A capture material for removing fluorocarbon surfactants from fluoropolymer emulsions

Abstract

The application discloses a kind of capture materials for removing fluorocarbon surfactant in fluoropolymer emulsion, the capture material is the material that carrier surface is grafted with fluorocarbon compound;Wherein, the carrier is one of PP fiber, polyacrylonitrile fiber, polyethylene fiber, polyolefin fiber, polyvinyl formal fiber, polyvinyl chloride fiber;The fluorocarbon compound is fluorocarbon compound with at least 6 of carbon chain length, and at least one of carbon-carbon double bond, mercapto group, aldehyde group, carbonyl, carboxyl, nitrogen-containing active group.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic synthesis, and particularly relates to a capturing material for removing fluorocarbon surfactants in fluoropolymer emulsion. BACKGROUND

[0002] Fluorocarbon surfactants (PFAS) such as perfluorooctanoic acid (PFOA), perfluorooctyl sulfonic acid (PFOS), perfluoro-2-propoxypropionic acid ammonium (GenX) and the like are necessary auxiliaries for industrialized production of fluorine-containing polymer emulsion. The extremely high thermal stability and chemical stability make PFAS non-degradable in nature and organisms, which can enter the human body through food chain or by breathing, contacting and the like, and finally accumulate in the human body, damaging the nervous system, reproductive system and immune system of organisms. Therefore, removal of PFAS in the environment has been continuously concerned. Due to these negative effects, countries have promulgated restrictions on the residual content of PFAS in products or semi-finished products, so that in order to make the residual amount of PFAS in semi-finished products and products not exceed the standard, it is urgent to remove the residual PFAS in the emulsion. However, the current treatment means is to act on the water environment or soil, and there is a blank in the treatment technology of residual PFAS in the emulsion.

[0003] It is a key problem to remove PFAS without destroying the stability of the emulsion system. The existing technology finds that chemical treatment methods such as catalytic degradation and advanced oxidation have high cost, low efficiency and can destroy the fluoropolymer emulsion system to cause PTFE fluoropolymer emulsion demulsification, and therefore are not suitable for removal of PFAS in the emulsion. On the contrary, physical adsorption is more suitable for removal of PFAS in the emulsion, but the adsorption materials used in the existing technology, such as activated carbon and adsorption resin, have the same problem that the removal of the system will also destroy the stability of the emulsion. SUMMARY

[0004] In view of the above problems in the prior art, the present application aims to provide a capturing material for removing fluorocarbon surfactants in fluoropolymer emulsion, so as to solve the problems that the prior art lacks adsorption materials for removing fluorocarbon surfactants in fluoropolymer emulsion, and the existing removal methods will destroy the stability of the fluoropolymer emulsion.

[0005] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0006] A capturing material for removing fluorocarbon surfactant in fluoropolymer emulsion, the capturing material is a material with fluorocarbon compound grafted on the surface of a carrier; wherein the carrier is one of PP fiber, polyacrylonitrile fiber, polyethylene fiber, polyolefin fiber, polyvinyl formal fiber, and polyvinyl chloride fiber; the fluorocarbon compound is a fluorocarbon compound with carbon chain length of at least 6 and at least one of carbon-carbon double bond, mercapto group, aldehyde group, carbonyl group, carboxyl group, and nitrogen-containing active group.

[0007] Preferably, the fluorocarbon compound includes one of perfluorohexyl ethylene, perfluorooctyl ethylene, perfluorodecyl ethyl acrylate, perfluorohexyl ethanethiol, perfluorooctyl ethanethiol, perfluorodecyl ethanethiol, perfluorooctanal, perfluorohexanone, and perfluorohexanoic acid.

[0008] The application provides a preparation method of a capturing material for removing fluorocarbon surfactant in fluoropolymer emulsion.

[0009] Step 1: activating the surface of the carrier to form free radicals on the surface of the carrier;

[0010] Step 2: grafting the carrier treated in step 1 with a fluorocarbon compound to obtain the capturing material; wherein the grafting process is a reaction at 50-80 ℃ for more than 6 hours; and the molar ratio of the carrier to the fluorocarbon compound is at least 1:2.

[0011] Preferably, in step 1, the surface of the carrier is treated by one of plasma treatment, initiator, and irradiation to generate free radicals.

[0012] Preferably, when the carrier is treated by plasma, the carrier is treated by the plasma machine for more than 200 seconds.

[0013] Preferably, when the carrier is treated by an initiator, a peroxide or an azo compound is selected as the initiator, and the mass ratio of the initiator to the carrier is 1:(4-6); and the initiator is one of dibenzoyl peroxide and azobisisobutyronitrile.

[0014] Preferably, when the carrier is treated by irradiation, the PP fiber is placed under a Coy ray source for irradiation for more than 12 hours. 60 Coy ray source for irradiation for more than 12 hours.

[0015] The application further provides an application of the capturing material for removing fluorocarbon surfactant in fluoropolymer emulsion, the capturing material is prepared by the above preparation method, and the capturing material is used for removing fluorocarbon surfactant in fluoropolymer emulsion; wherein the adding amount of the capturing material is at least 1.4 g / L.

[0016] Compared with the prior art, the application has the following beneficial effects:

[0017] 1、The present application considers treating the surface of the carrier, so that the chemical bond of the fiber carrier surface is broken to produce a large number of active sites, which can be directly used to initiate monomer polymerization; at the same time, the present application also finds that perfluorinated compounds can specifically recognize PFAS, so that the carrier fiber has unique high selectivity for PFAS compared with other capture materials (such as activated carbon, ion exchange resin, etc.).

[0018] 2、The present application selects one of PP fiber, polyacrylonitrile fiber, polyethylene fiber, polyolefin fiber, polyvinyl formal fiber, and polyvinyl chloride fiber as a carrier, so that the capture material can simply and quickly adsorb fluorocarbon surfactants in fluoropolymer emulsion, and also will not damage the stability of the fluoropolymer emulsion, thereby solving the technical problem that the existing adsorption material will damage the stability of the fluoropolymer emulsion.

[0019] 3、The preparation method of the present application also finds that different activation treatment methods for the carrier will have a certain influence on the adsorption effect of the capture material; at the same time, the preparation method of the present application is simple and easy to control, and has good industrial application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The SEM and element mapping diagrams (1g for carbon element and 1h for fluorine element) of blank PP fiber (1a and 1b), plasma treated PP fiber (1c and 1d), and grafted PP fiber (1e and 1f).

[0021] Figure 2 The FT-IR comparison diagram of PP fiber before and after grafting.

[0022] Figure 3 The PFOA removal rate effect diagram of the capture PP fiber with different addition amounts, prepared from Example 1.

[0023] Figure 4 The PFOA removal rate effect diagram of the capture PP fiber with different addition amounts, prepared from Example 2.

[0024] Figure 5 The PFOA removal rate effect diagram of the capture PP fiber with different addition amounts, prepared from Example 3.

[0025] Figure 6 The PFOA removal rate effect diagram of the capture PP fiber with different adsorption times, prepared from Example 2.

[0026] Figure 7 The PFOA, PFOS, GenX, and PFPE removal rate effect diagram of the capture PP fiber, prepared from Example 1.

[0027] Figure 8 To capture the PP fiber removal rate effect diagram of PFOA, PFOS, GenX, PFPE, prepared from example 2.

[0028] Figure 9 To capture the PP fiber removal rate effect diagram of PFOA, PFOS, GenX, PFPE, prepared from example 3. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0030] Unless otherwise specified in specific cases, the numerical ranges listed in the present application include the upper and lower limits, and all integers and fractions within the range, and are not limited to the specific values listed in the defined range. As referred to herein, "and / or" is inclusive, for example, "A and / or B" means only A, or only B, or both A and B.

[0031] I. A capture material for removing fluorocarbon surfactants in fluoropolymer emulsion

[0032] The capture material described in the present application is a material with fluorocarbon compounds grafted on the surface of the carrier; wherein the carrier is one of PP fiber, polyacrylonitrile fiber, polyethylene fiber, polyolefin fiber, polyvinyl formal fiber, and polyvinyl chloride fiber; the fluorocarbon compound is a fluorocarbon compound with a carbon chain length of at least 6, and containing at least one of carbon-carbon double bond, mercapto group, aldehyde group, carbonyl group, carboxyl group, and nitrogen-containing active group.

[0033] In specific implementation, the fluorocarbon compound includes one of perfluorohexyl ethylene, perfluorooctyl ethylene, perfluorodecyl ethyl acrylate, perfluorohexyl ethyl mercaptan, perfluorooctyl mercaptan, perfluorodecyl mercaptan, perfluorooctanal, perfluorohexanone, and perfluorohexanoic acid.

[0034] II. A preparation method of a capture material for removing fluorocarbon surfactants in fluoropolymer emulsion

[0035] Step 1: activating the surface of the carrier to form free radicals on the surface of the carrier;

[0036] Step 2: grafting the carrier treated in step 1 with a fluorocarbon compound to obtain the capture material; wherein the grafting process is a reaction at 50-80℃ for more than 6h. The molar ratio of the carrier to the fluorocarbon compound is at least 1:2.

[0037] In some embodiments, the reaction temperature of the grafting process is controlled between 50-80°C, too low temperature is not conducive to the grafting reaction, which can result in too low amount of fluorocarbon compound grafted on the surface of the carrier; while too high temperature cannot increase the grafting rate, and can also cause side reactions, so that the substance grafted on the surface of the carrier is a compound with other structures; both of these two cases can affect the adsorption effect of the final capture material, therefore, the reaction temperature can be 50°C, 60°C, 70°C, 80°C, etc., and all ranges and sub-ranges between the above-mentioned values. It should be understood that in the embodiments, any of the above-mentioned ranges can be combined with any other range.

[0038] In some embodiments, the reaction time of the grafting reaction is controlled to be more than 6h, which ensures that the surface of the carrier after activation can graft as much fluorocarbon compound as possible, so that the capture material has excellent adsorption performance, therefore, the reaction time can be preferably 6h, 7h, 8h, 9h, 10h, etc., and all ranges and sub-ranges between the above-mentioned values. It should be understood that in the embodiments, any of the above-mentioned ranges can be combined with any other range.

[0039] In some embodiments, the molar ratio of the carrier to the fluorocarbon compound is at least 1:2, which can be further controlled between 1:(2-4), if the amount of fluorocarbon compound is too low, it can result in too little fluorocarbon compound grafted on the surface of the carrier; if it is too high, it cannot increase the grafting rate, and also wastes raw materials, and even can cause entanglement between fluorocarbon compounds, which adversely affects the adsorption effect of the capture material. The molar ratio of the carrier to the fluorocarbon compound higher than 1:4 can also make the capture material achieve a higher removal effect, but under the premise that the capture material can maintain a high removal effect, as the molar ratio of the carrier to the fluorocarbon compound gradually increases, the adsorption effect of the capture material fluctuates instead of continuously increasing in direct proportion, and even decreases. Therefore, the molar ratio of the carrier to the fluorocarbon compound can be 1:2, 1:2.5, 1:3, 1:3.5, 1:4, etc., and all ranges and sub-ranges between the above-mentioned values. It should be understood that in the embodiments, any of the above-mentioned ranges can be combined with any other range.

[0040] In some embodiments, in step 1, the carrier is treated by one of plasma, initiator or irradiation to generate radicals on its surface. The purpose of the activation treatment on the surface of the carrier is to break the chemical bonds on the surface of the carrier to generate radicals, which can be directly used to initiate the polymerization of monomers, to graft fluorocarbon chains containing functional groups on the surface of the fiber, thereby having a targeted adsorption effect on the fluorocarbon surfactant in the fluoropolymer emulsion. However, different activation treatment methods will affect the number of radicals on the surface of the carrier, thereby ultimately affecting the adsorption effect of the capture material. However, the activation treatment method does not affect the process parameters in step 2, and can be combined with step 2 in any way. However, different activation treatment methods will affect the number of radicals on the surface of the carrier, although the use of a catalyst or heating can also generate radicals on the surface, but the catalyst will not only break the chemical bonds on the surface of the carrier, but also break the chemical bonds inside the carrier, resulting in deterioration of the carrier, which is not conducive to the subsequent grafting reaction, and will further affect the stability of the final capture material. Heating requires heating the carrier to a high temperature to break the chemical bonds on its surface, and this process is difficult to control, because at a high temperature, chemical bonds inside the carrier can also be broken, which is not conducive to the subsequent grafting reaction.

[0041] In some embodiments, when the carrier is treated by plasma, the carrier is treated by plasma for more than 200 seconds. The carrier is treated by plasma of an inert gas such as nitrogen, argon, or helium for a long enough time to have enough radicals on the surface of the carrier, so the plasma treatment time can be more than 200 seconds, more than 250 seconds, more than 300 seconds, more than 350 seconds, and the like, as well as all ranges and sub-ranges between the aforementioned values. It should be understood that in embodiments, any of the aforementioned ranges can be combined with any other range.

[0042] In some embodiments, when the carrier is treated by an initiator, a peroxide or an azo compound is selected as the initiator, and the mass ratio of the initiator to the carrier is 1:(4-6). The initiator is one of dibenzoyl peroxide or azobisisobutyronitrile, and the mass ratio of the initiator to the carrier can be 1:4, 1:5, 1:6, and the like, as well as all ranges and sub-ranges between the aforementioned values. It should be understood that in embodiments, any of the aforementioned ranges can be combined with any other range.

[0043] In some embodiments, when the carrier is treated by irradiation, the carrier is placed in 60The PP fiber is irradiated by the Co-ray source for at least 12 hours. If the irradiation time is less than 12 hours, the number of free radicals on the surface of the carrier is too small, and the number of fluorocarbon compounds grafted subsequently is insufficient. If the irradiation time is more than 24 hours, a homopolymer is likely to be produced, which affects the grafting rate. Therefore, the irradiation time should not be more than 24 hours.

[0044] Three, an application of a capture material for removing fluorocarbon surfactants in a fluoropolymer emulsion

[0045] The capture material is prepared by the preparation method, and is used for removing fluorocarbon surfactants in a fluoropolymer emulsion. The addition amount of the capture material is at least 1.4 g / L or more.

[0046] Four, examples and comparative examples

[0047] Example 1

[0048] The PP fiber is irradiated by the Co-ray source for at least 12 hours. If the irradiation time is less than 12 hours, the number of free radicals on the surface of the carrier is too small, and the number of fluorocarbon compounds grafted subsequently is insufficient. If the irradiation time is more than 24 hours, a homopolymer is likely to be produced, which affects the grafting rate. Therefore, the irradiation time should not be more than 24 hours.

[0049] (1) Ion treatment

[0050] 0.5 g of PP fiber is weighed and placed in the plasma cleaning machine, the cabin door is closed, and the parameters are set. The time is 300 s.

[0051] (2) Grafting of PP fiber and perfluoro material

[0052] The PP fiber in step (1) is taken in a 50 mL three-necked flask, 30 mL of acetonitrile is added to disperse it, 1.5 g of perfluorohexyl ethylene is diluted and slowly added dropwise, and the reaction is carried out at 80°C for more than 6 hours. After the reaction is completed, the PP fiber is washed with anhydrous ethanol for 3 times, and then vacuum dried to obtain the final capture material.

[0053] Example 2

[0054] The PP fiber is irradiated by the Co-ray source for at least 12 hours. If the irradiation time is less than 12 hours, the number of free radicals on the surface of the carrier is too small, and the number of fluorocarbon compounds grafted subsequently is insufficient. If the irradiation time is more than 24 hours, a homopolymer is likely to be produced, which affects the grafting rate. Therefore, the irradiation time should not be more than 24 hours.

[0055] Step (1) is the same as that in Example 1.

[0056] (2) Grafting of PP fiber and perfluoro material

[0057] The PP fiber in step (1) is taken in a 50 mL three-necked flask, 30 mL of acetonitrile is added to disperse it, 1.5 g of perfluorohexyl ethylene is diluted and slowly added dropwise, and the reaction is carried out at 80°C for more than 6 hours. After the reaction is completed, the PP fiber is washed with anhydrous ethanol for 3 times, and then vacuum dried to obtain the final capture material.

[0058] Example 3

[0059] Using the plasma treatment method, PP fiber as a carrier, perfluorodecyl ethyl acrylate as a modifier, first use the plasma cleaning machine to treat the PP fiber, and then graft the PP fiber with perfluorodecyl ethyl acrylate. The specific steps are as follows:

[0060] Step (1) is the same as that in Example 1.

[0061] (2) Grafting of PP fiber with perfluorinated substance

[0062] Take the PP fiber of step (1) in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, then slowly add 1.5 g of perfluorodecyl ethyl acrylate after dilution, and react at 80°C for more than 6 hours. After the reaction is completed, wash with anhydrous ethanol for 3 times, and then vacuum dry to obtain the final capture material.

[0063] Example 4

[0064] Using the plasma treatment method, PP fiber as a carrier, perfluorohexyl ethyl mercaptan as a modifier, first use the plasma cleaning machine to treat the PP fiber, and then graft the PP fiber with perfluorohexyl ethyl mercaptan. The specific steps are as follows:

[0065] Step (1) is the same as that in Example 1.

[0066] (2) Grafting of PP fiber with perfluorinated substance

[0067] Take the PP fiber of step (1) in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, then slowly add 1.5 g of perfluorohexyl ethyl mercaptan after dilution, and react at 80°C for more than 6 hours. After the reaction is completed, wash with anhydrous ethanol for 3 times, and then vacuum dry to obtain the final capture material.

[0068] Example 5

[0069] Using the plasma treatment method, PP fiber as a carrier, perfluorooctyl ethyl mercaptan as a modifier, first use the plasma cleaning machine to treat the PP fiber, and then graft the PP fiber with perfluorooctyl ethyl mercaptan. The specific steps are as follows:

[0070] Step (1) is the same as that in Example 1.

[0071] (2) Grafting of PP fiber with perfluorinated substance

[0072] Take the PP fiber of step (1) in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, then slowly add 1.5 g of perfluorooctyl ethyl mercaptan after dilution, and react at 80°C for more than 6 hours. After the reaction is completed, wash with anhydrous ethanol for 3 times, and then vacuum dry to obtain the final capture material.

[0073] Example 6

[0074] Using the plasma treatment method, PP fiber as the carrier, perfluorodecyl ethyl mercaptan as the modifier, first use the plasma cleaning machine to treat the PP fiber, then graft the PP fiber with perfluorodecyl ethyl mercaptan. The specific steps are as follows:

[0075] Step (1) is the same as that of Example 1.

[0076] (2) Grafting of PP fiber with perfluorinated substance

[0077] Take the PP fiber of step (1) in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, then slowly add 1.5 g of perfluorodecyl ethyl mercaptan after dilution, and react at 80°C for more than 6 hours. After the reaction is completed, wash with anhydrous ethanol for 3 times, and then vacuum dry to obtain the final capture material.

[0078] Example 7

[0079] Using the plasma treatment method, PP fiber as the carrier, perfluoro octyl aldehyde as the modifier, first use the plasma cleaning machine to treat the PP fiber, then graft the PP fiber with perfluoro octyl aldehyde. The specific steps are as follows:

[0080] Step (1) is the same as that of Example 1.

[0081] (2) Grafting of PP fiber with perfluorinated substance

[0082] Take the PP fiber of step (1) in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, then slowly add 1.5 g of perfluoro octyl aldehyde after dilution, and react at 80°C for more than 6 hours. After the reaction is completed, wash with anhydrous ethanol for 3 times, and then vacuum dry to obtain the final capture material.

[0083] Example 8

[0084] Using the plasma treatment method, PP fiber as the carrier, perfluoro hexyl ketone as the modifier, first use the plasma cleaning machine to treat the PP fiber, then graft the PP fiber with perfluoro hexyl ketone. The specific steps are as follows:

[0085] Step (1) is the same as that of Example 1.

[0086] (2) Grafting of PP fiber with perfluorinated substance

[0087] Take the PP fiber of step (1) in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, then slowly add 1.5 g of perfluoro hexyl ketone after dilution, and react at 80°C for more than 6 hours. After the reaction is completed, wash with anhydrous ethanol for 3 times, and then vacuum dry to obtain the final capture material.

[0088] Example 9

[0089] PP fiber is used as a carrier, initiator induces chemical bond breakage to produce free radicals, and perfluoro octyl ethylene is used as a modifier to graft PP fiber with perfluoro octyl ethylene. The specific steps are as follows:

[0090] (1) Activation

[0091] Take 0.5g PP fiber in a 50mL three-necked flask, add 30mL acetonitrile to disperse it, add 0.1g azobisisobutyronitrile as a free radical initiator, and mix well.

[0092] (2) Grafting of PP fiber with perfluoro material

[0093] Slowly add 1.5g perfluoro octyl ethylene (perfluoro octyl ethylene diluted with acetonitrile) to the mixture obtained in step (1), and react at 80℃ for more than 6h. After the reaction is completed, wash with anhydrous ethanol for 3 times, and vacuum dry to obtain the final capture material.

[0094] Example 10

[0095] PP fiber is used as a carrier, irradiation induces chemical bond breakage to produce free radicals, and perfluoro octyl ethylene is used as a modifier to graft PP fiber with perfluoro octyl ethylene. The specific steps are as follows:

[0096] (1) Irradiation

[0097] Take 0.5g PP fiber and place it in a 60 Coy radiation source for 12h.

[0098] (2) Grafting of PP fiber with perfluoro material

[0099] Take the PP fiber of step (1) in a 50mL three-necked flask, add 30mL acetonitrile to disperse it, and then slowly add 1.5g perfluoro octyl ethylene diluted with acetonitrile. React at 70℃ for more than 6h. After the reaction is completed, wash with anhydrous ethanol for 3 times, and vacuum dry to obtain the final capture material.

[0100] Example 11

[0101] Based on Example 1, adjustments are made, the difference is that polyacrylonitrile fiber is used instead of PP fiber, and other process steps are exactly the same as Example 1.

[0102] Comparative Example 1

[0103] PP fiber is used as a carrier, and perfluoro methyl mercaptan is used as a modifier. First, the PP fiber is treated with a plasma cleaning machine, and then the PP fiber is grafted with perfluoro methyl mercaptan. The specific steps are as follows:

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

[0105] (2) PP fiber grafting with perfluorinated substance

[0106] Take the PP fiber of step (1) in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, then slowly add 1.5 g of perfluoromethyl mercaptan diluted with acetonitrile, and react at 80°C for more than 6 h. After the reaction is completed, wash with anhydrous ethanol for 3 times, and vacuum dry to obtain the final capture material.

[0107] Comparative Example 2

[0108] On the basis of Example 1, the difference is that the catalyst treatment method is used, and other process steps and dosages are completely consistent with Example 1. Trialkyl aluminum-titanium trichloride is used as the catalyst, and the specific steps are as follows:

[0109] (1) Activation

[0110] Take 0.5 g of PP fiber in a 50 mL three-necked flask, add 30 mL of acetonitrile to disperse it, and add 0.1 g of trialkyl aluminum-titanium trichloride as a catalyst, and mix uniformly;

[0111] (2) PP fiber grafting with perfluorinated substance

[0112] Slowly add 1.5 g of perfluorooctyl vinyl (perfluorooctyl vinyl diluted with acetonitrile) to the mixture obtained in step (1), and react at 80°C for more than 6 h. After the reaction is completed, filter, wash with anhydrous ethanol for 3 times, and vacuum dry to obtain the final capture material.

[0113] Comparative Example 3

[0114] On the basis of Example 1, the difference is that the molar ratio of carrier to fluorocarbon compound is 1:1, and other process steps and dosages are completely consistent with Example 1.

[0115] Comparative Example 4

[0116] On the basis of Example 1, the difference is that the molar ratio of carrier to fluorocarbon compound is 1:5, and other process steps and dosages are completely consistent with Example 1.

[0117] Table 1

[0118]

[0119] V. Product application

[0120] Directly purchase 1 L of each of commercial-grade fluoropolymer emulsions containing PFOA, PFOS, GenX, and PFPE.

[0121] Example 12

[0122] (1) Capture experiment

[0123] Take 15 mL of fluoropolymer emulsion containing PFOA and place it in 5 20 mL sample bottles, add different mass (0.02 g, 0.03 g, 0.04 g, 0.05 g, 0.06 g) of PP fibers prepared in Example 1, adsorb for 3 h at 25°C, after adsorption is completed, take 5 mL of emulsion and add ethanol to break it, then centrifugal separation, take 1 mL of supernatant and filter with 0.22 μm needle filter, then test with LC-MS / MS, the removal rate for PFOA is 70.65%, 80.23%, 89.87%, 92.36%, 96.84% respectively, as shown in Figure 6 .

[0124] Example 13

[0125] (1) Capture experiment

[0126] Take 15 mL of fluoropolymer emulsion containing PFOA and place it in 5 20 mL sample bottles, add different mass (0.02 g, 0.03 g, 0.04 g, 0.05 g, 0.06 g) of PP fibers prepared in Example 2, adsorb for 3 h at 25°C, after adsorption is completed, take 5 mL of emulsion and add ethanol to break it, then centrifugal separation, take 1 mL of supernatant and filter with 0.22 μm needle filter, then test with LC-MS / MS, the removal rate for PFOA is 73.21%, 86.69%, 90.63%, 94.14%, 99.98% respectively, as shown in Figure 7 .

[0127] Example 14

[0128] (1) Capture experiment

[0129] Take 15 mL of fluoropolymer emulsion containing PFOA and place it in 5 20 mL sample bottles, add different mass (0.02 g, 0.03 g, 0.04 g, 0.05 g, 0.06 g) of PP fibers prepared in Example 3, adsorb for 3 h at 25°C, after adsorption is completed, take 5 mL of emulsion and add ethanol to break it, then centrifugal separation, take 1 mL of supernatant and filter with 0.22 μm needle filter, then test with LC-MS / MS, the removal rate for PFOA is 72.36%, 81.51%, 92.1%, 95.32%, 98.64% respectively, as shown in Figure 8 .

[0130] Example 15

[0131] (1) Capture experiment

[0132] Take 15 mL of fluoropolymer emulsion containing PFOA and place it in 5 20 mL sample bottles, respectively, add different mass 0.06 g of PP fiber prepared in Example 2, adsorb for 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h respectively at 25 ℃, after adsorption is completed, take 5 mL emulsion and add ethanol to break the emulsion, then centrifugal separation, take 1 mL supernatant and filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rate of PFOA is calculated as 60.42%, 82.63%, 90.21, 95.78%, 97.58%, 99% respectively, as shown in Figure 9 .

[0133] Example 16

[0134] (1) Capture experiment

[0135] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 1 respectively, adsorb for 3 h at 25 ℃, after adsorption is completed, take 5 mL emulsion and add ethanol to break the emulsion, then centrifugal separation, take 1 mL supernatant and filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rate is calculated as 98.1%, 98.4%, 99.2%, 99.1% respectively.

[0136] Example 17

[0137] (1) Capture experiment

[0138] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 2 respectively, adsorb for 3 h at 25 ℃, after adsorption is completed, take 5 mL emulsion and add ethanol to break the emulsion, then centrifugal separation, take 1 mL supernatant and filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rate is calculated as 98.0%, 99.1%, 99.5%, 99.8% respectively.

[0139] Example 18

[0140] (1) Capture experiment

[0141] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 3 respectively, adsorb at 25 ℃ for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rate is calculated as 99.2%, 99.4%, 99.6%, 99.9% respectively.

[0142] Example 19

[0143] (1) Capture experiment

[0144] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 4 respectively, adsorb at 25 ℃ for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rate is calculated as 94.3%, 95.6%, 93.1%, 93.7% respectively.

[0145] Example 20

[0146] (1) Capture experiment

[0147] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 5 respectively, adsorb at 25 ℃ for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rate is calculated as 95.4%, 96.5%, 96.3%, 97.4% respectively.

[0148] Example 21

[0149] (1) Capture experiment

[0150] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 6 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rates are calculated as 96.0%, 98.5%, 97.0%, 98.1% respectively.

[0151] Example 22

[0152] (1) Capture experiment

[0153] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 7 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rates are calculated as 99.0%, 95.5%, 98.3%, 96.8% respectively.

[0154] Example 23

[0155] (1) Capture experiment

[0156] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 8 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rates are calculated as 93.2%, 98.5%, 95.3%, 98.8% respectively.

[0157] Example 24

[0158] (1) Capture experiment

[0159] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 9 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rates are calculated as 87.2%, 88.5%, 91.3%, 88.8% respectively.

[0160] Example 25

[0161] (1) Capture experiment

[0162] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Example 10 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rates are calculated as 95.3%, 96.5%, 97.3%, 97.8% respectively.

[0163] Example 26

[0164] (1) Capture experiment

[0165] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of polyacrylonitrile fiber prepared in Example 11 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle type filter, then test with LC-MS / MS, the removal rates are calculated as 94.1%, 93.8%, 95.3%, 96.9% respectively.

[0166] Example 27

[0167] (1) Capture experiment

[0168] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Comparative Example 1 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifuge, take 1 mL of supernatant, filter with a 0.22 μm canning needle filter, then test with LC-MS / MS, and the removal rates are calculated to be 81.0%, 84.1%, 84.3%, and 83.9% respectively.

[0169] Example 28

[0170] (1) Capture experiment

[0171] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Comparative Example 1 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifuge, take 1 mL of supernatant, filter with a 0.22 μm canning needle filter, then test with LC-MS / MS, and the removal rates are calculated to be 81.0%, 84.1%, 84.3%, and 83.9% respectively.

[0172] Example 29

[0173] (1) Capture experiment

[0174] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then place them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Comparative Example 1 respectively, adsorb at 25°C for 3 h, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifuge, take 1 mL of supernatant, filter with a 0.22 μm canning needle filter, then test with LC-MS / MS, and the removal rates are calculated to be 81.0%, 84.1%, 84.3%, and 83.9% respectively.

[0175] Example 30

[0176] (1) Capture experiment

[0177] Take 15 mL of fluoropolymer emulsion containing PFOA, PFOS, GenX, PFPE respectively, then put them in 4 20 mL sample bottles respectively, add 0.06 g of PP fiber prepared in Comparative Example 4 respectively, adsorb for 3 h at 25 ℃, after adsorption is completed, take 5 mL of emulsion, add ethanol to break the emulsion, then centrifugal separation, take 1 mL of supernatant, filter with 0.22 μm needle filter, then test with LC-MS / MS, the removal rates are 93.0%, 94.1%, 90.3%, 95.9% respectively.

[0178] The detection results of Examples 12-14 are shown in Table 2.

[0179] Table 2 Removal results of different amounts of grafted PP fibers on PFOA in fluoropolymer emulsion

[0180] Serial number Use of capture material The PFOA removal rates of different amounts of PP fiber were in the order of Example 12 Synthesized from Example 1 70.65％、80.23％、89.87％、92.36％、96.84％ Example 13 Synthesized from Example 2 73.21％、86.69％、90.63％、94.14％、99.98％ Example 14 Synthesized from Example 3 72.36％、81.51％、92.1％、95.32％、98.64％

[0181] Table 3 Removal results of different adsorption times on PFOA in fluoropolymer emulsion

[0182] Serial number Use of capture material The PFOA removal rates of different capture times were in the order of Example 15 Synthesized from Example 2 60.42％、82.63％、90.21、95.78％、97.58％、99％

[0183] The detection results of Examples 16-30 are shown in Table 4.

[0184] Table 4 Removal results of different modifiers grafted PP fibers on different fluorocarbon surfactants

[0185] Use of capture material The PFOA, PFOS, GenX, PFPE removal rates were in the order of Example 16 Synthesized from Example 1 98.1％、98.4％、99.2％、99.1％ Example 17 Synthesized from Example 2 98.0％、99.1％、99.5％、99.8％ Example 18 Synthesized from Example 3 99.2％、99.4％、99.6％、99.9％ Example 19 Synthesized from Example 4 94.3％、95.6％、93.1％、93.7％ Example 20 Synthesized from Example 5 95.4％、96.5％、96.3％、97.4％ Example 21 Synthesized from Example 6 96.0％、98.5％、97.0％、98.1％ Example 22 Synthesized from Example 7 99.0％、95.5％、98.3％、96.8％ Example 23 Synthesized from Example 8 93.2％、98.5％、95.3％、98.8％ Example 24 Synthesized from Example 9 87.2％、88.5％、91.3％、88.8％ Example 25 Synthesized from Example 10 95.3％、96.5％、97.3％、97.8％ Example 26 Synthesized from Example 11 94.1％、93.8％、95.3％、96.9％ Example 27 Synthesized from Comparative Example 1 81.0％、84.1％、84.3％、83.9％ Example 28 Synthesized from Comparative Example 2 68.0％、69.1％、70.6％、65.9％ Example 29 Synthesized from Comparative Example 3 78.0％、69.1％、70.3％、75.9％ Example 30 Synthesized from Comparative Example 4 93.0％、94.1％、90.3％、95.9％

[0186] Taking PFOA as an example, the removal rates of PFOA in fluoropolymer emulsion by the capture materials synthesized in the examples and comparative examples are obviously different:

[0187] (1) As shown in Table 4, the capture materials described in the application can achieve a removal rate of more than 87% on PFAS in fluoropolymer emulsion, and the highest can be more than 99%, using fluorocarbon compounds with a chain length of more than 6 and having double bonds or mercapto compounds in the examples. Figure 3 、 6 As shown in the table, the removal rate increases with the increase of the amount of capture PP fiber and the capture time, and almost reaches the highest removal rate after 0.06 g, 3 h; at the same time, the capture materials prepared in the examples maintain the stable emulsification state of the emulsion during the entire adsorption process, and no demulsification phenomenon occurs, and the emulsion still maintains the emulsification state after the capture materials are taken out after the adsorption is completed, and the difference between the emulsification state and the emulsion before the adsorption is not large, so it can be seen that the capture materials described in the application will not destroy the stability of the fluoropolymer emulsion when adsorbing the fluorocarbon surfactant in the fluoropolymer emulsion.

[0188] (2) Example 11 used polyacrylonitrile fiber as a carrier. Compared with the example using PP fiber as a carrier, it can be seen that the removal rates of fluorocarbon surfactants PFAS are not significantly different. At the same time, the present invention also conducted experiments on polyethylene fiber, polyolefin fiber, polyvinyl alcohol formal fiber, and polyvinyl chloride fiber as carriers. All of these carriers can achieve the technical effects described in the present invention. However, some other types of fibers, such as cotton fiber, have poor activation and grafting effects, and their removal rates of fluorocarbon surfactants are even lower than those in the comparative examples of the present invention. Some fibers even failed to graft successfully, so they were not included in the comparative examples. It can be seen that among the carriers used in the present invention, the removal efficiency of PFAS by the capture materials prepared by different carriers is not significantly different.

[0189] (3) In Comparative Example 1, a short fluorocarbon chain compound with a fluorocarbon chain length of less than 6 was used. This short fluorocarbon chain compound was perfluoromethanethiol. The adsorption efficiency of the capture material synthesized in this way for PFAS was much lower than that in the example. It can be seen that the short fluorocarbon chain compound is not ideal for removing long fluorocarbon chain compounds in fluoropolymer emulsions. This also shows that the capture material made of short fluorocarbon chain compound is difficult to remove long fluorocarbon chain compounds in fluoropolymer emulsions. At the same time, even though the examples all grafted long fluorocarbon chain compounds with a fluorocarbon chain length of more than 6, the removal effects of different long fluorocarbon chain compounds on different long fluorocarbon surfactants are also different.

[0190] (4) In Comparative Example 2, trialkylaluminum-titanium trichloride was used as a catalyst. Although it could also activate the surface of the carrier, the activation effect was significantly less than that of the initiator. The removal rate of the captured fiber was significantly lower than that of the plasma treatment, initiator, and irradiation methods in the examples. Comparative Examples 3 and 4 were grafted in different proportions. It can be seen that when the amount of fluorocarbon compound was small, the grafting rate was low and the removal rate decreased significantly. When the amount of fluorocarbon compound was too large, the removal rate did not increase proportionally and even decreased. Therefore, further increasing the amount of fluorocarbon compound did not have a positive effect on the adsorption effect of the captured material.

[0191] (5) As can be seen from the data in the above embodiments, the capture material prepared by grafting different types of fluorocarbon chains and using plasma treatment, initiators, and irradiation has a high removal rate of PFAS in fluoropolymer emulsions. Therefore, the capture material for removing fluorocarbon surfactants from fluoropolymer emulsions prepared in this invention has a good removal effect on PFOA, PFOS, GenX, and PFPE, and the use of PP fiber as the capture material can achieve rapid separation from the fluoropolymer emulsion.

[0192] Finally, it needs to be explained that the above examples are only used to illustrate the technical solutions of the present application but not to limit the technical solutions, and those of ordinary skill in the art should understand that the technical solutions of the present application are modified or equivalently replaced without departing from the purpose and scope of the technical solutions, which should be covered in the scope of claims of the present application.

Claims

1. A capture material for removing fluorocarbon surfactant from a fluoropolymer emulsion, characterized by, The capture material is a material with fluorocarbon compound grafted on the surface of a carrier; wherein the carrier is one of PP fiber, polyacrylonitrile fiber, polyethylene fiber, polyvinyl formal fiber and polyvinyl chloride fiber; the fluorocarbon compound is a fluorocarbon compound with carbon chain length of at least 6 and at least one of carbon-carbon double bond, mercapto group, aldehyde group, carbonyl group, carboxyl group and nitrogen-containing active group; The fluorocarbon compound includes one of perfluorohexyl ethylene, perfluorooctyl ethylene, perfluorodecyl ethyl acrylate, perfluorohexyl ethanethiol, perfluorooctyl ethanethiol, perfluorodecyl ethanethiol, perfluorooctyl aldehyde, perfluorohexanone and perfluorohexanoic acid; The preparation method of the capture material includes the following steps: Step 1: activating the surface of the carrier to form free radicals on the surface of the carrier; Step 2: grafting the carrier after step 1 with the fluorocarbon compound to obtain the capture material; wherein the grafting process is a reaction at 50-80 ℃ for more than 6 hours; the molar ratio of the carrier to the fluorocarbon compound is at least 1:2; In step 1, the carrier is treated by one of plasma treatment, initiator or irradiation to produce free radicals on the surface of the carrier.

2. The capture material of claim 1, wherein, When the carrier is treated by plasma, the carrier is treated by the plasma machine for more than 200 seconds.

3. The capture material of claim 1, wherein, When the carrier is treated by initiator, peroxide or azo compound is selected as the initiator; the mass ratio of the initiator to the carrier is 1:(4-6); the initiator is one of dibenzoyl peroxide and azobisisobutyronitrile.

4. The capture material of claim 1, wherein, When the support is treated by irradiation, the support is placed under a 60 Coy radiation source for at least 12 h.

5. Use of a capture material for removing fluorocarbon surfactants from a fluoropolymer emulsion, characterized in that, The capture material of any one of claims 1-4 is used for removing fluorocarbon surfactant in fluoropolymer emulsion.

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