An organic polysulfide, its preparation method and application

Abstract

This invention discloses an organic polysulfide, its preparation method, and its applications. The organic polysulfide has a sulfur content of 45% or more, preferably 50wt%-80wt%, and the organic sulfur composition contains a cyclic trisulfide CnR2nS3. The preparation method of the organic polysulfide includes the following steps: elemental sulfur and unsaturated hydrocarbons react under the catalysis of an alkaline substance. The reaction temperature is controlled by heating the material system containing elemental sulfur, monitoring the viscosity coefficient of the material system, and recording the temperature of the material system as T when the viscosity coefficient gradually increases. The temperature of the material system is controlled to be 0-15°C above T. After the reaction is continued for a period of time, the temperature is lowered, and the liquid material is separated to obtain the sulfur-containing composition. The organic polysulfide not only has a simple and easy-to-control preparation method, but also contains cyclic organic polysulfide compounds with long sulfur chains and a high mass content of cyclic polysulfide compounds.

Description

Technical Field

[0001] This invention relates to an organic polysulfide, its preparation method and application, and more specifically to an organic polysulfide containing a linear structure and a cyclic structure, its preparation method and application. Background Technology

[0002] Organic polysulfides are a class of substances with the general formula RS x -R1 substances, where x is between 2 and 20, R and R1 are alkyl, alkylaryl, aryl or aralkyl functional groups, which can be the same or different, and can be saturated or unsaturated hydrocarbons, or straight-chain, branched or cycloalkanes. Organic polysulfides are often used for the pre-sulfurization treatment of hydrogenation catalysts. Whether it is in-vessel pre-sulfurization or out-of-vessel pre-sulfurization, the activation of the hydrogenation catalyst can only be completed in the presence of a sulfiding agent.

[0003] There are multiple routes for the synthesis of organic polysulfides (OPS). A commonly used method both domestically and internationally involves using thiols and elemental sulfur as raw materials to prepare OPS in the presence of a catalyst. The main development direction of this method is the improvement of traditional catalysts such as amines, alkylamines, alkanolamines, inorganic bases, thiols, and alkoxides. For example, US4876389 uses a catalyst with the general formula RSH·x(C m H 2m The composition of O)·yMOH is used as a catalyst; US5068445 uses an alkaline resin as a catalyst; US6051739 utilizes a traditional alkaline substance and the general formula R2O[CH2CH·(R3)O] nThe combination of SO3M surface-active materials as catalysts improves the yield of the synthesis reaction products and facilitates the separation of the catalyst from the products. US4937385, US6472354, and US6544936 respectively provide methods for preparing organic polysulfides using olefins, sulfur, and hydrogen sulfide as raw materials under different catalyst conditions. The reaction pathway is as follows: first, in the presence of elemental sulfur, hydrogen sulfide reacts with olefins to generate intermediate alkyl thiols. Then, the sulfur molecule undergoes ring-opening upon heating, generating various organic polysulfides with different sulfur atom contents under the presence of a basic catalyst. These methods either use thiols as substrates or generate thiols as intermediates during the reaction. Since most thiols are expensive and toxic compounds with a foul odor, the resulting organic polysulfides have an unpleasant odor due to the dissolution of hydrogen sulfide and unreacted thiols, and exhibit poor stability. US5135670, US5338468, US5849677, and CN200710098327.7 disclose methods for preparing organic polysulfides containing polysulfide crosslinks from olefins and elemental sulfur under different catalysts. These methods are simple, use inexpensive and readily available raw materials, and do not introduce halogens. However, the resulting products contain many impurities, have an unpleasant odor, and have a low sulfur content. US4204969, US5410088, and CN1534019 provide methods for first generating halogen-containing sulfurized olefins from olefins and sulfur halides under different catalysts, followed by dehalogenation to prepare relatively pure polysulfides. These synthetic routes yield products with higher sulfur content under milder conditions, but generate large amounts of wastewater, waste gas (HCl, H2S, etc.), and waste residue (containing NaCl and sulfides), making waste treatment difficult.

[0004] CN103937540A and CN108097333A disclose a sulfiding agent for hydrogenation catalysts and its preparation method. The sulfur content of the sulfiding agent is 40wt%~80wt%, and the sulfiding agent includes linear polysulfides and cyclic sulfides. This method overcomes the problems of high toxicity and high production cost of existing sulfiding agents. However, the proportion of cyclic polysulfides in the sulfiding agent prepared by this method needs to be further increased. The sulfur chain length in cyclic polysulfides is generally less than 2, and 4A molecular sieves need to be added during the preparation process. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an organic polysulfide, its preparation method, and its applications. The organic polysulfide is not only simple and easy to prepare, but also contains cyclic organic polysulfide compounds with long sulfur chains and a high mass content of these cyclic polysulfide compounds.

[0006] An organic polysulfide containing a cyclic trisulfide C n R2n S3, wherein R is any group that can be connected to a carbon atom, generally a hydrogen atom or an alkyl group (preferably methyl); more preferably C3H6S3, and the cyclic trisulfide CnR2nS3 is preferably C3H6S3.

[0007] According to the present invention, the organic polysulfide has a sulfur content of 45% or more, preferably 50wt%-80wt%, and the organic sulfur composition contains linear organic polysulfides and cyclic organic polysulfides. Based on the weight of the organic polysulfide, the mass content of cyclic organic polysulfides in the organic polysulfide is higher than 5wt%, preferably 10%-20%.

[0008] According to the organic polysulfides of the present invention, the cyclic organic polysulfides contain cyclic trisulfides C. n R 2n S3 accounts for 2wt%-15wt% of the total mass of organic polysulfides, preferably 3wt%-10wt%.

[0009] A method for preparing an organic polysulfide mainly includes the following steps: sulfur and unsaturated hydrocarbons react under the catalysis of an alkaline substance. The reaction temperature is controlled by heating the material system containing sulfur, monitoring the viscosity coefficient of the material system, and recording the temperature of the material system as T when the viscosity coefficient gradually increases. The temperature of the material system is controlled to be 0-15℃ higher than T, preferably 3-10℃ higher. After the reaction is continued for a period of time, the temperature is lowered and the liquid material is separated to obtain a sulfur-containing composition.

[0010] According to the method of the present invention, the alkaline substance is added to the material system at least before the viscosity coefficient of the material system changes from gradually decreasing to increasing. It can be added before the material system is heated or during the process of the material system.

[0011] According to the method of the present invention, unsaturated hydrocarbons can be added to the material system all at once, or added intermittently multiple times, or added continuously during the reaction.

[0012] According to the method of the present invention, the gas phase composition in the material system is detected during the continuous reaction process, and the reaction is stopped when the volume content of hydrogen sulfide in the gas phase reaches 1-5%, preferably 2-3%.

[0013] According to the method of the present invention, the preparation of the sulfur-containing composition specifically includes the following steps:

[0014] (1) Heating the material system containing elemental sulfur and alkaline substances to liquefy the elemental sulfur;

[0015] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the temperature of the material system is recorded as T. Introduce unsaturated hydrocarbons and control the temperature of the material system to be 0-15℃ higher than T, preferably 5-10℃ higher.

[0016] (3) After the reaction in step (2) is completed, the temperature is lowered and the liquid material is separated to obtain a sulfur-containing composition.

[0017] According to the method of the present invention, the elemental sulfur mentioned in step (1) is sulfur, which is a solid at room temperature and exists in the form of S8. The sulfur can be a commercially available product or can be prepared according to existing technology. There is no strict limitation on the purity of the sulfur, and the sulfur may contain appropriate amounts of impurities.

[0018] According to the method of the present invention, the alkaline substance in step (1) is used as a catalyst, which can be an organic alkaline substance and / or an inorganic alkaline substance. The alkaline substance includes one or more of methylamine, urea, ethylamine, ethanolamine, ethylenediamine, dimethylamine, trimethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, triethanolamine, butylamine, isobutylamine, tert-butylamine, hexylamine, octylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, potassium tert-butoxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and ammonia water. Preferably, one or more of dimethylamine, trimethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, and triethanolamine are used.

[0019] According to the method of the present invention, the alkaline substance in step (1) can also be a solid alkali, which can be a commercially available product or prepared according to existing technology.

[0020] According to the method of the present invention, the mass ratio of the alkaline substance to elemental sulfur in step (1) is 0.05 to 0.2, preferably 0.01 to 0.1.

[0021] According to the method of the present invention, in step (1), elemental sulfur and an alkaline substance are first mixed and placed in a reaction device, such as a reaction vessel; then, nitrogen gas is used to replace the air before heating. The reaction device is equipped with a stirring device, a heat exchange device (heating or deheating), a viscosity measuring device, a pressure measuring device, a temperature measuring device, etc.

[0022] According to the method of the present invention, the heating rate in step (1) is not particularly limited, but in order to facilitate monitoring of the change in viscosity of the system, the heating rate is generally 0.5-5℃ / min, preferably 1-3℃ / min.

[0023] According to the method of the present invention, the unsaturated hydrocarbon in step (2) is a low-carbon olefin, preferably a low-carbon olefin of C2-C4 olefins. The olefin can be a pure olefin or a mixed olefin. The pure olefin can be any one of propylene, 1-butene, 2-butene, isobutene, n-pentene, and isopentene. The mixed olefin can be any mixture of the above pure olefins, or it can be one or more of liquefied petroleum gas, pre-ether C4, and post-ether C4 that mainly contain mixed olefins.

[0024] According to the method of the present invention, in step (2), unsaturated hydrocarbons are introduced at once, and the molar ratio of the total amount of unsaturated hydrocarbons to elemental sulfur is 1:1 to 1:5, preferably 1:2 to 1:4.

[0025] According to the method of the present invention, the specific viscosity measured in step (2) when the viscosity coefficient of the material system changes from gradually decreasing to increasing will vary with the differences in the material system. Generally, when the viscosity is 3-40 Pa·s, it is preferred to be 5-30 Pa·s.

[0026] According to the method of the present invention, the cooling process in step (3) can adopt conventional cooling methods. The cooled gaseous material can be recycled and reused. The liquid material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. For example, by flash evaporation, generally at 30℃~70℃ and 1000pa~20000pa for 1~2h.

[0027] The aforementioned organic polysulfides can be used as vulcanizing agents for hydrogenation catalysts, additives in rubber production processes, and scorching inhibitors in ethylene production processes.

[0028] The length of the sulfur chain in organic polysulfides (OPS) is a key factor determining their sulfur content and properties, and the ratio of straight-chain to cyclic OPS significantly influences their sulfidation properties. Taking OPS as a sulfiding agent in hydrogenation catalysts as an example, the different decomposition temperatures of OPS and cyclic OPS can be utilized to achieve sustained and slow sulfidation of the catalyst, suppressing the adverse effects of concentrated sulfidation exothermics on the active metal of the hydrogenation catalyst. However, preparing long-chain OPS is quite difficult.

[0029] Based on years of in-depth research on the preparation of organic polysulfides (OPS), the inventors discovered two main reasons for the low concentration of long-chain sulfur free radicals in the reaction system: first, the generation of sulfur free radicals during the reaction stage; long-chain free radicals with two or more sulfur atoms are unstable and prone to further decomposition, resulting in a low content of long-chain sulfur free radicals in the reaction system; second, the reaction equilibrium is affected by factors such as reaction temperature and the concentration of various materials in the later stages of the reaction, leading to further decomposition of the generated long-chain OPS. Guided by these theories, the inventors precisely controlled the reaction process, innovatively proposing to control the reaction temperature by monitoring the viscosity of the material system, enhance the concentration of sulfur trioxide and above free radicals during the reaction to promote the formation of long-chain OPS, and control the termination time by controlling the hydrogen sulfide content in the gaseous products to avoid the decomposition of long-chain OPS. The inventors surprisingly found that through these control methods, not only was the sulfur content in the OPS significantly increased, but the proportion of cyclic compounds also significantly increased, and cyclic trisulfides were discovered in the OPS. Detailed Implementation

[0030] The effects and functions of the method of the present invention are further illustrated below with reference to embodiments and comparative examples, but these embodiments do not constitute a limitation of the present invention. Unless otherwise specified, all percentages (%) in the context of the present invention refer to mass percentages. In the method of the present invention, the composition and sulfur content of the prepared organic polysulfide are determined by GC-MAS. The reaction equipment in the method of the present invention is a reaction vessel, which may be configured as needed with a stirring device, a heat exchange device (heating or deheating), a viscosity measuring device, a pressure measuring device, a temperature measuring device, etc.

[0031] Example 1

[0032] (1) First, sulfur and dimethylamine are mixed at a mass ratio of 0.01 and placed in a reaction vessel; then, the air is replaced with nitrogen and the material system is heated to liquefy the sulfur; the heating rate is 2℃ / min.

[0033] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 20 Pa·s at the lowest point and the temperature is 159℃. Propylene is introduced. The molar ratio of the introduced propylene to elemental sulfur is 1:3. The temperature of the material system is controlled not to exceed 167℃. The reaction is continued for a period of time. During the continuous reaction, the gas phase composition in the material system is detected. When the volume content of hydrogen sulfide in the gas phase reaches 3%, the reaction is stopped.

[0034] (3) After the reaction in step (2) is completed, the gas phase material is cooled down. The cooled gas phase material can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. The sulfurizing agent product is obtained by flash evaporation at 50℃ and 10000pa for 1h. The unreacted olefins are cooled down and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0035] Example 2

[0036] (1) First, sulfur and trimethylamine are mixed at a mass ratio of 0.1 and placed in a reaction vessel; then, the air is replaced with nitrogen and the material system is heated to liquefy the sulfur; the heating rate is 3℃ / min.

[0037] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 5 Pa·s at the lowest point. At this time, the temperature is 155℃. Isobutylene is introduced. The molar ratio of the introduced isobutylene to sulfur is 1:5. The temperature of the material system is controlled not to exceed 165℃. The reaction is continued for a period of time. During the continuous reaction, the gas phase composition in the material system is detected. When the volume content of hydrogen sulfide in the gas phase reaches 4%, the reaction is stopped. After the reaction in step (2) is completed, the temperature is lowered. The gas phase material after cooling can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. By flash evaporation, the sulfurizing agent product is obtained by flash evaporation at 30℃ and 20000 Pa for 2 hours. The unreacted olefins are cooled and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0038] Example 3

[0039] (1) First, sulfur and diethylamine are mixed at a mass ratio of 0.08 and placed in a reaction vessel; then, the air is replaced with nitrogen and the material system is heated to liquefy the sulfur; the heating rate is 2℃ / min.

[0040] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 30 Pa·s at the lowest point. At this time, the temperature is 161℃. 1-Butene is introduced. The molar ratio of the introduced 1-butene to elemental sulfur is 1:2. The temperature of the material system is controlled not to exceed 166℃. The reaction is continued for a period of time. During the continuous reaction, the gas phase composition in the material system is detected. When the volume content of hydrogen sulfide in the gas phase reaches 2%, the reaction is stopped.

[0041] (3) After the reaction in step (2) is completed, the gas phase material is cooled down. The cooled gas phase material can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. The sulfurizing agent product is obtained by flash evaporation at 70℃ and 1000pa for 1.5h. The unreacted olefins are cooled down and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0042] Example 4

[0043] (1) First, the mixture of elemental sulfur, triethylamine and propylamine (the mass ratio of triethylamine to propylamine is 1:2) is mixed at a mass ratio of 0.04 and placed into the reactor; then, the air is replaced with N2 gas and the material system is heated to liquefy the elemental sulfur; the heating rate is 2℃ / min.

[0044] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 20 Pa·s at the lowest point and the temperature is 156℃. A mixture of propylene and isobutylene (the molar ratio of propylene to isobutylene is 1:2) is introduced. The molar ratio of the mixture of propylene and isobutylene to elemental sulfur is 1:3. The temperature of the material system is controlled not to exceed 164℃. The reaction is continued for a period of time. During the continuous reaction, the gas phase composition in the material system is detected. When the volume content of hydrogen sulfide in the gas phase reaches 3%, the reaction is stopped.

[0045] (3) After the reaction in step (2) is completed, the gas phase material is cooled down. The cooled gas phase material can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. The sulfurizing agent product is obtained by flash evaporation at 50℃ and 10000pa for 2 hours. The unreacted olefins are cooled down and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0046] Example 5

[0047] (1) First, the mixture of elemental sulfur, isopropylamine and 1,3-propanediamine (the mass ratio of isopropylamine to 1,3-propanediamine is 3:1) is mixed at a mass ratio of 0.05 and placed in the reactor; then, the air is replaced with N2 gas and the material system is heated to liquefy the elemental sulfur; the heating rate is 2℃ / min.

[0048] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 20 Pa·s at the lowest point. At this time, the temperature is 158℃. Introduce n-pentene. The molar ratio of n-pentene to sulfur is 1:3. Control the temperature of the material system to not exceed 166℃. Continue the reaction for a period of time. During the continuous reaction, detect the gas phase composition in the material system. Stop the reaction when the volume content of hydrogen sulfide in the gas phase reaches 3%.

[0049] (3) After the reaction in step (2) is completed, the gas phase material is cooled down. The cooled gas phase material can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. The sulfurizing agent product is obtained by flash evaporation at 50℃ and 10000pa for 2 hours. The unreacted olefins are cooled down and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0050] Example 6

[0051] (1) First, the mixture of elemental sulfur, tripropylamine and 1,2-propanediamine (the mass ratio of tripropylamine to 1,2-propanediamine is 1:1) is mixed at a mass ratio of 0.08 and placed in the reactor; then, the air is replaced with N2 gas and the material system is heated to liquefy the elemental sulfur; the heating rate is 2℃ / min.

[0052] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 15 Pa·s at the lowest point. At this time, the temperature is 158℃. Isoprene is introduced. The molar ratio of the introduced isopentene to elemental sulfur is 1:3. The temperature of the material system is controlled not to exceed 167℃. The reaction is continued for a period of time. During the continuous reaction, the gas phase composition in the material system is detected. When the volume content of hydrogen sulfide in the gas phase reaches 3%, the reaction is stopped.

[0053] (3) After the reaction in step (2) is completed, the gas phase material is cooled down. The cooled gas phase material can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. The sulfurizing agent product is obtained by flash evaporation at 50℃ and 10000pa for 2 hours. The unreacted olefins are cooled down and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0054] Example 7

[0055] (1) First, sulfur and dimethylamine are mixed at a mass ratio of 0.05 and placed in a reaction vessel; then, the air is replaced with N2 gas and the material system is heated to liquefy the sulfur; the heating rate is 2℃ / min.

[0056] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 20 Pa·s at the lowest point. At this time, the temperature is 157℃. Ether-containing C4 is introduced. The molar ratio of the ether-containing C4 to the sulfur element is 1:3. The temperature of the material system is controlled not to exceed 165℃. The reaction is continued for a period of time. During the continuous reaction, the gas phase composition in the material system is detected. When the volume content of hydrogen sulfide in the gas phase reaches 3%, the reaction is stopped.

[0057] (3) After the reaction in step (2) is completed, the gas phase material is cooled down. The cooled gas phase material can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. The sulfurizing agent product is obtained by flash evaporation at 50℃ and 10000pa for 2 hours. The unreacted olefins are cooled down and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0058] Example 8

[0059] (1) First, sulfur and diethylamine are mixed at a mass ratio of 0.04 and placed in a reaction vessel; then, the air is replaced with N2 gas and the material system is heated to liquefy the sulfur; the heating rate is 2℃ / min.

[0060] (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the viscosity is 20 Pa·s at the lowest point and the temperature is 158℃. Introduce pre-ether C4. The molar ratio of the introduced pre-ether C4 to the sulfur element is 1:3. Control the temperature of the material system to not exceed 166℃. Continue the reaction for a period of time. During the continuous reaction, detect the gas phase composition in the material system. Stop the reaction when the volume content of hydrogen sulfide in the gas phase reaches 3%.

[0061] (3) After the reaction in step (2) is completed, the gas phase material is cooled down. The cooled gas phase material can be recycled and reused. The liquid phase material is separated by flash evaporation or distillation to obtain a sulfur-containing composition. The sulfurizing agent product is obtained by flash evaporation at 50℃ and 10000pa for 2 hours. The unreacted olefins are cooled down and recycled. The analysis results of the obtained sulfurizing agent product are shown in Table 1.

[0062] Table 1. Analysis Results of Vulcanizing Agent Products

[0063]

Claims

1. A method for preparing an organic polysulfide, wherein, The organic polysulfide contains cyclic trisulfides; the sulfur content of the organic polysulfide is 45% or more; the organic sulfur composition contains linear organic polysulfides and cyclic organic polysulfides; based on the weight of the organic polysulfide, the mass content of cyclic organic polysulfides in the organic polysulfide is higher than 5 wt%; the cyclic trisulfides contained in the cyclic organic polysulfide account for 2 wt%-15 wt% of the total mass of the organic polysulfide. The method includes the following steps: sulfur and unsaturated hydrocarbons react under the catalysis of an alkaline substance. The reaction temperature is controlled as follows: the material system containing sulfur is heated, and the viscosity coefficient of the material system is monitored. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the temperature of the material system at this point is recorded as T. The temperature of the material system is controlled to be 0-15℃ higher than T. After the reaction is continued for a period of time, the temperature is lowered and the liquid material is separated to obtain a sulfur-containing composition. During the continuous reaction, the gas phase composition of the material system is detected. When the volume content of hydrogen sulfide in the gas phase reaches 1-5%, the reaction is stopped.

2. The method according to claim 1, characterized in that: Control the temperature of the material system to be 3-10℃ higher than T.

3. The method according to claim 1, characterized in that: The alkaline substance is added before the material system is heated or during the material system process.

4. The method according to claim 1, characterized in that: The gas phase composition of the material system is monitored during the continuous reaction process, and the reaction is stopped when the volume content of hydrogen sulfide in the gas phase reaches 2-3%.

5. The method according to claim 1, characterized in that: The preparation of the sulfur-containing composition specifically includes the following steps: (1) Heating the material system containing elemental sulfur and alkaline substances to liquefy the elemental sulfur; (2) Measure the viscosity coefficient of the material system. When the viscosity coefficient of the material system changes from gradually decreasing to increasing, the temperature of the material system is recorded as T. Introduce unsaturated hydrocarbons and control the temperature of the material system to be 0-15℃ higher than T. (3) After the reaction in step (2) is completed, the temperature is lowered and the liquid material is separated to obtain a sulfur-containing composition.

6. The method according to claim 5, characterized in that: In step (2), the temperature of the material system is controlled to be 5-10℃ higher than T.

7. The method according to claim 5, characterized in that: The alkaline substance mentioned in step (1) includes one or more of the following: methylamine, urea, ethylamine, ethanolamine, ethylenediamine, dimethylamine, trimethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, triethanolamine, butylamine, isobutylamine, tert-butylamine, hexylamine, octylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, potassium tert-butoxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and ammonia water.

8. The method according to claim 7, characterized in that: The alkaline substance mentioned in step (1) is one or more of dimethylamine, trimethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, and triethanolamine.

9. The method according to claim 5, characterized in that: The alkaline substance mentioned in step (1) is a solid alkali.

10. The method according to claim 5, characterized in that: The mass ratio of the alkaline substance to elemental sulfur in step (1) is 0.05 to 0.

2.

11. The method according to claim 10, characterized in that: The mass ratio of the alkaline substance to elemental sulfur in step (1) is 0.01 to 0.

1.

12. The method according to claim 5, characterized in that: In step (1), sulfur and alkaline substances are first mixed and placed into the reaction equipment; then nitrogen gas is used to replace the air before heating.

13. The method according to claim 5, characterized in that: The heating rate in step (1) is 0.5-5℃ / min.

14. The method according to claim 13, characterized in that: The heating rate in step (1) is 1-3℃ / min.

15. The method according to claim 5, characterized in that: The unsaturated hydrocarbons mentioned in step (2) are low-carbon olefins.

16. The method according to claim 15, characterized in that: The unsaturated hydrocarbons mentioned in step (2) are low-carbon olefins of C2-C4 olefins.

17. The method according to claim 15, characterized in that: The olefin is a pure olefin or a mixed olefin. The pure olefin is any one of propylene, 1-butene, 2-butene, isobutene, n-pentene, and isopentene. The mixed olefin is any mixture of the pure olefins, or one or more of liquefied petroleum gas, pre-ether C4, and post-ether C4 that mainly contain mixed olefins.

18. The method according to claim 5, characterized in that: In step (2), unsaturated hydrocarbons are introduced at once, and the total amount of unsaturated hydrocarbons introduced is in a molar ratio of 1:1 to 1:5 to elemental sulfur.

19. The method according to claim 18, characterized in that: In step (2), the total amount of unsaturated hydrocarbons introduced is in a molar ratio of 1:2 to 1:4 to sulfur.

20. The method according to claim 5, characterized in that: In step (2), the viscosity of the material system changes from gradually decreasing to increasing when the viscosity is 3-40 Pa·s.

21. The method according to claim 20, characterized in that: In step (2), the viscosity of the material system changes from gradually decreasing to increasing when the viscosity is 5-30 Pa·s.

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