Biodegradable polyesteramide copolymer, preparation method therefor, and biodegradable film comprising same

Abstract

The present disclosure relates to a biodegradable polyesteramide copolymer, a preparation method therefor, and a biodegradable film comprising the copolymer. When utilized as a biodegradable film, the copolymer according to an embodiment provides improved adhesion and biodegradability, and a tactile feel similar to that of commercial leather products, and thus can be utilized as an environmentally friendly coating material.

Description

Biodegradable polyesteramide copolymer, method for manufacturing the same, and biodegradable film comprising the same

[0001] The present disclosure relates to a biodegradable polyesteramide copolymer, a method for manufacturing the same, and a biodegradable film comprising said copolymer.

[0002]

[0003] Recently, consumer ethical awareness regarding environmental pollution caused by toxic waste and excessive water usage during the natural leather manufacturing process, as well as animal welfare issues associated with natural leather consumption, has rapidly increased. As a result, interest in synthetic leather—specifically vegan leather—as a substitute for natural leather is surging in industries producing clothing, shoes, bags, luggage, home coverings, and car seats.

[0004] Conventionally, synthetic leather is generally manufactured by synthesizing thermoplastic polyurethane (TPU) and polyvinyl chloride (PVC) and coating the synthesized polymers onto fabrics such as cotton. However, synthetic leather produced using TPU and PVC has disadvantages, such as the use of petroleum-based raw materials and the emission of substances harmful to the environment due to toxic waste generated during the production process and after use. Therefore, to address these issues, there is a need for research on the development of vegan leather coated products that possess thermal and mechanical properties similar to or superior to conventional synthetic or natural leather, while also being biomass-based and biodegradable.

[0005]

[0006] One embodiment aims to provide a biodegradable polyesteramide copolymer.

[0007] Another embodiment aims to provide a method for manufacturing the copolymer.

[0008] Another embodiment aims to provide a composition for forming a biodegradable coating layer comprising the copolymer.

[0009] Another embodiment aims to provide a biodegradable film comprising a coating layer formed from the above-described composition for forming a biodegradable coating layer.

[0010] Another embodiment aims to provide a biodegradable leather product comprising the above-mentioned biodegradable film.

[0011]

[0012] One embodiment provides a polyesteramide copolymer represented by the following chemical formula 1.

[0013] [Chemical Formula 1]

[0014]

[0015] In the above chemical formula 1, L 1 to L 4 Each is independently a (C1-C7)alkylene group; and m / n is 0.1 or more and 10 or less.

[0016] In one embodiment, the L 1 to L 4 Each can independently be a (C3-C5)alkylene group.

[0017] In one embodiment, the m / n may be 1 or more and 9 or less.

[0018] In one embodiment, the polyesteramide copolymer may be a polyesteramide copolymer comprising a copolymer represented by the following chemical formula 2.

[0019] [Chemical Formula 2]

[0020]

[0021] In the above chemical formula 2, m / n may be 1 or more and 9 or less.

[0022] In one embodiment, the melting point (Tm) of the polyesteramide copolymer may be 60°C or higher and 200°C or lower.

[0023] Another embodiment provides a method for preparing a polyesteramide copolymer represented by Formula 1, comprising: (a) a step of obtaining a polyamide salt by reacting a compound represented by Formulas 3 and 4 below; and (b) a step of obtaining a polyesteramide oligomer by reacting the polyamide salt obtained in (a) with a compound represented by Formulas 5 and 6 below.

[0024] [Chemical Formula 1]

[0025]

[0026] [Chemical Formula 3]

[0027]

[0028] [Chemical Formula 4]

[0029]

[0030] [Chemical Formula 5]

[0031]

[0032] [Chemical Formula 6]

[0033]

[0034] In the above Chemical Formula 1 and Chemical Formulas 3 to 6, L 1 to L 4 Each is independently a (C1-C7)alkylene group; and m / n is 0.1 or more and 10 or less.

[0035] In one embodiment, the L 1 to L 4 Each can independently be a (C3-C5)alkylene group.

[0036] In one embodiment, the m / n may be 1 or more and 9 or less.

[0037] In one embodiment, the compounds represented by Formula 3 and Formula 4 are included in an amount of 1 to 50 mol% relative to the total molar amount of compounds represented by Formulas 3 to 6, and the compound represented by Formula 5 may be included in an amount of 50 to 99 mol% relative to the total molar amount of compounds represented by Formulas 3 to 6.

[0038] In one embodiment, after step (b), the method may further include step (c) of polycondensing the polyesteramide oligomer to obtain a polyesteramide copolymer.

[0039] Another embodiment provides a composition for forming a biodegradable coating layer comprising the above-mentioned polyesteramide copolymer.

[0040] Another embodiment provides a biodegradable film comprising: a substrate layer; and a coating layer formed from a composition for forming a biodegradable coating layer and positioned on at least one surface of the substrate layer.

[0041] In one embodiment, the surface energy of the biodegradable film according to ASTM D7490 may be 40 mN / m or more.

[0042] In one embodiment, the measured 12-week composting decomposition rate of the biodegradable film may be 50% or more.

[0043] In one embodiment, the adhesive strength of the biodegradable film measured according to test method B of ASTM D 3359 may be 3B or higher.

[0044] In one embodiment, the static friction coefficient (μ) of the biodegradable film and commercial leather measured by a friction and wear tester (Heidon tribogear, 94i-II, Japan) s The difference may be within ±0.1.

[0045] In one embodiment, the substrate layer is polylactic acid (PLA), polypropylene (PP), polyethylene (PE), polyvinyl alcohol (PVA), polyhydroxyalkanoates (PHA), polyethylene terephthalate (PET), poly(caprolactone) (PL), poly(glycolic acid) (PGA), poly(lactidecaprolactone) (PLCL), polybutylene succinate (PBS), polybutylene adipate-co-terephthalate (PBAT), poly(lactic-co-glycolic acid) (PLGA), polyhydroxyalkanoates (PHA), plant-derived It may include one or more biodegradable polymers selected from the group consisting of natural polymers and animal-derived polymers.

[0046] Another embodiment provides a biodegradable leather product comprising the above-mentioned biodegradable film.

[0047] The present disclosure relates to a biodegradable polyesteramide copolymer, a method for manufacturing the same, and a biodegradable film comprising said copolymer. A copolymer according to one embodiment is synthesized from a dicarboxylic acid with a relatively short carbon chain, and thus the hydrogen bonding force is strengthened; consequently, a biodegradable film comprising the same has improved adhesion compared to existing commercial leather products. Furthermore, a biodegradable film comprising a copolymer according to one embodiment has a tactile feel similar to commercial leather products and has higher biodegradability than commercial leather products, so it can be utilized as an eco-friendly coating material.

[0048]

[0049] Since the embodiments described in this specification may be modified in various different forms, the technology according to one embodiment is not limited to the embodiments described below. Furthermore, throughout the specification, the terms "comprising," "including," "containing," "containing," or "having" any component do not exclude other components but may include additional components unless specifically stated otherwise, and do not exclude elements, materials, or processes not additionally listed.

[0050] The numerical ranges used herein include lower and upper limits and all values ​​within those ranges, increments logically derived from the form and width of the defined ranges, all of which are limited, and all possible combinations of upper and lower limits of numerical ranges limited in different forms. For example, if the content of the composition is limited to 10% to 80% or 20% to 50%, the numerical ranges of 10% to 50% or 50% to 80% should also be interpreted as being described herein. Unless otherwise specifically defined in this specification, values ​​outside the numerical range that may occur due to experimental error or rounding of values ​​are also included within the defined numerical ranges.

[0051] Unless otherwise defined herein, “polymer” refers to a molecule of relatively high molecular weight, the structure of which may comprise multiple repetitions of units derived from low molecular weight molecules. In one embodiment, the polymer may be an alternating copolymer, a block copolymer, a random copolymer, a graft copolymer, a gradient copolymer, a branched copolymer, a crosslinked copolymer, or a copolymer comprising all of these (e.g., a polymer comprising more than one monomer). In another embodiment, the polymer may be a homopolymer (e.g., a polymer comprising one monomer).

[0052] Unless otherwise defined herein, “oligomer” may mean a molecule comprising a small number of units or identical repeating units derived from a low molecular weight molecule. An oligomer may comprise fewer monomer units (e.g., fewer than 30 monomer units) than a polymer, and a polymer may comprise more monomer units (e.g., more than 30 monomer units) than an oligomer. In one embodiment, an oligomer may comprise 2 to 20 monomer units.

[0053] The term "alkylene group" in this specification refers to a divalent organic radical derived from an aliphatic hydrocarbon by the removal of two hydrogens, which may include a straight chain or a branched chain form. Examples include, but are not limited to, methylene groups, ethylene groups, propylene groups, isopropylene groups, butylene groups, isobutylene groups, t-butylene groups, pentylene groups, hexylene groups, octylene groups, nonylene groups, etc.

[0054] Unless otherwise specifically defined in this specification, “about” may be considered as a value within 30%, 25%, 20%, 15%, 10%, 5%, 3%, 2%, 1%, or 0.5% of the specified value.

[0055] Hereinafter, the present disclosure will be described in detail (with reference to the attached drawings). However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively.

[0056]

[0057] One embodiment provides a polyesteramide copolymer represented by the following chemical formula 1.

[0058] [Chemical Formula 1]

[0059]

[0060] In the above chemical formula 1, L 1 to L 4 Each is independently a (C1-C7)alkylene group; and m / n is 0.1 or more and 10 or less.

[0061] In one embodiment, the L 1 to L 4 Each may independently be a (C1-C6)alkylene group, a (C2-C6)alkylene group, or a (C3-C5)alkylene group. Additionally, in one embodiment, the L 1 to L 4 Each may independently be methylene, ethylene, propylene, butylene, pentylene, hexylene, or heptylene, but is not necessarily limited thereto.

[0062] In one embodiment, the L 1 to L 4 The fewer the number of carbon chains, the more the polyesteramide copolymer exhibits relative hydrophilicity, and as a result, the surface energy increases, thereby increasing biodegradability, and the composition for forming a coating layer containing the polyesteramide copolymer can have improved adhesion to the substrate layer. Accordingly, a biodegradable film made from the polyesteramide copolymer can have superior biodegradability and adhesion compared to conventional commercial leather.

[0063] In one embodiment, the m / n may be 1 or more and 9 or less. Here, m and n represent the number of moles of ester groups and amide groups of the polyesteramide copolymer, respectively, and as the content of amide groups decreases, the texture of the biodegradable film produced from the copolymer becomes softer. Therefore, when used in leather products, it has a texture similar to existing commercial leather, so the physical properties of the polyesteramide copolymer may vary depending on the ratio of m and n.

[0064] In addition, in one embodiment, the m / n may specifically be 1.5 or more and 9 or less, 2 or more and 6 or less, 2.1 or more and 5 or less, 2.3 or more and 4 or less, or 2.5 or more and 3 or less, but is not necessarily limited thereto.

[0065] In one embodiment, the polyesteramide copolymer may be a polyesteramide copolymer comprising a copolymer represented by the following chemical formula 2.

[0066] [Chemical Formula 2]

[0067]

[0068] In the above chemical formula 2, m / n may be 1 or more and 9 or less. In this case, regarding m and n, the contents regarding m and n described above may be applied in the same way, and duplicate contents below are omitted.

[0069] In one embodiment, the melting point (Tm) of the polyesteramide copolymer may be 60°C or higher and 200°C or lower. Specifically, the melting point may be 70°C or higher and 200°C or lower, 80°C or higher and 200°C or lower, 90°C or higher and 200°C or lower, 100°C or higher and 200°C or lower, 110°C or higher and 190°C or lower, 120°C or higher and 180°C or lower, or 130°C or higher and 170°C or lower, but is not necessarily limited thereto. In this case, if a copolymer with a very low melting point is processed into a biodegradable film, the processing temperature may be too low to be easy to use in leather products; however, the polyesteramide copolymer according to one embodiment has a high melting point and improved thermal stability, so it can be used in biodegradable films used in leather products.

[0070] In one embodiment, the weight-average molecular weight (Mw) of the polyesteramide copolymer may be 20,000 to 200,000 g / mol. Specifically, the weight-average molecular weight may be 30,000 to 180,000 g / mol, 50,000 to 150,000 g / mol, 60,000 to 120,000 g / mol, or 70,000 to 100,000 g / mol, but is not necessarily limited thereto.

[0071] Another embodiment provides a method for preparing a polyesteramide copolymer represented by Formula 1, comprising: (a) a step of obtaining a polyamide salt by reacting a compound represented by Formulas 3 and 4 below; and (b) a step of obtaining a polyesteramide oligomer by reacting the polyamide salt obtained in (a) with a compound represented by Formulas 5 and 6 below.

[0072] [Chemical Formula 1]

[0073]

[0074] [Chemical Formula 3]

[0075]

[0076] [Chemical Formula 4]

[0077]

[0078] [Chemical Formula 5]

[0079]

[0080] [Chemical Formula 6]

[0081]

[0082] In the above Chemical Formula 1 and Chemical Formulas 3 to 6, L 1 to L 4 Each is independently a (C1-C7)alkylene group; and m / n is 0.1 or more and 10 or less.

[0083] In one embodiment, the L 1 to L 4 Each can independently be a (C3-C5)alkylene group.

[0084] In one embodiment, the m / n may be 1 or more and 9 or less.

[0085] At this time, the above L 1 to L 4 And regarding m and n, the L mentioned above 1 to L 4 The contents regarding m and n can be applied identically, and duplicate content below is omitted.

[0086] In one embodiment, the compounds represented by Formulas 3 and 4 are included in an amount of 1 to 50 mol% relative to the total molar amount of compounds represented by Formulas 3 to 6, and the compound represented by Formula 5 may be included in an amount of 50 to 99 mol% relative to the total molar amount of compounds represented by Formulas 3 to 6. Specifically, the compounds represented by Formulas 3 and 4 may be included in an amount of 5 to 45 mol%, 10 to 40 mol%, 15 to 35 mol%, or 20 to 30 mol%, and the compound represented by Formula 5 may be included in an amount of 55 to 95 mol%, 60 to 90 mol%, 65 to 85 mol%, or 70 to 80 mol%, but are not necessarily limited thereto.

[0087] In one embodiment, the compounds represented by Formula 3 and Formula 5 may each be succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, or azelaic acid, but are not necessarily limited thereto.

[0088] In one embodiment, the compound represented by Formula 4 may be methylenediamine, 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, or 1,7-diaminoheptane, but is not necessarily limited thereto.

[0089] In one embodiment, the compound represented by Formula 6 may be methanediol, 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, or 1,7-heptanediol, but is not necessarily limited thereto.

[0090] In one embodiment, the compound represented by Formula 6 may be added in excess for a high degree of polymerization, but the excess compound that does not participate in the reaction is removed in the final step so as not to affect the ester / amide ratio.

[0091] In one embodiment, step (a) may further include a step of raising the temperature under atmospheric pressure. At this time, the temperature range may be 40°C to 90°C, 50°C to 80°C, or 50°C to 70°C, but is not necessarily limited thereto.

[0092] In one embodiment, the polyamide salt obtained in step (a) may be a nylon 46 salt, but is not necessarily limited thereto.

[0093] In one embodiment, step (b) may be performed under a nitrogen atmosphere.

[0094] In one embodiment, step (b) may further include a step of raising the temperature under atmospheric pressure. At this time, the temperature range may be 100 ℃ to 250 ℃, 110 ℃ to 230 ℃, or 120 ℃ to 200 ℃, but is not necessarily limited thereto.

[0095] In one embodiment, step (b) may further include a catalyst. The catalyst may be a titanium-based catalyst, and non-limiting examples include tetraethyl titanate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, and butyl-isopropyl titanate, but are not necessarily limited thereto. Additionally, the catalyst may be added in an amount of 0.0001 to 0.1 moles relative to the total moles of the compound represented by Formula 5, but is not necessarily limited thereto.

[0096] In one embodiment, step (b) may further include the step of adding a branching agent. The branching agent comprises a polyfunctional organic compound containing at least three functional groups selected from hydroxyl groups, carboxyl groups, carboxylic acid anhydrides, and mixtures thereof. For example, it may include glycerol, trimethylolpropane, pentaerythritol, malic acid, tartaric acid, citric acid, trimellitic acid, trimellitic anhydride, trimesic acid, etc., but is not necessarily limited thereto.

[0097] In one embodiment, after step (b), the method may further include step (c) of polycondensing the polyesteramide oligomer to obtain a polyesteramide copolymer.

[0098] In one embodiment, step (c) may include a step of increasing the temperature under vacuum followed by decreasing the pressure. Specifically, the temperature range may be 180°C to 260°C, 190°C to 250°C, or 200°C to 240°C, but is not necessarily limited thereto. Additionally, the pressure range may start at atmospheric pressure (760 Torr) and eventually decrease to a pressure of 1.0 Torr or less, but is not necessarily limited thereto.

[0099] Another embodiment provides a composition for forming a biodegradable coating layer comprising the above-mentioned polyesteramide copolymer.

[0100] In one embodiment, the composition may further include a solvent, and although not particularly limited, may include a non-aqueous or aqueous organic solvent, etc.

[0101] Another embodiment provides a biodegradable film comprising: a substrate layer; and a coating layer formed from a composition for forming a biodegradable coating layer and positioned on at least one surface of the substrate layer.

[0102] In one embodiment, the surface energy of the biodegradable film according to ASTM D7490 may be 40 mN / m or more. Specifically, the surface energy may be 40 mN / m or more and 70 mN / m or less, 43 mN / m or more and 60 mN / m or less, 43 mN / m or more and 55 mN / m or less, or 45 mN / m or more and 50 mN / m, but is not necessarily limited thereto. As the hydrophilic properties of the biodegradable film become more dominant, the surface energy increases and the bonding force with water molecules can become stronger.

[0103] In one embodiment, the measured composting decomposition rate of the biodegradable film at 12 weeks may be 50% or more. Specifically, the measured composting decomposition rate at 12 weeks may be 50% or more and 99% or less, 55% or more and 90% or less, 65% or more and 85% or less, or 70% or more and 85% or less, but is not necessarily limited thereto. In addition, the composting decomposition rate can be measured by monitoring at 2-week intervals for 18 weeks and measuring the weight of the decomposed film relative to the weight of the original film, and the biodegradable film according to one embodiment may decompose 100% during the measurement period.

[0104] In one embodiment, the adhesive strength of the biodegradable film measured according to test method B of ASTM D 3359 may be 3B or higher. Specifically, the adhesive strength of the biodegradable film may be 4B or 5B, but is not necessarily limited thereto.

[0105] In one embodiment, the static friction coefficient (μ) of the biodegradable film and commercial leather measured by a friction and wear tester (Heidon tribogear, 94i-II, Japan) s The difference may be within ±0.1. Specifically, the static friction coefficient (μ) of the biodegradable film and commercial leather s The difference may be within ±0.09, within ±0.07, within 0.05, within ±0.03, within ±0.02, within ±0.01, or within ±0.005, but is not necessarily limited thereto.

[0106] In one embodiment, the substrate layer is polylactic acid (PLA), polypropylene (PP), polyethylene (PE), polyvinyl alcohol (PVA), polyhydroxyalkanoates (PHA), polyethylene terephthalate (PET), poly(caprolactone) (PL), poly(glycolic acid) (PGA), poly(lactidecaprolactone) (PLCL), polybutylene succinate (PBS), polybutylene adipate-co-terephthalate (PBAT), poly(lactic-co-glycolic acid) (PLGA), polyhydroxyalkanoates (PHA), plant-derived It may include one or more biodegradable polymers selected from the group consisting of natural polymers and animal-derived polymers, but is not necessarily limited thereto. Specifically, the substrate layer may be a mushroom material.

[0107] In one embodiment, the coating method known as the above may be used without limitation, and may be carried out using methods such as doctor-blade coating, bar coating, comma coating, gravure coating, microgravure coating, dip coating, spray coating, slot die coating, casting, multilayer simultaneous die coating, and imprinting.

[0108] Another embodiment provides a biodegradable leather product comprising the biodegradable film. Specifically, the biodegradable leather product may be clothing, shoes, bags, accessories, luggage, household coverings, and car seats, but is not necessarily limited thereto.

[0109]

[0110] In the following, embodiments are further described with reference to specific experimental examples. The embodiments and comparative examples included in the experimental examples are merely illustrative of one embodiment and do not limit the appended claims. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope and spirit of the present disclosure, and that such variations and modifications fall within the scope of the appended claims.

[0111]

[0112] <Example 1> Preparation of Polyesteramide Copolymer (E9A1)

[0113] Step 1: Preparation of Polyamide Salts

[0114] To mix adipic acid (AA, manufactured by Sigma-Aldrich, USA) and 1,4-diaminobutane (DAB, manufactured by Sigma-Aldrich, USA) in a 1:1 molar ratio, adipic acid (14.61 g, 0.1 mol) and 1,4-diaminobutane (8.82 g, 0.1 mol) were added to a 500 ml flask and dissolved in 23.43 g of distilled water. After stirring for 30 minutes at 50 ℃ under atmospheric pressure, the temperature was raised to 70 ℃ over 1 hour to obtain a yellow polyamide salt.

[0115] Step 2: Preparation of Polyesteramide Oligomer

[0116] After placing the polyamide salt obtained in Step 1 into a 500 mL round-bottom flask, adipic acid (131.49 g, 0.9 mol) and 1,4-butanediol (1,4-butanediol, BDO, manufactured by Sigma-Aldrich, USA) (121.66 g, 1.35 mol) were added and mixed to synthesize an ester / amide (molar ratio) of 9:1. After stirring at a stirring speed of 100 rpm at 120 °C under a nitrogen atmosphere, titanium(IV) butoxide (manufactured by Sigma-Aldrich, USA) (0.2 g, 0.0006 mol), which is a catalyst, was added, and the temperature was raised to 200 °C at a rate of 1 °C / min. After maintaining at 200 °C for about 1 hour, a polyesteramide oligomer was obtained.

[0117] Step 3: Preparation of Polyesteramide Copolymer

[0118] Polyesteramide copolymers were prepared by polycondensation of the polyesteramide oligomers prepared in the above Step 2 under vacuum, and the specific polymerization method is as follows. Titanium(IV) butoxide (manufactured by Sigma-Aldrich, USA) (0.2 g, 0.0006 mol) was added as a catalyst, and while the temperature was increased from 200 °C to 240 °C at a rate of 1 °C / min, the pressure was gradually reduced from atmospheric pressure (760 Torr) to finally 500 mTorr, and the reaction was carried out by stirring the reactants at a speed of 200 rpm. As the polymerization reaction proceeded, the viscosity of the reactants in the reactor gradually increased and could be visually observed wrapping around the stirrer, and when the torque on the overhead stirrer increased to 200 N·cm, the stirring speed was gradually reduced. Finally, when the torque at 50 rpm reached 200 N·cm, the reaction was terminated, the residue was removed with distilled water, and the polyesteramide copolymer (E9A1) was obtained by drying under vacuum at 30 ℃ for 24 hours.

[0119] 1 H-NMR (600 MHz, HFIP-d2): 2.62 (2H, t), 2.75 (2H, s), 3.62 (2H, s), 4.5 (2H, s).

[0120]

[0121] <Example 2> Preparation of Polyesteramide Copolymer (E8A2)

[0122] A polyesteramide copolymer (E8A2) was obtained by preparing it in the same manner as in Example 1, except that in Step 1 of Example 1, 29.22 g of adipic acid and 17.64 g of 1,4-diaminobutane were dissolved in 46.86 g of distilled water, and in Step 2, 116.88 g of adipic acid and 108.14 g of 1,4-butanediol were added to synthesize an ester / amide molar ratio of 8:2.

[0123] 1 H-NMR (600 MHz, HFIP-d2): 2.62 (2H, t), 2.75 (2H, s), 3.62 (2H, s), 4.5 (2H, s).

[0124]

[0125] <Example 3> Preparation of Polyesteramide Copolymer (E7A3)

[0126] A polyesteramide copolymer (E7A3) was obtained by preparing it in the same manner as in Example 1, except that in Step 1 of Example 1, 43.83 g of adipic acid and 26.46 g of 1,4-diaminobutane were dissolved in 70.29 g of distilled water, and in Step 2, 102.27 g of adipic acid and 121.66 g of 1,4-butanediol were added to synthesize an ester / amide molar ratio of 7:3.

[0127] 1 H-NMR (600 MHz, HFIP-d2): 2.62 (2H, t), 2.75 (2H, s), 3.62 (2H, s), 4.5 (2H, s).

[0128]

[0129] <Example 4> Preparation of Polyesteramide Copolymer (E6A4)

[0130] A polyesteramide copolymer (E6A4) was obtained by preparing it in the same manner as in Example 1, except that in Step 1 of Example 1, 58.44 g of adipic acid and 35.28 g of 1,4-diaminobutane were dissolved in 93.72 g of distilled water, and in Step 2, 87.66 g of adipic acid and 81.11 g of 1,4-butanediol were added to synthesize an ester / amide molar ratio of 6:4.

[0131] 1 H-NMR (600 MHz, HFIP-d2): 2.62 (2H, t), 2.75 (2H, s), 3.62 (2H, s), 4.5 (2H, s).

[0132]

[0133] The intrinsic viscosity (η), melting point (Tm), crystallization temperature (Tc), glass transition temperature (Tg), tensile strength, elongation, and toughness of the polyesteramide copolymers according to Examples 1 to 4 were analyzed and are shown in Table 1 below. The specific analysis method is as follows. First, the intrinsic viscosity was analyzed at 30 °C using an Uberdo viscometer according to the ASTM D4603 analysis method, and HFIP (1,1,1,3,3,3-hexafluoro-2-propanol) was used as the analysis solvent. The melting point, crystallization temperature, and glass transition temperature were measured using differential scanning calorimetry (DSC). The temperature was raised from -70 °C to 300 °C at a rate of 10 °C / min, then slowly cooled at the same rate, and then raised again. Tensile strength and toughness were expressed in MPa using a Universal Testing Machine (UTM), and elongation was indicated by converting these values ​​to a percentage.

[0134] Example 1 Example 2 Example 3 Example 4 Ester:Amide Molar Ratio 9:18:27:36:4 Intrinsic Viscosity (η, dl / g) 1.66 1.49 1.59 1.44 Melting Point (Tm, °C) 5 114 7 175 199 Crystallization Temperature (Tc, °C) 0.68 98 130 160 Glass Transition Temperature (Tg, °C) -52 -48 -42 -33 Tensile Strength (MPa) 42.8 48.75 5.56 9.3 Toughness (MPa) 30 433 337 0 417 Elongation (%) 15 24 139 71 225 10 66

[0135] <Comparative Example 1> Preparation of Polyesteramide Copolymer

[0136] A polyesteramide copolymer was obtained by preparing it in the same manner as in Example 1, except that sebacic acid was used instead of adipic acid in Example 1.

[0137]

[0138] <Comparative Example 2> Preparation of Polyesteramide Copolymer

[0139] A polyesteramide copolymer was obtained by preparing it in the same manner as in Example 2, except that sebacic acid was used instead of adipic acid in Example 2.

[0140]

[0141] <Comparative Example 3> Preparation of Polyesteramide Copolymer

[0142] A polyesteramide copolymer was obtained by preparing it in the same manner as in Example 3, except that sebacic acid was used instead of adipic acid in Example 3.

[0143]

[0144] <Comparative Example 4> Preparation of Polyesteramide Copolymer

[0145] A polyesteramide copolymer was obtained by preparing it in the same manner as in Example 4, except that sebacic acid was used instead of adipic acid in Example 4.

[0146]

[0147] <Comparative Example 5> Preparation of Polybutylene Adipate (PBA)

[0148] Adipic acid (146.14 g, 1 mol) and 1,4-butanediol (135.18 g, 1.5 mol) were added to a 500 mL round-bottom flask and mixed. After stirring at a stirring speed of 100 rpm at 120 °C under a nitrogen atmosphere, titanium(IV) butoxide (0.2 g, 0.0006 mol), a catalyst, was added and the temperature was raised to 200 °C at a rate of 1 °C / min. After maintaining the temperature at 200 °C for about 1 hour, titanium(IV) butoxide (0.2 g, 0.0006 mol), a catalyst, was added again and the temperature was raised to 240 °C at a rate of 1 °C / min while the pressure was reduced to 500 mTorr. The reaction mixture was maintained at 240°C for 4 hours, then the residue was removed with distilled water and dried under vacuum at 30°C for 24 hours to obtain polybutylene adipate (PBA).

[0149]

[0150] <Comparative Example 6> Preparation of Nylon Salt (Nylon 46)

[0151] Nylon 46 was prepared from the commercial product KS 411 of Stanyl.

[0152] <Comparative Example 7> Preparation of Thermoplastic Polyurethane (TPU)

[0153] TPU (WHT-1190, WANTHANE) was prepared.

[0154] <Comparative Example 8> Preparation of Polybutylene Sebacate (PBSe)

[0155] Sebacic acid (202.25 g, 1 mol) and 1,4-butanediol (135.18 g, 1.5 mol) were added to a 500 mL round-bottom flask and mixed. After stirring at a stirring speed of 100 rpm at 120 °C under a nitrogen atmosphere, titanium(IV) butoxide (0.2 g, 0.0006 mol), a catalyst, was added and the temperature was raised to 200 °C at a rate of 1 °C / min. After maintaining the temperature at 200 °C for about 1 hour, titanium(IV) butoxide (0.2 g, 0.0006 mol), a catalyst, was added again and the temperature was raised to 240 °C at a rate of 1 °C / min while the pressure was reduced to 500 mTorr. The reaction mixture was maintained at 240°C for 4 hours, then the residue was removed with distilled water and dried under vacuum at 30°C for 24 hours to obtain polybutylene sebacate (PBSe).

[0156]

[0157] The intrinsic viscosity (η), melting point (Tm), crystallization temperature (Tc), glass transition temperature (Tg), tensile strength, elongation, and toughness of the copolymers according to Comparative Examples 1 to 8 were analyzed and are shown in Table 2 below, and were measured using the same method as the physical property measurement method of Examples 1 to 4 above.

[0158] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Ester:amide molar ratio 9:18:27:36:4 10:00:10 -10:0 Intrinsic viscosity (dl / g) 1.3 1.29 1.4 2.37 1.24 1.5 2.146 1.32 Melting point (Tm, °C) 39 10 31 7 31 7 7 5 4 2 7 9 39 6 4 Crystallization temperature (Tc, °C) 2 2 10 9 14 11 5 5 2 9 23 3 2 2 4 7 Glass transition temperature (Tg, ℃)-59-55-50-47-5752-9-59 Tensile Strength (MPa) 42.744.952.752.031.68260.334.2 Toughness (MPa) 418613521100816792241917961 Elongation (%) 819110213531487140139824866

[0159]

[0160] <Experimental Example 1> Evaluation of Adhesion Strength of Biodegradable Film

[0161] To evaluate whether the copolymers of Examples 1 to 4 are suitable as coating materials, the copolymers were dip-coated onto a mushroom substrate (Mycoworld) to produce a film, and then the adhesion strength was measured.

[0162] The specific experimental method is as follows. First, to verify the adhesion in organic solvents, the copolymers of Examples 1 to 4 were dissolved in HFIP solvent to prepare a 5 wt% polymer solution, which was then placed in a 100 mL vial. A mushroom fabric measuring 5 cm x 5 cm was then immersed in the polymer solution and completely dried. Subsequently, the dip-coated film was cut into 2 mm intervals, tape was applied to ensure complete adhesion, and the peel strength was verified by rapidly tearing it off. The peel strength of the film was measured according to test method B of ASTM D 3359, and the evaluation methods were classified into 5B, 4B, 3B, 2B, 1B, and 0B.

[0163] 5B: The state with the best adhesive strength, with absolutely no peeling at the cross-cut points.

[0164] 4B: Condition where less than 5% delaminates

[0165] 3B: Condition of delamination between 5% and less than 15%

[0166] 2B: Condition where 15% or more but less than 35% delamination occurs

[0167] 1B: Condition where 35% or more but less than 65% delamination occurs

[0168] 0B: A state where almost all of it is peeled off to the point of being immeasurable.

[0169] After confirming the adhesion strength in organic solvents, the film was placed in a solvent with a water-to-ethanol ratio of 3:7 to confirm the adhesion strength in a water / ethanol solution and stirred at 60°C. After confirming complete dissolution, the peel strength of the film was measured using the same method as the peel strength measurement method in organic solvents, and the summarized results are shown in Table 3.

[0170] HFIP Water / Ethanol Example 14B4B Example 24B4B Example 35B5B Example 45B5B

[0171] When evaluating the peel strength of commercial leather (natural cowhide and synthetic PU leather (LEJARIA)) using the same measurement method as above, the peel strength of natural cowhide was 4B, and the peel strength of synthetic PU leather was 5B. Comparing this with the results in Table 3 above, it can be seen that when Examples 1 to 4 are used as coating materials, they have superior adhesion compared to conventional natural leather and similar adhesion to synthetic leather.

[0172]

[0173] <Experimental Example 2> Evaluation of Frictional Force of Biodegradable Film

[0174] To evaluate whether the coating materials used in Examples 1 to 4 have a tactile feel similar to commercial products (natural cowhide and synthetic PU leather), the friction force with the skin was measured and is shown in Tables 4 and 5. The coefficient of friction was measured using a friction and wear tester (Heidon tribogear, 94i-II, Japan). The static friction coefficient of the film obtained by dip-coating the Examples and Comparative Examples onto a mushroom fabric using the same method as in Experimental Example 1 was measured and is shown in Table 4 below, and the friction coefficient between the dip-coated film and the skin was measured and is shown in Table 5 below.

[0175] Coefficient of static friction (μ s Natural cowhide 0.454 Synthetic PU leather 0.398 Deep coating film Example 20.452 Example 30.425 Example 40.175 Comparative Example 70.475

[0176] coefficient of friction (μ s Natural cowhide 0.939 Example 20.972 Example 30.859 Example 41.181

[0177] When comparing the friction coefficients through Tables 4 and 5 above, it can be seen that the friction coefficients of the dip-coated films of Examples 2 and 3 are similar to the friction coefficient values ​​of natural leather, indicating that the films coated with the copolymers of the examples have a tactile feel similar to natural leather. In particular, the static friction coefficient of the fabric dip-coated with the copolymer of Example 2 is 0.452, which is the closest value to the static friction coefficient of natural leather; this is because the tactile feel of the film becomes softer as the amide content decreases. Therefore, it can be seen that when the film coated with the polyesteramide copolymer of Example 2 is used in a leather product, it has a tactile feel most similar to natural leather.

[0178]

[0179] <Experimental Example 3> Evaluation of Biodegradability of Biodegradable Film

[0180] To evaluate the biodegradability of Examples 1 to 4, the contact angle and surface energy of the biodegradable films and water according to the examples and comparative examples were measured. Specifically, the contact angle was measured using a Drop Shape Analyzer (KRUSS, DSA25, Germany), and the surface energy was measured by the calculation method according to ASTM D7490, and the results are summarized in Table 6 below.

[0181] Contact angle with water (°) Surface energy (mN / m) Example 16847 Example 26448 Example 36149 Example 45850 Comparative Example 17240 Comparative Example 27041 Comparative Example 36842 Comparative Example 46643

[0182] Table 6 shows that the biodegradable films prepared in Examples 1 to 4 have a smaller contact angle with water and a larger surface energy compared to the film prepared in the Comparative Example. This is because sebacic acid included in the polymer of the Comparative Example has a longer number of carbon chains than adipic acid included in the polymer of the Example, making it relatively hydrophobic; consequently, the hydrogen bonding force and surface energy are lowered, which reduces the bonding force with water molecules.

[0183] In addition, a polymer film prepared by hot-pressing the above polymer to a thickness of 0.5 mm was buried in composting soil (humidity 50%, temperature 60 ℃) with a carbon / nitrogen ratio of 25.30, and biodegradability was measured every 2 weeks for a total of 18 weeks. The degradation rates (%) of the polyesteramide copolymers according to Examples 1 to 4 are shown in Table 7 below. As a result, Example 1 was completely degraded in 14 weeks, Example 2 in 18 weeks, and Examples 3 and 4 in 16 weeks. In particular, more than 50% of the Examples were degraded starting from the 12th week, whereas Comparative Examples 1 to 4 were not completely degraded during the measurement period. Therefore, it can be seen that the polyesteramide copolymer of the Examples, which is a material with short carbon chains and high hydrophilicity, degraded rapidly and has excellent biodegradability.

[0184] 2 weeks 4 weeks 6 weeks 8 weeks 10 weeks 12 weeks 14 weeks 16 weeks 18 weeks Example 1 1.5 3 2 2.3 3 5.78 6 7.89 8 0.31 9 0.01 98 6 4 100 100 Example 20.4 4 1.2 1 1.9 2 7.1 3 2 1.05 5 0.71 5 9.69 8 4.98 99 39 Example 30.00 2.3 4 2.67 1 2.8 14 3.06 8 2.37 9 5.38 99 6 3 100 Example 40.8 0.8 1.01 2 5.96 5 4.05 7 4.77 9 0.61 96 6 45 100

[0185] The above description is merely an example applying the principles of the present disclosure, and other configurations may be further included without departing from the scope of the present disclosure. Although one embodiment has been described in detail through examples and experimental examples, the scope of one embodiment is not limited to specific embodiments and should be interpreted according to the appended claims.

Claims

1. Polyesteramide copolymer represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, L 1 to L 4 Each is independently a (C1-C7)alkylene group; and m / n is 0.1 or greater and 10 or less.

2. In Paragraph 1, The above L 1 to L 4 Polyesteramide copolymers, each independently having a (C3-C5)alkylene group.

3. In Paragraph 1, Polyesteramide copolymer, wherein m / n is 1 or more and 9 or less.

4. In Paragraph 1, The above-mentioned polyesteramide copolymer comprises a copolymer represented by the following chemical formula 2, a polyesteramide copolymer: [Chemical Formula 2] In the above chemical formula 2, m / n is 1 or more and 9 or less.

5. In Paragraph 1, Polyesteramide copolymer having a melting point (Tm) of 60°C or higher and 200°C or lower.

6. (a) a step of obtaining a polyamide salt by reacting compounds represented by the following chemical formulas 3 and 4; and (b) a step of reacting the polyamide salt obtained in (a) with a compound represented by the following chemical formulas 5 and 6 to obtain a polyesteramide oligomer; comprising a method for preparing a polyesteramide copolymer represented by chemical formula 1: [Chemical Formula 1] [Chemical Formula 3] [Chemical Formula 4] [Chemical Formula 5] [Chemical Formula 6] In the above Chemical Formula 1 and Chemical Formulas 3 to 6, L 1 to L 4 Each is independently a (C1-C7)alkylene group; and m / n is 0.1 or greater and 10 or less.

7. In Paragraph 6, The above L 1 to L 4 A method for preparing a polyesteramide copolymer, each having an independently (C3-C5)alkylene group.

8. In Paragraph 6, A method for manufacturing a polyesteramide copolymer, wherein the m / n is 1 or more and 9 or less.

9. In Paragraph 6, A method for preparing a polyesteramide copolymer, wherein the compounds represented by Chemical Formulas 3 and 4 are included in an amount of 1 to 50 mol% relative to the total molar amount of compounds represented by Chemical Formulas 3 to 6, and the compound represented by Chemical Formula 5 is included in an amount of 50 to 99 mol% relative to the total molar amount of compounds represented by Chemical Formulas 3 to 6.

10. In Paragraph 6, A method for producing a polyesteramide copolymer, further comprising the step of (c) polycondensing the polyesteramide oligomer to obtain a polyesteramide copolymer after step (b) above.

11. A composition for forming a biodegradable coating layer comprising a polyesteramide copolymer according to any one of claims 1 to 5.

12. Substrate layer; and A biodegradable film comprising: a coating layer formed from a composition for forming a biodegradable coating layer according to claim 11, located on at least one surface of the above-mentioned substrate layer.

13. In Paragraph 12, Biodegradable film having a surface energy of 40 mN / m or more according to ASTM D7490.

14. In Paragraph 12, Biodegradable film with a measured 12-week composting decomposition rate of 50% or more.

15. In Paragraph 12, A biodegradable film having an adhesion strength of 3B or higher as measured by test method B of ASTM D 3359.

16. In Paragraph 12, The static friction coefficient (μ) of the above biodegradable film and commercial leather measured by a friction and wear tester (Heidon tribogear, 94i-II, Japan) s Biodegradable film with a difference of within ±0.

1.

17. In Paragraph 12, The above substrate layer is polylactic acid (PLA), polypropylene (PP), polyethylene (PE), polyvinyl alcohol (PVA), polyhydroxyalkanoates (PHA), polyethylene terephthalate (PET), poly(caprolactone) (PL), poly(glycolic acid) (PGA), poly(lactidecaprolactone) (PLCL), polybutylene succinate (PBS), polybutylene adipate-co-terephthalate (PBAT), poly(lactic-co-glycolic acid) (PLGA), polyhydroxyalkanoates (PHA), and plant-derived natural polymers. A biodegradable film comprising one or more biodegradable polymers selected from the group consisting of animal-derived polymers.

18. Biodegradable leather products comprising a biodegradable film according to paragraph 12.

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