A polymer with thermally enhanced long afterglow properties and its preparation method and application

Abstract

The present invention discloses a polymer with thermally enhanced long afterglow characteristics, as well as its preparation method and application, and belongs to the technical field of organic long afterglow polymers. The polymer of the present invention is prepared by heating and melting an electron donor organic matter and an electron acceptor organic matter. The electron donor organic matter includes a triphenylamine group, a boric acid pinacol ester group connected to the triphenylamine group, and the benzene ring connected to the boric acid pinacol ester group in the triphenylamine group is connected to at least one of the remaining benzene rings in the triphenylamine group via a carbon-carbon single bond; the electron acceptor organic matter is polyethylene terephthalate. After being irradiated with ultraviolet light or sunlight, the polymer of the present invention can generate long afterglow emission with a peak at 520 nm (green light) or 560 nm (yellow-green light), and its long afterglow intensity will increase significantly as the ambient temperature rises.

Description

Technical Field

[0001] The present invention relates to the technical field of organic long-afterglow polymers, and in particular to a polymer with thermally enhanced long-afterglow properties, a preparation method thereof, and applications thereof. Background Art

[0002] Long-lasting luminescence (LPL) is a unique photophysical phenomenon that differs from traditional transient fluorescence. Its excited-state carriers can continue to recombine upon irradiation even after excitation ceases, with luminescence durations ranging from milliseconds to hours. This time-tunable luminescence behavior has made it a cutting-edge research area. Compared to transient fluorescence, long-lasting materials effectively eliminate background fluorescence interference and improve the signal-to-noise ratio by extending the detectable luminescence signal duration. Consequently, they demonstrate significant advantages in bioluminescence imaging, multi-level anti-counterfeiting systems, and sensitive optical sensing, driving the development of new, efficient, and stable long-lasting material systems.

[0003] Inorganic long-afterglow systems based on trap engineering exhibit multi-mode optical response characteristics such as photoluminescence, long-afterglow luminescence, and photostimulated luminescence by constructing deep and shallow energy level traps. However, this type of material faces significant technical bottlenecks in practical applications: first, the high synthesis temperature limits the material's processing performance and the high preparation cost; second, the brittleness of the material itself restricts its integration into flexible devices; and third, the high content of heavy metals can easily lead to biocompatibility risks. To this end, current research is dedicated to developing new long-afterglow materials that are prepared by low-temperature solution methods, are flexible and processable, and are environmentally friendly, in order to achieve stable and reliable optical sensing applications.

[0004] Organic long-lasting glow materials, with their tunable mechanical properties, ease of low-temperature solution processing, and excellent biosafety, have shown potential as an alternative to inorganic systems. However, non-irradiative relaxation of triplet excitons induced by ambient oxygen / water can easily quench luminescence, limiting their room-temperature afterglow duration to milliseconds to seconds. Recent molecular engineering strategies, such as constructing exciplex-type donor-acceptor systems, have successfully extended the lifetime of organic afterglow to hours. However, these materials still face key challenges, including insufficient photostability and poor environmental tolerance. Some researchers have significantly improved their environmental stability by developing p-type doping systems, constructing eutectic composites, and incorporating rigid matrix structures. Notably, their thermal stability still lags significantly behind that of inorganic materials. Increasing temperature exacerbates molecular thermal motion, leading to dissipation of excited-state energy via non-irradiative pathways. Furthermore, high temperatures induce irreversible damage, such as molecular configurational distortion, isomerization, and conjugated backbone breakage, which alters the luminescent energy distribution and quenches luminescence. These factors collectively pose significant challenges to the room-temperature luminescence stability of organic long-lasting glow materials. Summary of the Invention

[0005] In order to solve the problems of poor stability and quenching of luminescence when heated in the prior art organic long afterglow materials, one of the objectives of the present invention is to provide a method for preparing a polymer with thermally enhanced long afterglow properties.

[0006] The present invention solves the above technical problems with the following technical solution: a method for preparing a polymer having thermally enhanced long afterglow characteristics is provided, the preparation method comprising the following steps:

[0007] Step 1: Grinding the electron donor organic matter and the electron acceptor organic matter with an organic solvent to obtain a mixed powder;

[0008] Step 2: heating the mixed powder to a transparent molten state and then immediately cooling to room temperature to obtain a polymer with thermally enhanced long afterglow properties;

[0009] The electron donor organic compound consists of a triphenylamine group and a boric acid pinacol ester group connected to the triphenylamine group, wherein the benzene ring in the triphenylamine group connected to the boric acid pinacol ester group is connected to at least one of the remaining benzene rings in the triphenylamine group via a carbon-carbon single bond;

[0010] The electron acceptor organic compound is polyethylene terephthalate.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows:

[0012] Furthermore, in step 1, the mass ratio of the electron donor organic matter to the electron acceptor organic matter is 0.001-0.05:1.

[0013] Furthermore, the mass of the organic solvent is 2 to 3 times the sum of the masses of the electron donor organic matter and the electron acceptor organic matter.

[0014] Furthermore, the organic solvent is ethanol.

[0015] Furthermore, the mixed powder in step 2 is heated at 270-290° C. to a transparent molten state and maintained for 5-10 minutes.

[0016] A second object of the present invention is to provide a polymer having thermally enhanced long afterglow properties prepared according to the first object.

[0017] The third object of the present invention is to provide a method for using the polymer with thermally enhanced long afterglow characteristics in the second object in temperature-responsive optical sensors, multimodal dynamic anti-counterfeiting labels and flexible optoelectronic storage devices.

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

[0019] 1. The polymer with thermally enhanced long afterglow characteristics in the present invention can produce long afterglow emission with a peak at 520 nm (green light) or 560 nm (yellow-green light) after 365 nm ultraviolet excitation, and its room temperature afterglow duration is up to 12 hours, which is significantly improved compared with the millisecond and several seconds afterglow time of traditional phosphorescent materials. In addition, the polymer in the present invention exhibits a significant thermally activated afterglow enhancement effect in the temperature range of 20-200°C, with the maximum luminous intensity reaching 56 times the initial value. Moreover, after the long afterglow of the polymer in the present invention has completely decayed, it can produce thermoluminescence through thermal stimulation.

[0020] The polymers of this invention also possess excellent chemical stability and solution processability, making them suitable for applications in temperature sensing, optical information encryption, and anti-counterfeiting. In particular, they can be processed into various shapes using 3D printing technology, facilitating integration with industrial components. When used in temperature sensing, the polymers produce significant thermoluminescence when the local temperature changes, effectively reflecting the temperature change and thus achieving temperature sensing capabilities.

[0021] 2. The present invention achieves an increase in the intensity of the long afterglow when the temperature rises mainly through the following aspects: 1) By regulating the orbital energy level and steric hindrance of the receptor unit through molecular engineering, a DA-type long afterglow system with thermal responsive characteristics is constructed; 2) The topological entanglement effect of the polymer matrix is ​​utilized to suppress the non-irradiation deactivation of excitons, thereby achieving an ultra-long afterglow of 12 hours at room temperature; 3) A planar locking strategy is adopted, that is, the benzene ring connected to the boric acid pinacol ester group is locked with other benzene rings through a carbon-carbon single bond, thereby avoiding the rotation of the benzene ring under ultraviolet light irradiation, avoiding ineffective energy loss, and also avoiding the destruction of the overall configuration of the polymer, thereby avoiding fluorescence quenching, and ultimately breaking through the limitations of the thermal quenching effect of traditional organic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram of the light-emitting principle of the polymer;

[0023] Figure 2 is the spectrum of polymer BTPA@PET;

[0024] Figure 3 is the spectrum of polymer BPCz@PET;

[0025] Figure 4 is the spectrum of polymer BICz@PET;

[0026] Figure 5 Long afterglow lifetime diagrams of polymer BTPA@PET, polymer BPCz@PET, and polymer BICz@PET;

[0027] Figure 6This is the long afterglow lifetime diagram of polymer BTPA@PET at different temperatures;

[0028] Figure 7 This is the long afterglow lifetime diagram of polymer BPCz@PET at different temperatures;

[0029] Figure 8 This is the long afterglow lifetime diagram of polymer BICz@PET at different temperatures;

[0030] Figure 9 The long afterglow lifetime diagram of polymer BICz@PET under different light sources;

[0031] Figure 10 This is the long afterglow lifetime diagram of the polymer BICz@PET after heating treatment after 100 seconds of testing;

[0032] Figure 11 Thermoluminescence spectra of polymer BTPA@PET, polymer BPCz@PET and polymer BICz@PET;

[0033] Figure 12 The absorption spectra of polymer BTPA@PET before and after irradiation with 365 nm UV light;

[0034] Figure 13 The absorption spectra of polymer BPCz@PET before and after irradiation with 365 nm UV light;

[0035] Figure 14 The absorption spectra of polymer BICz@PET before and after irradiation with 365 nm UV light;

[0036] Figure 15 A flow chart for polymer extrusion molding;

[0037] Figure 16 The thermally enhanced long afterglow photographs of the square structure prepared in Example 1 and the honeycomb structure prepared in Example 2, wherein: Figure 16 Figure ① is a thermally enhanced long afterglow photograph of the honeycomb structure prepared in Example 2. Figure 16 Figure ② is a thermally enhanced long afterglow photograph of the square structure prepared in Example 1;

[0038] Figure 17 The test results of the thermal monitoring device in a simulated real-world scenario using a honeycomb structure made of polymer BICz@PET and aluminum sheets. DETAILED DESCRIPTION

[0039] The following describes a polymer having thermally enhanced long afterglow properties, its preparation method, and its application in the present application in conjunction with embodiments. However, the present application can be exemplified in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the scope of the application to those skilled in the art.

[0040] According to the inventors' aforementioned research, organic long-afterglow materials have the problem of poor thermal stability. In the prior art, Yusheng Zhou et al. introduced benzene rings in their paper "Sunlight-Activated Hour-Long Afterglow from Transparent and Flexible Polymers" to improve the stability of the polymer. However, the long-afterglow luminescence intensity of the polymer prepared thereby gradually decreases with increasing temperature, and exhibits thermal quenching at high temperatures, thereby limiting the application of organic long-afterglow materials.

[0041] Based on this, the present invention provides a polymer whose long afterglow intensity can be increased when the temperature is increased.

[0042] An embodiment of the first aspect of the present invention provides a method for preparing a polymer having thermally enhanced long afterglow properties, comprising the following steps:

[0043] Step 1: Grinding the electron donor organic matter and the electron acceptor organic matter with an organic solvent to obtain a mixed powder;

[0044] Step 2: heating the mixed powder to a transparent molten state and then immediately cooling to room temperature to obtain a polymer with thermally enhanced long afterglow properties;

[0045] The electron donor organic compound consists of a triphenylamine group and a boric acid pinacol ester group connected to the triphenylamine group, wherein the benzene ring in the triphenylamine group connected to the boric acid pinacol ester group is connected to at least one of the remaining benzene rings in the triphenylamine group via a carbon-carbon single bond;

[0046] The electron acceptor organic material is polyethylene terephthalate (PET).

[0047] The luminescence mechanism of the polymer in the present invention is as follows Figure 1 As shown, specifically: after the polymer is irradiated by light, the electrons of the electron donor organic matter are captured by the electron acceptor organic matter molecules and move between the acceptor molecules, and finally return to the donor molecules to generate long afterglow luminescence.

[0048] The reasons why the afterglow intensity of the polymer in the present invention is enhanced when the temperature is increased are as follows: ① UV excitation induces intramolecular charge transfer (ICT) of the electron donor organic compound (hereinafter referred to as the donor unit A) to the lowest unoccupied orbital (LUMO); ② by molecular engineering to regulate the orbital energy level and steric hindrance of the electron acceptor organic compound (hereinafter referred to as the acceptor unit), a DA-type long afterglow system with thermal response characteristics is constructed, and orbital coupling at the DA interface realizes the directional migration of electrons from the A-LUMO to the LUMO of the PET matrix, forming an excited state of the exciplex; ③ the exciplex dissociates to generate free radical anions (PET ·- ) and cations (A ·+ , derived from electron donor organic matter), spatially separated by polymer chains; PET carrying excess electrons ·- *Exchanges charges with A, resulting in the generation of a large amount of A ·- *; ④ Under external thermal disturbance A ·- *An opposite charge exchange occurs with PET, resulting in PET ·- *. Finally, PET ·- * and A ·+ The recombination releases energy to produce a long afterglow. Based on this, the polymer temperature increase in the present invention can accelerate the migration and recombination efficiency of charge carriers, thereby achieving an exponential increase in the afterglow intensity.

[0049] It can be seen that the polymer in the present invention achieves the enhancement of the long afterglow intensity of the polymer when the temperature is increased based on the synergistic effect of multi-level energy transfer and thermal activation.

[0050] In addition, the electron donor organic compound in the present invention consists of two parts: a triphenylamine group and a boric acid pinacol ester group. The triphenylamine group has excellent electron donating properties, and the further introduced boric acid pinacol ester group can effectively regulate the electron donating ability of the entire molecule. In addition, the benzene ring in the triphenylamine group connected to the boric acid pinacol ester group in the present invention is connected to at least one of the remaining benzene rings in the triphenylamine group via a carbon-carbon single bond, thereby locking the benzene ring and preventing the rotation of the benzene ring under ultraviolet light irradiation (the reason is that the strong covalent bond interaction can effectively offset the rotation of the benzene ring), thereby preventing the overall structure of the electron donor organic compound from being destroyed, thereby avoiding ineffective energy loss, and ultimately achieving enhanced long-lasting glow intensity of the polymer when heated.

[0051] Preferably, the electron donor organic compound in the present invention has the structural formula: (BICz, chemical formula: C 24 H 22 BNO2) or (Name: 9-phenyl-9H-carbazole-3-boronic acid pinacol ester (BPCz), chemical formula: C 24 H 24BNO2), of course, in practice, it may also be other compounds with similar structures to the electron donor organic compounds described in the present invention.

[0052] In some embodiments, the mass ratio of the electron donor organic compound to the electron acceptor organic compound in step 1 is 0.001 to 0.05:1. In this embodiment, this mass ratio ensures that the prepared polymer has excellent long-lasting performance, thereby avoiding the situation where the mass ratio is less than 0.001:1, where the concentration of the electron donor organic compound is too low, resulting in poor long-lasting performance; and avoiding the situation where the mass ratio is greater than 0.05:1, where the concentration of the electron donor organic compound is too high, resulting in concentration quenching and also poor long-lasting performance.

[0053] In some embodiments, the mass of the organic solvent is 2-3 times the combined mass of the electron donor organic compound and the electron acceptor organic compound. This ratio ensures that the electron donor organic compound and the electron acceptor organic compound are fully mixed. Preferably, the organic compound in this embodiment can be ethanol, which has a low boiling point and readily evaporates during heating of the mixed powder without participating in the reaction.

[0054] In some embodiments, the mixed powder in step 2 is heated to 270-290°C until it becomes transparent and molten and maintained for 5-10 minutes. This temperature range does not damage the PET structure and is close to the melting point of PET, which is conducive to obtaining a polymer with thermally enhanced long afterglow properties.

[0055] The embodiment of the second aspect of the present invention provides a polymer having thermally enhanced long afterglow characteristics, and the polymer is prepared by the method described in the embodiment of the first aspect.

[0056] The embodiment of the third aspect of the present invention is to provide an application of a polymer with thermally enhanced long afterglow characteristics, and the polymer recorded in the embodiment of the second aspect is mainly used in technical fields such as temperature-responsive optical sensor devices, multimodal dynamic anti-counterfeiting labels and flexible optoelectronic storage.

[0057] Example

[0058] The technical solutions of the present invention will be further explained below through specific embodiments.

[0059] Example 1

[0060] A method for preparing a polymer having thermally enhanced long afterglow properties comprises the following steps:

[0061] Step 1. Weigh 0.004 g of BPCz (purity 99.9%) and 0.8 g of PET (purity 99.9%); then add 3 ml of ethanol and grind thoroughly in an agate mortar for 0.5 h to obtain a mixed powder;

[0062] Step 2: Place the mixed powder into a quartz mold, then place the quartz mold on a heating table at 280°C and heat for 5 minutes until the mixed powder is completely melted and becomes a transparent fluid state. Remove the quartz mold and quickly cool it to room temperature. Demold to obtain the polymer BPCz@PET with thermally enhanced long afterglow properties.

[0063] In addition, according to Figure 15 Flowchart of polymer extrusion molding: The polymer BICz@PET prepared in this example was made into a square structure by 3D printing.

[0064] Example 2

[0065] A method for preparing a polymer having thermally enhanced long afterglow properties comprises the following steps:

[0066] Step 1. Weigh 0.004 g of BICz (purity 99.9%) and 0.8 g of PET (purity 99.9%); then add 3 ml of ethanol and grind thoroughly in an agate mortar for 0.5 h to obtain a mixed powder;

[0067] Step 2: Place the mixed powder into a quartz mold, then place the quartz mold on a heating table at 280°C and heat for 10 minutes until the powder is completely melted and becomes a transparent flowable state. Remove the quartz mold and quickly cool it to room temperature. Demold to obtain the polymer BICz@PET with thermally enhanced long afterglow properties.

[0068] In addition, according to Figure 15 Flowchart of Polymer Extrusion Molding The polymer BICz@PET prepared in this example was made into a honeycomb grid structure by 3D printing.

[0069] Comparative Example 1

[0070] A method for preparing a polymer comprises the following steps:

[0071] Step 1: Weigh 0.004 g of BTPA (99.9% purity) and 0.8 g of PET (99.9% purity); then add 3 ml of ethanol and grind thoroughly in an agate mortar for 0.5 hours to obtain a mixed powder; wherein the structural formula of BTPA is: .

[0072] Step 2: Place the mixed powder into a quartz mold, then place the quartz mold on a heating table at 280°C and heat for 10 minutes until the powder is completely melted and becomes a transparent flowable state. Remove the quartz mold and quickly cool it to room temperature. Demold to obtain a polymer BTPA@PET with thermally enhanced long afterglow properties.

[0073] Test analysis:

[0074] 1. The polymers prepared in Comparative Example 1, Example 1 and Example 2 were subjected to emission spectrum, phosphorescence spectrum and long afterglow spectrum test analysis. The test results are detailed in Figure 2 、 Figure 3 and Figure 4 ;in, Figure 2 is the spectrum of polymer BTPA@PET; Figure 3 is the spectrum of polymer BPCz@PET; Figure 4 is the spectrum of polymer BICz@PET; Figure 2 、 Figure 3 and Figure 4 The PL is the emission spectrum curve, RTP is the phosphorescence spectrum curve, and LPL is the long afterglow spectrum curve.

[0075] from Figure 2 It can be seen that the fluorescence emission peak of the polymer prepared in Comparative Example 1 is at 520 nm (green light), the phosphorescence emission peak is at 520 nm (green light), and the long afterglow emission peak is at 520 nm (green light); Figure 3 It can be seen that the fluorescence emission peak of the polymer prepared in Example 1 is at 470 nm (blue-green light), the phosphorescence emission peak is at 520 nm (green light), and the long afterglow emission peak is at 520 nm (green light); Figure 4 It can be seen that the fluorescence emission peak of the polymer prepared in Example 2 is at 380 nm (blue light), the phosphorescence emission peak is at 480 nm (blue-green light), and the long afterglow emission peak is at 560 nm (yellow-green light).

[0076] 2. Polymer long afterglow life test

[0077] (1) Long afterglow lifetime test of polymers after light irradiation

[0078] The long afterglow life test results of the polymers prepared in Comparative Example 1, Example 1 and Example 2 after irradiation with 60W 365 nm ultraviolet light for 3 minutes are as follows: Figure 5 As shown, Figure 5 These are the long afterglow lifetime diagrams of polymers BTPA@PET, BPCz@PET, and BICz@PET.

[0079] from Figure 5 It can be seen that the long afterglow life of the polymer BTPA@PET prepared in Comparative Example 1 can exceed 10 4 The long afterglow lifetime of the polymer BPCz@PET prepared in Example 1 can exceed 10 4 The long afterglow lifetime of the polymer BICz@PET prepared in Example 2 can exceed 10 4 Second.

[0080] (2) Long afterglow life test of polymers at different temperatures

[0081] The polymers prepared in Comparative Example 1, Example 1 and Example 2 were placed in different temperature environments (the polymers prepared in Comparative Example 1 and Example 1 were tested in environments of 300K and 380K, and the polymer prepared in Example 2 was tested in environments of 300K, 325K, 350K, 375K and 400K) to test the afterglow lifetime of the polymers. The test results are as follows: Figure 6 、 Figure 7 and Figure 8 As shown, Figure 6 This is the long afterglow lifetime diagram of polymer BTPA@PET at different temperatures. Figure 7 The long afterglow lifetime diagram of polymer BPCz@PET at different temperatures is shown in Figure 2. Figure 8 This is the afterglow lifetime diagram of the polymer BICz@PET at different temperatures.

[0082] from Figure 6 It can be seen that the initial intensity of the afterglow of the polymer BTPA@PET prepared in Comparative Example 1 decreases as the ambient temperature increases, the afterglow life is shortened, and the afterglow performance decreases as the temperature increases. Figure 7 It can be seen that the initial intensity of the afterglow of the polymer BPCz@PET prepared in Example 1 increases with the increase of ambient temperature, while the afterglow lifetime decreases. Figure 8 It can be seen that the polymer BICz@PET prepared in Example 2 also increases in initial afterglow intensity and shortens afterglow lifetime as the ambient temperature increases.

[0083] (3) Afterglow life test of polymers after irradiation with different light sources

[0084] The polymer BICz@PET prepared in Example 2 was irradiated under different light sources (365 nm ultraviolet light, natural light, 393 nm ultraviolet light, 254 nm ultraviolet light) for 3 minutes and then the afterglow lifetime of the polymer was tested. The test results are as follows: Figure 9 As shown; Figure 9 This is the long afterglow lifetime diagram of polymer BICz@PET under different light sources.

[0085] from Figure 9 It can be seen that after being irradiated with 365 nm UV light for 3 minutes, the polymer BICz@PET exhibits the longest afterglow lifetime.

[0086] 3. The polymer BICz@PET prepared in Example 2 was subjected to a long afterglow lifetime test after being heated for 100 seconds. The heating temperatures during the test were 325 K, 350 K, 375 K, and 400 K. The test results are detailed in Figure 10 .

[0087] Figure 10 This is the long afterglow lifetime diagram of the polymer BICz@PET after heating treatment after 100 seconds of testing; Figure 10 It can be seen from the figure that the afterglow intensity of the polymer BICz@PET increases with increasing temperature.

[0088] 4. Polymer Thermo-optical Spectroscopic Analysis

[0089] The polymer BTPA@PET prepared in Comparative Example 1, the polymer BPCz@PET prepared in Example 1, and the polymer BICz@PET prepared in Example 2 were placed in an aluminum tank with a volume of 8 cubic millimeters. Thermoluminescence spectroscopy was performed under a PMT (photomultiplier tube) high voltage of 1000 volts and a heating rate of 3°C / s. The test results are shown in FIG. Figure 11 shown.

[0090] Figure 11 The thermoluminescence spectra of polymer BTPA@PET, polymer BPCz@PET and polymer BICz@PET are shown in Figure 2. Figure 11 As can be seen, the thermoluminescence peak of the polymer BTPA@PET is primarily at 425 K, belonging to the deep trap category. The thermoluminescence intensity of the BTPA@PET film is the lowest among the three, resulting in its thermoluminescence being unable to effectively compensate for thermal quenching at high temperatures, resulting in a decrease in afterglow performance. The thermoluminescence peak of the polymer BPCz@PET is primarily at 415 K, belonging to the deep trap category. The thermoluminescence intensity of the BPCz@PET film is very high, indicating a high trap concentration, which effectively compensates for thermal quenching at high temperatures, resulting in an improvement in afterglow performance. The thermoluminescence peak of the polymer BICz@PET is primarily at 435 K, belonging to the deep trap category, and the signal intensity is the highest among the three, consistent with the long afterglow lifetime. The thermoluminescence intensity of the BICz@PET film is the highest among the three, indicating the highest trap concentration, which effectively compensates for thermal quenching at high temperatures, resulting in an improvement in afterglow performance.

[0091] 5. Polymer Absorption Spectrum Analysis

[0092] The polymer BTPA@PET prepared in Comparative Example 1, the polymer BPCz@PET prepared in Example 1, and the polymer BICz@PET prepared in Example 2 were irradiated under a 60 W 365 nm ultraviolet lamp for 3 minutes and then subjected to absorption spectrum analysis. The test results are as follows: Figure 12 、 Figure 13 and Figure 14 shown.

[0093] in, Figure 12The absorption spectra of polymer BTPA@PET before and after irradiation with 365 nm UV light; Figure 13 The absorption spectra of polymer BPCz@PET before and after irradiation with 365 nm UV light; Figure 14 This is the absorption spectrum of the polymer BICz@PET before and after irradiation with 365nm ultraviolet light.

[0094] from Figure 12 It can be seen that after being irradiated with light, the absorption spectrum of the polymer BTPA@PET produces an obvious absorption band at 500~800 nm, and the new absorption band is attributed to BTPA ·+ and PET ·- The production of free radicals. Figure 13 It can be seen from the figure that after light irradiation, the absorption spectrum of the polymer BPCz@PET produces an obvious absorption band at 500~800 nm. The new absorption band is attributed to BPCz ·+ and PET ·- The production of free radicals. Figure 14 It can be seen from the figure that after being irradiated with light, the absorption spectrum of the polymer BICz@PET produces an obvious absorption band at 500~800 nm. The new absorption band is attributed to BICz ·+ and PET ·- Production of free radicals.

[0095] 6. Long afterglow test of the square structure made of polymer BPCz@PET by 3D printing and the honeycomb structure made of polymer BICz@PET by 3D printing. During the test, the square structure and the honeycomb structure were heated by a heating plate, and the long afterglow intensity at different temperatures was observed. The test results are as follows Figure 16 shown.

[0096] Figure 16 The thermally enhanced long afterglow photographs of the square structure prepared in Example 1 and the honeycomb structure prepared in Example 2, wherein: Figure 16 Figure ① is a thermally enhanced long afterglow photograph of the honeycomb structure prepared in Example 2. Figure 16 Figure ② is a thermally enhanced long afterglow photograph of the square structure prepared in Example 1. Figure 16 As can be seen from Figure ①, the honeycomb structure is formed by heating the polymer BICz@PET on the heating plate through 3D printing. As the temperature rises, the yellow-green long afterglow intensity gradually increases; Figure 16 As can be seen from Figure ②, by heating the heating plate, the square structure formed by 3D printing of the polymer BPCz@PET gradually increases with the increase of temperature.

[0097] 7. The honeycomb grid structure made by 3D printing of the polymer BICz@PET in Example 2 was subjected to a long afterglow test. During the test, the honeycomb grid structure was coated on an aluminum cylinder to form a simple thermal monitoring device. During the test, the aluminum cylinder was heated. The test results are shown in the figure. Figure 17 shown.

[0098] Figure 17 The test results of the thermal monitoring device in a simulated real-world scenario for a honeycomb structure made of polymer BICz@PET and aluminum sheet. Figure 17 It can be seen that the corresponding position of the polymer cylinder outside the aluminum cylinder shows an enhanced yellow-green long afterglow, which effectively reflects the change and distribution of temperature.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a polymer having thermally enhanced long afterglow properties, characterized in that: The following steps are involved: Step 1: Grinding the electron donor organic matter and the electron acceptor organic matter with an organic solvent to obtain a mixed powder; Step 2: heating the mixed powder to a transparent molten state and then immediately cooling it to room temperature to obtain a polymer with thermally enhanced long afterglow properties; The electron donor organic compound consists of a triphenylamine group and a boric acid pinacol ester group connected to the triphenylamine group; wherein the benzene ring connected to the boric acid pinacol ester group in the triphenylamine group is connected to at least one of the remaining benzene rings in the triphenylamine group through a carbon-carbon single bond; The electron acceptor organic matter is polyethylene terephthalate.

2. The preparation method according to claim 1, characterized in that In step 1, the mass ratio of the electron donor organic matter to the electron acceptor organic matter is 0.001-0.05:

1.

3. The preparation method according to claim 1, characterized in that The mass of the organic solvent is 2 to 3 times the sum of the mass of the electron donor organic matter and the electron acceptor organic matter.

4. The preparation method according to claim 3, characterized in that The organic solvent is ethanol.

5. The preparation method according to claim 1, characterized in that The mixed powder in step 2 is heated at 270-290° C. to a transparent molten state and maintained for 5-10 minutes.

6. A polymer having thermally enhanced long afterglow properties prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the polymer with thermally enhanced long afterglow properties as claimed in claim 6 in temperature-responsive optical sensors, multimodal dynamic anti-counterfeiting labels and flexible optoelectronic storage devices.

Images