Copolymers comprising thioester bonds

Abstract

The present invention relates to a method of synthesizing a copolymer comprising the step of polymerizing a monomer mixture comprising a cyclic comonomer selected from the list comprising lactones, lactams, cyclic amines, cyclic esters or mixtures thereof; and, a compound according to structure I: wherein, R 1 is hydrogen or an alkyl group having 1 to 6 carbon atoms; and, wherein, R 2 and R 3 are each independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, cycloalkenyl group; or, wherein, R 2 and R 3 together with the atoms to which they are attached form a saturated or unsaturated 3-, 4-, 5-, 6- or 7-membered ring which can be substituted. The present invention further relates to a copolymer obtained from said method and to the use of a compound according to structure (I) for accelerating biodegradability. (I)

Description

Technical Field

[0001] This invention relates to (bio)degradable polymers and copolymers, and methods for preparing them. More particularly, this invention relates to improving the biodegradability of polymers while maintaining ease of production. In a particular embodiment, the invention can provide an indication of the state of biodegradability of the polymer. Background Technology

[0002] Aliphatic polyesters (PEs) are a class of interesting chemically recyclable or non-permanent polymers. Some are bio-based and sometimes even fully biodegradable due to the susceptibility of their ester bonds to chemical and / or enzymatic hydrolysis. One of the most prominent polyesters is poly(lactic acid) (PLA). Although PLA is considered biodegradable, its degradation is only fast enough under industrial composting conditions. Commercially available PLA is currently synthesized via ring-opening polymerization (ROP) of dilactone, lactide (LD), which is prepared via a backbiting degradation method of polycondensed lactic acid (LA), a time-consuming and energy-intensive process.

[0003] Although PLA and its degradation characteristics have been extensively studied, research on its sulfur-containing counterpart, poly(thiolactic acid) (PTLA), is still in its early stages. Polythioesters (PTEs, such as PTLA) are very new in the field of polymer research, but show promising potential as a class of potentially sustainable materials in the context of biodegradation and / or chemical recycling.

[0004] Similar to PLA, PTLA can be synthesized either through the polycondensation of thiolactic acid (TLA) or via the ring-opening polymerization of dithiolactide (DTL), a sulfur-containing analog of LD. However, there are currently few known synthetic routes for DTL, and existing routes either require the pyrolysis of the PTLA polymer or use recently disclosed synthetic routes that require complex and toxic reagents and waste products (Suzuki et al. 2021 and Wang et al. 2021). As a result, the polymerization of DTL or its variants has not been extensively studied.

[0005] Therefore, one of the objectives of this invention is to overcome or improve one or more of the aforementioned disadvantages existing in the market, or to meet any of the existing market demands. Preferably, this invention provides a solution that can be easily implemented in existing production facilities and methods. Summary of the Invention

[0006] The inventors have now surprisingly discovered that thiodioxolane can be used as a monomer in copolymerization reactions with other cyclic monomers, preferably selected from the list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof. The resulting copolymers are biodegradable more rapidly than polymers derived solely from other cyclic monomers.

[0007] This invention provides a method for synthesizing copolymers, comprising the step of ring-opening polymerization of a monomer mixture, the monomer mixture comprising:

[0008] - Cyclic comonomers selected from the list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and,

[0009] - Based on compounds with structure I:

[0010] (I),

[0011] Among them, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 An alkyl group having 1 to 6 carbon atoms; and,

[0012] Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0013] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0014] In some implementation schemes, R 1 It is a methyl or ethyl group, preferably wherein R 1 It is a methyl group; and / or, wherein R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0015] In some embodiments, the monomer mixture comprises:

[0016] - At least 30.0% by weight and up to 99.5% by weight of cyclic comonomers selected from a list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof, and,

[0017] - At least 0.50% by weight and up to 70.0% by weight of the compound according to structure I.

[0018] In some embodiments, the monomer mixture comprises:

[0019] - At least 30.0 wt% to at most 99.0 wt%, preferably at least 40.0 wt% to at most 98.0 wt%, preferably at least 45.0 wt% to at most 97.0 wt%, preferably at least 50.0 wt% to at most 95.0 wt%, preferably at least 60.0 wt% to at most 90.0 wt%, preferably at least 70.0 wt% to at most 85.0 wt% of cyclic comonomers, said cyclic comonomers being selected from the list comprising lactones, lactams, cyclic amines, cyclic esters or mixtures thereof; and,

[0020] - At least 1.0 wt% to at most 70.0 wt%, preferably at least 2.0 wt% to at most 60.0 wt%, preferably at least 3.0 wt% to at most 55.0 wt%, preferably at least 5.0 wt% to at most 50.0 wt%, preferably at least 10.0 wt% to at most 40.0 wt%, preferably at least 15.0 wt% to at most 30.0 wt% of the compound according to structure 1.

[0021] In some implementations, the cyclic comonomer contains 5- to 7-membered heterocycles.

[0022] In some embodiments, the cyclic comonomer is a lactone or lactam; preferably lactide, caprolactone, or caprolactam.

[0023] In some embodiments, the monomer mixture is contacted with an initiator and / or a catalyst.

[0024] In some embodiments, the method includes a step of depressurizing the formed copolymer.

[0025] The present invention further provides copolymers formed by ring-opening polymerization of a monomer mixture comprising:

[0026] - Cyclic comonomers selected from the list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and,

[0027] - Based on compounds with structure I:

[0028] (I),

[0029] Among them, R1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms; and,

[0030] Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, ynyl, or cycloalkenyl group having 1 to 8 carbon atoms (preferably 1 to 6 carbon atoms) and optional heteroatoms; or,

[0031] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0032] Preferably, the copolymer is obtained by or through the synthesis methods described herein.

[0033] In some embodiments, the copolymer is a linear, cyclic, or branched copolymer. Preferably, the linear copolymer is selected from alternating copolymers, random copolymers, statistical copolymers, or block or segment copolymers. Or preferably, the cyclic copolymer is selected from alternating cyclic copolymers, random cyclic copolymers, statistical cyclic copolymers, or block or segment cyclic copolymers. Or preferably, the branched copolymer is selected from graft copolymers, star copolymers, or branched copolymers with different structures.

[0034] In some embodiments, the copolymer has a melting peak at 60.0°C or higher, as determined by differential scanning calorimetry (DSC), particularly in the range of 60.0 to 240.0°C, particularly from 100.0 to 200.0°C, and more particularly from 120.0 to 160.0°C.

[0035] In some embodiments, the copolymer has a weight-average molecular weight (Mw) ranging from 1,000 to 500,000 g / mol, as determined by gel permeation chromatography (GPC).

[0036] In some embodiments, the copolymer has a number-average molecular weight (Mn) ranging from 1,000 to 500,000 g / mol, as determined by gel permeation chromatography (GPC).

[0037] In some embodiments, the copolymer has a weight-average molecular weight (Mw) from 1,000 to 500,000 g / mol and a number-average molecular weight (Mn) from 1,000 to 500,000 g / mol, as determined by gel permeation chromatography (GPC).

[0038] In some embodiments, the copolymer has a crystallinity between 5% and 50%.

[0039] The present invention further provides the use of the compound according to structure (I) as a biodegradation accelerator or biodegradable olfactory indicator in condensation polymers, preferably in condensation polymers containing esters or amides, and preferably in polylactic acid, polycaprolactone and polycaprolactam.

[0040] (I),

[0041] Among them, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 An alkyl group having 1 to 6 carbon atoms; and,

[0042] Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0043] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0044] The present invention further provides articles comprising copolymers according to embodiments described herein, or copolymers produced by methods according to embodiments described herein.

[0045] The present invention further provides compounds according to structure (I),

[0046] (I),

[0047] Among them, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 An alkyl group having 1 to 6 carbon atoms; and,

[0048] Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0049] Among them, R 2 and R 3Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0050] Preferred embodiments of the invention are disclosed in the detailed description and the appended claims. In the following paragraphs, different aspects of the invention are defined in more detail. Each aspect thus defined may be combined with any other single or multiple aspects unless expressly indicated to the contrary. In particular, any feature indicated as preferred or advantageous may be combined with any other single or multiple features indicated as preferred or advantageous. An embodiment of one aspect of the invention is also an embodiment of all other aspects of the invention. Detailed Implementation

[0051] In describing this invention, the terminology used will be understood according to the following definitions unless the context otherwise requires.

[0052] Unless otherwise defined, all terms used in this invention, including technical and scientific terms, shall have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains. Further guidance includes definitions of terms to better understand the teachings of this invention.

[0053] In the following paragraphs, different aspects of the invention are defined in more detail. These aspects may be combined with any other one or more other aspects unless explicitly indicated to the contrary. In particular, any feature indicated as preferred or advantageous may be combined with any other one or more features indicated as preferred or advantageous.

[0054] The terms "one embodiment" or "an embodiment" used throughout this specification refer to a particular feature, structure, or characteristic described in relation to that embodiment being included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in different places throughout this specification do not necessarily all refer to the same embodiment, but may refer to the same embodiment. Furthermore, the particular feature, structure, or characteristic may be combined in any suitable manner in one or more embodiments, as will be apparent to those skilled in the art from this disclosure. Moreover, while some embodiments described herein include certain features, they do not include other features included in other embodiments, and combinations of features from different embodiments are considered to be within the scope of the invention and form different embodiments as understood by those skilled in the art. For example, in the following claims and statements, any of the embodiments can be used in any combination.

[0055] The terms “comprising,” “comprises,” and “comprised of” as used herein are synonymous with “including,” “includes,” “containing,” and “contains,” and are inclusive or open-ended, not excluding additional, unlisted elements, components, or method steps. It should be understood that the terms “comprising,” “comprises,” and “comprised of” as used herein include the terms “consisting of,” “consists,” and “consists of.”

[0056] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include their plural references unless the context clearly indicates otherwise. For example, “a step” means one step or more steps.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art.

[0058] A range of values ​​expressed by endpoints includes all integers within that range and, where appropriate, fractions (e.g., 1 to 5 may include 1, 2, 3, 4 when referring to the number of elements, and 1.5, 2, 2.75, and 3.80 when referring to the measurement value). The expression of endpoints also includes the endpoint values ​​themselves (e.g., 1.0 to 5.0 includes both 1.0 and 5.0). Any range of values ​​expressed herein is intended to include all subranges contained therein.

[0059] As used herein, the term "about" when referring to a measurable value such as a parameter, quantity, duration of time, etc., means encompassing the value represented and a variation beginning at + / - 10% or less, preferably + / - 5% or less, more preferably + / - 1% or less, within which such variation is suitable for implementation in this disclosure. It should be understood that the value referred to by the modifier "about" is itself specific, preferably, and disclosed.

[0060] The terms “weight% (wt%)”, “vol% (vol%)”, or “mol% (mol%)” refer to the percentage of a component by mass, volume, or mole, respectively, based on the total mass, total volume of the material, or total molar amount of the component.

[0061] In describing this invention, the terms used will be understood according to the following definitions, unless the context otherwise requires.

[0062] This invention provides a method for synthesizing copolymers, comprising the step of polymerizing a mixture of monomers, preferably via a ring-opening polymerization step, wherein the monomer mixture comprises:

[0063] - Based on compounds with structure I:

[0064] (I),

[0065] Where R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 An alkyl group having 1 to 6 carbon atoms; and,

[0066] Where R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0067] Where R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3They collectively possess 3 to 12 carbon atoms and optional heteroatoms; and,

[0068] - Cyclic comonomers selected from a list including lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof.

[0069] As used herein, the term "thiodioxolanones" refers to compounds according to structure (I), regardless of R. 1 R 2 and R 3 How is it defined? In other words, it can refer to a pentagonal lactone with a sulfur atom at the β position, where the α and / or γ carbon atoms can be substituted independently.

[0070] In some implementation schemes, R 1 It is a hydrogen, methyl, or ethyl group, preferably R. 1 It is a hydrogen or methyl group, preferably R. 1 It is a methyl group.

[0071] In some implementation schemes, R 2 and R 3 Each is independently an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0072] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They together have 3 to 12 carbon atoms and optional heteroatoms. This structure can provide thioketal-like properties.

[0073] In some implementation schemes, R 2 and R 3 Each is independently an alkyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0074] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They collectively possess 3 to 12 carbon atoms and optional heteroatoms. In some embodiments, R 2 and R 3 Each is independently an alkyl group having 1 to 8 (preferably 1 to 6) carbon atoms. In some embodiments, R 2 and R3 They are the same.

[0075] In some implementation schemes, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They collectively possess 3 to 12 carbon atoms and optional heteroatoms. In some embodiments, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated 3-, 4-, 5-, 6-, or 7-membered rings, making R... 2 and R 3 They collectively possess 3 to 12 carbon atoms and optional heteroatoms. In some embodiments, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated 5-, 6-, or 7-membered rings, making R 2 and R 3 They collectively possess 3 to 12 carbon atoms and optional heteroatoms. In some embodiments, R 2 and R 3 The saturated 5-, 6-, or 7-membered rings formed by the atoms they are connected to make R 2 and R 3 They collectively have 4 to 6 carbon atoms. R 1 R 2 and R 3 The selection of [aspect name] can affect the crystallinity of the obtained copolymer, the rate of polymerization, the hydrophobicity of the obtained copolymer, the biodegradation rate of the obtained copolymer, or the structure of the obtained copolymer.

[0076] In some embodiments, the compound according to structure (I) may be a condensation product of a thiol compound according to structure (II) and an aldehyde or ketone according to structure (III), wherein R 1 R 2 and R 3 Defined in this article.

[0077]

[0078] Preferably, the condensation reaction that forms the compound according to structure (I) is acid-catalyzed, preferably by an organic acid, and more preferably by a sulfonic acid, such as p-toluenesulfonic acid.

[0079] Preferably, the condensation reaction that forms the compound according to structure (I) is carried out in a Dean-Stark water separator, preferably in a solvent that is immiscible with water, such as toluene.

[0080] In some embodiments, the compound according to structure (II) is thiolactic acid or 2-mercaptobutyric acid, preferably thiolactic acid. These compounds have the advantage that, in the final copolymer, the side chains do not excessively disrupt the crystallinity in order to achieve specific properties such as glass transition temperature (Tg), transparency, melting temperature, etc.

[0081] In some implementations, the aldehyde according to structure (III) is selected from a list including acetaldehyde, propionaldehyde, butyraldehyde, pentanal, isovaleraldehyde, hexanal, octanal, benzaldehyde and furfural.

[0082] In some embodiments, the ketone according to structure (III) is selected from a list including acetone, methyl ethyl ketone, 3-pentanone, hexanone, cyclopropanone, cyclobutanone, cyclopentanone, cyclohexanone and isophorone.

[0083] In some embodiments, the monomer mixture contains at least 1.0% by weight, preferably at least 2.0% by weight, preferably at least 5.0% by weight, preferably at least 10.0% by weight, preferably at least 15.0% by weight, preferably at least 20.0% by weight, preferably at least 25.0% by weight of the compound according to structure I.

[0084] In some embodiments, the monomer mixture comprises:

[0085] - At least 30.0% by weight to at most 99.5% by weight, or at least 30.0% by weight to at most 99.0% by weight, preferably at least 40.0% by weight to at most 98.0% by weight, preferably at least 45.0% by weight to at most 97.0% by weight, preferably at least 50.0% by weight to at most 95.0% by weight, preferably at least 60.0% by weight to at most 90.0% by weight, preferably at least 70.0% by weight to at most 85.0% by weight of a cyclic comonomer selected from the list comprising lactones, lactams, cyclic amines, cyclic esters or mixtures thereof; and,

[0086] - At least 0.50% to at most 70.0% by weight, or at least 1.0% to at most 70.0% by weight, preferably at least 2.0% to at most 60.0% by weight, preferably at least 3.0% to at most 55.0% by weight, preferably at least 5.0% to at most 50.0% by weight, preferably at least 10.0% to at most 40.0% by weight, preferably at least 15.0% to at most 30.0% by weight of the compound according to structure I.

[0087] In some embodiments, the monomer mixture comprises:

[0088] - At least 30.0% by weight, preferably at least 40.0% by weight, preferably at least 45.0% by weight, preferably at least 50.0% by weight, preferably at least 60.0% by weight, preferably at least 70.0% by weight, preferably at least 75.0% by weight of a cyclic comonomer selected from a list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and,

[0089] - At least 0.50% by weight, or at least 1.0% by weight, preferably at least 2.0% by weight, preferably at least 3.0% by weight, preferably at least 5.0% by weight, preferably at least 10.0% by weight, preferably at least 15.0% by weight, preferably at least 20.0% by weight, preferably at least 25.0% by weight of the compound according to structure I.

[0090] In some embodiments, the monomer mixture comprises:

[0091] - At least 70.0% by weight and up to 99.5% by weight, or at least 70.0% by weight and up to 99.0% by weight, of a cyclic comonomer selected from a list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and,

[0092] - At least 0.50% by weight and up to 30.0% by weight, or at least 1.0% by weight and up to 30.0% by weight of the compound according to structure I.

[0093] In some embodiments, the monomer mixture comprises:

[0094] - At least 0.50% by weight to at most 30.0% by weight, or at least 1.0% by weight to at most 30.0% by weight, preferably at least 1.5% by weight to at most 20.0% by weight, preferably at least 2.0% by weight to at most 10.0% by weight, preferably at least 2.5% by weight to at most 7.5% by weight, preferably at least 3.0% by weight to at most 5.0% by weight of the compound according to structure I; and,

[0095] - Preferably, the remainder of the monomer mixture is a cyclic comonomer selected from a list including lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof.

[0096] In some embodiments, the monomer mixture comprises:

[0097] - At least 0.50% by weight, or at least 1.0% by weight, preferably at least 1.5% by weight, preferably at least 2.0% by weight, preferably at least 2.5% by weight, preferably at least 3.0% by weight of the compound according to structure I; and,

[0098] - Preferably, the remainder of the monomer mixture is a cyclic comonomer selected from a list including lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof.

[0099] In some implementations, the cyclic comonomer contains 5- to 7-membered heterocycles.

[0100] In some embodiments, the cyclic comonomer is a lactone or lactam; preferably lactide, caprolactone, or caprolactam.

[0101] In some embodiments, the polymerization method disclosed herein is a ring-opening polymerization method. As used herein, "ring-opening polymerization" or "ROP" refers to a form of chain-growing polymerization in which the ends of the polymer chains attack cyclic monomers to form longer polymers. ROP is a common method used in the synthesis of biopolymers.

[0102] In some embodiments, the monomer mixture is contacted with an initiator and / or a catalyst.

[0103] In some embodiments, the methods disclosed herein are provided to occur in the presence of a catalyst, preferably selected from:

[0104] - Brønsted acids, such as trifluoromethanesulfonic acid or phosphoric acid derivatives;

[0105] - Organic bases, such as 4-(dimethylamino)pyridine or 1,5,7-triazabicyclo[4.4.0]decyl-5-ene (TBD), triethylamine (TEA);

[0106] - Diphenyl phosphate (DPP).

[0107] -N-heterocyclic carbene; or

[0108] - Tin (II) substances, such as tin octoate.

[0109] In some embodiments, the method disclosed herein provides that it occurs in the presence of an initiator of the formula R-OH or R-SH; wherein R is selected from C 6-30 Aryl C 1-20 Alkyl, C 1-20 Alkyl, C 3-10 cycloalkyl, C 6-30 Aryl, C 5-6 heteroaryl and C 5-6 Heterocyclic group, which is optionally surrounded by one or more elements selected from halogens, hydroxyl groups, and C. 1-6 Alkyl substituents are used for substitution; preferably, the initiator is benzyl alcohol (BnOH) or benzyl thiol (BnSH).

[0110] In some embodiments, the method disclosed herein is provided to be carried out in the absence of a solvent. In some embodiments, the polymerization in this method is melt polymerization.

[0111] In some implementations, the polymerization is carried out under reduced pressure.

[0112] In some embodiments, the method includes a step of subjecting the formed copolymer to reduced pressure. This reduced pressure can remove unreacted monomers and / or ketones (R) released during the polymerization reaction. 2 -CO-R 3 (or aldehyde). Preferably, the pressure reduction is at most 1000 mbar, more preferably at most 750 mbar, more preferably at most 500 mbar, more preferably at most 250 mbar, more preferably at most 100 mbar, more preferably at most 50 mbar, more preferably at most 20 mbar.

[0113] In some embodiments, the methods disclosed herein provide copolymerization at temperatures ranging from at least 100.0°C to at most 220.0°C, preferably from at least 120.0°C to at most 200.0°C, and more preferably from at least 140.0°C to at most 180.0°C.

[0114] In some embodiments, the method disclosed herein is provided to occur in solvents such as dichloromethane (DCM), chloroform, tetrahydrofuran (THF), or toluene. The use of solvents is expected to lower the temperature required for the polymerization reaction to occur, or even push that temperature down to room temperature.

[0115] The present invention further provides copolymers formed by ring-opening polymerization of a monomer mixture comprising:

[0116] - Cyclic comonomers selected from the list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and,

[0117] - Based on compounds with structure I:

[0118] (I),

[0119] Where R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 An alkyl group having 1 to 6 carbon atoms; and,

[0120] Where R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0121] Where R2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0122] In some embodiments, the copolymer is a linear, cyclic, or branched copolymer. Preferably, the linear copolymer is selected from alternating copolymers, random copolymers, statistical copolymers, or block or segment copolymers. Or preferably, the cyclic copolymer is selected from alternating cyclic copolymers, random cyclic copolymers, statistical cyclic copolymers, or block or segment cyclic copolymers. Or preferably, the branched copolymer is selected from graft copolymers, star copolymers, or branched copolymers with different structures.

[0123] In some embodiments, the copolymer has a melting peak at 60.0°C or higher, as determined by differential scanning calorimetry (DSC), particularly in the range of 60.0 to 240.0°C, particularly from 100.0 to 200.0°C, and more particularly from 120.0 to 160.0°C.

[0124] In some embodiments, the copolymer has a weight-average molecular weight (Mw) of 1,000 to 500,000 g / mol, preferably 2,000 to 400,000 g / mol, preferably 5,000 to 300,000 g / mol, preferably 10,000 to 200,000 g / mol, preferably 50,000 to 100,000 g / mol, determined by gel permeation chromatography (GPC). Gel permeation chromatography (GPC) (also referring to size exclusion chromatography (SEC)) is typically calibrated using polystyrene standards. In some embodiments, the copolymer has a weight-average molecular weight (Mw) of at least 1,000 g / mol, preferably at least 5,000 g / mol, preferably at least 10,000 g / mol, preferably at least 50,000 g / mol, preferably at least 100,000 g / mol, preferably at least 200,000 g / mol, determined by gel permeation chromatography (GPC).

[0125] In some embodiments, the copolymer has a number-average molecular weight (Mn) of 1,000 to 500,000 g / mol, preferably 2,000 to 400,000 g / mol, preferably 5,000 to 300,000 g / mol, preferably 10,000 to 200,000 g / mol, preferably 50,000 to 100,000 g / mol, determined by gel permeation chromatography (GPC). Gel permeation chromatography (GPC) (also referring to size exclusion chromatography (SEC)) is typically calibrated using polystyrene standards. In some embodiments, the copolymer has a number-average molecular weight (Mn) of at least 1,000 g / mol, preferably at least 5,000 g / mol, preferably at least 10,000 g / mol, preferably at least 50,000 g / mol, preferably at least 100,000 g / mol, preferably at least 200,000 g / mol, determined by gel permeation chromatography (GPC).

[0126] In some embodiments, the copolymer has a crystallinity of at least 5.0% to at most 50.0%, preferably at least 10.0% to at most 40.0%, and preferably at least 15.0% to at most 30.0%. In alternative embodiments, the copolymer disclosed herein is characterized as amorphous (0% crystallinity).

[0127] In some embodiments, the copolymer has a crystallinity of at least 5.0%, preferably at least 10.0%, preferably at least 15.0%, and most preferably at least 20.0%.

[0128] In some embodiments, the copolymer has a structure according to any one of structures (15), (17) or (19) (see Examples section), preferably wherein n is an integer from 0 to 10000, m is an integer from 0 to 10000, k is an integer from 0 to 10000, p is an integer from 0 to 10000, r is an integer from 0 to 10000, and t is an integer from 0 to 10000.

[0129] In some embodiments, the copolymer is produced by a method according to the embodiments described herein.

[0130] The present invention further provides the use of the compound according to structure (I) as a biodegradation accelerator in a condensation polymer, preferably in a polyester or polyamide, preferably in an ester- or amide-containing condensation polymer, and preferably in polylactic acid, polycaprolactone, or polycaprolactam. The rate of biodegradation can be affected by the amount of the compound according to structure (I) used in the condensation polymer. This allows the biodegradability of the condensation polymer to be coordinated according to specific applications or requirements;

[0131] (I),

[0132] Among them, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 It is an alkyl group having 1 to 6 carbon atoms; and,

[0133] Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0134] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0135] The present invention further provides the use of the compound according to structure (I) as a biodegradable olfactory indicator in a condensation polymer, preferably in a condensation polymer containing an ester or amide, preferably in a polyester or polyamide, and preferably in polylactic acid, polycaprolactone, or polycaprolactam. This use allows for the detection of the biodegradation of the condensation polymer by odor. This allows consumers to determine the state of the condensation polymer or articles prepared from the condensation polymer by its odor;

[0136] (I),

[0137] Among them, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 It is an alkyl group having 1 to 6 carbon atoms; and,

[0138] Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0139] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0140] The present invention further provides articles comprising copolymers according to embodiments described herein, or copolymers produced by methods according to embodiments described herein. In particular, the articles can be manufactured by 3D printing, casting, injection molding, extrusion, and / or machining. Filaments prepared from the copolymers disclosed herein can be used for 3D printing.

[0141] In some embodiments, the copolymers disclosed herein can be used in a wide variety of consumer products such as disposable tableware, knives, kitchen appliance housings, and electronic devices such as laptops and handheld devices, as well as microwave oven trays. They can be used in composting bags, food packaging, and loosely filled packaging materials that are cast, injection molded, or spun. They are used in the form of fibers for monofilament fishing lines and nets. They are used in the form of nonwoven fabrics for furniture upholstery, disposable clothing, awnings, feminine hygiene products, and diapers.

[0142] In some embodiments, the copolymers disclosed herein have applications in the field of engineering plastics that can be blended with other polymers.

[0143] In some embodiments, the copolymers disclosed herein can be used in automotive parts such as floor mats, sheets, and covers.

[0144] The copolymers disclosed herein can be used in the form of fibers for monofilament fishing lines, nets for vegetation and weed control, as well as for sandbags, planting pots, binding straps, and ropes.

[0145] The present invention further provides compounds according to structure (I),

[0146] (I),

[0147] Among them, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms, preferably R. 1 It is an alkyl group having 1 to 6 carbon atoms; and,

[0148] Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, alkynyl, or cycloalkenyl group having 1 to 8 (preferably 1 to 6) carbon atoms and optional heteroatoms; or,

[0149] Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

[0150] The present invention will be more readily understood with reference to the following embodiments. The inclusion of embodiments is merely for the purpose of illustrating specific aspects and embodiments of the invention and is not intended to limit the invention.

[0151] Example

[0152] Methods section

[0153] Gel permeation chromatography (GPC)

[0154] Molecular weight (M) n (Number average molecular weight), M w (weight-average molecular weight) and dispersion (M w / M n The sample was determined by size exclusion chromatography (SEC) and, specifically, gel permeation chromatography (GPC) with infrared detection. In simple terms, a 5 mg / mL polymer sample was dissolved in HFIP. Approximately 1 µL of the sample was injected into a PL HFIP gel column.

[0155] Calibration: Calibration was performed using (commercially available) narrow-band polystyrene (PS) standards. The molecular weight M of each fraction i of the eluted polymer was determined based on the Mark-Houwink relationship. i Perform the calculation.

[0156] The average molecular weight used to establish the molecular weight / performance relationship is the number-average molecular weight (M). n ), weight average (M) w ) and z (M) z Molecular weight. These average values ​​are defined by the following expression and are derived from the calculated M. i Sure:

[0157]

[0158] N here i and W i They are respectively those with molecular weight M i The number and weight of molecules. The third (rightmost) representation for each case defines how these averages are obtained from the SEC chromatogram. i The height of the SEC curve at the i-th elution fraction (starting from the baseline) and M i This represents the molecular weight of the substance eluted at this increment.

[0159] In some cases, the elution curve may show two or more peaks, from which different number means (M) can be determined. n ), weight average (M) w ) and z (M) z Molecular weight. For example, the first peak can be labeled as M. n1And the second peak can be labeled M n2 .

[0160] Differential scanning calorimetry (DSC)

[0161] Glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) were determined by differential scanning calorimetry (DSC) on a Netzsch DSC 214 polyma, calibrated using indium and T-zero mode. To erase any previous thermal and crystallization history, the sample was first heated to 240°C at a heating rate of 10°C / min and held at 240°C for 10 minutes. The polymer was then cooled to at most -40°C at a constant cooling rate of 10°C / min and held at -40°C for 10 minutes. The crystallization temperature was determined during this cooling step. The polymer was then heated to 240°C at a constant heating rate of 10°C / min. The glass transition temperature and melting temperature were determined during this heating step. In some cases, the thermogram may show two or more glass transition temperature, crystallization temperature, and / or melting peaks. For example, the first extreme value may be labeled Tg. m1 And the second extreme value can be labeled T. m2 .

[0162] Example 1

[0163] Preparation of compounds based on structure I:

[0164]

[0165] The mixture of thiolactic acid (11) (106.14 g, 1 mol) and methyl ethyl ketone (12) (72.11 g, 1 mol) and p-toluenesulfonic acid (p-TSA) (1.72 g, 0.01 mol) in toluene (1 L) was vigorously stirred (250 rpm) and refluxed under a nitrogen atmosphere (220 °C).

[0166] Water generated during the reaction was removed by forming an azeotrope using a Dean-Stark water separator with a reflux condenser. After 1 hour, the reaction was terminated by adding NaCO3 and washing with a saturated NaCl solution. Following the washing step, the organic layer was dried with magnesium sulfate, and the dried and filtered solution was then purified by removing the solvent. Compound (13) thiodioxolane was obtained in liquid form and in approximately 90% yield.

[0167] Copolymerization of lactide and compounds according to structure I

[0168]

[0169] 10 g of compound (13) and 10 g of lactide (14) were placed in a 100 ml round-bottom flask and dried in an oil bath at 80 °C for 1 hour. Then, 4 ml of a 0.5% solution of stannous octoate (Sn(Oct)2) in toluene was added, and the mixture in the flask was further dried for 30 minutes to remove the toluene. The reaction mixture was rinsed several times with nitrogen, and the flask was sealed in the presence of nitrogen. The initiator used for polymerization was the remaining water present in the mixture. With magnetic stirring, the temperature of the reaction mixture was then gradually increased to 180 °C, and melt polymerization was allowed to proceed at 180 °C for 6 hours, followed by 200 °C for 2 hours. The reaction was stopped by deactivating the catalyst with tartaric acid. Unreacted monomers were then removed by vacuum distillation to obtain a viscous polymer (15).

[0170] Example 2

[0171]

[0172] 0.3 g of compound (13) and 9.7 g of caprolactone (16) were placed in a 100 mL round-bottom flask and dried in an oil bath at 80 °C for 1 hour. Subsequently, 4 mL of a 0.5% solution of stannous octoate (Sn(Oct)2) in toluene was added, and the mixture in the flask was further dried for 30 minutes to remove the toluene. The reaction mixture was repeatedly purged with nitrogen, and the flask was sealed in the presence of nitrogen. The initiator used for polymerization was the remaining water present in the mixture. With magnetic stirring, the temperature of the reaction mixture was then gradually increased to 180 °C, and melt polymerization was allowed to proceed at 180 °C for 6 hours, followed by 200 °C for 2 hours. The reaction was stopped by deactivating the catalyst with tartaric acid. Unreacted monomers were then removed by vacuum distillation to obtain a viscous polymer (17).

[0173] Example 3

[0174]

[0175] 0.5 g of compound (13) and 9.5 g of caprolactam (18) were placed in a 100 mL round-bottom flask and dried in an oil bath at 80 °C for 1 hour. Subsequently, 4 mL of a 0.5% solution of stannous octoate (Sn(Oct)2) in toluene was added, and the mixture in the flask was further dried for 30 minutes to remove the toluene. The reaction mixture was repeatedly purged with nitrogen, and the flask was sealed in the presence of nitrogen. The initiator used for polymerization was the remaining water present in the mixture. With magnetic stirring, the temperature of the reaction mixture was then gradually increased to 180 °C, and melt polymerization was allowed to proceed at 180 °C for 6 hours, followed by 200 °C for 2 hours. The reaction was stopped by deactivating the catalyst with tartaric acid. Unreacted monomers were then removed by vacuum distillation to obtain a viscous polymer (19).

[0176] Example 4

[0177]

[0178] 0.05 g of compound (13) and 9.95 g of lactide (14) were placed in a 100 mL round-bottom flask and dried in an oil bath at 80 °C for 1 hour. Subsequently, 4 mL of a 0.5% solution of stannous octoate (Sn(Oct)2) in toluene was added, and the mixture in the flask was further dried for 30 minutes to remove the toluene. The reaction mixture was repeatedly purged with nitrogen, and the flask was sealed in the presence of nitrogen. The initiator used for polymerization was the remaining water present in the mixture. With magnetic stirring, the temperature of the reaction mixture was then gradually increased to 180 °C, and melt polymerization was allowed to proceed at 180 °C for 6 hours, followed by 200 °C for 2 hours. The reaction was stopped by deactivating the catalyst with tartaric acid. Unreacted monomers were then removed by vacuum distillation to obtain a viscous polymer (15).

[0179] Example 5

[0180]

[0181] 0.10 g of compound (13) and 9.90 g of lactide (14) were placed in a 100 mL round-bottom flask and dried in an oil bath at 80 °C for 1 hour. Subsequently, 4 mL of a 0.5% solution of stannous octoate (Sn(Oct)2) in toluene was added, and the mixture in the flask was further dried for 30 minutes to remove the toluene. The reaction mixture was repeatedly purged with nitrogen, and the flask was sealed in the presence of nitrogen. The initiator used for polymerization was the remaining water present in the mixture. With magnetic stirring, the temperature of the reaction mixture was then gradually increased to 180 °C, and melt polymerization was allowed to proceed at 180 °C for 6 hours, followed by 200 °C for 2 hours. The reaction was stopped by deactivating the catalyst with tartaric acid. Unreacted monomers were then removed by vacuum distillation to obtain a viscous polymer (15).

[0182] Example 6

[0183]

[0184] 0.20 g of compound (13) and 9.80 g of lactide (14) were placed in a 100 mL round-bottom flask and dried in an oil bath at 80 °C for 1 hour. Subsequently, 4 mL of a 0.5% solution of stannous octoate (Sn(Oct)2) in toluene was added, and the mixture in the flask was further dried for 30 minutes to remove the toluene. The reaction mixture was repeatedly rinsed with nitrogen, and the flask was sealed in the presence of nitrogen. The initiator used for polymerization was the remaining water present in the mixture. With magnetic stirring, the temperature of the reaction mixture was then gradually increased to 180 °C, and melt polymerization was allowed to proceed at 180 °C for 6 hours, followed by 200 °C for 2 hours. The reaction was stopped by deactivating the catalyst with tartaric acid. Unreacted monomers were then removed by vacuum distillation to obtain a viscous polymer (15).

[0185] Example 7

[0186]

[0187] 0.50 g of compound (13) and 9.50 g of lactide (14) were placed in a 100 mL round-bottom flask and dried in an oil bath at 80 °C for 1 hour. Subsequently, 4 mL of a 0.5% solution of stannous octoate (Sn(Oct)2) in toluene was added, and the mixture in the flask was further dried for 30 minutes to remove the toluene. The reaction mixture was repeatedly purged with nitrogen, and the flask was sealed in the presence of nitrogen. The initiator used for polymerization was the remaining water present in the mixture. With magnetic stirring, the temperature of the reaction mixture was then gradually increased to 180 °C, and melt polymerization was allowed to proceed at 180 °C for 6 hours, followed by 200 °C for 2 hours. The reaction was stopped by deactivating the catalyst with tartaric acid. Unreacted monomers were then removed by vacuum distillation to obtain a viscous polymer (15).

[0188] Example 8

[0189] Analysis of copolymers of lactide and compounds according to structure I (Examples 4-7)

[0190] The structure and thermal properties of the copolymers (15) prepared in Examples 4-7 were analyzed using gel permeation chromatography (GPC) and differential scanning calorimetry (DSC), as described in the Methods section. The resulting properties are summarized in Tables 1 and 2 below. Without being bound by theory, it is believed that including thiodioxolane compounds in the polymerization mixture can provide differences in reactivity, which may lead to a difference in number-average molecular weight (M). n Different peaks in the molecular weight distribution and molecular weight distribution. Furthermore, the resulting copolymers may contain heterogeneous domains, leading to different peaks including the glass transition temperature (T0). g ) and melting temperature (T) m Thermal transformation.

[0191] Table 1.

[0192]

[0193] Table 2.

[0194]

[0195] This data shows that copolymers with compatible composition and thermal properties can be advantageously obtained.

[0196] It should be understood that although preferred embodiments and / or materials for providing embodiments according to the invention have been discussed, various modifications or changes may be made without departing from the scope and spirit of the invention.

Claims

1. A method for synthesizing a copolymer, comprising the step of polymerization via a ring-opening monomer mixture, said monomer mixture comprising: - At least 70.0% by weight and up to 99.0% by weight of cyclic comonomers selected from a list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and, - At least 1.0% by weight and up to 30.0% by weight of the compound according to structure 1: （I）， in, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms; and, Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, ynyl, or cycloalkenyl group having 1 to 8 carbon atoms and optional heteroatoms; or, Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

2. The method according to claim 1, wherein R 1 It is a methyl or ethyl group, preferably R. 1 It is a methyl group; and / or, wherein, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

3. The method according to claim 1 or 2, wherein the monomer mixture comprises: - At least 30.0% to at most 99.5% by weight, or at least 30.0% to at most 99.0% by weight, preferably at least 40.0% to at most 98.0% by weight, preferably at least 45.0% to at most 97.0% by weight, preferably at least 50.0% to at most 95.0% by weight, preferably at least 60.0% to at most 90.0% by weight, preferably at least 70.0% to at most 85.0% by weight of a cyclic comonomer selected from the list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and, - At least 0.50% to at most 70.0% by weight, or at least 1.0% to at most 70.0% by weight, preferably at least 2.0% to at most 60.0% by weight, preferably at least 3.0% to at most 55.0% by weight, preferably at least 5.0% to at most 50.0% by weight, preferably at least 10.0% to at most 40.0% by weight, preferably at least 15.0% to at most 30.0% by weight of the compound according to structure I.

4. The method according to any one of the preceding claims, wherein the cyclic comonomer comprises a 5- or 7-membered heterocyclic ring.

5. The method according to any one of the preceding claims, wherein the cyclic comonomer is a lactone or a lactam; preferably lactide, caprolactone, or caprolactam.

6. The method according to any one of the preceding claims, wherein the monomer mixture is contacted with an initiator and / or a catalyst.

7. The method according to any one of the preceding claims, wherein the method comprises the step of subjecting the formed copolymer to reduced pressure treatment.

8. A copolymer formed by ring-opening polymerization of a monomer mixture, preferably produced by the method according to any one of claims 1 to 7, the copolymer comprising: - At least 70.0% by weight and up to 99.5% by weight, or at least 30.0% by weight and up to 99.0% by weight, of a cyclic comonomer selected from a list comprising lactones, lactams, cyclic amines, cyclic esters, or mixtures thereof; and, - At least 0.50% by weight and up to 30.0% by weight, or at least 1.0% by weight and up to 30.0% by weight of the compound according to structure I: （I）， in, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms; and, Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, ynyl, or cycloalkenyl group having 1 to 8 carbon atoms and optional heteroatoms; or, Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

9. The copolymer of claim 8, wherein the copolymer is a linear, cyclic, or branched copolymer, preferably wherein the linear copolymer is selected from alternating copolymers, random copolymers, statistical copolymers, or block or segment copolymers, or preferably wherein the cyclic copolymer is selected from alternating cyclic copolymers, random cyclic copolymers, statistical cyclic copolymers, or block or segment cyclic copolymers, or preferably wherein the branched copolymer is selected from graft copolymers, star copolymers, or branched copolymers with different structures.

10. The copolymer according to any one of claims 8 to 9, wherein the copolymer has a melting peak at 60.0°C or higher, as determined by differential scanning calorimetry (DSC), particularly in the range of 60.0 to 240.0°C, particularly from 100.0 to 200.0°C, and more particularly from 120.0 to 160.0°C.

11. The copolymer according to any one of claims 8 to 10, wherein the copolymer has a weight-average molecular weight (Mg) from 1,000 to 500,000 g / mol. w ) and / or number-average molecular weight (M) from 1000 to 500000 g / mol n The concentration was determined by gel permeation chromatography (GPC).

12. The copolymer according to any one of claims 8 to 11, wherein the copolymer has a crystallinity between 5% and 50%.

13. The use of the compound according to structure (I) as a condensation polymer, preferably in a condensation polymer containing an ester or an amide, preferably in polylactic acid, polycaprolactone or polycaprolactam as a biodegradation accelerator or a biodegradable olfactory indicator. （I）， in, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms; and, Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, ynyl, or cycloalkenyl group having 1 to 8 carbon atoms and optional heteroatoms; or, Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

14. Articles comprising the copolymer according to any one of claims 8 to 12, or the copolymer produced by the method according to any one of claims 1 to 7.

15. Based on the compound with structure (I), （I）， in, R 1 It is hydrogen or an alkyl group having 1 to 6 carbon atoms; and, Among them, R 2 and R 3 Each is independently hydrogen or an alkyl, cycloalkyl, aralkyl, aryl, ynyl, or cycloalkenyl group having 1 to 8 carbon atoms and optional heteroatoms; or, Among them, R 2 and R 3 Together with the atoms they are attached to, they form substituted saturated or unsaturated 3-, 4-, 5-, 6-, or 7-membered rings, making R 2 and R 3 They typically have 3 to 12 carbon atoms and optional heteroatoms.

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