Thionolactones, methods of synthesis, and uses as comonomers and for functionalizing and decomposing polymers - Patents.com

Abstract

The present invention relates to thionolactone compounds useful as comonomers to introduce weak bonds for the degradation or functionalization of polymers. The invention also relates to a process for the preparation of said compounds, in particular by sulfurization of the corresponding lactones. The invention further relates to the use of said thionolactones as comonomers, to copolymers made from these comonomers, and to a process for the preparation of said copolymers.

Description

[Technical field]

[0001] The present invention relates to thionolactone compounds useful as comonomers to introduce weak bonds for the degradation or functionalization of polymers. The invention also relates to a process for the preparation of said compounds, in particular by sulfurization of the corresponding lactones. The invention further relates to the use of said thionolactones as comonomers, to copolymers made from these comonomers, and to a process for the preparation of said copolymers.

[0002] Synthetic polymers are usually too large to be degraded as they are, so reducing their molecular weight is believed to make them more easily degradable. Reducing the molecular weight can be achieved by introducing weak bonds into the polymer backbone. These weak bonds can be introduced by copolymerizing regular monomers with compounds such as cyclic ketene acetals and thionolactones. Introducing weak bonds into synthetic polymers can be achieved by radical ring-opening polymerization of standard monomers with cyclic monomers. The Chemical Reviews Chem. Rev.2017,117,3,1319-1406 provides a list of many types of monomers that can be used in rROP.

[0003] Some thionolactones are known to be capable of being used in radical ring-opening polymerization (rROP). The most studied is dibenzo[c,e]oxepane-5-thione (DOT), which has been reported in Bingham, NM; Roth, PJ, Degradable vinyl copolymers through thiocarbonyl addition-ring-opening (TARO) polymerization. Chemical Communications 2019,55(1),55-58, Smith, RA; Fu, G.; McAteer, O.; Xu, M.; Gutekunst, WR, Radical Approach to Thioester-Containing Polymers. Journal of the American Chemical Society 2019,141(4),1446-1451, and Spick, MP; Bingham, NM; Li, Y.; de Jesus, J.; Costa, C.; Bailey, MJ; Roth, PJ, Fully Degradable Thioester-Functional Homo- and Alternating Copolymers Prepared through Thiocarbonyl Addition-Ring-Opening RAFT Radical Polymerization. Macromolecules 2020,53(2),539-547; and Bingham NM; un Nisa, Qamar; Chua, SHL, Fontugne, L., Spick, MP, Roth, PJ, Thioester-Functional Polyacrylamides: Rapid Selective Backbine Degradation Triggers Solubility Switch Based on Aqueous Lower Critical Solution Temperature / Upper Critical Solution Temperature. ACS Applied Polymer Materials 2020,2,3400-3449.

[0004] Existing thionolactones, particularly DOT, do not copolymerize readily with common comonomers and are not water soluble.

[0005] The present invention seeks to overcome these drawbacks. Summary of the Invention

[0006] Within the framework of intensive research, the inventors have found new compounds, in particular thionolactones, which due to their structure easily copolymerize and become more water-soluble.

[0007] The present invention therefore relates to these novel compounds, particularly thionolactones, their process for preparation, their copolymerization with conventional comonomers by radical processes, and the decomposition of the resulting copolymers under specific conditions. The novel compounds, particularly thionolactones, are also valuable as comonomers to introduce functionality and impart decomposition properties to the copolymers obtained therefrom, making them useful in a variety of applications.

[0008] In particular, the present invention also relates to the following:

[0009] Thionolactone of Formula I [ka] (In the formula, X is either a heteroatom selected from the group consisting of O and S, or NAlk, and Alk is a linear or branched alkyl group containing 1 to 6 carbons, preferably containing 1 to 4 carbons; R1, R2, R3, and R4, and R1', R2', R3', R4', and R 5’ are H, halogens, hydroxyl (-OH), thio (-SH), nitro (-NO2), amine (-NH2), ammonium (-NH4 + ), sulfate (-SO4 - ), sulfonates (-SO3 - ), phosphate (-PO4 2-), phosphonates (-PO3 2- ), and hydrocarbyls containing 1 to 50 carbon atoms (heteroatom means O, N, or S), which may be optionally substituted with one or more heteroatom-containing groups and / or may be interrupted by one or more heteroatoms or heteroatom-containing groups, and / or may optionally form a ring, which may be aromatic or non-aromatic.

[0010] A process for the preparation of a thionolactone of formula I as defined herein by reacting a compound of formula II with a sulfurizing agent. [ka] (wherein X, R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are as defined for formula I).

[0011] The use of a thionolactone of formula I as defined herein as a comonomer for preparing a copolymer.

[0012] Repeating Unit of Formula III [ka] (wherein X, R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are as defined for formula I). and at least one other type of repeat unit.

[0013] A process for the preparation of a copolymer as defined herein, wherein the thionolactone of formula I is copolymerized with at least one further comonomer selected from the group consisting of alkyl acrylates, N-alkylacrylamides, N,N-dialkylacrylamides, styrene and styrene derivatives, preferably 4-substituted styrene derivatives, acrylonitrile, and mixtures thereof, where "alkyl" means a linear or branched alkyl group containing 1 to 12, preferably 1 to 6 carbons, and the at least one further comonomer is preferably selected from N,N-dimethylacrylamide, styrene, and methyl acrylate.

[0014] The use of a thionolactone of formula I as defined herein as a comonomer to impart degradative properties to a copolymer prepared at least in part from the thionolactone of formula I as defined herein.

[0015] A process for the degradation of a copolymer as defined herein, comprising reacting said copolymer in an organic or aqueous medium with a degradation agent selected from the group consisting of bases, amines and oxidizing agents, preferably a base.

[0016] The use of a thionolactone of formula I as defined herein as a comonomer to introduce functional groups into a copolymer prepared in part from the thionolactone of formula I as defined herein.

[0017] A process for the functionalization of a copolymer as defined herein, comprising reacting said copolymer, in an organic or aqueous medium, with a decomposition agent selected from the group consisting of bases, amines and oxidizing agents, preferably a base.

[0018] Oligomers obtained by the process for degradation of the copolymers defined herein or by the process for functionalization of the copolymers defined herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Compounds of the Invention The present invention relates to thionolactone compounds of formula I [ka] Regarding.

[0020] In the compounds of formula I, the residues X, R1 to R4 and R'1 to R'5 have the following meanings:

[0021] X is either a heteroatom selected from the group consisting of O and S, or NAlk.

[0022] The abbreviation "Alk" in the group "NAlk" refers to a straight or branched alkyl group containing 1 to 6 carbons, preferably 1 to 4 carbons. Exemplary alkyl groups for use as "Alk" in the compounds of the invention include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, cyclopentyl, and n-hexyl, with methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl being preferred.

[0023] In a preferred embodiment of the compound of formula I, X is O.

[0024] R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are H, halogen, hydroxyl (-OH), thio (-SH), nitro group (-NO2), amine (-NH2), ammonium (-NH4 + ), sulfate (-SO4 - ), sulfonates (-SO3 - ), phosphate (-PO4 2- ), phosphonates (-PO3 2- ), and hydrocarbyl containing 1 to 50 carbon atoms).

[0025] The term "hydrocarbyl" as used herein refers to aryl groups, and straight-chain and branched aliphatic groups containing 1 to 50 carbon atoms, preferably 1 to 36 carbon atoms, more preferably 1 to 24 carbon atoms, even more preferably 1 to 12 carbon atoms, and most preferably 1 to 6 carbon atoms, which may optionally be substituted with one or more heteroatom-containing groups and / or may be interrupted by one or more heteroatoms or heteroatom-containing groups, and / or may optionally form an aromatic or non-aromatic ring.

[0026] Exemplary straight-chain and branched aliphatic groups useful as R1, R2, R3, and R4, as well as R1', R2', R3', R4', and R5', include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, and the like.

[0027] "Heteroatom" in the context of a hydrocarbyl group means O, N, or S. "Heteroatom-containing groups" in the context of a hydrocarbyl group include nitrogen-containing groups such as primary, secondary, and tertiary amines, oxygen-containing groups such as carboxy, hydroxy, and ether groups, and sulfur-containing groups such as thio and thioether groups.

[0028] The hydrocarbyl groups may optionally form a ring, which may or may not be aromatic (i.e., non-aromatic). The ring may be interrupted by one or more heteroatoms or heteroatom-containing groups as described above. In that case, the ring is a heterocycle, which may or may not be aromatic.

[0029] Examples of non-aromatic rings include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

[0030] An example of an aromatic ring is phenyl, which may optionally be further substituted with one or more functional groups such as: Hydrogen or C1-C1-C2-alkyl having 1 to 24 carbon atoms, optionally substituted with one or more heteroatoms or heteroatom-containing groups and / or optionally interrupted by one or more heteroatoms or heteroatom-containing groups 24 A linear or branched hydrocarbon group of ·halogen, hydroxy (-OH) or alkoxy (-OR) groups, where R is a linear or branched hydrocarbon group having 1 to 24 carbon atoms, optionally substituted and / or interrupted by one or more heteroatoms or heteroatom-containing groups, an amino group (-NRR'), where R and R' are independently hydrogen or a linear or branched hydrocarbon group having 1 to 24 carbon atoms, optionally substituted with one or more heteroatoms or heteroatom-containing groups and / or optionally interrupted by one or more heteroatoms or heteroatom-containing groups; acyl groups (-(C=O)-R), where R represents hydrogen or a C1-C6 alkyl group having 1 to 24 carbon atoms, optionally substituted with one or more heteroatoms or heteroatom-containing groups and / or optionally interrupted by one or more heteroatoms or heteroatom-containing groups; 24 represents a linear or branched hydrocarbon group; Carboxyl (-COOH) or alkoxycarbonyl (-(C=O)-OR) groups, where R is a C1-C alkyl group having 1 to 24 carbon atoms, optionally substituted with one or more heteroatoms or heteroatom-containing groups and / or optionally interrupted by one or more heteroatoms or heteroatom-containing groups. 24 represents a linear or branched hydrocarbon group; a carbamoyl group (-(C=O)-NRR'), where R and R' are independently hydrogen or a linear or branched hydrocarbon group having 1 to 24 carbon atoms, optionally substituted with and / or interrupted by one or more heteroatoms or heteroatom-containing groups, an alkylsulfonyl group (-SO2-R) or an alkylsulfinyl group (-SO-R) or an alkylthio group (-SR), where R is a C1-C1C alkyl group having 1 to 24 carbon atoms, optionally substituted with one or more heteroatoms or heteroatom-containing groups and / or optionally interrupted by one or more heteroatoms or heteroatom-containing groups; 24 represents a straight-chain or branched hydrocarbon group.

[0031] Examples of heteroaromatic rings include pyridyl, furanyl, pyrrolyl, thiophenyl, pyrazolyl, imidazolyl, benzimidazolyl, indolyl, quinolinyl, isoquinolinyl, purinyl, pyrimidinyl, thiazolyl, pyrazinyl, pyridazinyl, oxazolyl, and triazolyl, optionally further substituted with one or more functional groups as described above for phenyl.

[0032] Examples of non-aromatic heterocycles include pyrrolidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, piperidinyl, tetrahydropyranyl, tetrahydrothiopyranyl, hexamethyleneiminyl, hexamethyleneoxydyl, hexymethylenesulfidyl, optionally further substituted with one or more functional groups as described above for phenyl.

[0033] Preferably, R1, R2, R3, and R4, as well as R1', R2', R3', R4', and R5' in the compound of formula I are -H, -F, -Cl, -Br, hydroxyl (-OH), thio (-SH), nitro group (-NO2), amine (-NH2), ammonium (-NH4 + ), sulfate (-SO4 - ), sulfonates (-SO3 -and hydrocarbyls containing 1 to 50 carbon atoms, preferably 1 to 36 carbon atoms, more preferably 1 to 24 carbon atoms, even more preferably 1 to 12 carbon atoms, and even more preferably 1 to 6 carbon atoms, which may be substituted with one or more heteroatom-containing groups selected from -OY, -NHY, -NY2, -SY and / or may be interrupted by one or more heteroatoms or heteroatom-containing groups selected from -O-, -NY, -S-, wherein Y represents H or a branched or linear alkyl containing 1 to 12 carbon atoms, preferably a linear alkyl containing 1 to 6 carbon atoms.

[0034] In a preferred embodiment, R1, R2, R3, R4, R1', R2', R3', R4', or R5', preferably R3 or R3', is a group represented by, for example, the formula -(CH2-CH2-O) n represents a polyethylene glycol group of -H, where n is an integer varying from 1 to 25, preferably from 1 to 18, more preferably from 1 to 12. This embodiment is preferably combined with the embodiment where X=O.

[0035] In a further preferred embodiment, in the compound of formula I, at least R1, R1', and R5' are H. This embodiment is preferably combined with the embodiment where X=O.

[0036] More preferably, in the compound of formula I, at least R1, R4, R1', and R5' are H. This embodiment is preferably combined with the embodiment where X=O.

[0037] More preferably, in the compound of formula I, at least R1, R3, R4, R1', R3', and R5', or at least R1, R2, R4, R1', R2', R4', and R5' are H. This embodiment is preferably combined with the embodiment where X=O.

[0038] Particularly preferably, in compounds of formula I, R1, R2, R3 and R4, as well as R1', R2', R3', R4' and R5' are H. This embodiment is preferably combined with the embodiment in which X=O.

[0039] In a highly preferred embodiment, in the compound of formula I, R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are H and X is O. The compound is 2-phenyl-4H-benzo[d][1,3]dioxine-4-thione.

[0040] The thionolactone compounds of formula I are suitable for use as comonomers to obtain copolymers that contain weak thioester bonds derived from the thionolactone moiety of the compounds of formula I, making the resulting copolymers useful for degradation and functionalization purposes.

[0041] Methods for preparing compounds of formula I The present invention further relates to a method for preparing a thionolactone of formula I, which is a sulfurization reaction, [ka] reacts with the sulfurizing agent.

[0042] In the compound of formula II, X, R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are defined as detailed herein above for the compound of formula I.

[0043] The sulfurizing agents used in the process of the present invention for preparing the compounds of formula I are typically Lawesson's reagent (2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiadiphosphetane 2,4-disulfide), Davy's reagent (2,4-bis(methylthio)-2,4-dithioxo-1,3,2,4-dithiadiadiphosphetane, (CHS)PS)), Curphey's reagent (hexamethyldisiloxane (HMDO) / phosphorus pentasulfide (PSO)), 10), Kaushik's reagent (P4S 10 / Al2O3), Bernthsen's reagent (S8 / I2), Heimgartner's reagent (2,4-bis(4-methylphenylthio)-1,3,2λ5,4λ5-dithiadiphosphetane-2,4-dithione), Jan Bergman's reagent (see http: / / vironovamedical.com / wp-content / uploads / 2019 / 04 / Vironova-Medical-Thionation-181029.pdf), Belleau's reagent (2,4-bis(4-phenoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide), Japanese's reagent (2,4-bis(phenylthio)-1,3,2,4 -dithiadiadiphosphetane 2,4-disulfide), H2S, CS2, R2PSX, (Et2Al)2S, NaSH, TMS2S, thiourea / Ru(III) / Al2O3, benzyltriethylammonium tetrathiomolybdate, thioacyl-N-pthalimide, elemental sulfur, aqueous ammonium sulfide, SiS2, hexamethyldisilathiane (HMDST), PSCl3 / H2O / Et3N, polymer supported sulfurizing agents and in situ sulfurizing agents such as P2S5 / Na2CO3.

[0044] A preferred sulfurizing agent for use in the present process for preparing compounds of formula I is Lawesson's reagent.

[0045] The process of the invention for the preparation of a compound of formula I is typically carried out in an organic solvent, which is preferably a non-polar organic solvent selected from the group consisting of toluene, n-hexane, benzene, pentane, chloroform, diethyl ether, 1,4-dioxane, carbon tetrachloride, and methylene chloride (dichloromethane).

[0046] In this case, the reaction is carried out at a temperature below the solvent reflux temperature at atmospheric pressure, preferably at a temperature in the range from ambient temperature (20-30°C) to the solvent reflux temperature, preferably at a temperature in the range from 50°C to the solvent reflux temperature at atmospheric pressure.

[0047] In a highly preferred embodiment, the synthesis of 2-phenyl-4H-benzo[d][1,3]dioxine-4-thione involves first reacting benzaldehyde (2) with sulfuric acid to produce diacetate (3), which is then condensed with salicylic acid (1) under acidic conditions to produce compound (4), which corresponds to the compound of formula II, where R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are H and X is O. The corresponding thionolactone (5) (2-phenyl-4H-benzo[d][1,3]dioxine-4-thione, i.e., the compound of formula I, where R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are H and X is O) is obtained by reacting the compound of formula (4) with Lawesson's reagent. An exemplary synthetic route of this highly preferred embodiment is depicted below in Scheme 1, which reflects the procedure applied to synthesize 2-phenyl-4H-benzo[d][1,3]dioxine-4-thione in Example 1. [ka]

[0048] Use of compounds of formula I as comonomers The present invention further relates to the use of thionolactones of formula I as comonomers to prepare copolymers, including the copolymers of the present invention described below.

[0049] Copolymers of the Invention The present invention further relates to a repeat unit of formula III [ka] and at least one other type of repeat unit.

[0050] In the compound of formula III, X, R1, R2, R3, and R4, and R1', R2', R3', R4', and R5' are defined as described herein above for the compound of formula I.

[0051] Typically, at least one further repeat unit of the copolymers of the invention will be derived from a comonomer that is "more activated," in the sense that it is useful as a comonomer in radical copolymerization reactions with the compounds of formula I.

[0052] In particular, at least one further repeat unit is derived from a comonomer selected from the group consisting of alkyl acrylates, N-alkylacrylamides, N,N-dialkylacrylamides, styrene and styrene derivatives, and acrylonitrile, or mixtures thereof.

[0053] "Alkyl" in the context of these comonomers means a linear or branched alkyl group containing 1 to 12 carbons. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, n-nonyl, n-decyl, n-undecanyl, and n-dodecyl. Preferably, the linear or branched alkyl group contains 1 to 6 carbons, more preferably 1 to 4 carbons, i.e., methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl, with methyl being especially preferred.

[0054] Thus, examples of alkyl acrylates useful as comonomers to provide the copolymers of the present invention include, but are not limited to, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and tert-butyl acrylate.

[0055] Thus, examples of N-alkylacrylamides useful as comonomers to provide the copolymers of the present invention include, but are not limited to, N-methylacrylamide, N-ethylacrylamide, Nn-propylacrylamide, N-isopropylacrylamide, Nn-butylacrylamide, N-isobutylacrylamide, N-tert-butylacrylamide.

[0056] Thus, examples of N,N-dialkylacrylamides useful as comonomers to provide the copolymers of the present invention include, but are not limited to, N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-di-n-propylacrylamide, N,N-diisopropylacrylamide, N,N-di-n-butylacrylamide, N,N-diisobutylacrylamide, N,N-di-tert-butylacrylamide.

[0057] As used herein, "styrene derivative" refers to styrene in which the benzene moiety is substituted with one or more functional groups. The preferred styrene derivative for providing the copolymer of the present invention is a styrene derivative in which the 4-position of the benzene moiety is substituted with a functional group (i.e., a 4-substituted styrene derivative). Functional groups used in substituted styrene derivatives include, but are not limited to, the following: · linear and branched alkyl containing 1 to 4 carbons, i.e. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl; · Alkoxy containing 1 to 4 carbons, i.e. methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy, isobutyloxy, tert-butyloxy (e.g. 4-methoxystyrene); Phenoxy and phenoxy substituted with one or more functional groups; ·Halogens including F, Cl, Br, I; · Perfluoroalkyl, including for example CF3; · Sulfonates (e.g. sodium-4-vinylbenzenesulfonate).

[0058] Preferably, at least one further repeat unit is of the following formulae IV, V, VI and mixtures thereof: [ka] which are derived from N,N-dimethylacrylamide (Formula IV), styrene (Formula V), and methyl acrylate (Formula VI).

[0059] Comonomers such as vinyl acetate and its ester derivatives, carbazole, N-vinylpyrrolidone, ethylene, allyl, etc. are "low activity" and therefore not suitable for use as comonomers to provide the copolymers of the present invention. A similar assessment applies to methacrylic acid esters and methacrylamides, the methyl group providing a stabilizing effect during radical polymerization and preventing copolymerization with the compounds of formula I.

[0060] The repeat unit of formula III, and in particular the thioester bond that forms part of repeat unit III, introduces a weak link into the copolymer, making it suitable for degradation and functionalization.

[0061] Methods for preparing the copolymers of the present invention The present invention further relates to a method for preparing the copolymers of the present invention as described above, in which the thionolactone of formula I as described herein is copolymerized with at least one other comonomer as described hereinabove in connection with the copolymers of the present invention. From a mechanistic point of view, the copolymerization process of the present invention is a radical ring-opening copolymerization process that introduces a thioester bond as reflected in formula III into the polymer backbone.

[0062] According to the above description of the copolymer of the present invention, the comonomer used in the copolymerization process of the present invention is selected from the group consisting of alkyl acrylates, N-alkylacrylamides, N,N-dialkylacrylamides, styrene and styrene derivatives, and acrylonitrile, or mixtures thereof. The exemplary and preferred embodiments of the comonomers mentioned above in relation to the copolymer of the present invention also apply to the method for preparing the copolymer of the present invention. Thus, N,N-dimethylacrylamide, styrene, methyl acrylate, and mixtures thereof are preferred comonomers for use in the method for preparing the copolymer of the present invention.

[0063] Comonomers such as vinyl acetate and its ester derivatives, carbazole, N-vinylpyrrolidone, ethylene, allyl, etc. are "low activity" and therefore not suitable for use as comonomers in the process for preparing the copolymers of the present invention. A similar assessment applies to methacrylic acid esters and methacrylamides, the methyl group of which provides a stabilizing effect during radical polymerization, preventing copolymerization with the compound of formula I.

[0064] The copolymerization process of the present invention is typically carried out in the presence of a radical initiator. In the preparation method of the copolymer of the present invention, various well-known radical initiators can be used, such as azo compounds such as azobisisobutyronitrile (AIBN) and 1,1'-azobis(cyclohexanecarbonitrile) (ABCN); organic peroxides such as dibenzoyl peroxide (DBPO), di-tert-butyl peroxide, and methyl ethyl ketone peroxide; inorganic peroxides including peroxydisulfates such as Na2S2O8, K2S2O8, and (NH4)2S2O8. However, typically and preferably, the well-known azobisisobutyronitrile (AIBN) is used herein.

[0065] The copolymerization process of the present invention can be carried out as a bulk polymerization (ie, in the absence of a solvent).

[0066] Alternatively, the copolymerization process of the present invention can be carried out in an organic solvent, which is typically a non-polar solvent, such as a hydrocarbon solvent, e.g., pentane, hexane, benzene, toluene, and ether solvents, e.g., 1,4-dioxane, diethyl ether, tetrahydrofuran (THF), anisole; or a polar aprotic solvent, e.g., dichloromethane (DCM), chloroform, ethyl acetate, acetone, dimethylformamide (DMF), dimethylsulfoxide (DMSO); anisole is one preferred organic solvent for use in the copolymerization process of the present invention.

[0067] Alternatively, the copolymerization process of the present invention can be carried out in a water-alcoholic solvent mixture, which comprises at least one alcohol and water, the alcohol being selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, and mixtures thereof. Preferably, an ethanol / water mixture is used as the water-alcoholic mixture in the copolymerization process of the present invention.

[0068] The ratio of at least one alcohol to water (i.e. alcohol component:water) in the aqueous alcohol solvent mixture is in the range of 50:50 to 99:1 vol / vol, preferably 60:40 to 95:5 vol / vol, more preferably 70:30 to 90:10 vol / vol, particularly preferably 80:20 vol / vol. Thus, for example, when an ethanol / water mixture is used as the aqueous alcohol solvent mixture, the ratio of ethanol to water in said mixture is particularly preferably 80:20 vol / vol.

[0069] Whether the copolymerization process of the present invention is carried out in an organic solvent mixture or a water-alcoholic solvent mixture can be determined based, for example, on the solubility of thionolactone in the respective solvent mixture.

[0070] The amount of comonomer used in the copolymerization process of the present invention typically ranges from 1 to 10 molar equivalents based on the molar amount of the compound of formula I used. Preferably, the amount of comonomer ranges from 1.5 to 15 equivalents, more preferably 2 to 12 molar equivalents, and even more preferably 3 to 9 molar equivalents based on the molar amount of the compound of formula I used. The higher the relative molar amount of thionolactone in the mixture of thionolactone and comonomer, the greater the percentage of thioester linkages formed during copolymerization.

[0071] The amount of catalyst used in the copolymerization process of the present invention is typically in the range of 0.1 mol % to 15 mol %, preferably 0.2 mol % to 10 mol %, more preferably 0.5 mol % to 5 mol %, for example 1 mol %, 2 mol %, 3 mol %, and 4 mol %, based on the molar amount of the compound of formula I used in the copolymerization reaction.

[0072] The copolymerization process of the present invention is typically carried out at a temperature ranging from ambient temperature to 120°C, preferably from 40°C to 110°C, more preferably from 60°C to 100°C, more preferably from 70°C to 90°C, for example at 80°C.

[0073] Use of a compound of formula I as a comonomer to impart degradable properties to a copolymer made in part from the compound of formula I The present invention further relates to the use of thionolactone of formula I as described herein as a comonomer to impart degradative properties to a copolymer prepared in part from the thionolactone of formula I as described herein, the copolymer prepared in part therefrom preferably being a copolymer of the invention as described herein above.

[0074] Decomposition process of copolymers The present invention further relates to a process for the degradation of the copolymers of the present invention as described above, which is carried out by reacting said copolymers in an organic or aqueous medium with a decomposition agent selected from the group consisting of bases, amines and oxidizing agents, preferably a base.

[0075] Thus, depending on the decomposition reagent, the degradation process of the present invention can be carried out as hydrolysis (using a base as the decomposition reagent), aminolysis (using an amine as the decomposition reagent), or oxidative hydrolysis (using an oxidizing agent as the decomposition reagent). Decomposition of the copolymers of the present invention by the methods described herein results in the formation of smaller oligomers.

[0076] The decomposition process of the present invention can be carried out in an organic medium, including an organic solvent or a mixture of organic solvents. Organic solvents suitable for use in the decomposition process of the present invention include common organic solvents, such as alcohols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, ethers, such as diethyl ether, methyl-tert-butyl ether, tetrahydrofuran (THF), chlorinated solvents, such as dichloromethane (DCM) and chloroform, dimethylformamide (DMF), dimethylsulfoxide (DMSO), ethyl acetate, acetone, and mixtures thereof.

[0077] Alternatively, the degradation process of the present invention can be carried out in an aqueous medium, which may optionally further comprise an organic solvent or a mixture of organic solvents, preferably an alcohol selected from the group of methanol, ethanol, n-propanol, isopropanol, n-butanol and mixtures thereof, with ethanol being particularly preferred. In such hydroalcoholic media (i.e. a mixture of at least one alcohol with water), the amount of alcohol in the hydroalcoholic medium is typically at least 60% by weight, preferably at least 70% by weight, more preferably at least 80% by weight.

[0078] To carry out the degradation process of the present invention, it is possible to add the copolymer to a decomposition reagent (contained in, preferably dissolved in, an organic or aqueous medium), which is typically carried out by adding the decomposition reagent to an organic or aqueous medium containing the copolymer. In this case, the concentration of the copolymer in the medium is typically in the range of 0.01 g / mL to 0.5 g / mL. The decomposition reagent can be added neat or as an organic or aqueous solution.

[0079] In the aminolysis process of the present invention, amines such as ammonia, isopropylamine, or dimethylamine can be used as decomposition reagents. The process is then preferably carried out in an organic medium, such as, for example, methanol, tetrahydrofuran (THF), or dichloromethane (DCM). Those skilled in the art can select the amount of amine used in the decomposition process for the copolymer as required, taking into account common technical knowledge. The reaction mixture is typically stirred at ambient temperature for 3 to 24 hours, preferably 6 to 18 hours, and more preferably 12 to 15 hours.

[0080] In the oxidative hydrolysis process of the present invention, an oxidizing agent such as oxone (KHSO5·1 / 2KHSO4·1 / 2K2SO4) can be used as a decomposition reagent. In this case, the process is preferably carried out in an aqueous medium. Those skilled in the art can select the amount of oxidizing agent used in the decomposition process for the copolymer as required, taking into account common technical knowledge. The reaction mixture is typically stirred at ambient temperature for 3 to 24 hours, preferably 6 to 18 hours, more preferably 12 to 15 hours.

[0081] In the hydrolysis process of the present invention preferably used herein, common bases such as potassium hydroxide (KOH), sodium hydroxide (NaOH), lithium hydroxide (LiOH), ammonium hydroxide (NHOH), calcium hydroxide (Ca(OH)2), magnesium hydroxide (Mg(OH)2), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3), sodium dihydrogen phosphate (NaH2PO4), potassium dihydrogen phosphate (KH2PO4) can be used, with potassium hydroxide and sodium hydroxide being preferred.

[0082] The base is typically added to the medium containing the copolymer in an aqueous, hydroalcoholic or alcoholic solution. The concentration of the base in the solution is typically in the range of 1% to 20% by weight, preferably 2% to 10% by weight, for example 5% by weight. Those skilled in the art can select the amount of base used in the degradation process for the copolymer as required, taking into account common technical knowledge. The resulting mixture is typically stirred at ambient temperature for 3 to 24 hours, preferably 6 to 18 hours, more preferably 12 to 15 hours.

[0083] A preferred organic medium for use in the hydrolysis process using a base as the decomposition agent is THF or a mixture of THF and methanol, in which the ratio of THF:methanol is typically at least 60:40 vol / vol, preferably at least 70:30 vol / vol, more preferably at least 80:20 vol / vol, for example 90:10 vol / vol.

[0084] The hydrolysis process of the present invention is carried out, for example, by dissolving the copolymer in tetrahydrofuran (THF) and adding a base, for example a solution of KOH in methanol, to the copolymer solution.

[0085] A preferred hydroalcoholic medium for use in a hydrolysis process using a base as the decomposition agent is a mixture of ethanol and water, the ethanol:water ratio typically being at least 60:40 wt / wt, preferably at least 70:30 wt / wt, more preferably at least 80:20 wt / wt, such as 80:20 wt / wt, 90:10 wt / wt, and 95:5 wt / wt.

[0086] The hydrolysis process of the present invention is then carried out, for example, by dissolving the copolymer in an ethanol / water mixture (eg, 80:20 wt / wt) and adding a base, for example a solution of KOH in methanol, to the aqueous copolymer solution.

[0087] Use of a compound of formula I as a comonomer to introduce functional groups into a copolymer prepared in part from the compound of formula I The present invention further relates to the use of the thionolactone of formula I as a comonomer for introducing functional groups into a copolymer prepared in part therefrom. The copolymer prepared in part therefrom is preferably a copolymer of the invention as described herein above.

[0088] The introduction of functionality in the form of a thioester bond into the copolymers produced in part from the compounds of formula I used as comonomers renders the copolymers suitable for functionalization, for example when treated with a decomposition agent selected from the group consisting of bases, amines, and oxidizing agents mentioned above, and the smaller oligomers obtained from such treatment are functionalized at each end of the oligomer with -SH and -COOH, upon cleavage of the thioester.

[0089] Copolymer Functionalization Process The present invention further relates to a process for the functionalization of the copolymers of the invention described above, which is carried out by reacting said copolymers, in an organic or aqueous medium, with a decomposition agent selected from the group consisting of bases, amines and oxidizing agents, preferably a base.

[0090] The process details for the functionalization process of the present invention are the same as those described above for the decomposition process of the present invention.

[0091] The functionalization process of the present invention results in smaller oligomers resulting from such treatment having each end of the oligomer functionalized with -SH and -COOH upon cleavage of the thioester.

[0092] Oligomers The invention further relates to oligomers obtainable by the degradation process of the copolymers described above or by the functionalization process of the copolymers described above.

[0093] The following examples are intended to illustrate the invention without limiting its scope. EXAMPLES

[0094] Example 1: Synthesis of thionolactone 2-phenyl-4H-benzo[d][1,3]dioxine-4-thione (Formula I). 1.1 Synthesis of phenylmethylene diacetate To a solution of benzaldehyde (10.6 g) in acetic anhydride (100 mL) was added dropwise a solution of H2SO4 (160 mg) in acetic anhydride (20 mL). Stirring was then continued for 1 h, after which the mixture was poured into an ice-H2O mixture. The mixture was extracted with EtOAc (3 x 100 mL), and the combined organic phases were then washed with H2O (x2) and saturated NaHCO3. The solvent was removed by rotary evaporation (60 °C). Residual acetic anhydride was then removed under high vacuum at 55 °C to give phenylmethylene diacetate (17.4 g, 84%) as a colorless solid. 1 H NMR(CDCl3,400MHz):δ 2.12(s,6H),7.38-7.43(m,3H),7.49-7.54(m,2H),7.68(s,1H). 13C NMR:(CDCl3,100MHz):δ 20.5,89.4,126.4,128.3,129.4,135.3,168.4.

[0095] 1.2 Synthesis of 2-phenyl-4H-benzo[d][1,3]dioxin-4-one (formula II) A mixture of salicylic acid (4.8 g), phenylmethylene diacetate (7.25 g) obtained as above, acetic acid (3 mL), and H2SO4 (0.01 mL) was placed in a distillation apparatus and then heated to 70 °C under 27 mbar. After distillation of acetic acid stopped, the temperature was slowly increased to 110 °C over 2 h. The reaction was then cooled, followed by taking up the residual solid in Et2O and washing with saturated NaHCO3 and saturated NaHSO3. The solvent was then removed by rotary evaporation to give 2-phenyl-4H-benzo[d][1,3]dioxin-4-one (6.3 g, 80%) as a tan solid. 1 H NMR(CDCl3,400MHz):δ 6.53(s,1H),7.07-7.14(m,1H),7.17-7.25(m,1H),7.43-7.51(m,3H),7.55-7.69(m,3H),8.01-8.06(m,1H). 13 C NMR:(CDCl3,100MHz):δ 100.5,114.6,116.9,123.6,126.6,128.7,130.3,130.4,134.1,136.5,158.2,161.9.

[0096] 1.3 Synthesis of 2-phenyl-4H-benzo[d][1,3]dioxine-4-thione (Formula I) A solution of 2-phenyl-4H-benzo[d][1,3]dioxin-4-one (8 g) obtained as described above and Lawesson's reagent (5.7 g, 0.4 equiv.) in toluene (400 mL) was refluxed for 24 h. The reaction was then cooled and passed through a silica plug using excess toluene. The solvent was then removed by rotary evaporation and the residue was purified by flash column chromatography (20% EtOAc in pentane). The residue was then recrystallized from DCM / pentane to give 2-phenyl-4H-benzo[d][1,3]dioxin-4-thione (3.6 g, 42% yield) as an orange solid. 1 H NMR(CDCl3,400MHz):δ 6.44(s,1H),7.05-7.20(m,2H),7.46-7.52(m,3H),7.55-7.63(m,1H),7.66-7.73(m,2H),8.29-8.36(m,1H). 13 C NMR:(CDCl3,100MHz):δ 101.0,117.0,123.1,123.8,126.9,128.7,130.6,133.0,133.6,136.2,153.3,202.7.

[0097] Example 2: Copolymerization of 2-phenyl-4H-benzo[d][1,3]dioxine-4-thione (Formula I) with different comonomers 2.1 Copolymerization in bulk 2.1.1 Dimethylacrylamide 21A - 10mol% thionolactone (for a mixture of thionolactone and N,N-dimethylacrylamide) 2-Phenyl-4H-benzo[d][1,3]dioxine-4-thione (100 mg), N,N-dimethylacrylamide (368 mg, 9 equiv.), and AIBN (6.8 mg, 1 mol%) obtained as described above were placed in a headspace vial equipped with a magnetic stir bar. The vial was then sealed and degassed using argon for 30 min. The vial was then submerged in a preheated oil bath held at 80° C. After 24 h, the solid was taken up in CHCl3 (3 mL) and then precipitated in pentane (50 mL) followed by centrifugation. The isolated solid was then dried under high vacuum at room temperature. 1 H NMR (CDCl3, 400MHz): 16.2% thioester bond

[0098] 2.1.2 Styrene 21B - 10 mol% thionolactone (for a mixture of thionolactone and styrene) 2-Phenyl-4H-benzo[d][1,3]dioxine-4-thione (100 mg), styrene (387 mg, 9 equiv.), AIBN (6.8 mg, 1 mol%), and anisole (3 mL) were placed in a headspace vial equipped with a magnetic stir bar. The vial was then sealed and degassed for 30 min using argon. The vial was then submerged in a preheated oil bath held at 80° C. After 72 h, the mixture was precipitated in Et2O (50 mL) and subsequently centrifuged. The isolated solid was then dried under high vacuum at room temperature. 1 H NMR (CDCl3, 400MHz): 10.4% thioester bond GPC (THF, calibrated with PS standard): Mn=12700, PDI=2.4

[0099] 2.1.3 Methyl acrylate 21C - 10mol% thionolactone (for a mixture of thionolactone and methyl acrylate) 2-Phenyl-4H-benzo[d][1,3]dioxine-4-thione (100 mg), obtained as described above, methyl acrylate (320 mg, 9 equiv.), AIBN (6.8 mg, 1 mol %), and anisole (3 mL) were placed in a headspace vial equipped with a magnetic stir bar. The vial was then sealed and degassed using argon for 30 min. The vial was then submerged in a preheated oil bath held at 80° C. After 72 h, the mixture was precipitated in pentane (50 mL) followed by centrifugation. The isolated solid was then dried under high vacuum at room temperature. 1 H NMR (CDCl3, 400MHz): 16.9% thioester bond

[0100] In bulk copolymerizations, the thioester bonds are higher than theoretical (meaning the calculated value based on the initial ratio of thionolactone to comonomer), except when bulk copolymerization is performed with styrene.

[0101] 2.2 Copolymerization with DMAA in organic solvents 22A - 8.7 mol% thionolactone (for a mixture of thionolactone and N,N-dimethylacrylamide) 2-Phenyl-4H-benzo[d][1,3]dioxine-4-thione (200 mg), N,N-dimethylacrylamide (858 mg, 10.48 equiv.), AIBN (47 mg, 3 mol%), and anisole (5 mL) were placed in a headspace vial equipped with a magnetic stir bar. The vial was then sealed and degassed using argon for 30 min. The vial was then submerged in a preheated oil bath held at 80 °C. After 20 h, the mixture was precipitated in Et2O (100 mL) and subsequently centrifuged. The isolated solid was then dried under high vacuum at room temperature. 1 H NMR (CDCl3, 400MHz): 7.5% thioester bond GPC (THF, calibrated with PS standard): Mn=5300, PDI=1.8

[0102] 22B - 10mol% thionolactone (for a mixture of thionolactone and N,N-dimethylacrylamide) 2-Phenyl-4H-benzo[d][1,3]dioxine-4-thione (100 mg), N,N-dimethylacrylamide (368 mg, 9 equiv.), AIBN (6.8 mg, 1 mol%), and anisole (2.5 mL) were placed in a headspace vial equipped with a magnetic stir bar. The vial was then sealed and degassed using argon for 30 min. The vial was then submerged in a preheated oil bath held at 80° C. After 3 h, the mixture was precipitated in pentane (50 mL) followed by centrifugation. The isolated solid was then dried under high vacuum at room temperature. 1 H NMR (CDCl3, 400MHz): 8.7% thioester bond GPC (THF, calibrated with PS standard): Mn=7200, PDI=2.1

[0103] 22C - 25mol% thionolactone (for a mixture of thionolactone and N,N-dimethylacrylamide) 2-Phenyl-4H-benzo[d][1,3]dioxine-4-thione (300 mg), N,N-dimethylacrylamide (368 mg, 3 equiv.), AIBN (24 mg, 3 mol%), and anisole (4 mL) were placed in a headspace vial equipped with a magnetic stir bar. The vial was then sealed and degassed using argon for 30 min. The vial was then submerged in a preheated oil bath held at 80 °C. After 24 h, the mixture was precipitated in Et2O (100 mL) and subsequently centrifuged. The isolated solid was then dried under high vacuum at room temperature. 1 H NMR (CDCl3, 400MHz): 22% thioester bond GPC (THF, calibrated with PS standard): Mn=6400, PDI=1.7

[0104] Conclusions regarding the effect of the molar ratio of thionolactone to copolymer in solvent polymerization: A good correlation could be observed between the thioester bonds in the copolymer and the initial amount of thionolactone in the mixture with the comonomer, suggesting that the comonomer reacts at the same rate.

[0105] 2.3 Copolymerization with DMAA in water and water / ethanol mixtures 23A - 10mol% thionolactone (for a mixture of thionolactone and N,N-dimethylacrylamide) 2-Phenyl-4H-benzo[d][1,3]dioxine-4-thione (150 mg), obtained as described above, N,N-dimethylacrylamide (552 mg, 9 equiv.), AIBN (5.1 mg, 0.5 mol%), and an 80 / 20 vol / vol mixture of ethanol / HO (1053 mg) (to obtain approximately 40 wt. % solids) were placed in a headspace vial equipped with a magnetic stir bar. The vial was then sealed and degassed using argon for 30 min. The vial was then submerged in a preheated oil bath held at 80 °C. After 20 h, the mixture was precipitated in pentane (50 mL) followed by centrifugation. The isolated solid was then dried under high vacuum at room temperature. 1 H NMR (CDCl3, 400MHz): 12% thioester bond GPC (THF, PS standard): Mn=5500, PDI=1.9

[0106] Example 3: Degradation of the copolymer under basic conditions 3.1 Decomposition of copolymers prepared in organic solvents A sample of copolymer 22A (200 mg) was dissolved in THF (9 mL) and 5 wt % KOH in MeOH (1 mL) and stirred overnight, then the solvent was removed by rotary evaporation. GPC (THF, PS standard): Mn=900, PDI=2.5

[0107] A sample of copolymer 22B (150 mg) was dissolved in THF (9 mL) and 5 wt % KOH in MeOH (1 mL) and stirred overnight, then the solvent was removed by rotary evaporation. GPC (THF, PS standard): Mn=700, PDI=2.6

[0108] A sample of copolymer 22C (150 mg) was dissolved in THF (9 mL) and 5 wt % KOH in MeOH (1 mL) and stirred overnight, then the solvent was removed by rotary evaporation. GPC (THF, PS standard): Mn=300, PDI=3.2

[0109] The molecular weight of PDMA (poly-N,N-dimethylacrylamide) obtained by decomposition of the copolymer formed in organic solvent increases linearly with the amount of thioester bonds and agrees quite well with the predicted theoretical mass.

[0110] 3.2 Decomposition of copolymers prepared in ethanol / water mixtures A sample of copolymer 23A (100 mg) was dissolved in 9 mL of an ethanol / water mixture (80 / 20 wt / wt) and 1 mL of 5 wt% KOH in MeOH and stirred overnight, then the solvent was removed by rotary evaporation. GPC (THF, PS standard): Mn=400, PDI=2.6

Claims

1. The thionolactone of formula I 【Chemical 1】 wherein X is a heteroatom selected from the group consisting of O and S, or NAlk, where Alk is a linear or branched alkyl group containing 1 to 6 carbons, preferably 1 to 4 carbons, R １ , R ２ , R ３ , and R ４ , and R １ ', R ２ ', R ３ ', R ４ ', and R ５ ' is H, halogen, hydroxyl (-OH), thio (-SH), nitro group (-NO ２ ), amine (-NH ２ ), ammonium (-NH ４ ＋ ), sulfate (-SO ４ － ), sulfonate (-SO ３ － ), phosphate (-PO ４ ２－ ), phosphonate (-PO ３ ２－ ), and hydrocarbyls containing 1 to 50 carbon atoms (heteroatom means O, N, or S), which may be optionally substituted with one or more heteroatom-containing groups and / or which may be interrupted by one or more heteroatoms or heteroatom-containing groups and / or which may optionally form an aromatic or non-aromatic ring which may be interrupted by one or more heteroatoms or heteroatom-containing groups.

2. The thionolactone of formula I according to claim 1, wherein X is O.

3. R １ 、 R ２ 、 R ３ 、 and R ４ 、 as well as R １ ’, R ２ ’, R ３ ’, R ４ ’, and R ５ ’ are each independently selected from the group consisting of hydrocarbyls containing 1 to 50 carbon atoms, which are substituted with one or more heteroatom-containing groups selected from -H, -F, -Cl, -Br, hydroxyl (-OH), thio (-SH), nitro group (-NO ２ ), amine (-NH ２ ), ammonium (-NH ４ ＋ ), sulfate (-SO ４ － ), sulfonate (-SO ３ － ), as well as -OY, -NHY, -NY ２ , -SY, and / or are each sandwiched between one or more heteroatoms or heteroatom-containing groups selected from -O-, -NY-, -S-. Y means H or a branched or straight-chain alkyl containing 1 to 12 carbon atoms, preferably a straight-chain alkyl containing 1 to 6 carbon atoms. The thionolactone of formula I according to claim 1 or 2.

4. R １ 、 R ２ 、 R ３ 、 R ４ 、 R １ ’、 R ２ ’、 R ３ ’、 R ４ ’、 or R ５ ’ among them, preferably R ３ or R ３ ’ is a polyethylene glycol group of the formula -(CH ２ -CH ２ -O) ｎ -H, and n is an integer varying in the range of 1 to 25, preferably 1 to 18, more preferably 1 to 12. The thionolactone of formula I according to claim 1 or 2.

5. At least R １ , R １ ’, and R ５ ’ is H, the thionolactone of formula I according to claim 1 or 2.

6. R １ , R ２ , R ３ , and R ４ , as well as R １ ’, R ２ ’, R ３ ’, R ４ ’, and R ５ ’ is H, the thionolactone of formula I according to claim 1 or 2.

7. A compound of formula II [Chemical 2] (wherein X, R １ , R ２ , R ３ , and R ４ , and R １ ’, R ２ ’, R ３ ’, R ４ ’, and R ５ ’ are as defined in claim 1 or 2) A process for preparing the thionolactone according to claim 1 or 2 by reacting with a sulfurizing agent.

8. The vulcanizing agent is Lawesson's reagent (2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide), Davy's reagent (2,4-bis(methylthio)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane, (CH ３ S) ２ P ２ S ４ ), Curphey's reagent (hexamethyldisiloxane (HMDO) / phosphorus pentasulfide (P ４ S １０ ), Kaushik's reagent (P ４ S １０ / Al ２ O ３ ), Bernthen's reagent (S ８ / I ２ ), Heimgartner's reagent (2,4-bis(4-methylphenylthio)-1,3,2λ5,4λ5-dithiadiphosphetane-2,4-dithione), Jan Bergman reagent, Belleau reagent (2,4-bis(4-phenoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide), Japanese reagent (2,4-bis(phenylthio)-1,3,2,4-dithiadiphosphetane 2,4-disulfide), H ２ S, CS ２ , R ２ PSX, (Et ２ Al) ２ S, NaSH, TMS ２ S, thiourea / Ru(III) / Al ２ O ３ , benzyltriethylammonium tetrathiomolybdate, thioacyl-N-phthalimide, elemental sulfur, aqueous ammonium sulfide solution, SiS ２ , hexamethyldisilathiane (HMDSTh), PSCl ３ / H ２ O / Et ３ N, polymer-supported vulcanizing agent and in situ vulcanizing agent, P ２ S ５ / Na ２ CO ３ The method according to claim 7, selected from the group consisting of, and preferably Lawesson's reagent.

9. Use of the thionolactone of formula I according to claim 1 or 2 as a comonomer for preparing a copolymer.

10. A copolymer comprising a repeating unit of formula III 【Chemical Formula 3】 (wherein X, R １ , R ２ , R ３ , and R ４ , and R １ ’, R ２ ’, R ３ ’, R ４ ’, and R ５ ’ are as defined in claim 1) and at least one other repeating unit.

11. The copolymer according to claim 10, wherein the at least one other repeating unit is derived from a comonomer selected from the group consisting of alkyl acrylate, N-alkylacrylamide, N,N-dialkylacrylamide, styrene and styrene derivatives, preferably 4-substituted styrene derivatives, acrylonitrile, and mixtures thereof, and "alkyl" means a linear or branched alkyl group containing 1 to 12 carbons, preferably 1 to 6 carbons.

12. The copolymer according to claim 10 or 11, wherein the at least one other repeating unit is selected from the group consisting of the following formulas IV, V, VI: 【Chemical Formula 4】 and mixtures thereof.

13. A process for preparing the copolymer according to claim 10, wherein the thionolactone of formula I according to claim 1 is copolymerized with at least one other comonomer selected from the group consisting of N,N-dimethylacrylamide, styrene, and methyl acrylate, preferably.

14. Use of the thionolactone of formula I as a comonomer for imparting degradation properties to a copolymer partially produced from the thionolactone of formula I according to claim 1 or 2.

15. A method for degrading the copolymer according to claim 10, wherein the copolymer is reacted with a degradation reagent selected from the group consisting of a base, an amine, and an oxidizing agent, preferably a base, in an organic or aqueous medium.

16. Use of the thionolactone of formula I as a comonomer for introducing a functional group into a copolymer partially produced from the thionolactone of formula I according to claim 1 or 2.

17. The method for functionalizing the copolymer according to claim 10, wherein the copolymer is reacted with a decomposition reagent selected from the group consisting of a base, an amine, and an oxidizing agent, preferably a base, in an organic medium or an aqueous medium.

18. An oligomer obtained by the method for decomposing the copolymer according to claim 15 or by the method for functionalizing the copolymer according to claim 17.

Images