Polyarylether polymer, electrochromic device and preparation method of polyarylether polymer

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a polyarylether polymer based on phenoxazine and derivatives thereof, an electrochromic device and a preparation method of the polyarylether polymer. By introducing a phenoxazine structure into a side chain, the polyarylether electrochromic polymer capable of changing from colorless to magenta is successfully prepared, and the polyarylether electrochromic polymer has excellent photoelectric activity and thermal stability. In order to solve the problem that varieties of electrochromic materials with the characteristic of changing from colorless to black are deficient, based on the color blending theory, the prepared polymer and another polymer are compounded in proportion, an electrochromic device capable of changing from colorless to black is successfully prepared, and the method is suitable for large-scale production and has huge economic value.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a polyarylether polymer, an electrochromic device and a preparation method thereof. Background Art

[0002] Organic polymer electrochromic materials, characterized by low driving voltage, fast switching time, and easy processing, have attracted widespread attention from researchers. In 2008, Reynolds et al. developed a π-conjugated polymer-based black electrochromic material using a donor-acceptor approach. While these conjugated polymers exhibit excellent electrochromic performance, they can only achieve a transition from black to transparent, requiring energy to maintain the transparent state when used in smart windows or automotive windows. Furthermore, the high cost of π-conjugated polymers has limited their large-scale commercialization. Therefore, the development of low-cost, high-performance, colorless-to-black electrochromic polymer materials is of great significance. Chen Chunhai et al. designed a series of polyimide-based electrochromic materials that can achieve a colorless-to-black transition and exhibit excellent electrochromic performance. While these polyimide-based electrochromic materials are inexpensive and can achieve a colorless-to-black transition, polyimide materials, due to their amide bonds, have poor moisture and alkaline resistance, which limits the lifespan of electrochromic devices. Furthermore, the presence of strong charge transfer complexes in polyimide materials affects their transmittance. Compared to polyimide materials, polyarylether materials have superior optical properties and good moisture and alkali resistance. Their good solubility and processability also facilitate the preparation of large-area flexible devices. Furthermore, their cost is lower than that of π-conjugated polymers, making them more commercially viable.

[0003] Currently, polyarylether (PE) materials have been applied in the field of electrochromism, featuring fast response and low power consumption. However, the types of PE electrochromic materials that can achieve a colorless to black change are very limited. Achieving a black change is of great significance for the application of electrochromic technology, but most of the materials reported so far are black to colorless electrochromic materials, and the types of electrochromic materials with colorless to black change properties are scarce. Summary of the Invention

[0004] To address these challenges, the present invention provides a polyarylether polymer that can achieve a color change from colorless to magenta, boasting low cost, excellent photoelectric activity, and thermal stability. Based on the theory of color blending, the present invention utilizes this polymer in conjunction with another polyarylether polymer to fabricate an electrochromic device that can achieve a colorless to black transition, effectively alleviating the shortage of colorless to black materials in the electrochromic field.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The first aspect of the present invention provides a polyarylene ether electrochromic polymer, characterized in that it comprises repeating units of the structure represented by formula (I):

[0007]

[0008] Wherein, n is a positive integer representing the degree of polymerization of the polymer;

[0009] R is one of -H, -Br, -OCH3, -tBu, and -CN;

[0010] M is one of the structures shown in M1 to M10:

[0011]

[0012] In formula M2 and formula M7, x is 1, 2 or 3;

[0013] In formula M4, formula M8, and formula M10, Y is selected from one of disubstituted naphthalenes at positions 1,4, 1,5, 2,6, or 2,7;

[0014] The number average molecular weight of the polymer is 15-150 kDa, the weight average molecular weight is 30-300 kDa, and the dispersion index is 1.3-3.

[0015] A second aspect of the present invention provides a method for preparing a polyarylether electrochromic polymer, characterized in that it comprises the following steps:

[0016] Step 1: Dissolve the monomer compound of formula (II) and N-bromosuccinimide in DMF at room temperature to form solution a and solution b, respectively; add solution b dropwise to solution a under stirring; react for 9 to 12 hours under nitrogen; and then discharge into water; then add solid NaCl, extract the product in water with dichloromethane, and add Na2SO4 to the lower liquid to obtain the product of formula (III);

[0017]

[0018] Step 2: Dissolve the monomer compounds of formula (III) and formula (IV) and the catalyst in a medium-boiling point solvent, heat under reflux for 24 hours under a nitrogen atmosphere, dilute with dichloromethane after the reaction, wash with water, and purify by column chromatography to obtain an intermediate product of formula (V);

[0019]

[0020] Step 3: Under ice bath conditions, the monomer compound of formula (V) and the catalyst are dissolved in a low-boiling point solvent to form solution c and solution d; solution d is added dropwise to solution c under nitrogen gas with stirring; after the reaction is completed, the reactants are poured into distilled water and stirred to remove the solvent, and the solid is collected by suction filtration to obtain a prepolymer monomer of formula (VI);

[0021]

[0022] Step 4: The monomer compound of formula (VI), the monomer compound of formula (VII), the catalyst, and the reaction solvent are respectively placed in a three-necked flask equipped with a nitrogen vent, a condenser, and a mechanical stirrer, and a polymerization reaction is carried out under heating conditions using mechanical stirring; when the viscosity of the system increases rapidly, the product is discharged and the reaction is stopped in distilled water; the obtained solid is crushed, filtered, washed, and dried to obtain a polymer.

[0023]

[0024] Furthermore, in the step 1, the molar ratio of the monomer compound with the structure of formula (II) to N-bromosuccinimide is 1:(1-1.2); in the step 3, the molar ratio of the monomer compound with the structure of formula (V) to the catalyst is 1:(4-6); in the step 4, the molar ratio of the monomer compound with the structure of formula (VI), the monomer compound with the structure of formula (VII), and the catalyst is 1:1:(1.2-1.5).

[0025] Furthermore, the medium boiling point solvent in step 2 is one of toluene and xylene; the catalyst includes one or more of sodium tert-butoxide, palladium diacetate, and tri-tert-butylphosphine;

[0026] The low boiling point solvent in step 3 is one of dichloromethane and chloroform; the catalyst is one of boron tribromide and boron trichloride;

[0027] The reaction solvent in step 4 includes one or more of N-methylpyrrolidone, toluene, sulfolane, N,N-dimethylformamide, and dimethyl sulfoxide; and the catalyst is one of potassium carbonate, sodium carbonate, cesium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0028] A third aspect of the present invention provides an electrochromic device having a sandwich structure, wherein the color-changing active layer of the device is prepared from the above-mentioned polyarylene ether electrochromic polymer.

[0029] A fourth aspect of the present invention provides an electrochromic device, which is prepared from the above-mentioned polyarylene ether polymer and polymer A in proportion; the polymer A has a number average molecular weight of 15 to 150 kDa, a weight average molecular weight of 30 to 300 kDa, a dispersion index of 1.3 to 3, and a repeating unit having a structure represented by formula (VIII):

[0030]

[0031] Wherein, n is a positive integer, representing the degree of polymerization.

[0032] Furthermore, the mass ratio of the polyarylether polymer to the polymer A is 1:(2-4).

[0033] A fifth aspect of the present invention provides a method for preparing an electrochromic device, comprising the following steps:

[0034] Step 1: Clean the cut ITO glass with toluene, acetone, ethanol and deionized water in sequence;

[0035] Step 2: Dissolve a single polymer or polymer mixture in a high-boiling-point solvent, sonicate for 10 minutes, filter the polymer solution using a syringe filter, spin-coat the polymer solution on an ITO glass using a spin coater in a glove box, and dry in a vacuum oven to obtain an electrochromic film;

[0036] Step 3: obtaining a PVDF porous membrane by a non-solvent induced phase separation method, and then fully immersing the PVDF porous membrane in an electrolyte solution containing a UV-curable adhesive to obtain a photocurable gel electrolyte;

[0037] Step 4: Place the electrochromic film obtained in Step 2 on a bottom layer, then sequentially cover it with a layer of the photocurable gel electrolyte obtained in Step 3 and the ITO conductive glass obtained in Step 1. The film is then photocured using a UV lamp at a wavelength of 365 nm to produce an electrochromic device. Furthermore, the concentration of the single polymer or polymer mixture in Step 2 is 5-50 mg / mL; and the high-boiling-point solvent is one or more of N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. By introducing a phenoxazine structure into the side chain, the present invention successfully prepared a polyarylether electrochromic polymer that can change from colorless to magenta and has excellent photoelectric activity and thermal stability;

[0040] 2. Based on the color blending theory, the present invention successfully prepared an electrochromic device that changes from colorless to black by compounding the prepared polymer with another polyarylether polymer that can achieve blue color change in a certain proportion;

[0041] 3. The electrochromic device provided by the present invention has the characteristics of low cost, simple synthesis, and solution processability, is suitable for large-scale production, and has huge economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0043] Figure 1 This is the synthetic route of monomer Q1 prepared in Example 1 of the present invention;

[0044] Figure 2 is the NMR spectrum of monomer Q1 prepared in Example 1 of the present invention;

[0045] Figure 3 This is the synthetic route of monomer Q2 prepared in Example 1 of the present invention;

[0046] Figure 4 is the NMR spectrum of monomer Q2 prepared in Example 1 of the present invention;

[0047] Figure 5 This is the synthetic route of monomer Q3 prepared in Example 1 of the present invention;

[0048] Figure 6 is the NMR spectrum of monomer Q3 prepared in Example 1 of the present invention;

[0049] Figure 7 This is the synthetic route of polymer P1 prepared in Example 2 of the present invention;

[0050] Figure 8 is the infrared spectrum of polymer P1 prepared in Example 2 of the present invention;

[0051] Figure 9 is the thermogravimetric loss (TGA) curve of polymer P1 prepared in Example 2 of the present invention in nitrogen;

[0052] Figure 10 This is the synthetic route of polymer P2 prepared in Example 3 of the present invention;

[0053] Figure 11 is the infrared spectrum of polymer P2 prepared in Example 3 of the present invention;

[0054] Figure 12 is the thermogravimetric analysis (TGA) curve of polymer P2 prepared in Example 3 of the present invention in nitrogen;

[0055] Figure 13 is the spectroelectrochemical spectrum of the polymer A film prepared in Example 4 of the present invention;

[0056] Figure 14 is the cyclic voltammetry curve of the polymer P1 film prepared in Example 5 of the present invention;

[0057] Figure 15 is the spectroelectrochemical curve of the polymer P1 film prepared in Example 5 of the present invention;

[0058] Figure 16 is the optical contrast and switching time of the polymer P1 film prepared in Example 5 of the present invention;

[0059] Figure 17 is the electrochromic cycle stability curve of the polymer P1 film prepared in Example 5 of the present invention;

[0060] Figure 18 is the tinting efficiency of the polymer P1 film prepared in Example 5 of the present invention;

[0061] Figure 19 is the cyclic voltammetry curve of the polymer P2 film prepared in Example 6 of the present invention;

[0062] Figure 20 is the spectroelectrochemical curve of the polymer P2 film prepared in Example 6 of the present invention;

[0063] Figure 21 is the optical contrast and switching time of the polymer P2 film prepared in Example 6 of the present invention;

[0064] Figure 22 is the electrochromic cycle stability curve of the polymer P2 film prepared in Example 6 of the present invention;

[0065] Figure 23 is the tinting efficiency of the polymer P2 film prepared in Example 6 of the present invention;

[0066] Figure 24 is the spectroelectrochemical curve of the colorless to magenta electrochromic device prepared in Example 6 of the present invention;

[0067] Figure 25 is a switching time curve of the colorless to magenta electrochromic device prepared in Example 6 of the present invention;

[0068] Figure 261 is a cyclic voltammetry curve of the colorless to black electrochromic film prepared in Example 7 of the present invention;

[0069] Figure 27 is the spectroelectrochemical curve of the colorless to black electrochromic film prepared in Example 7 of the present invention;

[0070] Figure 28 is a switching time curve of the colorless to black electrochromic film prepared in Example 7 of the present invention;

[0071] Figure 29 1 is a cyclic voltammetry curve of the colorless to black electrochromic device prepared in Example 7 of the present invention;

[0072] Figure 30 This is the spectroelectrochemical spectrum of the colorless to black electrochromic device prepared in Example 7 of the present invention. DETAILED DESCRIPTION

[0073] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0074] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples.

[0075] Example 1

[0076] Synthesis of monomers

[0077] (1) Monomer Q1:

[0078] according to Figure 1 The monomer Q1 is synthesized by the route shown, and the specific process includes:

[0079] A 250 mL round-bottom flask was connected to a constant pressure dropping funnel. 4,4'-dimethoxytriphenylamine (9.16 g, 30 mmol) was added to 40 mL of DMF under stirring at room temperature. N-bromosuccinimide (5.34 g, 30 mmol) was then dissolved in 30 mL of DMF and added dropwise to the reaction system. The reaction progress was monitored using thin-layer chromatography. After the reaction was complete, the reaction solution was poured into distilled water and filtered to obtain monomer Q1. Monomer Q1 was characterized using proton nuclear magnetic resonance spectroscopy. Figure 2 The H NMR spectrum of Q1 proved that the monomer Q1 was successfully synthesized (as shown below).

[0080]

[0081] (2) Monomer Q2:

[0082] according to Figure 3 The monomer Q2 is synthesized by the route shown, and the specific process includes:

[0083] A 250 mL two-necked flask was used and connected to N2 protective gas, a spherical condenser, and a drying tube. Monomer Q1 (2.22 g, 5.5 mmol), phenoxazine (0.916 g, 5 mmol), catalyst Pd(OAc)2 (28.3 mg, 0.1 mmol), P(t-Bu)3 (0.04 g, 0.2 mmol), and t-BuONa (0.72 g, 7.5 mmol) were added to toluene in sequence; the mixture was heated under reflux for 24 hours. After the reaction, the monomer Q2 was purified by column chromatography. Monomer Q2 was characterized by hydrogen nuclear magnetic resonance spectroscopy. Figure 4 The hydrogen nuclear magnetic resonance spectrum of Q2 proves the successful synthesis of monomer Q2 (as shown below).

[0084]

[0085] (3) Monomer Q3:

[0086] according to Figure 5 The monomer Q3 is synthesized by the route shown, and the specific process includes:

[0087] A 250 mL three-necked flask was used and connected in sequence with Ar protective gas, a drying tube, and a constant pressure bottom liquid funnel. Q2 (0.98 g, 2 mmol) was dissolved in chloroform under ice bath conditions, and BBr3 (3.00 g, 12 mmol) was dissolved in 11 mL of chloroform and slowly added dropwise to the reaction solvent, maintaining reflux to continue the reaction. The reaction was monitored by thin layer chromatography; after the reaction was completed, the material was discharged into distilled water, filtered to obtain a purple-red powder, and purified by column chromatography to obtain monomer Q3. Monomer Q3 was characterized by hydrogen nuclear magnetic resonance spectroscopy. Figure 6 The hydrogen nuclear magnetic resonance spectrum of Q3 proves the successful synthesis of monomer Q3 (as shown below).

[0088]

[0089] Example 2

[0090] This embodiment provides a method for preparing a polyarylether polymer P1, the specific process comprising: Figure 7 Synthetic route shown):

[0091] The Q3 monomer (2.75 g, 6.00 mmol), 4,4'-difluorobenzophenone (1.31 g, 6.00 mmol), potassium carbonate (0.99 g, 7.20 mmol), 10 mL of toluene, and 12 mL of sulfolane were placed in a three-necked flask equipped with a nitrogen vent, condenser, and mechanical stirrer. The mixture was mechanically stirred. The reaction was heated at 180°C until the viscosity of the system increased rapidly. The reaction was then stopped and the hot material was discharged into water to obtain an off-white, blocky solid. The resulting solid was pulverized into a powder using a grinder and collected by filtration. The solid was then extracted and washed with distilled water, ethanol, acetone, THF, and chloroform. The washed product powder was dried in a vacuum oven to obtain polymer P1. The number average molecular weight was 40.9 kDa, the weight average molecular weight was 61.5 kDa, and the dispersity was 1.50. The structure of polymer P1 was characterized by H NMR spectroscopy and IR spectroscopy. Figure 8 and Figure 9 The NMR spectrum and IR spectrum of polymer P1 are shown respectively, which proves that polymer P1 was successfully prepared.

[0092]

[0093] Example 3

[0094] This embodiment provides a method for preparing a polyarylether polymer P2, the specific process comprising: Figure 11 Synthetic route shown):

[0095] The Q3 structural monomer (4.58g, 10.00mmol) and 4,4′-dihydroxydiphenyl sulfone (2.54g, 110.00mmol), potassium carbonate (1.66g, 12.00mmol), 10mL toluene and 16mL cyclobutane sulfone were put into a three-necked flask equipped with a nitrogen vent, a condenser and a mechanical stirrer, and the mixture was mechanically stirred. The reaction was heated at 220°C until the viscosity of the system rose rapidly, the reaction was stopped, and the material was discharged into water while hot to obtain an off-white block solid. The obtained solid was crushed into powder with a grinder and the solid was collected by filtration. It was then extracted and cleaned with distilled water, ethanol, acetone, THF and chloroform. The cleaned product powder was dried in a vacuum oven to obtain polymer P2. The number average molecular weight is 22.7kDa, the weight average molecular weight is 27.9kDa, and the dispersity is 1.23. The structure of polymer P2 was characterized by nuclear magnetic hydrogen spectrum and infrared spectrum. Figure 17 、 Figure 18 The NMR spectrum and IR spectrum of polymer P2 are shown respectively, which proves that polymer P2 was successfully prepared.

[0096]

[0097] Example 4

[0098] Preparation of polymer A:

[0099] N,N'-diphenyl-p-phenylenediamine (5.21 g, 20 mmol), 4,4'-difluorodiphenyl sulfone (5.08 g, 20 mmol), and potassium carbonate (6.63 g, 48 mmol) were added sequentially to a 100 mL flask. N-methylpyrrolidone (41 mL) and toluene (10 mL) were then added. The reaction was heated at 195°C until the viscosity of the system rapidly increased. Stirring was then stopped and the hot material was discharged into water to yield a gray-green solid. The resulting solid was pulverized and washed sequentially with distilled water and anhydrous ethanol. After washing, Soxhlet extraction was performed with acetone, tetrahydrofuran, and chloroform to yield polymer A. The number average molecular weight was 9.9 kDa, the weight average molecular weight was 15.3 kDa, and the dispersity was 1.55.

[0100] Example 5

[0101] This embodiment provides a method for preparing a colorless to magenta electrochromic device, comprising the following steps:

[0102] 5g of PVDF was dissolved in 40mL of DMF, stirred for 6 hours, and allowed to stand overnight. The solution was then scraped onto a glass plate. The glass plate coated with the polymer solution was then quickly transferred to deionized water and subjected to phase inversion for 12 hours to obtain a PVDF porous membrane. The membrane was dried in a vacuum oven for 12 hours and then immersed in an electrolyte solution to obtain a photocurable gel electrolyte. The electrolyte solution consisted of a LiClO4 solution and a UV-curable adhesive in a volume ratio of 2:1.

[0103] The polymer P1 was dissolved in DMAc at a concentration of 50 mg / mL, and then filtered using a 0.22 μm needle filter. Subsequently, 50 μL of the solution was dropped onto a 2 cm*2.5 cm ITO conductive glass and spin-coated. After drying at 150°C for 12 hours, the P1 electrochromic film was obtained. The P1 electrochromic film was sequentially covered with a gel electrolyte and blank ITO conductive glass, and then cured by UV light at a wavelength of 365 nm for 5 minutes to obtain a colorless to magenta electrochromic device.

[0104] Example 6

[0105] This embodiment provides a method for preparing a colorless to magenta electrochromic device, comprising the following steps:

[0106] 5g of PVDF was dissolved in 40mL of DMF, stirred for 6 hours, and allowed to stand overnight. The solution was then scraped onto a glass plate. The glass plate coated with the polymer solution was then quickly transferred to deionized water and subjected to phase inversion for 12 hours to obtain a PVDF porous membrane. The membrane was dried in a vacuum oven for 12 hours and then immersed in an electrolyte solution to obtain a photocurable gel electrolyte. The electrolyte solution consisted of a LiClO4 solution and a UV-curable adhesive in a volume ratio of 2:1.

[0107] The polymer P2 was dissolved in DMAc at a concentration of 50 mg / mL, and then filtered using a 0.22 μm syringe filter. Subsequently, 50 μL of the solution was dropped onto a 2 cm*2.5 cm ITO conductive glass and spin-coated. After drying at 150°C for 12 hours, the P2 electrochromic film was obtained. The P2 electrochromic film was sequentially covered with a gel electrolyte and blank ITO conductive glass, and then cured by UV light at a wavelength of 365 nm for 5 minutes to obtain a colorless to magenta electrochromic device.

[0108] Example 7

[0109] This embodiment provides a method for preparing a colorless to black electrochromic device, comprising the following steps:

[0110] 5g of PVDF was dissolved in 40mL of DMF, stirred for 6 hours, and allowed to stand overnight. The solution was then scraped onto a glass plate. The glass plate coated with the polymer solution was then quickly transferred to deionized water and subjected to phase inversion for 12 hours to obtain a PVDF porous membrane. The membrane was dried in a vacuum oven for 12 hours and then immersed in an electrolyte solution to obtain a photocurable gel electrolyte. The electrolyte solution consisted of a LiClO4 solution and a UV-curable adhesive in a volume ratio of 2:1.

[0111] Polymer P2 (25 mg) and polymer A (75 mg) were dissolved in 2 mL of N,N-dimethylacetamide, sonicated for 30 minutes, and then filtered using a 0.45 μm syringe filter. The polymer mixture was evenly spin-coated on ITO conductive glass using a spin-coating method. The spin-coated polymer film was placed in a 150°C oven and dried for 12 hours, thereby obtaining an electrochromic film that changes from colorless to black.

[0112]

[0113] A colorless to black electrochromic device is obtained by sequentially covering the electrochromic film with gel electrolyte and blank ITO conductive glass, and then curing it with ultraviolet light at a wavelength of 365nm for 5 minutes.

[0114] Figure 2 is the NMR spectrum of monomer Q1,1 H NMR (300 MHz, Chloroform-d) δ 7.28-7.20 (m, 2H), 7.07-6.99 (m, 4H), 6.87-6.74 (m, 6H), 3.79 (s, 6H), demonstrating that monomer Q1 was successfully synthesized.

[0115] Figure 4 is the NMR spectrum of monomer Q2, 1 H NMR (300 MHz, DMSO-d6) δ 7.20-7.09 (m, 6H), 7.00-6.86 (m, 6H), 6.73-6.60 (m, 6H), 5.99-5.91 (m, 2H), 3.75 (s, 6H), proving that monomer Q2 was successfully synthesized.

[0116] Figure 6 is the NMR spectrum of monomer Q3, 1 H NMR (300 MHz, DMSO-d6) δ9.41 (s, 2H), 7.12-7.00 (m, 6H), 6.86-6.74 (m, 6H), 6.66 (tdd, J=7.7, 5.5, 4.0 Hz, 6H), 6.00-5.89 (m, 2H), demonstrating the successful synthesis of monomer Q3.

[0117] Figure 8 The infrared spectrum of polymer P1 is 1200~1270cm -1 The stretching vibration absorption peak of -Ar-O-Ar- appears at 1290~1310cm -1 The stretching vibration absorption peak of CN appears at 1655cm -1 It is the stretching vibration peak of C=O connected to the benzene ring, which proves that the P1 polymer was successfully prepared.

[0118] Figure 9 This is the thermal weight loss curve of polymer P1 in N2. The 5% thermal weight loss temperature of P1 is 515℃, and the 10% thermal weight loss temperature is 541℃, showing excellent thermal stability, proving the great application potential of this material in high temperature environment.

[0119] Figure 11 This is the infrared spectrum of polymer P2, 1200~1270cm -1 The stretching vibration absorption peak of -Ar-O-Ar appears at 1290~1310cm -1 The stretching vibration absorption peak of CN appears at 1151 cm -1 The peak at is the stretching vibration peak of the sulfone group, proving that polymer P2 was successfully prepared.

[0120] Figure 12This is the thermal weight loss curve of polymer P2 in N2. The 5% thermal weight loss temperature of P2 is 482°C, and the 10% thermal weight loss temperature is 523°C. It has excellent thermal stability, demonstrating its great potential for application under extremely high temperature conditions.

[0121] Figure 13 Figure 2 is the spectroelectrochemical curve of polymer A. Polymer A can achieve reversible changes from colorless to green and then to blue at voltages of 0.4V and 0.6V respectively. In addition, polymer A has strong absorption of light with a wavelength of 627nm at a voltage of 0.6~1V.

[0122] Figure 14 The cyclic voltammetry curve of polymer P1 film shows that its onset voltage is 0.32 V, which proves its high electrochemical activity. It also has two symmetrical pairs of redox peaks, which proves that it has two electroactive sites and the film is electrochemically reversible.

[0123] Figure 15 Figure 3 is the spectroelectrochemical curve of polymer P1 film. Polymer P1 has almost no absorption in the visible light range at 0 V voltage, which proves that it is transparent at 0 V voltage. With the gradual increase of voltage (0.6 V), P1 first has an absorption peak near 542 nm, which proves that the polymer is magenta at this time. With the further increase of voltage (0.9 V), P1 has absorption peaks at 542 nm and 782 nm, and the polymer appears purple at this time.

[0124] Figure 16 The optical contrast and switching time of polymer P1 film show that polymer P1 can achieve fast color switching, with a coloring time of 3.75s and a fading time of 1.68s. Its maximum optical contrast is 32.05%, proving its application potential in the field of electrochromism.

[0125] Figure 17 This is the electrochromic cycle stability curve of polymer P1 film. Polymer P1 still has electrochromic ability after 150 cycles.

[0126] Figure 18 The coloring efficiency of polymer P1 film is as high as 126cm 2 / C, demonstrating that only a small amount of charge is required to achieve large optical modulation.

[0127] Figure 19 This is the cyclic voltammetry curve of polymer P2 film. The onset voltage is 0.35V, showing that P2 has excellent electrochemical activity and electrochemical reversibility.

[0128] Figure 20The spectroelectrochemical curve of polymer P2 film proves that polymer P2 has absorption at 545nm and 763nm at voltages of 0.6V and 0.9V, corresponding to the changes of magenta and purple, respectively.

[0129] Figure 21 Figure 3 is the maximum optical contrast and switching time curve of polymer P2 film. The optical contrast of polymer P2 is 49.78%, the coloring time is 3.83s, and the fading time is 1.80s, which indicates that P2 has excellent electrochromic properties.

[0130] Figure 22 This is the electrochromic cycle stability curve of the polymer P2 film. The optical contrast of P2 remains almost unchanged after 850 cycles, demonstrating that the P2 material can maintain stable electrochromic properties during long-term use.

[0131] Figure 23 is the coloring efficiency of polymer P2 film. It can be seen from the figure that the coloring efficiency of P2 is as high as 218cm 2 / C, indicating that P2 only needs a small amount of charge to significantly change its optical properties.

[0132] Figure 24 The spectroelectrochemical curves of the electrochromic device prepared for P2 polymer, which changes from colorless to magenta, demonstrate the great potential of P2 polymer in the application of electrochromic technology.

[0133] Figure 25 The switching time curve of the electrochromic device that changes from colorless to magenta prepared by P2 polymer shows that the color changing time is 9s, indicating that the device can achieve fast color switching.

[0134] Figure 26 The cyclic voltammetry curve of the electrochromic film that changes from colorless to black in a three-electrode system proves that the electrochromic film has electrochemical activity and can undergo reversible redox reactions.

[0135] Figure 27 This is the spectral electrochemical spectrum of the electrochromic film that changes from colorless to black in a three-electrode system. It can be seen from the figure that the film has almost no absorption at 0 V voltage, but as the voltage gradually increases, the film has a wide absorption in the visible light region (400-700nm), proving that the electrochromic film can achieve a change from colorless to black.

[0136] Figure 28 The switching time of the electrochromic film from colorless to black is 3.8s for coloring and 3.6s for fading, which proves that the colorless to black electrochromic film prepared by the present invention has a fast response speed.

[0137] Figure 29 The cyclic voltammetry curve of the electrochromic device that changes from colorless to black. The oxidation peak area of the device is basically consistent with the reduction peak area, proving that the device has electrochemical reversibility.

[0138] Figure 30 This is the spectral electrochemical curve of the colorless to black electrochromic device. It can be seen from the spectral electrochemical curve that the device can fully absorb the visible light spectrum at a voltage of 2.3V, thereby achieving black change, which proves the great potential of the colorless to black electrochromic material in the field of electrochromism.

[0139] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A polyarylether electrochromic polymer, characterized in that: Comprising a repeating unit of the structure shown in formula (I): Wherein, n is a positive integer representing the degree of polymerization of the polymer; R is one of -H, -Br, -OCH3, -tBu, and -CN; M is one of the structures shown in M1 to M10: In formula M2 and formula M7, x is 1, 2 or 3; In formula M4, formula M8, and formula M10, Y is selected from one of disubstituted naphthalenes at positions 1,4, 1,5, 2,6, or 2,7; The number average molecular weight of the polymer is 15-150 kDa, the weight average molecular weight is 30-300 kDa, and the dispersion index is 1.3-3.

2. The method for preparing a polyarylether electrochromic polymer according to claim 1, characterized in that: The following steps are involved: Step 1: Dissolve the monomer compound of formula (II) and N-bromosuccinimide in DMF at room temperature to form solution a and solution b, respectively. Add solution b dropwise to solution a under stirring, allow nitrogen to react for 9 to 12 hours, and then discharge into water. Then, add solid NaCl, extract the product in water with dichloromethane, and add Na2SO4 to the lower liquid to obtain the product of formula (III). Step 2: Dissolve the monomer compounds of formula (III) and formula (IV) and the catalyst in a medium-boiling point solvent, heat under reflux for 24 hours under a nitrogen atmosphere, dilute with dichloromethane after the reaction, wash with water, and purify by column chromatography to obtain an intermediate product of formula (V); Step 3: Under ice bath conditions, the monomer compound of formula (V) and the catalyst are dissolved in a low-boiling point solvent to form solution c and solution d; solution d is added dropwise to solution c under nitrogen gas with stirring; after the reaction is completed, the reactants are poured into distilled water and stirred to remove the solvent, and the solid is collected by suction filtration to obtain a prepolymer monomer of formula (VI); Step 4: The monomer compound of formula (VI), the monomer compound of formula (VII), the catalyst, and the reaction solvent are respectively placed in a three-necked flask equipped with a nitrogen vent, a condenser, and a mechanical stirrer, and a polymerization reaction is carried out under heating conditions using mechanical stirring; when the viscosity of the system increases rapidly, the product is discharged and the reaction is stopped in distilled water; the obtained solid is crushed, filtered, washed, and dried to obtain a polymer.

3. The method for preparing a polyarylether electrochromic polymer according to claim 2, characterized in that: In the step 1, the molar ratio of the monomer compound of formula (II) to N-bromosuccinimide is 1:(1-1.2); In the step 3, the molar ratio of the monomer compound of formula (V) to the catalyst is 1:(4-6); In the step 4, the molar ratio of the monomer compound of formula (VI), the monomer compound of formula (VII), and the catalyst is 1:1:(1.2-1.5).

4. The method for preparing a polyarylether electrochromic polymer according to claim 2, wherein: The medium boiling point solvent in step 2 is one of toluene and xylene; the catalyst includes one or more of sodium tert-butoxide, palladium diacetate, and tri-tert-butylphosphine; The low boiling point solvent in step 3 is one of dichloromethane and chloroform; the catalyst is one of boron tribromide and boron trichloride; The reaction solvent in step 4 includes one or more of N-methylpyrrolidone, toluene, sulfolane, and N,N-dimethylformamide; and the catalyst is one of potassium carbonate and cesium carbonate.

5. An electrochromic device, characterized in that: The device has a sandwich structure, and the color-changing active layer of the device is prepared from the polyarylether electrochromic polymer according to claim 1.

6. An electrochromic device, characterized in that: The device is prepared by the polyarylene ether polymer according to claim 1 and polymer A in proportion; The polymer A has a number average molecular weight of 15 to 150 kDa, a weight average molecular weight of 30 to 300 kDa, a dispersion index of 1.3 to 3, and a repeating unit having a structure represented by formula (VIII): Wherein, n is a positive integer, representing the degree of polymerization.

7. The electrochromic device according to claim 6, characterized in that: The mass ratio of the polyarylether polymer according to claim 1 to polymer A in the electrochromic layer of the device is 1:(2-4).

8. The method for preparing an electrochromic device according to claims 5 to 7, characterized in that: The following steps are involved: Step 1: Clean the cut ITO glass with toluene, acetone, ethanol and deionized water in sequence; Step 2: Dissolve a single polymer or polymer mixture in a high-boiling-point solvent, sonicate for 10 minutes, filter the polymer solution using a syringe filter, spin-coat the polymer solution on an ITO glass using a spin coater in a glove box, and dry in a vacuum oven to obtain an electrochromic film; Step 3: obtaining a PVDF porous membrane by a non-solvent induced phase separation method, and then fully immersing the PVDF porous membrane in an electrolyte solution containing a UV-curable adhesive to obtain a photocurable gel electrolyte; Step 4: Place the electrochromic film obtained in step 2 on the bottom layer, and cover it with a layer of photocurable gel electrolyte obtained in step 3 and ITO conductive glass obtained in step 1 in sequence, and use a UV lamp box to perform photocuring at a wavelength of 365nm to obtain an electrochromic device.

9. The method for preparing an electrochromic device according to claim 8, characterized in that: The concentration of the single polymer or polymer mixture in step 2 is 5 to 50 mg / mL; The high boiling point solvent is one or more of N-methylpyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide.

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