Polyalkylene carbonate resin composition and method for preparing same

Abstract

The present invention relates to a polyalkylene carbonate resin composition having excellent thermal stability and a method for preparing the same. The polyalkylene carbonate resin composition includes a polyalkylene carbonate, a chain extender, and at least one additive selected from the group consisting of an organic acid and an acid anhydride.

Description

Technical Field

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002] This application claims the benefit of Korean Patent Application No. 10-2023-0060479 filed in the Korean Intellectual Property Office on May 10, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0004] The invention relates to a polyalkylene carbonate resin composition with excellent thermal stability and a preparation method thereof. Background Art

[0005] Since the Industrial Revolution, humans have built modern society by consuming large amounts of fossil fuels, but environmental damage such as deforestation is increasing the concentration of carbon dioxide in the air. Since the increase in carbon dioxide concentration is one of the causes of increasing the greenhouse effect, it is important to reduce the concentration of carbon dioxide in the air, which contributes greatly to global warming, and various studies on carbon dioxide emission systems, fixation, etc. are being conducted.

[0006] Recently, polyalkylene carbonate resins obtained by polymerizing carbon dioxide with epoxides have received great attention as a biodegradable resin. In particular, the process of preparing polyalkylene carbonate resins using carbon dioxide can fix the amount of carbon dioxide in the air to reduce the global warming problem, and active research has also been conducted from the perspective of using carbon dioxide as a carbon source.

[0007] However, since the polyalkylene carbonate resin has low thermal stability and is thermally decomposed at a temperature equal to or higher than 180° C., there are significant limitations in industrial applications.

[0008] In addition, in order to prepare the polyalkylene carbonate resin, not only carbon dioxide and epoxide but also a catalyst is required, and thus, as a typical heterogeneous catalyst, a zinc dicarboxylate catalyst such as a zinc glutarate catalyst combined with a dicarboxylic acid; and a double metal cyanide catalyst composed of a complex of Co, Zn, Al, etc. are used.

[0009] When such a catalyst remains in the resin, polymer chain decomposition is accelerated in a heat treatment process of the resin, so that the thermal stability of the polyalkylene carbonate resin is reduced. Therefore, it is necessary to develop various purification technologies for removing the catalyst after the polymerization is completed.

[0010] For example, CN 103842406 B discloses a method for preparing polyalkylene carbonate, wherein polyalkylene carbonate is prepared in an organic solvent in the presence of a catalyst, the organic solvent is removed to form polyalkylene carbonate particles, and then an acidic aqueous solution containing 0.01 wt % to 5 wt % of an acid without an organic solvent is added to the polyalkylene carbonate particles, followed by solid-liquid mixing, heat treatment and drying. However, the problem is that, in the method for solid-liquid mixing by adding an acidic aqueous solution, the polyalkylene carbonate is present in the acidic aqueous solution in the form of particles (solid), and therefore, the catalyst remaining in the polyalkylene carbonate has a low deactivation efficiency and requires a large amount of acid.

[0011] [Prior art]

[0012] [Patent Document]

[0013] (Patent Document 1) CN 103842406 B (2016.11.02) Summary of the invention

[0014] Technical issues

[0015] One aspect of the present invention provides a polyalkylene carbonate resin composition having excellent thermal stability.

[0016] One aspect of the present invention also provides a method for preparing the polyalkylene carbonate resin composition.

[0017] Technical Solution

[0018] According to one aspect of the present invention, a polyalkylene carbonate resin composition and a preparation method thereof are provided.

[0019] (1) The present invention provides a polyalkylene carbonate resin composition, comprising: polyalkylene carbonate, a chain extender and at least one additive selected from an organic acid and an acid anhydride.

[0020] (2) In the above (1), the content of the additive is 0.001 parts by weight to 5.000 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

[0021] (3) In the above (1) or (2), the organic acid is at least one selected from citric acid, tartaric acid, ascorbic acid and maleic acid.

[0022] (4) In any one of the above (1) to (3), the acid anhydride is a dicarboxylic acid anhydride having 4 to 8 carbon atoms.

[0023] (5) In any one of the above (1) to (4), the content of the chain extender is 0.01 parts by weight to 3.00 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

[0024] (6) In any one of the above (1) to (5), the chain extender is at least any one selected from 2,2′-(1,3-phenylene)bis-2-oxazoline, 2,2′-bis(2-oxazoline) and a compound represented by the following Formula 1.

[0025] [Formula 1]

[0026]

[0027] In the above formula 1,

[0028] R1 to R5 are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,

[0029] R6 is an alkyl group having 1 to 10 carbon atoms,

[0030] p, q and r are each independently a real number of 1 to 20.

[0031] (7) In any one of the above (1) to (6), the additive and the chain extender are contained in a weight ratio of 1:0.1 to 20.0.

[0032] (8) In any one of the above (1) to (7), the polyalkylene carbonate resin composition further contains an antioxidant.

[0033] (9) In any one of the above (1) to (8), an antioxidant is further contained in an amount of 0.01 parts by weight to 3.00 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

[0034] (10) In any one of the above (8) or (9), the antioxidant is selected from tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, triethylene glycol-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine, octadecyl 3-(3,5-di-tert-butyl-4-hydroxy-5-methylphenyl)propionate At least any one of 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 2,4-di-tert-pentyl-6-(1-(3,5-di-tert-pentyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, α-tocopherol and 2,6-di-tert-butyl-p-cresol.

[0035] (11) In any of the above (1) to (10), the molecular weight change rate defined by the following equation 1 is equal to or less than 35%.

[0036] [Equation 1]

[0037] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 )×100

[0038] In equation 1 above,

[0039] M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, M W2 is the weight average molecular weight of the polyalkylene carbonate resin composition after heat treatment at 180° C. for 20 minutes as measured by gel chromatography.

[0040] (12) In any one of the above (1) to (11), the polyalkylene carbonate includes a repeating unit represented by the following Formula 2 and a repeating unit represented by the following Formula 3.

[0041] [Formula 2]

[0042]

[0043] [Formula 3]

[0044]

[0045] In equation 2 and equation 3,

[0046] R1 to R8 are each independently hydrogen, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms,

[0047] * refers to the connection site between repeating units,

[0048] x and y are mole fractions, x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

[0049] (13) In any one of the above (1) to (12), the polyalkylene carbonate is at least any one selected from polyethylene carbonate, polypropylene carbonate, polypentylene carbonate, polyhexylene carbonate, polyoctylene carbonate and polycyclohexylene carbonate.

[0050] (14) The present invention provides a method for preparing a polyalkylene carbonate resin composition, comprising: step (S1), preparing a polymer containing polyalkylene carbonate by polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst; step (S2), adding a chain extender and at least one additive selected from an organic acid and an acid anhydride to the polymer, and stirring; and step (S3), removing the solvent.

[0051] (15) In the above (14), in step (S2), the additive is added in an amount of 0.001 parts by weight to 5.000 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

[0052] (16) In the above (14) or (15), in step (S2), the additive and the chain extender are contained in a weight ratio of 1:0.1 to 20.0.

[0053] (17) In any one of the above (14) to (16), in step (S2), before adding the chain extender and the additive to the polymer, a solvent is additionally added to the polymer so that the polyalkylene carbonate solid content in the polymer is 10 wt % to 40 wt %.

[0054] (18) In any one of the above (14) to (17), in step (S2), an antioxidant is further added to the polymer.

[0055] (19) In any one of the above (14) to (18), the catalyst comprises a double metal cyanide compound and a complexing agent.

[0056] (20) In the above (19), the complexing agent is selected from cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-propylcyclopentanol, 2-propylcyclopentanol, 3-propylcyclopentanol, 1-butylcyclopentanol, 2-butylcyclopentanol, 3-butylcyclopentanol, Cyclopentanol, 1-isopropylcyclopentanol, 2-isopropylcyclopentanol, 3-isopropylcyclopentanol, 1-(propan-2-yl)cyclopentanol, 2,2-dimethylcyclopentanol, 2,3-dimethylcyclopentanol, 3,3-dimethylcyclopentanol, 1,2-dimethylcyclopentanol, 1,3-dimethylcyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol, 1-propylcyclohexanol, 1-butylcyclohexanol, 2 -methyl-1-cyclohexanol, 2-ethyl-1-cyclohexanol, 3-ethyl-1-cyclohexanol, 4-ethyl-1-cyclohexanol, 2-propyl-1-cyclohexanol, 3-propyl-1-cyclohexanol, 4-propyl-1-cyclohexanol, 2-butyl-1-cyclohexanol, 3-butyl-1-cyclohexanol, 4-butyl-1-cyclohexanol, 2-isopropyl-1-cyclohexanol, 3-isopropyl-1-cyclohexanol At least any one of cyclohexanol, 4-isopropyl-1-cyclohexanol, 2-tert-butyl-1-cyclohexanol, 3-tert-butyl-1-cyclohexanol, 4-tert-butyl-1-cyclohexanol, 2,3-dimethyl-1-cyclohexanol, 2,4-dimethyl-1-cyclohexanol, 3,4-dimethyl-1-cyclohexanol, 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol and 4-methylcycloheptanol.

[0057] Beneficial Effects

[0058] Since the polyalkylene carbonate resin composition according to the present invention contains a chain extender and an organic acid and / or anhydride, it has an effect of improving thermal stability by increasing the thermal decomposition temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The following drawings attached to the specification illustrate preferred embodiments of the present invention by way of example, and together with the detailed description of the present invention given below, are used to further understand the technical concept of the present invention. Therefore, the present invention should not be understood solely based on the matters in these drawings:

[0060] Figure 1 This is a graph showing the results of mass change analysis of the polyalkylene carbonate resin compositions prepared in Examples and Comparative Examples using a thermogravimetric analyzer. DETAILED DESCRIPTION

[0061] Hereinafter, the present invention will be described in more detail to help understanding of the present invention.

[0062] It will be understood that the words or terms used in this specification and claims should not be understood as the meanings defined in commonly used dictionaries, and it will also be understood that, based on the principle that the inventor can appropriately define the meanings of words or terms to best illustrate the invention, the words or terms should be understood as having meanings consistent with their meanings in the context of the relevant technology and the technical concept of the present invention.

[0063] Definition of terms

[0064] In the present specification, the term "alkyl group" may refer to a monovalent saturated aliphatic hydrocarbon.

[0065] In the present specification, the term "aryl group" may refer to a cyclic aromatic hydrocarbon, and may refer to both a monocyclic aromatic hydrocarbon in which one ring is formed or a polycyclic aromatic hydrocarbon in which two or more rings are bonded to each other.

[0066] In the present specification, the term "alkenyl group" may refer to a monovalent unsaturated aliphatic hydrocarbon including one or at least two double bonds.

[0067] In the present specification, the term "cycloalkyl group" may refer to both a cyclic saturated hydrocarbon or a cyclic unsaturated hydrocarbon including one or at least two unsaturated bonds.

[0068] Measurement method

[0069] In this specification, the molecular weight characteristics are analyzed by gel permeation chromatography (GPC) using polystyrene as a standard material, and specifically measured using GPC (Waters 1515 isocratic HPLC pump, Waters 2414 refractive index detector, Waters Inc.) under the following conditions.

[0070] Column: Two Agilent PLgel MIXED-B (7.5 mm × 300, 10 μm)

[0071] Solvent: Chloroform

[0072] Flow rate: 0.Tml / min

[0073] Column temperature: 40°C

[0074] Sample: 4.0 mg / 1.0 ml of chloroform

[0075] Injection volume: 20 μl

[0076] Standard material: Polystyrene

[0077] In the present specification, the mass change analysis is measured using a thermogravimetric analyzer (TGA), and specifically, is measured using a thermogravimetric analyzer (TGA2, Mettler Toledo) under the following conditions.

[0078] 1) Step 1: Increase the temperature from 30°C to 150°C (10°C / min)

[0079] 2) Step 2: Keep at 150°C for 5 minutes

[0080] 3) Step 3: Reduce the temperature from 150°C to 30°C (10°C / min)

[0081] 4) Step 4: Keep at 30°C for 5 minutes

[0082] 5) Step 5: Increase the temperature from 30°C to 400°C (10°C / min)

[0083] Polyalkylene carbonate resin composition

[0084] The present invention provides a polyalkylene carbonate resin composition having improved thermal stability by suppressing thermal decomposition.

[0085] A polyalkylene carbonate resin composition according to one embodiment of the present invention is characterized by comprising: polyalkylene carbonate, a chain extender, and at least one additive selected from an organic acid and an acid anhydride.

[0086] Polyalkylene carbonate resin is prepared by using carbon dioxide as a source and has received great attention as a biodegradable resin, but due to the low thermal stability of the polyalkylene carbonate resin, it is thermally decomposed at a temperature of at least 180° C. and has significant limitations in industrial applications. In addition, in order to prepare the polyalkylene carbonate resin, not only carbon dioxide and epoxide but also a catalyst is required, and when such a catalyst remains in the resin, the polymer chain decomposition is accelerated in the heat treatment process of the resin, resulting in a decrease in the thermal stability of the polyalkylene carbonate resin, and therefore, it is necessary to develop various purification technologies for removing the catalyst after the polymerization is completed.

[0087] However, in the polyalkylene carbonate resin composition according to one embodiment of the present invention, after the polymerization of the polyalkylene carbonate, a chain extender and at least one additive of an organic acid and an acid anhydride may be directly added to the polymer to deactivate the remaining catalyst without any additional process such as extraction or precipitation, and thermal decomposition is suppressed, thereby being able to have excellent thermal stability.

[0088] Hereinafter, the polyalkylene carbonate resin composition will be described more specifically by dividing it into components contained therein.

[0089] Polyalkylene carbonate

[0090] According to the present invention, the polyalkylene carbonate may include a repeating unit represented by the following Formula 2 and a repeating unit represented by the following Formula 3 as a polymer prepared by polymerizing an alkylene oxide compound with carbon dioxide.

[0091] [Formula 2]

[0092]

[0093] [Formula 3]

[0094]

[0095] In the above formula 2 and formula 3,

[0096] R1 to R8 are each independently hydrogen, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, * indicates a connection site between repeating units, x and y are molar fractions, x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

[0097] In addition, x may be 0.80 to 1.00, y may be 0.00 to 0.20, and preferably, x may be 0.90 to 1.00, y may be 0.00 to 0.10. When the range is met, the fixation rate of carbon dioxide is high, so as to effectively reduce greenhouse gases, and is conducive to biodegradation properties. In addition, when the polyalkylene carbonate according to the present invention is prepared as a film, the film exhibits low oxygen permeability, thereby exhibiting excellent barrier properties.

[0098] The polyalkylene carbonate may be at least any one selected from polyethylene carbonate, polypropylene carbonate, polypentylene carbonate, polyhexylene carbonate, polyoctylene carbonate and polycyclohexylene carbonate. In addition, in the above formula 1, R1 to R8 are each independently hydrogen, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms, and an appropriate functional group may be selected in consideration of the final physical properties of the resin to be obtained.

[0099] In addition, the repeating unit represented by the above Formula 2 may be represented by Formula 4 below.

[0100] [Formula 4]

[0101]

[0102] In the above Formula 4, R1 to R4 are each independently hydrogen or a linear alkyl group having a carbon number of 1 to 10, and x and * are the same as defined in the above Formula 1.

[0103] More specifically, the repeating unit represented by Formula 2 above may be represented by Formula 5 or Formula 6 below.

[0104] [Formula 5]

[0105]

[0106] [Formula 6]

[0107]

[0108] In the above Formula 5 and Formula 6, x and * are the same as defined in the above Formula 2.

[0109] In addition, the repeating unit represented by the above Formula 3 may be represented by the following Formula 7.

[0110] [Formula 7]

[0111]

[0112] In the above Formula 7, R5 to R8 are each independently hydrogen or a linear alkyl group having a carbon number of 1 to 10, and y and * are the same as defined in the above Formula 3.

[0113] More specifically, the repeating unit represented by Formula 3 above may be represented by Formula 8 or Formula 9 below.

[0114] [Formula 8]

[0115]

[0116] [Formula 9]

[0117]

[0118] In the above Formula 8 and Formula 9, y and * are the same as defined in the above Formula 3.

[0119] The glass transition temperature (Tg) of the polyalkylene carbonate according to the present invention is -10 to 50° C., 0 to 50° C., or 10 to 50° C. When the above range is satisfied, the polyalkylene carbonate may have excellent processability at room temperature.

[0120] According to another embodiment, when R1 to R8 in Formula 1 and Formula 2 above are each independently hydrogen, the glass transition temperature (Tg) of the polyalkylene carbonate may be 0°C to 20°C.

[0121] According to another embodiment, when R1 to R8 in Formula 1 and Formula 2 above are each independently a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, the glass transition temperature (Tg) of the polyalkylene carbonate may be 30°C to 50°C or 35°C to 50°C.

[0122] In addition, relative to the total weight of the polyalkylene carbonate according to the present invention, the cyclic carbonate content may be 0.5 wt % to 15.0 wt %, 0.5 wt % to 10.0 wt % or 0.5 wt % to 5.0 wt %. When the above range is met, the problem of glass transition temperature reduction caused by the cyclic carbonate acting as a softener can be minimized to exhibit excellent mechanical properties.

[0123] Cyclic carbonate content can be by using1H-NMR spectrometer (500MHz spectrometer, Jeol Inc.), 10mg of polyalkylene carbonate resin sample is dissolved in chloroform-d6 solvent and is measured.Specifically, according to1H-NMR spectrometer measurement result, near 4.5ppm, peak occurs, and this is cyclic carbonate peak, thus, by utilizing carbonate peak area and ether peak area, cyclic carbonate content can be calculated as shown in equation 2 below.

[0124] [Equation 2]

[0125] (A / N) / {(A / N)+[(B+C) / (1-CO2 content)]}

[0126] In Equation 2 above, A, B, C, N and CO2 content can be defined as follows.

[0127] A is the cyclic carbonate peak area, B is the carbonate peak area, C is the ether peak area, N is the molar mass of alkylene oxide divided by (44 + molar mass of alkylene oxide), and the CO2 content is (molar fraction of carbonate units × 44) divided by [(molar fraction of carbonate units × 44) + (molar mass of alkylene oxide × 100)].

[0128] Chain Extender

[0129] According to one embodiment of the present invention, the chain extender reacts with the polyalkylene carbonate polymer chain end or the end generated by thermal decomposition to connect the polymer chain, and the chain extender may be included in the polyalkylene carbonate resin composition in an amount of 0.01 to 3.00 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

[0130] In addition, the chain extender may be at least any one selected from 2,2′-(1,3-phenylene)bis-2-oxazoline, 2,2′-bis(2-oxazoline), and a compound represented by Formula 1 below.

[0131] [Formula 1]

[0132]

[0133] In the above formula 1,

[0134] R1 to R5 are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,

[0135] R6 is an alkyl group having 1 to 10 carbon atoms,

[0136] p, q and r are each independently a real number of 1 to 20.

[0137] additive

[0138] According to one embodiment of the present invention, the polyalkylene carbonate resin composition may include at least one additive selected from the group consisting of an organic acid and an acid anhydride, and the additive may be used to deactivate a catalyst.

[0139] The additive may be included in the polyalkylene carbonate resin composition in an amount of 0.001 parts by weight to 5.000 parts by weight or 0.05 parts by weight to 0.1 parts by weight, relative to 100 parts by weight of the polyalkylene carbonate.

[0140] When the additive is included in the above range, the catalyst can be effectively deactivated without the problem of accelerated thermal decomposition, and thus, the thermal stability of the composition can be effectively improved.

[0141] Meanwhile, in the polyalkylene carbonate resin composition according to one embodiment of the present invention, when an organic acid and anhydride are included together as additives, the content of the organic acid and the anhydride may fall within the above-mentioned additive content range, and then, there is no specific limitation on the ratio of the organic acid and the anhydride, but the weight ratio thereof may be, for example, 1:0.1 to 20.0 or 1:0.4 to 10.

[0142] In addition, the organic acid may be at least any one selected from the group consisting of citric acid, tartaric acid, ascorbic acid, and maleic acid.

[0143] In addition, the acid anhydride may be a dicarboxylic anhydride having a carbon number of 4 to 8, and specifically, may be at least any one selected from maleic anhydride, phthalic anhydride, and succinic anhydride.

[0144] Polyalkylene carbonate resin composition

[0145] The polyalkylene carbonate resin composition according to one embodiment of the present invention may have a molecular weight variation rate defined by the following Equation 1 equal to or less than 35%.

[0146] [Equation 1]

[0147] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 )×100

[0148] In Equation 1, M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, M W2 is the weight average molecular weight of the polyalkylene carbonate resin composition after heat treatment at 180° C. for 20 minutes as measured by gel chromatography.

[0149] In addition, the polyalkylene carbonate resin composition according to one embodiment of the present invention may include the additive and the chain extender in a weight ratio of 1: 0.1 to 20.0, specifically 1: 1 to 10. When the additive and the chain extender are included in the polyalkylene carbonate resin composition in the weight ratio, the organic acid and / or the acid anhydride may increase the reactivity of the chain extender, thereby more advantageously connecting the polymer chain ends.

[0150] In addition, the polyalkylene carbonate resin composition according to one embodiment of the present invention may further include an antioxidant as needed, and according to another embodiment, may further include 0.01 to 3.00 parts by weight of an antioxidant.

[0151] When the polyalkylene carbonate resin composition further includes an antioxidant, decomposition of polymer chains caused by free radicals can be prevented, thereby being more conducive to improvement of thermal stability.

[0152] In addition, the antioxidant can be selected from tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]methane, triethylene glycol-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate , at least any one of 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 2,4-di-tert-amyl-6-1-(3,5-di-tert-amyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, α-tocopherol and 2,6-di-tert-butyl-p-cresol.

[0153] Meanwhile, since the polyalkylene carbonate resin composition according to one embodiment of the present invention is prepared in the preparation method described later without the steps of adding and removing the chain extender, organic acid and / or acid anhydride, the content of the chain extender, organic acid and / or acid anhydride in the polyalkylene carbonate resin composition may be the same as the amount added during preparation.

[0154] According to another embodiment, the content of the chain extender, organic acid and / or anhydride in the polyalkylene carbonate resin composition according to the present invention can be confirmed by a component quantitative analysis method known in the art, and quantitative analyzers such as UPLC / MS / MS, HPLC / RI and UPLC-QTOF / MS can be exemplarily used.

[0155] In addition, there is no difference between the amount of organic acid, antioxidant, hydrolysis inhibitor and / or fatty acid metal salt added when preparing the polyalkylene carbonate resin composition and their contents analyzed using a quantitative analyzer, or the difference is within the error range (±10%).

[0156] Method for preparing polyalkylene carbonate resin composition

[0157] The present invention provides a method for preparing the polyalkylene carbonate resin composition.

[0158] A method for preparing a polyalkylene carbonate resin composition according to one embodiment of the present invention includes: a step (S1) of preparing a polymer containing polyalkylene carbonate by polymerizing an alkylene oxide compound with carbon dioxide in a solvent in the presence of a catalyst; a step (S2) of adding at least one additive selected from an organic acid, an antioxidant and a hydrolysis inhibitor to the polymer and stirring; and a step (S3) of removing the solvent.

[0159] Here, the preparation method according to one embodiment of the present inventive concept does not include an additional process for removing the catalyst such as extraction or precipitation, and thus, the polymer contains the catalyst.

[0160] Hereinafter, the method will be divided into multiple steps and will be described in more detail.

[0161] Step (S1)

[0162] Step (S1) is a step of forming a polyalkylene carbonate and preparing a polymer containing the same, and can be performed by polymerizing an alkylene oxide compound with carbon dioxide in a solvent in the presence of a catalyst.

[0163] The catalyst includes a double metal cyanide compound and a complexing agent, and the double metal cyanide compound and the complexing agent may be used without limitation as long as they are conventional in the art.

[0164] Illustratively, the double metal cyanide compound may be derived from a metal cyanide complex salt and a metal salt, and the metal cyanide complex salt may be water-soluble. Specifically, the metal cyanide complex salt may be represented by Formula 10 below.

[0165] [Formula 10]

[0166] Y a M'(CN) b

[0167] In the above formula 10, M' can be at least one selected from Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III), Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(V) and V(IV), preferably, at least one selected from Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III) and Ni(II). Y is an alkali metal ion or an alkaline earth metal ion. a is an integer from 1 to 4, b is an integer from 4 to 6, and a and b are selected so that the metal cyanide complex salt is electrically neutral.

[0168] As another example, the metal cyanide complex salt may be potassium hexacyanocobaltate (III), potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), calcium hexacyanocobaltate (III) or lithium hexacyanoiridate (III), preferably, potassium hexacyanocobaltate (III).

[0169] The metal salt may be water-soluble. Specifically, the metal salt may be represented by the following Formula 11.

[0170] [Formula 11]

[0171] M(X) n

[0172] In the above formula 11, M can be a transition metal, preferably, it can be at least one selected from Zn (II), Fe (II), Ni (II), Mn (II), Co (II), Sn (II), Pb (II), Fe (III), Mo (IV), Mo (VI), Al (III), V (V), V (IV), Sr (II), W (IV), W (VI), Cu (II) and Cr (III), more preferably, it can be at least one selected from Zn (II), Fe (II), Co (II) and Ni (II). X is an anion selected from halides, hydroxides, sulfates, carbonates, cyanates, oxalates, thiocyanates, isocyanates, isothiocyanates, carboxylates and nitrates. n is a value satisfying the valence state of M.

[0173] As another example, the metal salt can be zinc (II) chloride, zinc (III) chloride, zinc bromide, zinc iodide, zinc acetate, zinc acetylacetonate, zinc benzoate, zinc nitrate, iron (II) sulfate, iron (II) bromide, cobalt (II) chloride, cobalt (II) thiocyanate, nickel (II) formate, nickel (II) nitrate and mixtures thereof, preferably, zinc (II) chloride, zinc (III) chloride, zinc bromide or zinc iodide.

[0174] The catalyst according to the present invention can be represented by Formula 12 below.

[0175] [Formula 12]

[0176] M 2 p [M 1 (CN)6] q ·dM 2 (X)r·eL·fH2O

[0177] In the above formula 12, M 1 and M 2 Each is independently a transition metal, X is an anion, and L is cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol or cyclooctanol. p, q, d, r, e and f are each independently an integer from 1 to 6.

[0178] More specifically, the catalyst according to the present invention can be represented by Formula 13 below.

[0179] [Formula 13]

[0180] Zn3[Co(CN)6]2·gZnCl2·hL·iH2O

[0181] In the above Formula 13, L is cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol or cyclooctanol, and g, h and i are each independently an integer of 1 to 6.

[0182] In addition, the complexing agent may be used without particular limitation as long as it is commonly used in the art, but may illustratively be at least any one selected from ethanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert-butanol.

[0183] According to another embodiment, the complexing agent may be a compound represented by Formula 14 below.

[0184] [Formula 14]

[0185]

[0186] In the above formula 14, R 9a and R 9b are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, and R 9a and R 9b at least one of which is an alkylene group having 1 to 5 carbon atoms,

[0187] R 9c and R 9d are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,

[0188] n is an integer from 0 to 2.

[0189] Specifically, in the above formula 14, R 9a and R 9b are each independently a single bond or an alkylene group having 1 to 3 carbon atoms, R 9a and R 9b At least one of them is an alkylene group having 1 to 3 carbon atoms, R 9c and R 9d Each is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 to 2.

[0190] As another example, in Formula 14 above, R 9a and R 9b are each independently a single bond or an alkylene group having 1 to 3 carbon atoms, R 9a and R 9b At least one of them may be an alkylene group having a carbon number of 1 to 3, R 9c is a hydrogen atom, and n can be 0.

[0191] As another example, the complexing agent may be a cycloalkyl alcohol having 3 to 12 carbon atoms, and specifically, may be a cycloalkyl alcohol having 4 to 10 carbon atoms or 5 to 7 carbon atoms.

[0192] More specifically, the complexing agent can be selected from cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-propylcyclopentanol, 2-propylcyclopentanol, 3-propylcyclopentanol, 1-butylcyclopentanol, 2-butylcyclopentanol, 3-butylcyclopentanol, 1-isopropylcyclopentanol, 2-isopropylcyclopentanol, 3-isopropylcyclopentanol, 1-(prop-2-yl)cyclopentanol, 2,2-dimethylcyclopentanol, 2,3-dimethylcyclopentanol, 3,3-dimethylcyclopentanol, 1,2-dimethylcyclopentanol, 1,3-dimethylcyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol, 1-propylcyclohexanol, 1-butylcyclohexanol, 2-methylcyclopentanol, 3-butylcyclopentanol, 1-isopropylcyclopentanol, 2-isopropylcyclopentanol, 3-isopropylcyclopentanol, 1-(prop-2-yl)cyclopentanol, -1-cyclohexanol, 2-ethyl-1-cyclohexanol, 3-ethyl-1-cyclohexanol, 4-ethyl-1-cyclohexanol, 2-propyl-1-cyclohexanol, 3-propyl-1-cyclohexanol, 4-propyl-1-cyclohexanol, 2-butyl-1-cyclohexanol, 3-butyl-1-cyclohexanol, 4-butyl-1-cyclohexanol, 2-isopropyl-1-cyclohexanol, 3-isopropyl-1-cyclohexanol, At least any one of 4-isopropyl-1-cyclohexanol, 2-tert-butyl-1-cyclohexanol, 3-tert-butyl-1-cyclohexanol, 4-tert-butyl-1-cyclohexanol, 2,3-dimethyl-1-cyclohexanol, 2,4-dimethyl-1-cyclohexanol, 3,4-dimethyl-1-cyclohexanol, 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol and 4-methylcycloheptanol. Specifically, the complexing agent can be at least any one selected from cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol and cyclooctanol.

[0193] According to another embodiment, the complexing agent may be at least any one selected from cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, and cyclooctanol.

[0194] At the same time, when the catalyst contains a compound represented by Formula 14 as a complexing agent, a cycloalkane-type alcohol having a bulky structure can be used as a complexing agent, so that the catalyst can have various crystal structures, for example, cubic, amorphous, monoclinic, etc., thereby increasing the proportion of repeating units containing carbon dioxide in the polyalkylene carbonate prepared by appropriately controlling the reaction rate of the epoxy compound and the carbon dioxide, and reducing the content of cyclic carbonate as a by-product, thereby obtaining a polyalkylene carbonate having more excellent thermal stability and excellent processing properties.

[0195] In addition, the catalyst may further include a complexing aid, which may be a compound having a hydroxyl group, an amine group, an ester group, or an ether group at its terminal.

[0196] The complexing aid can improve the activity of the catalyst and can be, for example, at least one selected from polyacrylamide, poly(acrylamide-co-acrylic acid), polyacrylic acid, poly(acrylic acid-co-maleic acid), polyacrylonitrile, polyalkyl acrylates, polyalkyl methacrylates, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl acetate, polyvinyl alcohol, poly-N-vinyl pyrrolidone, poly(N-vinyl pyrrolidone-co-acrylic acid), polyvinyl methyl ketone, poly(4-vinylphenol), poly(acrylic acid-co-styrene), oxazoline polymers, polyalkylene imines, maleic acid, maleic anhydride copolymers, hydroxyethyl cellulose, polyacetals, glycidyl ethers, glycosides, carboxylates of polyols, gallic acid, esters and amides.

[0197] In addition, the complexing aid may be a compound prepared by ring-opening polymerization of a cyclic ether compound, an epoxy polymer or an oxetane polymer, and may be, for example, at least any one selected from polyethers, polyesters, polycarbonates, polyalkylene glycols, polyalkylene glycol sorbitan esters and polyalkylene glycol glycidyl ethers.

[0198] In addition, there is no particular limitation on the polymerization, but preferably, it can be performed as solution polymerization. Solution polymerization can appropriately control the heat of reaction, and can easily control the weight average molecular weight or viscosity of the polyalkylene carbonate to be obtained.

[0199] The catalyst and the alkylene oxide compound may be used in a weight ratio of 1:100 to 1:8000, 1:300 to 1:6000, or 1:1000 to 1:4000. Within the above range, there are effects that high activity of the catalyst can be exhibited and by-products can be minimized, and the back-biting phenomenon of the prepared polyalkylene carbonate caused by heating can be minimized.

[0200] In addition, the polymerization of the alkylene oxide compound and carbon dioxide may be performed within a temperature range of 30° C. to 120° C., 40° C. to 110° C., or 50° C. to 100° C. When the above range is satisfied, the polymerization time of the alkylene oxide compound and carbon dioxide may be controlled within 24 hours, thereby improving preparation productivity.

[0201] In addition, the polymerization of the alkylene oxide compound and the carbon dioxide can be carried out in the pressure range of 5 bar to 50 bar, 10 bar to 40 bar or 15 bar to 30 bar. When the above range is met, the effect is that the ratio of the repeating unit containing carbon dioxide in the prepared polyalkylene carbonate resin is high, and the content of the cyclic carbonate as a by-product can be reduced.

[0202] The alkylene oxide compound may be at least any one selected from the following: an alkylene oxide having 2 to 20 carbon atoms which is unsubstituted or substituted with a halogen or an alkyl group having 1 to 5 carbon atoms; a cyclic alkylene oxide having 4 to 20 carbon atoms which is unsubstituted or substituted with a halogen or an alkyl group having 1 to 5 carbon atoms; and styrene oxide having 8 to 20 carbon atoms which is unsubstituted or substituted with a halogen or an alkyl group having 1 to 5 carbon atoms, and may be, for example, at least any one selected from the following: ethylene oxide, propylene oxide, butylene oxide, pentane oxide, hexane oxide, octane oxide, decane oxide, dodecane oxide, tetradecane oxide, hexadecane oxide, octadecane oxide, butadiene monoxide, 1,2-epoxy-7-octene, epifluoropropane, cyclopentane oxide, Oxychloropropane, epibromopropane, isopropyl glycidyl ether, butyl glycidyl ether, tert-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, cyclopentane oxide, cyclohexane oxide, cyclooctane oxide, cyclododecane oxide, α-pinene oxide, 2,3-epoxynorbornene, limonene oxide, dieldrin, 2,3-epoxypropylbenzene, styrene oxide, phenylpropylene oxide, styrene oxide, chlorostilbene oxide, dichlorostilbene oxide, 1,2-epoxy-3-phenoxypropane, benzyloxymethyl oxirane, glycidyl-methyl phenyl ether, chlorophenyl-2,3-epoxypropyl ether, glycidyl methoxyphenyl ether, biphenyl glycidyl ether and glycidyl naphthyl ether.

[0203] In addition, when the solution polymerization of the alkylene oxide compound and carbon dioxide is carried out, the alkylene oxide compound and the solvent can be mixed, and the solvent can be at least any one selected from the following: dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, chloroform, acetonitrile, propionitrile, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, nitromethane, 1,3-dioxane, 1,4-dioxane, hexane, toluene, tetrahydrofuran, methyl ethyl ketone, methylamine, methyl isobutyl ketone, acetone, cyclohexanone, trichloroethylene, methyl acetate, vinyl acetate, ethyl acetate, propyl acetate, butyrolactone, caprolactone, nitropropane, benzene, styrene, xylene and methyl propasol.

[0204] The solvent and the alkylene oxide compound may be used in a weight ratio of 1:0.1 to 1:100, 1:1 to 1:100, or 1:1 to 1:10. Since the solvent can appropriately serve as a reaction medium within this range, there is an effect that the productivity of the polyalkylene carbonate resin can be improved and by-products generated in the preparation process can be minimized.

[0205] Step (S2)

[0206] Step (S2) is a step of adding a chain extender and at least one additive selected from an organic acid and an acid anhydride to a polymer comprising the prepared polyalkylene carbonate and stirring.

[0207] At least one additive selected from organic acids and anhydrides may be added in an amount of 0.001 to 5.000 parts by weight relative to 100 parts by weight of the polyalkylene carbonate solid content in the polymer, and specific examples of the organic acid and anhydride are the same as described above.

[0208] In addition, the chain extender may be added in an amount of 0.01 parts by weight to 3.00 parts by weight relative to 100 parts by weight of the solid content of the polyalkylene carbonate, and specific examples of the chain extender are the same as described above.

[0209] According to another embodiment, in step (S2), an antioxidant may be further added to the polymer, in which case the antioxidant may be added in an amount of 0.01 to 3.00 parts by weight relative to 100 parts by weight of the polyalkylene carbonate solid content in the polymer, and specific examples of the antioxidant are the same as described above.

[0210] Additionally, stirring may be performed without significant limitation as long as mixing is performed so that the organic acid is evenly distributed in the polymer.

[0211] Meanwhile, before adding the chain extender, the organic acid and / or the acid anhydride, a step of additionally adding a solvent to the polymer so that the solid content of the polyalkylene carbonate in the polymer is 10 wt % to 40 wt % may be further performed, and in this case, the viscosity of the polymer may be reduced to more uniformly mix the organic acid and / or the acid anhydride in the polymer. In this case, the solvent may be the same as the solvent used in step (S1), or may be at least any one selected from the above solvents.

[0212] In addition, since the preparation method according to one embodiment of the present invention does not include an additional process such as extraction or precipitation for removing the catalyst component after polymerization, it has effects such as improved economic efficiency and productivity due to simple processes and reduced costs for additional processes.

[0213] Step (S3)

[0214] Step (S3) is a step of preparing a polyalkylene carbonate resin composition by removing the solvent.

[0215] Here, the solvent removal may be performed by a conventional method in the art without particular limitation as long as the solvent is removed, and may be performed by heating, for example, at a temperature of 30° C. to 150° C. for 30 minutes to 10 hours.

[0216] Example

[0217] Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples merely illustrate the present invention, and the scope of the present invention is not limited thereto.

[0218] Preparation Example

[0219] The first mixed solution was prepared by mixing 11.45g of zinc chloride, 30ml of distilled water and 39g of cyclohexanol in a 500ml beaker. The second mixed solution was prepared by dissolving 4g of potassium hexacyanocobaltate in 100ml of distilled water in a 250ml beaker. The third mixed solution was prepared by dissolving 5g of polypropylene glycol (Mw=3000) and 23g of cyclohexanol in 2ml of distilled water in a 100ml beaker. Using a mechanical stirrer, the second mixed solution was added dropwise to the first mixed solution at 25°C for 1 hour, and then the third mixed solution was immediately added and reacted for 1 hour. Afterwards, a high-speed centrifuge was used to separate the mixed product, and the separated precipitate was washed twice with a mixture of 70ml of distilled water and 70ml of cyclohexanol. After that, after additional washing with 140 ml of cyclohexanol, the washed precipitate was dried in a vacuum oven at 80° C. for 12 hours, and finally 6.2 g of a double metal cyanide catalyst was obtained.

[0220] Example 1

[0221] 10 mg of the double metal cyanide catalyst prepared in the preparation example, 20 g of ethylene oxide and 10 g of dioxolane solvent were placed in a high pressure reactor. Afterwards, carbon dioxide was added to the reactor and the reactor was pressurized to 30 bar. The polymerization reaction was carried out at 70° C. for 24 hours. After the reaction was completed, the unreacted carbon dioxide was removed and a polymer containing polyethylene carbonate was prepared. Afterwards, the polymer was diluted with a dioxolane solvent so that the polyethylene carbonate solid content in the polymer reached 20% by weight. Then, 0.1 parts by weight of 2,2′-(1,3-phenylene)bis-2-oxazoline and 0.5 parts by weight of maleic anhydride were added as chain extenders relative to 100 parts by weight of the polyalkylene carbonate solid content, stirred, poured into a tray, and dried in a vacuum oven at 40° C. for 6 hours to prepare a polyethylene carbonate resin composition. At this time, the catalyst components remaining in the composition were Co=80ppm and Zn=165ppm.

[0222] Example 2

[0223] In the above Example 1, a polyethylene carbonate resin composition was prepared in the same manner as Example 1 except that 0.5 parts by weight of a chain extender was added. At this time, the residual catalyst component in the composition had the same level as that of Example 1.

[0224] Example 3

[0225] In the above Example 1, a polyethylene carbonate resin composition was prepared in the same manner as Example 1 except that 0.5 parts by weight of a chain extender was added and 0.1 parts by weight of citric acid was added instead of maleic anhydride. At this time, the residual catalyst component in the composition had the same level as that of Example 1.

[0226] Example 4

[0227] In the above Example 3, in addition to adding 0.5 parts by weight of an antioxidant relative to 100 parts by weight of the solid content of polyethylene carbonate, (SONGWON Inc.), a polyethylene carbonate resin composition was prepared in the same manner as in Example 3. At this time, the catalyst component remaining in the composition had the same level as in Example 3.

[0228] Example 5

[0229] In the above Example 1, in addition to adding 0.1 parts by weight of A polyethylene carbonate resin composition was prepared in the same manner as in Example 1 except that 4468 (BASF Inc.) was added. At this time, the level of the catalyst component remaining in the composition was the same as that in Example 1.

[0230] Example 6

[0231] In the above Example 5, in addition to adding 0.5 parts by weight of A polyethylene carbonate resin composition was prepared in the same manner as in Example 5 except that 4468 (BASF Inc.) was added. At this time, the level of the catalyst component remaining in the composition was the same as that in Example 5.

[0232] Example 7

[0233] In the above Example 5, in addition to adding 1.0 weight part of A polyethylene carbonate resin composition was prepared in the same manner as in Example 5 except that 4468 (BASF Inc.) was added. At this time, the level of the catalyst component remaining in the composition was the same as that in Example 5.

[0234] Example 8

[0235] In the above Example 6, in addition to 100 parts by weight of the polyethylene carbonate solid content, 0.5 parts by weight of (SONGWON Inc.), a polyethylene carbonate resin composition was prepared in the same manner as in Example 6. At this time, the catalyst component remaining in the composition had the same level as in Example 6.

[0236] Example 9

[0237] In the above Example 6, a polyethylene carbonate resin composition was prepared in the same manner as in Example 6, except that 0.05 parts by weight of tartaric acid was added instead of maleic anhydride relative to 100 parts by weight of the polyethylene carbonate solid content. At this time, the residual catalyst component in the composition had the same level as in Example 6.

[0238] Example 10

[0239] In the above Example 6, a polyethylene carbonate resin composition was prepared in the same manner as in Example 6 except that 0.5 parts by weight of maleic acid was added instead of maleic anhydride relative to 100 parts by weight of the polyethylene carbonate solid content. At this time, the residual catalyst component in the composition had the same level as in Example 6.

[0240] Embodiment 11

[0241] In the above Example 6, a polyethylene carbonate resin composition was prepared in the same manner as in Example 6, except that 0.3 parts by weight of ascorbic acid was added instead of maleic anhydride relative to 100 parts by weight of the polyalkylene carbonate solid content. At this time, the residual catalyst component in the composition had the same level as in Example 6.

[0242] Comparative Example 1

[0243] In the above Example 1, a polyethylene carbonate resin composition was prepared in the same manner as in Example 1 except that maleic anhydride was not added. At this time, the catalyst component remaining in the composition had the same level as in Example 1.

[0244] Comparative Example 2

[0245] In the above Example 6, a polyethylene carbonate resin composition was prepared in the same manner as in Example 6 except that maleic anhydride was not added. At this time, the catalyst component remaining in the composition had the same level as in Example 6.

[0246] Comparative Example 3

[0247] In the above Example 1, a polyethylene carbonate resin composition was prepared in the same manner as in Example 1 except that the chain extender was not added. At this time, the catalyst component remaining in the composition had the same level as in Example 1.

[0248] Test example

[0249] The molecular weight characteristics and thermal stability of the polyalkylene carbonate resin compositions prepared in the above examples and comparative examples were compared and analyzed. The results are shown in Tables 1 and Figure 1 middle.

[0250] (1) Molecular weight characteristics

[0251] The molecular weight characteristics were analyzed by gel permeation chromatography (GPC) using polystyrene as a standard material.

[0252] Column: Two Agilent PLgel MIXED-B (7.5 mm × 300, 10 μm)

[0253] Solvent: Chloroform

[0254] Flow rate: 0.7ml / min

[0255] Column temperature: 40°C

[0256] Sample: 4.0 mg / 1.0 ml of chloroform

[0257] Injection volume: 20 μl

[0258] Standard material: Polystyrene

[0259] In addition, the molecular weight characteristics were measured before and after the heat treatment of the polyalkylene carbonate resin composition, and the molecular weight change rate was confirmed according to Equation 1 below.

[0260] [Equation 1]

[0261] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 )×100

[0262] In equation 1,

[0263] M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, M W2 is the weight average molecular weight of the polyalkylene carbonate resin composition after heat treatment at 180° C. for 20 minutes as measured by gel chromatography.

[0264] (2) Thermal stability

[0265] The mass change analysis was measured using a thermogravimetric analyzer (TGA), and the temperature at which a mass loss of 5% by weight relative to the mass at 30° C. occurred before the temperature increase in the following fifth step was recorded as the thermal decomposition temperature.

[0266] Specifically, mass change analysis was measured using a thermogravimetric analyzer (TGA2, Mettler Toledo) in the following steps.

[0267] 1) Step 1: Increase the temperature from 30°C to 150°C (10°C / min)

[0268] 2) Step 2: Keep at 150°C for 5 minutes

[0269] 3) Step 3: Reduce the temperature from 150°C to 30°C (10°C / min)

[0270] 4) Step 4: Keep at 30°C for 5 minutes

[0271] 5) Step 5: Increase the temperature from 30°C to 400°C (10°C / min)

[0272] [Table 1]

[0273]

[0274]

[0275] As shown in Table 1 and Figure 1 As shown in, it can be confirmed that the polyalkylene carbonate resin composition according to Examples 1 to 11 has a molecular weight change rate of less than 35% and a higher thermal decomposition temperature compared with the comparative example. Specifically, the molecular weight change rate of the polyalkylene carbonate resin composition according to Examples 1 to 11 is 34% to 66% of the molecular weight change rate of the polyalkylene carbonate resin composition according to Comparative Example 1 and Comparative Example 2 without an additive (organic acid or anhydride), thereby significantly reducing the molecular weight change caused by heat treatment, and the thermal decomposition temperature of the polyalkylene carbonate resin composition according to Examples 2, 4 and 6 is 132% to 139% and 118% to 125% of the thermal decomposition temperature of the polyalkylene carbonate resin composition according to Comparative Example 1 and Comparative Example 2. In addition, the molecular weight change rate of the polyalkylene carbonate resin composition according to Examples 1 to 11 is 38% to 74% of the molecular weight change rate of the polyalkylene carbonate resin composition according to Comparative Example 3 without a chain extender. Therefore, it can be confirmed that the polyalkylene carbonate resin composition according to the present invention includes the chain extender and the additive, thereby suppressing thermal decomposition and significantly improving thermal stability.

Claims

1. A polyalkylene carbonate resin composition comprising: Polyalkylene carbonates; chain extenders; and At least one additive selected from organic acids and acid anhydrides.

2. The polyalkylene carbonate resin composition according to claim 1, wherein The additive may be included in an amount of 0.001 to 5.000 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

3. The polyalkylene carbonate resin composition according to claim 1, wherein The organic acid is at least any one selected from citric acid, tartaric acid, ascorbic acid and maleic acid.

4. The polyalkylene carbonate resin composition according to claim 1, wherein The acid anhydride is a dicarboxylic acid anhydride having 4 to 8 carbon atoms.

5. The polyalkylene carbonate resin composition according to claim 1, wherein The content of the chain extender is 0.01 parts by weight to 3.00 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

6. The polyalkylene carbonate resin composition according to claim 1, wherein The chain extender is at least any one selected from 2,2′-(1,3-phenylene)bis-2-oxazoline, 2,2′-bis(2-oxazoline) and a compound represented by the following Formula 1: [Formula 1] wherein R1 to R5 are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R6 is an alkyl group having 1 to 10 carbon atoms, p, q and r are each independently a real number of 1 to 20.

7. The polyalkylene carbonate resin composition according to claim 1, wherein The additive and the chain extender are included in a weight ratio of 1:0.1 to 20.

0. The polyalkylene carbonate resin composition according to claim 1 , further comprising an antioxidant.

9. The polyalkylene carbonate resin composition according to claim 1, wherein The invention further includes 0.01 to 3.00 parts by weight of an antioxidant relative to 100 parts by weight of the polyalkylene carbonate.

10. The polyalkylene carbonate resin composition according to claim 8 or 9, wherein The antioxidant is selected from tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, triethylene glycol-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, At least any one of 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 2,4-di-tert-amyl-6-1-(3,5-di-tert-amyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, α-tocopherol and 2,6-di-tert-butyl-p-cresol.

11. The polyalkylene carbonate resin composition according to claim 1, wherein The molecular weight change rate defined by the following equation 1 is equal to or less than 35%: [Equation 1] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 )×100 Among them, M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, M W2 is the weight average molecular weight of the polyalkylene carbonate resin composition after heat treatment at 180° C. for 20 minutes as measured by gel chromatography.

12. The polyalkylene carbonate resin composition according to claim 1, wherein The polyalkylene carbonate includes a repeating unit represented by the following Formula 2 and a repeating unit represented by the following Formula 3: [Formula 2] [Formula 3] wherein R1 to R8 are each independently hydrogen, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, * refers to the connection site between repeating units, x and y are mole fractions, x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

13. The polyalkylene carbonate resin composition according to claim 1, wherein The polyalkylene carbonate is at least any one selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polypentylene carbonate, polyhexylene carbonate, polyoctylene carbonate and polycyclohexylene carbonate.

14. A method for preparing a polyalkylene carbonate resin composition, the method comprising: Step S1, preparing a polymer containing polyalkylene carbonate by polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst; Step S2, adding a chain extender and at least one additive selected from organic acids and acid anhydrides to the polymer, and stirring; and Step S3, removing the solvent.

15. The method according to claim 14, wherein: In step S2, the additive is added in an amount of 0.001 parts by weight to 5.000 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

16. The method according to claim 14, wherein: In step S2, the additive and the chain extender are included in a weight ratio of 1:0.1 to 20.

0.

17. The method according to claim 14, wherein: In step S2, before adding the chain extender and the additives to the polymer, a solvent is additionally added to the polymer so that the solid content of the polyalkylene carbonate in the polymer is 10 wt % to 40 wt %.

18. The method according to claim 14, wherein: In step S2, an antioxidant is further added to the polymer.

19. The method according to claim 14, wherein: The catalyst comprises a double metal cyanide compound and a complexing agent.

20. The method according to claim 19, wherein: The complexing agent is selected from cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-propylcyclopentanol, 2-propylcyclopentanol, 3-propylcyclopentanol, 1-butylcyclopentanol, 2-butylcyclopentanol, 3-butylcyclopentanol, 1-isopropylcyclopentanol, 2-isopropylcyclopentanol, 3-isopropylcyclopentanol, 1-(prop-2-yl)cyclopentanol, 2,2-dimethylcyclopentanol, 2,3-dimethylcyclopentanol, 3,3-dimethylcyclopentanol, 1,2-dimethylcyclopentanol, 1,3-dimethylcyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol, 1-propylcyclohexanol, 1-butylcyclohexanol, 2-methyl-1 -cyclohexanol, 2-ethyl-1-cyclohexanol, 3-ethyl-1-cyclohexanol, 4-ethyl-1-cyclohexanol, 2-propyl-1-cyclohexanol, 3-propyl-1-cyclohexanol, 4-propyl-1-cyclohexanol, 2-butyl-1-cyclohexanol, 3-butyl-1-cyclohexanol, 4-butyl-1-cyclohexanol, 2-isopropyl-1-cyclohexanol, 3-isopropyl-1-cyclohexanol, 4-isopropyl-1-cyclohexanol, 2-tert-butyl-1-cyclohexanol, 3-tert-butyl-1-cyclohexanol, 4-tert-butyl-1-cyclohexanol, 2,3-dimethyl-1-cyclohexanol, 2,4-dimethyl-1-cyclohexanol, 3,4-dimethyl-1-cyclohexanol, 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol and 4-methylcycloheptanol.

Images