under argon protection, and stir for 5 minutes. The reaction mixture was stirred for 12 hours. After the reaction was completed, the mixture was extracted with water and then washed with water. A silica gel column was filled with 200-300 mesh silica gel for chromatographic elution, separation and purification. The eluent was a mixed solvent of petroleum ether: dichloromethane = 10:1. After removing the mixed solvent, 1.95 g of a light green solid was obtained, namely 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) organic photogenerated free radical compound. The molar yield was 90% relative to dihydrophenazine.

[0129] The test results are:

[0130] 1 H NMR (400 MHz, C 6 D 6 )δ7.09(d,J=8.6Hz,4H),6.79-6.73(m,4H),6.35(dt,J=7.4,3.7Hz,4H),5.91(dt,J=7.6,3.8Hz,4H),3.25(s,6H);

[0131] 13 C NMR (C 6 D 6 ,100MHz): δ54.53,112.60,116.33,120.94,127.52,132.18,137.24,159.05;

[0132] Mass Spectrometry HRMS(ESI):calc'd for M+C 26 H 22 N 2 O 2 ,394.1681; found 394.1675.

[0133] It should be noted that:

[0134] First, although in the above-mentioned Case 2 and Case 3, only one reactant ratio is provided for the preparation method of the organic photogenerated free radical compound DPP and DPP-OMe, as well as the specific operation process and the detection data of the related products, however, in fact, for the preparation process satisfying the reactant molar ratio described in the preparation method of the organic photogenerated free radical compound having the structure of Formula II, as long as the molar ratio of the reactants is within the above ratio, the same product can be obtained, but the respective molar yields are different. Therefore, for the sake of brevity, this specification will not be repeated one by one;

[0135] Secondly, although Case 2 and Case 3 only provide the preparation methods and operation processes of two organic photogenerated free radical compounds, DPP and DPP-OMe, and the test data of related products, in fact, for phenazine and R 1 -bromide as the basic reactant, and the molar ratio of the relevant reactants is within the ratio of the above-mentioned reactant molar ratio, then, by operating in the same manner as in the above-mentioned case 2 or case 3, a compound having a parent core structure of formula II and a substituent R 1 R 11～19 Any one of the structural groups shown is an organic photogenerated free radical compound, and these compounds have similar photophysical properties to DPP and DPP-OMe. Therefore, for the sake of brevity, this specification will not describe them one by one.

[0136] Furthermore, this embodiment also provides a method for preparing an organic photogenerated free radical compound having a structure of Formula III, namely:

[0137] Phenothiazine, R 1 -bromide, palladium acetate, sodium tert-butyl alcohol, and tri-tert-butyl phosphine are placed in a reactor together, and after being dried under vacuum, toluene is added as a solution, and heated under reflux under argon protection for stirring reaction. After the reaction is completed, the product is extracted with water and washed with water, and then passed through a silica gel column and chromatographically separated and purified using a mixed eluent consisting of petroleum ether and dichloromethane to obtain a light green solid organic photogenerated free radical compound having a structure of formula III; wherein:

[0138] The molar ratio of the reactants is:

[0139] Phenothiazine: R 1 -bromide: palladium acetate: sodium tert-butoxide: tri-tert-butylphosphine = 1: (1.8-3.0): (0.050-0.060): (4.8-5.2): (0.020-0.025);

[0140] The volume ratio of the mixed eluent is: petroleum ether: dichloromethane = 10:1.

[0141] To further help understand the preparation scheme of the organic photogenerated free radical compound having the structure of Formula III provided in this embodiment, as well as the specific operation process and the effects that can be obtained, the following case 4 is further described below.

[0142] Case 4: Preparation of an organic photogenerated free radical compound 10-(4-methoxyphenyl)-10-hydrogen-phenothiazine, wherein:

[0143] The reaction formula is:

[0144] The specific operations are:

[0145] Weigh 1g, i.e. 5.49mmol, of phenothiazine, 1.7g, i.e. 16.47mmol, of p-bromoanisole, 0.07g, i.e. 0.31mmol, of palladium acetate, 2.64g, i.e. 27.47mmol, of sodium tert-butoxide, and 0.24g, i.e. 1.19mmol, of tri-tert-butylphosphine, and place them together in a 100mL reaction bottle, vacuum dry for 0.5 hour, then add 30mL of toluene solution after redistillation as solvent, stir and heat under reflux under argon protection, and react for 12 hours. After the reaction is completed, extract with water and wash with water, and fill the obtained silica gel column with 200-300 mesh silica gel for chromatography, elution, separation and purification, wherein the eluent is petroleum ether: dichloromethane = 10: 1, and after removing the solvent from the eluent, 1.95g of light green solid, i.e. 10-(4-methoxyphenyl)-10 hydrogen-phenothiazine organic photogenerated free radical compound, is obtained, and its molar yield is 90% relative to phenothiazine.

[0146] The test results are:

[0147] 1 H NMR (400MHz, DMSO) δ7.36–7.31(m,2H),7.23–7.17(m,2H),7.03(dd,J=7.4,1.6Hz,2H),6.90(dd d,J=8.2,7.3,1.7Hz,2H), 6.82(td,J=7.4,1.3Hz,2H), 6.13(dd,J=8.2,1.3Hz,2H), 3.85(s,3H);

[0148] 13 C NMR (101MHz, DMSO): δ159.42,144.51,132.92,132.42,127.72,127.01,122.93,119.18,116.64,116.02,55.89;

[0149] Mass Spectrometry HRMS(ESI):calc'd for M+C 19 H 16NSO, 306.0947; found 306.0895.

[0150] It should be noted that:

[0151] First of all, although in the above-mentioned Case 4, only a method and process for preparing the organic photo-generated free radical compound 10-(4-methoxyphenyl)-10H-phenothiazine with a specific reactant ratio and the detection data of its related products are given. However, in fact, for the preparation process of the organic photo-generated free radical compound with the structure of Formula III satisfying the above-mentioned reactant molar ratio, as long as the molar ratio of its reactants is within the above-mentioned ratio range, the same product can be obtained, only their respective molar yields are different. Therefore, for the sake of simplicity, this specification will not elaborate one by one.

[0152] Secondly, although Case 4 only gives the preparation method, process and the detection data of its related products of such an organic photo-generated free radical compound as 10-(4-methoxyphenyl)-10H-phenothiazine. However, in fact, for the preparation method using phenothiazine and R 1 -bromide as the basic reactants and the molar ratio of the related reactants being within the above-mentioned reactant molar ratio range, then, operating according to the same method as in Case 4, organic photo-generated free radical compounds with a parent nucleus of the structure of Formula III and any one of the substituent R 1 being R 11～19 shown in the structural group can be obtained, and these compounds all have photophysical properties similar to those of 10-(4-methoxyphenyl)-10H-phenothiazine. Therefore, for the sake of simplicity, this specification will not elaborate one by one either.

[0153] Furthermore, this embodiment also provides a preparation method of an organic photo-generated free radical compound with the structure of Formula IV, that is:

[0154] Put N,N-diphenylphenanthrene-9,10-diamine together with R 2 -compound and a basic catalyst in an organic solvent, and stir and react to obtain the organic photo-generated free radical compound with the structure of Formula IV, where:

[0155] The molar ratio of the reactants is:

[0156] N,N-diphenylphenanthrene-9,10-diamine∶R 2 -compound∶basic catalyst = 1∶(1.0 - 1.2)∶(0.22 - 0.25);

[0157] The basic catalyst is sodium hydride or a mixture of potassium carbonate and copper sulfate.

[0158] To further assist in understanding the technical solutions provided by the embodiments of the present invention, as well as the specific operation process and achievable effects of the embodiments of the present invention, hereinafter, the preparation method will be further described through the following specific cases.

[0159] Case 5. Preparation of the organic photogenerated radical compound 9,14-diphenyl-9,14-dihydrobenzophenazine, wherein:

[0160] The reaction formula is:

[0161] The specific operation is as follows:

[0162] Mix 3.60 g (i.e., 0.01 mol) of N,N-diphenylphenanthrene-9,10-diamine, 4.14 g (i.e., 0.03 mol) of potassium carbonate, 0.4 g (i.e., 2.5 mmol) of copper sulfate, 18 g (i.e., 11 mol) of trichlorobenzene, and 2.04 g (i.e., 0.01 mol) of iodobenzene, and react at 180 °C for 24 hours. After the reaction is completed, chromatographic elution separation and purification are carried out using a silica gel column filled with 200-300 mesh silica gel. Among them, the eluent ratio is:

[0163] Petroleum ether ∶ dichloromethane = 2 ∶ 1;

[0164] After the elution and purification are completed, remove the solvent from the obtained eluate to obtain 2.9 g of 9,14-diphenyl-9,14-dihydrobenzophenazine compound. The molar yield relative to N,N-diphenylphenanthrene-9,10-diamine is 67%.

[0165] The test results are as follows:

[0166] 1 H NMR (400 MHz, CDCl 3 ) δ 8.74 (d, J = 8.0 Hz, 2H), 8.12 (d, J = 8.0 Hz, 2H), 7.74 - 7.76 (m, 2H), 7.63 - 7.67 (m, 2H), 7.52 - 7.56 (m, 2H), 7.33 - 7.35 (m, 2H), 6.96 - 7.04 (m, 8H), 6.76 - 6.80 (m, 2H);

[0167] 13 C NMR (100 MHz, CDCl 3 ): δ 147.69, 144.83, 138.13, 129.88, 129.48, 128.76, 127.39, 126.98, 126.51, 125.37, 124.61, 123.02, 121.02, 116.76;

[0168] High-resolution mass spectrometry (HRMS) (ESI): calculated for M + C 32 H 23 N 2 , 435.1861; found 435.1851.

[0169] Example 6. Preparation of the organic photo-generated free radical compound 11-nitro-9,14-diphenyl-9,14-dihydrobenzo[g]phenazine, wherein:

[0170] The reaction formula is:

[0171] The specific operation is as follows:

[0172] Take 2 g (i.e., 5.55 mmol) of N,N-diphenylphenanthrene-9,10-diamine, 1.32 g (i.e., 8.30 mmol) of 3,4-difluoronitrobenzene, and 0.54 g (i.e., 22.50 mmol) of sodium hydride, and place them together in a dimethylformamide solution. React for 3 hours. After the reaction is completed, pour it into water, filter, dissolve the obtained solid in dichloromethane solution, wash it with water and saturated brine multiple times, remove water with anhydrous sodium sulfate, and then distill off the liquid under reduced pressure to obtain 2.2 g of an orange-red solid substance, namely 11-nitro-9,14-diphenyl-9,14-dihydrobenzo[g]phenazine. Its molar yield relative to N,N-diphenylphenanthrene-9,10-diamine is 83%.

[0173] The test results are as follows:

[0174] 1 H NMR (DMSO-d6, 400 MHz), δ: 8.94 (d, J = 7.2 Hz, 2H), 8.65 (s, 1H), 8.26 (d, J = 7.2 Hz, 1H), 8.13 (d, J = 9.2 Hz, 1H), 8.07 (d, J = 8.4 Hz, 1H), 7.93 (d, J = 7.6 Hz, 1H), 7.74–7.54 (m, 4H), 7.24–7.01 (m, 9H), 6.96–6.92 (m, 1H);

[0175] 13 C NMR (CDCl 3, 100 MHz), δ: 151.19, 147.49, 146.48, 144.56, 143.95, 136.27, 136.01, 130.29, 130.05, 129.34, 129.24, 128.82, 128.47, 127.33, 127.01, 126.84, 126.73, 124.95, 124.33, 124.30, 123.54, 123.20, 123.05, 122.61, 122.01, 121.16, 119.85, 117.90;

[0176] Mass spectrometry HRMS (ESI): calc’d for M+: C 32 H 21 N 3 O 2 , 479.1634, found: 479.1633.

[0177] It should be noted that:

[0178] First of all, although in the above-mentioned Case 5 and Case 6, only the preparation methods and processes of the organic photo-generated radical compounds 9,14-diphenyl-9,14-dihydrobenzophenazine and 11-nitro-9,14-diphenyl-9,14-dihydrobenzophenazine with a single reactant ratio and the detection data of their related products are given respectively. However, in fact, for the preparation process of the reactant molar ratio described in the preparation method of the organic photo-generated radical compound with the structure of Formula IV above, as long as the molar ratio of the reactants is within the above ratio range, the same product can be obtained, only their respective molar yields are different. Therefore, for the sake of simplicity, this specification will not elaborate one by one;

[0179] Secondly, although Case 5 and Case 6 only give the preparation methods and processes of two organic photo-generated radical compounds, namely 9,14-diphenyl-9,14-dihydrobenzophenazine and 11-nitro-9,14-diphenyl-9,14-dihydrobenzophenazine, and the detection data of their related products. However, in fact, for N,N-diphenylphenanthrene-9,10-diamine and R 2 -compounds as the basic reactants, and the molar ratio of the related reactants is within the ratio range of the above-mentioned reactant molar ratio. Then, by operating in the same method as in Case 5 or Case 6 above, products with a parent nucleus of the structure of Formula IV and substituents R 2 are respectively R 21～28an organic photo-generated free radical compound when it is any one of the structural groups shown, and these compounds all have photophysical properties similar to those of 9,14-diphenyl-9,14-dihydrobenzophenazine and 11-nitro-9,14-diphenyl-9,14-dihydrobenzophenazine. Therefore, for the sake of brevity, this specification will not elaborate on them one by one.

[0180] Case 7: The product obtained from the above Cases 1 to 6 was used to prepare a persistent afterglow polymer, which specifically included the following steps:

[0181] Weigh 8 portions of the epoxy resin monomer obtained from Case 1 above, with each portion being 5 g;

[0182] Then, according to the proportion of 0.05 - 10% of the mass of the epoxy resin monomer, weigh the organic photo-generated free radical compounds obtained from the above Cases 1 to 6 respectively, where:

[0183] 5,10-diphenyl-5,10-dihydrophenazine (DPP) is 0.1% i.e., 5 mg, 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) is also 0.1% i.e., 5 mg, 10-(4-methoxyphenyl)-10H-phenothiazine is 1% i.e., 50 mg, 11-nitro-9,14-diphenyl-9,14-dihydrobenzophenazine is 10% i.e., 500 mg, 9,14-diphenyl-9,14-dihydrobenzophenazine is 0.05% i.e., 2.5 mg; and

[0184] a mixture composed of 50 mg of 5,10-diphenyl-5,10-dihydrophenazine (DPP) and 50 mg of 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe);

[0185] a mixture composed of 50 mg of 5,10-diphenyl-5,10-dihydrophenazine (DPP) and 50 mg of 10-(4-methoxyphenyl)-10H-phenothiazine;

[0186] a mixture composed of 50 mg of 5,10-diphenyl-5,10-dihydrophenazine (DPP), 50 mg of 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe), 50 mg of 10-(4-methoxyphenyl)-10H-phenothiazine, 50 mg of 11-nitro-9,14-diphenyl-9,14-dihydrobenzophenazine, and 50 mg of 9,14-diphenyl-9,14-dihydrobenzophenazine;

[0187] Add the above-mentioned 5 single organic photo-generated free radical compounds and 3 mixed organic photo-generated free radical compounds into each portion of the epoxy resin monomers respectively to form doped mixtures, and then stir them respectively. Mix the epoxy resin monomers in each portion of the doped mixture with the added organic photo-generated free radical compounds evenly together. Then, put them into centrifuge tubes respectively for centrifugation to remove air bubbles, and then pour them into silicone molds respectively. After their respective surfaces level off, put them into an oven respectively, and then heat up. Use the gradient heating method for curing. Among them, the heating and curing process is as follows:

[0188] Heat at 80 °C for 2 hours, heat at 100 °C for 2 hours, heat at 120 °C for 2 hours, heat at 140 °C for 2 hours, and heat at 160 °C for 2 hours;

[0189] After the heating and curing process ends, cool it to room temperature, and after demolding, a photoluminescent epoxy resin polymer doped with one or more of the organic photo-generated free radical compounds having the structures shown in Formula II, Formula III or Formula IV, that is, the photoluminescent polymer of the present invention, can be obtained.

[0190] Experimental results show that the above-mentioned photoluminescent polymers can all exhibit the same or similar photophysical behaviors.

[0191] It should be noted that:

[0192] Although in the above-mentioned Case 7, a variety of photoluminescent epoxy resin polymers doped with one or more of the organic photo-generated free radical compounds having the structures shown in Formula II, Formula III or Formula IV, that is, the photoluminescent polymers of the present invention, are prepared. In fact, according to the above method, those skilled in the art can also obtain more types of photoluminescent polymers containing the organic photo-generated free radical compounds having the structures shown in Formula II, Formula III or Formula IV. And according to the similarity principle and the free radical luminescence principle, those skilled in the art can know that these photoluminescent polymers have the same or similar photophysical behaviors as the above-prepared long afterglow polymers. Therefore, for the sake of brevity, this specification will not elaborate further.

[0193] In addition, from the above description, it can also be seen that:

[0194] The photoluminescent polymer provided by the above cases in this embodiment has a simple preparation method, easily available raw materials, low cost, is easy to industrialize, has a high yield, good economy, is environmentally friendly, has excellent application prospects and a broad market. Therefore, it has great value for popularization and application.

[0195] Example 3

[0196] This embodiment provides an application of the photoluminescent polymer described in Example 1.

[0197] The application in this embodiment is to make the persistent-photoluminescence polymer in the above Embodiment 1 into a persistent-photoluminescence product in a required shape, or coat or print it on products that need information encryption, information decryption, and anti-counterfeiting. After being activated by ultraviolet light irradiation, it can emit persistent luminescence to display image information; or

[0198] The application in this embodiment is to coat the persistent-photoluminescence polymer in the above Embodiment 1 on a chip substrate as a two-photon engraving marker.

[0199] From the above description, it can be seen that:

[0200] The persistent-photoluminescence polymer provided in this embodiment can have various uses. It is a brand-new persistent-photoluminescence polymer, which has pioneering significance and provides new materials and new choices for the preparation of persistent-photoluminescence products for different uses, as well as the application of products in information encryption, information decryption, anti-counterfeiting, etc., and the chip manufacturing process.

[0201] Effect Examples

[0202] The following effect examples are described by taking the organic photogenerated radical compounds 5,10-diphenyl-5,10-dihydrophenazine (DPP) and 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) as examples.

[0203] It should be noted that:

[0204] Although the following effect examples only describe the photophysical properties such as the persistent luminescence of DPP and DPP-OMe, those skilled in the art should clearly understand that according to the similarity principle and the free radical luminescence principle, the other organic photogenerated radical compounds containing the structures shown in Formula II, Formula III or Formula IV provided in the embodiments of this specification and the persistent-photoluminescence polymers jointly made with epoxy resin monomers have the same or similar photophysical behaviors and the same or similar functions. Therefore, for the sake of simplicity, this specification will not elaborate further.

[0205] Next, the technical effects of the persistent-photoluminescence polymer provided in this embodiment will be described with reference to the accompanying drawings.

[0206] From Figure 1 The fluorescence emission spectrum and low-temperature phosphorescence emission spectrum of the organic photogenerated radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) with a concentration of 5×10 -5 M in a 4-methyltetrahydrofuran solution, Figure 2 The fluorescence emission spectrum and low-temperature phosphorescence emission spectrum of the organic photogenerated radical compound 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) with a concentration of 5×10 -5 M in a 4-methyltetrahydrofuran solution, it can be seen that:

[0207] Both the organic photogenerated radical compounds DPP and DPP-OMe provided in this embodiment can emit fluorescence and phosphorescence. This is because the organic photogenerated radical compounds provided in this embodiment all have an electron donor and an electron acceptor, and when the electrons are excited, they will transfer from the donor to the acceptor to form a charge transfer state. When the electrons fall back from the excited state to the ground state, they will release their energy in the form of fluorescence or phosphorescence.

[0208] From Figure 3 The fluorescence emission spectrum and phosphorescence (afterglow) emission spectrum of the organic photogenerated radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) doped in an epoxy resin monomer to form a photoluminescent afterglow polymer and activated by ultraviolet light, Figure 4 It can be seen from the fluorescence emission spectrum and phosphorescence (afterglow) emission spectrum of the organic photogenerated radical compound 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) doped in an epoxy resin monomer to form a photoluminescent afterglow polymer and activated by ultraviolet light that:

[0209] Since the photoluminescent afterglow polymer provided in this embodiment is a doped polymer obtained by mixing and curing an epoxy resin monomer and an organic photogenerated radical compound, where the doped guest molecule, i.e., the organic photogenerated radical compound such as DPP and DPP-OMe, can generate stable radical cations, and the polymer matrix, i.e., the epoxy resin monomer, can provide a rigid environment to stabilize such cations. Therefore, the photoluminescent afterglow polymer provided in this embodiment is irradiated with ultraviolet light and as the electrons generated by the light gradually increase, they will slowly accumulate in the polymer, and then combine with the radical cations to form an excited state of the guest molecule, and then return to the ground state through radiation, thus generating long luminescence, i.e., the afterglow phenomenon.

[0210] In addition, from Figure 3 it can also be seen that:

[0211] The photoluminescent afterglow polymer doped with the organic photogenerated radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) shows blue fluorescence emission under ultraviolet light irradiation at first; when the ultraviolet light is turned off, there is no delayed luminescence phenomenon; and when the photoluminescent afterglow polymer is continuously irradiated with ultraviolet light and then the ultraviolet light is turned off, the activated area of the photoluminescent afterglow polymer shows yellow long luminescence; when irradiated with ultraviolet light again and then the ultraviolet light is turned off, the activated area shows yellow long luminescence while the unactivated area does not show the long luminescence phenomenon.

[0212] In comparison Figure 3 , Figure 4The long afterglow polymer doped with the organic photo-generated free radical compound 5,10-diphenyl-5,10-dimethoxyphenazine (DPP-OMe) exhibits similar photophysical phenomena to DPP under ultraviolet light irradiation, except that its corresponding emission curve is slightly different.

[0213] From Figure 3 , Figure 4 it can be seen that:

[0214] The long afterglow polymer provided in this embodiment solves the technical problem to be solved by the present invention, that is, it can not only generate afterglow under ultraviolet light irradiation, but also the generation of afterglow is stable. By adjusting the substituents in the doped organic photo-generated free radical molecules, the purpose of regulating different luminescence phenomena can also be achieved.

[0215] Figure 5 The following shows the photos of the photophysical behavior of the long afterglow polymer prepared by doping the organic photo-generated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) in an epoxy resin monomer before and after being activated by ultraviolet light. Among them:

[0216] a) is the fluorescence photo of the long afterglow polymer before being activated by ultraviolet light, b) is the non-luminescence photo of the long afterglow polymer after the ultraviolet light is turned off and before being activated, and c) is the afterglow photo of the long afterglow polymer after the ultraviolet light is turned off and after being activated.

[0217] From Figure 5 it can be seen that:

[0218] The long afterglow polymer doped with the organic photo-generated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) first exhibits blue fluorescence emission under ultraviolet light irradiation as shown in a); when the ultraviolet light is turned off, no delayed luminescence phenomenon occurs as shown in b); when the long afterglow polymer is continuously irradiated with ultraviolet light and then the ultraviolet light is turned off, the activated area of the long afterglow polymer shows yellow long luminescence. After irradiating with ultraviolet light again and then turning off the ultraviolet light, the activated area shows yellow long luminescence while the non-activated area does not show long luminescence phenomenon as shown in c).

[0219] Figure 6 The following are the afterglow image photos of the product with a long afterglow polymer image prepared by doping the organic photo-generated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) in an epoxy resin monomer before and after being activated by ultraviolet light. Among them, d) is the product image photo before being activated by ultraviolet light, and e) is the product image display photo after being activated by ultraviolet light;

[0220] Specifically:

[0221] A black cardboard with a hollow butterfly pattern is covered on a photoluminescent polymer made by doping an organic photogenerated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) in an epoxy resin monomer. Then, after ultraviolet excitation for a period of time, the black cardboard is removed and the ultraviolet lamp is turned off. It can be seen that only the butterfly pattern shows a long luminescence phenomenon.

[0222] Figure 6 The results shown provide ideas for the application of this kind of material in information encryption and anti-counterfeiting.

[0223] Figure 7 Shown as:

[0224] After the organic photogenerated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) is doped in an epoxy resin monomer to make a photoluminescent polymer, the absorption spectra before and after being activated by ultraviolet light and after heating are shown. Among them, the abscissa is the wavelength and the ordinate is the absorbance normalization intensity of the photoluminescent polymer.

[0225] From Figure 7 it can be seen that:

[0226] The photoluminescent polymer provided in this embodiment after activation has obvious absorption changes. Among them, obvious peak patterns appear in the 400-500 nm and 600-800 nm intervals.

[0227] The activated photoluminescent polymer is placed in an oven at 160 °C and heated for one hour, and then the absorption spectrum is tested. It is found that the new peak pattern that appears after activation disappears, and the absorption spectrum of the photoluminescent polymer after heating returns to the same as that before activation.

[0228] Figure 8 Shown is the change graph of the concentration of free radicals during electron paramagnetic resonance (English: electron paramagnetic resonance, English abbreviation: EPR) over time when the photoluminescent polymer prepared by doping the organic photogenerated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) in an epoxy resin monomer is activated by ultraviolet light. Among them, the abscissa is the magnetic induction intensity, represented by the symbol B, with the unit of gauss, and the ordinate is the EPR intensity.

[0229] The specific detection is to place the persistent-photoluminescence polymer prepared by doping the organic photogenerated free radical compound 5,10-diphenyl-5,10-dihydrophenazine (DPP) in the epoxy resin monomer into a paramagnetic tube and test the free radicals in it. After irradiating with ultraviolet light for 10 seconds, 30 seconds, 60 seconds, and 90 seconds respectively, it is detected that the concentration of free radical ions in the system increases with the increase of the irradiation time, indicating that the organic compound selected in this embodiment has the ability to generate photogenerated free radicals.

[0230] In summary, it can be seen that:

[0231] First, the persistent-photoluminescence polymer provided by the embodiment of the present invention is obtained by mixing and curing an epoxy resin monomer and an organic photogenerated free radical compound. Among them, the epoxy resin is the main polymer, providing a rigid matrix, and the organic photogenerated free radical is the guest small molecule. After being irradiated with ultraviolet light, it can generate free radical cations, and through electron transfer, it combines with the carbonyl group on the main polymer chain to form a new persistent-photoluminescence free radical species that can generate stable persistent photoluminescence, promoting the stable light emission of the organic persistent-photoluminescence free radical material.

[0232] Second, for the persistent-photoluminescence polymer provided by the present invention, by adjusting the substituents in the doped organic photogenerated free radical molecules, the purpose of regulating different luminescence phenomena can be achieved, providing further improved ideas and methods for preparing persistent-photoluminescence materials with different luminescence phenomena. At the same time, it provides new materials and new choices for preparing persistent-photoluminescence products for different uses and their applications in products such as information encryption, information decryption, anti-counterfeiting, and chip manufacturing.

[0233] Third, the preparation method of the persistent-photoluminescence polymer provided by the present invention is simple, the raw materials are easy to obtain, the cost is low, it is easy to industrialize, the yield is high, the economy is good, and it is environmentally friendly. It has excellent application prospects and a broad market. Therefore, it has great popularization and application value.

[0234] In the description process of the above specification:

[0235] The descriptions of terms such as "this embodiment", "the embodiment of the present invention", "as shown in...", "further", etc. mean that the specific features, structures, materials or characteristics described in the embodiment or example are included in at least one embodiment or example of the present invention;

[0236] In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example, and moreover, the specific features, structures, materials or characteristics described can be combined or combined in a suitable manner in any one or more embodiments or examples;

[0237] In addition, on the premise of no contradiction, those of ordinary skill in the art can combine or combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0238] Finally, it should be noted that:

[0239] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. Non-essential improvements, adjustments or replacements made by those skilled in the art according to the content of this specification all fall within the scope of protection required by the present invention.

Claims

1. A photoluminescent persistent polymer, characterized in that: The photoluminescent persistent polymer is a doped polymer obtained by mixing and curing an epoxy resin monomer and an organic photogenerated free radical compound, wherein: The epoxy resin monomer has a chemical structure shown in Formula I: The organic photogenerated free radical compound is any one or more of the compounds shown in Formula II, Formula III or Formula IV: and The R 1 is the following structural group R 11～19 shown below: The R 2 is the following R 21～28 shown atom or group:

2. The photoluminescent persistent polymer according to claim 1, characterized in that: In the photoluminescent persistent polymer, the mass of the organic photogenerated free radical compound is 0.05-10% of the mass of the epoxy resin monomer.

3. A method for preparing the photoluminescent persistent polymer according to claim 1 or 2, characterized in that it comprises the following steps: Take the epoxy resin monomer and place it in a container, and stir evenly at room temperature; Take the organic photogenerated free radical compound and add it to the above container, mix it with the epoxy resin monomer at room temperature, and stir evenly to obtain a mixed slurry; Remove the bubbles in the mixed slurry, then pour the mixed slurry into a mold or coat and print it on other objects, and then heat and cure it by gradient heating method. After the curing is completed and it is cooled, the product of the photoluminescent persistent polymer with the shape of the mold can be taken out from the mold, or other objects coated and printed with images by the photoluminescent persistent polymer can be obtained.

4. The preparation method according to claim 3, characterized in that: The centrifugal defoaming method is used to remove the bubbles in the mixed slurry, that is, the mixed slurry is placed in a centrifuge tube, and then the centrifuge tube containing the mixed slurry is placed in a centrifuge for centrifugation to remove the bubbles.

5. The preparation method according to claim 3, characterized in that, The gradient heating method is carried out according to the following operating procedure: Place the mold containing the mixed slurry or other objects coated and printed with images by the photoluminescent persistent polymer in a heater, then heat up to 80 °C and keep it warm for 2 hours, then heat up to 100 °C and keep it warm for 2 hours, and then heat up to 120 °C, 140 °C and 160 °C in batches in this way, and keep it warm for 2 hours after each heating.

6. The preparation method according to claim 3, characterized in that: The epoxy resin monomer is prepared by stirring and reacting 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 4-methylhexahydrophthalic anhydride at room temperature.

7. The preparation method according to claim 6, characterized in that, further comprising: A catalyst, the catalyst is tetrabutylammonium bromide, and the molar ratio of each reaction material is as follows: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate∶4-methylhexahydrophthalic anhydride∶tetrabutylammonium bromide = 1∶(1.70-1.80)∶(0.090-0.095).

8. The preparation method according to claim 3, characterized in that, The preparation method of the organic photogenerated free radical compound having the structure of Formula II is: Dihydrophenazine, R 1 -bromide, palladium acetate, sodium tert-butyl alcohol, and tri-tert-butyl phosphine are placed in a reactor together, and after being dried under vacuum, toluene is added as a solution, and the mixture is heated under reflux under argon protection for stirring reaction. After the reaction is completed, the product is extracted with water and washed with water, and then passed through a silica gel column and chromatographically separated and purified using a mixed eluent consisting of petroleum ether and dichloromethane to obtain a light green solid of the organic photogenerated free radical compound having a structure of formula II, wherein: The molar ratio of the reactants is: Dihydrophenazine: R 1 -bromide: palladium acetate: sodium tert-butoxide: tri-tert-butylphosphine = 1: (1.8-2.0): (0.030-0.038): (2.8-3.2): (0.020-0.025); The volume ratio of the mixed eluent is: Petroleum ether∶Dichloromethane = 10∶1.

9. The preparation method according to claim 3, characterized in that, The preparation method of the organic photo-generated free radical compound with the structure of formula III is as follows: Phenothiazine, R 1 -bromide, palladium acetate, sodium tert-butyl alcohol, and tri-tert-butyl phosphine are placed in a reactor together, and after being dried under vacuum, toluene is added as a solution, and the mixture is heated under reflux under argon protection for stirring reaction. After the reaction is completed, the product is extracted with water and washed with water, and then passed through a silica gel column and chromatographically separated and purified using a mixed eluent consisting of petroleum ether and dichloromethane to obtain a light green solid of the organic photogenerated free radical compound having a structure of formula III, wherein: The molar ratio of the reactants is: Phenothiazine∶R 1 -Bromide∶Palladium acetate∶Sodium tert-butoxide∶Tri-tert-butylphosphine = 1∶(1.8 - 3.0)∶(0.050 - 0.060)∶(4.8 - 5.2)∶(0.020 - 0.025); The volume ratio of the mixed eluent is: Petroleum ether∶Dichloromethane = 10∶1.

10. For the preparation method according to claim 3, characterized in that The preparation method of the organic photo-generated free radical compound with the structure of formula IV is as follows: Combine N,N-diphenylphenanthrene-9,10-diamine with R 2 -compound and a basic catalyst in an organic solvent, stir and react. After the reaction is completed, the organic photo-generated radical compound with the structure of Formula IV is obtained, where: The molar ratio of the reactants is: N,N-Diphenylphenanthrene-9,10-diamine∶R 2 -Compound∶Basic catalyst = 1∶(1.0 to 1.2)∶(0.22 to 0.25); The basic catalyst is sodium hydride or a mixture of potassium carbonate and copper sulfate.

11. For the preparation method according to claim 8 or 9, characterized in that: The filler of the silica gel column is silica gel with a mesh size of 200 - 300.

12. An application of the photoluminescent polymer according to claim 1 or 2, characterized in that: The application is to make the photoluminescent polymer according to claim 1 or 2 into a photoluminescent product of a required shape or coat and print it on products that need information encryption, information decryption, and anti-counterfeiting. After being activated by ultraviolet light irradiation, it can emit afterglow to display image information; or coat the photoluminescent polymer according to claim 1 or 2 on a chip substrate as a two-photon engraving marker.

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