Sulfur-containing polymer and preparation method thereof

Abstract

The present invention belongs to the field of polymer synthesis, and in particular to a sulfur-containing polymer and a preparation method thereof. Under the conditions of 0-80°C, a binary copolymerization system is formed with elemental sulfur S8 and a vinyl monomer, or a ternary copolymerization system is formed with elemental sulfur S8 and a vinyl monomer and an epoxy monomer, and the copolymerization reaction is carried out for 6-24 hours under a thiol and / or base initiation system, and a sulfur-containing polymer is obtained by a one-step method. The monomer use range of this method is wide, the reaction conditions are mild, and it can react under solvent or solvent-free conditions, overcoming the defect that traditional inverse vulcanization requires high-temperature reaction, and effectively reducing energy consumption. The synthesized polymer has great application prospects in the fields of electrochemistry, high-refractive index resins, adhesives, energy storage materials, etc. The monomer raw materials involved in the present invention are cheap and easy to obtain, and the preparation method is simple. It is a very valuable novel method for preparing sulfur-containing polymers under mild conditions.

Description

Technical Field

[0001] The invention belongs to the field of polymer synthesis, and particularly relates to a sulfur-containing polymer and a preparation method thereof. Background Art

[0002] As one of the top three most abundant elements in the Earth's crust, sulfur possesses numerous exceptional properties, including UV absorption, high molar refractive index, high theoretical electrode capacity, and sensitive metal detection. Sulfur, a byproduct of hydrodesulfurization during the petrochemical industry, is produced in tens of millions of tons annually. However, its applications are very limited, creating a significant opportunity for the synthesis of novel functional polymers from elemental sulfur. However, while sulfur possesses these exceptional properties, its poor solubility also presents challenges for its synthesis.

[0003] A large number of reports have been published on the blending of elemental sulfur with carbon-based monomers to form inorganic nanomaterials for lithium-sulfur batteries or building materials. Unfortunately, polymerization methods that directly use elemental sulfur as a sulfur source to synthesize functional materials are still very limited. In addition to overcoming the poor physical properties of elemental sulfur and its reaction inertness at low temperatures, the low stability of the synthesized high-sulfur polymers also needs to be addressed. In 2013, Pyun et al. first reported the free radical copolymerization of molten sulfur with DIB bulk to synthesize high-sulfur polymers. This polymerization method, which uses a large amount of sulfur as a comonomer and a small amount of vinyl polymer as a cross-linking agent, is called inverse vulcanization. Subsequently, a large number of multifunctional comonomers were used as cross-linking agents for inverse vulcanization to participate in the polymerization reaction.

[0004] Inverse vulcanization holds promise for industrial-scale application due to its simple synthesis, low-cost raw materials, scalability, and high atom efficiency. However, challenges hindering large-scale production remain. During free radical polymerization, sulfur radicals absorb hydrogen, releasing the hazardous gas H2S or forming terminal thiols, leading to the selective addition of CQC monomers. High temperatures also exhibit Trommsdorff–Norrish autoacceleration (high temperature and high viscosity prevent termination). Furthermore, the stringent reaction temperatures require the selection of olefin monomers with suitable boiling points to prevent their volatilization prior to polymerization. Furthermore, recent studies have shown that monomers, including acrylates, are inert due to the electron-withdrawing conjugation effect.

[0005] In order to reduce energy consumption and circumvent the above problems, it is urgent to select suitable metal or small molecule catalysts to form an ionic polymerization system, avoid the problems caused by free radical polymerization, and complete the reaction at room temperature. Summary of the Invention

[0006] The present invention discloses a method for synthesizing a high-sulfur polymer under mild conditions. Specifically, at 0-80°C, a binary copolymerization system of elemental sulfur (S8) and a vinyl monomer, or a ternary copolymerization system of elemental sulfur (S8) with a vinyl monomer and an epoxy monomer, is carried out under a thiol and / or base initiation system for 6-24 hours to obtain a sulfur-containing polymer in one step.

[0007] The method for preparing sulfur-rich polymers by one-step method using elemental sulfur, dienes and epoxy monomers is to mix elemental sulfur S8 with olefin monomers, add organic base catalysts and / or thiol catalysts, use inert gas as protective gas, and react at room temperature for 6-24 hours to obtain a sulfur-containing polymer. The mass ratio of elemental sulfur S8 to crosslinker varies from 5:95 to 95:5.

[0008] The method for preparing a sulfur-rich polymer by a one-step method using elemental sulfur, dienes and epoxy monomers is as follows: elemental sulfur S8 is mixed with olefins and epoxy monomers, and then an organic base catalyst and / or a thiol catalyst is added. An inert gas is used as a protective gas, and the reaction is carried out at room temperature for 6-24 hours to obtain a sulfur-containing polymer. The mass ratio of elemental sulfur S8 to olefins and epoxy varies from 10:50:20 to 50:50:50.

[0009] The vinyl monomers used in the binary or ternary copolymerization system of the present invention can be monoolefins including methyl acrylate (MA), n-butyl acrylate (BA), phenyl acrylate (PA), benzyl acrylate (BNA), acrylamide (AM), and N,N-dimethylacrylamide (DMAA); they can also be dienes or polyolefins including 1,2-hexanediol diacrylate (EGDA), 1,4-butanediol diacrylate (BDDA), and polyethylene glycol diacrylate (PEGDA); or they can be mixtures of vinyl monomers with different functionalities.

[0010] The epoxy monomers in the ternary copolymer system of the present invention include, but are not limited to, bisphenol A diglycidyl ether (EP), epoxidized soybean oil (ESO), and polyethylene glycol diglycidyl ether (PEGDGE).

[0011] The thiol described in the present invention is benzyl mercaptan (BnSH);

[0012] The organic base catalyst of the present invention is one or more of 1,4-diazabicyclo〔2.2.2〕octane (DABCO), 4-dimethylaminopyridine (DMAP), 1,8-diazabicycloundec-7-ene (DBU), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and triethylamine (TEA).

[0013] The advantages of the present invention compared to the prior art are as follows:

[0014] (1) The present invention overcomes the high temperature conditions required for traditional inverse vulcanization, reduces energy consumption, and avoids the release of toxic gas hydrogen sulfide caused by the high temperature reaction process.

[0015] (2) The present invention can successfully polymerize under mild conditions, and the crosslinking monomer uses an acrylic ester monomer that is inert in the traditional reverse vulcanization reaction, which greatly expands a large number of low-boiling point crosslinking agents such as monoolefins (methyl acrylate, etc.) that cannot be used due to high reaction temperatures.

[0016] (3) The present invention has a high reaction degree, and low-temperature ionic polymerization avoids the low reaction degree caused by the auto-acceleration phenomenon caused by the free radical polymerization process.

[0017] (4) The polymerization product of the present invention under mild conditions has a higher degree of reaction than free radical polymerization, and there is no chain extension reaction of elemental sulfur, which reduces the proportion of long sulfur chains. The prepared polymer has the advantages of high thermal stability and large molecular weight, and the weight-average molecular weight can be as high as 220,000 g / mol.

[0018] (5) The present invention adopts a solvent-free method to prepare sulfur-containing polymers, which is in line with the green concept; the use of a solvent method to prepare high-sulfur-containing polymers can to a certain extent solve the problem of loss of molding applications due to poor solubility caused by high sulfur content.

[0019] (6) The two raw materials, elemental sulfur S8 and the cross-linking agent, in the present invention are both industrial waste or natural products, which are cheap and abundant, environmentally friendly and harmless, and inexpensive.

[0020] (7) The cross-linked polymer product prepared in the present invention is a thermosetting product, but it has a large number of SS dynamic bonds and can be reprocessed and molded by inducing SS dynamic exchange.

[0021] (8) The preparation method of the present invention is simple, a one-pot method at room temperature, and has high yield and high atom utilization. The high-sulfur content polymer prepared is a degradable polymer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The raw materials MA and polymer P(S) used in Example 1 of the present invention are 50 -co-MA 50 ) infrared image.

[0023] Figure 2 The MA in Example 1 of the present invention and the high sulfur content polymer P (S 50 -co-MA 50 )of 1 H-NMR comparison chart.

[0024] Figure 3 The raw materials DMA and high sulfur content polymer P(S) used in Example 7 of the present invention are 50-co-DMAA 50 ) infrared image.

[0025] Figure 4 The DMA in Example 7 of the present invention and the high sulfur content polymer P(S 50 -co-DMAA 50 )of 1 H-NMR comparison chart.

[0026] Figure 5 The BDDA in Example 8 of the present invention and the high sulfur content polymer P (BDDA-co-S 56％ ) FT-TR comparison chart.

[0027] Figure 6 The elemental sulfur S8 in Example 8 of the present invention and the high sulfur content polymer P (BDDA-co-S 56％ ) DSC comparison chart.

[0028] Figure 7 The BDDA in Example 9 of the present invention and the high sulfur content polymer P (BDDA-co-S 95％ ) FT-TR comparison chart.

[0029] Figure 8 The elemental sulfur S8 in Example 9 of the present invention and the high sulfur content polymer P(BDDA-co-S 95％ ) DSC comparison chart.

[0030] Figure 9 The BDDA in Example 10 of the present invention and the high sulfur content polymer P (BDDA-co-S 56％ )-TBD FT-TR comparison chart.

[0031] Figure 10 The elemental sulfur S8 in Example 10 of the present invention and the high sulfur content polymer P(BDDA-co-S 56％ )-TBD DSC comparison chart.

[0032] Figure 11 The BDDA in Example 12 of the present invention and the high sulfur content polymer P (BDDA-co-S 56％ )-TEA FT-TR comparison chart.

[0033] Figure 12 The elemental sulfur S8 in Example 12 of the present invention and the high sulfur content polymer P(BDDA-co-S 56％ )-TEA DSC comparison chart.

[0034] Figure 13The elemental sulfur S8 in Example 14 of the present invention and the high sulfur content polymer P(PEGDA-co-S 56％ )’s XRD comparison diagram.

[0035] Figure 14 The elemental sulfur S8 in Example 14 of the present invention and the high sulfur content polymer P(PEGDA-co-S 56％ ) DSC comparison chart.

[0036] Figure 15 The DER in Example 16 of the present invention and the high sulfur content polymer P (BDDA-DER-S 30％ ) FT-TR comparison chart.

[0037] Figure 16 The elemental sulfur S8 in Example 16 of the present invention and the high sulfur content polymer P (BDDA-DER-S 30％ ) DSC comparison chart.

[0038] Figure 17 The high sulfur content polymer P(BDDA-DER-S in Example 16 of the present invention 30％ )’s TGA curve.

[0039] Figure 18 The high sulfur content polymer P(BDDA-DER-S in Example 16 of the present invention 30％ ) GPC sampling differential distribution curve. DETAILED DESCRIPTION

[0040] The following is a further description of a method for synthesizing a high-sulfur-content polymer by base catalysis at room temperature using elemental sulfur as a sulfur source, using specific examples.

[0041] Example 1

[0042] Weigh 0.256g of elemental sulfur S8 powder, 0.086g of methyl acrylate (MA) and 10uL of DBU into a 5mL flask, mix and stir at room temperature under inert gas protection for 6h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0043] Example 2

[0044] Weigh 0.256g of elemental sulfur S8 powder, 0.086g of methyl acrylate (MA) and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0045] Example 3

[0046] Weigh 0.256g of elemental sulfur S8 powder, 0.086g of butyl acrylate (BA) and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0047] Example 4

[0048] Weigh 0.256g of elemental sulfur S8 powder, 0.148g of phenyl acrylate (PA) and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0049] Example 5

[0050] Weigh 0.256g of elemental sulfur S8 powder, 0.152g of benzyl acrylate (BNA) and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant and dried in a vacuum oven to obtain a yield of 99%.

[0051] Example 6

[0052] Weigh 0.256g of elemental sulfur S8 powder, 0.071g of acrylamide (AM) and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 91%.

[0053] Example 7

[0054] Weigh 0.256g of elemental sulfur S8 powder, 0.0990g of N,N-dimethylacrylamide (DMAA) and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant and dried in a vacuum oven to obtain a yield of 90%.

[0055] Example 8

[0056] Weigh 0.256g of elemental sulfur S8 powder, 0.198g of 1,4-butanediol diacrylate (BDDA), and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0057] Example 9

[0058] Weigh 0.243g of elemental sulfur S8 powder, 0.02g of 1,4-butanediol diacrylate (BDDA), and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0059] Example 10

[0060] Weigh 0.256 g of elemental sulfur S8 powder, 0.198 g of 1,4-butanediol diacrylate (BDDA), and 1.2 mg of TBD in a 5 mL flask. Under inert gas protection, mix and stir at room temperature for 24 h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and then dried in a vacuum oven to obtain a yield of 99%.

[0061] Example 11

[0062] Weigh 0.256 g of elemental sulfur S8 powder, 0.198 g of 1,4-butanediol diacrylate (BDDA), and 1.8 mg of DABCO into a 5 mL flask. Under inert gas protection, mix and stir at room temperature for 24 h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and then dried in a vacuum oven to obtain a yield of 99%.

[0063] Example 12

[0064] Weigh 0.256g of elemental sulfur S8 powder, 0.198g of 1,4-butanediol diacrylate (BDDA), and 8uL of TEA into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0065] Example 13

[0066] Weigh 0.256g of elemental sulfur S8 powder, 0.17g of 1,2-ethylene glycol diacrylate (EGDA), and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 99%.

[0067] Example 14

[0068] Weigh 0.256g of elemental sulfur S8 powder, 0.575g of polyethylene glycol diacrylate (PEGDA), and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and dried in a vacuum oven to obtain a yield of 89%.

[0069] Example 15

[0070] Weigh 0.256g of elemental sulfur S8 powder, 0.198g of 1,4-butanediol diacrylate (BDDA), 0.226g of bisphenol A diepoxide and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and then dried in a vacuum oven to obtain a yield of 98%.

[0071] Example 16

[0072] Weigh 0.256g of elemental sulfur S8 powder, 0.198g of 1,4-butanediol diacrylate (BDDA), 0.058g of bisphenol A diepoxide and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and then dried in a vacuum oven to obtain a yield of 98%.

[0073] Example 17

[0074] Weigh 0.256g of elemental sulfur S8 powder, 0.198g of 1,4-butanediol diacrylate (BDDA), 0.662g of epoxy soybean oil and 10uL of DBU into a 5mL flask. Under inert gas protection, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and then dried in a vacuum oven to obtain a yield of 98%.

[0075] Example 18

[0076] Weigh 0.256g of elemental sulfur S8 powder, 0.198g of 1,4-butanediol diacrylate (BDDA), 0.586g of polyethylene glycol diglycidyl ether and 10uL of DBU into a 5mL flask. Under the protection of inert gas, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and then dried in a vacuum oven to obtain a yield of 98%.

[0077] Example 19

[0078] Weigh 0.256g of elemental sulfur S8 powder, 0.198g of 1,4-butanediol diacrylate (BDDA), 0.586g of polyethylene glycol diglycidyl ether, 10uL of DBU, and 12.4uL of BnSH into a 5mL flask. Under the protection of inert gas, mix and stir at room temperature for 24h. After the reaction, the mixture is repeatedly precipitated and washed with a precipitant, and then dried in a vacuum oven to obtain a yield of 98%.

Claims

1. A method for preparing a sulfur-containing polymer, characterized in that: The preparation method of the sulfur-containing polymer comprises: forming a binary copolymerization system of elemental sulfur S8 and a vinyl monomer or forming a ternary copolymerization system of elemental sulfur S8, a vinyl monomer and an epoxy monomer, and performing copolymerization reaction under a thiol and / or organic base initiation system to obtain the sulfur-containing polymer in a one-step process; The vinyl monomer is a monoene, a diene, a polyene or a mixture of vinyl monomers of different functionalities; Wherein, the monoolefin is methyl acrylate, n-butyl acrylate, phenyl acrylate, benzyl acrylate, acrylamide, N,N-dimethylacrylamide; the diene or polyene is 1,2-hexanediol diacrylate, 1,4-butanediol diacrylate, polyethylene glycol diacrylate; The copolymerization reaction temperature is 0-80°C, and the polymerization reaction time is 6-24h.

2. The method for preparing a sulfur-containing polymer according to claim 1, wherein The thiol is benzyl mercaptan, and the organic base is one or more of 1,4-diazabicyclo〔2.2.2〕octane, 4-dimethylaminopyridine, 1,8-diazabicycloundec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and triethylamine.

3. The method for preparing a sulfur-containing polymer according to claim 1, wherein The epoxy monomers are bisphenol A diglycidyl ether, epoxy soybean oil, and polyethylene glycol diglycidyl ether.

4. The method for preparing a sulfur-containing polymer according to claim 1, wherein The mass ratio of sulfur to vinyl monomer in the binary copolymerization system is 5:95-95:5; the mass ratio of sulfur, vinyl monomer and epoxy monomer in the ternary copolymerization system is 128:99:29-331.

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