Photoactivatable resin compositions and their use in 3D printing

Abstract

The present invention relates to a photoactivatable resin composition comprising a multifunctional acrylate or methacrylate monomer, a cyclic monomer comprising a cleavable or pre-cleavable group, and a photoinitiator. The present invention also relates to degradable polymers, degradable 3D printed articles, and methods for producing such polymers and articles. The present invention further relates to the use of monomers comprising cyclic methacrylates of thionolactones or sulfides for producing degradable 3D printed articles.

Description

[Technical field]

[0001] The present invention relates to a photoactivatable resin composition comprising a multifunctional acrylate or methacrylate monomer, a cyclic monomer comprising a cleavable or pre-cleavable group, and a photoinitiator. The present invention also relates to degradable polymers, degradable 3D printed articles, and methods for producing such polymers and articles. The present invention further relates to the use of monomers comprising cyclic methacrylates of thionolactones or sulfides for producing degradable 3D printed articles. [Background technology]

[0002] Additive manufacturing, and more specifically 3D printing, has revolutionized traditional industrial production by directly creating computer-designed 3D objects using successive layering of materials. The rapid development of this technology was initially driven by the ease of the Fused Deposition Modeling (FDM) technique, which allows the production of 3D objects by computer-controlled layer-by-layer deposition of molten or semi-molten polymers through an extrusion nozzle. However, 3D printing has become extremely popular with the development of photocuring methods, usually referred to as liquid vat photopolymerization. Among these methods, digital light processing (DLP) has been of particular interest due to several attractive features, such as fast build-up, low resolution (<100 μm models), wide ink viscosity tolerance, and low cost. This method allows the fabrication of 3D objects by crosslinking of liquid resins, mainly composed of multifunctional methacrylate or acrylate derivatives. The photopolymerization of acrylates occurs rapidly with high yields and produces almost no by-products. This results in crosslinked materials whose mechanical properties can be tailored by the monomer structure. Furthermore, these objects are composed of a covalent network of C-C bonds that confers high thermal and chemical stability.

[0003] However, the developed bath photopolymerization methods show several drawbacks so far. First, the high stability is not compatible with easy degradability and recyclability / upcyclability. Large amounts of 3D printing resins end up being incinerated and stored in landfills, making this very promising manufacturing method not environmentally friendly or sustainable. Second, this high stability is also not compatible with subtractive manufacturing methods, techniques in which the printed material can be removable or erasable after its formation. Such approaches are of great interest as they easily remove the template or sacrificial parts of the 3D object, a technique widely used when the object is a positive print before casting and finally disassembled to produce jewelry or ceramics.

[0004] To overcome these shortcomings, several solutions have been proposed. Barner-Kowollik and coll. describe the preparation of resins using novel monomers based on either thiol-ene chemistry, TAD-polyether ligation, silane-based monomers, o-nitrobenzyl ester monomers, and chymotrypsin-cleavable monomers (Adv. Funct. Mater. 2018, 1801405; Adv. Mater. 2020, 32, e2003060; Nat. Commun. 2018, 9, 2788 pages; Adv. Mater. 2019, 31, e1904085; Adv. Funct. Mater. 2020, 2006998). Stimulated and / or controlled degradation of such resins has been obtained. However, these strategies are not applicable on an industrial scale, especially since the monomers used to prepare the resins are expensive compared to the acrylate or methacrylate monomers conventionally used in industry.

[0005] Zhao and coll. (Adv. Funct. Mater. 2020, 2007173) and Bowman and coll. (Materials Horizons, 2020, 7, 835) reported 3D printing of linear polymers as a way to impart reprintability or recyclability to printed objects. However, such materials have lower chemical resistance, especially due to the solubility of the polymers in organic solvents. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Adv. Funct. Mater. 2018, 1801405 [Non-Patent Document 2] Adv. Mater. 2020, 32, e2003060 [Non-Patent Document 3] Nat. Commun. 2018, 9, 2788 pages [Non-Patent Document 4] Adv. Mater. 2019, 31, e1904085 [Non-Patent Document 5] Adv. Funct. Mater. 2020, 2006998 [Non-Patent Document 6] Adv. Funct. Mater. 2020, 2007173 [Non-Patent Document 7] Materials Horizons, 2020, 7, 835 pages [Non-Patent Document 8] Smith et al., J. Am. Chem. Soc. 2019, 141(4), p. 1446 [Non-Patent Document 9] O. Soppera et al., J Polym Sci Pol Chem 2003, 41, 716 [Non-Patent Document 10] Bingham et al., Chem. Commun. 2019, 55, pp. 55-58 [Non-Patent Document 11] Bailey et al., J. Polym. Sci. Part A Polym. Chem. 1982, 20, pp. 3021-3030 [Non-Patent Document 12] Chem. Soc. 2013, 19, page 2606 [Non-Patent Document 13] J. Am. Chem. Soc. 2009, 131, 9805 pages [Non-Patent Document 14] OB Peersen, X. Wu, I. Kustanovich, SO Smith, J. Magn. Reson. 1993, 104, pp. 334-339. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, there remains a need to provide cost-effective resins that have suitable mechanical and chemical properties for use in 3D printing and are easily degradable. [Means for solving the problem]

[0008] In this regard, the inventors have developed resins that can be produced by photopolymerization of a composition comprising a multifunctional acrylate and / or methacrylate monomer (M1), a cyclic monomer (M2) capable of undergoing radical ring opening, containing a cleavable or pre-cleavable moiety such as thiocarbonyl-oxy, carbonyl-oxy, carbonyl-thio, disulfide, silyl ether, or acetal, and having a polymerization rate that is comparable to or faster than that of the acrylate and / or methacrylate monomer, and a photoinitiator. The inventors have demonstrated that by incorporating the monomer M2, the resin can be effectively decomposed by using standard decomposition conditions. Moreover, only a very small amount of the monomer M2 is required, such that the chemical and mechanical properties of the resin are the same as those of the corresponding resin lacking such monomer M2. Moreover, the monomer M2 can be directly incorporated into the resin composition, thus imparting decomposability to conventional and commercially available resins, thus avoiding the need to develop new resin compositions. The resin of the present invention has been successfully applied to 3D printing, particularly vat photopolymerization, and effective degradation of 3D printed parts has been observed.

[0009] Accordingly, the present invention provides a photoactivatable resin composition comprising: - a first monomer (M1) comprising at least two functional groups independently selected from an acrylate functional group and a methacrylate functional group; - a second monomer (M2) which is a cyclic monomer capable of undergoing radical ring opening and which comprises a moiety selected from the group consisting of thiocarbonyl-oxy, carbonyl-oxy, carbonyl-thio, disulfide, silyl ether, and acetal, and wherein the polymerization rate of M2 is comparable to or faster than the polymerization rate of M1; - Photoinitiator and The present invention relates to a photoactivatable resin composition comprising:

[0010] The present invention also relates to degradable polymers based on the photoactivatable resin composition defined herein.

[0011] The present invention also relates to a method of photopolymerization comprising the step of irradiating the photoactivatable resin composition as defined herein.

[0012] Another object of the present invention is a method for 3D printing a degradable molded article, comprising the step of irradiating a photoactivatable resin composition as defined herein under conditions allowing the formation of a 3D molded article.

[0013] Another object of the present invention is a degradable 3D printed article based on the degradable polymers defined herein.

[0014] A further object of the present invention is the use of a monomer comprising a cyclic methacrylate of a thionolactone or sulfide as defined herein for producing a degradable 3D printed article as defined herein. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 shows the photopolymerization kinetics by FTIR (transformation of C=C band at 1635 cm-1) under UV exposure of resin compositions containing: i) PETIA+0.2% BAPO+2% DOT (filled circles); ii) PETIA+0.5% BAPO+2% DOT (filled triangles); iii) PETIA+0.5% BAPO (x). [Diagram 2] a) Image of a molded part produced by DLP printing using a resin of the present invention (PETIA + 0.2% BAPO + 2% DOT); b) Image of a molded part produced by 3D printing using a resin of the present invention (PETIA + 0.2% BAPO + 2% DOT). [Diagram 3] FIG. 1 shows a dissolution experiment using 5% KOH in MeOH / THF of a microchip made with a resin of the invention (PETIA+0.2% BAPO+2% DOT) compared to a microchip of a comparative resin (no DOT). [Figure 4] 1 is a graph showing degradation times for 6 μm and 10 μm microchips made with a resin of the present invention (PETIA+0.2% BAPO+2% DOT) under various degradation conditions. [Diagram 5] FIG. 1 shows the degradation of a macroscopic part formed by DLP-UV set-up printing of a resin of the present invention (PETIA+0.2% BAPO+2% DOT) using 5% KOH in MeOH / THF. [Figure 6] FIG. 1 shows the degradation of hollow cubes formed by 3D printing of a resin of the invention (PETIA+0.2% BAPO+2% DOT) and a comparative resin (no DOT) in a 5% by weight solution of KOH in MeOH / THF at room temperature without stirring (top), and the biodegradation of these 3D printed hollow cubes in homemade compost (bottom). [Figure 7] FIG. 1 shows the decomposition of the Eiffel Tower formed by 3D printing of a resin of the invention (PETIA+0.2% BAPO+2% DOT) and a comparative resin (no DOT) in a 5 wt % solution of KOH in MeOH / THF at room temperature without stirring. [Figure 8] FIG. 13 shows the disassembly of stacked dice formed by 3D printing of a resin of the invention (PETIA+0.2% BAPO+2% DOT) and a comparative resin (no DOT) in a 5 wt % solution of KOH in MeOH / THF at room temperature without stirring. [Figure 9] FIG. 1 shows a particular method of manufacturing a molded article in which a non-degradable object made from the resin PETIA+0.2% BAPO is embedded in a degradable object made from the resin of the invention (PETIA+0.2% BAPO+2% DOT). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] As used in this disclosure, the term "C x ~C y" means that the corresponding hydrocarbon chain contains x to y carbon atoms. For example, when the term C1-C6 is used, it means that the corresponding hydrocarbon chain may contain 1 to 6 carbon atoms, particularly 1, 2, 3, 4, 5, or 6 carbon atoms. For example, when the term C2-C5 is used, it means that the corresponding hydrocarbon chain may contain 2 to 5 carbon atoms, particularly 2, 3, 4, or 5 carbon atoms.

[0017] The term "alkyl" refers to a saturated, straight or branched chain aliphatic group. The term "C1-C6 alkyl" refers to an alkyl having 1 to 6 carbon atoms. Examples of alkyl (or C1-C6 alkyl) include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, or hexyl.

[0018] The term "alkenyl" refers to an unsaturated, straight or branched chain aliphatic group having at least one carbon-carbon double bond. The term "C2-C6 alkenyl" refers to an alkenyl having 2 to 6 carbon atoms. The term alkenyl (or C2-C6 alkenyl) includes, for example, ethenyl, propenyl, butenyl, pentenyl, or hexenyl.

[0019] The term "alkynyl" refers to an unsaturated, straight or branched chain aliphatic group having at least one carbon-carbon triple bond. The term "C2-C6 alkynyl" refers to an alkynyl having 2 to 6 carbon atoms. The term alkynyl (or C2-C6 alkynyl) includes, for example, ethynyl, propynyl, butynyl, pentynyl, or hexynyl.

[0020] The term "heteroalkyl" refers to an alkyl as defined herein, in which the aliphatic carbon chain contains and / or is interrupted by at least one heteroatom, such as O, N, or S, at one or both of its two ends (particularly the end attached to the remainder of the molecule). Examples of heteroalkyl are, inter alia, alkoxy (-O-alkyl), alkylthio (-S-alkyl), and alkylamino (-NH(alkyl) or -N(alkyl)2).<C1~C6ヘテロアルキル> > refers to heteroalkyl having 1-6 carbon atoms and at least one heteroatom, such as O, N, or S. Examples of heteroalkyl (or C1-C6 heteroalkyl) include, but are not limited to, methoxy, ethoxy, propyloxy, isopropyloxy, butyloxy, isobutyloxy, tert-butyloxy, pentyloxy, hexyloxy, methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio, tert-butylthio, pentylthio, hexylthio, methylamino, ethylamino, propylamino, isopropylamino, butylamino, isobutylamino, tert-butylamino, pentylamino, or hexylamino.

[0021] The term "cycloalkyl" refers to a saturated or unsaturated, monocyclic, bicyclic, or tricyclic aliphatic group. It also includes fused, bridged, or spiro-linked cycloalkyl groups. The term "C3-C 12 "Cycloalkyl" refers to a cycloalkyl having 3 to 12 carbon atoms. Cycloalkyl (or C 12 Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, or cyclododecyl. The term "cycloalkyl" can also refer to bridged carbocyclyls, such as bicyclo[2,2,1]heptanyl, bicyclo[2,2,2]octanyl, or adamantyl, preferably bicyclo[2,2,1]heptanyl.

[0022] The term "heterocycloalkyl" corresponds to a saturated or unsaturated cycloalkyl group as defined above, in which at least one carbon atom is replaced by a heteroatom selected from a nitrogen atom, an oxygen atom, or a sulfur atom. Advantageously, the heterocycloalkyl contains between 3 and 12 ring atoms, at least one of the ring atoms being a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. In the case of bicyclic or tricyclic rings, the rings may be fused, bridged, or have a spiro configuration. The term heterocycloalkyl includes, for example, aziridinyl, azepanyl, diazepanyl, dioxolanyl, benzo[1,3]dioxolyl, azetidinyl, oxetanyl, pyrazolinyl, pyranyl, thiomorpholinyl, pyrazolidinyl, piperidyl, piperazinyl, 1,4-dioxanyl, imidazolinyl, pyrrolinyl, pyrrolidinyl, piperidinyl, imidazolidinyl, morpholinyl, 1,4-dithianyl, pyrrolidinyl, pyrimidinyl, oxozolinyl, nyl), oxazolidinyl, isoxazolinyl, isoxazolidinyl, thioxetanyl, thiopyranyl, thiomorpholinyl, thiazolinyl, thiazolidinyl, isothiazolinyl, isothiazolidinyl, dihydropyranyl, dihydrofuranyl, dihydrothiopyranyl, dihydrothiophenyl, dihydropiperidinyl, tetrahydropiperidinyl, tetrahydrothiopyranyl, tetrahydropyranyl, tetrahydrofuranyl, and tetrahydrothiophenyl.

[0023] "Cycloalkyl" and "heterocycloalkyl" also include cycloalkenyl and heterocycloalkenyl, corresponding to cycloalkyl having at least one carbon-carbon double bond, and heterocycloalkyl having at least one carbon-carbon double bond, respectively, e.g., cyclohexenyl and dihydropyranyl.

[0024] The term "aryl" refers to a monocyclic or bicyclic aromatic hydrocarbon having 6 to 12 carbon atoms. For example, the term "aryl" includes phenyl, biphenyl, or naphthyl. In a preferred embodiment, aryl is phenyl.

[0025] As used herein, the term "heteroaryl" corresponds to an aromatic monocyclic or polycyclic group containing between 5 and 14 ring atoms, at least one of which is a heteroatom, such as a nitrogen atom, an oxygen atom, or a sulfur atom. As used herein, the term "heteroaryl" further includes "fused arylheterocycloalkyl" and "fused heteroarylcycloalkyl". The terms "fused arylheterocycloalkyl" and "fused heteroarylcycloalkyl" correspond to a bicyclic group in which an aryl or heteroaryl as defined above is bonded by at least two carbons to a heterocycloalkyl or cycloalkyl as defined above, respectively. In other words, the aryl or heteroaryl shares a carbon bond with the heterocycloalkyl or cycloalkyl.Examples of monocyclic and polycyclic heteroaryl groups, fused arylheterocycloalkyls, and fused arylcycloalkyls are pyridinyl, thiophenyl, furanyl, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, tetrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, tetrazolyl, benzofuranyl, thianaphthalenyl, indolyl, indolinyl, indanyl, quinolinyl, isoquinolinyl, benzimidazolyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, triazinyl, thianthrenyl, benzofuranyl, dihydrobenzofuranyl, isobenzofuranyl, benzothiophenyl, isobenzothiophenyl, chromenyl, xanthenyl, phenoxanthinyl, pyrazinyl, pyradazinyl, indolizinyl, isoindolyl, indazolyl, purinyl. , quinolidinyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, carbazolyl, β-carbolinyl, phenanthridinyl, acridinyl, pyrimidinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, furazanyl, phenoxazinyl, isochromanyl, chromanyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, pyrazolinyl, indolinyl, isoinyl It may be dolinyl, oxazolidinyl, benzotriazolyl, benzisoxazolyl, oxyindolyl, benzoxazolyl, benzoxazolinyl, benzoxazinyl, benzothienyl, benzothiazolyl, benzodiazepinyl, benzazepinyl, benzoxazepinyl, isatinyl, dihydrobenzodioxepinyl, dihydropyridyl, pyrimidinyl, s-triazinyl, oxazolyl, or thiofuranyl. Fused arylheterocycloalkyl is, for example, indolinyl (phenyl fused to pyrrolidinyl) and dihydrobenzofuranyl (phenyl fused to dihydrofuranyl).

[0026] The term "carbocycle" refers to a saturated or unsaturated, aliphatic or aromatic, monocyclic or polycyclic hydrocarbon group. 12 "Carbocycle" refers to a carbocycle having 3 to 12 carbon atoms. In one particular embodiment,12 Carbocyclic rings are C3 to C 12 It is cycloalkyl or aryl.

[0027] The term "perfluoroalkyl" refers to an alkyl as defined above, in which all hydrogen atoms are replaced with fluorine atoms. The term "C1-C6 perfluoroalkyl" refers to a perfluoroalkyl having 1-6 carbon atoms. An example of a perfluoroalkyl (or C1-C6 perfluoroalkyl) includes, but is not limited to, trifluoromethyl.

[0028] The term "halogen" corresponds to a fluorine, chlorine, bromine or iodine atom, preferably fluorine, chlorine or bromine, more preferably chlorine or fluorine.

[0029] The term "ester" refers to the group -C(O)OR or RC(O)O-, where R is any hydrocarbon group. In a particular embodiment, R is C1-C6 alkyl, C3-C 12 It is cycloalkyl or aryl.

[0030] The term "ketone" refers to the group -C(O)R', where R' is any hydrocarbon group. In a particular embodiment, R' is C1-C6 alkyl, C3-C 12 It is cycloalkyl or aryl.

[0031] The term "amide" refers to the group -C(O)N(R"), where each R is independently hydrogen or a hydrocarbon group. In a particular embodiment, each R is independently hydrogen, C1-C6 alkyl, C3-C6 alkyl, C1-C6 alkyl, C2 ...1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C6 alkyl, C1-C 12 It is cycloalkyl or aryl.

[0032] The term "sulfonyl" refers to the group -S(O)2-R''', where R''' is any hydrocarbon group. In one particular embodiment, R''' is C1-C6 alkyl, C3-C 12 It is cycloalkyl or aryl.

[0033] The term "alkylene" refers to a divalent, saturated, straight or branched chain aliphatic group. Examples of alkylene having 1 to 11 carbon atoms include, but are not limited to, methylene, ethylene, propylene, butylene, isobutylene, pentylene, isopentylene, hexylene, heptylene, octylene, nonylene, decylene, or undecylene.

[0034] The alkyl, alkenyl, alkynyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, carbocycle, and alkylene groups defined herein are optionally substituted. The phrase "optionally substituted" means unsubstituted or substituted with one or more (e.g., 1, 2, 3, or 4, preferably 1 or 2, more preferably 1) substituents. Examples of substituents include, but are not limited to, C1-C6 perfluoroalkyl (e.g., -CF3), nitro (-NO2), cyano (-CN), -SO3H, -OH, -SH, -NH2, -COOH, halogen, C1-C6 alkyl, C3-C6 aryl, C4-C6 aryl, C5-C6 aryl, C6-C6 aryl, C7-C6 aryl, C8-C6 aryl, C9-C10 aryl, C11-C12 aryl, C12-C14 aryl, C13-C15 aryl, C14-C16 aryl, C15-C16 aryl, C16-C17 aryl, C17-C18 aryl, C18-C19 aryl, C19-C20 aryl, C19-C21 aryl, C19-C22 aryl, C19-C23 aryl, C19-C24 aryl, C19-C25 aryl, C21-C26 aryl, C22-C25 aryl, C22-C26 ... 12 Examples include cycloalkyl, aryl, ester, and ketone.

[0035] In the present specification, the expression "photoactivatable resin composition" refers to a composition, typically in the form of a liquid solution or suspension, which can be converted into a resin by photoactivation. Photoactivation is activation by any light, typically consisting of one or more wavelengths comprised between 100 nm and 1500 nm. Preferably, said light is ultraviolet (UV) light, visible light or near infrared (IR) light, preferably UV light. UV light typically has a wavelength comprised between 100 nm and 390 nm. Visible light typically has a wavelength comprised between 390 nm and 700 nm. Near IR light typically has a wavelength comprised between 700 nm and 1500 nm.

[0036] The photoactivatable resin composition of the present invention comprises: - a first monomer (M1) comprising at least two functional groups independently selected from acrylate and / or methacrylate functional groups; - a second monomer (M2) which is a cyclic monomer capable of undergoing radical ring opening, the second monomer (M2) comprising a moiety selected from the group consisting of thiocarbonyl-oxy, carbonyl-oxy, carbonyl-thio, disulfide, silyl ether, and acetal, and the polymerization rate of M2 is comparable to or faster than the polymerization rate of M1; - Photoinitiator and Includes.

[0037] The first monomer M1 is a multifunctional acrylate and / or methacrylate monomer or a mixture of various multifunctional acrylate and / or methacrylate monomers. The first monomer M1 comprises at least two (e.g., two, three, four, or five, preferably two or three, more preferably three) functional groups independently selected from acrylate and methacrylate functional groups.

[0038] The acrylate functional group may specifically be represented as follows:

[0039] [ka]

[0040] (In the formula,

[0041] [ka]

[0042] indicates the bond by which the acrylate functional group is attached to the remainder of the first monomer)

[0043] The methacrylate functional group may specifically be represented as follows:

[0044] [ka]

[0045] (In the formula,

[0046] [ka]

[0047] indicates the bond by which the methacrylate functional group is attached to the remainder of the first monomer.

[0048] In one particular embodiment, the first monomer M1 comprises at least two (e.g., two, three, four, or five, preferably two or three, more preferably three) functional groups, each of which is an acrylate functional group. In a more detailed embodiment, the first monomer M1 is selected from pentaerythritol triacrylate (PETIA), pentaerythritol tetra-acrylate (PETEA), propoxylated glycerin triacrylate (EB53), glycerol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate (TMPTA or TTA), di(trimethylolpropane) tetra-acrylate (DTMPTA), ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate (PEGDA), propylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, bisphenol A ethoxylate diacrylate (bis-EDA), and mixtures thereof.

[0049] In another particular embodiment, the first monomer M1 comprises at least two (e.g., two, three, four, or five, preferably two or three, more preferably three) functional groups, each of which is a methacrylate functional group. In another more detailed embodiment, the first monomer M1 is selected from the group consisting of ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate (TEGDMA), polyethylene glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2-bis-4-(methacryloxyethoxy)phenylpropane, tricyclodecane dimethanol dimethacrylate, 1,10-decanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, neopentyl glycol dimethacrylate, 1,2-dimethylphenyl dimethacrylate, 1,3-dimethylphenyl dimethacrylate, 1,4-dimethylphenyl dimethacrylate, 1,5-dimethylphenyl dimethacrylate, 1,6-dimethylphenyl dimethacrylate, 1,7-dimethylphenyl dimethacrylate, 1,8-dimethylphenyl dimethacrylate, 1,9-dimethylphenyl dimethacrylate, 1,8-dimethylphenyl dimethacrylate, 1,9-dimethylphenyl dimethacrylate, 1,9-dimethylphenyl dimethacrylate, 1,10-dimethylphenyl dimethacrylate, 1,6-dimethylphenyl dimethacrylate, 1,9-dimethylphenyl dimethacrylate, 1,2-dimethylphenyl dimethacrylate, 1,3-dimethylphenyl dimethacrylate, 1,4-dimethylphenyl dimethacrylate, 1,5-dimethylphenyl dimethacrylate, 1,6-dimethylphenyl dimethacrylate, 1,7-dimethylphenyl dimethacrylate, 1,8-dimethylphenyl dimethacrylate, 1,9-dimethylphenyl dimethacrylate, 1,9-dimethylphenyl dimethacrylate, 1,5-dimethylphenyl dimethacrylate, 1,5-dimethylphenyl dimethacrylate, 1,6-dimethylphenyl dimethacrylate, 1,7-dimethylphenyl dimethacrylate, 1,8 acrylate, 2-hydroxy 1,3-dimethacryloxypropane, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate, ditrimethylolpropane tetramethacrylate, tris(2-hydroxyethyl)isocyanurate trimethacrylate, diurethane dimethacrylate (UDMA), dipentaerythritol pentamethacrylate, ethoxylated pentaerythritol tetramethacrylate, propoxylated glyceryl trimethacrylate, propoxylated trimethylolpropane trimethacrylate, bisphenol A glycidyl methacrylate (bis-GMA), and mixtures thereof.

[0050] In a preferred embodiment, the first monomer is selected from pentaerythritol triacrylate (PETIA), pentaerythritol tetra-acrylate (PETEA), propoxylated glycerin triacrylate (EB53), glycerol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate (TMPTA or TTA), di(trimethylolpropane) tetra-acrylate (DTMPTA), triethylene glycol dimethacrylate (TEGDMA), polyethylene glycol diacrylate (PEGDA), diurethane dimethacrylate (UDMA), bisphenol A glycidyl methacrylate (bis-GMA), bisphenol A ethoxylate diacrylate (bis-EDA), and mixtures thereof.

[0051] In a more preferred embodiment, the first monomer M1 is PETIA.

[0052] The molecular weight of the first monomer M1 is not particularly limited. Typically, the molecular weight is between 50 and 800 g / mol, for example, between 500 and 800 g / mol.

[0053] In one particular embodiment, the first monomer M1 is in prepolymer (or equivalently "oligomer") form. In such an embodiment, the molecular weight of the prepolymer may be, for example, comprised between 100 and 100000 g / mol.

[0054] The amount of first monomer M1 in the composition of the invention advantageously ranges from 1 to 98.9% by weight, preferably from 10 to 98.9% by weight, more preferably from 40 to 98.9% by weight and even more preferably from 60 to 98% by weight relative to the total weight of the composition.

[0055] The second monomer M2 is a cyclic monomer capable of undergoing radical ring opening that comprises a moiety selected from the group consisting of thiocarbonyl-oxy (-C(S)O- or equivalently -OC(S)-), carbonyl-oxy (i.e., -C(O)O- or equivalently -OC(O)-), carbonyl-thio (i.e., -C(O)S- or equivalently -SC(O)-), disulfide, silyl ether, and acetal, and has a polymerization rate that is comparable to or faster than that of M1.

[0056] Preferably, the second monomer M2 is a cyclic monomer capable of undergoing radical ring opening comprising a moiety selected from the group consisting of thiocarbonyl-oxy (-C(S)O- or equivalently -OC(S)-), carbonyl-oxy (i.e., -C(O)O- or equivalently -OC(O)-), carbonyl-thio (i.e., -C(O)S- or equivalently -SC(O)-), disulfide, and silyl ether, and having a polymerization rate that is comparable to or faster than that of M1.

[0057] Preferably, the second monomer M2 is a cyclic monomer capable of undergoing radical ring opening comprising a moiety selected from the group consisting of thiocarbonyl-oxy (-C(S)O- or equivalently -OC(S)-), carbonyl-oxy (i.e., -C(O)O- or equivalently -OC(O)-), carbonyl-thio (i.e., -C(O)S- or equivalently -SC(O)-) and having a polymerization rate comparable to or faster than that of M1.

[0058] In one particular embodiment, the second monomer M2 is a cyclic monomer capable of undergoing radical ring opening that contains a thiocarbonyl-oxy moiety (-C(S)O- or equivalently -OC(S)-) and has a polymerization rate that is comparable to or faster than that of M1.

[0059] Preferably, the second monomer M2 is a cyclic monomer capable of undergoing radical ring-opening comprising a moiety selected from the group consisting of carbonyl-oxy (i.e., -C(O)O- or equivalently -OC(O)-) or carbonyl-thio (i.e., -C(O)S- or equivalently -SC(O)-) and having a polymerization rate comparable to or faster than that of M1.

[0060] As used herein, a cyclic monomer "capable of undergoing radical ring-opening" refers to a cyclic compound that can be chain-opened by a radical species, the radical species derived, for example, from a photoinitiator or a growing polymer chain. More specifically, the chain-opening can occur by addition of the radical species to a site of a monomer, typically followed by interruption of a bond in the cyclic chain adjacent to the site.

[0061] According to the invention, the polymerization rate of monomer M2 is comparable (preferably "equal") to or faster than the polymerization rate of monomer M1 (or each of the monomers M1, if a mixture of monomers M1 is contained in the composition).

[0062] The expression "similar to the polymerization rate of monomer M1" means ±20% of the polymerization rate of monomer M1, preferably ±10% of the polymerization rate of monomer M1, more preferably ±5% of the polymerization rate of monomer M1.

[0063] In one particular embodiment, the ratio of the polymerization rate of M2 to that of M1 is comprised between 0.8 and 1.2, preferably between 0.9 and 1.1. The polymerization rates or the ratio of the polymerization rates of the monomers is 1 By H NMR or infrared spectroscopy (preferably 1 The measurement of the polymerization rate or the polymerization rate ratio of the monomers can be determined, inter alia, by H NMR spectroscopy. The measurement of the polymerization rate or the polymerization rate ratio of the monomers can be described in Smith et al., J. Am. Chem. Soc. 2019, 141(4), 1446 or O. Soppera et al., J Polym Sci Pol Chem 2003, 41, 716.

[0064] The second monomer comprises a cleavable or pre-cleavable moiety selected from the group consisting of thiocarbonyl-oxy (-C(S)O- or equivalently -OC(S)-), carbonyl-oxy (i.e., -C(O)O- or equivalently -OC(O)-), carbonyl-thio (i.e., -C(O)S- or equivalently -SC(O)-), disulfide (-SS-), silyl ether, and acetal.

[0065] As used herein, a "cleavable moiety" refers to a moiety that is cleavable, preferably selectively cleavable, by a chemical or biological reaction.

[0066] As used herein, the term "pre-cleavable moiety" refers to a moiety that can be converted to a cleavable moiety after radical ring-opening of the monomer M2. For example, the second monomer M2 can contain a pre-cleavable moiety, thiocarbonyl-oxy, that can be converted to a cleavable carbonyl-thio after radical ring-opening of the monomer.

[0067] The cleavable or pre-cleavable moiety is preferably contained within the cyclic structure of the second monomer.

[0068] As used herein, "silyl ether" refers to a moiety of the formula:

[0069] [ka]

[0070] (In the formula,

[0071] [ka]

[0072] indicates the bond by which the functional group is attached to the remainder of the monomer). In monomers that contain silyl ethers, the Si-O atom is typically attached to a hydrocarbon chain that makes up the remainder of the monomer.

[0073] As used herein, "acetal" refers to a moiety of the formula:

[0074] [ka]

[0075] (In the formula,

[0076] [ka]

[0077] indicates the bond by which the functional group is attached to the remainder of the monomer). In acetal-containing monomers, the OCO atom is typically attached to a hydrocarbon chain that makes up the remainder of the monomer.

[0078] In one particular embodiment, the second monomer comprises a thiocarbonyl-oxy. Such a moiety is typically a pre-cleavable moiety.

[0079] In another particular embodiment, the second monomer comprises a carbonyl-oxy or carbonyl-thio moiety. Such moieties are typically cleavable.

[0080] In one embodiment, the second monomer M2 comprises a cyclic methacrylate of a thionolactone or a sulfide.

[0081] As used herein, "thionolactone" refers to a cyclic thionoester group, i.e., a cyclic group having a thiocarbonyl-oxy-C(S)O- (or equivalently -OC(S)-) group within the ring. Thionolactones may be diagrammed as follows:

[0082] [ka]

[0083] (wherein the circular arcs represent the hydrocarbon chains)

[0084] In one particular embodiment, the second monomer is represented by formula (Ia):

[0085] [ka]

[0086] (In the formula, - m is 0, 1, 2 or 3; - n is 0~(2m+5), - each R1 is independently hydrogen, halogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 heteroalkyl, C3-C 12 selected from the group consisting of cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cyano, nitro, -C(O)OH, -C(O)H, -OH, -SH, C1-C6 perfluoroalkyl, ester, ketone, sulfonyl, and amide; - R2 is hydrogen, halogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 heteroalkyl, C3-C 12 selected from the group consisting of cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cyano, nitro, -C(O)OH, -C(O)H, -OH, -SH, C1-C6 perfluoroalkyl, ester, ketone, sulfonyl, and amide; Or two adjacent R1, or adjacent R1 and R2, together with the carbon atom to which they are attached, form a C3-C 12 can form a carbocyclic ring (e.g., phenyl)

[0087] In the above formula (Ia), n represents the number of R1 substituting the cyclic ring. The maximum number of R1, i.e. (2m+5), depends on the size of the cyclic ring defined by m. For example, - if m=0, n is 0 to 5; - if m=1, n is 0 to 7; - if m=2, n is 0 to 9; - When m=3, n is 0 to 11.

[0088] Each R1 may be a substituent at any carbon atom of the ring, and formula (Ia) includes all combinations of substitutions. For example, in one embodiment where m=1 and n=2, formula (Ia) includes (but is not limited to) the following formulas:

[0089] [ka]

[0090] (wherein R1 and R2 are each as defined above). It should be understood that R1 may be different or the same.

[0091] In one particular embodiment, the second monomer is a compound of formula (Ia), wherein m is 2.

[0092] In another particular embodiment, the second monomer is a compound of formula (Ia) where n is 0, 1, 2, 3, or 4. Preferably, n is 0 or 1.

[0093] In one embodiment, where n is 0, the compound of formula (Ia) can be represented as follows:

[0094] [ka]

[0095] (wherein m and R2 are as defined above). In such embodiments, m is preferably 2.

[0096] It is understood that an embodiment in which n is 0 is equivalent to an embodiment in which n is different from 0 and all R1 are hydrogen.

[0097] In one embodiment where n is 1, the second monomer is a compound of formula (Ia), preferably a compound of formula (Ia) represented as follows:

[0098] [ka]

[0099] (wherein m, R1, and R2 are as defined herein). In such embodiments, m is preferably 2.

[0100] In a particular embodiment, R2 is selected from the group consisting of C2-C6 alkynyl, aryl, heteroaryl, cyano, nitro, -C(O)OH, -C(O)H, ester, ketone, sulfonyl, and amide. Preferably, R2 is cyano or aryl (preferred aryl is phenyl).

[0101] In another particular embodiment, each R1 is independently selected from the group consisting of hydrogen or C1-C6 alkyl; Or two adjacent R1, together with the carbon atom to which they are attached, form a C3-C 12 It is possible to form a carbocyclic ring (eg, phenyl).

[0102] In one embodiment where n is 1, R1 is preferably hydrogen or C1-C6 alkyl.

[0103] In a preferred embodiment, the second monomer is represented by any one of the following formulas:

[0104] [ka]

[0105] In a more preferred embodiment, the second monomer is represented by the formula (DOT):

[0106] [ka]

[0107] In another embodiment, the second monomer is represented by formula (Ia''-1) above.

[0108] In another embodiment, the second monomer is represented by formula (Ia''-2) above.

[0109] In another embodiment, the second monomer is represented by formula (Ia''-3) above.

[0110] As used herein, "sulfido cyclic methacrylate" refers to a cyclic group having within its cyclic structure a moiety as depicted below:

[0111] [ka]

[0112] (wherein X is O or S).

[0113] In one particular embodiment, the second monomer has the following formula (Ib):

[0114] [ka]

[0115] (In the formula, - X is O or S (preferably O), - L represents an alkylene chain having k carbon atoms, optionally interrupted by one or more (preferably one or two) groups independently selected from -C(O)O- and -SS-; - k is 1 to 11 (preferably 2 to 11, more preferably 2 to 8), - p is 0~(2k+2), - each R3 is independently hydrogen, halogen, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 heteroalkyl, C3-C 12 selected from the group consisting of cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cyano, nitro, -C(O)OH, -C(O)H, -OH, -SH, C1-C6 perfluoroalkyl, ester, ketone, sulfonyl, and amide; Or two adjacent R3 together with the carbon atom to which they are attached form a C3-C 12 can form a carbocyclic ring (e.g., phenyl)

[0116] In the above formula (Ib), k represents the number of carbon atoms in the alkylene chain, excluding the carbon atom in the optional group -C(O)O-.

[0117] In the above formula (Ib), p represents the number of R3 substituting the cyclic moiety. The maximum number of R3, i.e. (2k+2), depends on the size of the L chain defined by k. For example, - if k=1, p is between 0 and 4; - When k=2, p is 0 to 6.

[0118] Each R3 may be a substituent at any carbon atom of the ring, and formula (Ib) includes all combinations of substitutions. For example, in one embodiment where L is an alkylene having one carbon atom (k=1) and p=2, formula (Ib) includes the following formula:

[0119] [ka]

[0120] (wherein X and R3 are as defined above). It should be understood that R3 may be different or identical to each other.

[0121] In one particular embodiment, p is 0, 1, or 2 (preferably, p is 0). An embodiment in which p is 0 is understood to be equivalent to an embodiment in which p is different from 0 and all R3 are hydrogen.

[0122] In one particular embodiment, each R3 is selected from hydrogen and C1-C6 alkyl.

[0123] In another particular embodiment, L represents an alkylene chain having k carbon atoms, where k is 1 to 11 (preferably 2 to 11, more preferably 2 to 8).

[0124] In another particular embodiment, L represents an alkylene chain having k carbon atoms, where k is 1 to 11 (preferably 2 to 11, more preferably 2 to 8), interrupted by one -C(O)O- group and optionally further interrupted by one -SS- group.

[0125] In a preferred embodiment, the second monomer is represented by any one of the following formulas (SCM1) to (SCM7).

[0126] [ka]

[0127] In the composition of the present invention, the mass ratio of the second monomer M2 to the first monomer M1 may be 5 / 1000 to 95 / 5, preferably 1 / 100 to 20 / 100, more preferably 1 / 100 to 5 / 100, even more preferably 1 / 100 to 3 / 100, for example, 1.5 / 100 to 2.5 / 100.

[0128] In one particular embodiment, the composition of the invention advantageously comprises the first monomer M1 in an amount of 40 to 98.9% by weight, preferably 60 to 98% by weight, relative to the total weight of the composition, and has a weight ratio of the second monomer M2 to the first monomer M1 of 1 / 100 to 20 / 100, preferably 1 / 100 to 5 / 100, more preferably 1 / 100 to 3 / 100, for example 1.5 / 100 to 2.5 / 100.

[0129] In a more detailed embodiment, the composition of the invention advantageously comprises the first monomer M1 in an amount of 60 to 98% by weight relative to the total weight of the composition and has a weight ratio of the second monomer M2 to the first monomer M1 of 1 / 100 to 5 / 100, preferably 1 / 100 to 3 / 100, more preferably 1.5 / 100 to 2.5 / 100.

[0130] The composition of the present invention also includes a photoinitiator. As used herein, "photoinitiator" refers to an organic compound capable of generating radicals upon activation by light, typically consisting of one or more wavelengths comprised between 100 nm and 1500 nm. In a particular embodiment, the photoinitiator is activated by ultraviolet (UV), visible, or near infrared (IR) light, preferably UV light.

[0131] The photoinitiator of the composition of the present invention may be selected from among the known photoinitiators used in photopolymerization.

[0132] UV Photoinitiators According to one embodiment, the photoinitiator is selected from the group consisting of benzoin ethers, substituted acetophenones, derivatives of phosphine oxides, aminoketones, oxysulfonylketones, sulfonylketones, metallocenes, and azo-type compounds.

[0133] In one particular embodiment, the photoinitiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, Irgacure 819), azobisisobutyronitrile (AIBN), 4,4'-azobis(4-cyanopentanoic acid) (acide 4,4'-azobis(4-cyanopentanoique)), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959), 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (Irgacure 907), 2,2'-azobis[2-methyl-n-(2-hydroxyethyl)propionamide] (VA-086), 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651 or DMPA), (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (Darocure TPO or Lucirin TPO), lithium (2,4,6-trimethylbenzoyl)phenylphosphinate (LAP), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (Lucirin TPO-L), and mixtures thereof.

[0134] Visible Light Initiator According to another embodiment, the photoinitiator is a photosensitive system that typically consists of a combination of a first compound and a second compound that function together via a hydrogen abstraction reaction and / or electron transfer. said first compound being Weakly basic amines, preferably tertiary amines, more preferably hydroxyalkylamines, especially methyldiethanolamine, benzylamine, aniline derivatives, more particularly ethyl paradimethylaminobenzoate, N-phenylglycine, and Ascorbic Acid is selected from the group consisting of the second compound is an acridine, preferably acriflavine or acridine orange; a phenazine, preferably safranine O; an oxazine; a thiazine, preferably blue methylene or thionine; a xanthene, preferably eosin Y, rose bengal or erythrosine; a rhodamine; a thioxanthene; a polymethine; a ketocoumarin; and a thioxanthone. is selected from the group consisting of:

[0135] According to another embodiment, the photoinitiator is a photosensitive system that typically consists of a combination of a first compound and a second compound that function together by electron transfer. the first compound is selected from the group consisting of benzoin ethers, preferably 2,2-dimethoxy-2-phenylacetophenone; or substituted acetophenones, such as 2-hydroxy-2-methyl-1-phenyl-propan-1-one or 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, the second compound is selected from the group consisting of thioxanthone derivatives, preferably isopropylthioxanthone or chlorothioxanthone; and couramine or a derivative thereof.

[0136] IR (1-photon) photoinitiator Preferably, when absorption is required in the near infrared range, the photoinitiator is an organic dye, such as a polymethine, in particular a cyanine, which is preferably a carbocyanine, phthalocyanine, naphthalocyanine, and metal complexes of these dyes, such as cobalt, aluminum, copper, iron, lead, magnesium, nickel, silicon, tin, titanium, vanadium, or zinc, with counterions, such as iodide, perchlorate.

[0137] In particular, the photoinitiator may be indotricarbocyanine (HITC). The photoinitiator may be a combination of indotricarbocyanine and methyldiethanolamine.

[0138] IR (2-photon) photoinitiators In a particular embodiment, the photoinitiator is compatible with the TPS method (multiphoton technique) and exhibits a two-photon action cross section of at least 0.1 GM, preferably higher than 1 GM, advantageously higher than 100 GM. A suitable two-photon action cross section is characterized by a good two-photon absorption cross section and / or a good yield of radical production from the excited state.

[0139] In such an embodiment, the photoinitiator typically has a two-photon absorption cross-section suitable for two-photon absorption for two-photon polymerization with a wavelength comprised between 200 nm and 1500 nm, preferentially between 500 nm and 1000 nm, advantageously between 700 nm and 850 nm.

[0140] Preferably, the photoinitiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO).

[0141] The mass ratio of the photoinitiator to the first monomer M1 in the composition of the present invention may be from 1 / 1000 to 5 / 100, preferably from 1 / 1000 to 1 / 100, and more preferably from 2 / 1000 to 5 / 1000.

[0142] In one particular embodiment, the composition of the invention advantageously comprises: a first monomer M1 in an amount ranging from 40 to 98.9% by weight, preferably from 60 to 98% by weight, relative to the total weight of the composition, a mass ratio of the second monomer M2 to the first monomer M1 of 1 / 100 to 20 / 100, preferably 1 / 100 to 5 / 100, more preferably 1 / 100 to 3 / 100, for example, 1.5 / 100 to 2.5 / 100, and - a mass ratio of the photoinitiator to the first monomer M1 of 1 / 1000 to 5 / 100, preferably 1 / 1000 to 1 / 100, more preferably 2 / 1000 to 5 / 1000 Includes.

[0143] In one particular embodiment, the composition of the invention comprises: - Pentaerythritol triacrylate (PETIA), Pentaerythritol tetra-acrylate (PETEA), Propoxylated glycerin triacrylate (EB53), Glycerol triacrylate, Trimethylolethane triacrylate, Trimethylolpropane triacrylate (TMPTA or TTA), Di(trimethylolpropane)tetra-acrylate (DTMPTA), Ethylene glycol diacrylate, Diethylene glycol diacrylate, Triethylene glycol diacrylate, Polyethylene glycol diacrylate (PEGDA), Propylene glycol diacrylate, Dipropylene glycol diacrylate, Tripropylene glycol diacrylate, Polypropylene glycol diacrylate, Bisphenol A ethoxylate diacrylate (Bis-EDA), Ethylene glycol dimethacrylate, Diethylene glycol dimethacrylate, Triethylene glycol dimethacrylate (TEGDMA), Polyethylene glycol dimethacrylate, Propylene glycol dimethacrylate, Dipropylene glycol dimethacrylate , Tripropylene glycol dimethacrylate, Polypropylene glycol dimethacrylate, 2,2-bis-4-(methacryloxyethoxy)phenylpropane, Tricyclodecane dimethanol dimethacrylate, 1,10-decanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, Neopentyl glycol dimethacrylate, 2-hydroxy 1,3-dimethacryloxypropane, Trimethylolpropane trimethacrylate, Ethoxylated trimethylolpropane trimethacrylate a first monomer M1 selected from methacrylate, ditrimethylolpropane tetramethacrylate, tris(2-hydroxyethyl)isocyanurate trimethacrylate, diurethane dimethacrylate (UDMA), dipentaerythritol pentamethacrylate, ethoxylated pentaerythritol tetramethacrylate, propoxylated glyceryl trimethacrylate, propoxylated trimethylolpropane trimethacrylate, bisphenol A glycidyl methacrylate (bis-GMA), and mixtures thereof, preferably PETIA; a second monomer M2 as defined above (preferably a compound of formula (Ia) or formula (Ib), more preferably DOT), and - Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, Irgacure 819), azobisisobutyronitrile (AIBN), 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173), 2-hydroxy-4'-(2-hydroxyphenyl) photoinitiator selected from (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (Darocure TPO or Lucirin TPO), lithium (2,4,6-trimethylbenzoyl)phenylphosphinate (LAP), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (Lucirin TPO-L), and mixtures thereof, preferably BAPO. Includes.

[0144] In a more particular embodiment, the composition of the invention comprises a first monomer M1 selected from pentaerythritol triacrylate (PETIA), pentaerythritol tetra-acrylate (PETEA), propoxylated glycerin triacrylate (EB53), glycerol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate (TMPTA or TTA), di(trimethylolpropane) tetra-acrylate (DTMPTA), triethylene glycol dimethacrylate (TEGDMA), polyethylene glycol diacrylate (PEGDA), diurethane dimethacrylate (UDMA), bisphenol A glycidyl methacrylate (bis-GMA), bisphenol A ethoxylate diacrylate (bis-EDA), and mixtures thereof, preferably PETIA; a second monomer M2 as defined above (preferably a compound of formula (Ia) or formula (Ib), more preferably DOT), and - Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, Irgacure 819), azobisisobutyronitrile (AIBN), 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173), 2-hydroxy-4'-(2-hydroxyphenyl) photoinitiator selected from (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (Darocure TPO or Lucirin TPO), lithium (2,4,6-trimethylbenzoyl)phenylphosphinate (LAP), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (Lucirin TPO-L), and mixtures thereof, preferably BAPO. Includes.

[0145] In one particular embodiment, the composition of the invention comprises: - Pentaerythritol triacrylate (PETIA), Pentaerythritol tetra-acrylate (PETEA), Propoxylated glycerin triacrylate (EB53), Glycerol triacrylate, Trimethylolethane triacrylate, Trimethylolpropane triacrylate (TMPTA or TTA), Di(trimethylolpropane)tetra-acrylate (DTMPTA), Ethylene glycol diacrylate, Diethylene glycol diacrylate, Triethylene glycol diacrylate, Polyethylene glycol diacrylate (PEGDA), Propylene glycol diacrylate, Dipropylene glycol diacrylate, Tripropylene glycol diacrylate, Polypropylene glycol diacrylate, Bisphenol A ethoxylate diacrylate (Bis-EDA), Ethylene glycol dimethacrylate, Diethylene glycol dimethacrylate, Triethylene glycol dimethacrylate (TEGDMA), Polyethylene glycol dimethacrylate, Propylene glycol dimethacrylate, Dipropylene glycol dimethacrylate , Tripropylene glycol dimethacrylate, Polypropylene glycol dimethacrylate, 2,2-bis-4-(methacryloxyethoxy)phenylpropane, Tricyclodecane dimethanol dimethacrylate, 1,10-decanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, Neopentyl glycol dimethacrylate, 2-hydroxy 1,3-dimethacryloxypropane, Trimethylolpropane trimethacrylate, Ethoxylated trimethylolpropane trimethacrylate a first monomer M1 selected from methacrylate, ditrimethylolpropane tetramethacrylate, tris(2-hydroxyethyl)isocyanurate trimethacrylate, diurethane dimethacrylate (UDMA), dipentaerythritol pentamethacrylate, ethoxylated pentaerythritol tetramethacrylate, propoxylated glyceryl trimethacrylate, propoxylated trimethylolpropane trimethacrylate, bisphenol A glycidyl methacrylate (bis-GMA), and mixtures thereof, preferably PETIA; a second monomer M2, which is a compound of formula (Ia), preferably selected from the group consisting of compounds of formula (Ia''-1), (Ia''-2), (Ia''-3) or (DOT) above, and - Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, Irgacure 819), azobisisobutyronitrile (AIBN), 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173), 2-hydroxy-4'-(2-hydroxyphenyl) photoinitiator selected from (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (Darocure TPO or Lucirin TPO), lithium (2,4,6-trimethylbenzoyl)phenylphosphinate (LAP), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (Lucirin TPO-L), and mixtures thereof, preferably BAPO. Includes.

[0146] In a more particular embodiment, the composition of the invention comprises a first monomer selected from pentaerythritol triacrylate (PETIA), pentaerythritol tetra-acrylate (PETEA), propoxylated glycerin triacrylate (EB53), glycerol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate (TMPTA or TTA), di(trimethylolpropane) tetra-acrylate (DTMPTA), triethylene glycol dimethacrylate (TEGDMA), polyethylene glycol diacrylate (PEGDA), diurethane dimethacrylate (UDMA), bisphenol A glycidyl methacrylate (bis-GMA), bisphenol A ethoxylate diacrylate (bis-EDA), and mixtures thereof, preferably PETIA; a second monomer M2, which is a compound of formula (Ia), preferably selected from the group consisting of compounds of formula (Ia''-1), (Ia''-2), (Ia''-3) or (DOT) above, and - Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, Irgacure 819), azobisisobutyronitrile (AIBN), 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173), 2-hydroxy-4'-(2-hydroxyphenyl) photoinitiator selected from (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (Darocure TPO or Lucirin TPO), lithium (2,4,6-trimethylbenzoyl)phenylphosphinate (LAP), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (Lucirin TPO-L), and mixtures thereof, preferably BAPO. Includes.

[0147] In one particular embodiment, the composition of the invention comprises: - Pentaerythritol triacrylate (PETIA), Pentaerythritol tetra-acrylate (PETEA), Propoxylated glycerin triacrylate (EB53), Glycerol triacrylate, Trimethylolethane triacrylate, Trimethylolpropane triacrylate (TMPTA or TTA), Di(trimethylolpropane)tetra-acrylate (DTMPTA), Ethylene glycol diacrylate, Diethylene glycol diacrylate, Triethylene glycol diacrylate, Polyethylene glycol diacrylate (PEGDA), Propylene glycol diacrylate, Dipropylene glycol diacrylate, Tripropylene glycol diacrylate, Polypropylene glycol diacrylate, Bisphenol A ethoxylate diacrylate (Bis-EDA), Ethylene glycol dimethacrylate, Diethylene glycol dimethacrylate, Triethylene glycol dimethacrylate (TEGDMA), Polyethylene glycol dimethacrylate, Propylene glycol dimethacrylate, Dipropylene glycol dimethacrylate , Tripropylene glycol dimethacrylate, Polypropylene glycol dimethacrylate, 2,2-bis-4-(methacryloxyethoxy)phenylpropane, Tricyclodecane dimethanol dimethacrylate, 1,10-decanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, Neopentyl glycol dimethacrylate, 2-hydroxy 1,3-dimethacryloxypropane, Trimethylolpropane trimethacrylate, Ethoxylated trimethylolpropane trimethacrylate a first monomer M1 selected from methacrylate, ditrimethylolpropane tetramethacrylate, tris(2-hydroxyethyl)isocyanurate trimethacrylate, diurethane dimethacrylate (UDMA), dipentaerythritol pentamethacrylate, ethoxylated pentaerythritol tetramethacrylate, propoxylated glyceryl trimethacrylate, propoxylated trimethylolpropane trimethacrylate, bisphenol A glycidyl methacrylate (bis-GMA), and mixtures thereof, preferably PETIA; a second monomer M2 which is a compound of formula (Ib), preferably selected from the group consisting of compounds of formula (SCM1), (SCM2), (SCM3), (SCM4), (SCM5), (SCM6) or (SCM7) as defined above, more preferably selected from compounds of formula (SCM1) or (SCM2), and - Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, Irgacure 819), azobisisobutyronitrile (AIBN), 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173), 2-hydroxy-4'-(2-hydroxyphenyl) photoinitiator selected from (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (Darocure TPO or Lucirin TPO), lithium (2,4,6-trimethylbenzoyl)phenylphosphinate (LAP), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (Lucirin TPO-L), and mixtures thereof, preferably BAPO. Includes.

[0148] In a more particular embodiment, the composition of the invention comprises a first monomer M1 selected from pentaerythritol triacrylate (PETIA), pentaerythritol tetra-acrylate (PETEA), propoxylated glycerin triacrylate (EB53), glycerol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate (TMPTA or TTA), di(trimethylolpropane) tetra-acrylate (DTMPTA), triethylene glycol dimethacrylate (TEGDMA), polyethylene glycol diacrylate (PEGDA), diurethane dimethacrylate (UDMA), bisphenol A glycidyl methacrylate (bis-GMA), bisphenol A ethoxylate diacrylate (bis-EDA), and mixtures thereof, preferably PETIA; a second monomer M2 which is a compound of formula (Ib), preferably selected from the group consisting of compounds of formula (SCM1), (SCM2), (SCM3), (SCM4), (SCM5), (SCM6) or (SCM7) as defined above, more preferably selected from compounds of formula (SCM1) or (SCM2), and - Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, Irgacure 819), azobisisobutyronitrile (AIBN), 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Irgacure 1173), 2-hydroxy-4'-(2-hydroxyphenyl) photoinitiator selected from (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (Darocure TPO or Lucirin TPO), lithium (2,4,6-trimethylbenzoyl)phenylphosphinate (LAP), ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (Lucirin TPO-L), and mixtures thereof, preferably BAPO. Includes.

[0149] In a preferred embodiment, the composition of the present invention comprises - a first monomer M1, which is PETIA; a second monomer M2 which is a compound of formula (Ia) or formula (Ib), preferably DOT, and - Photoinitiator which is BAPO Includes.

[0150] In another preferred embodiment, the composition of the present invention comprises: - a first monomer M1, which is PETIA; a second monomer M2, which is preferably a compound of formula (Ia) selected from the group consisting of compounds of formula (Ia''-1), formula (Ia''-2), formula (Ia''-3) or formula (DOT) above, more preferably DOT; and - Photoinitiator which is BAPO Includes.

[0151] In another preferred embodiment, the composition of the present invention comprises: - a first monomer M1, which is PETIA; a second monomer M2 which is a compound of formula (Ib), preferably selected from the group consisting of compounds of formula (SCM1), (SCM2), (SCM3), (SCM4), (SCM5), (SCM6) or (SCM7) as defined above, more preferably selected from compounds of formula (SCM1) or (SCM2), and - Photoinitiator which is BAPO Includes.

[0152] The photoactivatable resin composition of the present invention may further comprise any suitable solvent, for example a solvent selected from among alcohols (e.g., methanol, ethanol, propanol, isopropanol), ethers, ketones (e.g., linear or cyclic ketones, e.g., acetone or cyclohexanone), alkanes (e.g., linear or cyclic alkanes, e.g., hexane or cyclohexane), and aromatic hydrocarbons (e.g., toluene). Preferably, the composition of the present invention is solvent-free.

[0153] The composition of the present invention may further include any suitable additive, particularly additives that are typically included in 3D printing resin compositions. For example, the composition of the present invention may further include one or more additives selected from light absorbers, light stabilizers, light shielding agents, inhibitors, organic or inorganic fillers (e.g., organic or inorganic nanoparticles, such as TiO2, SiO2, metal nanoparticles, etc.), surfactants, pigments, or colorants (e.g., photochromes and photoisomerization compounds).

[0154] The composition of the invention may be prepared by mixing the components contained therein in any order. The mixing step may typically be carried out at room temperature, preferably for a period comprised between 1 hour and 10 days, for example between 1 day and 5 days. In this specification, the expression "room temperature" refers to a temperature comprised between 5°C and 40°C, preferably between 15°C and 30°C. Preferably, the mixing step is carried out in the absence of light. The composition of the invention is advantageously liquid or quasi-liquid.

[0155] In one embodiment in which the monomer M1 is in prepolymer form, the preparation of the composition of the present invention may include a preliminary step of forming a prepolymer of the monomer M1 prior to the step of adding the other components (i.e., the monomer M2, the photoinitiator, and optional additives).

[0156] Degradable polymers (or equivalently, degradable resins) can be produced by irradiating the photoactivatable resin composition of the present invention. Another object of the present invention is therefore a photopolymerization method comprising a step of irradiating the photoactivatable resin composition defined herein. As mentioned above, the irradiating step is carried out by a light source (or equivalently "light radiation"), such as a laser (e.g. a continuous wave laser or a pulsed laser), a laser diode, a lamp, a DLP projector, an LCD (Liquid Crystal Display) projector, or an LED (Light Emitting Diode). The light (radiation) may consist of one or more wavelengths comprised between 100 nm and 1500 nm. Preferably, said light is ultraviolet (UV) light, visible light, or near infrared (IR) light.

[0157] In a preferred embodiment, the light source is a UV light source. Examples of UV light sources include, but are not limited to, UV lasers, UV laser diodes, UV lamps (e.g., mercury lamps or xenon lamps), DLP projectors, LCD projectors, or LEDs.

[0158] The light may be continuous light or pulsed light. The time length of the pulses of pulsed light may be on the order of microseconds, nanoseconds, or femtoseconds.

[0159] In general, the conditions of the photopolymerization method of the present invention, more specifically, the conditions of the irradiating step, may be similar to those used in known photopolymerization methods of known acrylate or methacrylate resin compositions. For example, the photopolymerization method may be carried out under the conditions of a single-photon photopolymerization method or a multi-photon (particularly two-photon) photopolymerization method. Furthermore, the apparatus for carrying out the photopolymerization method of the present invention, more specifically, the irradiating step, may be similar to those used in known photopolymerization methods of known acrylate or methacrylate resin compositions. For example, the above-mentioned light source may be applied to the resin composition of the present invention using an equipment equipped with an optical system, a galvanometer, a mask, a lens, and / or a diffraction grating.

[0160] The photopolymerization process of the present invention produces polymers (or equivalently, resins) that are degradable. Another object of the present invention are the degradable polymers obtainable by the photopolymerization process of the present invention.

[0161] Another object of the present invention is a degradable polymer based on the photoactivatable resin composition defined herein.

[0162] In this specification, "polymer based on photoactivatable resin composition" refers to a polymer that includes (preferably consists of) the reaction products of each component of the composition that is involved in photopolymerization. The components that are involved in photopolymerization are compounds that react with each other to form polymer chains and / or polymer networks during photopolymerization. In the composition of the present invention, such components typically include the first and second monomers and the photoinitiator. The polymer may also be a mixture with components that are not involved in photopolymerization, such as additives, residual monomers, residual photoinitiators, or any by-products. The polymer of the present invention may be based on a composition of the present invention comprising a first monomer in an amount of 40 to 98.9% by mass, preferably 60 to 98% by mass, based on the total mass of the composition, a mass ratio of the second monomer M2 to the first monomer M1 of 1 / 100 to 20 / 100, preferably 1 / 100 to 5 / 100, more preferably 1 / 100 to 3 / 100, for example 1.5 / 100 to 2.5 / 100, and a mass ratio of the photoinitiator to the first monomer M1 of 1 / 1000 to 5 / 100, preferably 1 / 1000 to 1 / 100, more preferably 2 / 1000 to 5 / 1000.

[0163] The polymers based on the photoactivatable composition of the invention or obtained by the photopolymerization method of the invention are degradable and may be biodegradable. To obtain the degradation, mild conditions can be applied to the polymer. For example, the polymers can be degraded by using a basic solution. The basic solution can comprise one or more bases (e.g. hydroxides such as sodium hydroxide or potassium hydroxide) in solution or suspension in a solvent (e.g. water, alcohol, e.g. methanol or ethanol, acetonitrile, acetone, diethyl ether, tetrahydrofuran, toluene, dimethyl sulfoxide, or mixtures thereof), e.g. KOH in methanol, water, tetrahydrofuran, or mixtures thereof. Alternatively, the polymers can be composted. The degradation can be carried out at room temperature or advantageously accelerated by heating at temperatures comprised between 30° C. and 150° C. Depending on the conditions and the size of the sample to be degraded, the degradation of the polymer can take place over a few seconds, minutes, hours, or days. For example, the degradation of a micrometer sample can take place over a few seconds, and a few cm. 3 Decomposition of the object may occur over a period of minutes or hours.

[0164] Another object of the present invention is a method for three-dimensionally (3D) printing a degradable 3D printed article, comprising irradiating a light-activated resin composition as defined herein under conditions that allow the formation of a 3D printed article.

[0165] As used herein, the term "3D printing" refers to the fabrication of any 3D molded article of any size by curing a liquid or quasi-liquid resin composition. 3D printing of molded articles having a thin thickness (e.g., micron size (i.e., micron range size, typically 1 μm to 100 μm) or millimeter size (i.e., millimeter range size, typically 1 mm to 100 mm)) and a constant thickness may also be referred to as "2.5D printing" herein. 3D printing of molded articles having a micron size (i.e., micron range size, typically 1 μm to 100 μm) may also be referred to as "3D-microfabrication" herein.

[0166] The irradiating step of the 3D printing method of the present invention is performed by a light source (or equivalently "light radiation"), such as a laser (e.g., continuous wave laser or pulsed laser), a laser diode, a lamp, a DLP projector, an LCD projector, or an LED. The light (radiation) may consist of one or more wavelengths comprised between 100 nm and 1500 nm. Preferably, said light is ultraviolet (UV) light, visible light, or near infrared (IR) light.

[0167] In a preferred embodiment, the light source is a UV light source. Examples of UV light sources include, but are not limited to, UV lasers, UV laser diodes, UV lamps (e.g., mercury lamps or xenon lamps), DLP projectors, LCD projectors, or LEDs.

[0168] The light source may be continuous light or pulsed light. The time length of the pulses of the pulsed light may be on the order of microseconds, nanoseconds, or femtoseconds.

[0169] The conditions of the 3D printing method may be similar to those used in known 3D printing methods using known acrylate or methacrylate resin compositions. Furthermore, the 3D printer, more generally, the 3D printing method of the present invention, and more specifically, the equipment for carrying out the irradiating step, may be similar to the equipment used in known 3D printing methods using known acrylate or methacrylate resin compositions. For example, the aforementioned light source can be applied to the resin composition of the present invention using equipment equipped with optics, reflective galvanometers, masks, lenses, and / or diffraction gratings. Furthermore, the 3D printing can be carried out, in particular, by the use of a computer to define the 3D structure of the molded article to be printed.

[0170] In one particular embodiment, the 3D printing method of the present invention is carried out in a vat.

[0171] In a more detailed embodiment, the 3D printing method is performed by a 3D printer comprising a vat, a light source as defined above, an elevator, and a build platform.

[0172] In some embodiments, the 3D printing method is performed layer-by-layer. In such embodiments, the 3D printing method preferably comprises: (i) providing a layer of a photoactivatable resin composition as defined herein; (ii) irradiating the layer of step (i) so as to obtain a cured photoactivatable resin layer; Including, Steps (i) and (ii) are repeated cyclically to obtain a build-up of cured layers that form the 3D printed part.

[0173] More particularly, the 3D printing method may be carried out by stereolithography (or "SLA"), for example two-photon or multi-photon stereolithography. In stereolithographic 3D printing methods, the irradiating step is typically carried out using a laser, more particularly a UV laser.

[0174] Alternatively, 3D printing may be performed by Digital Light Processing (or "DLP"). In such embodiments, the illuminating step is typically performed using a DLP projector.

[0175] Alternatively, 3D printing may be performed by daylight polymer printing (or "DPP"). In such an embodiment, the illuminating step is typically performed using an LCD projector.

[0176] In some other embodiments, the 3D printing method is performed continuously (i.e., not layer-by-layer). More particularly, the 3D printing method may be performed by continuous liquid interface manufacturing (or "CLIP"). In such embodiments, the irradiating step is typically performed using UV light.

[0177] Another object of the invention is a degradable 3D printed article based on (or containing or consisting of) the degradable polymer of the invention. Another object of the invention is a degradable 3D printed article obtained by the 3D printing method of the invention.

[0178] The 3D printed molded article can be degradable and biodegradable. To obtain degradation, mild conditions can be applied to the molded article. Examples of degradation conditions are those described above for the degradable polymers of the present invention.

[0179] The present invention also relates to the use of a monomer comprising a cyclic methacrylate of a thionolactone or sulfide (e.g., a compound of formula (Ia) or formula (Ib)) as defined herein for the manufacture of a degradable 3D printed article as defined herein.

[0180] The present invention also relates to the use of a monomer comprising a cyclic methacrylate of a thionolactone or sulfide (e.g., a compound of formula (Ia) or formula (Ib)) as defined herein for the manufacture of a photoactivatable resin composition suitable for 3D printing.

[0181] The present invention also relates to the use of a monomer comprising a cyclic methacrylate of a thionolactone or sulfide (e.g., a compound of formula (Ia) or formula (Ib)) as defined herein for the preparation of a photoactivatable resin composition suitable for 3D printing degradable molded articles.

[0182] Another object of the invention is the compounds of formula (Ia''-1) or formula (Ia''-2) or formula (Ia''-3) below:

[0183] [ka]

[0184] The present invention is also described in further detail in the following examples, which do not limit the scope of the invention, which is defined by the appended claims. EXAMPLES

[0185] Materials and Methods All reagents were used as received. Pentaerythritol triacrylate, isopropylamine, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), ammonia (4% in MeOH, 2.0 mol / L) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and SPLINT resin were commercially available. Dibenzo[c,e]-oxepane-5-thione (DOT) was synthesized according to literature procedures (Bingham et al., Chem. Commun. 2019, 55, 55-58). 2-Methylene-1,3-dioxepane (MDO) was synthesized according to literature procedures (Bailey et al., J. Polym. Sci. Part A Polym. Chem. 1982, 20, 3021-3030).

[0186] FDM of the polypropylene molds was performed on an Ultimaker2+ manufactured by Ultimaker. G-code print files were generated using Cura software. Polypropylene filament was purchased from Ultimaker. The nozzle temperature was set at 230°C and the bed temperature was set at 100°C. All layers were printed at 100% speed without fan cooling. The bed was heated at 100°C for 30 minutes before printing. Pre-photopolymerization in the polypropylene molds (PP molds) was performed for 30 seconds for all samples using a Hamamatsu Photonics LC-L5 lamp at 365 nm.

[0187] 1 H NMR spectra were measured on a Bruker AC400 (400 MHz) spectrometer or a Bruker AC300 (300 MHz) spectrometer at 298 K (20 °C). Data are reported as follows: chemical shift (ppm) referenced to the internal solvent signal (peak at 7.26 ppm for CDCl3), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, quint = quintet, dd = complex doublet, m = multiplet, bs = broad line, app = apparent) and coupling constant (Hz). 13 C{ 1 H}NMR spectra were measured on a Bruker AC400 (100 MHz) spectrometer or a Bruker AC300 (75 MHz) spectrometer with full proton decoupling. Chemical shifts were reported in ppm from the internal solvent signal (peak at 77.16 ppm for CDCl3 and 53.84 for CD2Cl2). Experiments were performed on a commercial Bruker double-bearing probe containing a zirconium dioxide rotor with an outer diameter of 4 mm. For cross-polarization (CP) MAS experiments, typical parameters were a contact time of 5 ms, a recycle delay of 5 s, 8192 scans, and a spin speed of 10 kHz. Gradient 1H pulses were used to avoid the Hartman-Hahn mismatch (OB Peersen, X. Wu, I. Kustanovich, SO Smith, J. Magn. Reson. 1993, 104, 334-339). To improve the resolution, a dipolar decoupled TPPM-15 pulse sequence was applied during the acquisition time. Experiments were carried out at room temperature. Chemical shifts were referenced to tetramethylsilane, whose resonance was set to 0 ppm.

[0188] The product was purified by flash column chromatography on silica gel 60 (Macherey-Nagel® Si60, 0.040-0.063 mm).

[0189] A UV laser diode emitting at 375 nm is introduced into a single-mode optical fiber (Corining SMF-28e, core φ: 8 μm) using an objective lens with a numerical aperture of 0.4. 3D printing is performed by capturing 2980 × 1080 pixel images (λ irr =365nm, irradiance=10mW.cm -2 The experiment was carried out using a DLP projector (Ikarus Full-HD DLP6500 light engine module manufactured by Invision) that allows the projection of a wide variety of images.

[0190] The PP molds were printed on an Ultimaker2+ manufactured by Ultimaker. G-code print files were generated using Cura software (spftware). Polypropylene filament was purchased from Ultimaker. The nozzle temperature was set at 230°C and the bed temperature was set at 100°C. All layers were printed at 100% speed with no fan cooling. The bed was heated at 100°C for 30 minutes prior to printing.

[0191] Synthesis of compound (Ia''-2=POT)

[0192] [ka]

[0193] - Synthesis of 2

[0194] [ka]

[0195] 2 was synthesized according to the procedure described in Chem. Soc. 2013, 19, 2606.

[0196] To a solution of 1 (0.2 M in DCM, 3.0 g, 17.2 mmol, 1.0 equiv) was added mCPBA (7.1 g, 41.3 mmol, 2.4 equiv) at 0 °C. After stirring at room temperature for 12 h, the reaction mixture was quenched with 10% K2CO3 solution and a saturated aqueous solution of Na2S2O3. The aqueous layer was separated and extracted with dichloromethane. The combined organic layers were dried over MgSO4, filtered, and concentrated under vacuum. The resulting product was purified by flash chromatography on silica gel using 10-30% EtOAc in pentane as eluent to afford 2 (3.1 g, 93%) as a white solid. 1 H NMR (400 MHz, chloroform-d) δ 7.36 - 7.20 (m, 5H), 5.22 (d, J = 9.3 Hz, 1H), 2.69 (m, 2H), 2.11 - 1.88 (m, 4H), 1.76 - 1.57 (m, 2H).

[0197] - Synthesis of (Ia''-2)

[0198] [ka]

[0199] A mixture of 2 (0.5 g, 9.64 mmol, 1.0 equiv) and Lawesson's reagent (0.88 g, 2.18 mmol, 0.6 equiv) was dissolved in anhydrous toluene under inert atmosphere. The suspension was refluxed for 6 h. After cooling to room temperature, the solution was concentrated by half and filtered through a plug of silica gel. The filtrate was concentrated under vacuum. The crude product was purified by flash chromatography on silica gel using 20% ​​EtOAc in pentane as eluent to afford compound (Ia''-2) (2.3 g, 53%) as a dark oil. 1 H NMR (400 MHz, chloroform-d) δ 7.53 - 7.31 (m, 5H), 5.66 - 5.49 (d, J = 9.3 Hz, 1H), 3.61 (m, 1H), 3.08 (m, 1H), 2.17 - 2.05 (m, 4H), 1.94 - 1.67 (m, 2H).

[0200] Synthesis of 6-methylene-1,4-oxathiepane-7-one compound (=M4=compound SCM1) Adapted from J. Am. Chem. Soc. 2009, 131, 9805.

[0201] [ka]

[0202] - Synthesis of 4

[0203] [ka]

[0204] 4 was synthesized according to the following procedure: Triethylamine (5.18 mL, 37.3 mmol, 2.0 equiv) was added dropwise to a cooled (0° C.) solution of R-bromomethylacrylic acid (3) (3.07 g, 18.6 mmol, 1.0 equiv) in dichloromethane (100 mL). 6-mercapto-1-hexanol (2.50 g, 18.6 mmol, 1.0 equiv) was then added over 15 min and the reaction mixture was stirred for 20 h. A solution of ammonium sulfate (9.0 g, 78.8 mmol, 4.2 equiv) and sulfuric acid (5 mL, 2 M, 10 mmol) in water (100 mL) was cooled to 0° C. and the reaction mixture was poured into it. This mixture was extracted with diethyl ether (3×60 mL). The combined organic layers were dried over magnesium sulfate and concentrated under vacuum to give 4 (3.72 g, 92%) as a white solid. 1 H NMR (400 MHz, chloroform-d) δ 6.80 - 6.67 (m, 1H), 6.23 (s, 1H), 4.71 (d, J = 6.0 Hz, 2H), 4.35 (s, 2H), 3.63 (t, J = 6.0 Hz, 2H).

[0205] - Synthesis of M4 (=compound SCM1)

[0206] [ka]

[0207] M4 was synthesized according to the following procedure: 4 (1.5 g, 6.87 mmol, 1.0 equiv) was dissolved in a mixture of dichloromethane (60 mL) and triethylamine (7.6 mL, 55.0 mmol, 8.0 equiv) and added via syringe pump over 8 h to a refluxing solution of 2-chloro-1-methylpyridinium chloride (7.0 g, 27.5 mmol, 4.0 equiv) in dichloromethane (650 mL). The reaction mixture was cooled to room temperature and filtered. The solvent was evaporated under vacuum and the crude product was dissolved in water (100 mL) and extracted with diethyl ether (3×30 mL). The combined organic layers were dried over magnesium sulfate and the solvent was evaporated to give an orange liquid. The crude product was purified by flash column chromatography using dichloromethane as eluent to give M4 as a pale yellow solid (410 mg, 30%). 1 H NMR (400 MHz, chloroform-d) δ 5.84 (s, 1H), 5.59 (t, J = 1.3 Hz, 1H), 4.55 - 4.44 (m, 2H), 3.36 (d, J = 1.2 Hz, 2H), 2.99 - 2.90 (m, 2H).

[0208] Example 1 Preparation of the Resin Composition of the Present Invention General procedure for "DOT-PETIA resin": 2% by weight of DOT and 0.2% by weight of BAPO photoinitiator were mixed with triacrylate PETIA. The mixture was stirred at room temperature away from light for 3 days.

[0209] For PETIA resin (comparative resin): 0.2 wt % BAPO photoinitiator was mixed with triacrylate PETIA. The mixture was stirred at room temperature away from light for 3 days.

[0210] Example 2 FTIR characterization and mechanical properties of the polymers of the present invention Photopolymerization was monitored in situ by real-time Fourier transform infrared spectroscopy using a Thermo-Nicolet 6700IR spectrometer. KBr pellets were used as substrates and a thin polypropylene film was used to avoid atmospheric interactions. Irradiation was performed in situ using a 100 W mercury-xenon lamp (Hamamatsu LC9588 / 02A) with a bandpass filter centered at 365 nm (Hamamatsu A9616-07). The conversion was measured at 1635 cm -1 Calculated from the reduction in bands.

[0211] The photopolymerization kinetics obtained by FTIR are plotted in FIG. 1. They are based on monitoring the C=C conversion of the acrylate functional groups in the monomer. At a BAPO concentration of 0.5 wt.%, the polymerization is efficient, leading to a final conversion rate of more than 60%, and the conversion equilibrium is reached quickly. This type of kinetics is typical for such triacrylate monomers. The trifunctional character ensures a very fast initial polymerization rate, and the rapid increase in viscosity leads to considerable gelation of the medium, which stops the polymerization and prevents higher conversions. The addition of DOT (2 wt.%) slightly reduces the effectiveness of the photopolymerization, both in terms of initial rate and final conversion rate (50%), but still keeps it generally compatible with the 3D printing method. In particular, it can be seen that it is possible to reduce the BAPO concentration to 0.2 wt.%, while maintaining an effective polymerization, including sufficient crosslinking of the polymer to give the material interesting mechanical properties, quantitatively observed after irradiation.

[0212] Mechanical testing was performed using an INSTRON 4505 dynamometer modernized ZWICK / ROELL (TestXpert II software). As shown in Table 1, the addition of DOT slightly modifies the mechanical properties of the polymer by resulting in a slightly softer, less brittle polymer. Young's modulus, tensile strength, and elongation values ​​remain of the same order of magnitude.

[0213] [Table 1]

[0214] Example 3 3D manufacturing using the resin composition of the present invention 1) Microstructuring in optical fibers Laser microstructuring configurations were used to demonstrate the potential of the polymers of the invention for use in laser-induced 3D microfabrication.

[0215] A UV laser diode emitting at 375 nm is introduced into a single-mode optical fiber (Corning SMF-28e, core φ: 8 μm) using an objective lens with a numerical aperture of 0.4. A drop of resin is placed vertically on the other side of the fiber. Capillary action ensures the formation of a quasi-hemispherical drop with a radius of about 50 μm. Microchips are then photogenerated by irradiation with a power between 1 μW and 10 μW at the surface of the fiber. After rinsing by immersion in ethanol for a few seconds, microchips are obtained on the optical fiber.

[0216] 2)3D printing Two different setups are used in 3D printing: For DLP printing, the inventors print a 2980×1080 pixel image (λ irr =365nm, irradiance=10mW cm -2 A DLP projector (Ikarus Full-HD DLP6500 light engine module from Invision) was used, which allows projecting 3D images of the 3D structures. The resin was cast into a reservoir and covered with a microscope slide. After exposure, unreacted resin was removed by washing with ethanol. 2.5D samples can be fabricated using this setup.

[0217] 3D printing was performed on a Miicraft 125 series printer using a layer thickness of 50 μm (385 nm UV-LED, 1 second exposure time per layer, 7 seconds exposure time for the first layer, 4 buffer layers, 80% powerful). A mii code print file was generated using utility software.

[0218] Using both setups, various objects have been fabricated in various geometries, making it interesting to build 2.5D and 3D objects with arbitrary shapes, as shown in Figure 2. Although some yellow coloring can be seen remaining, each part keeps its transparency. For relatively thin objects, the coloring may fade after bleaching.

[0219] Example 4 Decomposition test All degradation tests were carried out at room temperature without stirring. The mouldings were immersed in THF and in the same volume of a 5 wt % solution of KOH in MeOH.

[0220] - The chip was decomposed by immersing the end of the optical fiber in the decomposition solution. Figure 3 shows that without DOT, the microchip remains attached to the end of the optical fiber after 15 minutes, whereas with DOT in the resin, the chip (rip) is decomposed after only 5 seconds. As shown in Figure 4, various decomposition solutions were tested: 5% by weight KOH in MeOH / THF 1:1 (v / v), 5% by weight KOH in MeOH, and 5% by weight KOH in water. The best results were obtained with 5% by weight KOH in MeOH / THF 1:1 (v / v).

[0221] - DLP prints were immersed in a digestion solution: 5 wt% KOH in MeOH / THF 1:1 (v / v) for multiple lengths of time.

[0222] Figure 5 demonstrates the massive decomposition of the material. A Dali mask is a macroscopic print made by DLP-UV. The print is immersed in the decomposition solution. After 17 hours, the print is removed from the solution and placed on a substrate to be photographed. It can be easily noticed that the decomposition of the print has already started. After 24 hours, this decomposition becomes even more pronounced and finer, and after 90 hours, no print can be seen in the solution anymore. This result therefore clearly confirms the role of DOT in the decomposition mechanism.

[0223] - Tablets: Small tablets on the cm scale were produced using pre-printed polypropylene moulds by FDM. The mass and appearance of these tablets were monitored during the degradation process. The use of 5% by weight KOH in MeOH / THF led to complete dissolution of the pellets in one week, while the reference pellets did not degrade even after 3 months.

[0224] To accelerate the decomposition, the KOH concentration and / or temperature were increased. Using the following decomposition conditions: 120 °C, 10 wt % KOH in MeOH / THF, 24 h, complete dissolution of this dense cm-scale feature could be obtained in 17 h.

[0225] - 3D printing: The same solution was used each time (Figure 6 top, Figures 7 and 8). More specifically, a solution of 5 wt% KOH in MeOH was used with the same volume of THF at room temperature without stirring to dissolve the 3D model. - 8 hours for the hollow cube - 24 hours around the Eiffel Tower - 1 hour on stacked dice

[0226] Homemade compost decomposition: A 400 L volume composter manufactured by EDC was used for these experiments. Decomposition was carried out in the south of France in spring 2021. Every 2 days, household waste (peelings, fruits, vegetables, fresh and dried herbs, and water) was added and the compost was stirred regularly. Hollow cubes were observed during the addition of organic matter and decomposition was monitored visually (Figure 6, bottom). After 20 days in the compost, the DOT / PETIA cubes were almost completely decomposed, while the cubes made with PETIA without DOT remained unchanged.

[0227] Example 5 Combining 3D printing and disassembly The decomposition ability of the PETIA / DOT polymer combined with the stability of PETIA makes it conceivable to use the same DLP-UV printer to fabricate objects with degradable and non-degradable parts. This possibility is demonstrated in FIG. 9. In this example, the strategy is as follows: in a first step, the objects (ghost and ball) are made with non-degradable PETIA / BAPO resin. The objects are placed in a degradable resin containing 2% by weight of DOT and a second pattern is printed (the shape of Pac-Man). Finally, the object is the head of Pac-Man in which the object is included. This matrix is ​​soluble in a solution of 5% by weight of KOH in MeOH / THF and its dissolution releases the included objects, which are not decomposed within the time required for the degradable matrix to disappear.

[0228] Example 6 Polymerization Research - Polymerization in PP molds experiment The resin composition was prepared as in Example 1. - Formulation DOT = PETIA (97.8 wt%), BAPO (0.2 wt%), DOT (2 wt%) - The resin was stirred until all the compounds were solubilized.

[0229] The resin was then cast into a polypropylene mold (PP mold) and photopolymerization was carried out for a given time and power using a Hamamatsu Photonics 365 nm LC-L5 lamp (see section "Materials and Methods" above).

[0230] Decomposition The pellets obtained after photopolymerization were refluxed in KOH (10 wt%) in MeOH / THF (1 / 1) until complete solubilization (4 h).

[0231] The solution was filtered and the filtrate was neutralized with HCl (10%) until pH was about 7. It was extracted with dichloromethane and concentrated under vacuum.

[0232] recycling The decomposition residue obtained after concentration was mixed with BAPO (1 wt%) and PETIA (30 wt%) until completely solubilized. The solution mixture was cast into a PP mold and photopolymerized at 1200 mV for 30 seconds. A solid was obtained after photopolymerization.

[0233] - DLP polymerization experiment The resin composition was prepared as in Example 1. - Formulation DOT = PETIA (97.8 wt%), BAPO (0.2 wt%), DOT (2 wt%) - The resin was stirred until all the compounds were solubilized. - Formulation (1a''-2) = PETIA (91.8% by weight), BAPO (0.2% by weight), compound (1a''-2) (8% by weight) - The resin was stirred until all the compounds were solubilized. - Formulation SCM1 (M4) (4 wt%): PETIA (95.8 wt%), BAPO (0.2 wt%), SCM1 (4 wt%) - The resin was stirred until all the compounds were solubilized. Formulation SCM1 (M4) (8% by weight): PETIA (91.8% by weight), BAPO (0.2% by weight), SCM1 (8% by weight) - the resin was stirred until all the compounds were solubilized.

[0234] The resin was cast between two optical fibers (φ=250 μm) and covered by a microscope slide. After exposure, the DLP prints were rinsed with ethanol to remove unreacted resin (see experiment in Example 3).

[0235] Decomposition was carried out by submerging the shapes in a solution of KOH (5% by weight) in MeOH / THF 1 / 1 at room temperature without stirring until complete dissolution (see experimental example 4).

[0236] result

[0237] [Table 2]

Claims

1. 1. A photoactivatable resin composition comprising: - a first monomer (M1) comprising at least two functional groups independently selected from an acrylate functional group and a methacrylate functional group; - a second monomer (M2) which is a cyclic monomer capable of undergoing radical ring opening and which comprises a moiety selected from the group consisting of thiocarbonyl-oxy, carbonyl-oxy, carbonyl-thio, disulfide, silyl ether, and acetal, and wherein the polymerization rate of M2 is comparable to or faster than the polymerization rate of M1; - Photoinitiator and 1. A photoactivatable resin composition comprising:

2. 2. The photoactivatable resin composition of claim 1, wherein the second monomer M2 comprises a thiocarbonyl-oxy moiety.

3. 2. The photoactivatable resin composition of claim 1, wherein the second monomer M2 comprises a moiety selected from the group consisting of carbonyl-oxy and carbonyl-thio.

4. 4. The photoactivatable resin composition of claim 1, wherein the second monomer M2 comprises a cyclic methacrylate of a thionolactone or a sulfide.

5. 5. The photoactivatable resin composition according to claim 1, wherein the second monomer M2 is represented by the following formula (Ia): 【Chemistry 1】 (In the formula, - m is 0, 1, 2 or 3; - n is between 0 and (2m+5); - R 1 are each independently hydrogen, halogen, or C 1 ~C 6 Alkyl, C 2 ~C 6 Alkenyl, C 2 ~C 6 Alkynyl, C 1 ~C 6 Heteroalkyl, C 3 ~C 12 Cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cyano, nitro, -C(O)OH, -C(O)H, -OH, -SH, C 1 ~C 6 selected from the group consisting of perfluoroalkyl, ester, ketone, sulfonyl, and amide; - R 2 is hydrogen, halogen, C 1 ~C 6 Alkyl, C 2 ~C 6 Alkenyl, C 2 ~C 6 Alkynyl, C 1 ~C 6 Heteroalkyl, C 3 ~C 12 Cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cyano, nitro, -C(O)OH, -C(O)H, -OH, -SH, C 1 ~C 6 selected from the group consisting of perfluoroalkyl, ester, ketone, sulfonyl, and amide; or two adjacent R 1 , or adjacent R 1 and R 2 together with the carbon atom to which they are attached, 3 ~C 12 (capable of forming a carbocyclic ring)

6. The second monomer is 【Chemistry 2】 6. The photoactivatable resin composition according to claim 1, selected from the group consisting of:

7. 7. The photoactivatable resin composition according to claim 1, wherein the second monomer is represented by the following formula (DOT): 【Chemistry 3】

8. 2. The photoactivatable resin composition according to claim 1, wherein the second monomer is represented by the following formula (Ib): 【Chemistry 4】 (In the formula, - X is O or S; - L represents an alkylene chain having k carbon atoms, optionally interrupted by one or more groups independently selected from -C(O)O- and -SS-; - k is 1 to 11; - p is between 0 and (2k+2); - R 3 are each independently hydrogen, halogen, or C 1 ~C 6 Alkyl, C 2 ~C 6 Alkenyl, C 2 ~C 6 Alkynyl, C 1 ~C 6 Heteroalkyl, C 3 ~C 12 Cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cyano, nitro, -C(O)OH, -C(O)H, -OH, -SH, C 1 ~C 6 selected from the group consisting of perfluoroalkyl, ester, ketone, sulfonyl, and amide; or two adjacent R 3 together with the carbon atom to which they are attached, 3 ~C 12 (capable of forming a carbocyclic ring)

9. The second monomer is 【Chemistry 5】 9. The photoactivatable resin composition of claim 8, selected from the group consisting of:

10. 10. The photoactivatable resin composition according to any one of claims 1 to 9, wherein the mass ratio of the second monomer M2 to the first monomer M1 is from 1 / 100 to 20 / 100, preferably from 1 / 100 to 5 / 100, more preferably from 1 / 100 to 3 / 100, even more preferably from 1.5 / 100 to 2.5 / 100.

11. 11. The photoactivatable resin composition of claim 1, wherein the first monomer is selected from pentaerythritol triacrylate (PETIA), pentaerythritol tetra-acrylate (PETEA), propoxylated glycerin triacrylate (EB53), glycerol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate (TMPTA or TTA), di(trimethylolpropane)tetra-acrylate (DTMPTA), triethylene glycol dimethacrylate (TEGDMA), polyethylene glycol diacrylate (PEGDA), diurethane dimethacrylate (UDMA), bisphenol A glycidyl methacrylate (bis-GMA), bisphenol A ethoxylate diacrylate (bis-EDA), and mixtures thereof.

12. 9. The photoactivatable resin composition of claim 1, wherein the first monomer is pentaerythritol triacrylate (PETIA).

13. The photoinitiator may be phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, azobisisobutyronitrile, 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), tert-butyl peroxide, benzoyl peroxide, benzophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, 2,2 13. The photoactivatable resin composition according to any one of claims 1 to 12, wherein the phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide is selected from phenylbis[2-methyl-n-(2-hydroxyethyl)propionamide], 2,2-dimethoxy-2-phenylacetophenone, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, lithium (2,4,6-trimethylbenzoyl)phenylphosphinate, ethyl (2,4,6-trimethylbenzoyl)phenylphosphineate, and mixtures thereof, preferably phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

14. 14. The photoactivatable resin composition according to any one of claims 1 to 13, wherein the mass ratio of photoinitiator to first monomer M1 is from 1 / 1000 to 5 / 100, preferably from 1 / 1000 to 1 / 100, more preferably from 2 / 1000 to 5 / 1000.

15. A degradable polymer based on a photoactivatable resin composition according to any one of claims 1 to 14.

16. 15. A method of photopolymerization comprising the step of irradiating the photoactivatable resin composition according to any one of claims 1 to 14.

17. 17. The photopolymerization method according to claim 16, wherein the irradiating step is carried out by a UV light source, such as a UV laser, a UV lamp (e.g., a mercury lamp or a xenon lamp), a DLP projector, an LCD projector, or an LED.

18. 15. A method for 3D printing a degradable molded article, comprising the step of irradiating a light-activatable resin composition according to any one of claims 1 to 14 under conditions that allow the formation of a 3D molded article.

19. The process is as follows: (i) providing a layer of the photoactivatable resin composition according to any one of claims 1 to 14; (ii) irradiating the layer of step (i) so as to obtain a cured photoactivatable resin layer; Including, Steps (i) and (ii) are repeated cyclically to obtain a build-up of cured layers forming a 3D printed part; The method of claim 18.

20. 20. The method of 3D printing according to claim 18 or 19, wherein the irradiating step is carried out by a UV light source, such as a laser, a UV lamp (e.g. a mercury lamp or a xenon lamp), a projector, an LCD projector, or an LED.

21. 21. A method for 3D printing according to any one of claims 18 to 20, carried out in a vat.

22. A degradable 3D printed molded article based on the degradable polymer of claim 15.

23. Use of a monomer comprising a cyclic methacrylate of a thionolactone or sulfide as defined in any one of claims 4 to 9 for producing a degradable 3D printed article as defined in claim 22.

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