Crosslinkable thiophene-based polymer, preparation method thereof, and crosslinked film

Abstract

The present invention belongs to the field of polymer materials and specifically relates to a cross-linkable thiophene-based polymer, a preparation method thereof, and a cross-linked film prepared using the same. The cross-linkable thiophene-based polymer is obtained by Still coupling a monomer containing a cross-linkable functional group with a monomer having photocatalytic properties. The cross-linkable thiophene-based polymer undergoes a cross-linking reaction of the functional groups under illumination or heating conditions, forming a cross-linked film with excellent stability, resistance to solvent corrosion, and acid and alkali resistance. The film can be used to reduce harmful substances in wastewater.

Description

Technical Field

[0001] The present invention belongs to the field of polymer materials, and in particular relates to a cross-linkable thiophene-based polymer and a preparation method thereof, as well as a cross-linked film prepared using the same and its application in photocatalytic reduction of uranium (VI). Background Art

[0002] The treatment of radioactive wastewater is a major challenge facing the rare earth industry, the nuclear energy industry, and nuclear facility operations. Uranium-containing wastewater, a highly toxic and radioactive type, poses a particular urgency due to its potential harm to the environment and human health. Traditional wastewater treatment methods, such as precipitation, adsorption, and ion exchange, suffer from low efficiency, high treatment costs, and secondary pollution. Therefore, the development of new, efficient, and environmentally friendly wastewater treatment technologies is urgently needed.

[0003] As an emerging wastewater treatment method, photocatalytic technology has attracted widespread attention due to its advantages such as high efficiency, no need to add chemical reagents, and no secondary pollution. During the photocatalytic process, the photocatalyst produces active oxides or electron-hole pairs through light energy absorption and conversion, thereby catalyzing the redox reaction of harmful substances. The problems faced by the current method of photocatalytic reduction of uranium to treat wastewater mainly include the narrow absorption spectrum of the material, low catalytic reduction efficiency, and difficulty in recovering the catalyst. CN116078415A discloses a method for preparing a mesoporous titanium dioxide photocatalyst for photocatalytic reduction of uranium. The method adopts a combination of element doping and surface functional modification to improve the utilization range of visible light and the selectivity for uranium. Despite this, its maximum absorption wavelength is only about 700nm, which still cannot cover the entire visible light region; compared with inorganic compounds, the spectral absorption range, energy level, and band gap of organic compounds are easier to adjust. CN113045723A discloses a method for preparing a porous covalent organic framework and its application in capturing uranyl ions. The organic framework has an initial absorption wavelength of up to 900 nm, covering the entire visible light region. However, because the organic framework acts directly in water, it is difficult to recover and can easily cause secondary pollution. CN114931862A discloses a photothermal photocatalytic membrane for seawater desalination and uranium extraction and its preparation method. The film preparation includes polyacrylonitrile, nano-titanium dioxide, macromolecular additives, inorganic salt additives, etc. This method is relatively complex to prepare, and the film formed after the material is formed has poor strength and is prone to cracking under acidic and alkaline conditions.

[0004] Therefore, how to provide an organic material with a wide light absorption range, good acid and alkali resistance, high strength, and easy recycling is a problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] In light of this, the present invention provides a cross-linkable thiophene-based polymer with a novel structure and a broad light absorption range. This polymer is prepared into a thin film using a Czochralski-impregnation method and then cross-linked by heating or light irradiation. The cross-linked film exhibits advantages such as excellent acid and alkali resistance, high strength, easy recycling, a large specific surface area, and strong light absorption. It can be used for the photocatalytic reduction of uranium-containing wastewater, achieving efficient removal of uranium (VI) ions from the wastewater.

[0006] The technical solution of the present invention:

[0007] The first technical problem to be solved by the present invention is to provide a cross-linkable thiophene-based polymer, the structural formula of the cross-linkable thiophene-based polymer is shown in Formula I:

[0008]

[0009] Among them, R0 contains a cross-linkable functional group, and Ar is an aromatic fused heterocyclic group.

[0010] Furthermore, in the cross-linkable thiophene-based polymer, m is any integer from 5 to 40. Preferably, m is any integer from 8 to 12.

[0011] Specifically, in the cross-linkable thiophene polymer, the cross-linkable functional group is a bromine group, a vinyl group or an oxetane group.

[0012] Furthermore, in the above cross-linkable thiophene-based polymer, R0 is Each n is independently any integer from 1 to 20. Preferably, each n is independently any integer from 5 to 9.

[0013] Specifically, in the above cross-linkable thiophene polymer, Ar is

[0014] Wherein, each R1 and R2 are independently C 1-20 Preferably, each R1 and R2 are independently C 6-12 Straight-chain or branched-chain alkyl.

[0015] The second technical problem to be solved by the present invention is to provide a method for preparing the cross-linkable thiophene polymer. The preparation method comprises the following steps: Prepared by Still coupling reaction, wherein R0 contains a cross-linkable functional group.

[0016] Furthermore, in the above preparation method, the dibrominated aromatic compound is

[0017]

[0018] Wherein, each R1, R2 is independently selected from C 1-20 Preferably, each R1 and R2 are independently selected from C 6-12 Straight-chain or branched-chain alkyl.

[0019] Furthermore, in the above preparation method, the cross-linkable functional group is a bromo group, a vinyl group or an oxetane group. Each n is independently any integer from 1 to 20. Preferably, each n is independently any integer from 5 to 9.

[0020] Furthermore, in the above preparation method, when R0 is hour, The preparation method comprises the following steps: (Compound A) was prepared by Grignard reaction (Compound B), compound B and 3-bromothiophene are reacted in the presence of a catalyst to prepare (Compound C), compound C and trimethyltin chloride react under the action of a catalyst to obtain (Compound F).

[0021] Furthermore, the catalyst used in preparing compound C is Ni(dppp)2Cl2. The reaction temperature for preparing compound C is 0-25°C, preferably 0°C. The reaction time is 10-16 hours. The solvent used in the reaction is tetrahydrofuran.

[0022] Furthermore, the catalyst used in preparing Compound F is n-butyl lithium. The reaction temperature for preparing Compound F is room temperature. The reaction time is 10 to 20 hours. The solvent used in the reaction is tetrahydrofuran. Furthermore, Compound C is first dissolved in a solvent, cooled to -78°C, and then the catalyst is added. After warming to room temperature, trimethyltin chloride is added to react.

[0023] Furthermore, in the above preparation method, when R0 is hour, The preparation method comprises the following steps: Compound C is reacted in the presence of a catalyst to obtain (Compound D), compound D and trimethyltin chloride react under the action of a catalyst to obtain (Compound G).

[0024] Furthermore, the catalyst used in the preparation of compound D is potassium tert-butoxide, the reaction temperature is room temperature (20° C.), the reaction time is 10 to 20 hours, and the solvent used in the reaction is ethanol.

[0025] Furthermore, the catalyst used in preparing Compound G is n-butyl lithium. The reaction temperature for preparing Compound G is room temperature. The reaction time is 10 to 20 hours. The solvent used in the reaction is tetrahydrofuran. Furthermore, Compound D is first dissolved in a solvent, cooled to -78°C, and then the catalyst is added. After warming to room temperature, trimethyltin chloride is added to react.

[0026] Furthermore, in the above preparation method, when R0 is hour, The preparation method comprises the following steps: 3-methyl-3-hydroxymethyloxetane and tetrabutylammonium bromide react with compound C in the presence of an alkaline reagent to prepare (Compound E); Compound E and trimethyltin chloride react under the action of a catalyst to obtain (Compound H).

[0027] Furthermore, the alkaline reagent used in preparing compound E is sodium hydroxide. The reaction temperature is reflux. The reaction time is 4 to 6 hours. The solvent used in the reaction is n-hexane.

[0028] Furthermore, the catalyst used in preparing Compound H is n-butyl lithium. The reaction temperature for preparing Compound H is room temperature. The reaction time is 10 to 20 hours. The solvent used in the reaction is tetrahydrofuran. Furthermore, Compound E is first dissolved in a solvent, cooled to -78°C, and then the catalyst is added. After warming to room temperature, trimethyltin chloride is added to react.

[0029] The third technical problem to be solved by the present invention is to provide a crosslinkable thiophene-based polymer film. The crosslinkable thiophene-based polymer film is prepared from the crosslinkable thiophene-based polymer described above. For example, the crosslinkable thiophene-based polymer (i.e., material P1) is dissolved in an organic solvent and formed into a film on a substrate by a pulling and dipping method. The substrate may be glass or a polymer matrix. The organic solvent may be chloroform, chlorobenzene, tetrahydrofuran, or xylene.

[0030] The fourth technical problem to be solved by the present invention is to provide a cross-linked film. The cross-linked film is prepared by irradiating or heating the cross-linkable thiophene-based polymer film. For example, the cross-linkable thiophene-based polymer film is irradiated with ultraviolet light for 1 hour or heated at 130°C for 20 minutes.

[0031] The fifth technical problem to be solved by the present invention is to provide a method for reducing hexavalent uranium to tetravalent uranium using the cross-linked film. The cross-linked film is used to treat uranium-containing wastewater and can reduce soluble hexavalent uranium to less soluble tetravalent uranium.

[0032] Beneficial effects of the present invention:

[0033] The present invention provides a cross-linked thiophene-based polymer with a novel structure. Cross-linked films prepared from this polymer exhibit advantages such as good stability, resistance to solvent corrosion, a wide light absorption range, strong acid and alkali resistance, high strength, and easy recycling. These films can be used for the photocatalytic reduction of uranium-containing wastewater, converting hexavalent soluble uranium into less soluble tetravalent uranium. This allows for efficient removal of uranium ions from wastewater, thereby reducing environmental pollution and harm. Compared to powdered materials, films prepared from this cross-linked thiophene-based polymer can be fabricated to maximize their utilization by controlling film thickness.

[0034] The present invention introduces crosslinkable functional groups into a conjugated polymer to achieve crosslinking of the film material, thereby improving the film's stability and durability, resulting in a longer service life. Furthermore, the crosslinked film exhibits excellent photocatalytic properties, requiring significantly less material than solid powders. A catalytic amount of the film alone can efficiently reduce uranium ions in uranium-containing wastewater. Furthermore, the crosslinked film exhibits resistance to solvent corrosion and acid and alkali resistance, enabling stable operation in a variety of solvent environments, providing greater flexibility and adaptability for practical applications. Furthermore, compared to traditional photocatalytic solid materials, the film material offers advantages such as ease of recycling and no secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is the thermogravimetric curve of compound 4 obtained in the embodiment of the present invention; Figure 1 It can be seen that the material synthesized by the present invention has good thermal stability and will not undergo thermal decomposition below 300°C.

[0036] Figure 2 This is a photo of a cross-linkable film attached to a glass substrate prepared according to an embodiment of the present invention.

[0037] Figure 3 is the efficiency of photocatalytic removal of uranium-containing wastewater by compound 4 obtained in Example 1 of the present invention at different pH values; Figure 3 It can be seen that the thin film material synthesized by the present invention has obvious effects in a wide pH range. When the pH is 5, the photocatalytic removal efficiency can reach 85%. Among them, the vertical axis C / C0, C represents the uranium concentration at different times, and C0 is the initial uranium concentration.

[0038] Figure 4 is the UV-visible absorption spectrum of compound 4 obtained in Example of the present invention; Figure 4 It can be seen that the synthesized material of the present invention has a wide light absorption range and can utilize sunlight to the greatest extent, and its maximum absorption wavelength reaches 850nm. DETAILED DESCRIPTION

[0039] The present invention copolymerizes the thiophene-containing and cross-linkable functional group units with the ADA-type small molecule structural units to realize the construction of the conjugated polymer, expand its electron delocalization range, and improve the carrier mobility; CL The ADA polymer is dissolved in a chloroform / chlorobenzene solution and formed into a thin film on a substrate by drawing and impregnation. Under ultraviolet light or heating, the crosslinkable functional groups in the prepared film are crosslinked, forming a crosslinked film with excellent stability, resistance to solvent corrosion, acid and alkali resistance, and photocatalytic properties. This crosslinked film is used for the photocatalytic reduction of uranium-containing wastewater, which can reduce the uranium ion concentration in the wastewater, reduce the harm caused by uranium-containing wastewater, and ensure that it meets emission standards.

[0040] The cross-linkable thiophene-based polymer of the present invention has a structural formula as shown in Formula I:

[0041]

[0042] Wherein, the thienyl 3-position substituent R0 contains a crosslinkable functional group, and the Ar monomer polymerized with the thienyl monomer is an aromatic fused heterocyclic compound. m is any integer from 5 to 40. Preferably, m is any integer from 8 to 12. The crosslinkable functional group is a bromo group, a vinyl group or an oxetane group. The R0 is Each n is independently any integer from 1 to 20. Preferably, each n is independently any integer from 5 to 9. Ar is

[0043] Wherein, each R1 and R2 are independently C 1-20 Preferably, each of R1 and R2 is independently C 6-12 Straight-chain or branched-chain alkyl.

[0044] The preparation method of the cross-linkable thiophene polymer of the present invention comprises the following steps: a dibrominated aromatic compound and a cross-linkable thiophene monomer having the structural formula Prepared by Still coupling reaction.

[0045] The dibrominated aromatic compound is

[0046] Wherein, each R1 and R2 are independently C 1-20 Preferably, each of R1 and R2 is independently C 6-12 Straight-chain or branched-chain alkyl.

[0047] The cross-linkable thienyl monomer The preparation method comprises the following steps:

[0048] Step 1) containing dibromoalkane compound A In the presence of magnesium chips and iodine, the unilateral Grignard reagent B was prepared by Grignard reaction. Among them, the value of n is 1-20;

[0049] Step 2) Prepare thiophene compound C containing halogenated alkyl substituted by reacting unilateral Grignard reagent B with 3-bromothiophene in the presence of catalyst Ni(dppp)2Cl2 Further, compound B is added to a tetrahydrofuran solution containing 3-bromothiophene and 1,3-bis(diphenylphosphinopropane)nickel dichloride at 0-25° C., stirred for 10-16 hours, and purified to obtain compound C;

[0050] Step 3) Compound C is reacted with an ethanol solution of potassium tert-butoxide at room temperature (20° C.) for 10 to 20 hours, and the reaction solution is extracted, dried, and purified to obtain Compound D;

[0051] Alternatively, 3-methyl-3-hydroxymethyloxetane and tetrabutylammonium bromide are dissolved in n-hexane, and a sodium hydroxide aqueous solution (50% by mass) and compound C are added; the reaction mixture is reacted at room temperature for 30 minutes and then under reflux for 4 to 6 hours; the reaction solution is washed with water and the solvent is removed; and the crude product is purified by column chromatography to obtain compound E;

[0052] Step 4) Compound C, D or E is reacted with n-butyl lithium and trimethyltin chloride to prepare thiophene-based cross-linkable polymerizable monomer F. G H Furthermore, under nitrogen protection, compound C, D or E is dissolved in anhydrous tetrahydrofuran, cooled to -78°C, and n-butyl lithium is added dropwise. After the addition is completed, the reaction is continued for 30 minutes, and the temperature is slowly raised to room temperature and the reaction is continued for 30 minutes; then trimethyltin chloride is added dropwise. After the addition is completed, the reaction is continued at room temperature for 10-20 hours; water is added to quench the reaction, and the reaction mixture is extracted with diethyl ether three times; the organic layer is dried over magnesium sulfate, filtered, and concentrated to purify compound F, G or H as a colorless oil.

[0053] The present invention prepares the crosslinkable thiophene polymer into a 10 mmol / L chloroform solution. A 2 cm x 2 cm glass is placed in the solution, left to rest for 1 minute, then removed and air-dried. After drying, a thin film forms on the glass surface. The film-coated glass is then irradiated under ultraviolet light for 10 minutes to crosslink the film. Under illumination or heating, the crosslinkable functional groups (bromine, vinyl, or oxetane) undergo a crosslinking reaction, resulting in a high-strength, acid- and alkali-resistant crosslinked film.

[0054] The cross-linked film of the present invention is used for photocatalytic reduction of uranium-containing wastewater. A glass sheet with a cross-linked film (containing about 2 mg of polymer material) is placed in 200 mL of 50 ppm UO2 2+ The solution was reacted in the dark for 2 h to reach the adsorption-desorption equilibrium; then, after irradiation with simulated sunlight for a period of time, the sample was analyzed for UO2 at a wavelength of 650 nm. 2+ The absorbance of different irradiation times is converted into UO2 2+ removal rate.

[0055] The specific implementation methods of the present invention are further described below in conjunction with examples, but the present invention is not limited to the scope of the examples.

[0056] Example 1

[0057] Preparation of crosslinkable thiophene-based polymer P1

[0058]

[0059] (1) Synthesis of Compound 1

[0060] Under an argon atmosphere, 10 mL of THF solution was added to a round-bottom flask containing magnesium chips (25 mmol, 600 mg) and a small amount of iodine (1-2 grains). Then, a tetrahydrofuran solution (40 mL) containing 1,6-dibromohexane (20 mmol, 4.84 g) was charged into a constant pressure funnel, and 5 mL was added dropwise to the round-bottom flask. The mixture was heated with a hair dryer until the reaction was initiated (the brown color of the iodine element disappeared). Then, the remaining tetrahydrofuran solution containing 1,6-dibromohexane was added dropwise to the reaction solution (the addition was completed within about 5 minutes). After the addition was completed, the reaction solution was heated to reflux and the reaction was continued for 3 hours. After the reaction was completed, the mixture was cooled to room temperature and compound 1 was obtained without purification, which was directly used in the next step.

[0061] (2) Synthesis of Compound 2

[0062] The Grignard reagent (compound 1) generated by the above reaction was transferred to a constant pressure dropping funnel and then added dropwise to a tetrahydrofuran solution (50 mL) containing 3-bromothiophene (20 mmol, 3.3 g) and 1,3-bis(diphenylphosphinopropane)nickel dichloride (Ni(dppp)2Cl2) (50 mg) at 0°C. The mixed solution was stirred at room temperature for 12 hours, and then 50 mL of water was added to quench the reaction, and the mixture was extracted with ether. The organic layer was dried over MgSO4 and filtered, and the filtrate was concentrated by rotary evaporation to obtain a crude product; the crude product was purified by silica gel chromatography (mobile phase: petroleum ether) to obtain pure compound 2 (16 mmol, 80% yield) as a light yellow oil. 1HNMR(400MHz, CDCl3, δ / ppm):7.21-7.15(d,1H,-ArH),6.94-6.89(m,3H,-ArH),3 .35-3.11(m,2H,-CH2Br),2.92-2.84(m,2H,Ar-CH2-),2.13-2.45(m,8H,-CH2-).

[0063] (3) Synthesis of Compound 3

[0064] Under nitrogen, the prepared 3-(6-bromohexyl)thiophene (compound 2) (10 mmol, 2.5 g) was dissolved in 25 mL of anhydrous tetrahydrofuran. The mixture was cooled to -78°C and 4.8 mL of n-butyllithium (12 mmol, 2.5 mol / L) was added dropwise. The reaction was continued for 30 min. After the reaction, the temperature was slowly warmed to room temperature. The reaction was continued at room temperature for 30 min, and then trimethyltin chloride (14 mmol, 2.8 g) was added dropwise. After the addition was complete, the mixture was stirred at room temperature overnight. After the reaction was completed, the reaction was quenched with water, and the reaction mixture was extracted three times with diethyl ether. The organic layer was dried over magnesium sulfate, filtered to remove the desiccant, concentrated by rotary evaporation, and purified by silica gel chromatography using a 19:1 hexane:triethylamine (volume ratio) as the eluent to obtain compound 3 as a colorless oil in approximately 80% yield. 1 H NMR (400MHz, CDCl3, δ / ppm): 3.58-3.49(m,2H,-CH2Br), 2.88-2.74(m,2H,Ar-CH2-), 2.05-1.98(m,8H,-CH2-), 0.55-0.68(m,18H,-CH3).

[0065] (4) Synthesis of polymer P1 (compound 4)

[0066] The above-obtained product (3-(6-bromohexyl)thiophene-2,5-diyl)di(trimethyl)tin (compound 3) (1 mmol, 0.57 g) and Y5-2Br (CAS: 2418532-43-9, purchased from Suzhou Nakai Technology Co., Ltd.) (1 mmol, 1.53 g) were dissolved in degassed chlorobenzene (20 mL). Under argon protection, catalyst tris(dibenzylideneacetone)dipalladium (Pd2dba3) (0.122 mmol, 112 mg) and tri(o-methylphenyl)phosphine (P(o-tol)3) (1.47 mmol, 448 mg) were added and reacted at 120°C for 12 h. After the reaction, the reaction solution was added dropwise to methanol to obtain a black solid product, which was extracted with methanol, n-hexane and acetone for 24 h respectively, and then dried to obtain 1.42 g of the product (polymer P1).

[0067] Preparation of cross-linkable thiophene-based polymer films

[0068] The polymer P1 obtained above was prepared into a 10 mmol / L chloroform solution. A 2 cm*2 cm glass prepared in advance was placed in the solution. After standing for 1 minute, it was taken out and dried. After drying, a thin film was formed on the surface of the glass. The glass with the film was irradiated under ultraviolet light for 10 minutes to cross-link the film.

[0069] Application of cross-linked films in photocatalytic reduction of uranium-containing wastewater

[0070] A 350W xenon lamp equipped with a 420nm filter was used as a visible light source, and the glass slide with the cross-linked film obtained above was placed in 200mL 50ppm UO2 2+ A solution (uranyl nitrate dissolved in a mixture of deionized water and methanol (5 mL)) was prepared; the pH of the solution was adjusted to 5 using dilute hydrochloric acid and potassium carbonate. Before irradiation, the reaction was allowed to proceed in the dark for 2 h to achieve adsorption-desorption equilibrium; then, samples were taken every 30 minutes (5.5 h) under simulated sunlight, and the samples were analyzed for UO2 at a wavelength of 650 nm. 2+ The absorbance of different irradiation times is converted into UO2 2+ The removal rate was measured to be 85%. When the pH is 4 or 6, the operation is the same as when the pH is 5 except for the different pH values.

Claims

1. A cross-linkable thiophene-based polymer, as shown in Formula I: Formula I in, R0 contains a cross-linkable functional group, which is a bromo group, a vinyl group or an oxetane group; Ar is 、 、 、 、 or ; wherein each R1 and R2 are independently C 1-20 Straight-chain or branched alkyl; m is any integer from 5 to 40.

2. The crosslinkable thiophene-based polymer according to claim 1, characterized in that: m is any integer between 8 and 12.

3. The crosslinkable thiophene-based polymer according to claim 1 or 2, characterized in that: R0 is 、 or , each n is independently any integer between 1 and 20.

4. The crosslinkable thiophene-based polymer according to claim 3, characterized in that: Each n is independently any integer from 5 to 9.

5. The cross-linkable thiophene-based polymer according to claim 1, wherein: Each R1 and R2 are independently C 6-12 Straight-chain or branched-chain alkyl.

6. The method for preparing a cross-linkable thiophene-based polymer according to claim 1, wherein: The following steps are involved: Dibromoaromatic compounds and The cross-linkable thiophene polymer is prepared by Stille coupling reaction, wherein R0 contains a cross-linkable functional group, and the cross-linkable functional group is a bromine group, a vinyl group or an oxetane group; the dibrominated aromatic compound is 、 、 、 、 or ; wherein each R1, R2 are independently selected from C 1-20 Straight-chain or branched-chain alkyl.

7. The method for preparing a cross-linkable thiophene-based polymer according to claim 6, wherein: Each R1 and R2 are independently selected from C 6-12 Straight-chain or branched-chain alkyl.

8. The method for preparing a cross-linkable thiophene-based polymer according to claim 6, wherein: R0 is 、 or , each n is independently any integer between 1 and 20.

9. The method for preparing a cross-linkable thiophene-based polymer according to claim 8, wherein: Each n is independently any integer from 5 to 9.

10. The method for preparing a cross-linkable thiophene-based polymer according to claim 8 or 9, characterized in that: When R0 is hour, The preparation method comprises the following steps: compound A Compound B was prepared by Grignard reaction Compound B reacts with 3-bromothiophene in the presence of a catalyst to prepare compound C Compound C reacts with trimethyltin chloride in the presence of a catalyst to obtain compound F. ; The catalyst used in the preparation of compound C is Ni(dppp)2Cl2; the catalyst used in the preparation of compound F is n-butyllithium; When R0 is hour, The preparation method comprises the following steps: Compound C is reacted in the presence of a catalyst to obtain Compound D Compound D and trimethyltin chloride react under the action of a catalyst to obtain compound G ; The catalyst used in the preparation of compound D is potassium tert-butoxide; the catalyst used in the preparation of compound G is n-butyl lithium; When R0 is hour, The preparation method comprises the following steps: 3-methyl-3-hydroxymethyloxetane and tetrabutylammonium bromide react with compound C in the presence of an alkaline reagent to prepare compound E Compound E reacts with trimethyltin chloride in the presence of a catalyst to obtain compound H ; The alkaline reagent used in the preparation of compound E is sodium hydroxide; the catalyst used in the preparation of compound H is n-butyl lithium.

11. A cross-linkable thiophene-based polymer film, characterized in that: The cross-linkable thiophene polymer is prepared from the cross-linkable thiophene polymer according to any one of claims 1 to 5.

12. A cross-linked film, characterized in that: The cross-linkable thiophene-based polymer film according to claim 11 is prepared by irradiating light or heating.

13. Use of the cross-linked film according to claim 12 for reducing hexavalent uranium to tetravalent uranium.

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