KR20160057929A - Polyalkylene carbonate resin with improved thermal stability - Google Patents

Abstract

The present invention relates to a polyalkylene carbonate resin. More specifically, provided is a polyalkylene carbonate resin which exhibits biodegradability while having high molecular weight and improved thermal stability. To this end, the polyalkylene carbonate resin includes each of repeating units represented by chemical formula 1, 2, and 3.

Description

POLYLKYLENE CARBONATE RESIN WITH IMPROVED THERMAL STABILITY TECHNICAL FIELD The present invention relates to a polyalkylene carbonate resin having improved thermal stability,

The present invention relates to polyalkylene carbonate resins having improved thermal stability.

Since the Industrial Revolution, mankind has built a modern society by consuming a large amount of fossil fuels, while increasing the atmospheric carbon dioxide concentration and further promoting this increase by environmental destruction such as deforestation. Since global warming is caused by the increase of greenhouse gases such as carbon dioxide in the atmosphere and freon or methane, it is very important to reduce the atmospheric concentration of carbon dioxide which contributes to global warming. Are being carried out on a global scale.

Among them, the copolymerization reaction of carbon dioxide and epoxide found by Inoue et al. Is expected as a reaction to solve the problem of global warming. It is actively studied not only in terms of fixation of chemical carbon dioxide but also in the use of carbon dioxide as carbon resources . Particularly, in recent years, the polyalkylene carbonate resin obtained by the polymerization of carbon dioxide and epoxide is widely regarded as a kind of biodegradable resin.

However, the polyalkylene carbonate resin is basically a linear structure resin having biodegradability and has a problem of poor thermal stability. In particular, when such a polyalkylene carbonate resin is thermally cured for application to a product, or when such a resin product is exposed to heat, the main chain of the resin can be decomposed by back-biting or the like. This serves as an obstacle to the application of the polyalkylene carbonate resin to a wider variety of uses.

In order to improve the physical properties of the polyalkylene carbonate resin, it is desired to improve the dispersibility of the catalyst (Patent Document 1), to control the molecular weight by adding an organic acid in the polymerization reaction (Patent Document 2) (Patent Document 3) Various techniques have been proposed.

However, even according to this method, there is still a limit such that the polymerization rate is saturated in the polymerization reaction of epoxide and carbon dioxide, the conversion rate is not further increased, and the amount of by-products is increased.

Japanese Patent No. 2732475 (December 26, 1997) US Patent No. 4943677 (Jul. 24, 1990) Japanese Patent Laid-Open No. 2007-126547 (May 24, 2007)

The present invention is to provide a polyalkylene carbonate resin having improved thermal stability.

Hereinafter, a polyalkylene carbonate resin according to embodiments of the present invention and a method for producing the same will be described in detail.

Prior to that, and unless explicitly stated throughout the present specification, the terminology is used merely to refer to a specific embodiment and is not intended to limit the present invention. And, the singular forms used herein include plural forms unless the phrases expressly have the opposite meaning. Also, as used herein, the term " comprises " embodies certain features, areas, integers, steps, operations, elements and / or components, It does not exclude the existence or addition of a group.

I. Polyalkylene Carbonate  Suzy

Generally, a point in time at which the polymerization rate saturates in the polymerization reaction and the conversion rate no longer increases is observed. And, if the polymerization is maintained above the saturation point of the polymerization rate, the production of by-products will increase sharply.

As a result of research conducted by the inventors of the present invention, it has been found that, when a polyalkylene carbonate resin (hereinafter, referred to as a 'PAC resin') is produced using an alkylene oxide and a cycloalkylene oxide as epoxides simultaneously, But the formation of byproducts can be remarkably suppressed.

That is, the PAC resin provided through the present invention is formed by ternary copolymerization of carbon dioxide, alkylene oxide and cycloalkylene oxide. In particular, according to the results of the present inventors' study, the PAC resin formed through the ternary copolymerization contains main repeating units of carbon dioxide and alkylene oxide, and the main repeating units are composed of repeating units of carbon dioxide and cycloalkylene oxide And has a connected structure. In other words, the repeating unit of carbon dioxide and cycloalkylene oxide functions as a linker connecting the main repeating units. Accordingly, the PAC resin satisfying such a structure can have a high molecular weight, which is difficult to attain only by polymerization of a common alkylene oxide with carbon dioxide, and thereby exhibit improved thermal stability and mechanical properties. The PAC resin has advantages of rheological properties and can be applied to various applications.

According to one embodiment of the invention,

And each repeating unit represented by the following general formula (1), (2) and (3)

Wherein the repeating unit represented by the above-mentioned formula (3) connects at least two repeating units represented by the above formula (1) or connects at least two repeating units formed by combination of the above-mentioned formula (1) and the formula (2)

[Chemical Formula 1]

(2)

(3)

In the above Formulas 1 to 3,

R ¹ and R ² are each independently an alkylene having 1 to 20 carbon atoms which is substituted or unsubstituted with halogen or an alkyl having 1 to 5 carbon atoms,

A is cycloalkylene having 4 to 12 carbon atoms,

p is an integer of 2 to 10,

Each R ⁱ is independently hydrogen or alkyl of 1 to 5 carbon atoms, adjacent R ^{i s} may be connected to each other to form an aliphatic ring,

n is an integer from 10 to 5,000,

( n + 1 ): m is 1: 0.05 to 1: 3.

PAC resins according to embodiments of the invention are formed by ternary copolymerization of carbon dioxide, alkylene oxide, and cycloalkylene oxide. In the ternary copolymerization process of carbon dioxide, alkylene oxide and cycloalkylene oxide, it is possible to form repeating units having various structures, wherein the repeating units represented by the formulas (1), (2) and (3) are representative repeating units. Wherein the repeating unit represented by the formula (1) is a main repeating unit formed by polymerization of an alkylene oxide with carbon dioxide. The repeating unit represented by the formula (2) is a repeating unit formed by polymerization of an alkylene oxide, and the repeating unit represented by the formula (3) is a repeating unit formed by polymerization of a cycloalkylene oxide with carbon dioxide.

In particular, according to the study results of the present inventors, it has been found that the repeating unit represented by the above-mentioned formula (3) is not located at the terminal of the resin, and at least two main repeating units represented by the above formula (1) Linker that connects at least two repeating units formed by a combination of two or more repeating units.

In this connection, a conventional PAC resin formed by copolymerization of an alkylene oxide and carbon dioxide has a limit of conversion ratio in the polymerization process, so that it is difficult to have a molecular weight exceeding a specific range, and when the polymerization is further maintained, the production of byproducts increases sharply do.

However, the PAC resin according to the embodiment of the present invention has repeating units represented by the above formula (3) which can not be observed in a conventional PAC resin due to simultaneous use of an alkylene oxide and a cycloalkylene oxide as epoxides in a specific ratio . In particular, the repeating unit represented by the above formula (3) may be obtained by connecting at least two main repeating units represented by the above formula (1) or connecting at least two repeating units formed by the combination of the above formula (1) Resin.

Thereby, the repeating units having a high molecular weight are linked by the repeating unit represented by the above-mentioned formula (3) to form a PAC resin having a higher molecular weight. Such a PAC resin can exhibit a higher molecular weight in a shorter period of time than the conventional PAC resin. Furthermore, the high molecular weight PAC resin formed in such a short period of time can exhibit a low content of byproducts, and in particular, can exhibit improved thermal stability and mechanical properties.

Specifically, in the general formulas (1) and (2), R ¹ and R ² are each independently alkylene having 1 to 20 carbon atoms, and the hydrogen contained in the alkylene may be substituted with halogen or alkyl having 1 to 5 carbon atoms have.

In Formula 3, A is a cycloalkylene having 4 to 12 carbon atoms, and each hydrogen included in the cycloalkylene may be substituted or unsubstituted with R ⁱ . That is, in Formula 3, p may be an integer of 2 to 10. In the formula (3), R ¹ is independently hydrogen or alkyl having 1 to 5 carbon atoms, and adjacent R ^{1 s} may be connected to each other to form an aliphatic ring.

As a non-limiting example, A may be one of the following formulas. Each hydrogen contained in the cycloalkylene of the following structural formula may be substituted or unsubstituted with alkyl having 1 to 5 carbon atoms, and adjacent alkyls may be connected to each other to form an aliphatic ring.

In the above formulas (1) to (3), the degree of polymerization n , m and l of the respective repeating units may be determined according to the content ratio of the monomers used for forming the PAC resin. For example, in Formula 1, n may be an integer of 10 to 5,000, preferably 500 to 2,500. That is, in order to ensure the molecular weight and the basic physical properties according to the main repeating unit represented by Formula 1, n is preferably an integer satisfying the range.

In the above formulas (1) to (3), ( n + 1 ): m may be 1: 0.05 to 1: 3, preferably 1: 0.1 to 1: 2.5. That is, it is preferable that the ( n + 1 ): m is 1: 0.05 or more in order to achieve the high molecular weight and the improvement of the thermal stability according to the introduction of the repeating unit of the formula (3). However, if the ratio of m is higher than necessary, the inherent biodegradability of the PAC resin may deteriorate, so that ( n + 1 ): m is preferably 1: 3 or less.

In the PAC resin according to the embodiment of the present invention, the presence of the repeating unit represented by the above formula (3) can be confirmed through NMR spectroscopy or the like.

For example, the PAC resin may represent a ¹ H NMR spectrum (300 MHz, CDCl ₃ ) having at least one peak at δ of 4.50 to 4.70 ppm. That is, the ¹ H NMR spectrum of the PAC resin shows that the peak along the -CH- located at the connecting site of -A- and -O- in the repeating unit of Formula 3 can be observed in the vicinity of 4.50 to 4.70 ppm have.

When the repeating unit represented by the above formula (3) is present at the end of the PAC resin, at least one peak derived from the cyclic structure should be identified at about 3.74 ppm. However, as can be seen from the examples, the PAC resin does not show a peak near 3.74 ppm. Through this NMR spectrum, it can be assumed that the repeating unit represented by the formula (3) is inserted as a linker in the polymer chain in the PAC resin.

In the ¹ H NMR spectrum of the PAC resin, the integrated value of the peak due to the repeating unit represented by the formula (2) relative to the integrated value of the peak due to the repeating unit represented by the above formulas (1) and (3) is 1: 1: 5, preferably 1: 0.1 to 1: 3.

Meanwhile, the PAC resin according to the embodiment of the present invention may have a high weight average molecular weight (Mw) of 50,000 to 1,000,000, preferably 300,000 to 950,000, as described above.

And, the PAC resin may have a polydispersity index (PDI) of 2 to 6, preferably 2.4 to 3.5.

The PAC resin may have a glass transition temperature (Tg) of 10 to 30 占 폚, preferably 10 to 25 占 폚.

Thus, the PAC resin according to the embodiment of the present invention can have a high molecular weight, which is difficult to achieve by the conventional polymerization of an alkylene oxide with carbon dioxide alone, and thus can exhibit improved thermal stability and mechanical properties. The thermal stability of the PAC resin will be examined through a test example.

II . Polyalkylene Carbonate  Method of producing resin

On the other hand, according to another embodiment of the invention,

Polymerizing monomers comprising epoxide and carbon dioxide in the presence of an organozinc catalyst,

Wherein the epoxide is an alkylene oxide having 2 to 20 carbon atoms which is substituted or unsubstituted with a halogen or an alkyl group having 1 to 5 carbon atoms and a cycloalkylene group having 4 to 20 carbon atoms which is unsubstituted or substituted with a halogen or an alkyl group having 1 to 5 carbon atoms Oxide in a molar ratio of 1: 0.01 to 1: 0.2.

Basically, monomers including epoxide and carbon dioxide are used for the production of the PAC resin. In particular, according to one embodiment of the invention, a mixture of an alkylene oxide and a cycloalkylene oxide is used as an epoxide in the monomer.

Specifically, the epoxide is a cyclic alkyl group having 2 to 20 carbon atoms, which is substituted or unsubstituted with halogen or an alkyl group having 1 to 5 carbon atoms, and a cycloalkyl group having 4 to 20 carbon atoms which is unsubstituted or substituted with halogen or an alkyl group having 1 to 5 carbon atoms Alkylene oxide.

Preferably, the alkylene oxide is selected from the group consisting of ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, isobutylene oxide, 1-pentene oxide, 2-pentene oxide, 1-hexene oxide, At least one compound selected from the group consisting of 1-decene oxide, 1-dodecene oxide, 1-tetradecene oxide, 1-hexadecene oxide, and 1-octadecene oxide.

And, the cycloalkylene oxide may be at least one compound selected from the group consisting of cyclopentene oxide, cyclohexene oxide, cyclooctene oxide, cyclododecene oxide, alpha-pinene oxide, and 2,3-epoxy norbornene have.

In particular, according to an embodiment of the invention, the epoxide may be prepared by reacting an alkylene oxide with a cycloalkylene oxide in a molar ratio of 1: 0.01 to 1: 0.2, or 1: 0.01 to 1: 0.15, or 1: 0.01 to 1: . That is, in order to sufficiently exhibit the effect of the mixed use of the cycloalkylene oxide, the epoxide preferably contains the cycloalkylene oxide in a molar ratio of 1: 0.01 to the alkylene oxide. However, when the cycloalkylene oxide is added in an excess amount, the interaction between the alkylene oxide and the cycloalkylene oxide may not occur properly, resulting in a decrease in the polymerization activity and an increase in the amount of byproducts generated. In this case, the polymerization time may be increased so that the time required for the interaction between the alkylene oxide and the cycloalkylene oxide can be somewhat secured. However, if the polymerization time is increased under the above conditions, the production amount of the byproduct is further increased, so that the economical efficiency can be lowered when the scale up of the production process is applied. Therefore, it is preferable that the epoxide contains a cycloalkylene oxide in a molar ratio of 1: 0.2 based on the alkylene oxide.

According to an embodiment of the present invention, the pressure of the carbon dioxide during the polymerization of the epoxide and the carbon dioxide is not particularly limited, but may be 1 to 200 bar, or 1 to 150 bar, or 1 to 100 bar, Or in the range of 1 to 50 bar.

On the other hand, polymerization of monomers including epoxide and carbon dioxide is carried out in the presence of an organozinc catalyst. The organic zinc catalyst is a catalyst obtained by reacting a zinc precursor with an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid, and can exhibit a high polymerization activity in a copolymerization reaction of obtaining a PAC resin from carbon dioxide and epoxide.

The zinc precursor is not particularly limited and examples thereof include zinc oxide, zinc sulfate (ZnSO ₄ ), zinc chlorate (Zn (ClO ₃ ) ₂ ), zinc nitrate (Zn (NO ₃ ) ₂ ) (Zn (OAc) ₂ ), zinc hydroxide, and the like can be used. Of these, zinc oxide and zinc hydroxide may preferably be used in that an organic zinc catalyst exhibiting high activity can be obtained. Each of these zinc precursors may be used alone or in combination of two or more.

The dicarboxylic acid used in the synthesis of the organic zinc catalyst may include an aliphatic dicarboxylic acid having 3 to 20 carbon atoms and an aromatic dicarboxylic acid having 6 to 40 carbon atoms. Specific examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as malonic acid, glutaric acid, succinic acid, and adipic acid; Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, homophthalic acid, and phenylglutaric acid. Of these, glutaric acid can be preferably used in that an organic zinc catalyst exhibiting high activity is obtained. These dicarboxylic acids may be used alone or in combination of two or more.

The dicarboxylic acid may be used in the same or an excessive molar amount as the zinc precursor. Specifically, the dicarboxylic acid may be used in a proportion of about 1 to 1.5 moles, or about 1.1 to 1.3 moles per mole of the zinc precursor. When the dicarboxylic acid is maintained in an equimolar or excess state with the zinc precursor, the reaction may proceed slowly in the form of an excessive amount of the dicarboxylic acid molecule or ions surrounding the zinc precursor dispersed uniformly. As a result, the zinc precursor can react with the dicarboxylic acid while hardly aggregating with each other, so that an organic zinc catalyst having a more uniform and fine particle size and exhibiting improved activity can be formed.

The reaction for obtaining the organozinc catalyst may proceed in a liquid medium in which a reactant comprising a zinc precursor and a dicarboxylic acid is present (e.g., proceeding in the form of a solution or dispersion in which the reactant is dissolved or dispersed) . The solvent usable here is not particularly limited, but aromatic hydrocarbon solvents such as benzene, toluene and xylene; Ether-based solvents such as diethyl ether, tetrahydrofuran and dioxane; Carbonate-based solvents such as dimethyl carbonate, diethyl carbonate and propyl carbonate; Acetonitrile, dimethylformamide, dimethylsulfoxide, hexamethylphosphoramide, and the like. Among them, aromatic hydrocarbon solvents such as benzene, toluene and xylene can be preferably used in that reaction solvents can be easily reused.

The amount of the solvent used in the reaction for obtaining the organic zinc catalyst is not particularly limited but may be adjusted to 300 to 10000 parts by weight based on 100 parts by weight of the zinc precursor so that the catalyst synthesis reaction can be performed smoothly .

Also, the catalyst synthesis reaction may be carried out at 20 to 150 ° C in consideration of the reaction efficiency. In this case, the reaction time may vary depending on the reaction temperature, and the reaction time may be generally adjusted to 1 to 10 hours.

On the other hand, according to the embodiment of the present invention, the production of the PAC resin can be carried out by solution polymerization in an organic solvent in which an organic zinc catalyst is dispersed. As a result, the heat of reaction can be appropriately controlled and the molecular weight or viscosity of the PAC resin to be obtained can be easily controlled.

In this solution polymerization, the organic solvent may be an organic solvent such as methylene chloride, ethylene dichloride, trichloroethane, tetrachloroethane, chloroform, acetonitrile, propionitrile, dimethylformamide, N- Methyl acetate, vinyl acetate, ethyl acetate, ethyl acetate, ethyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, One or more compounds selected from the group consisting of acetate, propyl acetate, butylolactone, caprolactone, nitropropane, benzene, styrene, xylene, and methyl propasol may be used. Of these, methylene chloride and ethylene dichloride can be preferably used in that polymerization reaction can be more effectively proceeded.

The organic solvent may be used in an amount of 50 to 10000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts by weight of the epoxide. That is, the organic solvent is preferably used in an amount of 50 parts by weight or more based on 100 parts by weight of the epoxide. However, when an organic solvent is used in an excessive amount, the concentration of the epoxide may be lowered, resulting in a decrease in productivity, and the molecular weight of the resin formed may be lowered or the side reaction may increase. Therefore, the organic solvent is preferably used in an amount of 10000 parts by weight or less based on 100 parts by weight of the epoxide.

The organic zinc catalyst may be used in an amount of 0.001 to 100 parts by weight, preferably 0.01 to 50 parts by weight, based on 100 parts by weight of the epoxide. That is, it is preferable that the organic zinc catalyst is present in an amount of 0.001 part by weight or more based on 100 parts by weight of the epoxide. However, when the catalyst is present in excess, by-products may be formed or back-biting of the polymer may occur. Therefore, the organic zinc catalyst is preferably present in an amount of 100 parts by weight or less based on 100 parts by weight of the epoxy compound.

And, the above-mentioned polymerization reaction can be carried out at a temperature of 20 to 100 캜. If the reaction temperature is lower than 20 ° C, there is a fear that a long time is required for the reaction, which may increase the side reaction. If the reaction temperature exceeds 100 ° C, the yield may be lowered due to an increase in the side reaction. In this case, the reaction time may vary depending on the reaction temperature, and the reaction temperature may be generally adjusted to 1 to 40 hours. Particularly, according to the embodiment of the present invention, since the alkylene oxide and the cycloalkylene oxide are used in a specific content ratio in the above-mentioned polymerization reaction, the activity of the catalyst can be maintained longer than that of the alkylene oxide and the cycloalkylene oxide, Can be delayed. Accordingly, even if the polymerization time is kept relatively long, the production of by-products (for example, ethylene carbonate and the like) can be suppressed.

The method of mixing the organic zinc catalyst, the epoxide and the carbon dioxide in the polymerization reaction is not particularly limited, but a method of mixing the organozinc catalyst with the epoxide and then adding carbon dioxide may be preferable in terms of ease of mixing .

The PAC resin obtained by the above-mentioned method can be provided as a final resin after removing the catalyst etc. by filtration or washing and drying.

According to the present invention, a PAC resin exhibiting biodegradability and having a high molecular weight and improved thermal stability is provided.

1 is an NMR spectrum of a polyalkylene carbonate resin according to an embodiment of the present invention.
2 is a GPC analysis graph of a polyalkylene carbonate resin according to an embodiment of the present invention.

 BRIEF DESCRIPTION OF THE DRAWINGS Fig. However, the following embodiments are intended to illustrate the invention, but the invention is not limited thereto.

Synthetic example

(Preparation of organic zinc catalyst)

7.93 g (0.06 mol) of glutaric acid was added to 100 ml toluene in a 250 ml round-bottomed flask and dispersed under reflux and heated at 55 ° C for 30 minutes. Separately, 4.1 g (0.05 mol) of ZnO was added to 50 ml of toluene and stirred to prepare a ZnO solution. 25% of the ZnO solution was first added to the glutaric acid solution to conduct the reaction. 25% of the remaining 75% was added after 1 hour to conduct the reaction. The next 25% was further added for 1 hour after the reaction was completed . Thereafter, after an elapse of 1 hour, the last 25% was added to proceed the reaction. The mixed solution was heated at 110 DEG C for 2 hours. After a white solid was formed, it was filtered, washed with acetone / ethanol and dried in a vacuum oven at 130 ° C to produce an organozinc catalyst.

Example  One

In the glove box, 0.4 g of organozinc catalyst and 8.52 g of dichloromethane were placed in a high-pressure reactor and then 8.9 g of epoxide (ethylene oxide: cyclohexene oxide = 1: 0.01 mol) was added. Then, carbon dioxide was introduced into the reactor and the pressure was increased to 30 bar. The polymerization reaction was carried out at 70 DEG C for 3 hours.

After completion of the reaction, the unreacted carbon dioxide and epoxide were removed together with the solvent dichloromethane. In order to determine the amount of the polyethylene carbonate resin produced, the remaining solid was completely dried and quantified. The activity and the yield of the catalyst according to the polymerization results are shown in Table 1 below.

Example  2

A polyethylene carbonate resin was prepared in the same manner as in Example 1 except that an epoxide mixed with ethylene oxide: cyclohexene oxide = 1: 0.05 mol was used.

Example  3

A polyethylene carbonate resin was prepared in the same manner as in Example 1 except that an epoxide mixed with ethylene oxide: cyclohexene oxide = 1: 0.2 mole was used.

Example  4

A polyethylene carbonate resin was prepared in the same manner as in Example 1 except that the polymerization reaction was conducted at 70 캜 for 6 hours.

Example  5

A polyethylene carbonate resin was prepared in the same manner as in Example 2 except that the polymerization reaction was conducted at 70 캜 for 6 hours.

Example  6

A polyethylene carbonate resin was prepared in the same manner as in Example 3 except that the polymerization reaction was conducted at 70 캜 for 6 hours.

Comparative Example  One

A polyethylene carbonate resin was prepared in the same manner as in Example 1 except that only ethylene oxide was used as the epoxide. The catalyst activity and yield according to the polymerization results are shown in Table 2 below.

Comparative Example  2

A polyethylene carbonate resin was prepared in the same manner as in Example 1, except that an epoxide mixed with ethylene oxide: styrene oxide = 1: 0.01 mol was used.

Comparative Example  3

A polyethylene carbonate resin was prepared in the same manner as in Example 1 except that an epoxide mixed with ethylene oxide: styrene oxide = 1: 0.05 mol was used.

Comparative Example  4

A polyethylene carbonate was prepared in the same manner as in Example 1 except that an epoxide mixed with ethylene oxide: cyclohexene oxide = 1: 0.25 mol was used.

Test Example  One

¹ H NMR spectrum (300 MHz, CDCl ₃ ) was observed for each of the polyethylene carbonate according to Examples and Comparative Examples, and the results are shown in Tables 1 and 2 below. Among them, NMR spectrum of the polyethylene carbonate of Example 1 is shown in Fig.

Yield
(g-PEC) Activity
of cat.
(gPEC / gCat.hr) NMR integral values (Crude) EC ^a PEC ^b PEC-PEG ^c PEG ^d PCHC ^e Example 1 4.24 21 1.6 100 6.96 2.3 1.52 Example 2 10.5 53 1.78 100 6.97 2.19 1.78 Example 3 8.70 47 1.75 100 6.18 2.02 2.02 Example 4 15.02 75 1.66 100 6.28 2.19 1.35 Example 5 14.91 79 1.5 100 3.51 0.12 1.57 Example 6 13.24 65 1.57 100 4.7 1.52 3.24

Yield
(g-PEC) Activity
of cat.
(gPEC / gCat.hr) NMR integral values (Crude) EC ^a PEC ^b PEC-PEG ^c PEG ^d PCHC ^e Comparative Example 1 13.48 51 3.65 100 4.69 0.77 - Comparative Example 2 5 25 3.05 100 1.9 1.99 - Comparative Example 3 8.55 46 3.17 100 2.62 - - Comparative Example 4 7.71 41 1.78 100 6.89 2.05 2.09

EC ^a : peak due to ethylene carbonate monomer

PEC ^b : peak due to polyethylene carbonate repeating unit

PEC-PEG ^c : (polyethylene carbonate) - (polyethylene glycol) copolymer peak by repeating unit

PEG ^d : polyethylene glycol peaks due to repeating units

PCHC ^e : polycyclohexene carbonate peak by repeating unit

The polymer of Comparative Example 2 and Comparative Example 3 in which ethylene oxide and styrene oxide were used as epoxides can be introduced with a structure capable of alleviating the decomposition mechanism of the polymer back-bone or terminal portion through the introduction of styrene oxide, This can reduce cyclic carbonate formation and degradation rate of polymer chain due to degradation of polymer chains.

On the other hand, the polymers of Examples in which ethylene oxide and cyclohexene oxide were used as epoxides were found to be more reduced in the alkoxide backbiting mechanism of the polymer through the introduction of cyclohexene oxide having a higher activation energy barrier than styrene oxide Is expected to be.

In addition, the production method according to the examples showed the same or higher polymer synthesis yield and catalytic activity as compared with the production method of the comparative examples, and the production amount of the by-product such as ethylene carbonate was remarkably low.

In Examples 4 and 5, although the polymerization reaction time was doubled as compared with Examples 1 and 2, the amounts of by-products were similar to each other, and the catalytic activity was high. From these results, it was confirmed that the activity of the catalyst can be maintained for a long time in the production method of the examples, and the polymerization rate is saturated, thereby delaying the point at which the conversion rate is no longer increased, and the production of by-products can be inhibited.

However, in the case of Comparative Example 4, the catalytic activity was lowered as the content ratio of the epoxide was out of the preferable range. As a result of NMR analysis for Comparative Example 4, the amount of ethylene carbonate (EC) produced in the by-product was relatively low but the content of other by-products such as polycyclohexene carbonate (PCHC) was high. This is presumably due to the excessive addition of cyclohexene oxide in the state where the interaction between ethylene oxide and cyclohexene oxide is not properly performed.

On the other hand, an NMR spectrum of the polyethylene carbonate resin of Example 1 shown in Fig. 1 was observed, and a CH ₂ peak due to the main repeating unit of polyethylene carbonate was confirmed at about 4.38 ppm. In addition, CH peaks due to the polymerization of the carbonate group and cyclohexene oxide at about 4.66 ppm could be found in the HMBC (correlation with ~ 154 ppm) pattern of HMBC (Heteronuclear multiple-bond correlation spectroscopy). And CH at about 3.09 ppm was due to the cyclohexene oxide present in the monomer (a COZY pattern similar to 4.66 ppm but no HMBC pattern with the carbonate). In addition, a small amount of peaks, which are presumed to be monomers, were found. As a result of the analysis of this NMR spectrum, the polyethylene carbonate resin according to Example 1 was found to have the repeating units of the above formula (1) or the repeating units of the above formula (3) in the main chain containing the repeating units formed by the combination of the above- Is expected to have a randomly distributed structure.

Test Example  2

1 g of the polyethylene carbonate resin according to Example 1 and Example 2 was dissolved in methylene chloride to prepare a polymer solution. Subsequently, the polymer solution was dropped into methanol containing 5% by weight of hydrochloric acid to obtain a modified polyethylene carbonate resin. Then, thermogravimetric analysis (TGA) was performed on the modified polyethylene carbonate resin at a rate of 10 ° C / min. The results are shown in Table 3 below.

99% 95% 90% 50% Residual Mn Mw PDI Example 1 119.33 194 198.33 215 0.32% 371000 910000 2.46 Example 2 189.79 206.5 211.333 223 0.60% 248000 710000 2.86

Referring to Table 3 above, it was confirmed that the polyethylene carbonate resin according to Example 1 had a very high molecular weight (Mw 910,000). It was confirmed that the polyethylene carbonate resin according to Example 3 had a lower molecular weight than the resin of Example 1, but had improved thermal stability.

Test Example  3

The polyethylene carbonate resin according to Example 5 was subjected to GPC analysis using CHCl ₃ , and the results are shown in Table 4 and FIG.

Mn Mw Mp PDI Example 5 248000 710000 699000 2.86

In FIG. 2, the portion other than the peak due to the polymer was detected after 18 minutes of the total analysis time of 24 minutes, and it was judged that a small amount of the component (for example, monomer component) having a very low molecular weight remained. Therefore, it is presumed that the resin of Example 5 has a structure in which an ethylene glycol bond is randomly contained in the main chain, and further, a portion originated from cyclohexene oxide is randomly bonded in the main chain.

Test Example  4

The polyethylene carbonate resins according to Example 2 and Comparative Example 1 were each processed into a thin film form. Each of the resin films was exposed to a high temperature in an oven at 120 DEG C to test the thermal decomposition tendency. The results are shown in Table 5 below.

lapse
time Content in polymer (% by weight) PEC-PEG ¹ EC ² PEG ³ PCHC ⁴ Example 2 0 95.27 0.60 0.07 4.06 One 95.19 0.44 0.04 4.33 2 94.88 0.62 0.04 4.46 3 95.65 0.40 0.06 3.98 Comparative Example 1 0 98.33 0.74 0.93 - 3 95.92 2.88 1.20 -

PEC-PEG ¹ : (polyethylene carbonate) - (polyethylene glycol) copolymer Content

EC ² : ethylene carbonate content

PEG ³ : polyethylene glycol content

PCHC ⁴ : polycyclohexene carbonate content

Referring to Table 5, it was confirmed that the resin of Example 2 exhibited excellent thermal stability due to less change in the content of ethylene carbonate in the polymer even when exposed to high temperature, compared with the resin of Comparative Example 1. [

Claims (7)

And each repeating unit represented by the following general formula (1), (2) and (3)
Wherein the repeating unit represented by the formula (3) is a polyalkylene carbonate resin having at least two repeating units represented by the formula (1) or at least two repeating units formed by combining the repeating units represented by the formula (1)
[Chemical Formula 1]

(2)

(3)

In the above Formulas 1 to 3,
R ¹ and R ² are each independently an alkylene having 1 to 20 carbon atoms which is substituted or unsubstituted with halogen or an alkyl having 1 to 5 carbon atoms,
A is cycloalkylene having 4 to 12 carbon atoms,
p is an integer of 2 to 10,
Each R ⁱ is independently hydrogen or alkyl of 1 to 5 carbon atoms, adjacent R ^{i s} may be connected to each other to form an aliphatic ring,
n is an integer from 10 to 5,000,
( n + 1 ): m is 1: 0.05 to 1: 3.
The method according to claim 1,
A polyalkylene carbonate resin exhibiting a ¹ H NMR (300 MHz, CDCl ₃ ) spectrum having at least one peak at delta of 4.50 to 4.70 ppm.
The method according to claim 1,
^{In the 1} H NMR spectrum, the integral value of the peak due to the repeating unit represented by the formula (2) is 1: 0.005 to 1: 5 relative to the integral value of the peak due to the repeating unit represented by the formula (1) , Polyalkylene carbonate resin.
The method according to claim 1,
And a weight average molecular weight (Mw) of 50,000 to 1,000,000.
The method according to claim 1,
Having a polydispersity index (PDI) of 2 to 6.
The method according to claim 1,
And a glass transition temperature (Tg) of 10 to 30 占 폚.
The method according to claim 1,
Polymerizing the monomers containing an alkylene oxide having 2 to 20 carbon atoms, a cycloalkylene oxide having 4 to 12 carbon atoms and carbon dioxide in the presence of an organic zinc catalyst at a temperature of 20 to 100 DEG C for 3 to 6 hours Wherein the polyalkylene carbonate resin is a polyalkylene carbonate resin.

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