Method for efficiently removing foreign ions in hexafluoropropylene polymer

Abstract

The invention relates to a method for efficiently removing foreign ions in a hexafluoropropylene polymer. The crude hexafluoropropylene polymer is fed into the upper part of the filter, most impurities are filtered, and the material is discharged from the lower part of the filter; the filtered hexafluoropropylene polymer is adsorbed by an adsorption tower, impurities are further removed, and the high-purity hexafluoropropylene polymer is obtained; the modified high-temperature clay disclosed by the invention is prepared by carrying out a click chemical reaction of sulfydryl-olefin on high-temperature clay powder, nickel acetate, ethanol, magnesium thioglycolate, 3-vinyl quinoline and 2-hydroxy-2-methyl-1-phenyl-1-acetone under the irradiation of ultraviolet light. The hexafluoropropylene polymer prepared by the preparation method disclosed by the invention has relatively high purity.

Description

Technical Field

[0001] The present invention relates to the technical field of hexafluoropropylene polymers, and in particular to an efficient method for removing impurity ions in hexafluoropropylene polymers. Background Art

[0002] Hexafluoropropylene polymer is a polymer copolymerized from hexafluoropropylene and other monomers. Hexafluoropropylene is a colorless gas at normal temperature and pressure, slightly soluble in ethanol and ether. It is one of the basic raw materials in the organic fluorine industry, mainly used in the production of various fluorine-containing fine chemical products, pharmaceutical intermediates, fire extinguishing agents, etc.

[0003] Chinese Patent CN115368207A: Belonging to the technical field of organic fluorine chemistry, it specifically relates to a purification method for hexafluoropropylene dimer. The purification method for hexafluoropropylene dimer includes the following steps: (1) Mix the crude hexafluoropropylene dimer with a nucleophile and an aprotic polar solvent, and control the temperature for reaction; (2) Let the mixture after the reaction stand for liquid separation, remove the upper layer liquid, and wash the lower layer liquid to obtain perfluoro-4-methyl-2-pentene.

[0004] Chinese Patent CN116020152B: Disclosed is a system and method for continuously separating hexafluoropropylene dimer and hexafluoropropylene trimer, belonging to the technical field of chemical production. The system includes five series-connected rectification towers. The bottom of the previous rectification tower is connected to the middle of the next rectification tower. The top of each rectification tower outputs the corresponding component, and the bottom of the fifth rectification tower outputs the heavy components. The present invention uses a continuous rectification method. Utilizing the differences in the boiling points of light components, hexafluoropropylene dimer, transitional fractions, hexafluoropropylene trimer, and heavy components, the reaction crude product continuously flows and is rectified and separated in the rectification towers with gradually increasing top temperature and bottom temperature from front to back. The hexafluoropropylene dimer is taken out from the top of the second rectification tower, and the hexafluoropropylene trimer is taken out from the top of the fourth rectification tower.

[0005] Chinese Patent CN118619810A: Belonging to the technical field of fluorochemical industry, it specifically relates to hexafluoropropylene trimer and its preparation method. The preparation method for hexafluoropropylene trimer of the present invention includes the following steps: Add an aprotic solvent, catalyst a, and catalyst b into a closed container, heat up and introduce hexafluoropropylene, maintain the reaction temperature and pressure, and carry out an addition reaction. The obtained reaction solution is washed and rectified to obtain hexafluoropropylene trimer; The catalyst a is one of potassium bifluoride, sodium bifluoride, and cesium bifluoride; The catalyst b is one of triethylamine, N-methylcyclohexylamine, and N-methyldiethanolamine.

[0006] For the above patents and the existing technologies, the techniques for purifying hexafluoropropylene polymers and removing impurities are complex, costly, and the impurity removal effect is not obvious. The purity of hexafluoropropylene polymers still needs to be further improved. Summary of the Invention

[0007] To solve the above problems, the present invention provides an efficient method for removing impurity ions in hexafluoropropylene polymer, and its operation steps are as follows:

[0008] S1: Feed the crude hexafluoropropylene polymer into the upper part of the filter, filter out most of the impurities, and discharge from the lower part of the filter;

[0009] S2: The filtered hexafluoropropylene polymer is further adsorbed by an adsorption tower to remove impurities, and a high-purity hexafluoropropylene polymer is obtained.

[0010] A filter layer is laid in the filter, and the filter layer is a layered activated carbon fiber felt.

[0011] An electrolysis layer is provided in the filter, and the electrolysis electrode is an iron electrode.

[0012] An adsorbent is installed in the adsorption tower, and the preparation method of the adsorbent is as follows:

[0013] By weight, 70 - 90 parts of modified alumina, 10 - 20 parts of modified high-temperature clay, 1 - 3 parts of magnesium oxide, and 1 - 3 parts of silica gel are stirred and mixed evenly to obtain the adsorbent.

[0014] The preparation method of the modified alumina is as follows:

[0015] By weight, 50 - 60 parts of alumina powder, 5 - 15 parts of nickel acetate, and 100 - 150 parts of ethanol are stirred and mixed, and then heated to 650 - 750 °C in a nitrogen atmosphere, calcined at high temperature for 7 - 12 h, and then cooled to room temperature to obtain modified alumina.

[0016] The preparation method of the modified high-temperature clay is as follows:

[0017] By weight, 30 - 40 parts of high-temperature clay powder, 0.5 - 5 parts of nickel acetate, and 80 - 100 parts of ethanol are stirred and mixed, and then heated to 100 - 120 °C in a nitrogen atmosphere and reacted for 2 - 5 h; after cooling to room temperature, 0.1 - 1 part of magnesium mercaptoacetate, 0.1 - 1 part of 3-vinylquinoline, and 0.01 - 0.1 part of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone are added, and under ultraviolet light irradiation, a thiol-ene click chemical reaction is carried out; the light intensity is 5 - 10 mW / cm 2 , the reaction temperature is 20 - 30 °C, and the reaction time is 1 - 3 h; after the reaction, it is continuously cooled to room temperature in a nitrogen atmosphere to obtain modified high-temperature clay.

[0018] Reaction Mechanism

[0019] Unique synergy of filtration and electrolysis: The filter combines a layered activated carbon fiber felt filtration layer and an iron electrode electrolysis layer. It can not only remove larger particulate impurities through the physical adsorption and interception of the activated carbon fiber felt, but also utilize the electrolysis of the iron electrode to convert some ionic impurities into filterable or adsorbable substances through electrochemical redox reactions, improving the impurity removal efficiency.

[0020] Design and preparation of high-performance adsorbents: The adsorbent is a combination of modified alumina, modified high-temperature clay, magnesium oxide, and silica gel. These components work synergistically, having a high adsorption capacity and good selectivity. Among them, the modified alumina forms a unique crystal structure and surface active sites through doping with nickel acetate and high-temperature calcination, enhancing the adsorption ability for impurity ions; the modified high-temperature clay introduces specific functional groups through thiol-ene click chemical reactions, further improving the adsorption selectivity for certain specific impurity ions.

[0021] Application of thiol-ene click chemical reactions: In the preparation process of modified high-temperature clay, thiol-ene click chemical reactions are innovatively used. This reaction has the advantages of mild reaction conditions, high selectivity, and fast reaction rate, and can accurately introduce specific functional groups on the surface of high-temperature clay, thereby improving the adsorption performance and selectivity of modified high-temperature clay for impurity ions, and also improving the efficiency and controllability of the entire preparation process.

[0022] Technical effects

[0023] An efficient method for removing impurity ions in hexafluoropropylene polymers according to the present invention has the following remarkable effects compared with the prior art:

[0024] 1. Efficient removal of impurity ions: Through the removal method of the present invention, various impurity ions in hexafluoropropylene polymers can be effectively removed, significantly improving the purity and quality of the polymers.

[0025] 2. Economical and environmentally friendly: The raw materials and processes used in the present invention are relatively simple and have low costs; at the same time, nitrogen protection is adopted during the preparation process, reducing environmental pollution and conforming to the development concept of green chemistry.

[0026] 3. The adsorbent is renewable: The adsorbent prepared by the present invention has good regeneration performance. After simple regeneration treatment, the adsorbent can be reused, reducing production costs. Specific embodiments

[0027] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in combination with examples and comparative examples:

[0028] Testing the purity of hexafluoropropylene polymers: Determined by gas chromatography.

[0029] Example 1

[0030] A method for efficiently removing impurity ions in hexafluoropropylene polymer, and its operation steps are as follows:

[0031] S1: Feed the crude hexafluoropropylene polymer into the upper part of the filter, filter out most of the impurities, and discharge from the lower part of the filter;

[0032] S2: The filtered hexafluoropropylene polymer is further adsorbed by an adsorption tower to remove impurities, and a high-purity hexafluoropropylene polymer is obtained.

[0033] A filter layer is laid in the filter, and the filter layer is a layered activated carbon fiber felt.

[0034] An electrolysis layer is provided in the filter, and the electrolysis electrode is an iron electrode.

[0035] An adsorbent is installed in the adsorption tower, and the preparation method of the adsorbent is as follows:

[0036] Mix 70 g of modified alumina, 10 g of modified high-temperature clay, 1 g of magnesium oxide, and 1 g of silica gel evenly by stirring to obtain the adsorbent.

[0037] The preparation method of the modified alumina is as follows:

[0038] Mix 50 g of alumina powder, 5 g of nickel acetate, and 100 g of ethanol by stirring, and then, under the atmosphere of nitrogen, heat up to 650 °C, calcine at high temperature for 7 h, and then cool to room temperature to obtain the modified alumina.

[0039] The preparation method of the modified high-temperature clay is as follows:

[0040] Mix 30 g of high-temperature clay powder, 0.5 g of nickel acetate CAS: 373-02-4, and 80 g of ethanol by stirring, and then, under the atmosphere of nitrogen, heat up to 100 °C and react for 2 h; after cooling to room temperature, add 0.1 g of magnesium mercaptoacetate CAS: 63592-16-5, 0.1 g of 3-vinylquinoline CAS: 67752-31–2, and 0.01 g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone CAS: 7473-98-5, and carry out a thiol-ene click chemical reaction under ultraviolet light irradiation; the light intensity is 5 mW / cm 2 , the reaction temperature is 20 °C, and the reaction time is 1 h; after the reaction is completed, continue to cool to room temperature under the nitrogen atmosphere to obtain the modified high-temperature clay.

[0041] Example 2

[0042] A method for efficiently removing impurity ions in hexafluoropropylene polymer, and its operation steps are as follows:

[0043] S1: Feed the crude hexafluoropropylene polymer into the upper part of the filter to filter out most of the impurities, and discharge from the lower part of the filter.

[0044] S2: The filtered hexafluoropropylene polymer is further adsorbed by the adsorption tower to remove impurities further, and a high-purity hexafluoropropylene polymer is obtained.

[0045] A filter layer is laid in the filter, and the filter layer is a layered activated carbon fiber felt.

[0046] An electrolysis layer is provided in the filter, and the electrolysis electrode is an iron electrode.

[0047] An adsorbent is installed in the adsorption tower, and the preparation method of the adsorbent is as follows:

[0048] Mix 75 g of modified alumina, 13 g of modified high-temperature clay, 2 g of magnesium oxide, and 2 g of silica gel evenly by stirring to obtain the adsorbent.

[0049] The preparation method of the modified alumina is as follows:

[0050] Mix 53 g of alumina powder, 8 g of nickel acetate, and 110 g of ethanol evenly by stirring, and then heat to 680 °C under the atmosphere of nitrogen, calcine at high temperature for 9 h, and then cool to room temperature to obtain the modified alumina.

[0051] The preparation method of the modified high-temperature clay is as follows:

[0052] Mix 33 g of high-temperature clay powder, 2 g of nickel acetate CAS: 373-02-4, and 85 g of ethanol evenly by stirring, and then heat to 105 °C under the atmosphere of nitrogen and react for 3 h; after cooling to room temperature, add 0.5 g of magnesium mercaptoacetate CAS: 63592-16-5, 0.5 g of 3-vinylquinoline CAS: 67752-31–2, and 0.05 g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone CAS: 7473-98-5, and carry out the thiol-ene click chemical reaction under ultraviolet light irradiation; the light intensity is 6 mW / cm 2 , the reaction temperature is 25 °C, and the reaction time is 2 h; after the reaction is completed, continue to cool to room temperature under the nitrogen atmosphere to obtain the modified high-temperature clay.

[0053] Example 3

[0054] An efficient method for removing impurity ions in hexafluoropropylene polymer, and its operation steps are as follows:

[0055] S1: Feed the crude hexafluoropropylene polymer into the upper part of the filter to filter out most of the impurities, and discharge from the lower part of the filter.

[0056] S2: The filtered hexafluoropropylene polymer is further adsorbed in an adsorption tower to remove impurities and obtain high-purity hexafluoropropylene polymer.

[0057] A filter layer is laid in the filter, and the filter layer is a layered activated carbon fiber felt.

[0058] An electrolysis layer is provided in the filter, and the electrolysis electrode is an iron electrode.

[0059] An adsorbent is installed in the adsorption tower. The preparation method of the adsorbent is as follows:

[0060] 85 g of modified alumina, 18 g of modified high-temperature clay, 2 g of magnesium oxide, and 2 g of silica gel are stirred and mixed evenly to obtain the adsorbent.

[0061] The preparation method of the modified alumina is as follows:

[0062] 58 g of alumina powder, 13 g of nickel acetate, and 140 g of ethanol are stirred and mixed. Then, in a nitrogen atmosphere, the temperature is raised to 730 °C, and after high-temperature roasting for 11 h, it is cooled to room temperature to obtain modified alumina.

[0063] The preparation method of the modified high-temperature clay is as follows:

[0064] 38 g of high-temperature clay powder, 4 g of nickel acetate CAS: 373-02-4, and 95 g of ethanol are stirred and mixed. Then, in a nitrogen atmosphere, the temperature is raised to 115 °C and reacted for 4 h; after cooling to room temperature, 0.8 g of magnesium mercaptoacetate CAS: 63592-16-5, 0.8 g of 3-vinylquinoline CAS: 67752-31–2, and 0.08 g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone CAS: 7473-98-5 are added, and under ultraviolet light irradiation, a thiol-ene click chemical reaction is carried out; the light intensity is 8 mW / cm 2 , the reaction temperature is 25 °C, and the reaction time is 2 h; after the reaction, it is continuously cooled to room temperature in a nitrogen atmosphere to obtain modified high-temperature clay.

[0065] Example 4

[0066] An efficient method for removing impurity ions in hexafluoropropylene polymer, and its operation steps are as follows:

[0067] S1: Feed the crude hexafluoropropylene polymer into the upper part of the filter to filter out most of the impurities, and discharge from the lower part of the filter;

[0068] S2: The filtered hexafluoropropylene polymer is further adsorbed in an adsorption tower to remove impurities and obtain high-purity hexafluoropropylene polymer.

[0069] A filter layer is laid in the filter, and the filter layer is a layered activated carbon fiber felt.

[0070] The filter is provided with an electrolysis layer, and the electrolysis electrode is an iron electrode.

[0071] The adsorption tower is filled with an adsorbent, and the preparation method of the adsorbent is as follows:

[0072] Mix 90 g of modified alumina, 20 g of modified high-temperature clay, 3 g of magnesium oxide, and 3 g of silica gel evenly by stirring to obtain the adsorbent.

[0073] The preparation method of the modified alumina is as follows:

[0074] Mix 60 g of alumina powder, 15 g of nickel acetate, and 150 g of ethanol by stirring. Then, under the atmosphere of nitrogen, heat up to 750 °C, perform high-temperature roasting for 12 h, and then cool to room temperature to obtain the modified alumina.

[0075] The preparation method of the modified high-temperature clay is as follows:

[0076] Mix 40 g of high-temperature clay powder, 5 g of nickel acetate CAS: 373-02-4, and 100 g of ethanol by stirring. Then, under the atmosphere of nitrogen, heat up to 120 °C and react for 5 h; after cooling to room temperature, add 1 g of magnesium mercaptoacetate CAS: 63592-16-5, 1 g of 3-vinylquinoline CAS: 67752-31–2, and 0.1 g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone CAS: 7473-98-5, and carry out the thiol-ene click chemical reaction under ultraviolet light irradiation; the light intensity is 10 mW / cm 2 , the reaction temperature is 30 °C, and the reaction time is 3 h; after the reaction is completed, continue to cool to room temperature under the nitrogen atmosphere to obtain the modified high-temperature clay.

[0077] Comparative Example 1

[0078] Do not modify the high-temperature clay, and the others are the same as in Example 1.

[0079] Comparative Example 2

[0080] Do not add magnesium mercaptoacetate, and the others are the same as in Example 1.

[0081] Comparative Example 3

[0082] Do not add 3-vinylquinoline, and the others are the same as in Example 1.

[0083] Purity / % Example 1 99.95 Example 2 99.96 Example 3 99.98 Example 4 99.99 Comparative Example 1 88.63 Comparative Example 2 94.37 Comparative Example 3 95.18

[0084] Through the data analysis of the above examples and comparative examples, the hexafluoropropylene polymer prepared by the present invention has a high purity.

[0085] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments of equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for efficiently removing impurity ions in hexafluoropropylene polymer, and its operation steps are as follows: S1: Feed the crude hexafluoropropylene polymer into the upper part of the filter, filter out most of the impurities, and discharge from the lower part of the filter; S2: The filtered hexafluoropropylene polymer is further adsorbed by an adsorption tower to remove impurities further, and a high-purity hexafluoropropylene polymer is obtained.

2. The high-efficiency removal method of impurity ions in a hexafluoropropylene polymer according to claim 1, characterized in that: A filter layer is laid in the filter, and the filter layer is a layered activated carbon fiber felt.

3. The high-efficiency removal method of impurity ions in hexafluoropropylene polymer according to claim 1, characterized in that: An electrolysis layer is provided in the filter, and the electrolysis electrode is an iron electrode.

4. The high-efficiency removal method of impurity ions in a hexafluoropropylene polymer according to claim 1, wherein: An adsorbent is installed in the adsorption tower, and the preparation method of the adsorbent is as follows: By weight, mix 70-90 parts of modified alumina, 10-20 parts of modified high-temperature clay, 1-3 parts of magnesium oxide, and 1-3 parts of silica gel evenly by stirring to obtain the adsorbent.

5. The high-efficiency removal method of impurity ions in a hexafluoropropylene polymer according to claim 1, characterized in that: The preparation method of the modified alumina is as follows: By weight, mix 50-60 parts of alumina powder, 5-15 parts of nickel acetate, and 100-150 parts of ethanol, stir and mix, then under the atmosphere of nitrogen, heat up to 650-750 °C, calcine at high temperature for 7-12 h, and then cool to room temperature to obtain the modified alumina.

6. The high-efficiency removal method of impurity ions in a hexafluoropropylene polymer according to claim 1, characterized in that: The preparation method of the modified high-temperature clay is as follows: By weight, 30 - 40 parts of high-temperature clay powder, 0.5 - 5 parts of nickel acetate, and 80 - 100 parts of ethanol are stirred and mixed. Then, under a nitrogen atmosphere, the temperature is raised to 100 - 120 °C and reacted for 2 - 5 h. After cooling to room temperature, 0.1 - 1 part of magnesium mercaptoacetate, 0.1 - 1 part of 3-vinylquinoline, and 0.01 - 0.1 part of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone are added, and under ultraviolet light irradiation, a thiol-ene click chemical reaction is carried out. The light intensity is 5 - 10 mW / cm 2 , the reaction temperature is 20 - 30 °C, and the reaction time is 1 - 3 h. After the reaction is completed, it is continuously cooled to room temperature under a nitrogen atmosphere to obtain modified high-temperature clay.