Copolymer and method for producing the copolymer

Abstract

The present invention relates to a copolymer having excellent mechanical properties in combination with environmentally friendly and biodegradable properties, and a method for producing the copolymer.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0168707 dated December 6, 2022 and Korean Patent Application No. 10-2023-0175226 dated December 6, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a copolymer and a method for producing the copolymer. [Background technology]

[0003] Polyglycolic acid (PGA) is a type of aliphatic polyester that has attracted attention as an environmentally friendly material that is biodegradable and has excellent tensile strength and elastic modulus.

[0004] Unlike the currently used petroleum-based resins such as polystyrene resin, polyvinyl chloride resin, and polyethylene, it has the effect of preventing the depletion of petroleum resources and suppressing carbon dioxide emissions, thereby reducing the environmental pollution that is a drawback of petroleum-based plastic products. Therefore, as the issue of environmental pollution caused by waste plastics is emerging as a social problem, efforts are being made to expand the scope of application to product areas where general plastics (petroleum-based resins) have been used, such as food packaging materials and containers and electronic product cases.

[0005] However, compared to existing petroleum-based resins, polyglycolic acid has poor elongation to break and exhibits brittleness, which limits its processability and limits its use as a general-purpose resin.

[0006] Therefore, research into copolymers that maintain the mechanical properties of polyglycolic acid while improving elongation properties and the like is required. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a copolymer having excellent biodegradability and improved elongation while maintaining the excellent mechanical properties inherent to polyglycolic acid, and a method for producing the copolymer. [Means for solving the problem]

[0008] According to one embodiment of the present invention, there is provided a copolymer comprising a repeating unit represented by the following Chemical Formula 1, a repeating unit represented by the following Chemical Formula 2, and a repeating unit represented by the following Chemical Formula 3, wherein the repeating unit represented by the Chemical Formula 2 is contained in an amount of 0.9 moles or less per mole of the repeating unit represented by the Chemical Formula 3: [ka] In the above Chemical Formula 1, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more. [ka] [ka] In the above Chemical Formula 3, L2 is an alkylene group having two or more carbon atoms.

[0009] According to another embodiment of the present invention, there is provided a method for preparing a copolymer, comprising: ring-opening polymerizing a glycolide monomer and a monomer represented by the following Chemical Formula 5 in the presence of a compound represented by the following Chemical Formula 4 to prepare a copolymer, wherein the glycolide monomer is contained in an amount of 0.9 moles or less per mole of the monomer represented by the Chemical Formula 5: [ka] In the above Chemical Formula 4, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more; [ka] In the above Chemical Formula 5, L2 is an alkylene group having two or more carbon atoms.

[0010] Copolymers and methods for producing copolymers according to specific embodiments of the invention are described in more detail below.

[0011] Unless otherwise specified throughout this specification, "comprise" or "contain" refers to the inclusion of a certain component (or components) without specific limitations, and should not be interpreted as excluding the addition of other components (or components).

[0012] In the present invention, terms such as first and second are used to describe various components, and the terms are used only to distinguish one component from another.

[0013] Furthermore, unless expressly stated as sequential or continuous, or unless otherwise specifically stated, the steps constituting the manufacturing method described herein should not be construed as being limited to the order in which one step and another step constituting a manufacturing method are described in the specification. Therefore, the order of the steps constituting the manufacturing method may be changed within a range that can be easily understood by a person skilled in the art, and in this case, any changes that are obvious to a person skilled in the art are included within the scope of the present invention.

[0014] Unless otherwise specified herein, the weight-average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, the prepolymer or copolymer is dissolved in chloroform to a concentration of 2 mg / mL, and 20 μL is injected into the GPC. GPC analysis is performed at 40°C. Chloroform is used as the mobile phase for GPC at a flow rate of 1.0 mL / min. Two Agilent Mixed-B columns are used in series, and an RI detector is used as the detector. The Mw value is derived using a calibration curve generated using polystyrene standard specimens. Nine weight-average molecular weights of polystyrene standard specimens were used: 2,000 g / mol, 10,000 g / mol, 30,000 g / mol, 70,000 g / mol, 200,000 g / mol, 700,000 g / mol, 2,000,000 g / mol, 4,000,000 g / mol, and 10,000,000 g / mol.

[0015] In this specification, the term "copolymer" is used to include all of random copolymers, block copolymers, graft copolymers, and the like.

[0016] As used herein, the term "block" refers to a polymer in which two or more repeating units are linked together, and the term "block copolymer" refers to a copolymer in which two or more types of blocks are linked together, each in one or more units, directly or through a linking group.

[0017] According to one embodiment of the present invention, there is provided a copolymer comprising a repeating unit represented by Chemical Formula 1, a repeating unit represented by Chemical Formula 2, and a repeating unit represented by Chemical Formula 3, wherein the repeating unit represented by Chemical Formula 2 is contained in an amount of 0.9 moles or less per mole of the repeating unit represented by Chemical Formula 3.

[0018] The present inventors have discovered that the copolymer of the above embodiment contains both the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2, thereby achieving excellent mechanical properties and elongation at the same time, and have completed the present invention.

[0019] Specifically, by containing the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2 simultaneously, the copolymer of the embodiment can simultaneously achieve the excellent elongation exhibited by the repeating unit represented by Chemical Formula 1 and the excellent mechanical properties exhibited by the repeating unit represented by Chemical Formula 2.

[0020] Furthermore, the present inventors have found that the copolymer of the above embodiment contains 0.9 moles or less of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 3, thereby maintaining excellent mechanical properties and improving elongation, thereby achieving excellent mechanical properties and elongation at the same time, and have completed the present invention.

[0021] Specifically, the copolymer of the embodiment may include a repeating unit represented by the following Chemical Formula 1, a repeating unit represented by the following Chemical Formula 2, and a repeating unit represented by the following Chemical Formula 3:

[0022] [ka]

[0023] In the above Chemical Formula 1, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more. [ka] In the above Chemical Formula 3, L2 is an alkylene group having two or more carbon atoms.

[0024] Conventional copolymers have problems in that they do not contain the repeating unit represented by Chemical Formula 1, and therefore have high melting points and high crystallinity, making them unable to be processed using conventional polymer processing methods such as thermoforming and film processing, and thus limiting processability. Unlike conventional copolymers, the copolymer of one embodiment contains the repeating unit represented by Chemical Formula 1, and therefore has excellent low-temperature physical properties and stability against hydrolysis, while also achieving excellent elongation due to its low glass transition temperature.

[0025] The copolymer may include any of random copolymers, block copolymers, graft copolymers, etc. For example, the copolymer may be a block copolymer.

[0026] A copolymer according to one embodiment of the present invention comprises a first block including a repeating unit represented by Chemical Formula 1, a second block including a repeating unit represented by Chemical Formula 2, and a third block including a repeating unit represented by Chemical Formula 3, and the first and second blocks are bonded via a direct bond, ester bond, amide bond, urethane bond, or carbonate bond, thereby overcoming the drawback of low elongation properties of biodegradable resins containing only polyglycolic acid. Furthermore, these copolymers have excellent biodegradability while complementing the mechanical properties of the respective homopolymers.

[0027] That is, in the copolymer of the embodiment, the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2 may be linked by a direct bond, an ester bond, an amide bond, a urethane bond, a urea bond, or a carbonate bond.

[0028] In addition, in the copolymer of the embodiment, the repeating unit represented by Chemical Formula 2 and the repeating unit represented by Chemical Formula 3 may be linked by a direct bond, an ester bond, an amide bond, a urethane bond, a urea bond, or a carbonate bond.

[0029] In Formula 1, L1 may be an alkylene group having 4 or more carbon atoms, and the alkylene group may be substituted or unsubstituted.

[0030] In addition, in Formula 1, n may be an integer of 5 or more and 5,000 or less.

[0031] Specifically, in Chemical Formula 1, n may be an integer of 5 or more, 10 or more, 5000 or less, 4000 or less, 3000 or less, 2000 or less, 1500 or less, 1000 or less, 500 or less, 100 or less, 50 or less, or 40 or less, and may be an integer of 5 or more to 5000, 5 or more to 4000, 5 or more to 3000, 5 or more to 2000, 5 or more to 1500, 5 or more to 1000, 5 or more to 500, 5 or more to 100, 5 or more to 50, 5 or more to 40, 10 or more to 5000, 10 or more to 4000, 10 or more to 3000, 10 or more to 2000, 10 or more to 1500, 10 or more to 1000, 10 or more to 500, 10 or more to 100, 10 or more to 50, or 10 or more to 40.

[0032] In Chemical Formula 1, n may refer to the number of repeats in the repeating unit represented by Chemical Formula 1. Since n is an integer of 5 or more in Chemical Formula 1, a sufficient elongation can be ensured compared to when n is less than 5.

[0033] In addition, n being 5 or greater in Formula 1 may mean that the copolymer of the embodiment includes a first block containing a repeating unit represented by Formula 1.

[0034] The repeating unit represented by Chemical Formula 1 may be a repeating unit derived from a compound represented by Chemical Formula 4 below. [ka]

[0035] In the above Chemical Formula 4, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more.

[0036] Specifically, in the above Chemical Formula 4, L1 may be an alkylene group having 4 or more carbon atoms, and the alkylene group may be substituted or unsubstituted.

[0037] In addition, in Formula 4, n may be an integer of 5 or more and 5,000 or less.

[0038] Specifically, in Chemical Formula 4, n may be an integer of 5 or more, 10 or more, 5000 or less, 4000 or less, 3000 or less, 2000 or less, 1500 or less, 1000 or less, 500 or less, 100 or less, 50 or less, or 40 or less, such as an integer of 5 or more to 5000, 5 or more to 4000, 5 or more to 3000, 5 or more to 2000, 5 or more to 1500, 5 or more to 1000, 5 or more to 500, 5 or more to 100, 5 or more to 50, 5 or more to 40, 10 or more to 5000, 10 or more to 4000, 10 or more to 3000, 10 or more to 2000, 10 or more to 1500, 10 or more to 1000, 10 or more to 500, 10 or more to 100, 10 or more to 50, or 10 or more to 40.

[0039] Specifically, the repeating unit represented by Chemical Formula 1 may include a repeating unit represented by the following Chemical Formula 1-1. [ka] In the above formula 1-1, R1 to R8 are each independently hydrogen or an alkyl group, and n is an integer of 5 or more.

[0040] In Formula 1-1, n may be an integer of 5 or more and 5,000 or less.

[0041] Specifically, in Chemical Formula 1-1, n may be an integer of 5 or more, 10 or more, 5000 or less, 4000 or less, 3000 or less, 2000 or less, 1500 or less, 1000 or less, 500 or less, 100 or less, 50 or less, or 40 or less, and may be an integer of 5 or more to 5000, 5 or more to 4000, 5 or more to 3000, 5 or more to 2000, 5 or more to 1500, 5 or more to 1000, 5 or more to 500, 5 or more to 100, 5 or more to 50, 5 or more to 40, 10 or more to 5000, 10 or more to 4000, 10 or more to 3000, 10 or more to 2000, 10 or more to 1500, 10 or more to 1000, 10 or more to 500, 10 or more to 100, 10 or more to 50, or 10 or more to 40.

[0042] The copolymer of one embodiment includes a repeating unit represented by Formula 1-1, which provides excellent low-temperature physical properties and hydrolysis stability, and also allows for high-temperature thermoforming, such as polymer processing thermoforming and film processing, thereby achieving excellent processability. Furthermore, the low glass transition temperature results in low crystallinity, which allows for excellent elongation and excellent processability.

[0043] The copolymer of the embodiment may contain 5% by weight or more and 95% by weight or less of the repeating unit represented by Chemical Formula 1 based on the total weight of the repeating units.

[0044] The copolymer of the embodiment contains 5% by weight or more and 95% by weight or less of the repeating units represented by Chemical Formula 1 based on the total weight of the repeating units, thereby maintaining excellent mechanical properties and improving elongation, thereby achieving excellent mechanical properties and elongation at the same time.

[0045] Specifically, the copolymer of the embodiment may contain 5% by weight or more, 10% by weight or more, 15% by weight or more, or 95% by weight or less, 90% by weight or less, 80% by weight or less, 75% by weight or less, 50% by weight or less, 5% by weight or more and 95% by weight or less, 5% by weight or more and 90% by weight or less, 5% by weight or more and 80% by weight or less, 5% by weight or more and 75% by weight or less, 5% by weight or more and 50% by weight or less, 10% by weight or more and 95% by weight or less, 10% by weight or more and 90% by weight or less, 10% by weight or more and 80% by weight or less, 10% by weight or more and 75% by weight or less, 10% by weight or more and 50% by weight or less, 15% by weight or more and 95% by weight or less, 15% by weight or more and 90% by weight or less, 15% by weight or more and 80% by weight or less, 15% by weight or more and 75% by weight or less, 15% by weight or more and 50% by weight.

[0046] The copolymer of the embodiment contains 5% by weight or more and 95% by weight or less of the repeating units represented by Chemical Formula 1 based on the total weight of the repeating units, thereby achieving excellent mechanical properties and elongation at the same time.

[0047] If the copolymer contains less than 5% by weight of the repeating units represented by Chemical Formula 1 relative to the total repeating units, the elongation may be poor and processability may be limited, and if the copolymer contains more than 95% by weight of the repeating units represented by Chemical Formula 1 relative to the total repeating units, mechanical properties may be reduced.

[0048] Meanwhile, the copolymer of the embodiment contains the repeating unit represented by Chemical Formula 2, thereby achieving excellent mechanical properties.

[0049] The repeating unit represented by Chemical Formula 2 may be a repeating unit derived from a glycolide monomer.

[0050] When the compound represented by Chemical Formula 4 is introduced as a comonomer of a glycolide monomer, various physical properties of the glycolide may be improved. However, the physical properties may differ depending on the linking structure of each repeating unit and the degree of introduction of each repeating unit. Therefore, the copolymer of one embodiment can adjust its mechanical properties while maintaining the inherent physical properties of glycolide by adjusting the linking structure of each repeating unit and the degree of introduction of the repeating unit represented by Chemical Formula 1.

[0051] The copolymer may include a repeating unit represented by the following formula 7. [ka] In the above formula 7, m is an integer of 2 or more.

[0052] The inclusion of a repeating unit represented by Chemical Formula 7, where m is an integer of 2 or greater, may mean that the copolymer of the embodiment includes a second block containing a repeating unit represented by Chemical Formula 2.

[0053] The copolymer may include a repeating unit represented by the following formula 3: [ka] In the above Chemical Formula 3, L2 is an alkylene group having two or more carbon atoms.

[0054] When the copolymer contains the repeating unit represented by Chemical Formula 3, it can improve processability, control the rate of biodegradation, and facilitate analysis of the material.

[0055] The repeating unit represented by Chemical Formula 3 may be a repeating unit derived from a compound represented by Chemical Formula 5 below. [ka] In the above Chemical Formula 5, L2 is an alkylene group having two or more carbon atoms.

[0056] The copolymer containing the repeating unit represented by Chemical Formula 3 can be prepared by ring-opening polymerization of the compound represented by Chemical Formula 4, glycolide, and the compound represented by Chemical Formula 5.

[0057] Specifically, the repeating unit represented by Chemical Formula 3 may include a repeating unit represented by the following Chemical Formula 3-1. [ka] The repeating unit represented by the formula 3-1 may be a repeating unit derived from a lactide monomer.

[0058] The copolymer may include a repeating unit represented by the following formula 8. [ka] In the above formula 8, P is an integer of 2 or more.

[0059] The inclusion of a repeating unit represented by Chemical Formula 8, where p is an integer of 2 or greater, may mean that the copolymer of the embodiment includes a third block including a repeating unit represented by Chemical Formula 3.

[0060] Meanwhile, the copolymer may contain 1.1 moles or more of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 1.

[0061] Specifically, the copolymer may contain 1.1 moles or more of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 1.

[0062] More specifically, the copolymer contains 1.1 moles or more, 1.5 moles or more, 2 moles or more, 3 moles or more, 10 moles or more, 15 moles or more, 17 moles or more, 50 moles or less, 40 moles or less, 35 moles or less, 1.1 moles or more and 50 moles or less, 1.5 moles or more and 50 moles or less, 2 moles or more and 50 moles or less, 3 moles or more and 50 moles or less, 10 moles or more and 50 moles or less, 15 moles or more and 50 moles or less and the like. It may contain, for example, 17 to 50 moles, 1.1 to 40 moles, 1.5 to 40 moles, 2 to 40 moles, 3 to 40 moles, 10 to 40 moles, 15 to 40 moles, 17 to 40 moles, 1.1 to 35 moles, 1.5 to 35 moles, 2 to 35 moles, 3 to 35 moles, 10 to 35 moles, 15 to 35 moles, and 17 to 35 moles.

[0063] When the copolymer contains 1.1 moles or more of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 1, excellent mechanical properties can be achieved.

[0064] If the copolymer contains less than 1.1 moles of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 1, the mechanical properties of the final copolymer may be reduced.

[0065] The copolymer may contain 0.9 moles or less of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 3.

[0066] Specifically, the copolymer contains 0.1 moles or more, 0.15 moles or more, 0.16 moles or more, 0.9 moles or less, 0.8 moles or less, 0.75 moles or less, 0.5 moles or less, 0.4 moles or less, 0.1 moles or more and 0.9 moles or less, 0.1 moles or more and 0.8 moles or less, 0.1 moles or more and 0.75 moles or less, 0.1 moles or more and 0.5 moles or less of the repeating unit represented by Chemical Formula 2 relative to 1 mole of the repeating unit represented by Chemical Formula 3. It may contain from 0.1 mol to 0.4 mol, from 0.15 mol to 0.9 mol, from 0.15 mol to 0.8 mol, from 0.15 mol to 0.75 mol, from 0.15 mol to 0.5 mol, from 0.15 mol to 0.4 mol, from 0.16 mol to 0.9 mol, from 0.16 mol to 0.8 mol, from 0.16 mol to 0.75 mol, from 0.16 mol to 0.5 mol, or from 0.16 mol to 0.4 mol.

[0067] The copolymer contains 0.9 moles or less of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 3, thereby achieving the effects of exhibiting excellent tensile elongation, improving heat resistance and biodegradability, and improving moisture and gas barrier properties.

[0068] In addition, the copolymer may include a structure in which one selected from a repeating unit represented by the following Chemical Formula 7 and a repeating unit represented by the following Chemical Formula 8 is bonded to both ends of a functional group represented by the following Chemical Formula 9: [ka] In the above Chemical Formula 7, m is an integer of 2 or more; [ka] In the above formula 8, p is an integer of 2 or more; [ka] In the above formula 9, n is an integer of 5 or more.

[0069] Specifically, the copolymer may include a structure in which the repeating unit represented by Chemical Formula 7 is bonded to both ends of the functional group of Chemical Formula 9, a structure in which the repeating unit represented by Chemical Formula 8 is bonded to both ends of the functional group of Chemical Formula 9, or a structure in which the repeating unit represented by Chemical Formula 7 and the repeating unit represented by Chemical Formula 8 are bonded to both ends of the functional group of Chemical Formula 9, respectively.

[0070] More specifically, the copolymer may include any one selected from the repeating units represented by the following Formulas 10-1 to 10-3. [ka]

[0071] For example, the copolymer may include copolymers represented by the following Chemical Formulas 11-1 to 11-3. [ka]

[0072] The copolymer may have a weight average molecular weight (Mw) of 10,000 g / mol to 500,000 g / mol as measured by gel permeation chromatography (GPC).

[0073] Specifically, the copolymer may have a weight average molecular weight (Mw) measured using gel permeation chromatography (GPC) of 10,000 g / mol or more, 15,000 g / mol or more, 20,000 g / mol or more, 30,000 g / mol or more, 35,000 g / mol or more, 500,000 g / mol or less, 400,000 g / mol or less, 300,000 g / mol or less, 200,000 g / mol or less, or 100,000 g / mol or less, and may have a weight average molecular weight (Mw) of 10,000 g / mol or more, 15,000 g / mol or more, 20,000 g / mol or more, 35,000 g / mol or more, 500,000 g / mol or less, 400,000 g / mol or less, 300,000 g / mol or less, 200,000 g / mol or less, or 100,000 g / mol or less. ol to 500,000g / mol, 20,000g / mol to 500,000g / mol, 30,000g / mol to 500,000g / mol, 35,000g / mol to 500,000g / mol, 10,000g / mol mol to 400,000g / mol, 15,000g / mol to 400,000g / mol, 20,000g / mol to 400,000g / mol, 30,000g / mol to 400,000g / mol, 35,000g / mol mol to 400,000g / mol, 10,000g / mol to 300,000g / mol, 15,000g / mol to 300,000g / mol, 20,000g / mol to 300,000g / mol, 30,000g / mol to 300,000g / mol, 35,000g / mol to 300,000g / mol, 10,000g / mol to 200,000g / mol, 15,000g / mol to 200,000g / mol, 20,000 g / mol to 200,000 g / mol, 30,000 g / mol to 200,000 g / mol, 35,000 g / mol to 200,000 g / mol, 10,000 g / mol to 100,000 g / mol, 15,000 g / mol to 100,000 g / mol, 20,000 g / mol to 100,000 g / mol, 30,000 g / mol to 100,000 g / mol, or 35,000 g / mol to 100,000 g / mol.

[0074] The copolymer of the embodiment may be a biodegradable copolymer that exhibits biodegradability.

[0075] In this specification, a biodegradable resin or biodegradable (co)polymer means a resin or (co)polymer that undergoes natural decomposition when exposed to the outside, specifically, a resin or (co)polymer that undergoes decomposition of 20% by weight or more of the initial weight of the resin or (co)polymer when exposed to the outside environment at room temperature (10°C to 30°C) for 30 days or more.

[0076] That is, the copolymer of one embodiment may undergo spontaneous decomposition when exposed to the outside, specifically, 20% by weight or more of the copolymer may undergo decomposition when exposed to the outside environment at room temperature (10°C to 30°C) for 30 days or more.

[0077] The method for measuring biodegradability is not particularly limited. For example, the moisture content of aerobic compost is set to a level of 40% to 70% at room temperature (10°C to 30°C), and the compost is mixed with resin or (co)polymer in a weight ratio of 10:1. Biodegradability can be measured by calculating the ratio of the mass decomposed into water and CO2 based on the initial mass of the sample over time.

[0078] According to another embodiment of the present invention, there may be provided a method for producing a copolymer, comprising: ring-opening polymerizing a glycolide monomer and a monomer represented by the following Chemical Formula 5 in the presence of a compound represented by the following Chemical Formula 4 to produce a copolymer, wherein the glycolide monomer is contained in an amount of 0.9 moles or less per mole of the monomer represented by the Chemical Formula 5: [ka]

[0079] In the above Chemical Formula 4, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more; [ka] In the above Chemical Formula 5, L2 is an alkylene group having two or more carbon atoms.

[0080] In the method for preparing the copolymer, the compound represented by Formula 4 is used as an initiator and may also be included as a monomer in the final copolymer.

[0081] Specifically, in the above Chemical Formula 4, L1 may be an alkylene group having 4 or more carbon atoms, and the alkylene group may be substituted or unsubstituted.

[0082] In addition, in Chemical Formula 4, n may be an integer of 5 or more and 5,000 or less.

[0083] Specifically, in Chemical Formula 4, n may be an integer of 5 or more, 10 or more, 5000 or less, 4000 or less, 3000 or less, 2000 or less, 1500 or less, 1000 or less, 500 or less, 100 or less, 50 or less, or 40 or less, such as an integer of 5 or more to 5000, 5 or more to 4000, 5 or more to 3000, 5 or more to 2000, 5 or more to 1500, 5 or more to 1000, 5 or more to 500, 5 or more to 100, 5 or more to 50, 5 or more to 40, 10 or more to 5000, 10 or more to 4000, 10 or more to 3000, 10 or more to 2000, 10 or more to 1500, 10 or more to 1000, 10 or more to 500, 10 or more to 100, 10 or more to 50, or 10 or more to 40.

[0084] Specifically, the compound represented by Chemical Formula 4 may include a compound represented by the following Chemical Formula 4-1. [ka] In the above chemical formula 4-1, R1 to R8 are each independently hydrogen or an alkyl group, and n is an integer of 5 or more.

[0085] In the method for producing a copolymer according to the embodiment, the copolymer may contain 5% by weight to 95% by weight of repeating units derived from the compound represented by Chemical Formula 4 based on the total weight of repeating units.

[0086] The repeating unit derived from the compound represented by Chemical Formula 4 may be the repeating unit represented by Chemical Formula 1.

[0087] Specifically, the copolymer of the embodiment may contain repeating units derived from the compound represented by Chemical Formula 4 in an amount of 5% by weight or more, 10% by weight or more, 15% by weight or more, or 95% by weight or less, 90% by weight or less, 80% by weight or less, 75% by weight or less, 50% by weight or less, 5% by weight or more and 95% by weight or less, 5% by weight or more and 90% by weight or less, 5% by weight or more and 80% by weight or less, 5% by weight or more and 75% by weight or less, 5% by weight or more and 50% by weight or less, 10% by weight or more and 95% by weight or less, 10% by weight or more and 90% by weight or less, 10% by weight or more and 80% by weight or less, 10% by weight or more and 75% by weight or less, 10% by weight or more and 50% by weight or less, 15% by weight or more and 95% by weight or less, 15% by weight or more and 90% by weight or less, 15% by weight or more and 80% by weight or less, 15% by weight or more and 75% by weight or less, 15% by weight or more and 50% by weight.

[0088] The final copolymer produced by the copolymer production method of the embodiment contains repeating units derived from the compound represented by Chemical Formula 4 in an amount of 5 wt % to 95 wt % of the total repeating units, thereby achieving excellent mechanical properties and elongation at the same time.

[0089] If the copolymer contains less than 5% by weight of the repeating units represented by Chemical Formula 1 relative to the total repeating units, the elongation may be poor and processability may be limited, and if the copolymer contains more than 95% by weight of the repeating units represented by Chemical Formula 1 relative to the total repeating units, mechanical properties may be reduced.

[0090] The molar content of the repeating unit derived from the compound represented by Formula 4 can be achieved by adjusting the ratio of each monomer used in the copolymer of the embodiment.

[0091] If the weight ratio of the compound represented by Formula 4 to the glycolide monomer is less than 1:99, the elongation may be poor and processability may be limited, and if the weight ratio of the compound represented by Formula 4 to the glycolide monomer is more than 99:1, the mechanical properties of the final copolymer may be reduced.

[0092] The compound represented by Formula 4 may have a weight average molecular weight (Mw) of 500 g / mol to 10,000 g / mol as measured by gel permeation chromatography (GPC).

[0093] Specifically, the compound represented by Formula 4 may have a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of 500 g / mol or more, 700 g / mol or more, 800 g / mol or more, 1000 g / mol or more, 10,000 g / mol or less, 5000 g / mol or less, 2000 g / mol or less, or 1500 g / mol or less, and may have a weight average molecular weight (Mw) of 500 g / mol or more, 700 g / mol or more, 800 g / mol or more, 1000 g / mol or more, 10,000 g / mol or more, 500 g / mol or less, 2000 g / mol or less, or 1500 g / mol or less. The molecular weight may be from 00 to 5,000 g / mol, from 800 to 5,000 g / mol, from 1000 to 5,000 g / mol, from 500 to 2,000 g / mol, from 700 to 2,000 g / mol, from 800 to 2,000 g / mol, from 1000 to 2,000 g / mol, from 500 to 1500 g / mol, from 700 to 1500 g / mol, from 800 to 1500 g / mol, from 1000 to 1500 g / mol.

[0094] The step of ring-opening polymerizing the glycolide monomer and the monomer represented by Formula 5 in the presence of the compound represented by Formula 4 to prepare a copolymer can be carried out as bulk polymerization without using a solvent. Here, "using substantially no solvent" can refer to the use of a small amount of solvent to dissolve the catalyst, for example, up to 1 ml of solvent per 1 kg of monomers used. By carrying out bulk polymerization to prepare a copolymer by ring-opening polymerizing the glycolide monomer and the monomer represented by Formula 5 in the presence of the compound represented by Formula 4 to prepare a copolymer, processes such as solvent removal after polymerization can be omitted, and decomposition or loss of resin during the solvent removal process can be suppressed.

[0095] Preferably, in the step of preparing the copolymer by ring-opening polymerization of the glycolide monomer and the monomer represented by Chemical Formula 5 in the presence of the compound represented by Chemical Formula 4, the glycolide monomer may be contained in an amount of 10 to 150 parts by weight per 100 parts by weight of the compound represented by Chemical Formula 4.

[0096] Specifically, in the step of preparing a copolymer by ring-opening polymerization of a glycolide monomer in the presence of the compound represented by Chemical Formula 4, the glycolide monomer may be included in an amount of 10 parts by weight or more, 20 parts by weight or more, 50 parts by weight or more, 60 parts by weight or more, 150 parts by weight or less, 135 parts by weight or less, 10 parts by weight or more and 150 parts by weight or less, 20 parts by weight or more and 150 parts by weight or less, 50 parts by weight or more and 150 parts by weight or less, 60 parts by weight or more and 150 parts by weight or less, 10 parts by weight or more and 135 parts by weight or less, 20 parts by weight or more and 135 parts by weight or less, 50 parts by weight or more and 135 parts by weight or less, 60 parts by weight or more and 135 parts by weight or less, relative to 100 parts by weight of the compound represented by Chemical Formula 4.

[0097] When the glycolide monomer is contained in an amount of less than 10 parts by weight or more than 150 parts by weight per 100 parts by weight of the compound represented by Formula 4, the elongation of the final copolymer may be poor, limiting processability and reducing mechanical properties.

[0098] Meanwhile, the method for preparing the copolymer involves a glycolide ring-opening polymerization reaction, and is therefore carried out in the presence of a glycolide ring-opening catalyst. Preferably, the step of preparing the copolymer by ring-opening polymerization of a glycolide monomer and a monomer represented by Chemical Formula 5 in the presence of a compound represented by Chemical Formula 4 may be carried out in the presence of a catalyst represented by Chemical Formula 6: [Chemical formula 6] MA 1 p A 2 2-p

[0099] In the formula 6, M is Al, Mg, Zn, Ca, Sn, Fe, Y, Sm, Lu, Ti, or Zr; p is an integer from 0 to 2, and A 1 and A 2 are each independently an alkoxy or carboxyl group. For example, the catalyst represented by Chemical Formula 6 may be tin(II) 2-ethylhexanoate (Sn(Oct)2).

[0100] Preferably, the method for producing the copolymer is carried out at a temperature of 150° C. to 200° C. Preferably, the method for producing the copolymer is carried out for 5 minutes to 10 hours, more preferably 10 minutes to 1 hour.

[0101] According to one embodiment of the present invention, there may be provided a molded article molded from a resin composition containing the copolymer. The resin composition containing the copolymer may further contain, in addition to the copolymer, other additives that improve physical properties.

[0102] The molded article can include one or more molded articles selected from the group consisting of an injection molded article, an extrusion molded article, an inflation molded article, a fiber, a nonwoven fabric, a foam, a film, and a sheet.

[0103] The uses of the molded article are not particularly limited, and the molded article may be, for example, an electronic material, a building material, a food packaging material, a food container (disposable cup, tray, etc.), an industrial article, an agricultural article (e.g., mulching film), etc. [Effects of the Invention]

[0104] According to the present invention, a copolymer having excellent biodegradability and improved elongation while maintaining the excellent mechanical properties inherent to polyglycolic acid, and a method for producing the copolymer can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0105] Hereinafter, the present invention will be described in more detail with reference to the following examples, but the following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention.

[0106] <Examples and Comparative Examples> Example 1 A 500 mL Teflon-coated round-bottom flask was charged with 15 g (0.005 mol) of poly(tetramethylene ether) glycol (n = 33, weight-average molecular weight: 3000 g / mol), 10 g (0.086 mol) of glycolide, and 75 g (0.52 mol) of lactide, and the temperature was adjusted to room temperature.

[0107] After adding 39.3 mg of tin(II) 2-ethylhexanoate to the flask, the flask was placed in an oil bath and heated to 220°C under a nitrogen atmosphere, followed by ring-opening polymerization for 2 hours while stirring at 200 rpm. After the reaction was completed, residual monomers were removed through a devolatilization step to obtain the final copolymer.

[0108] Example 2 A copolymer was produced in the same manner as in Example 1, except that 15 g (0.005 mol) of poly(tetramethylene ether) glycol (n=33, weight average molecular weight: 3000 g / mol), 20 g (0.17 mol) of glycolide, 65 g (0.45 mol) of lactide, and 40.4 mg of tin(II) 2-ethylhexanoate were added.

[0109] Comparative Example 1 A copolymer was produced in the same manner as in Example 1, except that 10 g (0.049 mol) of n-dodecanediol, 10 g (0.086 mol) of glycolide, and 1.09 mg of tin(II) 2-ethylhexanoate were added.

[0110] Comparative Example 2 A copolymer was produced in the same manner as in Example 1, except that 15 g (0.005 mol) of poly(tetramethylene ether) glycol (n=33, weight average molecular weight: 3000 g / mol), 38 g (0.33 mol) of glycolide, 47 g (0.33 mol) of lactide, and 42.3 mg of tin(II) 2-ethylhexanoate were added.

[0111] Reference example 1 A copolymer was produced in the same manner as in Example 1, except that 15 g (0.005 mol) of poly(tetramethylene ether) glycol (n=33, weight average molecular weight: 3000 g / mol), 10 g (0.007 mol) of glycolide, 75 g (0.07 mol) of lactide, and 0.066 mg of tin(II) 2-ethylhexanoate were added.

[0112] evaluation (1) GPC (Gel Permeation Chromatography) analysis The weight average molecular weight (Mw) of the copolymers of the above Examples, Comparative Examples and Reference Examples was measured using gel permeation chromatography (GPC, Waters E2640).

[0113] Specifically, each of the copolymers from the Examples, Comparative Examples, and Reference Examples was dissolved in hexafluoroisopropanol (HFIP) to a concentration of 2 mg / mL, and 20 μL of the solution was injected into the GPC. HFIP was used as the mobile phase for GPC, and the flow rate was 1.0 mL / min. Analysis was performed at 40°C. Two Agilent Mixed-B columns were connected in series. An RI detector was used. Mw values were derived from a calibration curve generated using a polymethyl methacrylate (PMMA) standard specimen. Nine weight-average molecular weights of polystyrene standard specimens were used: 2,000 g / mol, 10,000 g / mol, 30,000 g / mol, 70,000 g / mol, 200,000 g / mol, 700,000 g / mol, 2,000,000 g / mol, 4,000,000 g / mol, and 10,000,000 g / mol.

[0114] (3) Physical property evaluation The tensile strength, Young's modulus, and tensile elongation of the copolymers of the Examples, Comparative Examples, and Reference Examples were measured.

[0115] Specifically, the test was carried out according to ASTM D638. After preparing ASTM D536 V Type specimens at 190-200°C using a hot-press machine (Limotem QM900S), the specimens were measured using a UTM (Universal Testing Machine) at 10mm / s and a load of 60kg / f. [Table 1]

[0116] As shown in Table 1, the copolymers of Examples 1 and 2 exhibited tensile elongation of 106.6% or more, and it was confirmed that the elongation was sufficient and that physical properties could be measured through thermoforming and processing. It was also confirmed that the physical properties and processability were improved compared to existing polyglycolic acid.

[0117] On the other hand, the copolymer of Comparative Example 1 exhibited a tensile elongation of 25%, and the copolymer of Comparative Example 2 exhibited a tensile elongation of 63.4%, which confirmed that the copolymers exhibited poor tensile elongation compared to the Examples.

[0118] In addition, it was confirmed that the copolymer of Reference Example 1 was degraded during specimen preparation and fractured due to its high crystallinity and low elongation, making it impossible to prepare specimens. As a result, it was confirmed that thermoforming and processing were impossible.

[0119] (4) Measurement of biodegradability The biodegradability of the cellulose as a standard material and the copolymers of the examples was measured under home composting conditions of EN17427.

[0120] Specifically, the measurements were performed under home composting conditions (28°C, aerobic composting conditions, compost moisture content was set to 50%, compost was mixed with the polymer to be measured at a weight ratio of 10:1, and the CO2 generated was measured). Degradation (%) refers to the calculated mass of the sample decomposed into water and CO2 based on the initial mass. For comparison, the results were also compared with the biodegradation measurement results of a standard substance, cellulose (Sigma Aldrich, Cellulose, Cat. No. 310697).

[0121] Measurement of the decomposition rates of the copolymers of Examples 1 and 2 showed that the initial mass of the sample was decomposed by more than 40% within 40 days, and that the cellulose was decomposed by approximately 60% over the same period, confirming that the biodegradation rate of Example 1 increased over time relative to the biodegradation rate of cellulose. This confirmed that the block copolymers of Examples 1 and 2 possess biodegradability even under relatively mild home composting conditions.

Claims

1. The repeating unit includes a repeating unit represented by the following chemical formula 1, a repeating unit represented by the following chemical formula 2, and a repeating unit represented by the following chemical formula 3: A copolymer containing 0.9 moles or less of a repeating unit represented by the chemical formula 2 per mole of a repeating unit represented by the chemical formula 3: 【Chemical 1】 In the above Chemical Formula 1, Said L １ is an alkylene group having 4 or more carbon atoms, n is an integer of 5 or more, 【Chemistry 2】 【Chemistry 3】 In the above Chemical Formula 3, Said L ２ is an alkylene group having two or more carbon atoms.

2. The copolymer according to claim 1 , wherein the repeating unit represented by Chemical Formula 1 is contained in an amount of 5% by weight to 95% by weight based on the total amount of repeating units.

3. The copolymer according to claim 1, wherein the repeating unit represented by Chemical Formula 1 includes a repeating unit represented by the following Chemical Formula 1-1: 【Chemistry 4】 In the above Chemical Formula 1-1, R １ ~R ８ are each independently hydrogen or an alkyl group, n is an integer of 5 or more.

4. The copolymer according to claim 1 , wherein n is an integer of 5 to 5,000.

5. The copolymer according to claim 1 , comprising 1.1 moles or more of the repeating unit represented by Chemical Formula 2 per mole of the repeating unit represented by Chemical Formula 1.

6. The copolymer of claim 1 , comprising a repeating unit represented by the following chemical formula 7: 【Chemistry 5】 In the above Chemical Formula 7, m is an integer of 2 or more.

7. The copolymer of claim 1 , comprising a repeating unit represented by the following chemical formula 8: 【Chemistry 6】 In the above Chemical Formula 8, p is an integer of 2 or more.

8. The copolymer according to claim 1, comprising a structure in which one selected from a repeating unit represented by the following Chemical Formula 7 and a repeating unit represented by the following Chemical Formula 8 is bonded to both ends of a functional group represented by the following Chemical Formula 9: 【Chemistry 7】 In the above Chemical Formula 7, m is an integer of 2 or more, 【Chemistry 8】 In the above Chemical Formula 8, p is an integer of 2 or more, 【Chemistry 9】 In Formula 9, n is an integer of 5 or more.

9. The copolymer according to claim 1 , wherein the copolymer has a weight average molecular weight of 10,000 g / mol or more and 500,000 g / mol or less.

10. The method includes ring-opening polymerizing a glycolide monomer and a monomer represented by the following Formula 5 in the presence of a compound represented by the following Formula 4 to prepare a copolymer: A method for producing a copolymer comprising 0.9 moles or less of the glycolide monomer per mole of the monomer represented by Chemical Formula 5: 【Chemistry 10】 In the above Chemical Formula 4, Said L １ is an alkylene group having 4 or more carbon atoms, n is an integer of 5 or more, 【Chemistry 11】 In the above Chemical Formula 5, Said L ２ is an alkylene group having two or more carbon atoms.

11. The method for producing a copolymer according to claim 10, wherein the compound represented by Formula 4 has a weight average molecular weight of 500 g / mol to 10,000 g / mol.

12. The method for producing a copolymer according to claim 10 , wherein the glycolide monomer is contained in an amount of 10 to 150 parts by weight based on 100 parts by weight of the compound represented by Chemical Formula 4.

13. 11. The method for producing a copolymer according to claim 10, wherein the step of ring-opening polymerizing the glycolide monomer and the monomer represented by Formula 5 in the presence of the compound represented by Formula 4 is carried out in the presence of a catalyst represented by Formula 6: MA １ ｐ A ２ ２－ｐ In the above Chemical Formula 6, M is Al, Mg, Zn, Ca, Sn, Fe, Y, Sm, Lu, Ti or Zr; p is an integer from 0 to 2; A １ and A ２ are each independently an alkoxy or carboxyl group.

14. The method for producing a copolymer according to claim 13, wherein the catalyst is tin(II) 2-ethylhexanoate.

15. A molded article molded from a resin composition containing the copolymer according to claim 1.

16. The molded article according to claim 15, wherein the molded article comprises one or more molded articles selected from the group consisting of an injection molded article, an extrusion molded article, an inflation molded article, a fiber, a nonwoven fabric, a foam, a film, and a sheet.

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