3-hydroxypropionate (co) polymer composition, poly (lactic acid-b-3-hydroxypropionic acid) block copolymer composition and preparation method thereof

Abstract

The present invention provides a 3-hydracrylate (co) polymer composition comprising a 3-hydracrylate (co) polymer and an isocyanate compound, a poly (lactone-b-3-hydracrylic acid) block copolymer composition comprising a poly (lactone-b-3-hydracrylic acid) block copolymer and an isocyanate compound, and a method for preparing the 3-hydroxypropionate (co) polymer and the poly (lactide-b-3-hydroxypropionic acid) block copolymer.

Description

Technical Field

[0001] The present invention provides a 3-hydroxypropionate (co)polymer composition, a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition, a method for preparing a 3-hydroxypropionate (co)polymer, and a method for preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer. Background Art

[0002] Poly(3-hydroxypropionic acid) has biodegradable properties, and due to these environmentally friendly characteristics, research on its utilization has been actively conducted recently. There are mainly two methods for preparing poly(3-hydroxypropionic acid): one involves using petrochemical-based β-propiolactone (PL), and the other uses bio-based 3-hydroxypropionic acid (3HP).

[0003] When using β-propiolactone, multiple synthesis steps using ethylene oxide are required, which has economic disadvantages and results in 0% bio-content compared to using 3-hydroxypropionic acid.

[0004] On the other hand, in the case of polymerization using the synthesis of 3-hydroxypropionic acid, several steps are required to obtain poly(3-hydroxypropionic acid), including freeze-drying, sonication, and solvent extraction, and a large amount of solvent needs to be used. An attempt has been made to perform condensation polymerization of 3-hydroxypropionic acid to solve this problem, but there are limitations in obtaining high-molecular-weight poly(3-hydroxypropionic acid) due to by-products in the form of cyclic oligomers. Efforts to increase the molecular weight through ring-opening polymerization (ROP) of low-molecular-weight cyclic oligomers face challenges in separation and purification. Therefore, a method for preparing high-molecular-weight poly(3-hydroxypropionic acid) from 3-hydroxypropionic acid is needed.

[0005] In addition, polylactic acid (PLA) is a plant-derived resin obtained from plants such as corn, and it has attracted attention as an environmentally friendly material with excellent tensile strength, elasticity, and biodegradable properties. However, compared to conventional petroleum-based resins, it has limitations in impact resistance and heat resistance, which limits its scope of application. In addition, its elongation at break characteristics are poor, showing brittleness, which limits its use as a general-purpose resin.

[0006] To improve these drawbacks, copolymers containing other repeating units in polylactic acid are being studied, and particular attention is paid to 3-hydroxypropionic acid as a comonomer to improve elongation. In particular, poly(lactic acid-b-3-hydroxypropionic acid) block copolymers have attracted attention because they improve elongation characteristics while maintaining the inherent properties of polylactic acid.

[0007] However, biodegradable materials generally need to have a certain level of high molecular weight to have inherent mechanical properties, so it is necessary to prepare high molecular weight poly(lactic acid-b-3-hydroxypropionic acid) copolymers. During the polycondensation of 3-hydroxypropionic acid, low molecular weight cyclic structures are formed, making it impossible to produce high molecular weight poly(3-hydroxypropionic acid) and reducing the yield of poly(3-hydroxypropionic acid). Therefore, a method for preparing poly(lactic acid-b-3-hydroxypropionic acid) copolymers with high molecular weight and excellent mechanical properties is needed. Summary of the Invention

[0008] Technical Problem

[0009] The present invention provides a 3-hydroxypropionate (co)polymer composition and a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition, which have high molecular weight and exhibit excellent tensile strength, elastic modulus and elongation at break. The present invention also provides a method for preparing a 3-hydroxypropionate (co)polymer and a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer.

[0010] Technical Solution

[0011] According to one embodiment of the present invention, there is provided a 3-hydroxypropionate (co)polymer composition comprising a 3-hydroxypropionate (co)polymer and an isocyanate compound.

[0012] According to another embodiment of the present invention, there is provided a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition comprising a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer and an isocyanate compound.

[0013] According to still another embodiment of the present invention, there is provided a method for preparing a 3-hydroxypropionate (co)polymer, which comprises preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor; and introducing an isocyanate compound into the reactor to react with the 3-hydroxypropionate (co)polymer.

[0014] According to yet another embodiment of the present invention, there is provided a method for preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer, which comprises preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor; introducing an isocyanate compound into the reactor to react with the 3-hydroxypropionate (co)polymer; and preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer by ring-opening polymerization of a lactide monomer with the 3-hydroxypropionate (co)polymer.

[0015] Hereinafter, 3-hydroxypropionate (co)polymer compositions, poly(lactic acid-b-3-hydroxypropionic acid) block copolymer compositions, methods for preparing 3-hydroxypropionate (co)polymers, and methods for preparing poly(lactic acid-b-3-hydroxypropionic acid) block copolymers according to specific embodiments of the present invention will be described in more detail.

[0016] In addition, unless otherwise stated or in the case of special circumstances, the steps constituting the preparation methods described in this specification are not to be construed as limited to the order described in the specification. Accordingly, the order of the steps constituting the preparation methods can be changed within a range easily understood by those skilled in the art, and any obvious changes accompanying these are included within the scope of the present invention.

[0017] In addition, in this specification, terms such as first, second, etc. are used to describe various components, and these terms are only for the purpose of distinguishing one component from another.

[0018] In addition, in this specification, the term (co)polymer includes both copolymers and homopolymers.

[0019] In addition, unless otherwise stated, the weight-average molecular weight of polymers, copolymers, etc. can be measured using gel permeation chromatography (GPC). Specifically, the (co)polymer is dissolved in chloroform to a concentration of 2 mg / ml, and 20 μl is injected into the GPC, and GPC analysis is performed at 40°C. At this time, chloroform is used as the mobile phase for the GPC, the flow rate is 1.0 mL / min, and the columns used are two Agilent Mixed-B units connected in series. An RI detector is used as the detector. The value of Mw can be obtained using a calibration curve formed using polystyrene standard samples. Nine polystyrene standard samples with 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 are used.

[0020] In addition, in this specification, the term "substituted or unsubstituted" means unsubstituted or substituted by one or more substituents selected from the following: deuterium; halogen group; nitrile group; nitro group; hydroxyl group; carbonyl group; ester group; imide group; amino group; phosphine oxide group; alkoxy group; aryloxy group; alkylthioxy group; arylthioxy group; alkylsulfoxy; arylsulfoxy; silyl group; boron group; alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; aralkenyl group; alkaryl group; alkylamino group; aralkylamino group; heteroarylamino group; arylamino group; arylphosphine group; and heterocyclic group containing at least one of N, O, and S atoms, or unsubstituted or substituted by a substituent in which two or more of the above-exemplified substituents are linked. For example, the "substituent in which two or more substituents are linked" may be a biphenyl group. That is, a biphenyl group may be an aryl group, or it may be interpreted as a substituent in which two phenyl groups are linked.

[0021] In this specification, there is no particular limitation on the number of carbon atoms of the carbonyl group, but it is preferably 1 to 40. Specifically, the carbonyl group may be a compound having the following structural formula, but is not limited thereto.

[0022]

[0023] In this specification, the ester group may have a structure in which the oxygen of the ester group is substituted by a straight-chain, branched-chain or cyclic alkyl group having 1 to 25 carbon atoms or an aryl group having 6 to 25 carbon atoms. Specifically, the ester group may be a compound having the following structural formula, but is not limited thereto.

[0024]

[0025] In this specification, there is no particular limitation on the number of carbon atoms of the imide group, but it is preferably 1 to 25. Specifically, the imide group may be a compound having the following structural formula, but is not limited thereto.

[0026]

[0027] In this specification, silyl groups specifically include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc., but are not limited thereto.

[0028] In this specification, boron groups specifically include trimethylboron, triethylboron, tert-butyldimethylboron, triphenylboron, and phenylboron, but are not limited thereto.

[0029] In this specification, examples of the halogen group include fluorine, chlorine, bromine, or iodine.

[0030] In this specification, the alkyl group may be straight-chain or branched-chain, and there is no particular limitation on the number of carbon atoms, but it is preferably 1 to 40. According to one embodiment, the number of carbon atoms of the alkyl group is 1 to 20. According to another embodiment, the number of carbon atoms of the alkyl group is 1 to 10. According to still another embodiment, the number of carbon atoms of the alkyl group is 1 to 6. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, nonyl, 2,2-dimethylheptyl, 1-ethylpropyl, 1,1-dimethylpropyl, isohexyl, 4-methylhexyl, 5-methylhexyl, etc., but are not limited thereto.

[0031] In this specification, the alkenyl group may be straight-chain or branched-chain, and there is no particular limitation on the number of carbon atoms, but it is preferably 2 to 40. According to one embodiment, the number of carbon atoms of the alkenyl group is 2 to 20. According to another embodiment, the number of carbon atoms of the alkenyl group is 2 to 10. According to still another embodiment, the number of carbon atoms of the alkenyl group is 2 to 6. Specific examples thereof include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl, 1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-(naphthalen-1-yl)vinyl-1-yl, 2,2-bis(diphenyl-1-yl)vinyl-1-yl, stilbenyl, styryl, etc., but are not limited thereto.

[0032] In this specification, there is no particular limitation on the cycloalkyl group, but the number of carbon atoms is preferably 3 to 60. According to another embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 30. According to still another embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 20. According to yet another embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 6. Specific examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, etc., but are not limited thereto.

[0033] In the present specification, the aryl group is not particularly limited, but preferably has 6 to 60 carbon atoms, and it may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the aryl group has 6 to 30 carbon atoms. According to one embodiment, the aryl group has 6 to 20 carbon atoms. As the monocyclic aryl group, the aryl group may be a phenyl group, a biphenyl group, a terphenyl group, etc., but is not limited thereto. The polycyclic aryl group includes a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a chrysenyl group, a fluorenyl group, etc., but is not limited thereto.

[0034] In the present specification, the fluorenyl group may be substituted, and two substituents may be connected to each other to form a spiro ring structure. When the fluorenyl group is substituted, it may become compounds such as those below. However, it is not limited to these.

[0035]

[0036] In the present specification, the heteroaryl group is a heteroaryl group containing one or more of O, N, Si, and S as heteroatoms and also having aromaticity, and there is no particular limitation on its carbon number, but preferably it has 2 to 60 carbon atoms. Examples of the heteroaryl group include a thienyl group, a furyl group, a pyrrolyl group, an imidazolyl group, a thiazolyl group, an oxazolyl group, an oxadiazolyl group, a triazolyl group, a pyridyl group, a bipyridyl group, a pyrimidinyl group, a triazinyl group, an acridinyl group, a pyridazinyl group, a pyrazinyl group, a quinolinyl group, a quinazolinyl group, a quinoxalinyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an isoquinolinyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzimidazolyl group, a benzothiazolyl group, a benzocarbazolyl group, a benzothienyl group, a dibenzothienyl group, a benzofuryl group, a phenanthrolinyl group, a thiadiazolyl group, an isoxazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzothiazolyl group, a phenothiazinyl group, a dibenzofuryl group, etc., but is not limited thereto.

[0037] In the present specification, the aryl group in the aralkyl group, the aralkenyl group, the alkaryl group, and the arylamino group is the same as the examples of the aryl group defined above. In the present specification, the alkyl group in the aralkyl group, the alkaryl group, and the alkylamino group is the same as the examples of the alkyl group defined above. In the present specification, the heteroaryl group in the heteroarylamine can be applied to the description of the heteroaryl group defined above. In the present specification, the alkenyl group in the aralkenyl group is the same as the examples of the alkenyl group defined above. In the present specification, except that the arylene group is a divalent group, the description of the aryl group defined above can be applied. In the present specification, except that the heteroarylene group is a divalent group, the description of the heterocyclic group defined above can be applied. In the present specification, except that the hydrocarbon ring is not a monovalent group but is formed by combining two substituents, the description of the aryl group or the cycloalkyl group defined above can be applied. In the present specification, except that the heterocyclic ring is not a monovalent group but is formed by combining two substituents, the description of the heterocyclic group defined above can be applied.

[0038] In the present specification, represents a bond connected to another substituent.

[0039] According to one embodiment of the present invention, there is provided a 3-hydroxypropionate (co)polymer composition comprising a 3-hydroxypropionate (co)polymer and an isocyanate compound.

[0040] The present inventors completed the present invention by confirming that in the case of a 3-hydroxypropionate (co)polymer composition comprising a 3-hydroxypropionate (co)polymer and an isocyanate compound, it has a high molecular weight while having excellent mechanical properties such as tensile strength and elongation at break.

[0041] The 3-hydroxypropionate (co)polymer composition can be prepared by a 3-hydroxypropionate (co)polymer preparation method described later, but is not limited thereto.

[0042] The 3-hydroxypropionate (co)polymer contained in the composition is a 3-hydroxypropionate (co)polymer in which 3-hydroxypropionic acid is (co)polymerized, and the isocyanate contained in the composition can be a starting material that reacts with the 3-hydroxypropionate (co)polymer. In addition, the 3-hydroxypropionate (co)polymer can be a (co)polymer in which a 3-hydroxypropionate (co)polymer having (co)polymerized 3-hydroxypropionic acid has reacted with an isocyanate, and the isocyanate contained in the composition can be the one remaining after the reaction with the (co)polymer.

[0043] There is no particular limitation on the isocyanate as long as it is a compound containing one or more isocyanate groups, but for example, it can be one or more selected from hexamethylene diisocyanate, L-lysine ethyl ester diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, 1,5-naphthalene diisocyanate, and toluene diisocyanate.

[0044] In addition, 0.1 parts by weight or more and 10.0 parts by weight or less, 0.3 parts by weight or more and 9.0 parts by weight or less, 0.5 parts by weight or more and 8.0 parts by weight or less, 0.8 parts by weight or more and 7.0 parts by weight or less, 1.0 parts by weight or more and 5.0 parts by weight or less, or 1.5 parts by weight or more and 4.0 parts by weight or less of the isocyanate can be contained relative to the 3-hydroxypropionate (co)polymer. If the content of the isocyanate is too low relative to the 3-hydroxypropionate (co)polymer, the effect of increasing the molecular weight due to the isocyanate reaction may not occur, and if the content of the isocyanate is too high, the uniformity, quality, and processability of the product made of the finally prepared copolymer may be reduced.

[0045] In the 3-hydroxypropionate (co)polymer composition according to the above-described embodiments, the 3-hydroxypropionate (co)polymer may be a first 3-hydroxypropionate copolymer in which 3-hydroxypropionic acid is copolymerized with a diol.

[0046] The diol copolymerized with 3-hydroxypropionic acid is not limited to, but is preferably a diol having hydroxyl groups at both ends. For example, it may be one or more selected from 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,2-benzenediol, 1,3-benzenediol, 1,4-benzenediol, ethylene glycol, diethylene glycol, neopentyl glycol, and isosorbide. In addition, in order to increase the yield of the 3-hydroxypropionate copolymer and recover a high molecular weight copolymer, 1,4-butanediol is preferably used.

[0047] The content of the diol per 100 parts by weight of 3-hydroxypropionic acid may be 0.05 parts by weight or more and 5.00 parts by weight or less, 0.10 parts by weight or more and 4.50 parts by weight or less, 0.30 parts by weight or more and 4.00 parts by weight or less, 0.50 parts by weight or more and 3.50 parts by weight or less, 1.00 parts by weight or more and 3.40 parts by weight or less, 1.50 parts by weight or more and 3.30 parts by weight or less, or 2.00 parts by weight or more and 3.00 parts by weight or less. If the content of the diol relative to 3-hydroxypropionic acid is too low, the effect of increasing the copolymer molecular weight may not occur even when the isocyanate reacts in a subsequent step. If the content of the diol is too high, the molecular weight of the copolymer may actually be lower.

[0048] The first 3-hydroxypropionic acid copolymer prepared by copolymerizing 3-hydroxypropionic acid with a diol may have both ends substituted with hydroxyl groups, thereby enabling the preparation of a high molecular weight copolymer through a subsequent reaction with an isocyanate.

[0049] The first 3-hydroxypropionate copolymer may be represented by the following Chemical Formula 1.

[0050] [Chemical Formula 1]

[0051]

[0052] In Chemical Formula 1 above,

[0053] R1 is a substituted or unsubstituted C 1-20 alkylene; a substituted or unsubstituted C 6-60 arylene; or a substituted or unsubstituted C containing one or more heteroatoms selected from N, O, and S 2-60 heteroarylene,

[0054] n and m are each independently an integer from 5 to 1000.

[0055] For example, R1 can be a substituted or unsubstituted C 2-10 alkylene; or a substituted or unsubstituted C 6-20 arylene. More preferably, R1 can be ethylene, propylene, butylene, pentylene, hexylene, heptylene, phenylene, etc.

[0056] For example, n and m can each independently be an integer from 10 to 900, 50 to 800, 100 to 700, or 150 to 600.

[0057] In addition, the first 3-hydroxypropionate copolymer can have a weight-average molecular weight of more than 2,000 and less than 100,000, more than 5,000 and less than 80,000, more than 8,000 and less than 60,000, more than 10,000 and less than 40,000, more than 15,000 and less than 35,000, more than 15,000 and less than 30,000, more than 15,000 and less than 25,000, or more than 15,000 and less than 20,000.

[0058] Furthermore, the first 3-hydroxypropionate copolymer can have a number-average molecular weight of more than 2,000 and less than 15,000, more than 5,000 and less than 13,000, more than 7,000 and less than 11,000, or more than 8,000 and less than 10,000.

[0059] In addition, the first 3-hydroxypropionate copolymer can have a polydispersity index (PDI) of 1.0 or more and 3.5 or less, 1.2 or more and 3.0 or less, 1.4 or more and 2.5 or less, or 1.6 or more and 2.0 or less.

[0060] In addition, the 3-hydroxypropionate (co)polymer can be a second 3-hydroxypropionate copolymer, in which the first 3-hydroxypropionate copolymer copolymerized from 3-hydroxypropionic acid and diol has reacted with an isocyanate.

[0061] The hydroxyl groups at both ends of the first 3-hydroxypropionate copolymer can react with the isocyanate groups of the isocyanate to form a urethane bond to prepare the second 3-hydroxypropionate copolymer. Due to this chain growth reaction, the molecular weight of the second 3-hydroxypropionate copolymer can be significantly increased, thus preventing problems such as the formation of cyclic oligomer by-products that can reduce the molecular weight of the copolymer. In addition, compared with the first 3-hydroxypropionate copolymer, the second 3-hydroxypropionate copolymer can have a higher weight-average molecular weight and number-average molecular weight.

[0062] The second 3-hydroxypropionate copolymer can contain repeating units represented by the following Chemical Formula 2.

[0063] [Chemical Formula 2]

[0064]

[0065] In the above Chemical Formula 2,

[0066] R2 can be a single bond; a substituted or unsubstituted alkylene having 1 to 60 carbon atoms; a substituted or unsubstituted alkenylene having 1 to 60 carbon atoms; a substituted or unsubstituted arylene having 6 to 60 carbon atoms; or a substituted or unsubstituted heteroarylene having 2 to 60 carbon atoms containing one or more heteroatoms selected from N, O, S, and Si.

[0067] For example, R2 can be an ethyl ester-substituted or unsubstituted alkylene having 1 to 20 carbon atoms, an arylene having 6 to 20 carbon atoms, or a heteroarylene having 2 to 20 carbon atoms containing one or more heteroatoms selected from N, O, S, and Si. Additionally, R2 can be methylene, ethylene, 1,3-propylene, 1,2-propylene, 1,4-butylene, 1,3-butylene, 1,2-butylene, 1,5-pentylene, 1,4-pentylene, 1,3-pentylene, 1,2-pentylene, 1,6-hexylene, 1,5-hexylene, 1,4-hexylene, 1,3-hexylene, 1,2-hexylene, 1,7-heptylene, 1,6-heptylene, 1,5-heptylene, 1,4-heptylene, 1,3-heptylene, 1,2-heptylene, ethyl ester-substituted ethylene, ethyl ester-substituted propylene, ethyl ester-substituted butylene, ethyl ester-substituted pentylene, ethyl ester-substituted hexylene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 1,5-naphthylene, 1,6-naphthylene, 1,7-naphthylene, 1,8-naphthylene, benzylidene, 2,3-pyridylene, 2,4-pyridylene, 2,5-pyridylene, 2,6-pyridylene, 4,4'-methylenediphenylene, 3,3'-methylenediphenylene, 2,2'-methylenediphenylene, 2,4'-methylenediphenylene, 4,4'-ethylenediphenylene, 3,3'-ethylenediphenylene, 2,2'-ethylenediphenylene, or 2,4'-ethylenediphenylene.

[0068] In addition, in the above Chemical Formula 2, X and Y each independently represent the following Chemical Formula 2-1 or Chemical Formula 2-2, but at least one of them can be represented by the following Chemical Formula 2-1.

[0069] [Chemical Formula 2-1]

[0070]

[0071] In the above Chemical Formula 2-1,

[0072] R3 can be substituted or unsubstituted C1-20 Alkylene; substituted or unsubstituted C 6-60 Arylene; or substituted or unsubstituted C containing one or more heteroatoms selected from N, O and S 2-60 Heteroarylene.

[0073] For example, R3 can be substituted or unsubstituted C 2-10 Alkylene; or substituted or unsubstituted C 6-20 Arylene. More preferably, R1 can be ethylene, propylene, butylene, pentylene, hexylene, heptylene, phenylene, etc.

[0074] In addition, q and r can each independently be an integer from 5 to 1000. For example, q and r can each independently be an integer from 10 to 900, 50 to 800, 100 to 700, or 150 to 600.

[0075] [Chemical formula 2-2]

[0076]

[0077] In the above Chemical formula 2-2, p can be an integer from 5 to 1000. For example, p can be an integer from 10 to 900, 50 to 800, 100 to 700, or 150 to 600.

[0078] The end groups of the second 3-hydroxypropionate copolymer can be selected from the end groups represented by the following Chemical formula 3 to Chemical formula 5.

[0079] [Chemical formula 3]

[0080]

[0081] [Chemical formula 4]

[0082]

[0083] [Chemical formula 5]

[0084]

[0085] In the above Chemical formula 4,

[0086] R3 can be substituted or unsubstituted C 1-20 Alkylene; substituted or unsubstituted C 6-60 Arylene; or substituted or unsubstituted C containing one or more heteroatoms selected from N, O and S 2-60 Heteroarylene. R3 can be substituted or unsubstituted C 2-10 Alkylene; or substituted or unsubstituted C 6-20Arylene. More preferably, R1 may be ethylene, propylene, butylene, pentylene, hexylene, heptylene, phenylene, etc.

[0087] In addition, in Chemical Formulas 3 to 5, * may be a point each connected to the main chain or end group of the copolymer.

[0088] In addition, the second 3-hydroxypropionate copolymer may have an acid value of 100 meq / kg or less, 95 meq / kg or less, 90 meq / kg or less, 85 meq / kg or less, 80 meq / kg or less, 75 meq / kg or less, 1 meq / kg or more and 70 meq / kg or less, 2 meq / kg or more and 65 meq / kg or less, 3 meq / kg or more and 60 meq / kg or less, 4 meq / kg or more and 55 meq / kg or less, 5 meq / kg or more and 50 meq / kg or less, 7 meq / kg or more and 45 meq / kg or less, 8 meq / kg or more and 40 meq / kg or less, 10 meq / kg or more and 35 meq / kg or less, or 15 meq / kg or more and 30 meq / kg or less. Within this acid value range, the second 3-hydroxypropionate copolymer can exhibit a high molecular weight while also exhibiting excellent tensile strength, modulus, and elongation properties. The acid value can be measured by titration using a 0.02N potassium methoxide solution as the titrant.

[0089] In addition, the second 3-hydroxypropionate copolymer may have a weight-average molecular weight of 40,000 or more, 41,000 or more to 400,000 or less, 42,000 or more to 380,000 or less, or 43,000 or more to 350,000 or less.

[0090] In addition, the second 3-hydroxypropionate copolymer may have a number-average molecular weight of 15,000 or more, 16,000 or more to 200,000 or less, or 17,000 or more to 150,000 or less.

[0091] In addition, the second 3-hydroxypropionate copolymer may have a polydispersity index (PDI) of 1.5 or more and 7.0 or less, 2.0 or more and 6.5 or less, 2.3 or more and 6.0 or less, or 2.5 or more and 5.5 or less.

[0092] According to the above embodiments, the 3-hydroxypropionate (co)polymer composition may further comprise an oxazoline compound. Thus, the composition may comprise a 3-hydroxypropionate (co)polymer, an isocyanate, and an oxazoline.

[0093] The oxazoline can be a starting material that has reacted with a 3-hydroxypropionate (co)polymer, or it can be a residue remaining after reaction with the 3-hydroxypropionate (co)polymer.

[0094] There is no particular limitation on the oxazoline compound as long as it is a compound containing one or more oxazoline groups, and it can be, for example, one or more selected from the following: 1,3-phenylene bisoxazoline (2,2'-(1,3-phenylene)bis(2-oxazoline)), 1,4-phenylene bisoxazoline (2,2'-(1,4-phenylene)bis(2-oxazoline)), and 2,6-pyridylene bisoxazoline (2,2'-(2,6-pyridylene)-bis(2-oxazoline)).

[0095] In addition, per 100 parts by weight of the 3-hydroxypropionate (co)polymer, the oxazoline compound can be added in an amount of 0.001 parts by weight or more and 5.000 parts by weight or less, 0.005 parts by weight or more and 4.000 parts by weight or less, 0.010 parts by weight or more and 3.000 parts by weight or less, or 0.050 parts by weight or more and 2.500 parts by weight or less. If the amount of the oxazoline compound is too low compared to the 3-hydroxypropionate (co)polymer, the molecular weight of the (co)polymer may not increase. If the amount of the oxazoline compound is too high compared to the (co)polymer, by-products may be formed or a crosslinked structure may be formed.

[0096] In addition, the weight ratio of the oxazoline compound to the isocyanate compound can be 1:0.0001 to 1:10, 1:0.0010 to 1:8, 1:0.0020 to 1:6, 1:0.0050 to 1:5, 1:0.0100 to 1:4, 1:0.0500 to 1:3, or 1:0.1000 to 1:2. If the content of the isocyanate compound is too high relative to the oxazoline compound, crosslinking may occur before the molecular weight of the (co)polymer increases, making it difficult to prepare a high molecular weight (co)polymer. If the content of the isocyanate compound is too low relative to the oxazoline compound, it may be difficult to prepare a high molecular weight (co)polymer.

[0097] The 3-hydroxypropionate (co)polymer can be a (co)polymer that has reacted with an isocyanate and an oxazoline compound. The oxazoline compound can react with the functional group at the end of the repeating unit of poly(3-hydroxypropionic acid) to form two peptide bonds (-CONH-). The isocyanate compound can react with the functional group at the end of the repeating unit of poly(3-hydroxypropionic acid) to form two peptide bonds.

[0098] For example, the 3-hydroxypropionate (co)polymer can contain a repeating unit represented by the following Chemical Formula 6.

[0099] [Chemical Formula 6]

[0100]

[0101] In the above chemical formula 6,

[0102] R2 can be a single bond; a substituted or unsubstituted alkylene having 1 to 60 carbon atoms; a substituted or unsubstituted alkenylene having 1 to 60 carbon atoms; a substituted or unsubstituted arylene having 6 to 60 carbon atoms; or a substituted or unsubstituted heteroarylene having 2 to 60 carbon atoms containing one or more heteroatoms selected from N, O, S, and Si.

[0103] For example, R2 can be an ethyl ester-substituted or unsubstituted alkylene having 1 to 20 carbon atoms; an arylene having 6 to 20 carbon atoms; or a heteroarylene having 2 to 20 carbon atoms containing one or more heteroatoms selected from N, O, S, and Si. In addition, R2 can be methylene, ethylene, 1,3-propylene, 1,2-propylene, 1,4-butylene, 1,3-butylene, 1,2-butylene, 1,5-pentylene, 1,4-pentylene, 1,3-pentylene, 1,2-pentylene, 1,6-hexylene, 1,5-hexylene, 1,4-hexylene, 1,3-hexylene, 1,2-hexylene, 1,7-heptylene, 1,6-heptylene, 1,5-heptylene, 1,4-heptylene, 1,3-heptylene, 1,2-heptylene, ethyl ester-substituted ethylene, ethyl ester-substituted propylene, ethyl ester-substituted butylene, ethyl ester-substituted pentylene, ethyl ester-substituted hexylene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 1,5-naphthylene, 1,6-naphthylene, 1,7-naphthylene, 1,8-naphthylene, benzylidene, 2,3-pyridylene, 2,4-pyridylene, 2,5-pyridylene, 2,6-pyridylene, 4,4'-methylenediphenylene, 3,3'-methylenediphenylene, 2,2'-methylenediphenylene, 2,4'-methylenediphenylene, 4,4'-ethylenediphenylene, 3,3'-ethylenediphenylene, 2,2'-ethylenediphenylene, or 2,4'-ethylenediphenylene.

[0104] In addition, in the above chemical formula 2, A and B are each independently represented by the following chemical formula 6-1, chemical formula 6-2, or chemical formula 6-3, but at least one can be represented by the following chemical formula 6-1.

[0105] [Chemical formula 6-1]

[0106]

[0107] In the above chemical formula 6-1,

[0108] R4 can be a single bond; a substituted or unsubstituted alkylene having 1 to 60 carbon atoms; a substituted or unsubstituted alkenylene having 1 to 60 carbon atoms; a substituted or unsubstituted arylene having 6 to 60 carbon atoms; or a substituted or unsubstituted heteroarylene having 2 to 60 carbon atoms and containing one or more heteroatoms selected from N, O, S, and Si.

[0109] For example, R4 can be an ethyl ester-substituted or unsubstituted alkylene having 1 to 20 carbon atoms; an arylene having 6 to 20 carbon atoms; or a heteroarylene having 2 to 20 carbon atoms and containing one or more heteroatoms selected from N, O, S, and Si. In addition, R2 can be methylene, ethylene, 1,3-propylene, 1,2-propylene, 1,4-butylene, 1,3-butylene, 1,2-butylene, 1,5-pentylene, 1,4-pentylene, 1,3-pentylene, 1,2-pentylene, 1,6-hexylene, 1,5-hexylene, 1,4-hexylene, 1,3-hexylene, 1,2-hexylene, 1,7-heptylene, 1,6-heptylene, 1,5-heptylene, 1,4-heptylene, 1,3-heptylene, 1,2-heptylene, ethyl ester-substituted ethylene, ethyl ester-substituted propylene, ethyl ester-substituted butylene, ethyl ester-substituted pentylene, ethyl ester-substituted hexylene, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 1,5-naphthylene, 1,6-naphthylene, 1,7-naphthylene, 1,8-naphthylene, benzylidene, 2,3-pyridylene, 2,4-pyridylene, 2,5-pyridylene, 2,6-pyridylene, 4,4'-methylenediphenylene, 3,3'-methylenediphenylene, 2,2'-methylenediphenylene, 2,4'-methylenediphenylene, 4,4'-ethylenediphenylene, 3,3'-ethylenediphenylene, 2,2'-ethylenediphenylene, or 2,4'-ethylenediphenylene.

[0110] In addition, a and b can each independently be an integer from 10 to 5,000, such as an integer from 100 to 4,000, from 300 to 3,000, or from 500 to 1,000.

[0111] [Chemical formula 6-2]

[0112]

[0113] In the above Chemical formula 6-2,

[0114] R5 can be a substituted or unsubstituted C 1-20 alkylene; a substituted or unsubstituted C 6-60 arylene; or a substituted or unsubstituted C 2-60 heteroarylene containing one or more heteroatoms selected from N, O, and S.

[0115] For example, R5 can be a substituted or unsubstituted C 2-10 alkylene; or a substituted or unsubstituted C 6-20 arylene. More preferably, R5 can be ethylene, propylene, butylene, pentylene, hexylene, heptylene, phenylene, etc.

[0116] In addition, d and e can each independently be an integer from 5 to 1000. For example, d and e can each independently be an integer from 10 to 900, 50 to 800, 100 to 700, or 150 to 600.

[0117] d and e are each independently an integer from 5 to 1000.

[0118] [Chemical Formula 6-3]

[0119]

[0120] In the above Chemical Formula 6-3,

[0121] c can be an integer from 5 to 1000. For example, n and m can each independently be an integer from 10 to 900, 50 to 800, 100 to 700, or 150 to 600.

[0122] The 3-hydroxypropionate (co)polymer containing the repeating unit represented by the above Chemical Formula 6 can have end groups of the following Chemical Formulas 7 to 9.

[0123] [Chemical Formula 7]

[0124]

[0125] [Chemical Formula 8]

[0126]

[0127] [Chemical Formula 9]

[0128]

[0129] In the above Chemical Formula 8,

[0130] R4 can be a single bond; a substituted or unsubstituted alkylene having 1 to 60 carbon atoms; a substituted or unsubstituted alkenylene having 1 to 60 carbon atoms; a substituted or unsubstituted arylene having 6 to 60 carbon atoms; or a substituted or unsubstituted heteroarylene having 2 to 60 carbon atoms containing one or more heteroatoms selected from N, O, S, and Si.

[0131] In addition, in Chemical Formulas 7 to 9 above, * may be the point at which it is linked to the main chain or the end group of the copolymer.

[0132] In addition, the 3-hydroxypropionate (co)polymer containing the repeating unit represented by Chemical Formula 6 may have an acid value of 20 meq / kg or less, 0.1 meq / kg or more and 18 meq / kg or less, 0.2 meq / kg or more and 17 meq / kg or less, 0.3 meq / kg or more and 15 meq / kg or less, 0.4 meq / kg or more and 13 meq / kg or less, 0.5 meq / kg or more and 11 meq / kg or less, 0.7 meq / kg or more and 10 meq / kg or less, 0.8 meq / kg or more and 9 meq / kg or less, 1.0 meq / kg or more and 8 meq / kg or less, or 1.5 meq / kg or more and 5 meq / kg or less. Within this acid value range, the 3-hydroxypropionate (co)polymer can exhibit a high molecular weight while also exhibiting excellent tensile strength, modulus, and elongation properties. The acid value can be measured by titration using a 0.02N potassium methoxide solution as the titrant.

[0133] According to another embodiment of the present invention, there is provided a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition containing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer and an isocyanate compound.

[0134] The poly(lactic acid-b-3-hydroxypropionic acid) composition can be prepared by the poly(lactic acid-b-3-hydroxypropionic acid) preparation method described later, but is not limited thereto.

[0135] The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer can be a block copolymer in which lactide is ring-opening polymerized onto a second 3-hydroxypropionate copolymer formed by the reaction of an isocyanate with a first 3-hydroxypropionate copolymer (which is a copolymer of 3-hydroxypropionate and a diol). In addition, the isocyanate in the composition can be the residue remaining after the reaction with the first 3-hydroxypropionate copolymer.

[0136] In addition, the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition can further contain an oxazoline compound. Therefore, the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer can be a block copolymer in which lactide is ring-opening polymerized onto a 3-hydroxypropionate (co)polymer formed by the reaction of a 3-hydroxypropionate polymer, an isocyanate, and an oxazoline compound.

[0137] The above poly(lactic acid-b-3-hydroxypropionic acid) block copolymer may have a weight-average molecular weight of more than 120,000. More specifically, it may be 120,000 or more and 800,000 or less, 150,000 or more and 500,000 or less, 200,000 or more and 400,000 or less, or 220,000 or more and 300,000 or less. If the weight-average molecular weight of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is too small, the overall mechanical properties may be significantly reduced.

[0138] The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer may have a number-average molecular weight of 100,000 or more. More specifically, it may be 100,000 or more and 700,000 or less, 120,000 or more and 500,000 or less, 150,000 or more and 400,000 or less, or 200,000 or more and 300,000 or less.

[0139] The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer may have a polydispersity index of 2.0 or more and 10.0 or less, more specifically 2.5 or more, 3.0 or more, or 3.5 or more, and 8.0 or less, or 6.0 or less, or 5.0 or less.

[0140] The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer may have an elongation at break of 200% or more, 300% or more, 400% or more, 500% or more, 600% or more, and 1000% or less.

[0141] According to another embodiment of the present invention, a method for preparing a 3-hydroxypropionate (co)polymer is provided, which includes:

[0142] Preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor; and

[0143] Adding an isocyanate compound to the reactor to react with the 3-hydroxypropionate (co)polymer.

[0144] (Co)polymerization may be carried out under a sulfonic acid group catalyst. There is no particular limitation on the sulfonic acid group catalyst as long as it contains one or more sulfonic acid groups, but it may be, for example, p-toluenesulfonic acid, m-xylene-4-sulfonic acid, mesitylenesulfonic acid, or p-xylene-2-sulfonic acid. Based on 3-hydroxypropionic acid, the catalyst may be used in an amount of 0.01 mol% to 0.5 mol%.

[0145] The step of preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor may be a step of preparing a first 3-hydroxypropionate copolymer by copolymerizing a 3-hydroxypropionate with a diol.

[0146] The process for preparing the first 3-hydroxypropionate copolymer may include the step of preparing an oligomer by copolymerizing 3-hydroxypropionic acid with a diol (step 1) and the step of polymerizing the oligomer to prepare the 3-hydroxypropionate copolymer (step 2).

[0147] The polymerization reaction in step 1 may be a melt polymerization reaction, and melt polymerization means that the reactants 3-hydroxypropionic acid and diol and the product oligomer remain in a liquid state. Additionally, the polymerization reaction in step 1 may be carried out at a temperature above 50°C and below 150°C and a pressure above 1 torr and below 200 torr. For example, the reaction temperature in step 1 may be above 60°C, above 70°C, above 80°C, above 85°C, or above 90°C, and below 140°C, below 130°C, below 120°C, or below 110°C. Furthermore, step 1 may be carried out at a pressure above 2 torr, above 5 torr, above 10 torr, or above 15 torr, and below 150 torr, below 130 torr, below 110 torr, or below 100 torr. Additionally, the reaction time in step 1 may be appropriately considered in view of the molecular weight and yield of the prepared oligomer, and preferably, it may be carried out for 1 hour to 10 hours, 1.5 hours to 8 hours, or 2 hours to 5 hours.

[0148] The polymerization reaction in step 2 may also be a melt polymerization reaction, and it may be carried out at a temperature above 70°C and below 150°C. The reaction temperature in step 2 may be above 75°C, above 80°C, above 85°C, above 90°C, or above 95°C, and below 140°C, below 130°C, below 120°C, or below 110°C. Additionally, the pressure in step 2 may be above 2 torr, above 5 torr, above 10 torr, or above 15 torr, and below 150 torr, below 130 torr, below 110 torr, or below 100 torr. The reaction time in step 2 may be appropriately considered in view of the molecular weight and yield of the prepared polymer, and preferably, it may be carried out for 1 hour to 60 hours, 5 hours to 50 hours, 10 hours to 40 hours, or 15 hours to 30 hours.

[0149] Meanwhile, since step 2 is carried out after step 1, the catalyst added in step 1 may also participate in the reaction in step 2. Additionally, steps 1 and 2 may be carried out continuously.

[0150] Per 100 parts by weight of 3-hydroxypropionic acid, the first 3-hydroxypropionate copolymer may contain from more than 0.05 part by weight to 5.00 parts by weight, from more than 0.10 part by weight to 4.50 parts by weight, from more than 0.30 part by weight to 4.00 parts by weight, from more than 0.5 part by weight to 3.50 parts by weight, from more than 1.00 part by weight to 3.40 parts by weight, from more than 1.50 part by weight to 3.30 parts by weight, or from more than 2.00 parts by weight to 3.0 parts by weight of a diol. If the content of the diol is too low relative to 3-hydroxypropionic acid, even if the isocyanate reacts in a subsequent step, there may be no effect of increasing the molecular weight of the copolymer. If the content of the diol is too high, the molecular weight of the copolymer may actually be lower.

[0151] The step of introducing an isocyanate compound into a reactor and reacting it with a 3-hydroxypropionate (co)polymer may include a step of reacting a first 3-hydroxypropionate copolymer with an isocyanate to prepare a second 3-hydroxypropionate copolymer.

[0152] Meanwhile, there is no particular limitation on the timing of the reaction between the first 3-hydroxypropionate copolymer and the isocyanate. However, in order to prepare a high molecular weight copolymer, it is preferably reacted at the polymerization end point of the first 3-hydroxypropionate copolymer. For example, the isocyanate may be introduced into the reactor and reacted when the polymerization reaction has proceeded by more than 70%, more than 80%, more than 85%, more than 90%, more than 95%, or up to 100%. The timing of the reaction, that is, when the polymerization reaction has proceeded by more than 70%, can be derived from the conversion rate of 3-hydroxypropionic acid to the 3-hydroxypropionate copolymer. In addition, an ammeter or a nuclear magnetic resonance (NMR) device can be used to measure or confirm the conversion rate to the copolymer.

[0153] In addition, relative to the first 3-hydroxypropionate copolymer, the isocyanate may be from more than 0.1 part by weight to 10.0 parts by weight, from more than 0.3 part by weight to 9.0 parts by weight, from more than 0.5 part by weight to 8.0 parts by weight, from more than 0.8 part by weight to 7.0 parts by weight, from more than 1.0 part by weight to 5.0 parts by weight, or from more than 1.5 part by weight to 4.0 parts by weight. If the content of the isocyanate is too low relative to 3-hydroxypropionic acid, the effect of increasing the molecular weight due to the isocyanate reaction may not occur. If the content of the isocyanate is too high, the uniformity, quality, and processability of the product made from the final copolymer may be reduced due to the formation of a crosslinked structure.

[0154] The reaction with the isocyanate can be carried out at a temperature above 80 °C and below 180 °C for 5 minutes or more and 300 minutes or less. For example, the reaction with the isocyanate can be carried out at a temperature above 90 °C and below 170 °C, above 100 °C and below 160 °C, above 110 °C and below 150 °C, or above 120 °C and below 140 °C for a duration of 10 minutes or more and 280 minutes or less, 20 minutes or more and 260 minutes or less, 40 minutes or more and 240 minutes or less, 60 minutes or more and 220 minutes or less, or 90 minutes or more and 200 minutes or less.

[0155] The step of adding the isocyanate compound to the above reactor and reacting it with the 3-hydroxypropionate (co)polymer may include adding the oxazoline compound to the reactor and reacting it with the 3-hydroxypropionate (co)polymer.

[0156] As the oxazoline compound and the isocyanate compound are added to the reactor, they can react with the functional groups at the ends of the 3-hydroxypropionate (co)polymer. Thus, the ends of the 3-hydroxypropionate (co)polymer can be capped with the oxazoline compound and the isocyanate compound. In addition, by capping the ends of the 3-hydroxypropionate (co)polymer with the oxazoline compound and the isocyanate compound, the problem of molecular weight reduction caused by the formation of cyclic oligomer by-products can be prevented, thereby enabling the preparation of poly(3-hydroxypropionic acid) having a high molecular weight and excellent mechanical properties such as tensile strength and elongation at break.

[0157] Meanwhile, there is no particular limitation on the timing of adding the oxazoline compound and the isocyanate compound to the reactor, but it is preferably added at the end of the polymerization reaction of the 3-hydroxypropionate (co)polymer to prepare a high molecular weight 3-hydroxypropionate (co)polymer. For example, the oxazoline compound and the isocyanate compound can be added when the polymerization reaction has proceeded by 70% or more, 80% or more, 85% or more, 90% or more, 95% or more, up to 100% or less. The timing of adding the oxazoline compound and the isocyanate compound, i.e., when the polymerization reaction has proceeded by 70% or more, can be derived from the conversion rate of 3-hydroxypropionic acid to the 3-hydroxypropionate (co)polymer. Additionally, an ammeter or a nuclear magnetic resonance (NMR) apparatus can be used to measure or confirm the conversion rate to the 3-hydroxypropionate (co)polymer.

[0158] Furthermore, the step of adding the oxazoline compound and the isocyanate compound to the reactor may involve first adding the oxazoline compound to the reactor and then adding the isocyanate compound. For example, the oxazoline compound can be added to the reactor and stirred for 30 minutes or more and 6 hours or less, 1 hour or more and 5 hours or less, or 2 hours or more and 4 hours or less, and then the isocyanate compound can be added.

[0159] In addition, per 100 parts by weight of the 3-hydroxypropionate (co)polymer, the oxazoline compound can be added in an amount of 0.001 parts by weight or more and 5.000 parts by weight or less, 0.005 parts by weight or more and 4.000 parts by weight or less, 0.010 parts by weight or more and 3.000 parts by weight or less, or 0.050 parts by weight or more and 2.500 parts by weight or less. If the amount of the oxazoline compound added is too low compared to the 3-hydroxypropionate (co)polymer, the molecular weight of the 3-hydroxypropionate (co)polymer may not increase. If the amount of the oxazoline compound added is too high compared to the 3-hydroxypropionate (co)polymer, by-products may be produced or a crosslinked structure may be formed.

[0160] Furthermore, per 100 parts by weight of the 3-hydroxypropionate (co)polymer, the isocyanate compound can be added in an amount of 0.001 parts by weight or more and 5.000 parts by weight or less, 0.005 parts by weight or more and 4.500 parts by weight or less, 0.010 parts by weight or more and 4.000 parts by weight or less, 0.050 parts by weight or more and 3.500 parts by weight or less, 0.100 parts by weight or more and 3.400 parts by weight or less, 0.200 parts by weight or more and 3.300 parts by weight or less, or 0.300 parts by weight or more and 3.200 parts by weight or less. If the amount of the isocyanate compound added is too low compared to the 3-hydroxypropionate (co)polymer, crystallization of the polymer may occur slowly, resulting in poor mechanical properties such as tensile properties. If the amount of the isocyanate compound added is too high compared to the 3-hydroxypropionate (co)polymer, crosslinking may occur before the molecular weight of the polymer increases, making it difficult to prepare a high molecular weight polymer.

[0161] According to another embodiment of the present invention, there is provided a method for preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer, which comprises:

[0162] Preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor;

[0163] Adding an isocyanate compound to the reactor and reacting it with the 3-hydroxypropionate (co)polymer; and

[0164] Preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer by ring-opening polymerization of a lactide monomer onto the 3-hydroxypropionate (co)polymer.

[0165] The step of preparing the 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor and adding an isocyanate compound to the reactor and reacting it with the 3-hydroxypropionate (co)polymer is as described above in the method for preparing the 3-hydroxypropionate (co)polymer according to another embodiment.

[0166] For example, the step of preparing the 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor can be the step of preparing a first 3-hydroxypropionate copolymer by copolymerizing 3-hydroxypropionate with a diol.

[0167] In addition, an oxazoline compound can be further added to the reactor to react with the 3-hydroxypropionate (co)polymer.

[0168] The preparation of the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer by ring-opening polymerization of lactide monomers onto the 3-hydroxypropionate (co)polymer can be carried out in the presence of a lactide ring-opening catalyst.

[0169] The ring-opening polymerization can be carried out under one or more catalysts selected from organometallic complex catalysts and organic catalysts. For example, the organometallic complex catalyst can be a catalyst represented by the following Chemical Formula 10.

[0170] [Chemical Formula 10]

[0171] MA 1 p A 2 2-p

[0172] In Chemical Formula 10,

[0173] M is Al, Mg, Zn, Ca, Sn, Fe, Y, Sm, Lu, Ti or Zr,

[0174] p is an integer from 0 to 2,

[0175] A 1 and A 2 are each independently an alkoxy group or a carboxyl group.

[0176] More specifically, the catalyst can be tin(II) 2-ethylhexanoate (Sn(Oct)2; also referred to as stannous octoate hereinafter).

[0177] Meanwhile, if an organic catalyst is generally used for preparing a polylactide resin by ring-opening polymerization of lactide monomers, the organic catalyst can generally be used without limitation in terms of its composition. For example, the organic catalyst can be selected from 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 4-dimethylaminopyridine (DMAP), 4-(1-pyrrolidinyl)pyridine (PPY), imidazole, triazolium, thiourea, tertiary amines, and creatinine.

[0178] Based on 100 mol% of the lactide monomers, the content of the catalyst can be 0.0001 mol% to 10 mol%, 0.005 mol% to 8 mol%, 0.05 mol% to 5 mol%, or 0.09 mol% to 3 mol%. If the content of the catalyst is too low relative to 100 mol% of the lactide monomers, the polymerization activity may be insufficient. If the content of the catalyst is too high, the amount of residual catalyst in the prepared block copolymer may increase, resulting in the decomposition of the copolymer due to depolymerization such as transesterification reactions or a decrease in molecular weight. Additionally, the ring-opening polymerization can be carried out at a temperature of 150°C to 200°C, 160°C to 190°C, or 170°C to 180°C, and can be carried out for 5 minutes to 24 hours, 30 minutes to 20 hours, 1 hour to 15 hours, or 2 hours to 10 hours.

[0179] In the block copolymer, the weight ratio of lactide to 3-hydroxypropionate (co)polymer can be 99:1 to 50:50, 98:2 to 55:45, 97:3 to 60:40, 96:4 to 70:30, or 95:5 to 80:20. If the content of the 3-hydroxypropionate (co)polymer is too small relative to lactide, the brittleness may increase. If the content of the 3-hydroxypropionate (co)polymer is too large relative to lactide, the molecular weight may decrease, potentially reducing the processing performance and thermal stability.

[0180] Beneficial Effects

[0181] As described above, the present invention can provide a 3-hydroxypropionate (co)polymer composition and a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition having high molecular weight and excellent tensile strength, modulus, and elongation. The present invention can also provide a method for preparing such a 3-hydroxypropionate (co)polymer and a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer. Detailed Description

[0182] In the following, embodiments of the present disclosure will be explained in detail with reference to examples. However, the following examples are for illustrative purposes only, and the detailed description of the present disclosure is not limited to these examples.

[0183] Example 1

[0184] 60 g of 3-hydroxypropionic acid and 0.42 g (1 mol%) of 1,4-butanediol were added to an oil bath and reacted at 90 °C and 100 Torr for 2 hours. Then, 176 mg of p-toluenesulfonic acid (p-TSA) catalyst was added to the oil bath. The reaction was carried out under reduced pressure at 20 Torr for 2 hours, followed by a polymerization reaction at below 1 Torr for 24 hours to prepare a copolymer. After the reaction was completed, the reaction product was dissolved in chloroform at a ratio of 10 g / 50 mL and extracted with 500 mL of methanol to obtain the copolymer, which was then dried under vacuum for 12 hours.

[0185] Subsequently, 20 g of the copolymer was added to an oil bath under a nitrogen atmosphere, and 0.19 ml of hexamethylene diisocyanate was added. The mixture was stirred and reacted at 140 °C for 180 minutes to prepare a 3-hydroxypropionate copolymer.

[0186] Example 2

[0187] A 3-hydroxypropionate copolymer was prepared in the same manner as in Example 1, except that 0.26 ml of hexamethylene diisocyanate was used instead of 0.19 ml of hexamethylene diisocyanate.

[0188] Example 3

[0189] A 3-hydroxypropionate copolymer was prepared in the same manner as in Example 1, except that 0.34 ml of hexamethylene diisocyanate was used instead of 0.19 ml of hexamethylene diisocyanate.

[0190] Example 4

[0191] A 3-hydroxypropionate copolymer was prepared in the same manner as in Example 1, except that 0.39 ml of hexamethylene diisocyanate was added and stirred and reacted for 90 minutes, instead of adding 0.19 ml of hexamethylene diisocyanate and stirring and reacting for 180 minutes.

[0192] Example 5

[0193] A 3-hydroxypropionate copolymer was prepared in the same manner as in Example 1, except that 0.42 ml of hexamethylene diisocyanate was added and stirred and reacted for 90 minutes, instead of adding 0.19 ml of hexamethylene diisocyanate and stirring and reacting for 180 minutes.

[0194] Example 6

[0195] A 3-hydroxypropionate copolymer was prepared in the same manner as in Example 1, except that 0.48 ml of hexamethylene diisocyanate was added and stirred and reacted at 120 °C for 120 minutes, instead of adding 0.19 ml of hexamethylene diisocyanate and stirring and reacting at 140 °C for 180 minutes.

[0196] Example 7

[0197] 100 ml of a 60% aqueous solution of 3-hydroxypropionic acid was added to a 100 ml Schlenk flask, and about 60% of the water in 3-hydroxypropionic acid was removed at 90 °C and 100 Torr over 2 hours. Then, 0.2112 parts by weight of p-toluenesulfonic acid (p-TSA) catalyst per 100 parts by weight of 3-hydroxypropionic acid was added to the reaction flask, and melt polycondensation reaction was carried out at 90 °C and 1 Torr for 24 hours. After the reaction was completed, the reaction product was dissolved in chloroform at a ratio of 10 g / 50 mL, and extracted with 500 mL of methanol to obtain poly(3-hydroxypropionic acid).

[0198] Subsequently, 10 g of poly(3-hydroxypropionic acid) was added to a 100 ml Schlenk flask and dried at 40 °C for 12 hours. Then, 0.234 g of 1,3-phenylene bisoxazoline was added and stirred at 160 °C for 2 hours. After that, 0.053 g of hexamethylene diisocyanate was added and stirred at 100 °C for 90 minutes.

[0199] Example 8

[0200] Poly(3-hydroxypropionic acid) was prepared in the same manner as in Example 7, except that 0.071 g of L-lysine ethyl ester diisocyanate was used instead of 0.053 g of hexamethylene diisocyanate.

[0201] Example 9

[0202] Poly(3-hydroxypropionic acid) was prepared in the same manner as in Example 7, except that 0.142 g of L-lysine ethyl ester diisocyanate was used instead of 0.053 g of hexamethylene diisocyanate.

[0203] Example 10

[0204] Poly(3-hydroxypropionic acid) was prepared in the same manner as in Example 7, except that 0.310 g of L-lysine ethyl ester diisocyanate was used instead of 0.053 g of hexamethylene diisocyanate.

[0205] Comparative Example 1

[0206] 60 g of 3-hydroxypropionic acid was added to an oil bath and reacted at 90 °C and 100 Torr for 2 hours. Then, 176 mg of p-toluenesulfonic acid (p-TSA) catalyst was added to the oil bath. The mixture was reacted under reduced pressure at 20 Torr for 2 hours and polymerized at less than 1 Torr for 24 hours to prepare a polymer. After the reaction was completed, the reaction mixture was dissolved in chloroform at a ratio of 10 g / 50 mL and extracted with 500 mL of methanol to obtain the polymer, which was then dried under vacuum for 12 hours.

[0207] Subsequently, 20 g of the polymer was added to an oil bath under a nitrogen atmosphere, and 0.12 ml of hexamethylene diisocyanate was added. The mixture was stirred and reacted at 140 °C for 180 minutes to prepare a 3-hydroxypropionate polymer.

[0208] Comparative Example 2

[0209] A 3-hydroxypropionate polymer was prepared in the same manner as in Comparative Example 1, except that 0.28 ml of hexamethylene diisocyanate was used instead of 0.12 ml of hexamethylene diisocyanate.

[0210] Comparative Example 3

[0211] 3475 g of 3-hydroxypropionic acid was added to an oil bath and reacted at 90 °C and 100 Torr for 2 hours. Then, 14.7 g of p-toluenesulfonic acid (p-TSA) catalyst was added to the oil bath. The mixture was reacted under reduced pressure at 20 Torr for 2 hours and polymerized at less than 1 Torr for 24 hours to prepare a 3-hydroxypropionic acid polymer. After the reaction was completed, the reaction mixture was dissolved in chloroform at a ratio of 10 g / 50 mL and extracted with 500 mL of methanol to obtain the polymer, which was then dried under vacuum for 12 hours to recover the 3-hydroxypropionic acid polymer.

[0212] Comparative Example 4

[0213] 3475 g of 3-hydroxypropionic acid and 34.8 g of 1,4-butanediol were added to an oil bath and reacted at 90 °C and 100 Torr for 2 hours. Then, 14.7 g of p-toluenesulfonic acid (p-TSA) catalyst was added to the oil bath. The mixture was reacted under reduced pressure at 20 Torr for 2 hours and copolymerized at less than 1 Torr for 24 hours to prepare a copolymer. After the reaction was completed, the reaction mixture was dissolved in chloroform at a ratio of 10 g / 50 mL and extracted with 500 mL of methanol to obtain the copolymer, which was then dried under vacuum for 12 hours to recover the copolymer.

[0214] Comparative Example 5

[0215] Poly(3-hydroxypropionic acid) was prepared in the same manner as in Example 1, except that 0.234 g of 1,3-phenylenebisoxazoline and 0.053 g of hexamethylene diisocyanate were not used.

[0216] Comparative Example 6

[0217] Poly(3-hydroxypropionic acid) was prepared in the same manner as in Example 7, except that 0.053 g of hexamethylene diisocyanate was not used.

[0218] Experimental Example

[0219] The physical properties of the polymers prepared in the above Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Table 1 below.

[0220] 1. Molecular weight measurement

[0221] The weight-average molecular weight (Mw), number-average molecular weight (Mn), peak molecular weight (Mp), and polydispersity index (PDI) of the (co)polymers of the Examples and Comparative Examples were measured by gel permeation chromatography (GPC: gel permeation chromatography, Waters Alliancee2695).

[0222] - Solvent: chloroform (eluent)

[0223] - Flow rate: 1.0 ml / min

[0224] - Column temperature: 35 °C

[0225] - Standard: polystyrene

[0226] 2. Measurement of tensile strength, modulus, and elongation

[0227] Using a hot press (Limotem QM900S), dog bone membrane specimens were prepared from the (co)polymers of the Examples and Comparative Examples at 90 °C according to ASTM D 882 standard, and the thickness was controlled as described in Table 1 below. In addition, the tensile strength, modulus, and elongation of the specimens were measured using a universal testing machine (Zwick).

[0228] [Table 1]

[0229]

[0230]

[0231] Referring to Table 1 above, it was confirmed that Examples 1 to 10 had higher molecular weights and also exhibited excellent tensile strength and elongation compared to Comparative Examples 1 to 6.

Claims

1. A 3-hydroxypropionate (co)polymer composition comprising a 3-hydroxypropionate (co)polymer and an isocyanate compound.

2. The 3-hydroxypropionate (co)polymer composition according to claim 1, Among them, wherein based on the 3-hydroxypropionate (co)polymer, the content of the isocyanate compound is 0.1 part by weight or more and 10.0 parts by weight or less.

3. The 3-hydroxypropionate (co)polymer composition according to claim 1, Among them, wherein the 3-hydroxypropionate (co)polymer is a first 3-hydroxypropionate copolymer in which 3-hydroxypropionic acid is copolymerized with a diol.

4. The 3-hydroxypropionate (co)polymer composition according to claim 3, Among them, wherein both ends of the first 3-hydroxypropionate copolymer are substituted with hydroxyl groups.

5. The 3-hydroxypropionate (co)polymer composition according to claim 1, Among them, wherein the 3-hydroxypropionate (co)polymer is a second 3-hydroxypropionate copolymer in which a first 3-hydroxypropionate copolymer in which 3-hydroxypropionic acid is copolymerized with a diol has been reacted with an isocyanate.

6. The 3-hydroxypropionate (co)polymer composition according to claim 5, Among them, wherein the second 3-hydroxypropionate copolymer contains a repeating unit represented by the following formula 2: [Formula 2] wherein in Formula 2, R2 is a single bond; a substituted or unsubstituted alkylene group having 1 to 60 carbon atoms; a substituted or unsubstituted alkenylene group having 1 to 60 carbon atoms; a substituted or unsubstituted arylene group having 6 to 60 carbon atoms; or a substituted or unsubstituted heteroarylene group having 2 to 60 carbon atoms containing at least one heteroatom selected from N, O, S, and Si, X and Y are each independently represented by Formula 2-1 or Formula 2-2, but at least one is represented by Formula 2-1, [Formula 2-1] wherein in Formula 2-1, R3 is a substituted or unsubstituted C 1-20 alkylene; a substituted or unsubstituted C 6-60 arylene; or a substituted or unsubstituted C containing at least one heteroatom selected from N, O, and S 2-60 heteroarylene, q and r are each independently an integer from 5 to 1000, [Formula 2-2] wherein in Formula 2-2, p is an integer from 5 to 1000.

7. The 3-hydroxypropionate (co)polymer composition according to claim 1, further comprising an oxazoline compound.

8. The 3-hydroxypropionate (co)polymer composition according to claim 7, Among them, wherein the weight ratio of the oxazoline compound to the isocyanate compound is 1:0.0001 to 1:

10.

9. The 3-hydroxypropionate (co)polymer composition according to claim 7, Among them, wherein the 3-hydroxypropionate (co)polymer contains a repeating unit represented by the following formula 6: [Formula 6] R2 is a single bond; a substituted or unsubstituted alkylene group having 1 to 60 carbon atoms; a substituted or unsubstituted alkenylene group having 1 to 60 carbon atoms; a substituted or unsubstituted arylene group having 6 to 60 carbon atoms; or a substituted or unsubstituted heteroarylene group having 2 to 60 carbon atoms containing at least one heteroatom selected from N, O, S, and Si, A and B are each independently represented by the following Formula 6-1, Formula 6-2, or Formula 6-3, but at least one is represented by the following Formula 6-1, [Formula 6-1] wherein in Formula 6-1, R4 is a single bond; a substituted or unsubstituted alkylene having 1 to 60 carbon atoms; a substituted or unsubstituted alkenylene having 1 to 60 carbon atoms; a substituted or unsubstituted arylene having 6 to 60 carbon atoms; or a substituted or unsubstituted heteroarylene having 2 to 60 carbon atoms containing at least one heteroatom selected from N, O, S, and Si, a and b are each independently an integer from 10 to 5,000; [Formula 6-2] wherein, in Formula 6-2, R5 is a substituted or unsubstituted C 1-20 alkylene; a substituted or unsubstituted C 6-60 arylene; or a substituted or unsubstituted C containing one or more heteroatoms selected from N, O and S 2-60 heteroarylene, d and e are each independently an integer from 5 to 1,000; [Formula 6-3] wherein, in Formula 6-3, c is an integer from 5 to 1,000.

10. A poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition comprising a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer and an isocyanate compound.

11. The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition according to claim 10, Among them, wherein the poly(lactic acid-b-3-hydroxypropionic acid) block copolymer is a block copolymer in which lactide is ring-opening polymerized onto a second 3-hydroxypropionate copolymer, and the second 3-hydroxypropionate copolymer is formed by reacting a first 3-hydroxypropionate copolymer obtained by copolymerizing 3-hydroxypropionic acid with a diol with an isocyanate.

12. The poly(lactic acid-b-3-hydroxypropionic acid) block copolymer composition according to claim 10, further comprising an oxazoline compound.

13. A method for preparing a 3-hydroxypropionate (co)polymer, comprising: preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor; and adding an isocyanate compound to the reactor to react with the 3-hydroxypropionate (co)polymer.

14. The method for preparing a 3-hydroxypropionate (co)polymer according to claim 13, Among them, wherein the (co)polymerization is carried out under a sulfonic acid catalyst.

15. The method for preparing a 3-hydroxypropionate (co)polymer according to claim 13, Among them, wherein the reaction with the isocyanate is carried out at a temperature above 80°C and below 180°C for a time of more than 5 minutes and less than 300 minutes.

16. The method for preparing a 3-hydroxypropionate (co)polymer according to claim 13, Among them, wherein the preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor is preparing a first 3-hydroxypropionate copolymer by copolymerizing the 3-hydroxypropionate with a diol.

17. The method for preparing a 3-hydroxypropionate (co)polymer according to claim 16, Among them, wherein for every 100 parts by weight of the 3-hydroxypropionic acid, the first 3-hydroxypropionate copolymer contains 0.05 parts by weight or more and 5.00 parts by weight or less of the diol.

18. The method for preparing a 3-hydroxypropionate (co)polymer according to claim 13, further comprising adding an oxazoline compound to the reactor to react with the 3-hydroxypropionate (co)polymer.

19. The method for preparing a 3-hydroxypropionate (co)polymer according to claim 18, Among them, Per 100 parts by weight of poly(3-hydroxypropionic acid), the oxazoline compound and the isocyanate compound are each independently added in an amount of 0.001 part by weight or more and 5.000 parts by weight or less.

20. The method for preparing a 3-hydroxypropionate (co)polymer according to claim 18, Among them, The isocyanate compound is added to the reactor after adding the oxazoline compound.

21. A method for preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer, comprising: Preparing a 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor; Adding an isocyanate compound to the reactor to react with the 3-hydroxypropionate (co)polymer; and Preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer by ring-opening polymerization of a lactide monomer to the 3-hydroxypropionate (co)polymer.

22. The method for preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer according to claim 21, Among them, The preparing of the 3-hydroxypropionate (co)polymer by (co)polymerizing 3-hydroxypropionic acid in a reactor is to prepare a first 3-hydroxypropionate copolymer by copolymerizing the 3-hydroxypropionate with a diol.

23. The method for preparing a poly(lactic acid-b-3-hydroxypropionic acid) block copolymer according to claim 21, Further comprising adding an oxazoline compound to the reactor to react with the 3-hydroxypropionate (co)polymer.

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