Thiourea-selenourea random copolymer as well as preparation method and application thereof

Abstract

The invention provides a thiourea-selenourea random copolymer as well as a preparation method and application thereof, and belongs to the technical field of polymer synthesis. According to the invention, sulfur selenide, an isonitrile compound and diamine are subjected to a multi-component polymerization reaction under a catalyst-free condition to synthesize the random copolymer containing thiourea and selenourea repetitive units. The reaction raw materials used in the method are easy to obtain or simple to prepare; the method provided by the invention has the advantages of mild reaction conditions, simple process, high efficiency and high yield, and can realize efficient synthesis of the thiourea-selenourea random copolymer. The thiourea-selenourea random copolymer prepared by the invention contains sulfur atoms and selenium atoms at the same time, so that the random copolymer has a high refractive index in a film state, and has a wide application prospect in the field of shading materials.

Description

Technical Field

[0001] The invention relates to the technical field of polymer synthesis, and in particular to a thiourea-selenourea random copolymer and a preparation method and application thereof. Background Art

[0002] Selenium has a higher electrical conductivity than sulfur. By doping or replacing part of the sulfur in sulfur-containing polymers with selenium, unexpected performance improvements can be achieved. For example, in organic Li-S batteries, selenium doping can inhibit the "shuttle effect" in Li-S batteries. Sulfur- and selenium-containing polymers have excellent application prospects in the fields of Li-S / Na-S batteries, organic solar cells, organic semiconductors, high refractive index materials, dynamic reversible materials, and biomedical materials. However, the current methods for synthesizing simultaneous sulfur- and selenium-containing polymers are very limited, mainly the following: (1) first synthesize polythiophene / selenophene monomers, and then use Stille coupling or electrochemical synthesis of conjugated polymers for solar cells or organic semiconductors; (2) blend elemental selenium and sulfur with the concept of doping, and adjust the selenium-sulfur ratio to use for Li-S / Na-S battery electrode materials; (3) elemental sulfur / selenium solid solution, and then undergo reverse sulfurization with olefins to synthesize sulfur- and selenium reverse sulfurization products; (4) dynamic disulfide bonds are exchanged with diselenide bonds to synthesize sulfur- and selenium-containing polymers with dynamic bonds, which are used in the field of dynamic materials. Among the above synthesis methods, only method (1) can obtain sulfur- and selenium-containing polymers with clear structures, but this type of reaction process is complicated and the reaction conditions are harsh. It is usually necessary to convert thiophene or selenium phenol into highly toxic organotin reagents, and the products are usually oligomers. Although the latter methods avoid the use of organotin reagents, the reaction conditions need to be carried out at high temperatures, and the obtained polymers have complex structures and are difficult to characterize. The above synthesis methods have seriously restricted the development of sulfur- and selenium-containing polymers. Summary of the invention

[0003] The purpose of the present invention is to provide a thiourea-selenourea random copolymer and a preparation method and application thereof, so as to solve the problem that the current synthesis of sulfur- and selenium-containing polymers is complicated and costly.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing a thiourea-selenourea random copolymer, comprising the following steps:

[0006] The thiourea-selenourea random copolymer is obtained by mixing the thiourea-selenourea compound, the isonitrile compound, the diamine and the organic solvent and performing a polymerization reaction in a protective atmosphere.

[0007] The sulfoselenide is selenium disulfide or selenium sulfide.

[0008] Preferably, the isonitrile compound has a structure shown in Formula 1:

[0009]

[0010] In formula 1, R 1 It is an aromatic or aliphatic group.

[0011] Preferably, the R 1 for

[0012] Preferably, the diamine has a structure shown in Formula 2 or Formula 3:

[0013]

[0014] The R 2 include:

[0015]

[0016] Preferably, when the sulfoselenide is selenium disulfide, the molar ratio of selenium disulfide, isonitrile compound and diamine is 2.0-2.3:3.0:3.0; when the sulfoselenide is selenium sulfide, the molar ratio of selenium sulfide, isonitrile compound and diamine is 1.0-1.2:1:1.

[0017] Preferably, the protective atmosphere includes nitrogen and / or argon; the organic solvent includes one or more of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, dichloromethane and chloroform.

[0018] Preferably, the concentration of the isonitrile compound in the organic solvent is 0.25 to 1 mol / L.

[0019] Preferably, the polymerization reaction temperature is 25 to 100° C. and the time is 1 to 12 hours.

[0020] The present invention provides a thiourea-selenourea random copolymer prepared by the preparation method described in the above technical scheme, which has a structure shown in Formula I or Formula II:

[0021]

[0022]

[0023] In formula I, m:n=1~2.2:1; in formula II, x:y=1~2.2:1.

[0024] The present invention provides application of the thiourea-selenourea random copolymer described in the above technical solution in the field of shading materials.

[0025] The invention provides a method for preparing a thiourea-selenourea random copolymer. The method comprises the following steps: carrying out a multi-component polymerization reaction in an organic solvent using thioselenide, an isonitrile compound and a diamine. Since the S-Se bond of the thioselenide is opened under heating conditions in the solvent to generate active reaction species, the thiourea-selenourea random copolymer can be synthesized without the action of a catalyst.

[0026] The reaction raw materials used in the preparation method of the present invention are easily available (commercially available) or are simple to prepare; the method of the present invention has mild reaction conditions, simple process, high efficiency, high yield, and can achieve efficient synthesis of thiourea-selenourea random copolymers, solving the problem of complicated steps and high cost in the current synthesis of sulfur- and selenium-containing polymers.

[0027] The preparation method of the present invention has strong group tolerance, and various functional groups (such as ether groups, thioether groups, fatty groups or aromatic rings) can be introduced into the monomer through diamine and isonitrile compounds.

[0028] The thiourea-selenourea random copolymer prepared by the invention contains sulfur atoms and selenium atoms at the same time, and thus has a high refractive index in a film state, and has broad application prospects in the field of light-shielding materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The synthetic route and NMR spectrum of polymer P1;

[0030] Figure 2 is the X-ray photoelectron spectrum of polymer P1; wherein A is the S2p and Se 3p orbital electron X-ray photoelectron spectrum of polymer P1, and B is the S2p and Se 3d orbital electron X-ray photoelectron spectrum of polymer P1;

[0031] Figure 3 is the H-NMR spectrum of polymer P2;

[0032] Figure 4 is the NMR carbon spectrum of polymer P2;

[0033] Figure 5 is the H-NMR spectrum of polymer P3;

[0034] Figure 6 is the NMR carbon spectrum of polymer P3;

[0035] Figure 7 The refractive index of the spin-coated film prepared from copolymer P1 is plotted against wavelength. DETAILED DESCRIPTION

[0036] In the present invention, unless otherwise specified, the required raw materials or reagents are commercially available products well known to those skilled in the art.

[0037] The present invention provides a method for preparing a thiourea-selenourea random copolymer, comprising the following steps:

[0038] The thiourea-selenourea random copolymer is obtained by mixing the thiourea-selenourea compound, the isonitrile compound, the diamine and the organic solvent and performing a polymerization reaction in a protective atmosphere.

[0039] The selenide sulfide is selenium disulfide (SeS2) or selenium sulfide (SeS), preferably SeS2.

[0040] In the present invention, the isonitrile compound preferably has a structure shown in Formula 1:

[0041]

[0042] In formula 1, R 1 It is an aromatic or aliphatic group.

[0043] In the present invention, the R 1 Preferably The corresponding isonitrile compound is preferably:

[0044]

[0045] In the present invention, the diamine preferably has a structure shown in Formula 2 or Formula 3:

[0046]

[0047] The R 2 include:

[0048]

[0049] In the present invention, the diamine is preferably:

[0050]

[0051]

[0052] In the present invention, when the sulfoselenide is selenium disulfide, the molar ratio of the selenium disulfide, isonitrile compound and diamine is 2.0-2.3:3.0:3.0, more preferably 2.22:3; when the sulfoselenide is selenium sulfide, the molar ratio of the selenium sulfide, isonitrile compound and diamine is 1.0-1.2:1:1.

[0053] In the present invention, the protective atmosphere preferably includes nitrogen and / or argon.

[0054] In the present invention, the organic solvent preferably includes one or more of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, dichloromethane and chloroform, and more preferably dimethyl sulfoxide (DMSO); when the organic solvent is two or more of the above, the present invention has no special limitation on the ratio of different types of organic solvents, and any ratio is acceptable.

[0055] In the present invention, the concentration of the isonitrile compound in the organic solvent is preferably 0.25 to 1 mol / L, more preferably 0.25 to 0.5 mol / L, and further preferably 0.25 mol / L.

[0056] In the present invention, the polymerization reaction temperature is preferably 25-100°C, more preferably 50-90°C, and further preferably 60-80°C; the time is preferably 1-12h, and more preferably 8-12h; the polymerization reaction is preferably carried out under stirring conditions, and the stirring speed is preferably 200-600rpm, more preferably 300-500rpm, and further preferably 400rpm.

[0057] After the polymerization reaction is completed, the present invention preferably precipitates the obtained product liquid in methanol, filters it, and dries it to obtain a thiourea-selenourea random copolymer.

[0058] The present invention provides a thiourea-selenourea random copolymer prepared by the preparation method described in the above technical scheme, which has a structure shown in Formula I or Formula II:

[0059]

[0060] In formula I, m:n=1~2.2:1; in formula II, x:y=1~2.2:1.

[0061] In the present invention, m:n=2:1 is more preferred.

[0062] In the present invention, the thiourea-selenourea random copolymer is preferably

[0063]

[0064] The present invention provides application of the thiourea-selenourea random copolymer described in the above technical solution in the field of shading materials.

[0065] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0066] Example 1

[0067] A thiourea-selenourea random copolymer, whose structural formula is shown in P1 and whose reaction formula is shown in formula (1):

[0068]

[0069] Among them, selenium disulfide 1 was purchased from McLean Chemical Company, isonitrile 2 was synthesized according to reference (JACS, 2018, 140: 6156), and 3a was purchased from Anage Technology Company.

[0070] The synthesis steps of the thiourea-selenourea random copolymer are as follows: selenium disulfide 1 (52.5 mg, 0.37 mmol), isonitrile 2 (78.2 mg, 0.50 mmol), and diamine 3a (99.1 mg, 0.50 mmol) are placed in a polymerization tube equipped with a magnetic device, and the mixture is ventilated three times, with nitrogen as a protective gas, 2 mL of anhydrous DMSO is added, the temperature is raised to 80° C., and the reaction is stopped after stirring at 400 rpm for 12 hours, 5 mL of DMSO is added for dilution, the reaction solution is filtered through a dropper plugged with cotton, and then added dropwise to 120 mL of methanol and stirred vigorously, a large amount of white precipitate is precipitated, and the precipitate is filtered after standing, and the precipitate is washed with methanol (3×50 mL) and dried to obtain a white solid with a molecular weight of M w =236300 g / mol, M w / M n =2.95, yield 97%.

[0071] Take P1 as an example to explain the structure in detail:

[0072] Figure 2 is the X-ray photoelectron spectrum of polymer P1, where A is the S2p and Se 3p orbital electron X-ray photoelectron spectrum of polymer P1, and B is the S2p and Se 3d orbital electron X-ray photoelectron spectrum of polymer P1. Figure 1 It can be seen that the S2p orbital electron binding energy is 162.10 / 163.33, and the Se 3p orbital electron binding energy is 161.17 / 166.57. Through partial sealing fitting, it can be seen that the molar ratio of S to Se is 2:1.

[0073] The NMR spectrum of the thiourea-selenourea random copolymer prepared in this example is shown in Figure 1 , the NMR data are:

[0074] 1 H NMR(600MHz,d6-DMSO)δ9.93(s,1H),9.52(s,1H),8.42(s,1H),8.07(s,1H),7 .31-7.27(m,5H),7.21-7.18(m,5H),4.85-4.55(m,4H),3.86(d,J=4.9Hz,2H).

[0075] 13C NMR(150MHz,d6-DMSO)δ180.72,179.23,138.59,137.65,137.49,137.30,137 .04,136.32,129.29,128.91,127.37,127.31,124.64,123.70,49.90,47.01. 77 Se NMR (114MHz, d6-DMSO) δ211.07.Elemental analysis (C, N, S, H): Calc.C 61.36%, N12.45%, S9.50%, H 5.00%, Found C 61.15%, N12.30%, S 8.51%, H 5.10%.

[0076] Example 2

[0077] A thiourea-selenourea random copolymer compound, whose structural formula is shown in P2, and whose reaction formula is shown in formula (2):

[0078]

[0079] The synthesis steps of the thiourea-selenourea random copolymer are as follows: selenium disulfide 1 (52 mg, 0.37 mmol), isonitrile 2 (78 mg, 0.50 mmol), and diamine 3b (181 mg, 0.50 mmol) are placed in a polymerization tube equipped with a magnetic device, ventilated three times, nitrogen is used as a protective gas, 2 mL of anhydrous DMSO is added, the temperature is raised to 80° C., and the reaction is stopped after stirring at 400 rpm for 8 hours, 5 mL of DMSO is added for dilution, the reaction solution is filtered through a dropper plugged with cotton, and then added dropwise to 120 mL of methanol and stirred vigorously, a large amount of white precipitate is precipitated, and after standing, the precipitate is filtered by suction, and the precipitate is washed with methanol (3×50 mL) and dried to obtain a white solid with a yield of 99% and a molecular weight of M. w =208100 g / mol, M w / M n =1.97.

[0080] The NMR spectrum of the thiourea-selenourea random copolymer prepared in this example is shown in Figure 3 and Figure 4 , the NMR data are:

[0081] 1 H NMR (600MHz, d6-DMSO) δ9.92(s,0.5H),9.52(s,1H),8.38(s,0.5H),8.07(s,1H),7.44-7.30(m,8H),7.01-6.98(m,4H),4.87-4.73(m,4H).

[0082] 13 C NMR (150MHz, DMSO) δ181.03 (C=S), 179.77 (C=Se), 154.52, 153.53, 153.17, 137.60, 134.70, 127.74, 127.30 ,127.25,126.85,126.80,125.64,125.64,120.85,120.70,118.89,118.62,116.63,114.86,49.85,46.97.

[0083] Example 3

[0084] A thiourea-selenourea random copolymer, whose structural formula is shown in P3 and whose reaction formula is shown in formula (3):

[0085]

[0086] The synthesis steps of the thiourea-selenourea random copolymer are as follows: selenium disulfide 1 (52 mg, 0.37 mmol), isonitrile 2 (78 mg, 0.50 mmol), and diamine 3c (100 mg, 0.50 mmol) are placed in a polymerization tube equipped with a magnetic device, ventilated three times, nitrogen is used as a protective gas, 2 mL of anhydrous DMSO is added, the temperature is raised to 80° C., the reaction is stirred at 400 rpm for 8 hours, and then 5 mL of DMSO is added for dilution. The reaction solution is filtered through a dropper plugged with cotton and then added dropwise to 120 mL of methanol and stirred vigorously. A large amount of white precipitate is precipitated. After standing, the precipitate is filtered by suction, and the precipitate is washed with methanol (3×50 mL) and dried to obtain a white solid with a yield of 99% and a molecular weight of M. w =208100 g / mol, M w / M n =1.97.

[0087] The NMR image of the thiourea-selenourea random copolymer prepared in this example is shown in Figures 5-6 , the NMR data are:

[0088] 1 H NMR (600MHz, d6-DMSO) δ9.92(s,0.5H),9.52(s,1H),8.38(s,0.5H),8.07(s,1H),7.44-7.30(m,8H),7.01-6.98(m,4H),4.87-4.73(m,4H).

[0089] 13C NMR (150MHz, DMSO) δ181.03 (C=S), 179.77 (C=Se), 154.52, 153.53, 153.17, 137.60, 134.70, 127.74, 127.30 ,127.25,126.85,126.80,125.64,125.64,120.85,120.70,118.89,118.62,116.63,114.86,49.85,46.97.

[0090] Application Examples

[0091] The polymer P1 prepared in Example 1 was dissolved in N,N-dimethylacetamide solvent to prepare a solution with a mass fraction of 40%. 60 μL was evenly spread on a 2×2 cm single-polished silicon wafer and a P1 film was prepared by a spin coater at a speed of 1200 r / min and a spin coating time of 30 s. The refractive index was tested by an ellipsometer. The results are shown in FIG. Figure 7 .

[0092] Figure 7 The results show that the refractive index of the prepared copolymer film at 633nm is 1.7505, which is much higher than the commercial bisphenol A polycarbonate (PC) material (bisphenol A polycarbonate has a refractive index of 1.586 at 589nm), and has application potential in high refractive index materials and is expected to be used in the field of optical devices. Therefore, copolymer P1 has a high refractive index, which is due to the simultaneous presence of sulfur atoms and selenium atoms in the thiourea-selenourea random copolymer, which makes the polymer show a high refractive index in the film state.

[0093] It can be seen from the above embodiments that the present invention uses thioselenide, isonitrile and diamine to carry out multi-component polymerization reaction in a strong polar solvent to synthesize thiourea-selenourea random copolymer; the method has easy-to-obtain reaction raw materials, avoiding the use of hazardous reagents and scarce reagents; the reaction conditions are mild, easy to operate, and the yield is high; it has application potential in high refractive index materials and is expected to be used in the field of optical devices.

[0094] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a thiourea-selenourea random copolymer, characterized in that: The following steps are involved: The thiourea-selenourea random copolymer is obtained by mixing the thiourea-selenourea compound, the isonitrile compound, the diamine and the organic solvent and performing a polymerization reaction in a protective atmosphere; The sulfoselenide is selenium disulfide or selenium sulfide.

2. The preparation method according to claim 1, characterized in that: The isonitrile compound has a structure shown in Formula 1: In formula 1, R 1 It is an aromatic or aliphatic group.

3. The preparation method according to claim 2, characterized in that: The R 1 for 4. The preparation method according to claim 1, characterized in that: The diamine has a structure shown in Formula 2 or Formula 3: The R 2 include:

5. The preparation method according to claim 1, characterized in that: When the sulfoselenide is selenium disulfide, the molar ratio of the selenium disulfide, isonitrile compound and diamine is 2.0-2.3:3.0:3.0; when the sulfoselenide is selenium sulfide, the molar ratio of the selenium sulfide, isonitrile compound and diamine is 1.0-1.2:1:

1.

6. The preparation method according to claim 1, characterized in that: The protective atmosphere includes nitrogen and / or argon; the organic solvent includes one or more of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, dichloromethane and chloroform.

7. The preparation method according to claim 1 or 6, characterized in that: The concentration of the isonitrile compound in the organic solvent is 0.25-1 mol / L.

8. The preparation method according to claim 1, characterized in that: The polymerization reaction temperature is 25-100° C. and the reaction time is 1-12 hours.

9. The thiourea-selenourea random copolymer prepared by the preparation method according to any one of claims 1 to 8, characterized in that: It has the structure shown in Formula I or Formula II: In formula I, m:n=1~2.2:1; in formula II, x:y=1~2.2:

1.

10. Use of the thiourea-selenourea random copolymer according to claim 9 in the field of light-shielding materials.

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