A poly sulfate based on 4,4'-dihydroxydiphenyl sulfide, and a preparation method and application thereof

Abstract

This invention relates to a polysulfate based on 4,4'-dihydroxydiphenyl sulfide, its preparation method, and its applications. The polysulfate is prepared using 4,4'-dihydroxydiphenyl sulfide as the core raw material. The preparation method involves dissolving 4,4'-dihydroxydiphenyl sulfide and imidazole in dichloromethane, adding tert-butyldimethylchlorosilane, reacting at room temperature for 24 hours, and then post-processing to obtain monomer 1. Alternatively, 4,4'-dihydroxydiphenyl sulfide and triethylamine are dissolved in dichloromethane, and sulfuryl fluoride gas is introduced, reacting at room temperature for 24 hours, and then post-processing to obtain monomer 2. Monomer 1 and monomer 2 are then subjected to solution polymerization or melt polymerization to obtain the polysulfate. The polysulfate of this invention exhibits high crystallinity and excellent electrical storage performance; the preparation process is simple and easy to control, and the cost is low; when used as an active material, the ITO / polysulfate / Al sandwich structure device exhibits non-volatile WORM-type storage characteristics.

Description

Technical Field

[0001] This invention relates to the field of polymer materials and electronic devices, and in particular to a polysulfate based on 4,4'-dihydroxydiphenyl sulfide, its preparation method, and its application. Background Technology

[0002] With the rapid development of information technology, the demand for high-performance electrical storage materials is increasing. Traditional silicon-based materials have limitations in flexible electronics applications, while organic polymer materials have attracted attention due to their advantages such as strong designability and good flexibility. Against the backdrop of the global energy transition, electrochemical energy storage technology has become increasingly important, but traditional inorganic materials suffer from limited resources and complex preparation, prompting a shift in research towards green organic polymer materials.

[0003] Polyester materials, as an important category of polymers, have been widely used in many fields; however, conventional polyesters have insufficient electrical properties, making it difficult to meet the requirements of high-performance devices. Sulfur-containing polymers have become a research hotspot due to their unique electronic structure. The introduction of sulfur atoms can enhance the electron delocalization effect and improve charge transport efficiency. Polysulfate, as an important branch of sulfur-containing polymers, has excellent thermal and chemical stability, but its synthesis methods are usually cumbersome, with low yields, and its electrical storage performance is still under-studied.

[0004] Currently, polysulfate materials face challenges such as optimizing synthesis processes, precisely controlling molecular weight, and in-depth research into their electrical storage mechanisms. In particular, the application of polysulfates based on the 4,4-dihydroxydiphenyl sulfide structure in non-volatile memory urgently needs exploration. These materials, combining the advantages of thioether bonds and sulfate groups, show great promise in flexible electronics, wearable devices, and other fields; however, more efficient and controllable synthesis methods need to be developed, and their electrical storage performance needs to be systematically evaluated. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a polysulfate based on 4,4'-dihydroxydiphenyl sulfide, its preparation method, and its application. The prepared polysulfate exhibits high crystallinity and excellent electrical storage performance. The preparation process is simple, easy to control, and inexpensive. The ITO / polysulfate / Al sandwich structure device prepared using polysulfate as the active material has non-volatile WORM-type storage characteristics.

[0006] The first aspect of this invention provides a polysulfate based on 4,4'-dihydroxydiphenyl sulfide, the structural formula of which is:

[0007] ;

[0008] Where n>1.

[0009] In this invention, the thioether bond (-S-) of 4,4'-dihydroxydiphenyl sulfide conjugates with the benzene ring to enhance electron delocalization, thereby improving the conductivity of the polysulfate material; the sulfate bond (-O-SO2-) provides polar sites, increases the electrolyte contact area, and accelerates ion transport; the synergistic effect of the conjugated backbone and the thioether / sulfate groups endows the material with high pseudocapacitance (reversible redox reaction of thioether) and double-layer capacitance (charge storage of the conjugated backbone).

[0010] Preferably, the polysulfate is polymerized from monomer 1 and monomer 2; wherein, the structural formula of monomer 1 is:

[0011] ;

[0012] The structural formula of monomer 2 is:

[0013] .

[0014] Preferably, both monomer 1 and monomer 2 are synthesized based on 4,4'-dihydroxydiphenyl sulfide; the structural formula of 4,4'-dihydroxydiphenyl sulfide is:

[0015] .

[0016] A second aspect of the present invention provides a method for preparing a polysulfate based on 4,4'-dihydroxydiphenyl sulfide, comprising the following steps:

[0017] S1. 4,4'-dihydroxydiphenyl sulfide and imidazole were dissolved in dichloromethane, tert-butyldimethylchlorosilane was added, and the mixture was reacted at room temperature for 24 hours. After post-treatment, monomer 1 was obtained.

[0018] S2. 4,4'-dihydroxydiphenyl sulfide and triethylamine were dissolved in dichloromethane, and sulfuryl fluoride gas was introduced. The reaction was carried out at room temperature for 24 hours. After post-treatment, monomer 2 was obtained.

[0019] S3. Monomer 1 and monomer 2 are subjected to solution polymerization or melt polymerization in the presence of a catalyst to obtain the polysulfate;

[0020] Among them, monomer 1 is:

[0021] ;

[0022] Monomer 2 is:

[0023] .

[0024] Preferably, in step S1, the molar ratio of 4,4'-dihydroxydiphenyl sulfide, imidazole, and tert-butyldimethylchlorosilane is 1:2.5:2.5; and the reaction temperature is 20-30℃.

[0025] Preferably, the post-processing method in step S1 is as follows: remove dichloromethane by vacuum distillation; dissolve in ethyl acetate, and wash successively with deionized water, saturated NaHCO3 solution and NaCl solution; purify by column chromatography.

[0026] Preferably, in step S2, the molar ratio of 4,4'-dihydroxydiphenyl sulfide to triethylamine is 1:2.5; and the amount of sulfuryl fluoride gas introduced is 1.1 to 1.3 times the system pressure.

[0027] Preferably, in step S3, the molar ratio of monomer 1 to monomer 2 is 1:1; the catalyst is DBU, and the amount used is 20 mol% of the total amount of monomer 1 and monomer 2; the polymerization temperature is 20–130 °C; and the reaction time is 1–24 hours.

[0028] In this invention, 4,4'-dihydroxydiphenyl sulfide (BB-type monomer, symmetrical bisphenol structure) and AA monomer containing sulfur acyl fluoride (-SO2F) are used as raw materials. The reaction is carried out by DBU catalytic polycondensation under mild reaction conditions (no need for high temperature and high pressure) and high yield (up to 90%). The post-processing only requires methanol precipitation, avoiding complex purification, and realizing the controllable synthesis of high molecular weight polysulfate.

[0029] A third aspect of the present invention provides the application of a polysulfate based on 4,4'-dihydroxydiphenyl sulfide in an electrical storage device.

[0030] Preferably, polysulfate is used as an active layer material in ITO / polysulfate / Al sandwich structure devices.

[0031] Advantages of this invention: The polysulfate based on 4,4'-dihydroxydiphenyl sulfide of this invention not only has high crystallinity but also excellent electrostorage performance, relatively stable physicochemical properties, and excellent thermal stability and film-forming properties, making it promising for high-performance flexible / large-scale energy storage and green electrochemical devices. Through an efficient click chemistry synthesis pathway, the controllable preparation of high molecular weight polysulfate with a narrow molecular weight distribution is achieved, with yields exceeding 90% in each step. The mild SuFEx reaction system eliminates the need for heavy metal catalysts, conforming to green chemistry principles. The process is simple and easy to control, requires simple equipment, uses inexpensive and readily available raw materials, has low preparation costs, and offers high economic benefits, making it suitable for industrial-scale production. Attached Figure Description

[0032] Figure 1 The 1H NMR spectrum of monomer 1 in Example 1;

[0033] Figure 2 The 1H NMR spectrum of monomer 2 in Example 1;

[0034] Figure 3The image shows the 1H NMR spectrum of the polysulfate prepared in Example 1.

[0035] Figure 4 The 1H NMR spectrum of the polysulfate prepared in Example 2;

[0036] Figure 5 The TGA image of the polysulfate prepared in Example 1;

[0037] Figure 6 This is a morphology image of the polysulfate film prepared in Example 1 after film formation;

[0038] Figure 7 This is a roughness diagram of the polysulfate film prepared in Example 1 after film formation;

[0039] Figure 8 The image shows the IV curve of the ITO / polysulfate / Al sandwich device prepared using the polysulfate obtained in Example 1. Detailed Implementation

[0040] To enhance understanding of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain the invention and do not limit the scope of protection of the invention.

[0041] Example 1

[0042] This embodiment provides a polysulfate based on 4,4'-dihydroxydiphenyl sulfide, with the following structural formula:

[0043] ;

[0044] Where n>1.

[0045] In this embodiment, polysulfate is composed of a thioether-benzene ring conjugated backbone and a sulfate bond, thus exhibiting high crystallinity and excellent electrical storage performance. As a polymer material, it has promising prospects for use in flexible / large-scale energy storage and green electrochemical devices.

[0046] In this embodiment, polysulfate has high crystallinity and excellent electrical storage performance, which can be used to improve the storage density and response speed of electrical storage devices, and has high reliability.

[0047] This embodiment also provides a method for preparing polysulfate based on 4,4'-dihydroxydiphenyl sulfide, including the following steps:

[0048] Preparation of S1 and monomer 1

[0049] In a 250 mL beaker, 2.18 g (0.01 mol) of 4,4'-dihydroxydiphenyl sulfide, 1.70 g (0.025 mol) of imidazole, and 100 mL of dichloromethane were mixed thoroughly. After stirring continuously for 30 minutes, 3.77 g (0.025 mol) of tert-butyldimethylchlorosilane was slowly added to the system, and the reaction was continued for 24 hours. After the reaction was completed, the dichloromethane was removed by vacuum distillation, and the remaining product was dissolved in 40 mL of ethyl acetate. Subsequently, the product was washed successively with deionized water, saturated NaHCO3 aqueous solution, and NaCl aqueous solution. Finally, the product was concentrated by vacuum distillation and purified by column chromatography to obtain a white solid (monomer 1) with a yield of 91%.

[0050] The structural formula of monomer 1 is:

[0051] .

[0052] The reaction formula for synthesizing monomer 1 is:

[0053] .

[0054] The 1H NMR spectrum of monomer 1 is as follows Figure 1 As shown, 1 H NMR (400 MHz, DMSO) δ 7.21 (d, J = 8.3Hz, 4H), 6.84 (d, J = 8.3 Hz, 4H), 0.94 (s, 18H), 0.18 (s, 12H).

[0055] from Figure 1 The typical doublet (δ 7.2 / 6.8 ppm) of the disubstituted benzene ring and the methyl singlet of the TBS protecting group (Si-CH3 δ -0.18 ppm, C-CH3 δ 0.94 ppm) can be clearly observed, proving that the monomer structure is complete; the spectrum is free of impurity peaks, the structure is regular, and it has high chemical purity.

[0056] Preparation of S2 and monomer 2

[0057] In a 1000 mL single-necked flask, 2.18 g (0.01 mol) of 4,4'-dihydroxydiphenyl sulfide, 2.53 g (0.025 mol) of triethylamine, and 50 mL of dichloromethane were added sequentially. After vacuum filtration, sulfuryl fluoride (SO2F2) gas was introduced, and the reaction was carried out under continuous stirring for 24 hours. After the reaction was completed, dichloromethane was removed by vacuum distillation, and the remaining product was dissolved in 50 mL of ethyl acetate. Subsequently, the product was washed sequentially with HCl, NaHCO3, and NaCl solutions, concentrated by vacuum distillation again, and purified by column chromatography to finally obtain a white powder product (monomer 2) with a yield of 94%.

[0058] The structural formula of monomer 2 is:

[0059] .

[0060] The reaction formula for synthesizing monomer 2 is:

[0061] .

[0062] The 1H NMR spectrum of monomer 2 is as follows Figure 2 As shown, 1 H NMR (400 MHz, DMSO) δ 7.63 (d, J = 7.1Hz, 4H), 7.56 (d, J = 7.9 Hz, 4H).

[0063] from Figure 2 Multiple peaks (δ 7.55-7.64 ppm) were clearly observed in the anthraquinone ring hydrogens, while single peaks were observed for the methoxy and methylene groups, indicating successful synthesis. The spectrum was free of impurity peaks, had a regular structure, and possessed high chemical purity.

[0064] S3. Preparation of polysulfate (solution polymerization)

[0065] Monomer 1 obtained in step S1 and monomer 2 obtained in step S2 were polymerized at room temperature in the organic solvent N-methylpyrrolidone (NMP). The amount of catalyst 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was 20 mol% of the monomers, and the polymerization time was 24 hours. After polymerization, the reaction solution was dropped into methanol to precipitate a white powder (polysulfate, designated as P-1), with a yield of 95%.

[0066] The structural formula of P-1 is:

[0067] .

[0068] The reaction formula for synthesizing P-1 is:

[0069] .

[0070] The 1H NMR spectrum of P-1 is as follows: Figure 3 As shown, 1 ¹H NMR (400 MHz, DMSO) δ 7.48 (s, 8H). From Figure 3 As can be observed, a sharp singlet (s) is present at δ 7.48 with an integral area of ​​8H, corresponding to the aromatic ring proton signal. The singlet indicates that the chemical environment of all aromatic ring protons is completely consistent, proving that the polymer backbone structure is regular and without branching or defects. The absence of impurity peaks (such as the absence of alkyl proton signals at δ 0-5 ppm) indicates that the product has high purity and that the precipitation step effectively removed unreacted monomers or solvents.

[0071] Example 2

[0072] The difference between this embodiment and Embodiment 1 is that:

[0073] S3. Preparation of polysulfate (melt polymerization)

[0074] Monomer 1 obtained in step S1 and monomer 2 obtained in step S2 were heated to 130°C. 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), accounting for 20 mol% of the total monomers, was added to the molten monomers as a catalyst, and the reaction was continued for 1 hour. After the polymerization reaction was completed, the reaction solution was added dropwise to methanol to precipitate a white powder (polysulfate, designated as P-2), with a yield of 93%.

[0075] The reaction formula for synthesizing P-2 is:

[0076] .

[0077] P-2 1 H NMR such as Figure 4 As shown, 1 ¹H NMR (400 MHz, DMSO) δ 7.48 (s, 8H). From Figure 4 A single peak (8H) can be observed at δ 7.48, with a sharp signal and a stable baseline; compared with Figure 3 The spectra of P-1 shown are almost identical, proving that the products obtained by the two polymerization methods have the same chemical structure, further verifying the reliability of the polymerization path; the high temperature of melt polymerization did not cause the proton signal of the aromatic ring to shift or split, indicating that the polymer has good thermal stability and no significant degradation; the 93% yield and the high signal-to-noise ratio and no impurity peaks in the spectrum corroborate each other, reflecting a high degree of completion of the polymerization reaction.

[0078] from Figure 3 and Figure 4Furthermore, it can be observed that the 3.3 ppm (single peak) and 2.50 ppm (single peak) are substituent hydrogens, and the weak peak at 0.00 ppm is a residual impurity. The peak shapes and chemical shifts of the two graphs are highly consistent, with no impurity peaks, indicating that the two polysulfates have the same core structure and regular aromatic ring environment, with only differences in molecular weight distribution. This verifies the reliability of the synthesis route and provides structural basis for the study of electrical storage performance.

[0079] The polysulfate P-1 from Example 1 was subjected to TGA testing, and the results are as follows: Figure 5 As shown, from Figure 5 It can be clearly observed that from room temperature to around 318℃, the weight decreases slowly, indicating the removal of small amounts of low-boiling-point components or adsorbed water; after 318℃, the curve drops sharply, representing the rapid thermal decomposition stage of the polymer's main structure; the weight stabilizes in the 350–400℃ range, with a residual weight of approximately 65%, indicating thermally stable residues (such as inorganic matter and carbonaceous materials) after high-temperature decomposition. The curve reflects that polysulfate P-1 initially has good thermal stability, but undergoes violent thermal decomposition after 318℃. Figure 5 It can be seen that the thermal decomposition temperature (weight fraction loss of 5%) of polysulfate P-1 is 318℃, indicating that this polymer material has good thermal stability and is suitable for use as an electrical storage material.

[0080] Polysulfate P-1 from Example 1 was added to cyclohexanone to form a solution. This solution was then spin-coated onto the surface of ITO glass to form a polysulfate film. The morphology of the film was characterized, and the results are as follows: Figure 6 and Figure 7 As shown; Figure 6 The surface morphology of the polysulfate P-1 film is shown. Figure 7 The surface roughness of the polysulfate P-1 film was demonstrated; from Figure 6 and Figure 7 As can be observed, the polysulfate P-1 film exhibits a disordered molecular aggregation state with a surface roughness of only 0.38 nm, indicating that the P-1 film has high flatness, which is beneficial for the subsequent fabrication and testing of devices.

[0081] The molecular weight and molecular weight distribution of the polysulfate prepared in Examples 1 and 2 were determined using gel permeation chromatography (GPC). The specific steps are as follows: To ensure the polymer solution to be tested is clear and transparent, the polysulfate was prepared into a 2 mg / mL DMF solution and filtered using a filter membrane before testing (Note: the mobile phase of the instrument is DMF); the measurement results are shown in the table below:

[0082]

[0083] As shown in the table above, the P-1 polymer prepared by solution polymerization had an eluent time of 27.181 minutes, a number-average molecular weight (Mn) of 31.452 kDa, a weight-average molecular weight (Mw) of 42.636 kDa, and a molecular weight distribution (PDI) of 1.356; while the P-2 polymer prepared by melt polymerization had an eluent time of 27.730 minutes, a number-average molecular weight (Mn) of 26.777 kDa, a weight-average molecular weight (Mw) of 37.469 kDa, and a molecular weight distribution (PDI) of 1.399. The analysis indicates that the polysulfate obtained by solution polymerization has a larger molecular weight and a narrower molecular weight distribution than that obtained by melt polymerization, which may be related to the viscosity of the system during polymerization.

[0084] Application examples

[0085] ITO / polysulfate / Al sandwich devices were fabricated using the polysulfate (P-1) prepared in Example 1. Electrical performance tests were performed on the ITO / P-1 / Al devices, and the IV curves are shown below. Figure 8 As shown; during the initial 0 to -5V voltage sweep (sweep 1), when the voltage drops to -1.8V, the device current exhibits a sharp jump, with the ON / OFF current ratio reaching 10. 5 This indicates that the device successfully transitions from a low-conductance OFF state to a high-conductance ON state, a process that can be analogized to information writing behavior. In subsequent tests, during the second 0-5V negative voltage scan (sweep 2), the third 0-5V positive scan (sweep 3), and the fourth 0-5V negative scan (sweep 4), the device remained in the ON state and did not return to the initial OFF state. These experimental results fully demonstrate that the ITO / P-1 / Al device exhibits typical non-volatile WORM-type memory characteristics.

[0086] The polysulfate of this invention can be used to prepare organic resistive memory devices, which are suitable for wearable devices. The raw materials are readily available and low in cost, and the polymerization method is suitable for large-scale production. It provides a low-cost, high-performance candidate material for large-scale organic resistive memory applications, and promotes the development of new organic semiconductor memory materials.

[0087] The polysulfate preparation method of this invention combines high yield (90%), simple post-processing (methanol precipitation purification) and structural controllability (precise control of molecular weight by adjusting monomer ratio / catalyst dosage). Furthermore, the sulfate bond and conjugated backbone endow the material with excellent stability (resistance to photothermal hydrolysis). At the same time, relying on low-toxicity solvents (NMP, methanol), atom economy (HF removal only), and low catalyst dosage (total <3%), it practices the concept of green synthesis, laying a solid foundation for the large-scale preparation of high-performance polysulfate and its downstream applications such as photocatalysis and electrostorage.

[0088] The above embodiments should not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent conversion fall within the protection scope of the present invention.

Claims

1. A polysulfate based on 4,4'-dihydroxydiphenyl sulfide, characterized in that, Its structural formula is: ； Where n>1.

2. The polysulfate based on 4,4'-dihydroxydiphenyl sulfide according to claim 1, characterized in that, The polysulfate is polymerized from monomer 1 and monomer 2; The structural formula of monomer 1 is as follows: ； The structural formula of monomer 2 is: 。 3. The polysulfate based on 4,4'-dihydroxydiphenyl sulfide according to claim 2, characterized in that, Both monomer 1 and monomer 2 were synthesized based on 4,4'-dihydroxydiphenyl sulfide; the structural formula of 4,4'-dihydroxydiphenyl sulfide is: 。 4. A method for preparing a polysulfate based on 4,4'-dihydroxydiphenyl sulfide as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. 4,4'-dihydroxydiphenyl sulfide and imidazole were dissolved in dichloromethane, tert-butyldimethylchlorosilane was added, and the mixture was reacted at room temperature for 24 hours. After post-treatment, monomer 1 was obtained. S2. 4,4'-dihydroxydiphenyl sulfide and triethylamine were dissolved in dichloromethane, and sulfuryl fluoride gas was introduced. The reaction was carried out at room temperature for 24 hours. After post-treatment, monomer 2 was obtained. S3. Monomer 1 and monomer 2 are subjected to solution polymerization or melt polymerization to obtain the polysulfate; Among them, monomer 1 is: ； Monomer 2 is: 。 5. The method for preparing a polysulfate based on 4,4'-dihydroxydiphenyl sulfide according to claim 4, characterized in that, In step S1, the molar ratio of 4,4'-dihydroxydiphenyl sulfide, imidazole, and tert-butyldimethylchlorosilane is 1:2.5:2.5; the reaction temperature is 20-30℃.

6. A method for preparing a polysulfate based on 4,4'-dihydroxydiphenyl sulfide according to claim 4 or 5, characterized in that, The post-processing method for step S1 is as follows: remove dichloromethane by vacuum distillation; dissolve in ethyl acetate, and wash successively with deionized water, saturated NaHCO3 solution and NaCl solution; purify by column chromatography.

7. The method for preparing a polysulfate based on 4,4'-dihydroxydiphenyl sulfide according to claim 4, characterized in that, In step S2, the molar ratio of 4,4'-dihydroxydiphenyl sulfide to triethylamine is 1:2.5; the amount of sulfuryl fluoride gas introduced is 1.1 to 1.3 times the system pressure.

8. The method for preparing a polysulfate based on 4,4'-dihydroxydiphenyl sulfide according to claim 4, characterized in that, In step S3, a catalyst was also added to the polymerization reaction; the catalyst was DBU, and the amount used was 20 mol% of the total monomer; the polymerization temperature was 20–130 °C; and the reaction time was 1–24 hours.

9. An application of a polysulfate based on 4,4'-dihydroxydiphenyl sulfide in electrical storage devices.

10. The application of a polysulfate based on 4,4'-dihydroxydiphenyl sulfide according to claim 9, characterized in that, Application of polysulfate as active layer material in ITO / polysulfate / Al sandwich structure devices; the device has non-volatile WORM-type storage characteristics.

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