Sulfur-containing polymer as well as preparation method and application thereof

Abstract

The invention discloses a sulfur-containing polymer and a preparation method and application thereof, and also provides a preparation method of the polymer, and the preparation method comprises the following specific steps: adding styrene, sulfur and an accelerant into a quartz test tube or a quartz groove, and carrying out light irradiation catalytic reaction at normal temperature to obtain a styrene and sulfur copolymer. According to the preparation method, reaction can be carried out at room temperature, no solvent is needed, the synthesis process is greatly simplified, energy consumption is reduced, toxic gas H2S is not generated, atom economy is high, environment friendliness is achieved, a new thought is provided for preparation of sulfur-containing polymers, and high application potential is achieved.

Description

Technical Field

[0001] This invention belongs to the field of materials technology and relates to the preparation of sulfur-containing polymers, specifically to a sulfur-containing polymer, its preparation method, and its application. Background Technology

[0002] Sulfur is a common chemical raw material, with high yield and low price. Sulfur-rich polymers refer to polymers with a high elemental sulfur content, and they have wide applications in lithium-sulfur batteries, heavy metal ion adsorption, curable plastics, self-healing materials, and catalyst supports. In recent years, the synthesis of sulfur-rich polymers from sulfur has attracted widespread attention. In 2013, Pyun et al. first successfully reacted sulfur with 1,3-diisopropenylbenzene (DIB) via thermal polymerization at 185 °C, obtaining sulfur-containing polymers. However, the drawbacks were the excessively high reaction temperature and the generation of toxic H2S gas. In 2019, Wu and Hasell et al. found that diethyldithiocarbamate metal accelerators could enable the reaction to occur successfully at 135 °C. The introduction of these accelerators improved the yield and expanded the substrate range of this polymerization reaction. However, the self-acceleration phenomenon in the reaction and the prevention of toxic H2S gas generation still could not be solved, and it could not be applied to volatile monomers. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a styrene-sulfur copolymer. This copolymer is prepared from styrene and sulfur. The present invention also provides a method for preparing this copolymer. This method can be carried out at room temperature without solvents, which greatly simplifies the synthesis process and reduces energy consumption. It does not produce toxic gas H2S, has high atom economy, is environmentally friendly, and provides a new approach for preparing sulfur-containing polymers, possessing strong application potential.

[0004] This invention is achieved through the following technical solution: A sulfur-containing polymer, obtained by copolymerizing styrene and sulfur, wherein the polymer comprises at least one or more of the following structural formulas:

[0005] In the formula, n = 1 to 4.

[0006] A further improvement to the present invention is as follows: A method for preparing a sulfur-containing polymer includes the following steps: adding styrene, sulfur, and an accelerator into a quartz test tube or quartz trough, and catalyzing the reaction under light irradiation at room temperature to obtain a styrene-sulfur copolymer.

[0007] Furthermore, the mass ratio of styrene to sulfur is 1:1.5 to 1.5:1.

[0008] Furthermore, the accelerator is one or a mixture of two or more of the following: zinc ethyl dithiocarbamate, zinc dibutyl dithiocarbamate, zinc dimethyl dithiocarbamate, 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxodiethylene-2-benzothiazole sulfenamide, N,N'-dicyclohexyl-2-benzothiazole sulfenamide, tetramethylthiuram disulfide, tetramethylthiuram monosulfide, tetraethylthiuram disulfide, pentamethylthiuram hexasulfide, or diphenylguanidine.

[0009] Furthermore, the amount of the accelerator is 1-5% of the total mass of styrene and sulfur.

[0010] Furthermore, the wavelength of the light source for the photocatalytic reaction is 250~400 nm, and the irradiation time is 24~48 h.

[0011] A further improvement to the present invention is as follows: Applications of the above-mentioned sulfur-containing polymers in rubber products.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The styrene-sulfur copolymer proposed in this invention has a narrow molecular weight distribution and a high sulfur content. When used in the preparation of rubber products, it can replace sulfur in the formulation to obtain better resistance to reversion to sulfurization. The elongation at break of the rubber compound is significantly improved, and the aging performance, low temperature performance and abrasion performance are also better than those of sulfur formulations.

[0013] The photocatalytic method for preparing styrene-sulfur copolymers provided by this invention does not require high-temperature reaction; it effectively reduces energy consumption and monomer volatilization; the preparation method of this invention has a wide variety of selectable promoters, no toxic gas H2S is generated during the reaction, the wavelength range of the light source is selectable, the reaction is simple, the raw materials are cheap and readily available, and the atom economy is high. Attached Figure Description

[0014] Figure 1 The product of Embodiment 3 of the present invention 1 H NMR spectrum; Figure 2 The FT-IR image of the product of Example 3 of this invention; Figure 3 The TG and DSC images of the product of Example 3 of this invention are shown below. Figure 4 This is a GPC diagram of the product of Example 3 of the present invention. Detailed Implementation

[0015] The present invention will now be described in detail with reference to specific embodiments.

[0016] Example 1 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of zinc diethyldithiocarbamate in a container at 25 cm. 2 No obvious reaction was observed when the quartz reaction tank was irradiated with white light for 24 hours.

[0017] Example 2 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of zinc diethyldithiocarbamate in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 254 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0018] Example 3 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of zinc diethyldithiocarbamate in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0019] Example 4 Place 500 mg of sulfur powder, 750 mg of styrene, and 40 mg of zinc diethyldithiocarbamate in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0020] Example 5 Place 750 mg of sulfur powder, 500 mg of styrene, and 40 mg of zinc diethyldithiocarbamate in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0021] Example 6 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of zinc dimethyl dithiocarbamate in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0022] Example 7 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of zinc dibutyldithiocarbamate in a container at 25 cm. 2In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0023] Example 8 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of 2-mercaptobenzothiazole in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0024] Example 9 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of N-cyclohexyl-2-benzothiazole sulfenamide in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0025] Example 10 Place 500 mg of sulfur powder, 500 mg of styrene, and 30 mg of tetramethylthiuram disulfide in a container at 25 cm. 2 In a quartz reaction tank, the mixture was irradiated with 365 nm ultraviolet light for 24 hours. The resulting dark brown solid substance, which is a copolymer of styrene and sulfur, was obtained by scraping it off with a scraper.

[0026] Example 11 100 mg of sulfur powder, 100 mg of styrene, and 6 mg of zinc diethyldithiocarbamate were placed in a quartz test tube, 2 ml of dichloromethane was added, and the mixture was irradiated with 365 nm ultraviolet light for 24 h. No obvious reaction was observed.

[0027] Example 12 100 mg of sulfur powder, 100 mg of styrene, and 6 mg of zinc diethyldithiocarbamate were placed in a quartz test tube, 2 ml of chloroform was added, and the mixture was irradiated with 365 nm ultraviolet light for 24 h. No obvious reaction was observed.

[0028] Example 13 100 mg of sulfur powder, 100 mg of styrene, and 6 mg of zinc diethyldithiocarbamate were placed in a quartz test tube, 2 ml of toluene was added, and the mixture was irradiated with 365 nm ultraviolet light for 24 h. No obvious reaction was observed.

[0029] Example 14 100 mg of sulfur powder, 100 mg of styrene, and 6 mg of zinc diethyldithiocarbamate were placed in a quartz test tube, and 2 ml of N,N-dimethylformamide was added. The mixture was irradiated with 365 nm ultraviolet light for 24 h, and no obvious reaction was observed.

[0030] Examples 1-3 demonstrate that white light cannot initiate the reaction; ultraviolet light is required. Examples 3-5 show that sulfur and styrene can react in different proportions. Examples 3 and 6-10 demonstrate that the reaction is highly tolerant of accelerators; copolymers of styrene and sulfur can be obtained with different types of accelerators. Examples 11-14 demonstrate that the presence of a solvent will prevent the reaction from proceeding. In all examples, lead acetate test paper was used for monitoring, and no H2S was found to be generated during the reaction.

[0031] Figure 1 No hydrogen atoms were detected in the 1H NMR spectrum of styrene monomer double bonds, proving that styrene had completely reacted; Figure 2 Sulfur-containing polymers were not observed at 3080 cm⁻¹. -1 The left and right C=CH, and can be at 740 cm -1 and 480 cm -1 The observation of CS and SS bonds on the left and right sides respectively indicates that styrene has reacted with sulfur; the melting point of sulfur is generally between 110 and 120℃. Figure 3 No endothermic melting peak of sulfur was detected in the DSC curve, proving that the sulfur had completely reacted; Figure 1-3 Together, they proved that the product contained none of the two reactants, and that the reaction proceeded well. Figure 3 The TG curve shows that the 5% thermogravimetric temperature of the product is 170 °C. Table 1 lists the molecular weight and elemental content of the product in Example 3. The product has a narrow molecular weight distribution and a high sulfur content. The nitrogen element is provided by the accelerator zinc diethyldithiocarbamate.

[0032] Table 1. Molecular weight and elemental content of the product of Example 3 of the present invention

[0033] The above results indicate that styrene reacted successfully with sulfur, without the generation of toxic gas H2S, and a polymer with high sulfur content was obtained.

[0034] Example 15 Rubber composition formulation and its performance testing: The formulations were prepared using S-80 as a reference, respectively, by the method of Example 4 (sample 1, sulfur content 41.247%), the method of Example 3 (sample 2, sulfur content 51.765%), and the method of Example 5 (sample 3, sulfur content 64.562%).

[0035] Table 2. Tread rubber composition formulation

[0036] Table 3. Performance test results of rubber compositions - processing data

[0037] Compared to formulations using sulfur, formulations using polysulfides show a slight increase in Mooney viscosity, a significant increase in scorch time and T90, a decrease in vulcanization rate, and a marked improvement in resistance to reversion.

[0038] Table 4. Performance Test Results of Rubber Compositions - Physical Property Data

[0039] Compared to sulfur-based formulations, polysulfide formulations have slightly lower hardness and 300% modulus, significantly higher elongation at break, and better aging retention.

[0040] Table 5. Performance test results of rubber compositions - dynamic viscoelastic data

[0041] At 0℃, the tanδ of the polysulfide formulation is higher than that of the pure sulfur formulation, while the glass transition temperature is lower. This indicates that the polysulfide formulation has better low-temperature performance than the sulfur formulation.

[0042] Table 6. Performance test results of rubber compositions - abrasion properties

[0043] Compared with the pure sulfur formulation, the polysulfide formulation has improved abrasion performance.

[0044] The above description of the embodiments is only for illustrating the technical concept and features of the present invention. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. Those skilled in the art can obviously easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the above embodiments should not be used to limit the scope of protection of the present invention. All improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A sulfur-containing polymer, characterized in that, The general formula for the structure is as follows: In the formula, n = 1 to 4.

2. The sulfur-containing polymer according to claim 1, characterized in that, The sulfur-containing polymer is copolymerized from styrene, sulfur, and an accelerator through a photocatalytic reaction.

3. A method for preparing a sulfur-containing polymer as described in claim 1 or 2, characterized in that: The sulfur-containing polymer is copolymerized by adding styrene, sulfur, and an accelerator to a quartz test tube or quartz trough and then copolymerizing them under light irradiation at room temperature.

4. The method for preparing a sulfur-containing polymer according to claim 3, characterized in that: The mass ratio of styrene to sulfur is 1:1.5 to 1.5:

1.

5. The method for preparing a sulfur-containing polymer according to claim 3, characterized in that: The accelerator is one or a mixture of two or more of the following: zinc ethyl dithiocarbamate, zinc dibutyl dithiocarbamate, zinc dimethyl dithiocarbamate, 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxodiethylene-2-benzothiazole sulfenamide, N,N'-dicyclohexyl-2-benzothiazole sulfenamide, tetramethylthiuram disulfide, tetramethylthiuram monosulfide, tetraethylthiuram disulfide, pentamethylthiuram hexasulfide, or diphenylguanidine.

6. The method for preparing a sulfur-containing polymer according to claim 3, characterized in that: The amount of the accelerator used is 1-5% of the total mass of styrene and sulfur.

7. The method for preparing a sulfur-containing polymer according to claim 3, characterized in that: The wavelength of the light source for the photocatalytic reaction is 250~400 nm, and the irradiation time is 24~48 h.

8. The use of a sulfur-containing polymer as described in claim 1 or 2 in rubber products.

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