Manufacturing method of polyethylene furandicarboxylate

Abstract

The invention provides a manufacturing method of polyethylene furandicarboxylate, comprising following steps. A biomass 2,5-furandicarboxylic acid and a biomass ethylene glycol are subjected to an esterification reaction, and a byproduct of the esterification reaction is water. Next, a polymerization reaction is carried out in the presence of a catalyst and a diethylene glycol inhibitor to prepare polyethylene furandicarboxylate. The diethylene glycol inhibitor includes sodium acetate, tetraethylammonium hydroxide or a combination thereof.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing polyethylene furanate, and more particularly to a method for manufacturing high-quality polyethylene furanate. [Previous Technology]

[0002] Polyethylene furan 2,5-dicarboxylate (PEF) is a biopolymer polyester with low emissions and good gas barrier properties, excellent thermal stability, high Tg point and good mechanical strength. It is mainly used in food and beverage packaging, films and flexible packaging and fibers.

[0003] There are two main methods for manufacturing PEF polyester. The first method uses bio-based dimethyl 2,5-furandicarboxylicacid (FDME) and bio-based ethylene glycol (EG) as raw materials, carrying out esterification and polymerization reactions to produce PEF, with methanol as a byproduct. The second method uses bio-based 2,5-furandicarboxylic acid (FDCA) and bio-based ethylene glycol (EG) as raw materials, carrying out esterification and polymerization reactions to produce PEF, with water as a byproduct.

[0004] In conventional PEF manufacturing methods using FDME and EG as raw materials (the first method mentioned above), compared to the second method, the produced PEF produces methanol as a byproduct. This byproduct is difficult to condense and collect during the process, resulting in relatively high equipment and energy consumption. Furthermore, FDME has a higher molecular weight than FDCA, leading to relatively lower production volume under the same equipment conditions. Therefore, from a raw material perspective, using FDCA is relatively advantageous. However, even though the second method produces PEF with water as a byproduct, which is relatively advantageous in terms of process, the resulting PEF has poor hue (brightness L < 65, yellowness b > 15) and excessively high diethylene glycol (DEG) content, affecting processability. Therefore, further improvements are needed.

[0005] Based on the above, developing a method for manufacturing high-quality polyethylene furanate to improve the hue of polyethylene furanate and reduce the content of diethylene glycol is an important topic in the industry. [Summary of the Invention]

[0006] The present invention provides a method for manufacturing polyethylene furanate to improve the hue of polyethylene furanate and reduce the content of diethylene glycol.

[0007] The method for manufacturing polyethylene furanate of the present invention includes the following steps: Biomass 2,5-furandicarboxylic acid is subjected to an esterification reaction with biomass ethylene glycol, the byproduct of which is water. Subsequently, a polymerization reaction is carried out in the presence of a catalyst and a diethylene glycol inhibitor to produce polyethylene furanate, the diethylene glycol inhibitor including sodium acetate, tetraethylammonium hydroxide, or a combination thereof.

[0008] In one embodiment of the present invention, the amount of diethylene glycol inhibitor added is 5 ppm to 100 ppm of the total amount of bio-ethylene glycol and bio-2,5-furandicarboxylic acid.

[0009] In one embodiment of the present invention, the amount of catalyst added is 200 ppm to 800 ppm of the total amount of bio-ethylene glycol and bio-2,5-furandicarboxylic acid.

[0010] In one embodiment of the present invention, the molar ratio of the esterification reaction between bio-ethylene glycol and bio-2,5-furandicarboxylic acid is 2.1 to 1.0.

[0011] In one embodiment of the present invention, the temperature of the esterification reaction is 170°C to 210°C.

[0012] In one embodiment of the present invention, the pressure of the esterification reaction is 1 bar to 1.5 bar.

[0013] In one embodiment of the present invention, the esterification reaction time is 1 hour to 6 hours.

[0014] In one embodiment of the present invention, the polymerization reaction temperature is 220°C to 280°C.

[0015] In one embodiment of the present invention, the polymerization reaction time is 1 hour to 7 hours.

[0016] In one embodiment of the present invention, the pressure of the polymerization reaction is 0.2 torr to 20 torr.

[0017] In one embodiment of the present invention, the diethylene glycol content of the prepared polyethylene furanate is less than 5 mol.

[0018] In one embodiment of the present invention, the hue L of the prepared polyethylene furanate is greater than 65% and b is less than 15.

[0019] In one embodiment of the present invention, the intrinsic viscosity (IV) of the prepared polyethylene furanate is greater than 0.60.

[0020] In one embodiment of the present invention, the Tg point of the prepared polyethylene furanate is greater than 82°C.

[0021] In one embodiment of the present invention, the catalyst includes an organometallic compound and an ionic liquid. The organometallic compound includes zinc acetate, organotitanium, organoantimony, or organoaluminum, and the ionic liquid includes 1-butyl-3-methylimidazolium hexafluoro-phosphate (BMI-PF6), 1-butyl-3-methylimidazolium tetrafluoro-borate (BMI-BF4), or a combination thereof.

[0022] Based on the above, the present invention provides a method for manufacturing polyethylene furanate, using biomass FDCA and biomass EG as raw materials to manufacture polyethylene furanate, and water is the byproduct. Therefore, the process is relatively advantageous in terms of production cost and environmental protection. In addition, the present invention uses a lower esterification temperature, resulting in better thermal history, and employs a low alcohol-to-acid ratio. Sodium acetate or tetraethylammonium hydroxide (TEAH) is added in the polymerization stage. As a result, the produced polyethylene furanate has the advantages of both good color and low DEG content.

Implementation Method

[0023] Hereinafter, embodiments of the present invention will be described in detail. However, these embodiments are illustrative, and the disclosure of the present invention is not limited thereto.

[0024] In this document, the range expressed as "from one value to another value" is a summary representation that avoids listing all the values ​​in the range in the specification. Therefore, the description of a particular value range covers any value within that range as well as the smaller value range defined by any value within that range, just as the arbitrary value and the smaller value range are described in the explanatory text of the specification.

[0025] This invention provides a method for manufacturing polyethylene furanate, comprising the following steps: An esterification reaction is carried out between bio-2,5-furandicarboxylic acid and bio-ethylene glycol, with water as a byproduct of the esterification reaction. Subsequently, a polymerization reaction is carried out in the presence of a catalyst and a diethylene glycol inhibitor to produce polyethylene furanate, wherein the diethylene glycol inhibitor includes sodium acetate, tetraethylammonium hydroxide, or a combination thereof.

[0026] In this embodiment, the molar ratio of bio-ethylene glycol to bio-2,5-furandicarboxylic acid in the esterification reaction is, for example, 2.1 to 1.0, preferably, 1.5 to 1.2. The esterification reaction temperature is, for example, 170°C to 210°C, preferably, 180°C to 200°C. The esterification reaction pressure is, for example, 1 bar to 1.5 bar. The esterification reaction time is, for example, 1 hour to 6 hours, preferably, 2 hours to 5 hours. The present invention mainly uses a lower esterification temperature, resulting in better thermal history, thereby achieving the purpose of energy saving and carbon reduction, and can suppress the formation of coloring substances and DEG.

[0027] In this embodiment, the catalyst may include an organometallic compound and an ionic liquid. The organometallic compound may include zinc acetate, organotitanium, organoantimony, or organoaluminum. The ionic liquid may include 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium tetrafluoroborate, or combinations thereof. The amount of catalyst added is, for example, 200 ppm to 800 ppm of the total amount of bio-ethylene glycol and bio-2,5-furandicarboxylic acid. The diethylene glycol inhibitor may include sodium acetate, tetraethylammonium hydroxide, or combinations thereof. The amount of diethylene glycol inhibitor added is, for example, 5 ppm to 100 ppm of the total amount of bio-ethylene glycol and bio-2,5-furandicarboxylic acid, preferably, 10 ppm to 50 ppm. By adding the diethylene glycol inhibitor, the formation of diethylene glycol can be suppressed under vacuum.

[0028] In this embodiment, the polymerization temperature is, for example, 220°C to 280°C, preferably, 230°C to 270°C. The polymerization time is, for example, 1 hour to 7 hours, preferably, 2 hours to 6 hours. The polymerization pressure is, for example, 0.2 torr to 20 torr, preferably, 0.5 torr to 10 torr.

[0029] In this embodiment, the prepared polyethylene furanate has a diethylene glycol content of less than 5 mol%, a hue L greater than 65%, a b less than 15, an intrinsic viscosity (IV) greater than 0.60, and a Tg point greater than 82°C.

[0030] Hereinafter, the method for manufacturing the poly(ethylene furanate) of the present invention will be described in detail by way of experimental examples. However, the following experimental examples are not intended to limit the present invention. Experimental Example 1

[0031] (1) Experimental equipment

[0032] A three-necked reaction flask with stirring function and a distillation column with 12 theoretical plates attached to the reaction flask.

[0033] (2) Esterification reaction

[0034] Take 148.8 g of biomass EG (2.4 mole) and 312.2 g of biomass FDCA (2 mole) and put them into a 3-necked reaction flask. The esterification reaction is carried out at 190°C for 3 hours. The pressure is maintained at 1 bar (atmospheric pressure). The top of the distillation column on the reaction flask is controlled at 100°C to separate the distilled gas (byproduct water and EG). The water can be discharged from the top of the column and further condensed. The EG is condensed at the top of the column and then refluxed back to the reaction flask to continue the esterification reaction. A total of 36 g of water is collected in the entire process.

[0035] (3) Polymerization reaction

[0036] 0.12 g (260 ppm) of antimony trioxide (Sb₂O₃) as a catalyst and 0.010 g (22 ppm) of sodium acetate as a DEG inhibitor were added to a 3-necked flask and stirred for 30 minutes. Then, a vacuum system was established, with a decompression rate of 5 torr min, and the pressure in the reaction vessel was reduced to 1 torr. The temperature was then increased from 190℃ to 265℃ and held at 265℃ for 4 hours to complete the polymerization reaction.

[0037] (4) PEF quality

[0038] The experimentally obtained PEF had the following characteristics: hue: L = 71.2%, b value = 12.8, DEG content 4.2 mol%, IV = 0.62, Tg = 84.2. Examples 2 to 6

[0039] The esterification temperature and the amount and amount of DEG inhibitor were varied, while the rest remained the same as in Example 1. The PEF quality, including L, b, DEG content, and IV, is listed in Table 1. Table 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 raw material EG(g) 148.8 161.2 186 FDCA(g) 312.2 312.2 312.2 Esterification conditions Temperature (°C) 190 187 184 180 195 200 stress (torr) 760 760 760 760 760 760 Time (hr) 3.0 3.0 3.0 3.0 3.0 3.0 Aggregation conditions catalyst name Antimony trioxide (Sb₂O₃) Weight (kg) 0.12 0.12 0.16 0.18 0.19 0.26 DEG inhibitors name Sodium acetate Sodium acetate Tetraethylammonium hydroxide Weight (kg) 0.010 0.012 0.015 0.018 0.010 0.021 Temperature (°C) 265 265 270 270 265 270 stress (torr) 1.0 1.1 1.0 1.3 1.1 1.2 Time (hr) 4.0 4.0 4.0 4.0 4.0 4.0 PEF quality L(%) 71.2 70.9 68.7 67.0 68.4 65.7 b 12.8 12.0 11.9 11.4 13.3 14.7 DEG (mol%) 4.2 3.8 3.6 3.5 3.9 4.8 IV 0.62 0.63 0.65 0.65 0.68 0.71

[0040] As can be seen from Table 1 above, Examples 1 to 6 use the manufacturing method of the present invention for poly(ethylene furanate) using bio-FDCA and bio-EG as raw materials to produce poly(ethylene furanate), and the byproduct is water. Therefore, the process is relatively advantageous in terms of production cost and environmental protection. In addition, a lower esterification temperature is used, resulting in better thermal history, thereby achieving the purpose of energy saving and carbon reduction. Furthermore, a low alkyd-acid ratio is used, and sodium acetate or tetraethylammonium hydroxide (TEAH) is added in the polymerization stage. In this way, the poly(ethylene furanate) produced also has the advantages of good color and low DEG content. Comparative Example 1

[0041] (1) Experimental equipment

[0042] A three-necked reaction flask with stirring function and a distillation column with 12 theoretical plates attached to the reaction flask.

[0043] (2) Esterification reaction

[0044] 148.8 g of biomass EG (2.4 mole) and 312.2 g of biomass FDCA (2 mole) were placed into a 3-necked reaction flask and esterified at 220°C for 2.5 hours. The pressure was maintained at 1.96 bar. The top of the distillation column on the reaction flask was controlled at 121°C to separate the distilled gas (byproduct water and EG). The water was used to keep the gas from being discharged from the top of the column and further condensed. The EG was condensed at the top of the column and then refluxed back into the reaction flask to continue the esterification reaction. A total of 36 g of water was collected during the entire process.

[0045] (3) Polymerization reaction

[0046] Take 0.12 g (260 ppm) of antimony trioxide (Sb2O3) as a catalyst, add it to a 3-necked flask and stir for 30 minutes. Then, establish a vacuum system, reduce the pressure at a rate of 5 torr min, reduce the pressure of the reaction vessel to 1 torr, and then raise the temperature from 190℃ to 265℃. Hold the temperature at 265℃ for 4 hours to complete the polymerization reaction.

[0047] (4) PEF quality

[0048] The PEF obtained in the experiment had the following characteristics: hue: L = 59.2%, b value = 21.8, DEG content: 6.4 mol%, IV = 0.61. Comparative Examples 2 to 6

[0049] The esterification and polymerization temperatures were changed, and the EG / FDCA molar ratio was also changed. All other parameters remained the same as in Comparative Example 1. PEF quality, including L, b, DEG content, and IV, is listed in Table 2. Table 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 raw material EG(g) 148.8 161.2 186 FDCA(g) 312.2 312.2 312.2 Esterification conditions Temperature (°C) 220 230 230 240 220 240 Pressure (bar) 1.96 2.43 2.43 3.15 1.96 3.15 Time (hr) 2.5 2.5 2.5 2.5 2.5 2.5 Aggregation conditions catalyst name Antimony trioxide (Sb₂O₃) Weight (kg) 0.12 0.12 0.16 0.18 0.19 0.26 DEG inhibitors none none none Temperature (°C) 265 265 270 270 265 270 stress (torr) 1.0 1.1 1.0 1.3 1.1 1.2 Time (hr) 4.0 4.0 4.0 4.0 4.0 4.0 PEF quality L(%) 59.2 60.7 59.9 61.2 63.8 63.0 b 21.8 22.4 22.7 23.1 21.4 23.4 DEG (mol%) 6.4 6.7 6.5 7.0 7.4 7.8 IV 0.61 0.63 0.61 0.62 0.62 0.64

[0050] As can be seen from Table 2 above, unlike the manufacturing method of poly(ethylene furanate) of the present invention, the esterification temperature of Comparative Examples 1 to 6 is higher and no diethylene glycol inhibitor is added. Therefore, the produced PEF has a poor color and a high DEG content, and does not have the advantages of energy saving and carbon reduction.

[0051] In summary, the present invention provides a method for manufacturing polyethylene furanate using biomass FDCA and biomass EG as raw materials, with water as a byproduct. Therefore, the process is relatively advantageous in terms of production cost and environmental protection, and has economic benefits. Furthermore, the present invention uses a lower esterification temperature, resulting in better thermal history and achieving energy saving and carbon reduction. It also employs a low alcohol-to-acid ratio and adds sodium acetate or tetraethylammonium hydroxide (TEAH) during the polymerization stage. As a result, the produced polyethylene furanate possesses both excellent color and low DEG content, thereby improving subsequent processability. [Simplified Explanation of the Diagram]

[0052] None.

Claims

1. A method for manufacturing polyethylene furanate, comprising: The method involves esterifying biomass 2,5-furandicarboxylic acid with biomass ethylene glycol, with water as a byproduct of the esterification reaction; and then performing a polymerization reaction in the presence of a catalyst and a diethylene glycol inhibitor to produce poly(ethylene furandicarboxylate), wherein the diethylene glycol inhibitor comprises sodium acetate, tetraethylammonium hydroxide, or a combination thereof, wherein the esterification reaction is carried out at a temperature of 170°C to 210°C, at a pressure of 1 bar to 1.5 bar, and for a duration of 1 hour to 6 hours, wherein the polymerization reaction is carried out at a temperature of 220°C to 280°C, for a duration of 1 hour to 7 hours, and at a pressure of 0.2 torr to 20 torr, wherein the catalyst comprises antimony trioxide.

2. The method for manufacturing polyethylene furanate as claimed in claim 1, wherein the amount of diethylene glycol inhibitor added is from 5 ppm to 100 ppm of the total amount of the bio-ethylene glycol and the bio-2,5-furandicarboxylic acid.

3. The method for manufacturing polyethylene furanate as claimed in claim 1, wherein the amount of catalyst added is 200 ppm to 800 ppm of the total amount of the bio-ethylene glycol and the bio-2,5-furandicarboxylic acid.

4. A method for manufacturing polyethylene furanate as claimed in claim 1, wherein the molar ratio of the bio-ethylene glycol to the bio-2,5-furandicarboxylic acid in the esterification reaction is 2.1 to 1.

0.

5. The method for manufacturing polyethylene furanate as described in claim 1, wherein the diethylene glycol content of the resulting polyethylene furanate is less than 5 mol.

6. A method for manufacturing polyethylene furanate as described in claim 1, wherein the resulting polyethylene furanate has a hue L greater than 65% and b less than 15.

7. A method for manufacturing polyethylene furanate as described in claim 1, wherein the polyethylene furanate produced has an intrinsic viscosity (IV) greater than 0.

60.

8. A method for manufacturing polyethylene furanate as described in claim 1, wherein the resulting polyethylene furanate has a Tg point greater than 82°C.