An adsorption material for removing fluorocarbon surfactants from fluoropolymer emulsions and its application

Abstract

The present invention discloses an adsorption material for removing fluorocarbon surfactants from fluoropolymer emulsions and its application. The adsorption material comprises a designed monomer compound and a carrier; a group with specific recognition ability for fluorocarbon compounds and a compound containing a tertiary amine functional group are sequentially introduced onto cyanuric chloride to obtain the monomer compound; wherein, the specific recognition group-containing compound is a fluorocarbon compound with a carbon chain length of at least 6; then the designed compound is modified onto the carrier and then quaternized to obtain the adsorption material; wherein, the carrier is cotton fiber.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and specifically relates to an adsorbent material for removing fluorocarbon surfactants in fluoropolymer emulsions and its application. Background Art

[0002] Fluorocarbon surfactants (PFAS) such as perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), ammonium perfluoro-2-propoxypropionate (GenX), etc. are widely used in chemical production due to their excellent properties. PFAS are widely used in the emulsion polymerization of fluoropolymers such as PTFE, PVDF, and PFA due to their superior emulsifying properties. Its main functions are to ensure the polymerization stability of fluoropolymers, construct the primary particle state, and clean the reaction kettle, and it is a necessary auxiliary agent for the industrial production of fluoropolymers. Fluoropolymer emulsions are commonly used in daily life in fields such as food, daily chemicals, biomedicine, and chemical materials. Since fluoropolymer emulsions are applied to products without treating residual PFAS, these products contain PFAS up to the ppm level. A large amount of data shows that such compounds can induce cancers, hypertension, and thyroid diseases, etc., and even damage the nervous system, immune system, and reproductive system of organisms. In addition, PFAS can enter the human body through the food chain or by contact. Due to its extremely high stability and bioaccumulation, fluorocarbon surfactants are non-degradable in nature and organisms, thus threatening the health and safety of all mankind. Due to these negative impacts, the European Union restricted the residual concentration of PFAS in production raw materials and semi-finished products in 2019. Among them, the residual amount in semi-finished products is <100 ppb, and the limit for textiles and coating materials is 625 ppb. In order to reduce the content of PFAS in fluoropolymer products, it is necessary to start from the problem of the residual concentration of PFAS in production raw materials and semi-finished products. However, existing PFAS treatment methods such as catalytic degradation and advanced oxidation are not applicable to the removal of PFAS in fluoropolymer emulsions. Such methods will destroy the fluoropolymer emulsion system and cause demulsification of PTFE fluoropolymer emulsions. Therefore, developing a technology for removing PFAS in fluoropolymer emulsions is of great significance. Summary of the Invention

[0003] Aiming at the blank in the prior art for treating PFAS in fluoropolymer emulsions, the purpose of the present invention is to provide an adsorbent material for removing fluorocarbon surfactants in fluoropolymer emulsions and its application.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions:

[0005] An adsorbent material for removing fluorocarbon surfactants in fluoropolymer emulsions, wherein the adsorbent material comprises a designed monomer compound and a carrier;

[0006] A group with specific recognition ability for fluorocarbons and a compound containing a tertiary amine functional group are successively introduced onto cyanuric chloride to obtain the monomer compound; wherein, the compound containing a group with specific recognition ability for fluorocarbons is a fluorocarbon compound with a carbon chain length of at least 6;

[0007] Then, the synthesized monomer compound is modified onto the carrier, and then quaternization treatment is carried out on it to obtain the adsorption material; wherein, the carrier is a polymer composed of glucose raw materials, including one of cotton fiber, β-cyclodextrin, straw, wood, and rice husk; or, the carrier is a material with an active hydrogen functional group, including one of chitosan, polyacetimide-functionalized cellulose, and polyaniline nanotubes.

[0008] Preferably, when the compound containing a group with specific recognition ability for fluorocarbons cannot directly react with cyanuric chloride, a bridging group is first introduced and then the compound containing a group with specific recognition ability for fluorocarbons is introduced; wherein, the compound containing a bridging group includes one of ethylene glycol, 1,4-butanediol, ethanolamine, and triethanolamine.

[0009] Preferably, the fluorocarbon compound includes one of hexafluoropropylene oxide trimer, perfluorooctanoyl chloride, perfluorohexanoyl chloride, perfluorooctanoic acid, perfluorohexanoic acid, perfluorooctanesulfonic acid, and perfluoropolyether carboxylic acid.

[0010] Preferably, the compound containing a tertiary amine functional group includes one of 2-(dimethylaminoethanol), 2-(dimethylaminopropanol), 2-(dimethylaminobutanol), 2-(dimethylaminopentanol), 2-(dimethylaminohexanol), 2-(dimethylaminoheptanol), and diethylaminoethanol.

[0011] The present invention also provides a preparation method of an adsorption material for removing fluorocarbon surfactants in fluoropolymer emulsions, for preparing the adsorption material for removing fluorocarbon surfactants in fluoropolymer emulsions as described above, which specifically includes the following steps:

[0012] Step 1: A fluorocarbon compound is introduced onto the first chlorine atom of cyanuric chloride;

[0013] Step 2: After completing Step 1, a compound containing a tertiary amine functional group is introduced onto the second chlorine atom of cyanuric chloride;

[0014] Step 3: After completing Step 2, the third chlorine atom on cyanuric chloride is grafted with the carrier, and then the tertiary amine is quaternized to obtain the adsorption material; wherein, the molar ratio of cyanuric chloride, the compound containing a tertiary amine functional group, and the fluorocarbon compound is 1:(2 - 4):(2 - 4), preferably 1:(2 - 3.5):(2 - 3.5), more preferably 1:(2 - 3):(2 - 3), and still more preferably 1:2.5:2.5.

[0015] Preferably, in step 1, when the fluorocarbon compound cannot directly react with cyanuric chloride, a bridging group is introduced first and then the fluorocarbon compound; among them, the compound containing a bridging group includes one of ethylene glycol, 1,4-butanediol, ethanolamine, and triethanolamine.

[0016] Preferably, the molar ratio of cyanuric chloride to the compound containing a bridging group is 1:(2-4). Among them, the molar ratio is further preferably 1:3.5.

[0017] Preferably, the molar ratio of cyanuric chloride to the fluorocarbon compound is 1:(2-4). Among them, the molar ratio is further preferably 1:3.5.

[0018] Preferably, the molar ratio of cyanuric chloride to the compound containing a tertiary amine functional group is 1:(2-4). Among them, the molar ratio is further preferably 1:3.5.

[0019] The present invention also provides an application of an adsorbent material for removing fluorocarbon surfactants in a fluoropolymer emulsion. The above-mentioned adsorbent material for removing fluorocarbon surfactants in a fluoropolymer emulsion is used to remove fluorocarbon surfactants in the fluoropolymer emulsion; the fluoropolymer emulsion includes one or a mixture of polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), and perfluoroethylene-propylene copolymer (FEP).

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] In order to provide more adsorption mechanisms and ensure that the structure is easy to design, the present invention selects cyanuric chloride as a raw material. According to the special interaction between fluorocarbon surfactants and the electrostatic adsorption of quaternary ammonium salts on PFAS, fluorocarbon bonds, quaternary ammonium salts, and cotton fibers are introduced on the three Cl atoms of cyanuric chloride respectively, so that the adsorbent material has high selectivity for PFAS, further improving the removal effect of the adsorbent material on PFAS, enabling it to remove PFAS in the fluoropolymer emulsion. At the same time, the present invention also selects cotton fiber as a carrier, which can not only be separated from the fluoropolymer emulsion simply and quickly, but also contains a large number of -OH groups and has a higher grafting rate, so the removal effect is better. Description of the Drawings

[0022] Figure 1 1H NMR spectrum of the product after the reaction of cyanuric chloride and ethanolamine in Example 1 1 1H NMR spectrum

[0023] Figure 2 1H NMR spectrum of the product after introducing a long fluorocarbon chain into cyanuric chloride in Example 1 1 1H NMR spectrum

[0024] Figure 3 SEM image and EDS-mapping image of the adsorption cotton fiber synthesized in the present invention.

[0025] Figure 4 FT-IR spectrum of the product after the reaction of cyanuric chloride and ethanolamine.

[0026] Figure 5 FT-IR spectrum of the synthesized product with long fluorocarbon chain in Example 1.

[0027] Figure 6 FT-IR comparison spectra of cotton fiber before and after grafting and before and after quaternization.

[0028] Figure 7 Removal rate effect diagrams of different addition amounts of adsorption cotton fiber on PFOA, prepared in Example 1.

[0029] Figure 8 Removal rate effect diagrams of different addition amounts of adsorption cotton fiber on PFOA, prepared in Example 4.

[0030] Figure 9 Removal rate effect diagrams of adsorption cotton fiber on PFOA, PFOS, GenX, and PFPE, prepared in Example 1.

[0031] Figure 10 Removal rate effect diagrams of different addition amounts of adsorption cotton fiber on PFOA, prepared in Example 4. Detailed implementation manners

[0032] The present invention will be further described below in conjunction with the drawings and examples.

[0033] I. Examples and comparative examples

[0034] Example 1

[0035] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first react cyanuric chloride with hexafluoropropylene oxide trimer and 2-(dimethylamino)ethanol, and then graft the cotton fiber with the product. The specific steps are as follows:

[0036] (1) Introduction of fluorocarbon chain onto cyanuric chloride

[0037] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system at 0 - 5 °C, add 3 mmol of triethylamine as an acid-binding agent, and then slowly dropwise add 4 mmol of ethanolamine after dilution. React for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, perform post-treatment and then rotary evaporate the solvent, and then purify to obtain the pure product by silica gel column chromatography.

[0038] Take 3 mmol of the above product in a 50 mL three-necked flask, add 20 mL of dichloromethane to dissolve it, add 3 mmol of triethylamine as an acid-binding agent, then dilute 4 mmol of hexafluoropropylene oxide trimer and slowly drop it in. React at room temperature for more than 3 h. Monitor the end of the reaction by TLC thin-layer chromatography. After post-treatment, spin-dry the solvent, and then purify it by silica gel column chromatography to obtain the pure product.

[0039] (2) Introduction of a tertiary amino group onto cyanuric chloride

[0040] Take 3 mmol of the above product in a 50 mL three-necked flask, add 20 mL of acetonitrile to dissolve it, add 3 mmol of triethylamine as an acid-binding agent, then dilute 4 mmol of 2-(dimethylaminoethanol) and slowly drop it in. React at 30 °C for more than 6 h. Monitor the end of the reaction by TLC thin-layer chromatography. No purification is required and it can be directly used for the next reaction.

[0041] (3) Grafting of cyanuric chloride with cotton fibers

[0042] Take 3 mmol of the above product in a 50 mL three-necked flask, add 20 mL of acetonitrile to dissolve it, add 3 mmol of triethylamine as an acid-binding agent, add an excessive amount of cotton fibers, and react at 70 °C for more than 48 h. After the reaction is completed, wash the cotton fibers with absolute ethanol 3 times and dry them in vacuo at 70 °C.

[0043] (4) Quaternization of the grafted cotton fibers

[0044] Take 3 g of the grafted cotton fibers into a 50 mL three-necked flask, add 20 mL of acetonitrile as a solvent, add 3 mmol of methyl trifluoromethanesulfonate under N2 protection, and react at room temperature for more than 3 h. After the reaction is completed, wash the cotton fibers with absolute ethanol 3 times and dry them in vacuo at 70 °C to obtain the final adsorption material.

[0045] Example 2

[0046] Using cotton fibers as the adsorption material and cyanuric chloride as the raw material, first let cyanuric chloride react with hexafluoropropylene oxide trimer and 2-(dimethylaminopropanol), and then graft the cotton fibers with it. The specific steps are as follows:

[0047] Step (1) is the same as that in Example 1.

[0048] (2) Introduction of a tertiary amino group onto cyanuric chloride

[0049] Take 3 mmol of the above product in a 50 mL three-necked flask, add 20 mL of acetonitrile to dissolve it, add 3 mmol of triethylamine as an acid-binding agent, then dilute 4 mmol of 2-(dimethylaminopropanol) and slowly drop it in. React at 40 °C for more than 6 h. Monitor the end of the reaction by TLC thin-layer chromatography. No purification is required and it can be directly used for the next reaction.

[0050] Steps (3) and (4) are the same as those in Example 1.

[0051] Example 3

[0052] Using cotton fiber as the adsorbent material and cyanuric chloride as the raw material, first react cyanuric chloride with 2-(dimethylaminoethanol) and perfluorooctanoyl chloride, and then graft the cotton fiber with the product. The specific steps are as follows:

[0053] (1) Introduction of fluorocarbon chain onto cyanuric chloride

[0054] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system at 0 - 5 °C, add 3 mmol of triethylamine as an acid-binding agent, slowly dropwise add 4 mmol of ethanolamine after dilution, react for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation, and purify by silica gel column chromatography to obtain the pure product.

[0055] Take 3 mmol of the above product in a 50 mL three-necked flask, add 20 mL of dichloromethane to dissolve it, add 3 mmol of triethylamine as an acid-binding agent, slowly dropwise add 4 mmol of perfluorooctanoyl chloride after dilution, react at room temperature for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation, and purify by silica gel column chromatography to obtain the pure product.

[0056] Steps (2), (3), and (4) are the same as those in Example 1.

[0057] Example 4

[0058] Using cotton fiber as the adsorbent material and cyanuric chloride as the raw material, first react cyanuric chloride with 2-(dimethylaminopropanol) and perfluorooctanoyl chloride, and then graft the cotton fiber with the product. The specific steps are as follows:

[0059] Step (1) is the same as that in Example 3, and steps (2), (3), and (4) are the same as those in Example 2.

[0060] Example 5

[0061] Using cotton fiber as the adsorbent material and cyanuric chloride as the raw material, first react cyanuric chloride with 2-(dimethylaminoethanol) and perfluorohexanoyl chloride, and then graft the cotton fiber with the product. The specific steps are as follows:

[0062] (1) Introduction of fluorocarbon chain onto cyanuric chloride

[0063] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system at 0 - 5 °C, add 3 mmol of triethylamine as an acid-binding agent, slowly dropwise add 4 mmol of ethanolamine after dilution, react for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation, and purify by silica gel column chromatography to obtain the pure product.

[0064] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system in an environment of 0 - 5 °C all the time, add 3 mmol of triethylamine as an acid-binding agent, then dilute 4 mmol of perfluorohexanoyl chloride and slowly add it dropwise. React for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation after post-treatment, and then purify it by silica gel column chromatography to obtain the pure product.

[0065] Steps (2), (3), and (4) are the same as those in Example 1.

[0066] Example 6

[0067] Use cotton fiber as the adsorption material and cyanuric chloride as the raw material. First, let cyanuric chloride react with 2-(dimethylaminopropanol) and perfluorohexanoyl chloride, and then graft the cotton fiber with it. The specific steps are as follows:

[0068] Step (1) is the same as that in Example 5, and steps (2), (3), and (4) are the same as those in Example 2.

[0069] Example 7

[0070] Use cotton fiber as the adsorption material and cyanuric chloride as the raw material. First, let cyanuric chloride react with 2-(dimethylaminoethanol) and perfluorooctanoic acid, and then graft the cotton fiber with it. The specific steps are as follows:

[0071] (1) Introduction of fluorocarbon chain into cyanuric chloride

[0072] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system in an environment of 0 - 5 °C all the time, add 3 mmol of triethylamine as an acid-binding agent, then dilute 4 mmol of perfluorooctanoic acid and slowly add it dropwise. React for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation after post-treatment, and then purify it by silica gel column chromatography to obtain the pure product.

[0073] Steps (2), (3), and (4) are the same as those in Example 1.

[0074] Example 8

[0075] Use cotton fiber as the adsorption material and cyanuric chloride as the raw material. First, let cyanuric chloride react with 2-(dimethylaminopropanol) and perfluorooctanoic acid, and then graft the cotton fiber with it. The specific steps are as follows:

[0076] Step (1) is the same as that in Example 7, and steps (2), (3), and (4) are the same as those in Example 2.

[0077] Example 9

[0078] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first make cyanuric chloride react with 2-(dimethylaminoethanol) and perfluorohexanoic acid, and then graft the cotton fiber with the product. The specific steps are as follows:

[0079] (1) Introducing fluorocarbon chain into cyanuric chloride

[0080] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system in an environment of 0 - 5 °C all the time, add 3 mmol of triethylamine as an acid-binding agent, then dilute 4 mmol of perfluorohexanoic acid and slowly add it dropwise. React for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation after post-treatment, and then purify it by silica gel column chromatography to obtain the pure product.

[0081] Steps (2), (3), and (4) are the same as those in Example 1.

[0082] Example 10

[0083] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first make cyanuric chloride react with 2-(dimethylaminopropanol) and perfluorohexanoic acid, and then graft the cotton fiber with the product. The specific steps are as follows:

[0084] Step (1) is the same as that in Example 9, and steps (2), (3), and (4) are the same as those in Example 2.

[0085] Example 11

[0086] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first make cyanuric chloride react with 2-(dimethylaminoethanol) and perfluorooctanesulfonic acid, and then graft the cotton fiber with the product. The specific steps are as follows:

[0087] (1) Introducing fluorocarbon chain into cyanuric chloride

[0088] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system in an environment of 0 - 5 °C all the time, add 3 mmol of triethylamine as an acid-binding agent, then dilute 4 mmol of perfluorooctanesulfonic acid and slowly add it dropwise. React for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation after post-treatment, and then purify it by silica gel column chromatography to obtain the pure product.

[0089] Steps (2), (3), and (4) are the same as those in Example 1.

[0090] Example 12

[0091] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first make cyanuric chloride react with 2-(dimethylaminopropanol) and perfluorooctanesulfonic acid, and then graft the cotton fiber with the product. The specific steps are as follows:

[0092] Step (1) is the same as that in Example 11, and steps (2), (3), and (4) are the same as those in Example 2.

[0093] Example 13

[0094] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first react cyanuric chloride with 2-(dimethylaminoethanol) and perfluoropolyether carboxylic acid, and then graft the cotton fiber with the product. The specific steps are as follows:

[0095] (1) Introduction of fluorocarbon chain into cyanuric chloride

[0096] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system at 0 - 5 °C, add 3 mmol of triethylamine as an acid-binding agent, and then slowly dropwise add 4 mmol of perfluoropolyether carboxylic acid after dilution. React for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation, and purify by silica gel column chromatography to obtain the pure product.

[0097] Steps (2), (3), and (4) are the same as those in Example 1.

[0098] Example 14

[0099] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first react cyanuric chloride with 2-(dimethylaminopropanol) and perfluoropolyether carboxylic acid, and then graft the cotton fiber with the product. The specific steps are as follows:

[0100] Step (1) is the same as that in Example 13, and steps (2), (3), and (4) are the same as those in Example 2.

[0101] Example 15

[0102] Based on Example 1, the adjustment is as follows: The compound containing a tertiary amine functional group is diethylaminoethanol, and its dosage is the same as that of the tertiary amine compound in Example 1.

[0103] Using cotton fiber as the adsorption material and cyanuric chloride as the raw material, first react cyanuric chloride with hexafluoropropylene oxide trimer and diethylaminoethanol, and then graft the cotton fiber with the product. The specific steps are as follows:

[0104] Step (1) is the same as that in Example 1.

[0105] (2) Introduction of tertiary amino group into cyanuric chloride

[0106] Take 3 mmol of the above product in a 50 mL three-necked flask, add 20 mL of acetonitrile to dissolve it, add 3 mmol of triethylamine as an acid-binding agent, and then slowly dropwise add 4 mmol of diethylaminoethanol after dilution. React at 30 °C for more than 6 h, monitor the end of the reaction by TLC thin-layer chromatography, and no purification is required, and the next reaction can be carried out directly.

[0107] (3) and (4) are the same as those in Example 1.

[0108] Table 1

[0109]

[0110]

[0111] Note: The fluoropolymer emulsion in Table 1 is a fluoropolymer emulsion containing perfluorinated alkyl surfactants (PFAS). The PFAS in the fluoropolymer emulsion in Table 1 is adsorbed using the method in the example.

[0112] Comparative Example 1

[0113] Based on Example 1, the adjustment is as follows: A short fluorocarbon chain compound with a carbon chain length less than 6 is used. This short fluorocarbon chain compound is octafluoropentanol, and its dosage is the same as that of the long fluorocarbon chain compound in Example 1.

[0114] Cotton fiber is used as the adsorption material and cyanuric chloride is used as the raw material. First, cyanuric chloride is reacted with octafluoropentanol and 2-(dimethylamino)ethanol, and then cotton fiber is grafted with the product. The specific steps are as follows:

[0115] (1) Introduction of fluorocarbon chain into cyanuric chloride

[0116] Dissolve 3 mmol of cyanuric chloride in 20 mL of dichloromethane, keep the system in an environment of 0 - 5 °C all the time, add 3 mmol of triethylamine as an acid-binding agent, then slowly dropwise add 4 mmol of octafluoropentanol after dilution, react for more than 3 h, monitor the end of the reaction by TLC thin-layer chromatography, then remove the solvent by rotary evaporation, and purify to obtain the pure product by silica gel column chromatography.

[0117] Steps (2), (3), and (4) are the same as those in Example 1.

[0118] Comparative Example 2

[0119] Based on Example 1, the adjustment is as follows: Straw is used to replace cotton fiber, and the dosage is exactly the same as that of cotton fiber.

[0120] Straw is used as the adsorption material and cyanuric chloride is used as the raw material. First, cyanuric chloride is reacted with hexafluoropropylene oxide trimer and diethylaminoethanol, and then straw is grafted with the product. The specific steps are as follows:

[0121] Steps (1) and (2) are the same as those in Example 1.

[0122] (3) Grafting of cyanuric chloride with straw

[0123] Take 3 mmol of the above product in a 50 mL three-necked flask, add 20 mL of acetonitrile to dissolve it, add 3 mmol of triethylamine as an acid-binding agent, add the same amount of straw as in Example 1, react at 70 °C for more than 48 h, after the reaction, wash the straw with absolute ethanol 3 times, and dry it under vacuum at 70 °C.

[0124] Step (4) is the same as in Example 1.

[0125] II. Product Application

[0126] In the product application, directly purchase 1 L each of fluoropolymer emulsions containing perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), hexafluoropropylene oxide dimer acid (GenX), and perfluoropolyether (PFPE) in commercial grade.

[0127] Example 16

[0128] (1) Adsorption experiment

[0129] Take 15 mL of PTFE fluoropolymer emulsion containing PFOA and place it in 5 20 mL sample bottles respectively. Sequentially add different masses (0.2 g, 0.3 g, 0.4 g, 0.5 g, 0.6 g) of the adsorption material prepared in Example 1, adsorb at 25 °C for 3 h. After the adsorption is completed, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it with a 0.22 μm needle filter, and then use LC-MS / MS for testing. The calculated removal rates for PFOA are 86.5%, 88.9%, 92.6%, 95.1%, 99.8% in sequence, as Figure 7 shown.

[0130] Example 17

[0131] (1) Adsorption experiment

[0132] Take 15 mL of PVDF fluoropolymer emulsion containing PFOA and place it in 5 20 mL sample bottles respectively. Sequentially add different masses (0.2 g, 0.3 g, 0.4 g, 0.5 g, 0.6 g) of the adsorption material prepared in Example 4, adsorb at 25 °C for 3 h. After the adsorption is completed, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it with a 0.22 μm needle filter, and then use LC-MS / MS for testing. The calculated removal rates for PFOA are 86.5%, 91.6%, 94.3%, 98.2%, 99.3% in sequence, as Figure 8 shown.

[0133] Example 18

[0134] (1) Adsorption experiment

[0135] 15 mL of PTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively were placed in 4 20-mL sample bottles. 0.6 g of the adsorbent material prepared in Example 1 was added to each sample bottle, and the adsorption was carried out at 25 °C for 3 h. After the adsorption was completed, 5 mL of the emulsion was added with ethanol to cause demulsification, and then it was centrifuged. 1 mL of the supernatant was filtered through a 0.22-μm canned needle filter, and then tested using LC-MS / MS. The calculated removal rates were 99.0%, 99.5%, 99.3%, and 99.8% in sequence, as Figure 9 shown.

[0136] Example 19

[0137] (1) Adsorption experiment

[0138] 15 mL of PCTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively were placed in 4 20-mL sample bottles. 0.6 g of the adsorbent material prepared in Example 2 was added to each sample bottle, and the adsorption was carried out at 25 °C for 3 h. After the adsorption was completed, 5 mL of the emulsion was added with ethanol to cause demulsification, and then it was centrifuged. 1 mL of the supernatant was filtered through a 0.22-μm canned needle filter, and then tested using LC-MS / MS. The calculated removal rates were 99.4%, 99.2%, 99.3%, and 99.2% in sequence.

[0139] Example 20

[0140] (1) Adsorption experiment

[0141] 15 mL of ECTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively were placed in 4 20-mL sample bottles. 0.6 g of the adsorbent material prepared in Example 3 was added to each sample bottle, and the adsorption was carried out at 25 °C for 3 h. After the adsorption was completed, 5 mL of the emulsion was added with ethanol to cause demulsification, and then it was centrifuged. 1 mL of the supernatant was filtered through a 0.22-μm needle filter, and then tested using LC-MS / MS. The calculated removal rates were 98.9%, 99.0%, 99.0%, and 98.9% in sequence.

[0142] Example 21

[0143] (1) Adsorption experiment

[0144] Take 15 mL of PVDF fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 4 to each bottle and adsorb for 3 h at 25°C. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it. Take 1 mL of the supernatant and filter it through a 0.22-μm needle filter. Subsequently, use LC-MS / MS for testing. The calculated removal rates are 99.0%, 99.1%, 98.9%, and 98.8% in sequence, as Figure 10 shown.

[0145] Example 22

[0146] (1) Adsorption experiment

[0147] Take 15 mL of FEP fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 5 to each bottle and adsorb for 3 h at 25°C. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it. Take 1 mL of the supernatant and filter it through a 0.22-μm needle filter. Subsequently, use LC-MS / MS for testing. The calculated removal rates are 98.8%, 98.9%, 99.1%, and 99.2% in sequence.

[0148] Example 23

[0149] (1) Adsorption experiment

[0150] Take 15 mL of PTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 6 to each bottle and adsorb for 3 h at 25°C. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it. Take 1 mL of the supernatant and filter it through a 0.22-μm needle filter. Subsequently, use LC-MS / MS for testing. The calculated removal rates are 98.9%, 99.2%, 98.8%, and 99.1% in sequence.

[0151] Example 24

[0152] (1) Adsorption experiment

[0153] Take 15 mL of PCTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively, place them in 4 20-mL sample bottles, add 0.6 g of the adsorbent material prepared in Example 7 to each, adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it through a 0.22-μm syringe filter, and then test it using LC-MS / MS. The calculated removal rates are 99.1%, 99.3%, 99.0%, and 99.1% in sequence.

[0154] Example 25

[0155] (1) Adsorption experiment

[0156] Take 15 mL of ECTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively, place them in 4 20-mL sample bottles, add 0.6 g of the adsorbent material prepared in Example 8 to each, adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it through a 0.22-μm syringe filter, and then test it using LC-MS / MS. The calculated removal rates are 99.2%, 99.0%, 98.9%, and 99.2% in sequence.

[0157] Example 26

[0158] (1) Adsorption experiment

[0159] Take 15 mL of PVDF fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively, place them in 4 20-mL sample bottles, add 0.6 g of the adsorbent material prepared in Example 9 to each, adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it through a 0.22-μm syringe filter, and then test it using LC-MS / MS. The calculated removal rates are 99.1%, 98.8%, 99.1%, and 99.0% in sequence.

[0160] Example 27

[0161] (1) Adsorption experiment

[0162] Take 15 mL of FEP fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 10 to each sample bottle, and adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it through a 0.22-μm needle filter, and then test it using LC-MS / MS. The calculated removal rates are 98.9%, 99.1%, 98.8%, and 99.2% in sequence.

[0163] Example 28

[0164] (1) Adsorption experiment

[0165] Take 15 mL of PTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 11 to each sample bottle, and adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it through a 0.22-μm needle filter, and then test it using LC-MS / MS. The calculated removal rates are 99.1%, 98.9%, 98.7%, and 99.1% in sequence.

[0166] Example 29

[0167] (1) Adsorption experiment

[0168] Take 15 mL of PCTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 12 to each sample bottle, and adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it, take 1 mL of the supernatant, filter it through a 0.22-μm needle filter, and then test it using LC-MS / MS. The calculated removal rates are 98.8%, 99.1%, 98.3%, and 98.9% in sequence.

[0169] Example 30

[0170] (1) Adsorption experiment

[0171] Take 15 mL of ECTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively, and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 13 to each bottle, and adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it. Take 1 mL of the supernatant and filter it through a 0.22-μm needle filter. Subsequently, use LC-MS / MS for testing. The calculated removal rates are 98.9%, 99.1%, 99.3%, and 98.9% in sequence.

[0172] Example 31

[0173] (1) Adsorption experiment

[0174] Take 15 mL of PVDF fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively, and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 14 to each bottle, and adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it. Take 1 mL of the supernatant and filter it through a 0.22-μm needle filter. Subsequently, use LC-MS / MS for testing. The calculated removal rates are 99.1%, 99.2%, 99.0%, and 98.9% in sequence.

[0175] Example 32

[0176] (1) Adsorption experiment

[0177] Take 15 mL of FEP fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively, and place them in 4 20-mL sample bottles. Add 0.6 g of the adsorbent material prepared in Example 15 to each bottle, and adsorb at 25 °C for 3 h. After adsorption, take 5 mL of the emulsion, add ethanol to demulsify it, then centrifuge it. Take 1 mL of the supernatant and filter it through a 0.22-μm needle filter. Subsequently, use LC-MS / MS for testing. The calculated removal rates are 98.9%, 98.8%, 99.3%, and 99.2% in sequence.

[0178] Example 33

[0179] (1) Adsorption experiment

[0180] 15 mL of PTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively were placed in 4 20-mL sample bottles. 0.6 g of the adsorbent material prepared in Comparative Example 1 was added to each sample bottle, and the adsorption was carried out at 25 °C for 3 h. After the adsorption was completed, 5 mL of the emulsion was added with ethanol to demulsify it, and then it was centrifuged. 1 mL of the supernatant was filtered through a 0.22-μm needle filter, and then tested using LC-MS / MS. The calculated removal rates were 88.9%, 89.1%, 88.6%, and 86.9% respectively.

[0181] Example 34

[0182] 15 mL of PTFE fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE respectively were placed in 4 20-mL sample bottles. 0.6 g of the adsorbent material prepared in Comparative Example 2 was added to each sample bottle, and the adsorption was carried out at 25 °C for 3 h. After the adsorption was completed, 5 mL of the emulsion was added with ethanol to demulsify it, and then it was centrifuged. 1 mL of the supernatant was filtered through a 0.22-μm needle filter, and then tested using LC-MS / MS. The calculated removal rates were 85.4%, 86.5%, 84.3%, and 86.2% respectively.

[0183] The detection results of Examples 16 - 17 are shown in Table 2.

[0184] Table 2 Results of the removal of PFOA in fluoropolymer emulsion with different addition amounts of grafted cotton fibers

[0185] Using an adsorbent material The removal rates of PFOA for different addition amounts of the adsorbent material are as follows Example 16 Synthesized from Example 1 86.5％、88.9％、92.6％、95.1％、99.8％ Example 17 Synthesized from Example 4 86.5％、91.6％、94.3％、98.2％、99.3％

[0186] The detection results of Examples 18 - 34 are shown in Table 3.

[0187] Table 3 Results of the removal of different fluorocarbon surfactants by grafted cotton fibers with different modifiers

[0188]

[0189]

[0190] Taking PFOA as an example, there are obvious differences in the removal rates of PFOA in fluoropolymer emulsion by the adsorbent materials synthesized in the examples and comparative examples:

[0191] (1) The adsorbent materials synthesized in the examples all have relatively high removal rates for PFAS in fluoropolymer emulsion. The adsorbent material of the present invention can achieve a removal rate of at least 86% or more for PFAS in fluoropolymer emulsion, and at least 98% or more at most. It can be seen that this removal rate increases with the increase of the amount of adsorbed cotton fibers, and almost reaches the highest removal rate after 0.6 g.

[0192] (2) In the examples, not only the adsorption material modified with hexafluoropropylene oxide trimer and perfluorooctanesulfonic acid has excellent removal effect on PFOA, but also the adsorption materials modified with other long fluorocarbon chain compounds have excellent removal effect. Thus, it can be seen that it is not necessarily the adsorption material modified with the target compound that has good adsorption effect on the target compound. At the same time, even for the adsorption materials modified with the same type of compounds (all long fluorocarbon chain compounds), there are still certain differences in the removal effect on the same target compound;

[0193] (3) In Comparative Example 1, a short fluorocarbon chain compound with a carbon chain length less than 6 was used, and this short fluorocarbon chain compound was octafluoropentanol. The adsorption efficiency of the thus synthesized adsorption material for PFAS is much lower than that of the examples. It can be seen that the removal rate of short carbon-fluorine chain compounds for long carbon-fluorine chain compounds in fluoropolymer emulsions is not ideal;

[0194] (4) In Comparative Example 2, straw was used to replace cotton fiber as the carrier, and its adsorption effect decreased significantly compared with Example 1. Since the reaction sites provided by it are few and the specific surface area is small, the removal efficiency of PFAS is low. It can be seen that the type of carrier has a great influence on the adsorption effect of the adsorption material, and straw cannot replace cotton fiber, which will lead to a significant decrease in the adsorption effect of the adsorption material;

[0195] (5) From the data of the above examples, it can be known that the adsorption materials prepared by grafting different types of fluorocarbon chains and quaternary ammonium salts have a high removal rate for PFAS in fluoropolymer emulsions. Therefore, the adsorption material prepared by the present invention for removing fluorocarbon surfactants in fluoropolymer emulsions has good removal effect on PFOA, PFOS, GenX, and PFPE, and selecting cotton fiber as the adsorption material can achieve the effect of rapid separation from the fluoropolymer emulsion.

[0196] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention rather than to limit them. Those of ordinary skill in the art should understand that any modifications or equivalent replacements to the technical solutions of the present invention, without departing from the purpose and scope of the present technical solution, should be covered within the scope of the claims of the present invention.

Claims

1. A preparation method of an adsorption material for removing fluorocarbon surfactants from a fluoropolymer emulsion, characterized in that, Specifically, it includes the following steps: Step 1: Introduce a fluorocarbon compound to the first chlorine atom on cyanuric chloride; Step 2: After completing Step 1, introduce a compound containing a tertiary amine functional group to the second chlorine atom on cyanuric chloride; Step 3: After completing Step 2, graft the third chlorine atom on cyanuric chloride to the carrier, and then quaternize the tertiary amine to obtain the adsorption material; The fluorocarbon compound is one of hexafluoropropylene oxide trimer, perfluorooctanoyl chloride, perfluorohexanoyl chloride, perfluorooctanoic acid, perfluorohexanoic acid, perfluorooctanesulfonic acid, and perfluoropolyether carboxylic acid; The carrier is cotton fiber; The compound containing a tertiary amine functional group includes one of 2-(dimethylaminoethanol), 2-(dimethylaminopropanol), 2-(dimethylaminobutanol), 2-(dimethylaminopentanol), 2-(dimethylaminohexanol), 2-(dimethylaminoheptanol), and diethylaminoethanol; The molar ratio of cyanuric chloride to the fluorocarbon compound is 1:(2 - 4); the molar ratio of cyanuric chloride to the compound containing a tertiary amine functional group is 1:(2 - 4).

2. The preparation method according to claim 1, characterized in that, In Step 1, when the fluorocarbon compound cannot directly react with cyanuric chloride, first introduce a bridging group and then introduce the fluorocarbon compound; among them, the compound containing a bridging group is one of ethanolamine and triethanolamine.

3. The preparation method according to claim 2, wherein The molar ratio of cyanuric chloride to the compound containing a bridging group is 1:(2 - 4).

4. Application of an adsorbent material for removing fluorocarbon surfactants from fluoropolymer emulsions, characterized in that, The adsorption material prepared by the preparation method according to any one of claims 1 to 3 is used to remove fluorocarbon surfactants in fluoropolymer emulsions; the fluoropolymer emulsions include one or several mixtures of polytetrafluoroethylene, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, polyvinylidene fluoride, and perfluoroethylene-propylene copolymer.

Images