Polyarylether polymer based on tetraphenylethylene and derivatives thereof, electrochromic device and preparation method of polyarylether polymer

Abstract

The invention belongs to the technical field of organic photoelectric functional materials, and particularly relates to a polyarylether polymer based on tetraphenylethylene and derivatives thereof, an electrochromic device and a preparation method of the polyarylether polymer. The number of chromogenic groups phenoxazine is increased to increase the chromogenic degree, meanwhile, a tetraphenyl ethylene unit is constructed on a main chain of the polymer, the electrochromic polyarylether polymer is successfully prepared, and an electrochromic device capable of realizing colorless to magenta is prepared by utilizing the polymer. The problem that color-changing materials from colorless to red wave bands are scarce is solved. In addition, according to the color mixing principle, the polymer is mixed with another polymer in proportion, and an electrochromic device from colorless to black is successfully prepared. The device can be converted between colorless transparent and black along with different applied potentials, has the characteristics of simple synthesis, good stability and solution preparation, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic functional materials, and particularly relates to a polyarylether polymer based on tetraphenylethylene and its derivatives, an electrochromic device and a preparation method thereof. Background Art

[0002] Electrochromism refers to a phenomenon in which the optical properties of a material change reversibly under the action of an external electric field. This phenomenon can be applied to the design of modern scientific and technological products with variable light transmittance or reflectance, such as smart windows or dimmable rearview mirrors. In the 1960s, Satyen K. Deb published a pioneering work on the electrochromism of molybdenum and tungsten oxide thin films: he observed that these colorless thin film materials could be reduced to dark blue using electrochemical methods and could be re-oxidized to colorless again through electrochemical methods. This marked the establishment of electrochromic technology.

[0003] Compared with inorganic electrochromic materials, another major branch of organic materials is polymer electrochromic materials. Polymer materials not only retain the characteristics of solution processability and easy chemical modification of organic materials but also avoid the limitation that small molecule materials can only change color in a liquid environment, and have great advantages over inorganic materials and organic small molecules in the use of flexible devices.

[0004] Among them, electrochromic materials from colorless to black have great market application prospects and have always received much attention. From the perspective of spectroscopy, the requirement to achieve black is to absorb all wavelengths in the visible light region (400 - 800 nm). The research on black electrochromic devices was mainly based on the research work of the Reynolds group at the beginning. By copolymerizing 3,4-ethylenedioxythiophene or 3,4-propylenedioxythiophene derivatives and chromophores with complementary absorption curves, full-color absorption was achieved in the neutral state, and colorless was achieved in the oxidized state, thus making a pioneering contribution to black-to-colorless electrochromic polymers. It can be seen that there is a high research interest in colorless-to-black electrochromic materials at home and abroad.

[0005] Currently, most electrochromic materials from transparent to colored show colors such as yellow, green, blue, etc., and electrochromic materials in the red band are relatively scarce. Based on the subtractive color mixing principle of electrochromism, if an electrochromic material from transparent to black is to be prepared, a magenta electrochromic material can be selected as one of the blend components. And phenoxazine is a molecule that is colorless in the neutral state and magenta in the oxidized state, and is widely used in fields such as dyes, organic optoelectronics, and biological probes. As a heterocyclic chromophore, phenoxazine integrates electron-rich nitrogen and oxygen atoms, resulting in a dihedral angle formed between the two benzene rings in its chemical structure.

[0006] In the field of electrochromics, electrochromic devices that change from colorless and transparent in the neutral state to black in the oxidized state can be widely used in the fields of displays, smart windows, military camouflage, rearview mirrors, and solar cells. Therefore, there is still sufficient research space for electrochromic materials that change from colorless to black. Summary of the Invention

[0007] Colorless-to-black electrochromic materials have always received extensive attention due to their long-term huge application prospects. Aiming at the problem of the imperfect strategy for synthesizing colorless-to-black electrochromic polymer materials at present, the present invention increases the color display degree by increasing the number of chromogenic groups phenoxazine, and constructs a tetraphenylethylene unit in the polymer main chain. A kind of electrochromic polyarylether polymer is successfully prepared, and an electrochromic device capable of realizing colorless to magenta is prepared by using this polymer, solving the problem of the scarcity of color-changing materials in the colorless to red wavelength band. In addition, according to the color mixing principle, the present invention mixes this polymer with another polymer in a certain proportion, and successfully prepares an electrochromic device that changes from colorless to black.

[0008] The object of the present invention is achieved by the following technical solutions:

[0009] The first aspect of the present invention provides a polyarylether polymer based on tetraphenylethylene and its derivatives, characterized in that: it includes a repeating unit shown in formula (Ⅰ):

[0010]

[0011] Among them, n is a positive integer representing the degree of polymerization;

[0012] R is one of the structures shown in R1-R8:

[0013]

[0014] X is one of the structures shown in X1-X8:

[0015]

[0016] In formulas (X3) and (X7), x is 1, 2 or 3;

[0017] In formulas (X4) and (X8), Y is selected from one of naphthalenes that are disubstituted at the 1,4-position, 1,5-position, 2,6-position or 2,7-position; the number average molecular weight of the polymer is 15-50 kDa, the weight average molecular weight is 20-60 kDa, and the dispersion index is 1.2-3.

[0018] The second aspect of the present invention provides a preparation method of a polyarylether polymer based on tetraphenylethylene and its derivatives, which comprises the following steps:

[0019] Step 1: Add the catalyst, the monomer compound of formula (II), and the monomer compound of formula (III) into a low-boiling solvent in sequence. After stirring at low temperature, pour the reaction mixture into hydrochloric acid, and perform post-treatment on the reaction product to obtain a product with the structure of formula (IV);

[0020]

[0021]

[0022] Step 2: Add the monomer compound of formula (IV), the monomer compound of formula (V), and the catalyst into a medium-boiling solvent in sequence, and heat and stir; after the reaction is completed, perform post-treatment on the reaction product to obtain an intermediate product with the structure of formula (VI);

[0023]

[0024] Step 3: Add the monomer compound of formula (VI) and the catalyst into a low-boiling solvent in sequence. After the reaction is completed, pour the reaction mixture into a saturated potassium carbonate aqueous solution, and perform post-treatment on the crude product to obtain an intermediate product with the structure of formula (VII);

[0025]

[0026] Step 4: Add the monomer compound of formula (VII) and the catalyst into a low-boiling solvent in sequence, and stir the reaction in an ice bath; after the reaction is completed, perform post-treatment on the reaction product to obtain a prepolymer monomer with the structure of formula (VIII);

[0027]

[0028] Step 5: Put the monomer compound of formula (VIII), the monomer of formula (IX) with a carbonyl or sulfone group, the catalyst, and a high-boiling solvent into a three-necked flask equipped with a nitrogen inlet, a condenser, and a mechanical stirrer. Mechanically stir the mixture. After heating for 11 hours, the viscosity of the system begins to increase; stop the reaction, cool to room temperature, and pour the polymer solution into distilled water; finally, crush, filter, wash, and dry the solid obtained from the reaction to obtain a polymer containing optoelectronic functional groups.

[0029]

[0030] Furthermore, in step one, the molar ratio of the monomer of formula (II), the monomer of formula (III), and the catalyst is 1:1:(1-2); in step two, the molar ratio of the catalyst, the monomer of formula (IV), and the monomer of formula (V) is 1:1:(1-1.5); in step three, the molar ratio of the monomer of formula (VI), the catalyst, and the reducing metal is 1:4:(4-5); in step four, the molar ratio of the monomer of formula (VII) and the catalyst is 1:(5.5-6.5); in step five, the molar ratio of the monomer of formula (VIII) and the catalyst is 1:1:(1-2).

[0031] Furthermore, in step 1, the catalyst is one of aluminum chloride, ferric chloride, zinc chloride or boron trifluoride; in step 2, the catalyst is one or more of sodium tert-butoxide, tri(dibenzylideneacetone)dipalladium, and tri-tert-butylphosphine; in step 3, the catalyst is one of titanium tetrachloride or titanium trichloride and one of magnesium, zinc, sodium, and lithium; in step 4, the catalyst is one of boron tribromide or boron trifluoride; in step 5, the catalyst is a carbonate, such as one of potassium carbonate, sodium carbonate, cesium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0032] Furthermore, in step 1, step 3, and step 4, the low boiling point solvent includes one of dichloromethane, tetrahydrofuran, and chloroform; in step 2, the medium boiling point solvent includes one of toluene, xylene, and butanol; in step 5, the high boiling point solvent includes one of N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide, and dimethyl sulfoxide.

[0033] Furthermore, in step one, the reaction temperature is 0 to 30°C, and the reaction time is 2 to 5 hours; in step two, the reaction temperature is 90 to 180°C, and the reaction time is 9 to 15 hours; in step three, the reaction temperature is 100 to 120°C, and the reaction time is 6 to 12 hours; in step four, the reaction temperature is -5 to 0°C, and the reaction time is 10 to 20 hours; in step five, the polymerization reaction temperature is 180 to 205°C, and the polymerization reaction time is 18 to 21 hours; the reactions in steps one to five are all carried out under protective gas, and the protective gas is nitrogen or argon.

[0034] A third aspect of the present invention provides an electrochromic device, wherein the device is a sandwich structure, and the electrochromic layer in the device is prepared from the polyarylether polymer according to claim 1.

[0035] A fourth aspect of the present invention provides an electrochromic device, wherein the electrochromic layer in the device is prepared by the polyarylether polymer according to claim 1 and polymer A in proportion, wherein the polymer A is one of the structures represented by formula (X) or formula (XI):

[0036]

[0037] Among them, n is a positive integer representing the degree of polymerization.

[0038] Furthermore, the mass ratio of the polyarylether polymer provided in the first aspect of the present invention to polymer A in the electrochromic layer of the device is 1:(1.5 - 4).

[0039] The fifth aspect of the present invention provides a method for preparing an electrochromic device, comprising the following steps:

[0040] Step 1: Mix a lithium perchlorate solution and an ultraviolet curable adhesive according to a volume ratio and dissolve them in a high-boiling solvent. After stirring, fully immerse a PVDF membrane in the solution to obtain an electrolyte layer;

[0041] Step 2: Dissolve a single polymer or a polymer mixture in a high-boiling solvent. After dissolution, filter the solution with a filter head, and then spin-coat the solution evenly on conductive glass. After drying, an ITO conductive glass with an electrochromic thin film is obtained;

[0042] Step 3: Place a blank ITO glass and the ITO conductive glass covered with an electrochromic thin film prepared in Step 2 on both sides of the electrolyte layer obtained in Step 1, and cure them with ultraviolet light to obtain an electrochromic device.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] 1. The present invention increases the color display degree by increasing the number of chromogenic groups phenoxazine, and at the same time constructs a tetraphenylethylene unit in the polymer main chain, and successfully prepares an electrochromic polyarylether polymer;

[0045] 2. The present invention prepares an electrochromic device capable of realizing colorless to magenta based on the polyarylether polymer; in addition, the present invention mixes the polymer with another polymer in a certain proportion, and successfully prepares an electrochromic device from colorless to black;

[0046] 3. The electrochromic device prepared by the present invention can be transformed between colorless transparent and black with different applied potentials, has the characteristics of simple synthesis and solution preparation, and can solve the problems of low saturation of existing black electrochromic materials and unsuitability for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0048] Figure 1 It is the synthesis route of monomer M1 prepared in the embodiment of the present invention;

[0049] Figure 2 It is the NMR spectrum of monomer M1 prepared in Example 1 of the present invention;

[0050] Figure 3 It is the synthesis route of monomer M2 prepared in Example 1 of the present invention;

[0051] Figure 4 It is the NMR spectrum of monomer M2 prepared in Example 1 of the present invention;

[0052] Figure 5 It is the synthesis route of monomer M3 prepared in Example 1 of the present invention;

[0053] Figure 6 It is the NMR spectrum of monomer M3 prepared in Example 1 of the present invention;

[0054] Figure 7 It is the synthesis route of monomer M4 prepared in Example 1 of the present invention;

[0055] Figure 8 It is the NMR spectrum of monomer M4 prepared in Example 1 of the present invention;

[0056] Figure 9 It is the infrared spectra of monomers M1, M2, M3, M4 and polymer P1 prepared in Examples 1-2 of the present invention;

[0057] Figure 10 It is the thermogravimetric (TGA) curve of polymer P1 prepared in Example 2 of the present invention;

[0058] Figure 11 It is the spectroelectrochemical curve of the electrochromic polymer P1 film prepared in Example 2 of the present invention;

[0059] Figure 12 It is the spectroelectrochemical curve of the colorless to magenta electrochromic device prepared in Example 4 of the present invention;

[0060] Figure 13 It is the electrochromic cycling stability curve of the colorless to magenta electrochromic device prepared in Example 4 of the present invention;

[0061] Figure 14 It is the electrochromic contrast and switching time curve of the colorless to magenta electrochromic device prepared in Example 4 of the present invention;

[0062] Figure 15 It is the cyclic voltammogram curve of the colorless to magenta electrochromic device prepared in Example 4 of the present invention;

[0063] Figure 16It is the cyclic voltammogram of the colorless to black electrochromic device prepared in Examples 5-6 of the present invention;

[0064] Figure 17 It is the spectroelectrochemical curve of the colorless to black electrochromic device prepared in Examples 5-6 of the present invention;

[0065] Figure 18 It is the switching time curve of the colorless to black electrochromic device prepared in Examples 5-6 of the present invention;

[0066] Figure 19 It is the cyclic stability curve of the colorless to black electrochromic device prepared in Examples 5-6 of the present invention. Detailed implementation manners

[0067] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0068] For clearer illustration, the following detailed description is provided through the following examples.

[0069] Example 1

[0070] Synthesis of monomers

[0071] (1) Monomer M1

[0072] According to Figure 1 The synthetic route shown to synthesize monomer M1. The specific process includes:

[0073] Select a 250 mL three-necked flask, connect a nitrogen protection gas and a ground glass stopper in sequence, and pass nitrogen for 10 minutes in advance. Add 4-bromobenzoyl chloride (4.38926 g, 0.02 mmol), anisole (2.7035 g, 0.025 mmol), and aluminum chloride (3.3335 g, 0.025 mmol) to the three-necked flask containing 60 mL of dichloromethane in sequence. Under the protection of nitrogen and in an ice bath, stir and react for 3 hours. Then pour the reaction mixture into a 20% hydrochloric acid solution, extract with dichloromethane, dry with anhydrous sodium sulfate, and place the obtained solid in a vacuum oven to dry to obtain 10 g of a light orange-pink solid with a yield of 85.87%. The structure of M1 was characterized by 1H NMR, proving that monomer M1 was successfully prepared (as shown in the following figure).

[0074]

[0075] (2) Monomer M2

[0076] According toFigure 3 The synthetic route shown is used to synthesize monomer M2, and the specific process includes:

[0077] A 250mL three-necked flask was selected, and nitrogen protective gas, ground stopper, and spherical condenser were connected in sequence, and nitrogen was passed for 20 minutes in advance. M1 (3.2025g, 11mmol), phenoxazine (1.8320g, 10mmol), sodium tert-butoxide (1.4415g, 15mmol), palladium acetate (0.0449g, 0.2mmol) were added to the three-necked flask in sequence, and 100mL toluene was added as the reaction solvent, and finally 94μL tri-tert-butylphosphine was added. After heating and stirring for 24 hours, the reaction solution was poured into water, and the monomer M2 was obtained after post-reaction treatment. The obtained solid was placed in a vacuum oven for drying. 2.91g of bright orange solid was obtained, and the yield was 74%. The structure of M2 was characterized by nuclear magnetic hydrogen spectrum, proving that the monomer M2 was successfully prepared (as shown below).

[0078]

[0079] (3) Monomer M3

[0080] according to Figure 5 The synthetic route shown is used to synthesize monomer M3, and the specific process includes:

[0081] A 250mL three-necked flask was selected, and nitrogen protective gas, ground stopper, and spherical condenser were connected in sequence, and nitrogen was passed for 20 minutes in advance. Zinc powder (2.2883g, 0.035mol) was added to a three-necked flask containing 40mL of tetrahydrofuran, and titanium tetrachloride (5.9749g, 0.0315mol) was slowly added at -5°C. After heating and refluxing for 3 hours, it was cooled to -5°C, 1mL of pyridine was added, and mixed for 1 hour. Finally, a tetrahydrofuran solution containing monomer M2 (2.7541g, 0.007mol) was slowly added to the above mixed solution, and stirred under reflux for 12 hours. The reaction was poured into a saturated potassium carbonate aqueous solution, and monomer M3 was obtained after post-reaction treatment. The obtained solid was placed in a vacuum oven for drying. 1.82g of yellow solid was obtained, and the yield was 69%. The structure of M3 was characterized by nuclear magnetic hydrogen spectrum, proving that monomer M3 was successfully prepared (as shown below).

[0082]

[0083] (4) Monomer M4

[0084] according to Figure 7 The synthetic route shown is used to synthesize monomer M4, and the specific process includes:

[0085] A 250 mL three-necked flask was selected and successively connected with nitrogen protection and a ground glass stopper. Monomer M3 (3.7745 g, 0.005 mol) was added to the three-necked flask containing 90 mL of chloroform, and then 2.89 mL of boron tribromide was slowly added dropwise. Under the condition of an ice bath, the reaction was stirred for 12 hours. After the reaction work-up, monomer M4 was obtained, and the resulting solid was dried in a vacuum oven. 3.08 g of a grass green solid was obtained with a yield of 85%. The structure of M4 was characterized by 1H NMR, demonstrating the successful preparation of monomer M4 (as shown in the figure below).

[0086]

[0087] Example 2

[0088] This example provides a method for preparing a polyarylether polymer P1, comprising the following steps:

[0089] Monomer M4 (3.63415 g, 0.005 mol), 4,4'-difluorodiphenyl sulfone (1.2713 g, 0.005 mol), potassium carbonate (0.8292 g, 0.006 mol), 10 mL of toluene, and 11.67 mL of sulfolane with a solids content of 25% were put into a three-necked flask equipped with a nitrogen inlet, a condenser, and a mechanical stirrer. The mixture was mechanically stirred and heated at 180 °C for 21 hours. Then, the viscosity of the system increased rapidly, and the reaction ended. Heating and stirring were stopped, and after cooling to room temperature, the polymer solution was poured into distilled water. The obtained solid was yellow with a white film on the surface. The solid was crushed into powder in a pulverizer, and the solid was filtered and collected. Then, it was washed by boiling in distilled water and ethanol and then filtered by suction. Finally, it was extracted with tetrahydrofuran, and the product was collected and dried in a vacuum drying oven. A golden yellow solid was obtained, named polymer P1. The product mass was 3.8 g, and the yield was 80%. The number average molecular weight was 16 kDa, the weight average molecular weight was 24 kDa, and the dispersity was 1.50. The structure of polymer P1 was characterized by infrared spectroscopy, demonstrating the successful preparation of polymer P1 (as shown in the figure below).

[0090]

[0091] Example 3

[0092] This example provides a method for preparing a polyarylether polymer P2 (as shown in the figure below), comprising the following steps:

[0093] 3.6342 g (0.005 mol) of M4 structural monomer, 4,4-difluorobenzophenone (1.091 g, 0.005 mol), potassium carbonate (0.8292 g, 0.006 mol), 10 mL of toluene, and 11.67 mL of sulfolane with a solids content of 25% were added into a three-necked flask equipped with a nitrogen inlet, a condenser, and a mechanical stirrer. The mixture was mechanically stirred and heated at 180 °C for 21 hours. After that, the viscosity of the system increased rapidly, and the reaction ended. The heating and stirring were stopped, and after cooling to room temperature, the polymer solution was poured into distilled water. The obtained solid was yellow. The solid was crushed into powder in a pulverizer, and the solid was collected by filtration. After washing with distilled water and ethanol by boiling and then filtering, and finally extracting with tetrahydrofuran and chloroform, the product was collected and dried in a vacuum drying oven. A golden-yellow solid was obtained, named polymer P2. The mass of the product was 3.5 g, and the yield was 75%. The number-average molecular weight was 15 kDa, the weight-average molecular weight was 21 kDa, and the dispersity was 1.47.

[0094]

[0095] Example 4

[0096] This example provides a method for preparing an electrochromic device from colorless to magenta, comprising the following steps:

[0097] 50 mg of polymer P1 was dissolved in 1 mL of DMAc solvent, and then the polymer solution was spin-coated on a 1 * 5.5 cm conductive glass. After drying the solvent, a polymer thin film with ITO conductive glass as the substrate was prepared, with a size of 1 cm * 2.5 cm. Then, the prepared gel electrolyte was laid flat on top of the polymer thin film, and a blank ITO glass was covered on the other side of the gel electrolyte. Subsequently, the whole was cured by ultraviolet light to obtain a sandwich-type electrochromic device.

[0098] Example 5

[0099] This example provides a method for preparing an electrochromic device from colorless to black, comprising the following steps:

[0100] 25 mg of polymer P1 and 50 mg of polymer A were respectively dissolved in 1 mL of DMF solvent. After complete dissolution, the polymer solution was filtered through a 0.8 μm filter head. Then, by spin-coating, the polymer mixed solution was evenly spread on the ITO glass, and then placed in an oven and dried at 150 °C to remove the solvent, thus preparing an electrochromic polymer thin film based on tetraphenylethylene from colorless to black.

[0101]

[0102] An ITO glass coated with a mixed polymer and a blank ITO glass were respectively placed on both sides of the gel electrolyte and cured by ultraviolet light. When the two ITO glasses adhered to the gel electrolyte and would not fall off under no external force, the device was fabricated (named AZ21).

[0103] Example 6

[0104] The difference between this example and Example 5 is that Polymer A was replaced with Polymer B (as shown in the following figure), and the remaining steps were the same. The prepared colorless to black electrochromic device was named MZ21.

[0105]

[0106] Figure 2 It is the NMR spectrum of monomer M1, 1 1H NMR (300 MHz, DMSO-d6) δ 7.79–7.73 (m, 4H), 7.66–7.60 (m, 2H), 7.15–7.04 (m, 2H), 3.86 (s, 3H), which proved the successful synthesis of monomer M1.

[0107] Figure 4 It is the NMR spectrum of monomer M2, 1 1H NMR (300 MHz, DMSO-d6) δ 8.00–7.90 (m, 2H), 7.90–7.80 (m, 2H), 7.65–7.55 (m, 2H), 7.19–7.08 (m, 2H), 6.83–6.63 (m, 6H), 6.03–5.94 (m, 2H), 3.88 (s, 3H), which proved the successful synthesis of monomer M2.

[0108] Figure 6 It is the NMR spectrum of monomer M3, 1 1H NMR (300 MHz, DMSO-d6) δ 7.30–7.21 (m, 4H), 7.21–7.16 (m, 4H), 7.06 (d, J = 8.8 Hz, 2H), 7.01–6.92 (m, 2H), 6.84–6.80 (m, 4H), 6.70 (d, J = 1.6 Hz, 2H), 6.67 (d, J = 1.6 Hz, 2H), 6.58 (td, J = 7.6, 1.5 Hz, 4H), 6.53–6.44 (m, 4H), 5.77 (dd, J = 7.9, 1.5 Hz, 4H), 3.73 (s, 6H), which proved the successful synthesis of monomer M3.

[0109] Figure 81H NMR (300 MHz, DMSO-d6) δ 9.46 (s, 2H), 7.32–7.11 (m, 8H), 6.89 (dd, J = 18.9, 8.4 Hz, 4H), 6.79–6.39 (m, 16H), 5.89–5.69 (m, 4H), which proves the successful synthesis of monomer M4.

[0110] Figure 9 In the spectral comparison between POZ and BMPM-POZ, the peak of the N-H bond disappears, proving the successful connection of BMPM and phenoxazine; in the infrared spectra of BMPM, BMPM-POZ and TPE-POZ, the peak at 2800–2860 cm -1 is the stretching vibration peak of the C-H bond in the methoxy group; in the infrared spectrum of PAES-TPE-POZ, the peak at 1150 cm-1 is the stretching vibration peak of the sulfone connected to the benzene ring; the stretching vibration absorption peak of the aromatic ether bond appears at 1240 cm -1 , indicating the successful preparation of the polymer.

[0111] Figure 10 This is the thermogravimetric curve of polymer P1. As shown in the figure, before 420 °C, the polymer hardly has any weight loss. The excellent thermal stability is beneficial to the extension of the service life of this kind of material in the future.

[0112] Figure 11 This is the spectroelectrochemical curve of polymer P1. When the voltage increases from 0 to 0.6 V, the absorption curve shows a red shift, indicating that as the voltage increases, the band gap of the polymer gradually decreases. When it increases to 0.6 V, a new absorption peak appears at 544 nm, and at this time it shows magenta.

[0113] Figure 12 This is the spectroelectrochemical curve of the electrochromic device from colorless to magenta. As the voltage increases, a new absorption peak appears at 543 nm, and at this time it shows magenta. This process is also consistent with the cyclic voltammogram curve, indicating that this polymer has excellent electrochemical stability and great application potential in the optoelectronic field.

[0114] Figure 13 This is the electrochromic cyclic stability curve of the electrochromic device from colorless to magenta. At 543 nm, 0–0.6 V, the film remains stable after working for 60 cycles.

[0115] Figure 14 This is the contrast and switching time curve of the electrochromic device from colorless to magenta; at 543 nm, applying a square wave voltage of 0–0.6 V, the coloring time is 2.34 s, the fading time is 1.28 s, and the optical contrast is 43.55%.

[0116] Figure 15 It is the cyclic voltammogram of a colorless to magenta electrochromic device. This figure shows that the oxidation reaction of this device starts at 2.4 V and there is only one oxidation peak.

[0117] Figure 16 It is the cyclic voltammogram of two colorless to black electrochromic devices. This figure shows that the two devices are colored at around 2.5 V and the devices are bleached at -2 V.

[0118] Figure 17 It is the spectroelectrochemical curve of two colorless to black electrochromic devices. The device based on AZ21 is colored at a voltage of 2.3 V. The device based on MZ21 is colored at a voltage of 2.1 V. However, as the voltage increases, the absorption peak shows a red shift, and the absorption of the MZ21 device at 435 nm is further enhanced.

[0119] Figure 18 It is the switching time curve of two colorless to black electrochromic devices. The coloring and fading times of AZ21 are 19.89 s and 14.56 s respectively, and the coloring and fading times of MZ21 are 22.56 s and 0.9 s respectively.

[0120] Figure 19 However, MZ21 shows more excellent electrochromic cycle stability. After 450 cycles, its optical contrast drops to 73% of the initial value. While AZ21 shows obvious performance degradation, which may be related to the morphology of the color-changing layer and the composition process of the device.

[0121] Solubility test

[0122] Table 1: Solubility test data

[0123]

[0124] 10 mg of polymer is dissolved in 1 mL of solvent

[0125] ++ indicates soluble at room temperature; + indicates soluble when heated; - insoluble even when heated

[0126] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A polyarylether polymer based on tetraphenylethylene and its derivatives, 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; R is one of the structures shown by R1 to R8; X is one of the structures shown by X1 to X8; In formula (X3) and (X7), x is 1, 2 or 3; In formula (X4) and (X8), Y is selected from one of the naphthalenes with double substitution at the 1,4-position, 1,5-position, 2,6-position or 2,7-position; The number-average molecular weight of the polymer is 15 - 50 kDa, the weight-average molecular weight is 20 - 60 kDa, and the dispersion index is 1.2 - 3.

2. The preparation method of a polyarylether polymer based on tetraphenylethylene and its derivatives according to claim 1, characterized in that Comprising the following steps: Step 1: Respectively add a catalyst, a monomer compound of formula (Ⅱ) structure, and a monomer compound of formula (Ⅲ) structure into a low-boiling solvent. After stirring at low temperature, pour the reaction mixture into hydrochloric acid, and perform post-treatment on the reaction product to obtain a product with the structure of formula (Ⅳ); Step 2: Respectively add the monomer compound of formula (Ⅳ) structure, the monomer compound of formula (Ⅴ) structure, and a catalyst into a medium-boiling solvent, and heat and stir; after the reaction is completed, perform post-treatment on the reaction product to obtain an intermediate product with the structure of formula (Ⅵ); Step 3: Respectively add the monomer compound of formula (Ⅵ) structure and a catalyst into a low-boiling solvent. After the reaction is completed, pour the reaction mixture into a saturated potassium carbonate aqueous solution, and perform post-treatment on the crude product to obtain an intermediate product with the structure of formula (Ⅶ); Step 4: Respectively add the monomer compound of formula (Ⅶ) structure and a catalyst into a low-boiling solvent, and stir the reaction in an ice bath; after the reaction is completed, perform post-treatment on the reaction product to obtain a prepolymer monomer with the structure of formula (Ⅷ); Step 5: Put the monomer compound of formula (Ⅷ) structure, the monomer of formula (Ⅸ) structure with a carbonyl or sulfone group, a catalyst, and a high-boiling solvent into a three-necked flask equipped with a nitrogen inlet, a condenser, and a mechanical stirrer. Mechanically stir the mixture. After heating for 11 hours, the viscosity of the system begins to increase; stop the reaction, cool to room temperature, and pour the polymer solution into distilled water; finally, pulverize, filter, wash, and dry the solid obtained from the reaction to obtain a polymer containing optoelectronic functional groups.

3. The preparation method of a polyarylether polymer based on tetraphenylethylene and its derivatives according to claim 2, characterized in that: In step 1, the molar ratio of the monomer of formula (Ⅱ) structure, the monomer of formula (Ⅲ) structure, and the catalyst is 1:1:(1 - 2); In step 2, the molar ratio of the catalyst, the monomer of formula (Ⅳ) structure, and the monomer of formula (Ⅴ) structure is 1:1:(1 - 1.5); In step 3, the molar ratio of the monomer of formula (Ⅵ) structure, the catalyst, and the reducing metal is 1:4:(4 - 5); In step 4, the molar ratio of the monomer of formula (Ⅶ) structure and the catalyst is 1:(5.5 - 6.5); In step 5, the molar ratio of the monomers of formula (Ⅷ) and (Ⅸ) structure, and the catalyst is 1:1:(1 - 2).

4. The preparation method of a polyarylether polymer based on tetraphenylethylene and its derivatives according to claim 2, characterized in that: The catalyst in step 1 is one of aluminum chloride, iron chloride, zinc chloride, or boron trifluoride; The catalyst in step 2 is one or more of sodium tert-butoxide, tri(dibenzylideneacetone)dipalladium, and tri-tert-butylphosphine; The catalyst in step 3 is one of titanium tetrachloride or titanium trichloride and one of magnesium, zinc, sodium and lithium; The catalyst in step 4 is one of boron tribromide or boron trifluoride; In the step 5, the catalyst is a carbonate, such as one of potassium carbonate, sodium carbonate, cesium carbonate, sodium bicarbonate, and potassium bicarbonate.

5. The method for preparing a polyarylether polymer based on tetraphenylethylene and its derivatives according to claim 2, characterized in that: In the step 1, step 3 and step 4, the low boiling point solvent includes one of dichloromethane, tetrahydrofuran and chloroform; In the step 2, the medium boiling point solvent includes one of toluene, xylene and butanol; In the step 5, the high boiling point solvent includes one of N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide and dimethyl sulfoxide.

6. The method for preparing a polyarylether polymer based on tetraphenylethylene and its derivatives according to claim 2, characterized in that: In the step 1, the reaction temperature is 0 to 30°C and the reaction time is 2 to 5 hours; In the step 2, the reaction temperature is 90 to 180° C. and the reaction time is 9 to 15 hours; The reaction temperature in step 3 is 100-120°C; the reaction time is 6-12 hours; The reaction temperature in step 4 is -5 to 0°C; the reaction time is 10 to 20 hours; The polymerization reaction temperature in step 5 is 180-205° C., and the polymerization reaction time is 18-21 hours; The reactions in step 1 to step 5 are all carried out under protective gas, and the protective gas is nitrogen or argon.

7. An electrochromic device, characterized in that, The device is a sandwich structure, and the electrochromic layer in the device is prepared from the polyarylether polymer described in claim 1.

8. An electrochromic device, characterized in that, The device is a sandwich structure, and the electrochromic layer in the device is prepared by the polyarylether polymer according to claim 1 and polymer A in proportion, and the polymer A is one of the structures represented by formula (X) or formula (XI): Wherein, n is a positive integer, indicating the degree of polymerization.

9. An electrochromic device according to claim 8, wherein, The mass ratio of the polyarylether polymer described in claim 1 to polymer A in the electrochromic layer of the device is 1:(1.5-4).

10. A method for preparing an electrochromic device according to any one of claims 7 to 9, characterized in that, The following steps are involved: Step 1: Mix the lithium perchlorate solution and the UV curing adhesive in a high boiling point solvent according to a volume ratio, and fully immerse the PVDF membrane in the solution after stirring to obtain an electrolyte layer; Step 2, dissolving a single polymer or a polymer mixture in a high boiling point solvent, filtering the solution with a filter head after dissolution, and then evenly spreading the solution on the conductive glass by spin coating, and obtaining an ITO conductive glass containing an electrochromic thin film after drying; Step 3: Place blank ITO glass and the ITO conductive glass covered with an electrochromic film prepared in step 2 on both sides of the electrolyte layer obtained in step 1, and obtain an electrochromic device after curing with ultraviolet light.

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