WO2020149670A1

WO2020149670A1 - Esterification reaction catalyst and method for preparing same

Info

Publication number: WO2020149670A1
Application number: PCT/KR2020/000812
Authority: WO
Inventors: 필리모노브이고르
Original assignee: 지에스칼텍스 주식회사
Priority date: 2019-01-16
Filing date: 2020-01-16
Publication date: 2020-07-23
Also published as: KR102178516B1; CN113301994A; KR20200089382A; CN113301994B

Abstract

An esterification reaction catalyst according to the present invention comprises a polystyrene-sulfonate-chitosan copolymer, and, thereby, has the effects of acquiring an ester-based compound at a high yield in a short period of time by improving the initial esterification reaction speed, and of having excellent long-term stability by having an improved mechanical strength.

Description

Esterification reaction catalyst and its manufacturing method

The present invention relates to an esterification reaction catalyst capable of improving the initial esterification reaction rate and having excellent mechanical strength for long-term use, and a method for manufacturing the same.

Esterification reaction refers to a reaction in which an acid and alcohol are reacted to produce an ester-based compound. The esterification reaction is a reversible reaction in which the synthesis and separation of an ester-based compound are simultaneously performed. Due to the nature of the reversible reaction, in order to synthesize an ester-based compound with a high yield in a short time, an esterification reaction catalyst having an excellent initial reaction rate with a reactant is required.

Amberlyst-based resin is usually used as the esterification reaction catalyst. However, the Amberlyst-based resin has a problem that the yield of the ester-based compound is lowered because the initial reaction rate with the reactant is not excellent.

In addition, the Amberlyst-based resin has a problem that long-term stability is reduced due to weak mechanical strength.

The present invention aims to provide a novel esterification reaction catalyst to solve the above problems.

It is also an object of the present invention to provide a method for preparing the novel esterification reaction catalyst.

However, the technical problem to be achieved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present invention, the esterification reaction catalyst according to the present invention includes a polystyrene sulfonate-chitosan copolymer.

In addition, according to another embodiment of the present invention, a method for preparing an esterification reaction catalyst according to the present invention comprises: (a) preparing a chitosan solution, (b) preparing a chitosan bead by alkali-treating the chitosan solution, (c) mixing the chitosan beads and a crosslinking agent to prepare crosslinked chitosan beads and (d) mixing the crosslinked chitosan beads and polystyrenesulfonate to produce a polystyrenesulfonate-chitosan copolymer.

The esterification reaction catalyst according to the present invention has an effect of obtaining an ester-based compound with a high yield in a short time by including a polystyrene sulfonate-chitosan copolymer. In addition, the esterification reaction catalyst according to the present invention includes a polystyrene sulfonate-chitosan copolymer, thereby improving mechanical strength and improving long-term stability.

The production method of the esterification reaction catalyst according to the present invention is a mixture of cross-linked chitosan beads and polystyrene sulfonate to prepare a polystyrene sulfonate-chitosan copolymer, thereby utilizing an eco-friendly, low-cost material to produce an ester-based compound with high yield in a short time. At the same time as obtained, the mechanical strength is improved, and an esterification reaction catalyst having excellent long-term stability can be prepared.

1 is a graph showing the conversion rate of ethyl lactate using the esterification reaction catalysts of Example 1 and Comparative Example 1,2 of the present invention.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the present embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims.

< Esterification Reaction catalyst>

The esterification reaction catalyst according to the present invention comprises a polystyrenesulfonate-chitosan copolymer.

Polystyrene sulfonate is a compound in which the hydrogen group of polystyrene is substituted with a sulfone group. Specifically, the chemical structure of the polystyrene sulfonate is as shown in Chemical Formula 1.

[Chemical structural formula 1]

Sulfone group (SO ₃ ^-) of the polystyrene sulfonate is an anionic type, sulfonic groups of polystyrene sulfonate in the anionic form (SO ₃ ^-) is combined with an amino group (NH ₂₎ of chitosan that will be described later polystyrene sulfonate-chitosan Copolymers can be formed.

Chitosan is a natural polymer material and is a compound bound by N-acetyl glucosamine. Specifically, the chemical structure of the chitosan is shown in Chemical Formula 2 below.

[Chemical structural formula 2]

The amino group (NH ₂ ) of the chitosan may be combined with the sulfone group (SO ₃ ⁻ ) of the polystyrene sulfonate to form a polystyrene sulfonate-chitosan copolymer.

The polystyrene sulfonate-chitosan copolymer may be a graft copolymer in which chitosan polymer is branched to a polystyrene sulfonate polymer main chain. The polystyrene sulfonate-chitosan copolymer exhibits the form of a graft copolymer, so that the chitosan may be located inside the polystyrene sulfonate-chitosan copolymer structure. In addition, the polystyrene sulfonate may be located outside the polystyrene sulfonate-chitosan copolymer structure. The chitosan is located inside the polystyrene sulfonate-chitosan copolymer structure, thereby improving the mechanical strength of the esterification reaction catalyst containing the polystyrene sulfonate-chitosan copolymer. The polystyrene sulfonate is located outside of the polystyrene sulfonate-chitosan copolymer structure, thereby improving the initial reaction rate with the reactants of the esterification reaction catalyst containing the polystyrene sulfonate-chitosan copolymer.

In the esterification reaction catalyst according to the present invention, the zirconia compound may be supported on a polystyrene sulfonate-chitosan copolymer.

The zirconia compound means a compound containing a transition metal, zirconium (Zr). The type of the zirconia compound containing the zirconium (Zr) used in the present invention is not particularly limited, for example, a zirconyl chloride (ZrOCl ₂ ) compound may be used.

The zirconia compound can be used as a carrier for the polystyrene sulfonate-chitosan copolymer. The zirconia compound is used as a carrier of the polystyrene sulfonate-chitosan copolymer, so that the esterification reaction catalyst in which the zirconia compound is supported on the polystyrene sulfonate-chitosan copolymer has an effect of further improving the initial reaction rate with the reactants. .

As described above, the esterification reaction catalyst containing the polystyrene sulfonate-chitosan copolymer improves an initial reaction rate with a reactant, and thus has an effect of obtaining an ester-based compound with a high yield in a short time. In addition, the esterification reaction catalyst containing the polystyrene sulfonate-chitosan copolymer has improved mechanical strength and thus has excellent long-term stability. In addition, the esterification reaction catalyst in which the zirconia compound is supported on the polystyrene sulfonate-chitosan copolymer further improves the initial reaction rate with the reactants, thereby obtaining an ester-based compound with a higher yield in a short time.

< Esterification Method of manufacturing reaction catalyst>

The method for preparing the esterification reaction catalyst according to the present invention includes (a) preparing a chitosan solution, (b) preparing a chitosan bead by alkali-treating the chitosan solution, and (c) mixing the chitosan beads and a crosslinking agent. Preparing a crosslinked chitosan bead and (d) mixing the crosslinked chitosan bead with polystyrenesulfonate to produce a polystyrenesulfonate-chitosan copolymer.

First, the manufacturing method according to the present invention includes the steps of (a) preparing a chitosan solution.

The chitosan solution may be prepared by mixing a chitosan flake with an acid solution. The acid solution used in preparing the chitosan solution is not particularly limited, and for example, acetic acid may be used. In addition, chitosan flakes used in preparing the chitosan solution are not particularly limited, and for example, chitosan flakes having a weight average molecular weight of 190,000 to 375,000 may be used.

Specifically, the chitosan solution is a step of preparing a mixture by dissolving chitosan flakes in acetic acid at a temperature of about 20 to 30°C, passing the mixture through a filter to remove undissolved chitosan flake particles, and then obtaining a chitosan solution. Can be produced by.

Next, the manufacturing method according to the present invention includes (b) preparing a chitosan bead by treating the chitosan solution with an alkali.

The chitosan beads may be prepared as chitosan beads after alkali treatment of the chitosan solution with an alkali solution. The pH of the chitosan solution treated with alkali by the alkali solution may be 8 to 9, indicating weak basicity. The alkali solution used in the preparation of chitosan beads is not particularly limited, and for example, sodium hydroxide (NaOH) aqueous solution may be used.

Specifically, the chitosan beads are prepared by mixing a chitosan solution and sodium hydroxide at a temperature of about 20 to 30° C., and stirring the chitosan solution and the sodium hydroxide for about 12 to 18 hours to obtain chitosan beads. Can.

Next, the manufacturing method according to the present invention includes the steps of (c) mixing the chitosan beads and a crosslinking agent to prepare crosslinked chitosan beads.

The method for preparing the crosslinked chitosan beads may include mixing the chitosan beads and a crosslinking agent, and washing the chitosan beads mixed with the crosslinking agent. The crosslinking agent used in preparing the crosslinked chitosan beads is not particularly limited, and for example, epichlorohydrin (C ₃ H ₅ OCl) may be used.

Specifically, the method for preparing the cross-linked chitosan beads comprises mixing the chitosan beads and the epichlorohydrin at a rotational speed of 100 to 300 rpm in a temperature range of 40 to 60°C, and the epichloro until the pH is about 7. It can be prepared by washing the chitosan beads mixed with hydrin to obtain cross-linked chitosan beads.

Next, the production method according to the present invention includes the step of preparing a polystyrene sulfonate-chitosan copolymer by mixing the crosslinked chitosan beads and polystyrene sulfonate (d).

The method for preparing the polystyrene sulfonate-chitosan copolymer may include mixing the cross-linked chitosan beads and the polystyrene sulfonate to prepare a mixture, and adding an acid to the mixture. In addition, the method of adding an acid to the mixture may be performed by adding the acid to the mixture at once or by adding the acid evenly to the mixture and adding it per unit time.

Specifically, the method for preparing the polystyrene sulfonate-chitosan copolymer is a mixture of the crosslinked chitosan beads and the polystyrene sulfonate for 12 to 18 hours at a rotational speed of 100 to 300 rpm in a temperature range of 20 to 60°C. Can be produced. Then, after adding hydrochloric acid (HCl) to the mixture at once, the mixture and the hydrochloric acid may be stirred at a rotational speed of 100 to 300 rpm in a temperature range of 10 to 50°C. After the mixture and the hydrochloric acid are stirred for 15 to 25 hours, a polystyrene sulfonate-chitosan copolymer may be prepared.

In addition, the method for preparing the polystyrene sulfonate-chitosan copolymer is prepared by mixing the cross-linked chitosan beads and the polystyrene sulfonate for 12 to 18 hours at a rotational speed of 100 to 300 rpm in a temperature range of 20 to 60°C. can do. Thereafter, hydrochloric acid evenly distributed in the mixture may be added about every hour. After the hydrochloric acid evenly distributed is added to the mixture, the mixture and the hydrochloric acid may be stirred at a rotational speed of 100 to 300 rpm in a temperature range of 10 to 50°C. After the mixture and the hydrochloric acid are stirred for 15 to 25 hours, a polystyrene sulfonate-chitosan copolymer may be prepared.

The method of adding an acid to the mixture can be performed by two processes as described above. The total amount of acid added to the mixture during the two processes may be the same. The esterification reaction catalyst prepared by the method of temporarily adding an acid to the mixture in the above two processes has further improved mechanical strength and thus has excellent long-term stability. The esterification reaction catalyst prepared by the method of uniformly distributing the acid to the mixture in the above two processes and adding per unit time further improves the initial reaction rate with the reactants, thereby obtaining an ester-based compound with a higher yield in a short time It has the effect.

In addition, the production method according to the present invention may further include a step of (e) supporting the zirconia compound on the polystyrene sulfonate-chitosan copolymer after step (d).

The step of supporting the zirconia compound on a polystyrene sulfonate-chitosan copolymer is a step of preparing a mixture by mixing a solution containing the polystyrene sulfonate-chitosan copolymer and a zirconia compound, and drying the mixture to polystyrene the zirconia compound It may include the step of loading on the sulfonate-chitosan copolymer.

Specifically, the step of supporting the zirconia compound on the polystyrene sulfonate-chitosan copolymer is a mixture of the polystyrene sulfonate-chitosan copolymer and the zirconyl chloride (ZrOCl ₂ ) compound for 30 minutes to 2 hours at a temperature of about 25°C. Preparing a mixture, and drying the mixture at a temperature range of 60 ~ 100 ℃ for 8 ~ 12 hours may include the step of loading the zirconia compound in a polystyrene sulfonate-chitosan copolymer.

The esterification reaction catalyst in which the zirconia compound is supported on the polystyrene sulfonate-chitosan copolymer further improves the initial reaction rate with the reactants, thereby obtaining an ester-based compound with a higher yield in a short time.

Hereinafter, preferred embodiments are provided to help understanding of the present invention. However, the following examples are only provided to more easily understand the present invention, and the contents of the present invention are not limited by the following examples.

< Example >

1) Preparation of chitosan solution: After adding 20 g of chitosan powder to 980 g of 1% aqueous acetic acid solution at room temperature, the mixture is stirred until the chitosan powder is completely dissolved. Then filter to remove solid impurities and obtain a clear solution.

2) Preparation of chitosan beads: While stirring 1.5 L of a 2M NaOH aqueous solution, 700 g of the chitosan solution obtained in step 1) was added at a rate of 10 mL/h at room temperature, followed by further stirring the solution containing the resulting chitosan beads for 15 hours. do. Chitosan beads are washed several times with ultrapure water to a pH of 8-9.

3) Crosslinking of chitosan beads: After adding the chitosan beads prepared in 2) to 1 L of a 0.38M NaOH aqueous solution, the mixture with 30 g of epihydrochlorin is stirred at 50° C. for 12 to 18 hours. The cross-linked chitosan beads are washed with ultrapure water to about pH 7.

4) grafting polystyrene sulfonate into chitosan beads: 70 g of 25% poly(sodium 4-styrenesulfonate) aqueous solution was added to 250 mL of ultrapure water containing the crosslinked chitosan beads prepared in the above 3) process and 12 at 40°C. After stirring for ~18 hours, 12.5 mL of 37% hydrochloric acid was added, followed by further stirring at room temperature for 20 hours. The obtained solid was washed three times with 1 L of a 0.1 M HCl ethanol/ultra pure water (1:1 weight ratio) solution and three times with 1 L of ethanol.

5) Zr loading: 500 g of the beads prepared in the above 4) process in 500 mL of ethanol were mixed with 500 ml of ethanol, and 100-500 g of zirconyl chloride (30 wt%) in hydrochloric acid was added to the solution, The mixture was stirred at room temperature for 1 hour, washed three times with 1 L of a 0.1 M HCl ethanol/ultra pure (1:1 weight ratio) solution and three times with 1 L of ethanol. The washed solid is dried to obtain a catalyst (Zr-PSS-CS).

6) Thermal decompression treatment: The catalyst prepared in step 5) is put in a vacuum oven and subjected to reduced pressure treatment at 140 to 300° C. for 2 hours to obtain a catalyst having excellent mechanical strength.

Amerlyst-15 (manufacturer: Rohm & Haas) was used as the esterification catalyst.

Amerlyst-39 (manufacturer: Rohm & Haas) was used as the esterification catalyst.

The mixture of 0.4 g of the catalysts of Example 1 and Comparative Examples 1,2 and 40 mL of ethanol is heated to 80°C while stirring. After adding 20 mL of lactic acid, the mixture was collected in 1 mL increments over time while stirring, and GC (Gas Chromatography) analysis was performed, and the results are shown in Table 1 and FIG. 1.

As shown in Table 1 and Figure 1, when using the esterification reaction catalyst of Example 1 compared to the case of using the esterification reaction catalyst of Comparative Example 1,2, the initial esterification reaction rate is improved and high yield in a short time It can be confirmed that ethyl lactate can be obtained.

Although the present invention has been described as described above, it is obvious that the present invention is not limited by the embodiments disclosed herein, and that various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. In addition, although the operation and effect according to the configuration of the present invention is not explicitly described while describing the embodiments of the present invention, it is natural that the predictable effect by the configuration should also be recognized.

Claims

Polystyrene sulfonate-comprising a chitosan copolymer

Esterification catalyst.
According to claim 1,

A zirconia compound is supported on the polystyrene sulfonate-chitosan copolymer.

Esterification catalyst.
The method according to claim 1 or 2,

The polystyrene sulfonate-chitosan copolymer

Characterized by being a graft copolymer

Esterification catalyst.
(a) preparing a chitosan solution;

(b) preparing chitosan beads by alkali-treating the chitosan solution;

(c) mixing the chitosan beads and a crosslinking agent to prepare crosslinked chitosan beads; And

(d) mixing the crosslinked chitosan beads and polystyrenesulfonate to prepare a polystyrenesulfonate-chitosan copolymer; Containing

Method for preparing esterification catalyst.
The method of claim 4,

After step (d),

(e) supporting a zirconia compound on the polystyrene sulfonate-chitosan copolymer; Characterized in that it further comprises

Method for preparing esterification catalyst.
The method of claim 4,

The chitosan solution of step (a) is

Characterized in that it is prepared by mixing a chitosan flake in an acid solution

Method for preparing esterification catalyst.
The method of claim 4,

The pH of the alkaline-treated chitosan solution in step (b) is 8-9.

Method for preparing esterification catalyst.
The method of claim 4,

The crosslinking agent of step (c) is characterized in that the epichlorohydrin (epichlorohydrin)

Method for preparing esterification catalyst.
The method of claim 4,

Step (c) is,

(c-1) mixing the chitosan beads and the crosslinking agent; And

(c-2) washing the chitosan beads mixed with the crosslinking agent; containing

Method for preparing esterification catalyst.
The method of claim 4,

Step (d) is,

(d-1) preparing a mixture by mixing the crosslinked chitosan beads and the polystyrene sulfonate; And

(d-2) adding an acid to the mixture; containing

Method of preparing an esterification reaction catalyst.
The method of claim 10,

The method of adding an acid to the mixture in step (d-2)

Characterized in that the method of adding the acid to the mixture at a time

Method for preparing esterification catalyst.
The method of claim 10,

The method of adding an acid to the mixture in step (d-2) is

The method is characterized in that the acid is evenly distributed to the mixture and added per unit time.

Method of preparing an esterification reaction catalyst.