A method for synthesizing polysulfides

Abstract

This invention discloses a method for synthesizing polysulfides, relating to the field of polymer chemistry. The synthesis method involves a solvent system and an inert gas atmosphere, under the action of a catalyst, where diol compound I and dithiol compound II or mercaptool compound V undergo dehydrogenation polymerization to generate polysulfide III or polysulfide VI. This synthesis method uses inexpensive and readily available reactants, employs mild reaction conditions, and the byproduct hydrogen can be used as a clean energy source. Furthermore, the reaction requires minimal equipment, conforming to the principles of green, efficient, and safe production, and possesses high commercial application value.

Description

Technical Field

[0001] This invention relates to the field of polymer chemistry, specifically to a method for synthesizing polysulfides. Background Technology

[0002] Polyester, as one of the most commonly used plastics, is widely used in packaging, agriculture, and medical fields. However, plastics have a relatively short lifespan, and the accumulation of large quantities of plastic after use can cause serious environmental pollution. Therefore, based on practicality and environmental friendliness, it is of great significance to synthesize recyclable polymers with good properties to replace polyester.

[0003] Polysulfides, as common heteroatom polymers, have attracted widespread attention in recent years. Introducing sulfur atoms into compounds can endow polymers with unique properties, including optical properties, chemical resistance, self-healing capabilities, and heavy metal trapping abilities, whether in the synthesis of new active pharmaceutical ingredients or in the synthesis of novel polymers with enhanced mechanical, electrical, and physicochemical properties. Meanwhile, polysulfides, as a novel material, have high research value. However, sulfur atoms readily deactivate common catalysts, making the synthesis of polysulfides a current challenge.

[0004] Traditional methods for synthesizing polysulfides primarily involve the reaction of thiols and acylation reagents under strong acid or strong base conditions. However, this approach generates unnecessary byproducts, and such polycondensation reactions require harsh conditions such as high temperature and vacuum, resulting in high energy consumption and low molecular weight polymers with uncontrollable molecular weight distribution, failing to meet the requirements of current green chemistry principles. In addition, ring-opening polymerization has been extensively studied as a method for synthesizing polysulfides. It improves atom utilization through ring-opening of thiolactones, allowing for controlled polymerization to obtain polysulfides. Professor Lü Hua synthesized thiolactones from 4-hydroxyproline to complete ring-opening polymerization; Hong Miao's team prepared five-membered ring thiolactones (TnBL) using succinic acid and synthesized PTBL through ring-opening; Tao Youhua's research group prepared thiolactide and further ring-opened it to prepare polysulfides. However, ring-opening polymerization requires complex cyclic thiolactone monomers, whose synthesis steps are cumbersome and difficult to commercialize. Meanwhile, due to the simple structure of cyclic thiolactone monomers, the synthesized polysulfides have a simple structure and cannot meet the requirements of the current complex environmental conditions. Therefore, it is urgent to develop a green, efficient and widely applicable polymerization method to achieve large-scale industrial production of polysulfides. Summary of the Invention

[0005] This invention aims to provide a method for synthesizing polysulfides. This method utilizes diol compound I and dithiol compound II or mercaptool compound V through dehydrogenation polymerization to generate polysulfide III or polysulfide VI. The reactants used in this method are inexpensive and readily available, and the required catalyst is reduced compared to traditional methods, effectively lowering synthesis costs. Furthermore, no other additives are needed, and the only byproduct, hydrogen, can be used as a clean energy source. Compared to traditional polymerization methods, this method is more efficient and environmentally friendly, facilitating large-scale industrial production.

[0006] This invention provides a method for synthesizing polysulfide, wherein in a solvent system and an inert gas atmosphere, under the action of a catalyst, diol compound I and dithiol compound II undergo dehydrogenation polymerization to generate polysulfide III;

[0007]

[0008] Among them, R 1 R 2 The groups are independently C2-C 30 Aliphatic alkyl groups, C3-C 30 Cycloalkyl and heterocycloalkyl with C5-C 30 The polysulfide is any one of aromatic and heteroaromatic groups; n is any integer from 1 to 300; the molecular weight of the polysulfide is 0.5 million to 500,000.

[0009] The synthesis method provided by this invention allows the entire reaction system to be completely recycled, and the only reaction byproduct is hydrogen gas. It also eliminates the need for harmful acylation reagents, enabling efficient and green synthesis of thioesters under relatively mild conditions.

[0010] Optionally, the solvent system includes at least one of cyclohexane, benzene, toluene, bromobenzene, chlorobenzene, p-xylene, m-xylene, o-xylene, anisole, mesitylene, tetrahydrofuran, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, dimethylformamide, dimethyl sulfoxide, and hexamethyldisiloxane.

[0011] Optionally, the inert gas atmosphere includes at least one of argon and nitrogen.

[0012] Optionally, the catalyst is an acridine-based ruthenium catalyst, the structure of which is shown in Formula IV:

[0013]

[0014] Optionally, the diol compound I includes any one of 1,2-ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,16-hexadecanediol, terephthalic acid, isophthalic acid, and 2,5-furandiol.

[0015] Optionally, the dithiol compound II includes any one of 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,11-undecanedithiol, 1,12-dodecanedithiol, 1,13-tridecanedithiol, 1,14-tetradecanedithiol, 1,15-pentadecanedithiol, 1,16-hexadecanedithiol, p-phenylenediol, and m-phenylenediol.

[0016] Optionally, the molar ratio of the diol compound I to the dithiol compound II is 1:1.

[0017] Optionally, the molar ratio of the catalyst to the diol compound I is 1:(20-1000).

[0018] Optionally, the concentrations of the diol compound I and the dithiol compound II are 0.01 mol / L to 0.50 mol / L.

[0019] Optionally, the dehydrogenation polymerization of the diol compound I and the dithiol compound II includes: reacting the diol compound I and the dithiol compound II at 80℃-240℃ for 1h-80h to generate polysulfide ester III.

[0020] Optionally, mercaptool compound V can be used instead of diol compound I and dithiol compound II for dehydrogenation polymerization to generate polysulfide VI;

[0021]

[0022] Among them, R 3 The group is C1-C 30 Aliphatic alkyl groups, C3-C 30 Cycloalkyl and heterocycloalkyl with C5-C 30 It can be any one of aromatic and heteroaromatic groups; n is any integer from 1 to 300. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments are briefly introduced below.

[0024] Figure 1 The reaction formula provided by this invention is for the dehydrogenation polymerization of diol compound I and dithiol compound II to synthesize polysulfide ester III;

[0025] Figure 2 The reaction formula for the dehydrogenation polymerization of mercaptool compound V to synthesize polysulfide VI is provided by the present invention;

[0026] Figure 3 The image shows the 1H NMR spectrum of the polysulfide synthesized in Example 1 of this invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0028] As described in the summary of the invention, the embodiments of the present invention include any other embodiments described herein, which may be combined in any way, and the description of variables in the embodiments applies not only to the method of the present invention but also to the polysulfide prepared therefrom. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed, and reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0029] This invention provides a method for synthesizing polysulfide, wherein in a solvent system and an inert gas atmosphere, under the action of a catalyst, diol compound I and dithiol compound II undergo dehydrogenation polymerization to generate polysulfide III;

[0030]

[0031] Among them, R 1 R 2 The groups are independently C2-C 30 Aliphatic alkyl groups, C3-C 30 Cycloalkyl and heterocycloalkyl with C5-C 30 The polysulfide is any one of aromatic and heteroaromatic groups; n is any integer from 1 to 300, and the molecular weight of the polysulfide is 0.5 million to 500,000.

[0032] In some embodiments, the solvent system includes at least one of cyclohexane, benzene, toluene, bromobenzene, chlorobenzene, p-xylene, m-xylene, o-xylene, anisole, mesitylene, tetrahydrofuran, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, dimethylformamide, dimethyl sulfoxide, and hexamethyldisiloxane.

[0033] In some embodiments, the inert gas atmosphere includes at least one of argon and nitrogen.

[0034] In some embodiments, the catalyst is an acridine-based ruthenium catalyst, the structure of which is shown in Formula IV:

[0035]

[0036] In some embodiments, the diol compound I includes any one of 1,2-ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,16-hexadecanediol, terephthalic acid, isophthalic acid, and 2,5-furandiol.

[0037] In some embodiments, the dithiol compound II includes any one of 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,11-undecanedithiol, 1,12-dodecanedithiol, 1,13-tridecanedithiol, 1,14-tetradecanedithiol, 1,15-pentadecanedithiol, 1,16-hexadecanedithiol, p-phenylenediol, and m-phenylenediol.

[0038] In some embodiments, the molar ratio of the diol compound I to the dithiol compound II is 1:1.

[0039] In some embodiments, the molar ratio of the catalyst to the diol compound I is 1:(20-1000).

[0040] In some embodiments, the concentrations of diol compound I and dithiol compound II are 0.01 mol / L to 0.50 mol / L.

[0041] In some embodiments, the synthesis method includes the following steps:

[0042] S1. In the solvent system, the catalyst, diol compound I, and dithiol compound II are mixed.

[0043] S2, under an inert gas atmosphere, react at 80℃-240℃ for 1h-80h, and then separate and purify to obtain polysulfide III.

[0044] In some embodiments, mercapto alcohol compound V can be used instead of diol compound I and dithiol compound II for dehydrogenation polymerization to generate polysulfide VI;

[0045]

[0046] Among them, R 3 The group is C1-C 30 Aliphatic alkyl groups, C3-C 30 Cycloalkyl and heterocycloalkyl with C5-C 30 It can be any one of aromatic and heteroaromatic groups; n is any integer from 1 to 300.

[0047] In practice, the product needs to be repeatedly dissolved and precipitated with an organic solvent at least three times. Specifically, the organic solvent used for dissolution includes at least one of tetrahydrofuran, dichloromethane, and chloroform, and the organic solvent used for precipitation includes at least one of methanol, ethanol, and petroleum ether.

[0048] Example 1

[0049] Example 1 of this invention provides a method for synthesizing polysulfides, comprising the following steps:

[0050] S1. Inside the glove box, add 1 mL of toluene and 1 mL of water to a 100 mL Schlenk flask to dissolve 5.7 mg (0.01 mmol) of acridine-based ruthenium catalyst (CAS: 1254107-28-2), then add 1 mmol of 1,6-hexanedithiol (CAS: 1191-43-1) and 1 mmol of 1,6-hexanediol (CAS: 629-11-8), seal the Schlenk flask and remove it from the glove box;

[0051] S2. Under a nitrogen atmosphere, the container was heated to 150°C in an oil bath and reacted for 5 hours. Then, the reaction was carried out under vacuum for 2 days. After the Schlenk flask was cooled to room temperature, the product was taken out, dissolved in tetrahydrofuran, and then precipitated in methanol. The dissolution-precipitation process was repeated three times. The solid product was collected and dried under vacuum to obtain polysulfide.

[0052] Polysulfide was characterized by nuclear magnetic resonance (NMR), GPC, and DSC. Its proton NMR spectrum is shown below. Figure 3 As shown, the calculated yield is 78.3%.

[0053] Table 1. Synthesis results in Example 1

[0054]

[0055] Examples 2 to 11

[0056] Examples 2 to 11 of the present invention provide a method for synthesizing polysulfides. The difference from Example 1 is that the solvent and reaction temperature used in step S1 are as shown in Table 2.

[0057] Table 2. Solvents, reaction temperatures, and yields in Examples 2 to 11

[0058] serial number solvent Temperature / ℃ Yield / % Example 2 Toluene 120 14.2 Example 3 Dioxane 150 50.3 Example 4 Toluene:water = 1:1 150 78.3 Example 5 hexamethyldisiloxane 150 22.6 Example 6 Anisole 150 16.1 Example 7 Tetrahydrofuran 150 70.4 Example 8 1,2-Dimethoxyethane:water = 1:1 120 54.3 Example 9 1,2-Dimethoxyethane 100 69.7 Example 10 Toluene:hexamethyldisiloxane = 1:1 80 17.4 Example 11 dichloromethane 150 56.8

[0059] Examples 12 to 17

[0060] Examples 12 to 17 of this invention provide a method for synthesizing polysulfides. The difference from Example 1 is that the content of the catalyst added in step S1 and the reaction time are as shown in Table 3.

[0061] Table 3 Catalyst content, reaction time, and yield of Examples 12 to 17

[0062] serial number Catalyst content Reaction time / h Yield / % Example 12 0.005mmol 12 23.5 Example 13 0.01mmol 24 74.3 Example 14 0.015mmol 24 76.9 Example 15 0.02mmol 36 77.3 Example 16 0.025mmol 24 78.8 Example 17 0.03mmol 36 79.4

[0063] Examples 18 to 27

[0064] Examples 18 to 27 of this invention provide a method for synthesizing polysulfides. The difference from Example 1 is that the types of diols and dithiols added in step S1 are as shown in Table 4.

[0065] Table 4. Diol and dithiol compounds and synthesis results from Examples 18 to 27.

[0066]

[0067]

[0068] Examples 28 to 33

[0069] Examples 28 to 33 of this invention provide a method for synthesizing polysulfides. The difference from Example 1 is that in step S1, mercaptools are used instead of diols and dithiols as reaction substrates, as shown in Table 5.

[0070] Table 5. Thiol alcohol compounds and synthesis results in Examples 28 to 33.

[0071]

[0072] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A method for synthesizing polysulfides, characterized in that, In a solvent system and in an inert gas atmosphere, at 80 ℃-240 ℃ and under the action of a catalyst, diol compound I and dithiol compound II undergo dehydrogenation polymerization to generate polysulfide ester III; ； Among them, R 1 R 2 The groups are independently C2-C 30 Aliphatic alkyl groups, C3-C 30 Cycloalkyl and heterocycloalkyl with C5-C 30 The aromatic group and heteroaromatic group are any one of them; n is any integer from 1 to 300; the molecular weight of the polysulfide is 0.5 million to 500,000; The catalyst is an acridine-based ruthenium catalyst, and its structure is shown in Formula IV: 。 2. The synthesis method according to claim 1, characterized in that, The solvent system includes at least one of cyclohexane, benzene, toluene, bromobenzene, chlorobenzene, p-xylene, m-xylene, o-xylene, anisole, mesitylene, tetrahydrofuran, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, dimethylformamide, dimethyl sulfoxide, and hexamethyldisiloxane.

3. The synthesis method according to claim 1, characterized in that, The inert gas atmosphere includes at least one of argon and nitrogen.

4. The synthesis method according to claim 1, characterized in that, The diol compound I includes any one of 1,2-ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,16-hexadecanediol, terephthalic acid, isophthalic acid, and 2,5-furandiol.

5. The synthesis method according to claim 1, characterized in that, The dithiol compound II includes any one of 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,11-undecanedithiol, 1,12-dodecanedithiol, 1,13-tridecanedithiol, 1,14-tetradecanedithiol, 1,15-pentadecanedithiol, 1,16-hexadecanedithiol, p-phenylenediol, and m-phenylenediol.

6. The synthesis method according to claim 1, characterized in that, The molar ratio of the diol compound I to the dithiol compound II is 1:1; the molar ratio of the catalyst to the diol compound I is 1:(20-1000).

7. The synthesis method according to claim 1, characterized in that, The concentrations of the diol compound I and the dithiol compound II are 0.01 mol / L to 0.50 mol / L.

8. The synthesis method according to claim 1, characterized in that, The dehydrogenation polymerization of diol compound I and dithiol compound II includes reacting at 80 ℃-240 ℃ for 1 h-80 h.

9. The synthesis method according to claim 1, characterized in that, Mercaptool compound V can be used to replace diol compound I and dithiol compound II for dehydrogenation polymerization to generate polysulfide VI; ； Among them, R 3 The group is C1-C 30 Aliphatic alkyl groups, C3-C 30 Cycloalkyl and heterocycloalkyl with C5-C 30 It can be any one of aromatic and heteroaromatic groups; n is any integer from 1 to 300.

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