Copolymer and method for producing copolymer

Abstract

The present invention relates to a copolymer having excellent mechanical properties as well as environmental affinity and biodegradability, and a method for preparing the copolymer.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2022-0168707 filed on December 6, 2022, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2023-0175226 filed on December 6, 2023, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety.

[0003] The present invention relates to copolymers and a process for preparing the copolymers. Background Art

[0004] Polyglycolic acid (PGA) is an aliphatic polyester and is attracting attention as an environmentally friendly material having biodegradability and also having excellent tensile strength and elastic modulus.

[0005] Unlike conventionally used petroleum-based resins such as polystyrene resins, polyvinyl chloride resins, and polyethylene, polylactic acid has effects such as preventing the depletion of petroleum resources and inhibiting carbon dioxide emissions, and thus can reduce environmental pollution that is a disadvantage of petroleum-based plastic products. Therefore, since the environmental pollution problem caused by waste plastics has emerged as a social problem, attempts are being made to expand the scope of application to products using general plastics (petroleum-based resins), such as food packaging materials, containers, and electronic product housings.

[0006] However, polyglycolic acid has poor elongation at break properties compared to conventional petroleum-based resins and exhibits brittleness, which limits its processability and restricts its use as a general-purpose resin.

[0007] Therefore, there is a need to study copolymers that maintain the mechanical properties of polyglycolic acid while improving elongation properties and the like. Summary of the invention

[0008] Technical issues

[0009] An object of the present invention is to provide a copolymer having excellent biodegradability and improved elongation while maintaining excellent mechanical properties inherent to polyglycolic acid, and a method for preparing the copolymer.

[0010] Technical Solution

[0011] 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 Chemical Formula 2 is included in an amount of 0.9 moles or less based on 1 mole of the repeating unit represented by Chemical Formula 3:

[0012] [Chemical formula 1]

[0013]

[0014] Wherein, in Chemical Formula 1, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more,

[0015] [Chemical formula 2]

[0016]

[0017] [Chemical formula 3]

[0018]

[0019] Here, in Chemical Formula 3, L2 is an alkylene group having 2 or more carbon atoms.

[0020] According to another embodiment of the present invention, there is provided a method for preparing a copolymer, the method comprising subjecting a glycolide monomer and a monomer represented by the following Chemical Formula 5 to ring-opening polymerization in the presence of a compound represented by the following Chemical Formula 4 to prepare a copolymer, wherein the glycolide monomer is included in an amount of 0.9 moles or less based on 1 mole of the monomer represented by Chemical Formula 5:

[0021] [Chemical formula 4]

[0022]

[0023] Wherein, in Chemical Formula 4, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more,

[0024] [Chemical formula 5]

[0025]

[0026] Here, in Chemical Formula 5, L2 is an alkylene group having 2 or more carbon atoms.

[0027] Now, a copolymer according to a specific embodiment of the present invention and a method for preparing the copolymer will be described in more detail.

[0028] Unless particularly mentioned herein, the term “include” or “comprising” means including / containing some elements (or components) without any limitation, and should not be interpreted as excluding the addition of other elements (or components).

[0029] The terms “first”, “second”, etc. are used herein to describe various elements, and these terms are only used to distinguish one constituent element from other constituent elements.

[0030] In addition, if the steps constituting the manufacturing method described herein are specified as being sequential or continuous, or unless otherwise specified, a step and other steps constituting a manufacturing method should not be interpreted as being limited to the order described herein. Therefore, the order of the steps constituting the manufacturing method can be changed within the range that can be easily understood by those skilled in the art, and in this case, incidental changes that are obvious to those skilled in the art are not included in the scope of the present invention.

[0031] In addition, unless otherwise specified herein, weight average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, polyester is dissolved in chloroform to a concentration of 2 mg / ml, and then 20 μl of the dissolved solution is injected into GPC, and GPC analysis is performed at 40 ° C. At this time, chloroform is used as the mobile phase for GPC, with a flow rate of 1.0 mL / min, and the column used is two Agilent Mixed-B units connected in series. RI detector is used as a detector. The value of Mw is obtained using a calibration curve formed using a polystyrene standard sample. Nine polystyrene standard samples with molecular weights of 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 are used.

[0032] As used herein, copolymer is meant to include random copolymers, block copolymers, graft copolymers, and the like.

[0033] As used herein, the term "block" refers to a polymer comprising at least two repeating units connected to each other, wherein the repeating units are identical. The term "block copolymer" refers to a copolymer comprising at least two types of different blocks connected to each other via a direct bond or via a linking group, wherein there is one or more blocks of each block type.

[0034] According to one embodiment of the present invention, there is provided a copolymer including 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 included in an amount of 0.9 moles or less based on 1 mole of the repeating unit represented by Chemical Formula 3.

[0035] The present inventors have found that when the copolymer of the above embodiment includes both the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2, excellent mechanical properties and elongation can be simultaneously achieved, and have completed the present invention.

[0036] Specifically, when the copolymer of the above embodiment includes both the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2, 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 can be simultaneously achieved.

[0037] The present inventors also found that when the copolymer of the above embodiment contains 0.9 moles or less of the repeating unit represented by Chemical Formula 2 based on 1 mole of the repeating unit represented by Chemical Formula 3, it maintains excellent mechanical properties while improving elongation, and thus can simultaneously achieve excellent mechanical properties and elongation, and complete the present invention.

[0038] Specifically, the copolymer of one 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.

[0039] [Chemical formula 1]

[0040]

[0041] Wherein, in Chemical Formula 1, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more,

[0042] [Chemical formula 2]

[0043]

[0044] [Chemical formula 3]

[0045]

[0046] Here, in Chemical Formula 3, L2 is an alkylene group having 2 or more carbon atoms.

[0047] Since conventional copolymers do not include the repeating unit represented by Chemical Formula 1, conventional common polymer processing methods such as thermoforming and film processing methods are impossible due to the high melting point and high crystallinity of the copolymer, which leads to the problem of limiting processability. Unlike conventional copolymers, the copolymer according to one embodiment of the present invention includes the repeating unit represented by Chemical Formula 1, and thus has excellent low-temperature physical properties and anti-hydrolysis stability, and due to the low glass transition temperature, can also achieve excellent elongation.

[0048] The copolymer may include a random copolymer, a block copolymer, a graft copolymer, etc. For example, the copolymer may be a block copolymer.

[0049] The copolymer according to one embodiment of the present invention comprises a first block containing a repeating unit represented by Chemical Formula 1, a second block containing a repeating unit represented by Chemical Formula 2, and a third block containing a repeating unit represented by Chemical Formula 3, wherein the first block and the second block are directly bonded, ester-bonded, amide-bonded, carbamate-bonded, or carbonate-bonded. Therefore, the disadvantage of low elongation characteristics of biodegradable resins containing only polyglycolic acid can be compensated. In addition, these copolymers have excellent biodegradability while compensating for the mechanical properties of each homopolymer.

[0050] That is, in the copolymer of one embodiment, the repeating unit represented by Chemical Formula 1 and the repeating unit represented by Chemical Formula 2 may be connected by a direct bond, an ester bond, an amide bond, a urethane bond, a urea bond, or a carbonate bond.

[0051] Furthermore, in the copolymer of one embodiment, the repeating unit represented by Chemical Formula 2 and the repeating unit represented by Chemical Formula 3 may be connected through a direct bond, an ester bond, an amide bond, a urethane bond, a urea bond, or a carbonate bond.

[0052] In Chemical Formula 1, L1 may be an alkylene group having 4 or more carbon atoms, and the alkylene group may be substituted or unsubstituted.

[0053] In addition, in Chemical Formula 1, n may be an integer of 5 or more and 5000 or less.

[0054] Specifically, in Chemical Formula 1, n may be an integer of 5 or more, 10 or more, or 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, or may be an integer of 5 or more and 5000 or less, 5 or more and 4000 or less, 5 or more and 3000 or less, 5 or more and 2000 or less, 5 or more and 1500 or less, 5 or more and 1000 or more. or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, 10 or more and 40 or less, 10 or more and 5000 or less, 10 or more and 4000 or less, 10 or more and 3000 or less, 10 or more and 2000 or less, 10 or more and 1500 or less, 10 or more and 1000 or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, or an integer of 10 or more and 40 or less.

[0055] In Chemical Formula 1, n may mean a repetition number of a repeating unit represented by Chemical Formula 1. In Chemical Formula 1, when n is an integer of 5 or more, compared with a case where n is less than 5, sufficient elongation may be ensured.

[0056] In addition, n in Chemical Formula 1 being 5 or more may mean that the copolymer of the above embodiment includes a first block including a repeating unit represented by Chemical Formula 1.

[0057] The repeating unit represented by Chemical Formula 1 may be a repeating unit derived from a compound represented by Chemical Formula 4 below.

[0058] [Chemical formula 4]

[0059]

[0060] Here, in Chemical Formula 4, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more.

[0061] Specifically, in Chemical Formula 4, L1 may be an alkylene group having 4 or more carbon atoms, wherein the alkylene group may be substituted or unsubstituted.

[0062] In addition, in Chemical Formula 4, n may be an integer of 5 or more and 5000 or less.

[0063] Specifically, in Chemical Formula 4, n may be an integer of 5 or more, 10 or more, or 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, or may be an integer of 5 or more and 5000 or less, 5 or more and 4000 or less, 5 or more and 3000 or less, 5 or more and 2000 or less, 5 or more and 1500 or less, 5 or more and 1000 or more. or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, 10 or more and 40 or less, 10 or more and 5000 or less, 10 or more and 4000 or less, 10 or more and 3000 or less, 10 or more and 2000 or less, 10 or more and 1500 or less, 10 or more and 1000 or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, or an integer of 10 or more and 40 or less.

[0064] Specifically, the repeating unit represented by Chemical Formula 1 may include a repeating unit represented by the following Chemical Formula 1-1:

[0065] [Chemical formula 1-1]

[0066]

[0067] In Chemical Formula 1-1, R1 to R8 are each independently hydrogen or an alkyl group, and n is an integer of 5 or more.

[0068] In Chemical Formula 1-1, n may be an integer of 5 or more and 5000 or less.

[0069] Specifically, in Chemical Formula 1-1, n may be an integer of 5 or more, 10 or more, or 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, or may be an integer of 5 or more and 5000 or less, 5 or more and 4000 or less, 5 or more and 3000 or less, 5 or more and 2000 or less, 5 or more and 1500 or less, 5 or more and 1000 or less. or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, 10 or more and 40 or less, 10 or more and 5000 or less, 10 or more and 4000 or less, 10 or more and 3000 or less, 10 or more and 2000 or less, 10 or more and 1500 or less, 10 or more and 1000 or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, or 10 or more and 40 or less integer.

[0070] When the copolymer of one embodiment includes the repeating unit represented by Chemical Formula 1-1, it has excellent low temperature physical properties and anti-hydrolysis stability, and at the same time allows high temperature thermoforming, such as polymer processing method thermoforming and film processing method, and thus can achieve excellent processability. In addition, due to the low glass transition temperature, the crystallinity is reduced, so that excellent elongation and excellent processability can be achieved.

[0071] The copolymer of the above embodiment may include the repeating unit represented by Chemical Formula 1 in an amount of 5 wt % or more and 95 wt % or less based on the entire repeating units.

[0072] Since the copolymer of the above embodiment includes the repeating unit represented by Chemical Formula 1 in an amount of 5 wt % or more and 95 wt % or less based on the total repeating units, it can maintain excellent mechanical properties and have improved elongation, which makes it possible to simultaneously achieve excellent mechanical properties and elongation.

[0073] Specifically, the copolymer of the above embodiment may contain the repeating unit represented by Chemical Formula 1 in the following amounts, based on the total repeating units: 5 wt % or more, 10 wt % or more, 15 wt % or more, or 95 wt % or less, 90 wt % or less, 80 wt % or less, 75 wt % or less, 50 wt % or less, 5 wt % or more and 95 wt % or less, 5 wt % or more and 90 wt % or less, 5 wt % or more and 80 wt % or less, 5 wt % or more and 75 wt % or less, 5 wt % or more And 50 weight % or less, 10 weight % or more and 95 weight % or less, 10 weight % or more and 90 weight % or less, 10 weight % or more and 80 weight % or less, 10 weight % or more and 75 weight % or less, 10 weight % or more and 50 weight % or less, 15 weight % or more and 95 weight % or less, 15 weight % or more and 90 weight % or less, 15 weight % or more and 80 weight % or less, 15 weight % or more and 75 weight % or less, or 15 weight % or more and 50 weight % or less.

[0074] Since the copolymer of the above embodiment includes the repeating unit represented by Chemical Formula 1 in an amount of 5 wt % or more and 95 wt % or less based on the entire repeating units, excellent mechanical properties and elongation may be simultaneously achieved.

[0075] If the copolymer includes the repeating unit represented by Chemical Formula 1 in an amount of less than 5 wt % based on the total repeating units, elongation is poor, which may thus limit processability. If the repeating unit represented by Chemical Formula 1 is included in an amount of more than 95 wt % based on the total repeating units, mechanical properties may be deteriorated.

[0076] Meanwhile, since the copolymer of one embodiment includes the repeating unit represented by Chemical Formula 2, excellent mechanical characteristics may be achieved.

[0077] The repeating unit represented by Chemical Formula 2 may be a repeating unit derived from a glycolide monomer.

[0078] When the compound represented by Chemical Formula 4 is introduced into the comonomer of glycolide monomer, various physical properties of glycolide can be improved, but the physical properties may be presented differently depending on the connection structure of each repeating unit and the introduction degree of each repeating unit. Therefore, the copolymer of one embodiment can adjust the mechanical properties while maintaining the physical properties inherent to glycolide by adjusting the connection structure of each repeating unit and the introduction degree of the repeating unit represented by Chemical Formula 1.

[0079] The copolymer may include a repeating unit represented by the following Chemical Formula 7.

[0080] [Chemical formula 7]

[0081]

[0082] In Chemical Formula 7, m is an integer of 2 or more.

[0083] Including the repeating unit represented by Chemical Formula 7 (wherein m is an integer of 2 or more) may mean that the copolymer of the above embodiment includes the second block including the repeating unit represented by Chemical Formula 2.

[0084] The copolymer may include a repeating unit represented by Chemical Formula 3 below.

[0085] [Chemical formula 3]

[0086]

[0087] Here, in Chemical Formula 3, L2 is an alkylene group having 2 or more carbon atoms.

[0088] Since the copolymer includes the repeating unit represented by Chemical Formula 3, processability may be improved, a biodegradable rate may be adjusted, and analysis of materials may be facilitated.

[0089] The repeating unit represented by Chemical Formula 3 may be a repeating unit derived from a compound represented by Chemical Formula 5 below.

[0090] [Chemical formula 5]

[0091]

[0092] Here, in Chemical Formula 5, L2 is an alkylene group having 2 or more carbon atoms.

[0093] The copolymer including the repeating unit represented by Chemical Formula 3 may be prepared by subjecting the compound represented by Chemical Formula 4, glycolide, and the compound represented by Chemical Formula 5 to ring-opening polymerization.

[0094] Specifically, the repeating unit represented by Chemical Formula 3 may include a repeating unit represented by the following Chemical Formula 3-1.

[0095] [Chemical formula 3-1]

[0096]

[0097] The repeating unit represented by Chemical Formula 3-1 may be a repeating unit derived from a lactide monomer.

[0098] The copolymer may include a repeating unit represented by Chemical Formula 8 below.

[0099] [Chemical formula 8]

[0100]

[0101] Here, in Chemical Formula 8, p is an integer of 2 or more.

[0102] Including the repeating unit represented by Chemical Formula 8 (wherein p is an integer of 2 or more) may mean that the copolymer of the above embodiment includes the third block including the repeating unit represented by Chemical Formula 3.

[0103] Meanwhile, the copolymer may include the repeating unit represented by Chemical Formula 2 in an amount of 1.1 moles or more based on 1 mole of the repeating unit represented by Chemical Formula 1.

[0104] Specifically, the copolymer may include the repeating unit represented by Chemical Formula 2 in an amount of 1.1 moles or more based on 1 mole of the repeating unit represented by Chemical Formula 1.

[0105] More specifically, the copolymer may include the repeating unit represented by Chemical Formula 2 in an amount of 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, 17 moles or more and 50 ... The invention relates to an aqueous solution of at least 50 moles or less, 1.1 moles or more and 40 moles or less, 1.5 moles or more and 40 moles or less, 2 moles or more and 40 moles or less, 3 moles or more and 40 moles or less, 10 moles or more and 40 moles or less, 15 moles or more and 40 moles or less, 17 moles or more and 40 moles or less, 1.1 moles or more and 35 moles or less, 1.5 moles or more and 35 moles or less, 2 moles or more and 35 moles or less, 3 moles or more and 35 moles or less, 10 moles or more and 35 moles or less, 15 moles or more and 35 moles or less, or 17 moles or more and 35 moles or less.

[0106] Since the copolymer includes the repeating unit represented by Chemical Formula 2 in an amount of 1.1 moles or more based on 1 mole of the repeating unit represented by Chemical Formula 1, excellent mechanical properties may be achieved.

[0107] If the copolymer includes the repeating unit represented by Chemical Formula 2 in an amount less than 1.1 moles based on 1 mole of the repeating unit represented by Chemical Formula 1, mechanical properties of the finally prepared copolymer may be deteriorated.

[0108] In addition, the copolymer may include the repeating unit represented by Chemical Formula 2 in an amount of 0.9 mol or less based on 1 mol of the repeating unit represented by Chemical Formula 3.

[0109] Specifically, the copolymer may include the repeating unit represented by Chemical Formula 2 in an amount of 0.1 mol or more, 0.15 mol or more, 0.16 mol or more, 0.9 mol or less, 0.8 mol or less, 0.75 mol or less, 0.5 mol or less, 0.4 mol or less, 0.1 mol or more and 0.9 mol or less, 0.1 mol or more and 0.8 mol or less, 0.1 mol or more and 0.75 mol or less, 0.1 mol or more and 0.5 mol or less, 0.1 mol or more and 0.9 mol or less, 0.1 mol or more and 0.8 mol or less, 0.1 mol or more and 0.75 mol or less, 0.1 mol or more and 0.5 mol or less, 0.1 mol or more mol or less, 0.15 mole or more and 0.4 mole or less, 0.15 mole or more and 0.9 mole or less, 0.15 mole or more and 0.8 mole or less, 0.15 mole or more and 0.75 mole or less, 0.15 mole or more and 0.5 mole or less, 0.15 mole or more and 0.4 mole or less, 0.16 mole or more and 0.9 mole or less, 0.16 mole or more and 0.8 mole or less, 0.16 mole or more and 0.75 mole or less, 0.16 mole or more and 0.5 mole or less, or 0.16 mole or more and 0.4 mole or less.

[0110] Since the copolymer includes the repeating unit represented by Chemical Formula 2 in an amount of 0.9 mol or less based on 1 mol of the repeating unit represented by Chemical Formula 3, it can exhibit excellent tensile elongation and achieve the effects of improving heat resistance and biodegradability and improving moisture and gas barrier properties.

[0111] In addition, the copolymer may include a structure in which any one selected from the repeating unit represented by Chemical Formula 7 and the repeating unit represented by Chemical Formula 8 is bonded to both ends of a functional group represented by the following Chemical Formula 9.

[0112] [Chemical formula 7]

[0113]

[0114] Wherein, in Chemical Formula 7, m is an integer of 2 or more,

[0115] [Chemical formula 8]

[0116]

[0117] Wherein, in Chemical Formula 8, p is an integer of 2 or more, and

[0118] [Chemical formula 9]

[0119]

[0120] In Chemical Formula 9, n is an integer of 5 or more.

[0121] Specifically, the copolymer may include a structure in which a repeating unit represented by Chemical Formula 7 is bonded to both ends of a functional group of Chemical Formula 9, or a structure in which a repeating unit represented by Chemical Formula 8 is bonded to both ends of a functional group of Chemical Formula 9, or a structure in which a repeating unit represented by Chemical Formula 7 and a repeating unit represented by Chemical Formula 8 are respectively bonded to both ends of a functional group of Chemical Formula 9.

[0122] More specifically, the copolymer may include any one selected from repeating units represented by the following Chemical Formulae 10-1 to 10-3.

[0123] [Chemical formula 10-1]

[0124]

[0125] [Chemical formula 10-2]

[0126]

[0127] [Chemical formula 10-3]

[0128]

[0129] For example, the copolymer may include copolymers represented by the following Chemical Formulas 11-1 to 11-3.

[0130] [Chemical formula 11-1]

[0131]

[0132] [Chemical formula 11-2]

[0133]

[0134] [Chemical formula 11-3]

[0135]

[0136] The copolymer may have a weight average molecular weight (Mw) measured using gel permeation chromatography (GPC) of 10,000 g / mol or more and 500,000 g / mol or less.

[0137] Specifically, the weight average molecular weight (Mw) of the copolymer measured using gel permeation chromatography (GPC) may be 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, 100,000 g / mol or less, and 10,000 g / mol or more and 500,000 g / mol or less, 15,000 g / mol or more and 150,000 g / mol or more and 200,000 g / mol or less. 500,000 g / mol or less, 20,000 g / mol or more and 500,000 g / mol or less, 30,000 g / mol or more and 500,000 g / mol or less, 35,000 g / mol or more and 500,000 g / mol or less, 10,000 g / mol or more and 400,000 g / mol or less, 15,000 g / mol or more and 400,000 g / mol or less, 20,000 g / mol or more and 400,000 g / mol or less, 30,000 g / mol or more and 400,000 g / mol or less, 35,000 g / mol or more and 500,000 g / mol or less, 10,000 g / mol or more and 400,000 g / mol or less, 15,000 g / mol or more and 400,000 g / mol or less, 20,000 g / mol or more and 400,000 g / mol or less, 30,000 g / mol or more and 400,000 g / mol or less, 35,000 g / mol or more and 500,000 g / mol or less g / mol or more and 400,000 g / mol or less, 10,000 g / mol or more and 300,000 g / mol or less, 15,000 g / mol or more and 300,000 g / mol or less, 20,000 g / mol or more and 300,000 g / mol or less, 30,000 g / mol or more and 300,000 g / mol or less, 35,000 g / mol or more and 300,000 g / mol or less, 10,000 g / mol or more and 200,000 g / mol or less, 15,000 g / mol or more and 200,000 g / mol or less, 20,000 g / mol or more and 300,000 g / mol or less, g / mol or more and 200,000 g / mol or less, 30,000 g / mol or more and 200,000 g / mol or less, 35,000 g / mol or more and 200,000 g / mol or less, 10,000 g / mol or more and 100,000 g / mol or less, 15,000 g / mol or more and 100,000 g / mol or less, 20,000 g / mol or more and 100,000 g / mol or less, 30,000 g / mol or more and 100,000 g / mol or less, or 35,000 g / mol or more and 100,000 g / mol or less.

[0138] The copolymer of one embodiment may be a biodegradable copolymer exhibiting biodegradability.

[0139] As used herein, a biodegradable resin or a biodegradable (co)polymer means a resin or (co)polymer that causes natural degradation when exposed to the outside. Specifically, it may refer to a resin or (co)polymer that degrades by 20% by weight or more based on the weight of the initial resin or (co)polymer when exposed to an external environment at room temperature (10° C. to 30° C.) for 30 days or longer.

[0140] That is, the copolymer of the above embodiment may cause natural degradation when exposed to the outside, and specifically, may be degraded by more than 20 wt % when exposed to the external environment at room temperature (10° C. to 30° C.) for more than 30 days.

[0141] The method of measuring biodegradability is not particularly limited, but for example, at room temperature (10° C. to 30° C.), the moisture content in aerobic compost is set to a level of 40% to 70%, and then the compost is mixed with a resin or a (co)polymer at a weight ratio of 10:1, and measurement can be performed by calculating the ratio of the mass degraded into water and CO2 with the lapse of time based on the initial mass of the sample.

[0142] According to another embodiment of the present invention, a method for preparing a copolymer may be provided, the method comprising subjecting a glycolide monomer and a monomer represented by the following Chemical Formula 5 to ring-opening polymerization in the presence of a compound represented by the following Chemical Formula 4 to prepare the copolymer, wherein the glycolide monomer is included in an amount of 0.9 moles or less based on 1 mole of the monomer represented by Chemical Formula 5:

[0143] [Chemical formula 4]

[0144]

[0145] Wherein, in Chemical Formula 4, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or more,

[0146] [Chemical formula 5]

[0147]

[0148] Here, in Chemical Formula 5, L2 is an alkylene group having 2 or more carbon atoms.

[0149] In the method for preparing the copolymer, the compound represented by Chemical Formula 4 may be used as an initiator, and may also be included in the final copolymer as a monomer.

[0150] Specifically, in Chemical Formula 4, L1 is an alkylene group having 4 or more carbon atoms, wherein the alkylene group may be substituted or unsubstituted.

[0151] In addition, in Chemical Formula 4, n may be an integer of 5 or more and 5000 or less.

[0152] Specifically, in Chemical Formula 4, n may be an integer of 5 or more, 10 or more, or 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, or may be an integer of 5 or more and 5000 or less, 5 or more and 4000 or less, 5 or more and 3000 or less, 5 or more and 2000 or less, 5 or more and 1500 or less, 5 or more and 1000 or more. or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, 10 or more and 40 or less, 10 or more and 5000 or less, 10 or more and 4000 or less, 10 or more and 3000 or less, 10 or more and 2000 or less, 10 or more and 1500 or less, 10 or more and 1000 or less, 10 or more and 500 or less, 10 or more and 100 or less, 10 or more and 50 or less, or an integer of 10 or more and 40 or less.

[0153] Specifically, the compound represented by Chemical Formula 4 may include a compound represented by the following Chemical Formula 4-1.

[0154] [Chemical formula 4-1]

[0155]

[0156] In Chemical Formula 4-1, R1 to R8 are each independently hydrogen or an alkyl group, and n is an integer of 5 or more.

[0157] In the method for preparing a copolymer according to the above embodiment, the copolymer may include the repeating unit derived from the compound represented by Chemical Formula 4 in an amount of 5 wt % or more and 95 wt % or less based on the entire repeating units.

[0158] The repeating unit derived from the compound represented by Chemical Formula 4 may be the repeating unit represented by Chemical Formula 1.

[0159] Specifically, the copolymer according to the above embodiment may include the repeating unit derived from the compound represented by Chemical Formula 4 in the following amounts, based on the total repeating units: 5 wt % or more, 10 wt % or more, 15 wt % or more, or 95 wt % or less, 90 wt % or less, 80 wt % or less, 75 wt % or less, 50 wt % or less, 5 wt % or more and 95 wt % or less, 5 wt % or more and 90 wt % or less, 5 wt % or more and 80 wt % or less, 5 wt % or more and 75 wt % or less, 5 wt % or more and 50 wt % or less. % or more and 50 wt % or less, 10 wt % or more and 95 wt % or less, 10 wt % or more and 90 wt % or less, 10 wt % or more and 80 wt % or less, 10 wt % or more and 75 wt % or less, 10 wt % or more and 50 wt % or less, 15 wt % or more and 95 wt % or less, 15 wt % or more and 90 wt % or less, 15 wt % or more and 80 wt % or less, 15 wt % or more and 75 wt % or less, or 15 wt % or more and 50 wt % or less.

[0160] Since the final copolymer prepared according to the method for preparing a copolymer according to the above embodiment includes the repeating unit derived from the compound represented by Chemical Formula 4 in an amount of 5 wt % or more and 95 wt % or less based on the entire repeating units, excellent mechanical properties and elongation can be simultaneously achieved.

[0161] If the copolymer includes less than 5 wt % of the repeating unit represented by Chemical Formula 1 based on the total repeating units, elongation is poor, which may limit processability. If the repeating unit represented by Chemical Formula 1 is included in an amount of more than 95 wt % based on the total repeating units, mechanical properties may be deteriorated.

[0162] The molar content of the repeating unit derived from the compound represented by Chemical Formula 4 may be achieved by adjusting the ratio of each monomer used in the copolymer of the above embodiment.

[0163] If the weight ratio of the compound represented by Chemical Formula 4 to the glycolide monomer is less than 1:99, elongation is poor, which may limit processability. If the weight ratio of the compound represented by Chemical Formula 4 to the glycolide monomer is greater than 99:1, mechanical properties may deteriorate.

[0164] The compound represented by Chemical Formula 4 may have a weight average molecular weight (Mw) measured using gel permeation chromatography (GPC) of 500 g / mol to 10,000 g / mol.

[0165] Specifically, the weight average molecular weight (Mw) of the compound represented by Chemical Formula 4 measured using gel permeation chromatography (GPC) may be 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, 1500 g / mol or less, and 500 g / mol or more and 10,000 g / mol or less, 700 g / mol or more and 10,000 g / mol or less, 800 g / mol or more and 10,000 g / mol or less, 1000 g / mol or more and 10,000 g / mol or less, 500 g / mol or more and 5,000 g / mol or less, g / mol or more and 1500 g / mol or less, 700 g / mol or more and 1500 g / mol or less, 800 g / mol or more and 1500 g / mol or less, or 1000 g / mol or more and 1500 g / mol or less.

[0166] The step of 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 to prepare the copolymer can be performed by bulk polymerization as substantially free of solvent. At this time, substantially free of solvent may include using a small amount of solvent to dissolve the catalyst, for example, using less than 1 ml of solvent per kg of the monomer used. Since the step of 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 to prepare the copolymer is performed as bulk polymerization, the step of removing the solvent after the polymerization can be omitted, and degradation or loss of the resin during such a solvent removal process can also be suppressed.

[0167] Preferably, in the step of ring-opening polymerizing the glycolide monomer and the monomer represented by Chemical Formula 5 in the presence of the compound represented by Chemical Formula 4 to prepare the copolymer, the glycolide monomer may be included in an amount of 10 to 150 parts by weight based on 100 parts by weight of the compound represented by Chemical Formula 4.

[0168] Specifically, in the step of subjecting a glycolide monomer and a monomer represented by Chemical Formula 5 to ring-opening polymerization in the presence of a compound represented by Chemical Formula 4 to prepare a copolymer, 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, based on 100 parts by weight of the compound represented by Chemical Formula 4.

[0169] When the glycolide monomer is included in an amount of less than 10 parts by weight or more than 150 parts by weight based on 100 parts by weight of the compound represented by Chemical Formula 4, the elongation of the finally prepared copolymer may be poor, which may limit processability or deteriorate mechanical properties.

[0170] Meanwhile, the method for preparing the copolymer involves a ring-opening polymerization reaction of glycolide, and is therefore carried out in the presence of a glycolide ring-opening catalyst. Preferably, the step of ring-opening polymerization of glycolide monomer and monomer represented by Chemical Formula 5 in the presence of a compound represented by Chemical Formula 4 to prepare the copolymer may be carried out in the presence of a catalyst represented by the following Chemical Formula 6.

[0171] [Chemical formula 6]

[0172] MA 1 p A 2 2-p

[0173] Wherein, in Chemical Formula 6, M is Al, Mg, Zn, Ca, Sn, Fe, Y, Sm, Lu, Ti or Zr,

[0174] p is an integer from 0 to 2, and A 1 and A 2 Each is independently an alkoxy group or a carboxyl group. For example, the catalyst represented by Chemical Formula 4 may be tin(II)-2-ethylhexanoate (Sn(Oct)2).

[0175] Preferably, the process for preparing the copolymer is carried out at a temperature of 150° C. to 200° C. Preferably, the preparation process is carried out for 5 minutes to 10 hours, more preferably for 10 minutes to 1 hour.

[0176] According to one embodiment of the present invention, a molded article molded from a resin composition including the above copolymer may be provided. In addition to the copolymer, the resin composition including the copolymer may further include other additives for improving physical properties.

[0177] The molded article may include one or more molded articles selected from the group consisting of an injection molded article, an extrusion molded article, a blow molded article, a fiber, a nonwoven fabric, a foam, a film, and a sheet.

[0178] The use of the molded product is not particularly limited, but for example, the molded product may be electronic materials, building materials, food packaging, food containers (disposable cups, trays, etc.), industrial products, agricultural products (eg, covering films), etc.

[0179] Beneficial Effects

[0180] According to the present invention, a copolymer having excellent biodegradability and improved elongation while maintaining excellent mechanical properties inherent to polyglycolic acid and a method for preparing the copolymer can be provided. DETAILED DESCRIPTION

[0181] Hereinafter, the present invention will be described in detail with reference to the following examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited thereto.

[0182] <Examples and Comparative Examples>

[0183] Example 1

[0184] 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 were added to a 500 mL Teflon-coated round flask, and the temperature was adjusted to room temperature.

[0185] After adding 39.3 mg of tin (II) 2-ethylhexanoate to the flask, the flask was placed in an oil bath, the temperature was raised to 220° C. under a nitrogen atmosphere, and the mixture was subjected to a ring-opening polymerization reaction for 2 hours while stirring at 200 rpm. After the reaction was completed, the residual monomers were removed by a devolatilization step of the product to obtain the final copolymer.

[0186] Example 2

[0187] A copolymer was prepared in the same manner as in Example 1, except that in Example 1, 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.

[0188] Comparative Example 1

[0189] A copolymer was prepared in the same manner as in Example 1, except that in Example 1, 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.

[0190] Comparative Example 2

[0191] A copolymer was prepared in the same manner as in Example 1, except that in Example 1, 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.

[0192] Reference example 1

[0193] A copolymer was prepared in the same manner as in Example 1, except that in Example 1, 15 g (0.005 mol) of poly(tetramethylene ether) glycol (n=33, number 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.

[0194] Evaluate

[0195] (1) GPC (gel permeation chromatography) analysis

[0196] The weight average molecular weight (Mw) of the copolymers of Examples, Comparative Examples and Reference Examples was measured using gel permeation chromatography (GPC, Waters E2640).

[0197] Specifically, the copolymers of the embodiments, comparative examples and reference examples were dissolved in HFIP (hexafluoroisopropanol) to a concentration of 2 mg / ml, and 20 μl of the dissolved solution was then injected into the GPC. HFIP was used as the mobile phase for GPC with a flow rate of 1.0 mL / min, and the GPC analysis was performed at 40°C. The columns were two Agilent Mixed-B units connected in series. An RI detector was used as a detector. The value of Mw was obtained using a calibration curve formed using polymethyl methacrylate (PMMA). Nine polystyrene standard samples having weight average molecular weights of 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 were used.

[0198] (3) Evaluation of physical properties

[0199] The tensile strength, Young's modulus and tensile elongation of the copolymers of Examples, Comparative Examples and Reference Examples were measured.

[0200] Specifically, the evaluation was performed according to ASTM D638. ASTM D536 V-type test specimens were produced at 190 to 200° C. using a hot press apparatus (Limotem QM900S) and then measured using a UTM apparatus (universal testing machine) at a load of 10 mm / sec and 60 kg / f.

[0201] [Table 1]

[0202] Number average molecular weight (g / mol) Tensile strength(MPa) Young's modulus (MPa) Tensile elongation (%) Example 1 45000 30.4 586 131.7 Example 2 45000 28.9 612 106.6 Comparative Example 1 40000 110 3.2 25 Comparative Example 2 43000 24.8 694 63.4 Reference example 1 3000 Unable to produce samples Unable to produce samples Unable to produce samples

[0203] According to Table 1, it was determined that the copolymers of Examples 1 and 2 exhibited a tensile elongation of 106.6% or more, so that the elongation was ensured, which made it possible to measure physical properties by thermoforming and processing. It was also determined that the physical properties and processability were improved compared to the existing polyglycolic acid. On the other hand, it was determined that 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%, indicating that the tensile elongation was poor compared to the examples.

[0204] In addition, it was determined that the copolymer of Reference Example 1 caused degradation during specimen preparation and broke due to high crystallinity and low elongation, thus making it impossible to prepare the specimen. Therefore, it was determined that thermoforming and processing were impossible.

[0205] (4) Measurement of biodegradation degree

[0206] The biodegradation of cellulose as standard material and the copolymers of the examples was measured under the home composting conditions of EN17427.

[0207] Specifically, under home composting conditions (28°C, aerobic composting conditions), the moisture content in the compost was set to 50%, and then the compost and the polymer were mixed at a weight ratio of 10:1 to measure the generated CO2. Degradation (%) refers to the value obtained by calculating the mass of water and CO2 degraded based on the initial mass of the sample. In addition, for comparison, the results were compared with the biodegradation measurement results of cellulose (Sigma Aldrich, cellulose, catalog number 310697) as a standard substance.

[0208] As a result of the degradation measurement of the copolymers of Examples 1 and 2, it was determined that the copolymers degraded by about 40% or more and the cellulose degraded by about 60% in the same period of time. It was determined that the biodegradation degree of Example 1 increased with the lapse of time compared to the biodegradation degree of cellulose. It was thus determined that the block copolymers of Examples 1 and 2 had biodegradable characteristics even under relatively mild home composting conditions.

Claims

1. 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 Chemical Formula 2 is included in an amount of 0.9 moles or less based on 1 mole of the repeating unit represented by Chemical Formula 3: [Chemical formula 1] in, In Chemical Formula 1, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or greater, [Chemical formula 2] [Chemical formula 3] Wherein, in Chemical Formula 3, L2 is an alkylene group having 2 or more carbon atoms.

2. The copolymer according to claim 1, wherein: The copolymer includes 5 wt % or more and 95 wt % or less of the repeating unit represented by Chemical Formula 1 based on the entire 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: [Chemical formula 1-1] Among them, in chemical formula 1-1, R1 to R8 are each independently hydrogen or alkyl, and n is an integer of 5 or more.

4. The copolymer according to claim 1, wherein: In Chemical Formula 1, n is an integer of 5 or more and 5000 or less.

5. The copolymer according to claim 1, wherein: The repeating unit represented by Chemical Formula 2 is included in an amount of 1.1 moles or more based on 1 mole of the repeating unit represented by Chemical Formula 1.

6. The copolymer according to claim 1, wherein: The copolymer comprises a repeating unit represented by the following Chemical Formula 7: [Chemical formula 7] Among them, in chemical formula 7, m is an integer of 2 or more.

7. The copolymer according to claim 1, wherein: The copolymer comprises a repeating unit represented by the following Chemical Formula 8: [Chemical formula 8] Among them, in chemical formula 8, p is an integer of 2 or more.

8. The copolymer according to claim 1, wherein: The copolymer includes a structure in which any 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: [Chemical formula 7] Among them, in chemical formula 7, m is an integer of 2 or greater, [Chemical formula 8] Among them, in chemical formula 8, p is an integer of 2 or greater, [Chemical formula 9] Among them, in chemical 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. A method for preparing a copolymer, the method comprising subjecting a glycolide monomer and a monomer represented by the following Chemical Formula 5 to ring-opening polymerization in the presence of a compound represented by the following Chemical Formula 4 to prepare a copolymer, wherein the glycolide monomer is included in an amount of 0.9 moles or less based on 1 mole of the monomer represented by Chemical Formula 5: [Chemical formula 4] in, In chemical formula 4, L1 is an alkylene group having 4 or more carbon atoms, and n is an integer of 5 or greater, [Chemical formula 5] Among them, in chemical formula 5, L2 is an alkylene group having 2 or more carbon atoms.

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

12. The method for preparing a copolymer according to claim 10, wherein: The glycolide monomer may be included in an amount of 10 parts by weight or more and 150 parts by weight or less, based on 100 parts by weight of the compound represented by Chemical Formula 4.

13. The method for preparing a copolymer according to claim 10, wherein: The 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 to prepare a copolymer is carried out in the presence of a catalyst represented by the following Chemical Formula 6: [Chemical formula 6] MA 1 p A 2 2-p Among them, in 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, and A 1 and A 2 Each is independently an alkoxy group or a carboxyl group.

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

15. A molded article molded from a resin composition comprising the copolymer according to claim 1. 16 . The molded article according to claim 15 , comprising one or more molded articles selected from the group consisting of injection molded articles, extrusion molded articles, blow molded articles, fibers, nonwoven fabrics, foams, films, and sheets.

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