Method for preparing organic zinc catalyst, organic zinc catalyst prepared by the method and method for preparing polyalkylene carbonate resin using the catalyst

Abstract

The disclosed relates to a method for preparing an organic zinc catalyst used in the synthesis of a polyalkylene carbonate resin, an organic zinc catalyst provided therefrom, and a method for preparing a polyalkylene carbonate resin using the catalyst. The organic zinc catalyst according to the present disclosure includes a predetermined amount of Zr on the surface through a simple process, and thus can exhibit improved catalytic activity as compared to a conventional catalyst in the polymerization process for preparing a polyalkylene carbonate resin.

Claims

1. A method for preparing an organic zinc catalyst, comprising: reacting a zinc precursor with a dicarboxylic acid having 3 to 20 carbon atoms and a zirconium co-catalyst, wherein the zirconium co-catalyst is Zr-metal organic framework (MOF) containing zirconium, wherein the Zr-metal organic framework is at least one selected from the group consisting of UiO-66 (zirconium 1,4-dicarboxybenzene MOF), UiO-66-NH.sub.2, UiO-66-NH.sup.3+, UiO-67, UiO-68, and Nu-1000.

2. The method for preparing an organic zinc catalyst of claim 1, wherein the zirconium co-catalyst is used at a molar ratio of 0.1 mmol to 0.5 mol based on 1 mol of the zinc precursor.

3. The method for preparing an organic zinc catalyst of claim 1, wherein the zinc precursor includes at least one compound selected from the group consisting of zinc oxide (ZnO), zinc sulfate (ZnSO.sub.4), zinc chlorate (Zn(ClO.sub.3).sub.2), zinc nitrate (Zn(NO.sub.3).sub.2), zinc acetate (Zn(OAc).sub.2), and zinc hydroxide (Zn(OH).sub.2), and wherein the dicarboxylic acid having 3 to 20 carbon atoms includes at least one compound selected from the group consisting of a malonic acid, a glutaric acid, a succinic acid, an adipic acid, a terephthalic acid, an isophthalic acid, a homophthalic acid, and a phenylglutaric acid.

4. The method for preparing an organic zinc catalyst of claim 1, wherein the reaction is carried out in the presence of at least one solvent selected from the group consisting of toluene, hexane, dimethylformamide, ethanol, and water.

5. The method for preparing an organic zinc catalyst of claim 1, wherein the zirconium co-catalyst is used in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of the zinc precursor.

Description

BRIEF DESCRIPTION OF DRAWING

(1) The drawing shows the results of a Zr 3 d narrow scan spectrum (XPS) according to the change in the amount of zirconium co-catalyst added to ZnGA.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(2) Hereinafter, preferred embodiments are provided to help understanding of the present invention. However, these examples are given for illustrative purposes only, and the scope of the invention is not intended to be limited to or by these examples.

Example 1

(3) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid and 0.18 g of UiO-66 were added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(4) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Example 2

(5) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid and 0.36 g of UiO-66 were added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(6) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Example 3

(7) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid and 0.72 g of UiO-66 were added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(8) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Example 4

(9) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid and 0.04 g of UiO-66 were added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(10) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Example 5

(11) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid and 0.004 g of UiO-66 were added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(12) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Example 6

(13) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid and 0.36 g of ZrSO.sub.4 were added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(14) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Comparative Example 1

(15) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid was added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(16) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Comparative Example 2

(17) In a 100 ml round-bottom flask, 2.64 g (20 mmol) of glutaric acid and 0.1 of MgCl.sub.2 were added to 50 ml of toluene and dispersed under reflux, and then the mixture was heated at 55° C. for 30 minutes. 1.36 g of ZnO particles were added to the mixed solution and then stirred for 3 hours.

(18) The formed solids were separated using a centrifuge. The separated solids were washed three times with acetone/ethanol and then dried in a vacuum oven at 130° C. to obtain 3.2 g of a zinc glutarate-supported catalyst.

Comparative Example 3

(19) A zinc glutarate-supported catalyst was prepared in the same manner as in Example 1, except that cobalt oxide was used instead of UiO-66.

Test Example 1

(20) Polyethylene carbonates were prepared in the following manner using the catalysts of Examples 1 to 6 and Comparative Examples 1 to 3.

(21) In a glove box, 0.2 g of the catalyst and 8.5 g of dichloromethane were added to an autoclave reactor, and then 8.5 g of ethylene oxide was added thereto. Thereafter, the reactor was pressurized to 30 bar by injecting carbon dioxide. The polymerization reaction was carried out at 70° C. for 3 hours. After the completion of the reaction, unreacted carbon dioxide and ethylene oxide were removed together with dichloromethane used as a solvent. In order to determine the amount of polyethylene carbonate produced, the remaining solids were completely dried and quantified. The activity of the catalyst and the yield according to the polymerization results are shown in Table 1 below.

(22) TABLE-US-00001 TABLE 1 Activity of catalyst Catalyst (g-polymer/g-catalyst) Example 1 44 Example 2 45 Example 3 42 Example 4 42 Example 5 35 Example 6 29 Comparative Example 1 21 Comparative Example 2 0 Comparative Example 3 22

(23) Referring to Table 1, it was confirmed that the catalysts of Examples 1 to 6 exhibited excellent catalytic activity as compared with the catalysts of Comparative Examples 1 to 3, and the difference was significant.

(24) Meanwhile, when the ZnO precursor containing Co was used to prepare ZnGA as in Comparative Example 3, the activity of the catalyst was found to be 22 g/gcat, and when ZnO alone was used as in Comparative Example 1, the activity of the catalyst was found to be 21 g/gcat, thereby confirming that the polymerization yield of the polyalkylene carbonates was reduced as compared with the examples of the present invention.

Test Example 2

(25) During the preparation of the organic zinc catalysts, the ratio of the surface element component according to wt % of Zr added per the content of the co-catalyst (UiO-66) with respect to ZnGA was measured. The results are shown in Table 2 (atomic wt %). In addition, the results of a Zr 3 d narrow scan spectrum of each sample are shown in the drawing.

(26) TABLE-US-00002 TABLE 2 Sample (Amount of co- catalyst added) Zn O C Zr 1 ZnGA (0 wt %) 13.6 37.5 48.9 0 2 ZnGA (1 wt %) 14.9 36.8 48.1 0.2 3 ZnGA (5 wt %) 13.7 37.5 48.3 0.5 4 ZnGA (10 wt %) 12.8 37.6 48.7 0.7

(27) It can be seen from Table 2 and the drawing that the Zr components were well bonded to the surface of the zinc glutarate in the case of the organic zinc catalysts to which Zr was added in a predetermined amount.

(28) In contrast, when the amount of co-catalyst added was too small, the Zr components were not included on the surface of the organic zinc catalysts.