Process for preparing a sulfur copolymer

Abstract

A process for preparing a sulfur copolymer, a sulfur copolymer and a polymer composition comprising one or more sulfur copolymers is provided. The process comprises the step of copolymerizing a cyclic monothiocarbonate compound of formula (I) with elemental sulfur in the presence of a polymerization initiator, wherein R 1 and R 2 are independently of each other hydrogen, C1-C 18 alkyl, C1-C 18 alkyl substituted by halogen or interrupted by O or S; C6-C 18 aryl or C6-C 12 aryl substituted by C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio or halogen.

Description

[0001] This invention relates to a method for preparing sulfur copolymers by copolymerizing a 5-membered cyclic monothiocarbonate compound with elemental sulfur in the presence of a polymerization initiator, the sulfur copolymers obtained by said method, and a composition comprising one or more sulfur copolymers. Background of the Invention

[0003] Sulfur plays a vital role in many applications in the chemical industry.

[0004] The vulcanization of rubber is made possible by using it as a crosslinking agent. The brand name Crystex (Eastman) uses polymerized sulfur as a vulcanizing agent for rubber.

[0005] Because organic polysulfides are excellent carriers for transporting sulfur to reaction sites, they have become the preferred source of sulfur. G. Carroll, Phosphorus, Sulfur and Silicon, 1994, 95-96, 517-518 describe various applications of polysulfides.

[0006] For example, polysulfides are used in the lubrication industry to prevent metals from melting under extreme load conditions by forming a protective layer on their surfaces. An advantage of using them as extreme pressure additives is that they do not contain olefins, chlorine, or color-producing trithiophenes.

[0007] Dimethyl disulfide can be used as a pre-sulfurizing agent to increase the lifetime of metal oxide-based catalysts in the petroleum industry. Dimethyl disulfide can also be used as a sulfur solvent in the oil and gas industry.

[0008] JJ Griebel et al., Progr. Polym. Sci., 58, 2016, 90-125, describe sulfur-containing polymeric materials derived from S8, thus exhibiting a high degree of sulfur bonding, i.e., a high SS bond level, in this polymeric structure. Polysulfides—a class of high-sulfur polymers—have structures similar to polymeric sulfur but with improved stability and processability. Polysulfides can be synthesized directly from elemental sulfur through condensation, free radical, and ionic copolymerization reactions.

[0009] Polysulfide rubbers are condensation products of organic dihalides and alkali metal polysulfides, such as those known under the brand name Thiokol and used as elastomers for sealants. They can be liquid polymers and optionally crosslinked by oxidizing the terminal SH groups of the polymer to disulfides.

[0010] Anionic copolymerization of propylene sulfide with elemental sulfur initiated by sodium thiophene was described, for example, by A. Duda et al., Macromolecules, 1982, 15, 36-40. The sulfur content was described to be at most 85% by weight, i.e., -[CH2CH(CH3)S zThe copolymers in which the z-average value is at most 8.

[0011] A. Duda et al., Macromol. Chem., Rapid Commun., 1988, 9, 151-157, described the anionic low molecular weight copolymerization of S8 with cyclic sulfides in the presence of symmetrical di(hydroxyalkyl)polysulfides, yielding a number-average molecular weight M n Liquid α,ω-oligomeric diols with a concentration of 700-2500 g / mol and containing up to 80% by weight of chemically linked sulfur.

[0012] Cationic bulk copolymerization is known from M. Schmidt et al., Angew. Chem. Int. Ed., 1978, 17, 51-52, which yields linear polysulfides by ring-opening of cyclic sulfur-containing comonomers with Lewis acids.

[0013] In a process known as desulfurization, S8 is used as a reaction medium and comonomer, as described for example by JJ Griebel et al., Progr. Polym. Sci., 58, 2016, 90-125, which provides a statistical copolymer poly(sulfur-random-(1,3-diisopropenylbenzene)) in bulk copolymerization with S8.

[0014] US 2014 / 0199592 A1 discloses polymer compositions comprising sulfur and copolymers of one or more monomers such as diisopropylbenzene or propylene sulfide. For example, it describes tetraphenylchlorination in toluene using benzyl dithiobenzoate as an initiator. Sulfur / sulfurized propylene copolymer was prepared by thioacryl transfer polymerization, yielding a pale red oily polymer.

[0015] US 5929202 A discloses a method for preparing ethylene vulcanizate / sulfur copolymers by polymerizing ethylene vulcanizate and sulfur in the presence of a polymerization initiator, such as an aliphatic tertiary amine like DABCO (1,4-diazabicyclo[2.2.2]octane) or tetrabutylammonium acetate, and a solvent. These copolymers are described as potential applications as vulcanizing agents and accelerators in high-quality tire rubber or as industrial elastomers. However, the use of ethylene vulcanizate or propylene vulcanizate should be avoided due to their low storage stability.

[0016] Introducing high levels of SS bonds into polymers provides a pathway to obtaining materials with suitable properties because these structures are redox-active, highly polarizable, impart high refractive indices, and exhibit dynamic covalent characteristics. Therefore, organic polysulfides play an important role in various industries.

[0017] Many methods for preparing organic polysulfides have shown drawbacks. For example, halogenated precursors pose a risk of halogen contamination in the product. The use of olefins poses a risk of residual olefins in the product. In the case of cyclic sulfide-derived polysulfides, the synthesis is based on high-energy starting materials that are typically unavailable.

[0018] Therefore, there is still a need for an readily available synthetic route for preparing organosulfur polymers that can be industrially produced.

[0019] In addition, there is a need for readily available copolymers with the required adjustable sulfur content, suitable for use in optical applications, sealant applications, sulfur immobilization in polymer matrices, as metalworking fluids, and / or as active materials in Li-S batteries.

[0020] Therefore, the object of the present invention is to provide a method for preparing sulfur copolymers that is both economical and flexible.

[0021] Furthermore, the object of the present invention is to provide a method for preparing sulfur copolymers using an S-containing monomer that has improved storage stability compared to ethylene sulfide or propylene sulfide.

[0022] Furthermore, an object of the present invention is to provide a sulfur copolymer with a high refractive index, which is suitable for, for example, optical applications.

[0023] Furthermore, the object of the present invention is to provide a sulfur copolymer having a high sulfur content and / or high viscosity, which is suitable, for example, for use as a metalworking fluid. Invention Overview

[0025] It has been found that sulfur copolymers can be readily prepared by reacting cyclic monothiocarbonate compounds with elemental sulfur in the presence of a polymerization initiator. This method for preparing sulfur copolymers particularly provides the availability of copolymers with desired sulfur content, which can be adjusted and thus suitable for use in optical applications, sealant applications, sulfur immobilization in polymer matrices, as metalworking fluids, and / or as active materials in Li-S batteries.

[0026] Therefore, in a first aspect, the present invention relates to a method for preparing a sulfur copolymer, the method comprising making the following formula (I) The step of polymerizing a cyclic monothiocarbonate compound with elemental sulfur in the presence of at least one polymerization initiator, wherein R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

[0027] Another aspect of the invention relates to sulfur copolymers that can be obtained by methods defined in any aspect herein.

[0028] Another aspect of the present invention relates to a set of n formulas (II) A sulfur copolymer of an alkylene unit and (n+1) polysulfide units, wherein the polysulfide units comprise a total of (2n+1) to (2n+9) sulfur atoms, n≥1, and R 1 and R 2 As defined in any respect herein.

[0029] Another aspect of the invention relates to a polymer composition comprising one or more sulfur copolymers as defined herein in any respect. Invention Details

[0031] The terms alkyl, alkoxy, alkylthio, aryl, and halogen are known in the art and generally have the following meanings, unless the group is further specified in the specific embodiments described below:

[0032] If possible, alkyl groups, such as C1-C 18 Alkyl, C1-C8 alkyl, or C1-C4 alkyl, may be linear or branched within a given limit of carbon atoms. Examples are methyl (Me), ethyl (Et), n-propyl, isopropyl, n-butyl, 1-methylpropyl, 2-methylpropyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethylpropyl, n-hexyl, 1-methylhexyl, n-heptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecanyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and structural isomers of the above n-alkyl groups.

[0033] Any alkyl group having more than one, especially more than two, carbon atoms, or such alkyl structural moiety being part of another structural moiety, may be spaced by heterofunctional groups such as -O- or -S-. They may be spaced by one or more of these heterofunctional groups, in each case one group typically inserts into one C-C bond of the alkyl group. If the spaced group is additionally substituted, the substituent is usually not located at the heteroatom. If two or more spacer groups of type -O- or -S- appear in a group, they are generally identical.

[0034] Alkoxy groups, such as C1-C4 alkoxy groups, are alkyl-O.

[0035] Alkylthio groups, such as C1-C4 alkylthio groups, are alkyl-S.

[0036] Aryl, for example C6-C18 Aryl or C6-C 12 The aryl group can be phenyl, fluorenyl, biphenyl, terphenyl, or naphthyl within a given limit of carbon atoms, and they can have fused rings, as in indenyl. Preferred examples are phenyl, 1-naphthyl, 2-naphthyl, 3-, or 4-biphenyl. Each aryl group can be unsubstituted or substituted once or multiple times.

[0037] Halogen (Hal) is represented by I, Br, Cl or F, preferably Cl on an alkyl group and Cl or Br on an aryl group.

[0038] Substituent "C 12 / 14 "" refers to the derivative of C 12 / C 14 Substituents in fatty alcohols.

[0039] The term "substituted" means "substituted once or more," i.e., 1 to 3 times, preferably 1 or 2 times, more preferably 1 time. If the substituent appears more than once in the group, it can be different each time it appears.

[0040] The term "sulfur copolymer" as used herein includes oligomers and polymers having at least two polysulfide units and at least one alkylene unit, provided that at least one SS bond is present. (IVa) or formula The terminal units of (IVb) are generally not included in the definition of this sulfur copolymer.

[0041] The term “polysulfide unit” as used in this article includes thioether groups and polysulfide groups having at least two sulfur atoms (S2).

[0042] As used in this article, the singular forms of the articles “a,” “a kind,” and “the” include the plural forms, unless the content explicitly states otherwise.

[0043] The method of the present invention typically provides a mixture of one or more sulfur copolymers.

[0044] Therefore, in another aspect, the present invention relates to a method for preparing a polymer composition comprising one or more sulfur copolymers, the method comprising making the following... (I) The step of polymerizing a cyclic monothiocarbonate compound with elemental sulfur in the presence of at least one polymerization initiator, wherein R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen12 Aryl.

[0045] In a preferred aspect, the present invention relates to a method for preparing a sulfur copolymer, wherein R 1 and R 2 Independently hydrogen, C1-C4 alkyl, halogenated, or C1-C separated by O or S 18 Alkyl; C6-C 12 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

[0046] More preferably, a method for preparing a sulfur copolymer, wherein the cyclic monothiocarbonate compound of formula (I) is of formula (I) cyclic monothiocarbonate compounds, wherein R 2 It is hydrogen, C1-C4 alkyl, halogenated or C1-C8 alkyl separated by O or S; or phenyl.

[0047] Therefore, in a more preferred aspect, the present invention relates to a method for preparing a sulfur copolymer, wherein R 1 It is hydrogen and R 2 It is hydrogen, C1-C4 alkyl, halogenated or C1-C8 alkyl separated by O or S; or phenyl.

[0048] Preferably, the cyclic monothiocarbonate compound of formula (V) to be reacted in the method of the present invention, wherein R 2 It is hydrogen, C1-C4 alkyl, or C1-C8 alkyl that is substituted with halogen or separated by O.

[0049] More preferably, the cyclic monothiocarbonate compound of formula (V) to be reacted in the method of the present invention, wherein R 2 It is hydrogen, C1-C4 alkyl, or C1-C6 alkyl separated by O.

[0050] A method for preparing sulfur copolymers is particularly preferred, wherein R 1 It is hydrogen and R 2 It is hydrogen or C1-C4 alkyl.

[0051] A method for preparing sulfur copolymers is particularly preferred, wherein R 1 It is hydrogen and R 2 It is a C1-C4 alkyl group.

[0052] Suitable examples of cyclic monothiocarbonate compounds of formula (V) include those of formula (V).

[0053] (Vf) cyclic monothiocarbonate.

[0054] One or more compounds of formula (I), preferably one or more compounds of formula (V), can be used in the method of the present invention.

[0055] The method preferably uses a compound of formula (I), and more preferably a compound of formula (V).

[0056] The method using the compound of formula (Vb) is particularly preferred.

[0057] A method that uses a mixture of two different compounds of formula (I) is also preferred. A method that uses a mixture of two different compounds, wherein the mixture comprises a compound of formula (Va) or a compound of formula (Vb), is even more preferred.

[0058] A method further preferably using a mixture of compounds of formula (Va) and formula (Vb) is preferred. A method even more preferred in which compound (Vb) is used in an amount greater than 50% by weight based on the total weight of the mixture of compounds of formula (Va) and formula (Vb).

[0059] Cyclic monothiocarbonate compounds of formula (I) or (V) can be prepared according to the methods described in US 3072676, US 3201416 or WO2019 / 034469 A1.

[0060] The cyclic monothiocarbonate compound of formula (I) is typically liquid at 21°C and 1 bar. When the cyclic monothiocarbonate compound of formula (I) is solid at 21°C and 1 bar, the compound can be used in a stable molten form at the polymerization temperature.

[0061] Suitable sulfur sources can be sulfur recovered from hydrogen sulfide produced as a feedstock in petroleum refining processes or sulfur present in nature. Suitable sulfur sources can be sublimated sulfur, precipitated sulfur, sulfur blooms, and colloidal sulfur.

[0062] Elemental sulfur can be provided in powder form. Under ambient conditions, elemental sulfur exists primarily in the form of an 8-membered ring (S8), which melts at temperatures ranging from 120 to 124 °C and undergoes equilibrium ring-opening polymerization of the S8 monomer above 159 °C to yield linear polysulfides with dual free radical ends.

[0063] S8, typically the most stable and cheapest raw material, is used in the methods of this invention. However, many other allotropes of sulfur can be used, such as other cyclic allotropes derived from S8 through melt thermal processing. Any sulfur substance that produces a di-free radical or anionic polymer upon heating can be used in the methods of this invention.

[0064] The method for preparing sulfur copolymers is typically carried out by copolymerizing a cyclic monothiocarbonate compound of formula (I) with elemental sulfur in the presence of a polymerization initiator.

[0065] The reaction can be initiated using virtually any type of polymerization initiator, typically one that can be used for anionic, cationic, or coordination polymerization. Anionic polymerization initiators are preferred.

[0066] Examples of anionic polymerization initiators include metal salts of amine bases, organophosphorus compounds, mercapto compounds, metal alkoxides, and basic inorganic compounds, with basic inorganic salts being preferred.

[0067] Examples of amine bases include compounds having a tertiary amino group, a guanidine group, or an amidine group.

[0068] Examples of compounds having a tertiary amino group include trimethylamine, triethylamine, tributylamine, 2,4,6-tris(dimethylaminomethyl)phenol, pyridine, 1,4-diazabicyclo[2.2.2]octane (DABCO), tetramethylethylenediamine, and dimethylaminopyridine (DMAP).

[0069] Examples of compounds having a guanidine group include guanidine (1,5,7-triazabicyclodecene (TBD)).

[0070] Examples of compounds having an amidine group include diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and N-methyl-1,5,7-triazabicyclododecene (MTBD).

[0071] Examples of organophosphine compounds include triphenylphosphine or tributylphosphine.

[0072] Examples of metal alkoxides include sodium methoxide.

[0073] Examples of metal salts of thiol compounds include sodium thiomethoxide, sodium thiophene, or sodium salts of 2-mercaptobenzothiazole.

[0074] Organothiols, such as mono-, di-, or polythiols, can be added as initiators to the copolymerization reaction. These thiols are typically added together with organic bases, such as compounds with amine or amidine groups, like DBU, DBN, or MTBD. The thiols can be introduced and retained as a covalently bonded portion of the copolymer.

[0075] Suitable examples of monothiol compounds are C1-C 12 Alkyl thiols and aryl thiols such as thiophenol.

[0076] Examples of suitable dithiol compounds include 1,2-dimercaptoethane, 2,2-dimercaptopropane, 1,3-dimercaptopropane, 1,4-dimercaptobutane, 1,6-dimercaptohexane, tetraethylene glycol dithiol, 3,6-dioxa-1,8-octanedithiol, 2,2'-thiodiethylthiol, 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, and 4,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane. 9-Trithiaundecane, 5,7-dimercaptomethyl-1,11-dimercapto-3,6,9-trithiaundecane, 1,1,3,3-tetra(mercaptomethylthio)propane, 1,2-di(2-mercaptoethylthio)ethane, 1,5-dimercapto-3-oxapentane, 2,2-dimethylpropane-1,3-dithiol, 2-mercaptomethyl-1,3-dimercaptopropane, benzenedimethylthiol (isomer), (1,1'-biphenyl)-4,4'-dimethylthio Alcohols, 2-mercaptoethyl ethers, dimercaptobenzene (isomers), terphenyl dithiol, 1,4-di(mercaptomethyl)cyclohexane, 1,4-dimercaptocyclohexane, di(4-mercaptophenyl) sulfide, di(4-mercaptophenyl) ether, 2-mercaptomethyl-1,4-dimercaptopropane, 2-(2-mercaptoethylthio)-1,3-dimercaptopropane, 1,2-di(2-mercaptoethylthio)-3-mercaptopropane, ethylene glycol dithioglycolate, ethylene glycol di(2-mercaptoethyl)-3-mercaptopropane 2,4-butanediol di(2-mercaptoacetate), ethylene glycol di(3-mercaptopropionate), 1,4-butanediol di(3-mercaptopropionate), 2,5-di(mercaptomethyl)-1,4-dithiane, 2,5-di(mercaptoethyl)-1,4-dithiane, 2,2-di(4-mercaptophenyl)propane, di(4-mercaptomethylphenyl) sulfide, di(4-mercaptomethylphenyl) ether, and 2,2-di(4-mercaptomethylphenyl)propane.

[0077] Examples of suitable trithiol compounds include 1,3,5-trimercaptobenzene, 1,3,5-tris(mercaptomethyl)benzene, trimethylolpropane tris(3-mercaptopropionate), trimethylolpropane tris(thioglycolate), 1,2,3-trimercaptopropane, trimethylolpropane tris(2-mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), and 1,1,1-tris(mercaptomethyl)propane.

[0078] Examples of suitable tetrathiols include pentaerythritol tetra(thioglycolate), pentaerythritol tetra(2-mercaptoacetate), pentaerythritol tetra(3-mercaptopropionate), 1,1,3,3-tetra(mercaptomethylthio)propane, and tetra(mercaptomethyl)methane.

[0079] The total weight of the organothiol compound based on elemental sulfur and the cyclic monothiocarbonate compound of formula (I) can be added to the copolymerization reaction in an amount of up to 10% by weight, preferably up to 5% by weight.

[0080] Examples of basic inorganic compounds include basic zeolites, metal oxides, metal hydroxides, metal sulfides including ammonium sulfide, hydrotalcite, and basic clays.

[0081] Preferably, the basic inorganic compound is an inorganic salt selected from metal hydroxides, metal sulfides, ammonium sulfide, metal hydrogen sulfides, metal oxides, metal phosphates, or metal silicates. The term "sulfide" includes inorganic salts of the formula (S... p ) 2- Mono-, oligo-, and polysulfides, wherein p is an integer from at least 1 to 10. The term "hydrosulfide" includes those of the formula (HS). q ) 1- Mono-, oligo-, and polyhydrosulfides, wherein q is an integer from at least 1 to 10.

[0082] More preferably, the basic inorganic compound is an inorganic salt selected from metal hydroxides, metal sulfides, ammonium sulfide, or metal hydrogen sulfides. The cation of the inorganic salt is preferably a cation having one or two positive charges, such as an alkali metal or alkaline earth metal cation, more preferably an alkali metal cation such as sodium or potassium.

[0083] Examples of particularly preferred inorganic salts are NaOH, KOH, NaSH, and (NH4)2S. p Na2S p and K2S p , where p is 1-10.

[0084] Examples of cationic polymerization initiators include Lewis acids such as titanium tetrachloride, aluminum chloride, or boron trifluoride diethyl ether complexes.

[0085] Examples of coordination polymerization initiators include metal compounds such as diethylzinc, zinc acetate, triethylaluminum, zinc dimethyldithiocarbamate, and zinc diethyldithiocarbamate.

[0086] Preferably, the polymerization initiator is an anionic polymerization initiator selected from metal salts containing amine bases, organophosphorus compounds, mercapto compounds, and basic inorganic salts.

[0087] Therefore, the present invention relates, in a preferred aspect, to a method for preparing a sulfur copolymer, wherein the polymerization initiator is an anionic polymerization initiator selected from metal salts containing amine bases, organophosphorus compounds, mercapto compounds, and basic inorganic salts.

[0088] More preferably, the polymerization initiator is selected from amine-containing bases, organophosphorus compounds and basic inorganic salts, and more preferably anionic polymerization initiators of basic inorganic salts.

[0089] Examples of amine bases are preferably compounds having a tertiary amino group, a guanidine group, or an amidine group.

[0090] Therefore, the most preferred anionic polymerization initiator is an anionic polymerization initiator selected from compounds containing amine bases—compounds having tertiary amino, guanidine, or amidine groups, organophosphorus compounds, and basic inorganic salts, wherein the basic inorganic salt is selected from NaOH, KOH, NaSH, (NH4)2S. p Na2S p or K2S p , where p is 1-10.

[0091] Therefore, the present invention relates, in a preferred aspect, to a method for preparing a sulfur copolymer, wherein the polymerization initiator is an anionic polymerization initiator selected from amine bases, organophosphorus compounds and basic inorganic salts, preferably basic inorganic salts.

[0092] In another preferred aspect, the present invention relates to a method for preparing a sulfur copolymer, wherein the anionic polymerization initiator is a basic inorganic salt.

[0093] The preferred polymerization initiator is a basic inorganic salt, selected from NaOH, KOH, NaSH, and Na2S. p (NH4)2S p or K2S p , where p is 1-10.

[0094] The polymerization initiator can be used in a catalytically effective amount, for example, in an amount of 0.01-0.5 mol, preferably 0.02-0.3 mol, based on 1 mol of elemental sulfur S8.

[0095] If necessary, a viscosity modifier can be added to the method of the present invention. Such viscosity modifiers are known in the art. Preferably, no viscosity modifier is added.

[0096] This method is typically carried out under an inert atmosphere at elevated temperatures, such as 40–230 °C (the copolymerization temperature). The copolymerization reaction can be carried out in a solvent or without a solvent.

[0097] Therefore, the present invention preferably relates to a method for preparing a sulfur copolymer, wherein the copolymerization step is carried out at a temperature in the range of 40-230°C.

[0098] When using solvents, the copolymerization step is typically carried out at temperatures in the range of 40-180°C, preferably 60-160°C.

[0099] Without the use of solvents, this copolymerization step is typically carried out at a temperature in the range of approximately 120-230°C.

[0100] The reaction time for this copolymerization step can vary from 0.5 to 8 hours, preferably from 1 to 6 hours.

[0101] Therefore, a preferred method is one in which the copolymerization step is carried out at an elevated temperature for 0.5-8 hours in the presence of an anionic polymerization initiator, wherein when the method is carried out with a solvent, the temperature is in the range of 40-180°C, particularly 60-160°C, or wherein when no solvent is used, the temperature is in the range of 120-230°C.

[0102] If present, the solvent can be an organic solvent.

[0103] Examples of suitable organic solvents are ketones such as acetone, butanone, cyclohexanone, or methyl isobutyl ketone; aromatic solvents such as benzene, toluene, or xylenes; and ethers such as tetrahydrofuran (THF), dimethyl ethyl ketone, etc. Alkanes, dioxolane, or ethylene glycol dimethyl ether; esters such as ethyl acetate or butyl acetate; amides such as dimethylformamide (DMF) or N-methylpyrrolidone (NMP); aliphatic hydrocarbons such as hexane or cyclohexane; halogenated solvents such as chloroform; alcohols such as ethanol, isopropanol, ethylene glycol ether, or propylene glycol monomethyl ether; and carbon disulfide. Ketones, ethers, and carbon disulfide are preferred. The solvent can be used alone or in combination of two or more of these solvents.

[0104] The solvent can be used in an amount that causes the raw material element sulfur, the polymerization initiator and the cyclic monothiocarbonate compound of formula (I) to form a mixture having 20-60% by weight of solids based on the total weight of the solvent and the raw material.

[0105] The order in which the feedstock containing elemental sulfur, the monothiocarbonate compound of formula (I), the polymerization initiator, and optionally the solvent and the organothiol compound are added to the reactor can be changed to affect the desired structure of the sulfur copolymer.

[0106] The mixture containing the raw materials can be a suspension, solution, or solid mixture at room temperature at the start of the reaction, depending on the type of raw materials.

[0107] For example, elemental sulfur and cyclic monothiocarbonate compounds of formula (I) can be added simultaneously or alternately to the polymerization initiator at the copolymerization temperature.

[0108] Alternatively, a portion of elemental sulfur or the cyclic monothiocarbonate compound of formula (I) can be provided as a mixture with an anionic polymerization initiator at room temperature (approximately 20-25°C). The remaining portion of elemental sulfur or the cyclic monothiocarbonate compound of formula (I) can be added at the copolymerization temperature. At the copolymerization temperature, elemental sulfur is preferably added dropwise in molten form or in small portions.

[0109] When elemental sulfur is partially provided at room temperature, the mixture in step a) preferably contains up to 30% by weight, more preferably up to 10% by weight, of elemental sulfur based on the total weight of elemental sulfur.

[0110] When the cyclic monothiocarbonate compound of formula (I) is partially provided at room temperature, the mixture of step a) preferably contains up to 20% by weight, more preferably up to 5% by weight, of the total weight of the cyclic monothiocarbonate compound of formula (I) based on the total weight of the cyclic monothiocarbonate compound of formula (I).

[0111] The anionic polymerization initiator can be provided at room temperature or can be added at the copolymerization temperature before or simultaneously with the cyclic monothiocarbonate compound of formula (I).

[0112] If necessary, the organothiol compound is typically added to the method at room temperature or at the copolymerization temperature before or simultaneously with the cyclic monothiocarbonate compound of formula (I).

[0113] A cyclic monothiocarbonate compound of formula (I) is typically added to effectively suppress the homopolymerization of the resulting olefinic sulfur. This addition is usually slow, such as by dropwise addition or in small portions, so that it has only a low concentration in the reaction mixture. The addition rate should be appropriately adjusted to control the formation of foam.

[0114] The cyclic monothiocarbonate compound of formula (I) can be added as a solution in a solvent or preferably added without a solvent, if the cyclic monothiocarbonate compound is a liquid.

[0115] The product containing the sulfur copolymer, or a composition containing one or more sulfur copolymers, can be separated from the resulting reaction mixture in various ways. After cooling to room temperature, the product is typically separated from the reaction mixture to obtain the copolymer or a composition containing one or more copolymers for further processing in various applications. This type of separation step is usually carried out by conventional methods.

[0116] Depending on the molecular weight of the resulting sulfur copolymer and its solubility in organic solvents, the product can be separated from the reaction mixture by homogenization and / or filtration. Homogenization is preferably carried out using suitable organic solvents, such as halogenated solvents, N-methylpyrrolidone (NMP), tetrahydrofuran (THF), toluene, or carbon disulfide.

[0117] For example, the reaction mixture may optionally be filtered after homogenization. The product may be separated from the filtrate, for example, by evaporating the solvent and / or by washing with a suitable solvent and / or water and drying under reduced pressure. The product may be further purified by conventional means.

[0118] Examples of suitable copolymerization methods include the following process variations A)-H):

[0119] A) A method including the following steps:

[0120] a) Provide the anionic polymerization initiator and optionally a solvent and / or an organothiol compound;

[0121] b) Heat the product obtained in step a) to the desired copolymerization temperature;

[0122] c) Simultaneously or alternately adding a cyclic monothiocarbonate compound of formula (I) and elemental sulfur, while copolymerizing the cyclic monothiocarbonate compound of formula (I) and sulfur to form a reaction mixture containing the copolymer; and

[0123] d) Optionally, the copolymer can be separated from the reaction mixture.

[0124] B) A method including the following steps:

[0125] a) Provide the anionic polymerization initiator, elemental sulfur, and optionally a solvent and / or an organothiol compound;

[0126] b) Heat the product obtained in step a) to the desired copolymerization temperature;

[0127] c) Adding a cyclic monothiocarbonate compound of formula (I) while copolymerizing the cyclic monothiocarbonate compound of formula (I) with sulfur to form a reaction mixture comprising the copolymer; and

[0128] d) Optionally, the copolymer can be separated from the reaction mixture.

[0129] C) A method including the following steps:

[0130] a) Provide the anionic polymerization initiator, elemental sulfur, and optionally a solvent and / or an organothiol compound;

[0131] b) Heat the product obtained in step a) to the desired copolymerization temperature;

[0132] c) Simultaneously or alternately adding the cyclic monothiocarbonate compound of formula (I) and optionally further elemental sulfur, while copolymerizing the cyclic monothiocarbonate compound of formula (I) and sulfur to form a reaction mixture comprising the copolymer; and

[0133] d) Optionally, the copolymer can be separated from the reaction mixture.

[0134] D) A method including the following steps:

[0135] a) Provides the anionic polymerization initiator, a cyclic monothiocarbonate compound of formula (I), and optionally a solvent and / or an organothiol compound;

[0136] b) Heat the product obtained in step a) to the desired copolymerization temperature;

[0137] c) The remaining portion of the cyclic monothiocarbonate compound of formula (I) and elemental sulfur are added simultaneously or alternately, while the cyclic monothiocarbonate compound of formula (I) and sulfur are copolymerized to form a reaction mixture containing the copolymer; and

[0138] d) Optionally, the copolymer can be separated from the reaction mixture.

[0139] E) A method including the following steps:

[0140] a) Provide the anionic polymerization initiator and elemental sulfur, and optionally an organothiol compound;

[0141] b) Heat the product of step a) to a copolymerization temperature of at least 120°C;

[0142] c) Adding a cyclic monothiocarbonate compound of formula (I) while copolymerizing the cyclic monothiocarbonate compound of formula (I) with sulfur to form a reaction mixture comprising the copolymer; and

[0143] d) Optionally, the copolymer can be separated from the reaction mixture.

[0144] F) A method including the following steps:

[0145] a) Provide elemental sulfur and optionally solvents and / or organothiols;

[0146] b) Heat the product obtained in step a) to the desired copolymerization temperature;

[0147] c) Adding the cyclic monothiocarbonate compound of formula (I) and the anionic polymerization initiator, preferably simultaneously, to copolymerize the cyclic monothiocarbonate compound of formula (I) with sulfur to form a reaction mixture containing the copolymer; and

[0148] d) Optionally, the copolymer can be separated from the reaction mixture.

[0149] G) A method including the following steps:

[0150] a) Provide the anionic polymerization initiator and elemental sulfur, as well as an optional solvent;

[0151] b) Heat the product obtained in step a) to the desired copolymerization temperature;

[0152] c) Adding the cyclic monothiocarbonate compound of formula (I) and optionally the organothiol compound, preferably simultaneously, to copolymerize the cyclic monothiocarbonate compound of formula (I) with sulfur to form a reaction mixture comprising the copolymer; and

[0153] d) Optionally, the copolymer can be separated from the reaction mixture.

[0154] H) includes the following steps:

[0155] a) Provide the solvent;

[0156] b) Heat the solvent to a copolymerization temperature of 40-180°C;

[0157] c) Adding the cyclic monothiocarbonate compound of formula (I), elemental sulfur, the anionic polymerization initiator, and optionally the organothiol compound, preferably simultaneously, to copolymerize the cyclic monothiocarbonate compound of formula (I) with sulfur to form a reaction mixture comprising the copolymer; and

[0158] d) Optionally, the copolymer can be separated from the reaction mixture.

[0159] Preferred suitable examples of methods for performing this copolymerization are process variations A, B), C), and E).

[0160] Preferably, this method is carried out in the absence of solvents, typically under an inert atmosphere, such as nitrogen or argon. Sulfur can be used in its molten form at elevated temperatures, thus ≥120°C, and directly as the reaction medium.

[0161] This sulfur copolymer can be prepared by copolymerizing molten sulfur with at least one cyclic monothiocarbonate compound of formula (I). The temperature typically used in this solvent-free method is in the range of about 120-230°C. The reaction time for this copolymerization step can vary from 0.5 to 8 hours, preferably from 1 to 6 hours.

[0162] Therefore, the present invention relates, in a preferred aspect, to a method for preparing a sulfur copolymer, wherein the copolymerization step is carried out in the absence of a solvent, preferably at a temperature in the range of 120-230°C.

[0163] More preferably, a method for preparing a sulfur copolymer, wherein the method comprises the following steps:

[0164] a) Provide the anionic polymerization initiator and elemental sulfur;

[0165] b) Heat the mixture obtained in step a) to a temperature of 120-230°C;

[0166] c) Adding a cyclic monothiocarbonate compound of formula (I) and optionally further elemental sulfur, while copolymerizing the cyclic monothiocarbonate compound of formula (I) and sulfur to form a reaction mixture comprising the copolymer; and

[0167] d) Optionally, the copolymer can be separated from the reaction mixture.

[0168] Step d) is preferably performed by homogenization and filtering.

[0169] The cyclic monothiocarbonate compound of formula (I) and the optional addition of further elemental sulfur can be carried out simultaneously or alternately.

[0170] The process of step a) is preferably carried out in a temperature range of 120-230°C, more preferably 170-230°C, especially 170-190°C, 190-210°C or 210-230°C.

[0171] The copolymerization step is preferably carried out in a temperature range of 120-150℃, 150-170℃, 170-190℃, 190-210℃ or 210-230℃.

[0172] More preferably, the copolymerization step is carried out in a temperature range of 170-190°C, 190-210°C, or 210-230°C.

[0173] The reaction time for the copolymerization step is typically between 0.5 and 8 hours, preferably between 1 and 6 hours.

[0174] More preferably, the present invention relates to a method for preparing a sulfur copolymer, wherein the method comprises the following steps:

[0175] a) Provide the anionic polymerization initiator and elemental sulfur;

[0176] b) Heat the product obtained in step a) to a temperature range of 170-230°C;

[0177] c) Adding the cyclic monothiocarbonate compound of formula (I) and optionally further elemental sulfur to the mixture obtained in step a), while copolymerizing the cyclic monothiocarbonate compound of formula (I) and sulfur for 0.5-8 hours to form a reaction mixture containing the copolymer; and

[0178] d) Optionally, the copolymer can be separated from the reaction mixture.

[0179] The ratio of monomers used in the method of this invention is typically selected to provide the desired properties of the sulfur copolymer.

[0180] Elemental sulfur and the cyclic monothiocarbonate compound of formula (I) can be used in various molar ratios. For example, the molar ratio of the cyclic monothiocarbonate compound of formula (I) to elemental sulfur is 99:1 to 1:99, preferably 80:20 to 20:80.

[0181] Therefore, the present invention relates, in a preferred aspect, to a method for preparing a sulfur copolymer, wherein the step of copolymerizing the cyclic monothiocarbonate compound of formula (I) with elemental sulfur is carried out in a molar ratio range of 99:1 to 1:99.

[0182] In another aspect, the present invention relates to a sulfur copolymer that can be obtained by methods as defined in any aspect herein.

[0183] Therefore, the present invention relates to a sulfur copolymer that can be obtained by a method comprising making the following formula The step of copolymerizing cyclic monothiocarbonate compounds with elemental sulfur in the presence of a polymerization initiator, wherein R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

[0184] Since this method typically provides a mixture of one or more sulfur copolymers, the present invention further relates to a composition comprising one or more sulfur copolymers that can be obtained by such a method, the method comprising making... The step of copolymerizing cyclic monothiocarbonate compounds with elemental sulfur in the presence of a polymerization initiator, wherein R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

[0185] Polysulfide units derived from elemental sulfur can be adjacent to cyclic monothiocarbonate compounds derived from formula (I). The sulfur atom of the olefinic sulfur unit and / or the β-carbon atom of the adjacent olefinic sulfur unit of formula (VIa) or (VIb) are incorporated.

[0186] Therefore, this sulfur copolymer can be described as having the formula alkylene units and polysulfides (S) x The copolymer contains at least one SS bond, wherein x can be about 1-10, preferably 1-8.

[0187] Therefore, in a preferred aspect, the present invention relates to a sulfur copolymer having at least two formulas. alkylene unit and at least one polysulfide S x The copolymer contains at least one SS bond, wherein x is 1-10, preferably 1-8.

[0188] More preferably, the method of the present invention provides a sulfur copolymer comprising n alkylene units of formula (IV) and (n+1) polysulfide units, wherein the polysulfide units comprise a total of (2n+1) to (2n+9) sulfur atoms, particularly (2n+1) to (2n+8) sulfur atoms, particularly (2n+1) to (2n+7) sulfur atoms, wherein n≥1.

[0189] Therefore, in a more preferred aspect, the present invention relates to a sulfur copolymer that can be obtained by the method of the present invention, said copolymer comprising n formulas The alkylene unit and (n+1) polysulfide units, wherein the polysulfide units contain a total of (2n+1) to (2n+9) sulfur atoms, n≥1, and R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

[0190] The polysulfide unit contains a total of (2n+1) to (2n+8) sulfur atoms, especially (2n+1) to (2n+7) sulfur atoms.

[0191] In another aspect, the present invention relates to a sulfur copolymer comprising n molecules of the formula... The alkylene unit and (n+1) polysulfide units, wherein the polysulfide units contain a total of (2n+1) to (2n+9) sulfur atoms, especially (2n+1) to (2n+8) sulfur atoms, particularly (2n+1) to (2n+7) sulfur atoms, n≥1, and R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

[0192] In another aspect, the present invention relates to a composition comprising one or more sulfur copolymers, said copolymers comprising n molecules of the formula... The alkylene unit and (n+1) polysulfide units, wherein the polysulfide units contain a total of (2n+1) to (2n+9) sulfur atoms, especially (2n+1) to (2n+8) sulfur atoms, particularly (2n+1) to (2n+7) sulfur atoms, n≥1, and R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

[0193] The compositions of the present invention may additionally comprise a reaction product wherein only one polysulfide unit is incorporated between two end groups obtained from the cyclic monothiocarbonate compound of formula (I).

[0194] Therefore, compositions comprising one or more sulfur copolymers are preferred, wherein the composition comprises one or more of the following formulas: and / or The polysulfides, where x is 2-8 and represents the total number of sulfur atoms present in formulas (IIIa), (IIIb) and (IIIc).

[0195] The sulfur copolymer can typically have an average molecular weight of up to 20,000, preferably up to 10,000, and more preferably up to 5,000 g / mol. As used herein, the term "molecular weight" refers to the number-average molecular weight Mn, typically determined by gel permeation chromatography (GPC) with polystyrene as a standard.

[0196] Sulfur copolymers or polymer compositions containing one or more sulfur copolymers can be processed by conventional methods into the desired form suitable for the respective application. For example, the sulfur copolymer can be used in optical applications, sealant applications, sulfur immobilization in polymer matrices, in metalworking fluids, and / or as an active material in Li-S batteries.

[0197] Therefore, in another aspect, the present invention relates to an article formed from a sulfur copolymer as defined herein or a polymer composition comprising one or more sulfur copolymers as defined herein.

[0198] Furthermore, the present invention relates to the use of sulfur copolymers as defined herein or polymer compositions comprising one or more sulfur copolymers as defined herein in any aspect for optical applications, sealant applications, sulfur immobilization in polymer matrices, metalworking fluids and / or as active materials in Li-S batteries.

[0199] A new chemical platform for preparing sulfur-based polymer materials using cyclic monothiocarbonate compounds with attractive chemical accessibility and performance characteristics and elemental sulfur.

[0200] The method of the present invention allows for an readily available synthetic route for the preparation of organosulfur copolymers, which enables industrially feasible production and / or is economical and flexible.

[0201] Furthermore, the method of the present invention allows for the preparation of sulfur copolymers using S-containing monomers that have improved storage stability compared to ethylene sulfide or propylene sulfide.

[0202] The method of this invention can readily yield copolymers with the desired sulfur content, which can be adjusted to suit various applications. For example, the method can be adjusted to obtain sulfur copolymers suitable for forming sealants.

[0203] The method of the present invention particularly provides the availability of copolymers, for example, having a high sulfur content, suitable for use in the immobilization of sulfur in a polymer matrix, as a metalworking fluid, and / or as an active material in Li-S batteries.

[0204] For example, sulfur copolymers with high sulfur content and / or high viscosity can be appropriately used as metalworking fluids.

[0205] When this sulfur copolymer is to be used in optical elements, it may be desirable to use less sulfur in the process to provide optical clarity. Therefore, the sulfur copolymer of the present invention exhibits a high refractive index of, for example, about 1.65-2.1 at visible and infrared wavelengths and is therefore likely suitable for forming optical elements such as lenses, prisms and waveguides.

[0206] The definitions and preferred embodiments given for the foregoing methods may be applied in any combination and may be applied in any combination to other aspects of the invention.

[0207] The invention will now be explained in more detail with reference to the following embodiments. These embodiments should not be construed as limiting. Unless otherwise stated, "%" always refers to weight % (wt%). Example

[0208]

[0209] S8 (25.6 g, 0.1 mol) and Na2S (0.78 g, 0.01 mol) were added to a flask and heated to 180–190 °C under a nitrogen atmosphere, during which a viscous fluid formed with stirring. Me-CTC (23.6 g, 0.2 mol) was added dropwise over 30 minutes, simultaneously forming a reddish-brown mixture under volatile atmosphere. This mixture was stirred at 200 °C for 2 hours, during which a black viscous mixture formed. After cooling, a portion of this mixture was dissolved in chloroform, the solid residue was removed by filtration, and the solvent was evaporated under reduced pressure. A dark, viscous liquid was obtained.

[0210] The product was confirmed by HRMS-HPLC to be a composition comprising a propylene-sulfur copolymer of the following formula.

[0211]

[0212] M r = Relative molecular weight of a single isotope (dimensionless)

[0213] This empirical formula has been confirmed through precise quality analysis.

[0214] In a ethylene unit, two asterisks represent one hydrogen atom and one me atom.

[0215] Longer sulfur copolymers could not be obtained by HPLC analysis because they could not pass through the column non-destructively. The copolymers confirmed by HRMS each contained two oxygen atoms, with the presence of oxygen considered an artificial product of the analytical procedure.

[0216] HPLC-MS: Thermo Scientific Q Exactive Plus Orbitrap LC-MS / MS system (Column XSelect CSH C18, 150 × 3.0 mm, 3.5 μm; 1.0 ml / min, 40 °C; eluent THF)

[0217] Elemental analysis (Analyzer Vario Micro Cube / ELEMENTAR)

[0218] S: 77g / 100g

[0219] Elemental analysis revealed that the molar ratio of C:H:S was 3:6:5.1.

Claims

1. A method for preparing a sulfur copolymer, the method comprising, in the presence of a polymerization initiator, using the formula... (I) The step of copolymerizing cyclic monothiocarbonate compounds with elemental sulfur, wherein R 1 and R 2 They are independently hydrogen and C1-C 18 Alkyl groups, halogen-substituted or O- or S-spaced C1-C 18 Alkyl; C6-C 18 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

2. The method of claim 1, wherein R 1 and R 2 Independently, they are hydrogen, C1-C4 alkyl, halogenated, or C1-C separated by O or S. 18 Alkyl; C6-C 12 aryl or C6-C substituted with C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkylthio, or halogen 12 Aryl.

3. The method of claim 1, wherein R 1 It is hydrogen and R 2 It is hydrogen, C1-C4 alkyl, halogenated or C1-C8 alkyl or phenyl separated by O or S.

4. The method of claim 2, wherein R 1 It is hydrogen and R 2 It is hydrogen, C1-C4 alkyl, halogenated or C1-C8 alkyl or phenyl separated by O or S.

5. The method according to any one of claims 1-4, wherein R 1 It is hydrogen and R 2 It is hydrogen or C1-C4 alkyl.

6. The method according to any one of claims 1-4, wherein the polymerization initiator is an anionic polymerization initiator selected from metal salts, metal alkoxides, and basic inorganic salts containing amine bases, organophosphorus compounds, mercapto compounds, and thiol compounds.

7. The method of claim 6, wherein the anionic polymerization initiator is selected from basic inorganic salts.

8. The method according to any one of claims 1-4, wherein the copolymerization step is carried out at a temperature in the range of 40-230°C.

9. The method according to any one of claims 1-4, wherein the copolymerization step is carried out in the absence of a solvent.

10. The method of claim 9, wherein the copolymerization step is carried out at a temperature in the range of 120-230°C.

11. The method according to any one of claims 1-4, wherein the method comprises the following steps: a) Provide the anionic polymerization initiator and elemental sulfur; b) Heat the mixture obtained in step a) to a temperature of 120-230°C; c) Adding a cyclic monothiocarbonate compound of formula (I) and optionally further elemental sulfur, while copolymerizing the cyclic monothiocarbonate compound of formula (I) and sulfur to form a reaction mixture comprising the copolymer; and d) Optionally, the copolymer is separated from the reaction mixture.

12. The method according to any one of claims 1-4, wherein the step of copolymerizing the cyclic monothiocarbonate compound of formula (I) with elemental sulfur is carried out in a molar ratio range of 99:1 to 1:

99.

13. A sulfur copolymer obtained by the method defined in any one of claims 1-12.

14. The sulfur copolymer of claim 13, wherein the copolymer comprises n molecules of the formula... (II) an alkylene unit and (n+1) polysulfide units, wherein the polysulfide units comprise a total of (2n+1) to (2n+9) sulfur atoms, n≥1, and R 1 and R 2 As defined in any one of claims 1-5.

15. The sulfur copolymer of claim 14, wherein the polysulfide unit comprises a total of (2n+1) to (2n+8) sulfur atoms, and n≥1.

16. The sulfur copolymer of claim 14, wherein the polysulfide unit comprises a total of (2n+1) to (2n+7) sulfur atoms, and n≥1.

17. A formula containing n expressions (II) A sulfur copolymer of an alkylene unit and (n+1) polysulfide units, wherein the polysulfide units comprise a total of (2n+1) to (2n+9) sulfur atoms, n≥1, and R 1 and R 2 As defined in any one of claims 1-5.

18. A composition comprising one or more sulfur copolymers as defined in any one of claims 13 to 17.

19. The composition of claim 18, wherein the composition comprises one or more of the following formulas: (IIIa) (IIIb) and / or (IIIc) is a polysulfide compound, where x is 2-8 and represents the total number of sulfur atoms present in formulas (IIIa), (IIIb), and (IIIc), and R 1 and R 2 As defined in any one of claims 1-5.

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