Patent Application
20240307863
Disclosed herein are compositions that include styrenic fluoropolymers. In one specific embodiment, the styrenic fluoropolymers can be made by contacting a styrene substituted perfluoropolyether with triphenyl-4-vinyl benzyl phosphonium chloride. In another specific embodiment, the styrenic fluoropolymers can be used as an anionic exchange resin to separate perfluoro alkyl and polyfluoro alkyl (PFAS) substances from mixtures.
Perfluoro alkyl and polyfluoro alkyl (PFAS) substances are a class of man-made compounds that are used to manufacture consumer products and industrial chemicals. PFAS are used as surfactants and surface coatings in consumer products, such as fire-fighting foams, non-stick cookware, textiles, carpet, paper, upholstery, packaging, and lubricants. The utility of PFAS is due to their exceptional stability and favorable physicochemical properties. However, the characteristics that make PFAS beneficial for these applications can also prevent them from readily degrading in the environment and make them challenging to remediate. For example, PFAS have carbon-fluorine bonds, which among the strongest bonds in nature and are resistant to breakdown. Temperatures above 600° C., are necessary to effectively breakdown certain PFAS compounds. Additionally, PFAS are highly water soluble and have low volatility, which can result in large, dilute plumes if they are released into the environment.
Toxicity concerns of PFAS in human and living systems due to their bioaccumulation are well-known. These risks include cancer, estrogen disruption, protein misfolding, immune deficiency, neurotoxicity, and birth defects. For example, laboratory PFAS exposure studies on animals have shown problems with growth and development, reproduction, and liver damage. In 2016, the U.S. Environmental Protection Agency (EPA) issued the following health advisories (HAs) for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA): 0.07 μg/L for both the individual constituents and the sum of PFOS and PFOA concentrations, respectively. However, current water treatment systems and methods to remove PFAS from water have limited effectiveness. For example, activated carbon adsorption systems and methods to remove PFAS from water have shown to be somewhat effective on the longer chain PFAS, but have difficulty in removing branched and shorter chain compounds. Other conventional methods have been tried, such as biological treatment, air stripping, reverse osmosis, and advanced oxidation; however, these techniques also have limited abilities at removing PFAS from water.
Consequently, there is need for new compositions that can be used for the selective separation of PFAS from mixtures and the environment.
Disclosed herein are styrenic fluoropolymers of a Formula 1:
In a specific embodiment, a method of making styrenic fluoropolymers can include contacting a perfluoropolyether-diol of Formula 2:
HO—(CH2CH2O)s—CH2—CF2—O—(CF2—CF2O)t—(CF2))v—CF2—CH2—O—(CH2—CH2O)w—OH Formula 2
where, s, t, v, and w are independently selected from an integer from 1 to 1000, with a 4-vinyl benzyl chloride to make a styrene substituted perfluoropolyether of Formula 3:
wherein, s, t, v, and w are independently selected from an integer from 1 to 1000.
The method can further include contacting triphenyl phosphene with 4-vinyl benzyl chloride to make a triphenyl-4-vinyl benzyl phosphonium chloride. Then, contacting the triphenyl-4-vinyl benzyl phosphonium chloride with the styrene substituted perfluoropolyether of Formula 3 to make a styrenic fluoropolymer comprising a Formula 1.
In another specific embodiment, a method for at least partially removing perfluoroalkyl or poly fluoroalkyl substances from a mixture can include contacting a mixture containing one or more perfluoroalkyl or polyfluoroalkyl substances with a styrenic fluoropolymers of Formula 1 and separating the styrenic fluoropolymer from the mixture after the content of the one or more perfluoroalkyl or poly fluoroalkyl substances has been reduced.
The present disclosure can be better understood by referring to the following drawings. The drawings constitute a part of this specification and include exemplary embodiments of the styrenic fluoropolymers, which may be embodied in various forms.
Per- and polyfluoroalkyl substances (PFAS) and their high molecular weight polymer analogs (e.g., polytetrafluoroethylene) are also dubbed as “Forever Chemicals” due to their exceptional stability imparted by strong C—F bonds and these fluorinated surfactants possess excellent physicochemical properties for their use in consumer products.1-8 For example, surfactant-like characteristics of PFAS coatings containing PFOA and PFOS have enabled their growing utilization in common consumer goods (e.g., nonstick cookware, grease-resistant food packaging, waterproof clothing, carpet, fire-fighting foams, lubricants, etc.) that make up our everyday life. This has unfortunately led to their continuous disposal into the environment posing serious remediation challenges.9,10 Toxicity concerns of synthetic PFAS in human and living systems due to their bioaccumulation are well-documented which included cancer, 11 estrogen disruption, 12 protein misfolding,13 birth defects in children, 14,15 and other health risks in humans.16-18 These challenges have incited renewed interests in the investigation of PFAS for sensing,19,20 separation21-25 and destructive sequestration technologies.26-31 Among this large family of PFAS compounds, US EPA has set health advisory limit of 70 ng/L for the total concentration of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in drinking water32,33 while European health commission has set the health advisory limit of about 100-500 ng/L of these combined PFAS in drinking water.34,35
Traditionally most common separation methods for removing PFAS involve the use of granular activated carbon.36-38 ion exchange resins38,39 and inorganic materials40-42 which however suffer from modest treatment volumes before saturation, low affinity for long- and short chain PFASs and limited selectivity for PFASs because of strong adsorption affinity for other organic or inorganic co-contaminants in water. These limitations motivated researchers to design novel adsorbents such as cross-linked b-cyclodextrin polymers.43-45 ionic fluorogels.22,46-48 metal-organic frameworks49,50 and covalent organic frameworks23,51 in remediation of PFAS. Among most notable works, cross-linked b-cyclodextrin based polymers containing tetra alkyl ammonium cations demonstrated highly efficient removal of PFAS at ultralow concentrations.43-45 However, in addition to expensive cross-linkers, limited selectivity is observed in the presence of other organic micropollutants/drugs considering the hydrophobic cavity of b-cyclodextrin based polymers which are also widely employed as a drug carrier to deliver hydrophobic drugs into cells.43 To address selective PFAS removal from waters. Kumarasamy et.al reported the design of ionic fluorogels composed of alkyl ammonium bearing perfluoropolyether backbone with methacrylate chain-end functionality which showed excellent selectivity in the removal of a wide range of PFASs mixture from deionized and river waters.22 However, the presence of the ester groups at the methacrylate chain ends in the polymers is susceptible to nucleophilic attack enabling the potential polymer degradation in a basic environment and in the presence of strong nucleophiles.22 In addition, it is postulated that phosphonium based organic cations possess excellent thermal stability and ionic conductivity in reference to their corresponding alkyl ammonium counterparts considering the larger size and lower electronegativity of the central phosphorous atom. P bearing cations in reference to the central nitrogen atom. N bearing cation moieties.52,53 Therefore, the objective of ionic fluoropolymer design is to introduce highly stable polystyrene functionality into the polymer backbone along with phosphonium cations to impart much higher performance and durability of fluoropolymer in selective removal of perfluoroalkyl species from diverse water matrices including real environmental water matrices.
Using design concepts of electrostatic and selective fluorophilic interactions C—F - - - F—C, rational design and application of styrene incorporated anion exchange fluoropolymer bearing phosphonium cations for selective separation of perfluoroalkyl substances (e.g., PFOA, PFOS, etc.) from waters at sub-ppb levels have been made. This molecular design is achieved by leveraging fundamental principles of electrostatic interactions for targeted anion exchange with the ionic fluoropolymer which is facilitated by favorable non-covalent forces of interactions with fluorophilic groups in the polymer backbone. A class of quaternary tetra-aryl phosphonium bearing styrene based perfluorinated anion exchange polymer is synthesized via multi-step nucleophilic substitution reactions of di-alcohol terminated perfluoropolyether compound in presence of sodium hydride and 4-vinyl benzyl chloride to incorporate styrene functionality at the chain end to impart critical stability. This is followed by a thermally induced radical copolymerization reaction between the styrene functionalized perfluorinated monomer with triphenyl 4-vinyl benzyl phosphonium chloride monomer prepared separately and AIBN to obtain the styrene-based crosslinked ionic fluoropolymer network prepared in the chloride form. The obtained fluoropolymer is structurally characterized and confirmed using NMR, IR spectroscopy and MALDI spectrometry analyses. The polymer is demonstrated for the treatment of model PFAS compounds (e.g., PFOA and PFOS) in their removal from water at both high (mM) and ultralow concentrations (mg/L) in different water matrices and lake water containing various inorganic constituents and dissolved organic co-contaminants like phenols. The results revealed that fluoropolymer selectively removes PFOA and PFOS with excellent removal efficiency (>90% removal efficiency) through irreversible anion exchange aided by strong van der Waal forces of interaction with fluorine rich backbone of the polymer. The selectivity of ionic fluoropolymer is further delineated using phenol as a model organic contaminant in water by employing pure hydrocarbon-based ionic polymer without fluorophilic component and neutral perfluoropolyether compound. This study highlighted the requirement for anion-exchange sites (prepared in chloride form) within perfluorinated backbones and side chains with quaternary phosphonium groups to promote the anion exchange process for PFOA or PFOS anions which is further assisted by favorable non-covalent interactions between the fluorophilic groups of the polymer and the perfluorinated anionic species (PFOA and PFOS) in water.
The styrenic fluoropolymers can include compounds of Formula 1:
The styrenic fluoropolymers can have a weight-average molar mass (Mw) that varies widely. For example, the styrenic fluoropolymers can have a weight-average molar mass from a low of about 300 g/mol, about 3,000 g/mol, or about 10,000 g/mol, to a high of about 80,000 g/mol, about 100,000 g/mol, or about 200,000 g/mol. In another example, styrenic fluoropolymers can have a weight-average molecular weight that is less than 8,000 g/mol, less than 5,000 g/mol, or less than 1,000 g/mol. In another example, the styrenic fluoropolymers can have a weight-average molar mass from about 300 g/mol to about 200,000 g/mol, about 300 g/mol to about 1,200 g/mol, about 1,000 g/mol to about 10,000 g/mol, about 2,000 g/mol to about 50,000 g/mol, about 100,000 g/mol to about 200,000 g/mol. The molar mass of the styrenic fluoropolymers can be measured by gel permeation chromatography with tri-detectors.
The styrenic fluoropolymers can have a number-average molar mass (Mn) that varies widely. For example, the styrenic fluoropolymers can have a number-average molar mass from a low of about 300 g/mol, about 1,000 g/mol, or about 3,000 g/mol, to a high of about 80,000 g/mol, about 100,000 g/mol, or about 200,000 g/mol. In another example, styrenic fluoropolymers can have a number-average molar mass that is less than 500 g/mol, less than 6,000 g/mol, or less than 10,000 g/mol. In another example, the styrenic fluoropolymers can have a number-average molar mass from about 300 g/mol to about 2,000 g/mol, about 3,000 g/mol to about 20,000 g/mol, about 2,000 g/mol to about 8,000 g/mol, about 40,000 g/mol to about 80,000 g/mol, about 100,000 g/mol to about 200,000 g/mol.
The styrenic fluoropolymers of Formula 1 can be used as an anion exchange resin for at least partial and selective removal of PFAS substances by leveraging fundamental concepts of ionic and non-covalent interactions. The styrenic fluoropolymers can include, but are not limited to, a quaternary tetra aryl phosphonium bearing styrene substituted fluorinated anion exchange resin. The structural characteristics with crosslinked polystyrene network containing phosphonium ion units can be superior in terms of polymer stability and PFAS removal efficiency in reference to other counterparts containing tetra-alkyl ammonium units in a fluorinated polymer. For example, the styrenic fluoropolymer can have a removal efficiency of greater than 80% of perfluorooctanoic acid and perfluorooctane sulfonic acid at environmentally relevant concentrations.
In an embodiment, the synthesis of the styrenic fluoropolymers can include, but is not limited to: a first reaction for the synthesis of styrene functionalized perfluorinated monomer,
and
The subscripts m and n can be an integer greater than 1, greater than 2, greater than 5, greater than 10, greater than 20, greater than 50, greater than 100, greater than 200, or greater than 500. For example subscripts m and n can be independently selected from an integer in the range of 1 to 1,000, 1 to 800, 1 to 600, 1 to 500, 1 to 200, 1 to 100, 10 to 100, 15 to 80, 20 to 200, 17 to 50, 34 to 112, 9 to 46, or 5 to 20.
In another embodiment, the synthesis of the styrenic fluoropolymers can include, but is not limited to: a reaction scheme depicted in
A wide range of equivalents of 4-vinyl benzyl chloride can be used to contact one equivalent of perfluoropolyether-diol of Formula 1. For example, a low of about 0.5 equivalents, about 1 equivalent, about 1.5 equivalents of 4-vinyl benzyl chloride can be contacted with one equivalent of perfluoropolyether-diol of Formula 1, to a high of about 5 equivalents, 10 equivalents or about 50 equivalents of 4-vinyl benzyl chloride can be contacted with one equivalent of perfluoropolyether-diol of Formula 1. In another example, about 0.5 equivalents to about 1 equivalent of 4-vinyl benzyl chloride can be contacted with one equivalent of perfluoropolyether-diol of Formula 1, about 1 equivalents to about 2 equivalent of 4-vinyl benzyl chloride can be contacted with one equivalent of perfluoropolyether-diol of Formula 1, about 2 equivalents to about 2.5 equivalent of 4-vinyl benzyl chloride can be contacted with one equivalent of perfluoropolyether-diol of Formula 1, or about 2.2 equivalents to about 3 equivalents of 4-vinyl benzyl chloride can be contacted with one equivalent of perfluoropolyether-diol of Formula 1.
A wide range of molar ratios of 4-vinyl benzyl chloride can be contacted 1 mol of perfluoropolyether-diol of Formula 1. For example, a low of about 0.5 mols, about 1 mol, or about 1.5 moles of 4-vinyl benzyl chloride can be contacted with 1 mol of perfluoropolyether-diol of Formula 1, to a high of about 5 mols, 10 mols or about 50 mols of 4-vinyl benzyl chloride can be contacted with 1 mol of perfluoropolyether-diol of Formula 1. In another example, about 0.5 mols to about 1 mol of 4-vinyl benzyl chloride can be contacted with 1 mol of perfluoropolyether-diol of Formula 1, about 1 mol to about 2 moles of 4-vinyl benzyl chloride can be contacted with 1 mole of perfluoropolyether-diol of Formula 1, about 2 mols to about 2.5 mols of 4-vinyl benzyl chloride can be contacted with 1 mol of perfluoropolyether-diol of Formula 1, or about 2.2 mols to about 3 mols of 4-vinyl benzyl chloride can be contacted with 1 mol of perfluoropolyether-diol of Formula 1.
Perfluoropolyether-diol of Formula 1 can be added to Mixture 1 in a weight percent from about 10 wt % to about 90 wt %, based on the total weight of Mixture 1 or based on the total weight perfluoropolyether-diol of Formula 1, 4-vinyl benzyl chloride, base, and solvent.
4-Vinyl benzyl chloride can be added to Mixture 1 in a weight percent of about from about 10 wt % to about 90 wt %, based on the total weight of Mixture 1 or based on the total weight perfluoropolyether-diol of Formula 1, 4-vinyl benzyl chloride, base, and solvent.
The solvents for Mixture 1 can include, but is not limited to: acetic acid, acetone, acetonitrile, benzene, 1-butanol, 2-butanol, 2-butanone, t-butyl alcohol, carbon tetrachloride, chlorobenzene, chloroform, cyclohexane, 1,2-dichloroethane diethylene glycol diethyl ether, diglyme diethylene glycol dimethyl ether), N,N-dimethylformamide (DMF), 1,2-dimethoxy-ethane (glyme, DME), dimethyl sulfoxide (DMSO), 1,4-dioxane, ethanol, ethyl acetate, ethylene glycol, glycerin, heptane, hexamethylphosphoramide (HMPA), hexamethylphosphorous triamide (HMPT), hexane, methanol, methyl t-butyl ether (MTBE), methylene chloride, N-methyl-2-pyrrolidinone (NMP), nitromethane, pentane, petroleum ether (ligroine), 1-propanol, 2-propanol, pyridine, tetrahydrofuran (THF), toluene, triethyl amine, triethyl amine, water, o-xylene, m-xylene, and p-xylene.
The base of Mixture 1 can include, but is not limited to, sodium hydride, ethoxide ion, butyl lithium (n-BuLi), lithium diisopropylamide (C6H14LiN), lithium diethylamide (LDEA), sodium amide (NaNH2), sodium hydride (NaH), lithium bis(trimethylsilyl)amide, ((CH3)3Si)2NLi, lithium hydroxide (LiOH), (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), calcium hydroxide (Ca(OH)2), strontium hydroxide Sr(OH)2, and barium hydroxide (Ba(OH)2).
Reaction 1 or Mixture 1 can be heated to a temperature from a low of about 0° C., about 15° C., and about 25° C., to a high of about 35° C., about 65° C., and about 100° C. For example, Mixture 1 can be heated to a temperature between about 25° C., to about 28° C., 25° C. to about 35° C., or 30° C., to about 45° C., 43° C., to about 78° C. In another example, Mixture 1 can be at room temperature.
Reaction 1 or Mixture 1 can be reacted and/or stirred for a Reaction Time 1. Reaction Time 1 can be from a short of about 15 s, about 120 s, or about 300 s, to a long of about 24 h, about 96 h, or about 1 one week. For example, Reaction Time 1 can be from about 1 min to about 15 min, about 5 min to about 45 min, about 60 min to about 2 h, about 35 min to about 80 h, about 1 h to about 5 h, about 5 h to about 50 h, about 1 min to about 15 min, about 24 h to about 96 h, and about 40 h to about 1 week.
Reaction 1 or Mixture 1 can be reacted and/or stirred in an open reaction container or a closed container. Reaction 1 or Mixture 1 can be reacted and/or stirred under a vacuum. Reaction 1 or Mixture 1 can be reacted and/or stirred under an inert atmosphere, such as He, Ne, Ar, N2, Ar.
In an embodiment, the method of making a styrenic fluoropolymer can further include contacting triphenyl phosphene, PPh3, with 4-vinyl benzyl chloride to make a triphenyl-4-vinyl benzyl phosphonium chloride in a Reaction 2. The triphenyl phosphene, PPh3, can be contacted with 4-vinyl benzyl chloride in a Mixture 2. Mixture 2 can also include, but is not limited to, a base and a solvent.
A wide range of equivalents of triphenyl phosphene can be used to contact one equivalent of 4-vinyl benzyl chloride. For example, a low of about 0.5 equivalents, about 1 equivalent, about 1.5 equivalents of triphenyl phosphene can be contacted with one equivalent of 4-vinyl benzyl chloride, to a high of about 5 equivalents, 10 equivalents or about 50 equivalents of triphenyl phosphene can be contacted with one equivalent of 4-vinyl benzyl chloride. In another example, about 0.5 equivalents to about 1 equivalent of triphenyl phosphene can be contacted with one equivalent of 4-vinyl benzyl chloride, about 1 equivalents to about 2 equivalent of triphenyl phosphene can be contacted with one equivalent of 4-vinyl benzyl chloride, about 2 equivalents to about 2.5 equivalent of triphenyl phosphene can be contacted with one equivalent of 4-vinyl benzyl chloride, or about 2.2 equivalents to about 3 equivalent of triphenyl phosphene can be contacted with one equivalent of 4-vinyl benzyl chloride.
A wide range of molar ratios of triphenyl phosphene can be contacted 1 mol of 4-vinyl benzyl chloride. For example, a low of about 0.5 mols, about 1 mol, or about 1.5 moles of triphenyl phosphene can be contacted with 1 mol of 4-vinyl benzyl chloride, to a high of about 5 mols, 10 mols or about 50 mols of triphenyl phosphene can be contacted with 1 mol of 4-vinyl benzyl chloride. In another example, about 0.5 mols to about 1 mol of triphenyl phosphene can be contacted with 1 mol of 4-vinyl benzyl chloride, about 1 mol to about 2 moles of triphenyl phosphene can be contacted with 1 mole of 4-vinyl benzyl chloride, about 2 mols to about 2.5 mols of triphenyl phosphene can be contacted with 1 mol of 4-vinyl benzyl chloride, or about 2.2 mols to about 3 mols of triphenyl phosphene can be contacted with 1 mol of 4-vinyl benzyl chloride.
The triphenyl phosphene can be added to Mixture 2 in a weight percent from about 10 wt % to about 90 wt %, based on the total weight of Mixture 2 or based on the total weight triphenyl phosphene, 4-vinyl benzyl chloride, base, and solvent.
The 4-vinyl benzyl chloride can be added to Mixture 2 in a weight percent of from about 10 wt % to about 90 wt %, based on the total weight of Mixture 2 or based on the total weight triphenyl phosphene, 4-vinyl benzyl chloride, base, and solvent.
The solvents for Mixture 2 can include, but is not limited to: acetic acid, acetone, acetonitrile, benzene, 1-butanol, 2-butanol, 2-butanone, t-butyl alcohol, carbon tetrachloride, chlorobenzene, chloroform, cyclohexane, 1,2-dichloroethane diethylene glycol diethyl ether, diglyme diethylene glycol dimethyl ether, N,N-dimethylformamide, 1,2-dimethoxy-ethane, dimethyl sulfoxide, 1,4-dioxane, ethanol, ethyl acetate, ethylene glycol, glycerin, heptane, hexamethylphosphoramide, hexamethylphosphorous triamide, hexane, methanol, methyl t-butyl ether, methylene chloride, N-methyl-2-pyrrolidinone, nitromethane, pentane, petroleum ether, 1-propanol, 2-propanol, pyridine, tetrahydrofuran, toluene, triethyl amine, triethyl amine, water, o-xylene, m-xylene, and p-xylene.
Reaction 2 or Mixture 2 can be heated to a temperature from a low of about 0° C., about 15° C., and about 25° C., to a high of about 35° C., about 65° C., and about 100° C. For example, Mixture 2 can be at room temperature. In another example, Mixture 2 can be heated to a temperature between about 25° C., to about 28° C., 25° C., to about 35° C., or 30° C., to about 45° C., 43° C., to about 78° C.
Reaction 2 or Mixture 2 can be reacted and/or stirred for a Reaction Time 2. Reaction Time 2 can be from a short of about 15 s, about 120 s, or about 300 s, to a long of about 24 h, about 96 h, or about 1 one week. For example, Reaction Time 2 can be from about 1 min to about 15 min, about 5 min to about 45 min, about 60 min to about 2 h, about 35 min to about 80 h, about 1 h to about 5 h, about 5 h to about 50 h, about 1 min to about 15 min, about 24 h to about 96 h, and about 40 h to about 1 week.
Reaction 2 or Mixture 2 can be reacted and/or stirred in an open reaction container or a closed container. Reaction 2 or Mixture 2 can be reacted and/or stirred under a vacuum. Reaction 2 or Mixture 2 can be reacted and/or stirred under an inert atmosphere, such as He, Ne, Ar, N2, Ar.
In an embodiment, the method of making a styrenic fluoropolymer of Formula 1 can further include contacting styrene substituted perfluoropolyether of Formula 2 with the triphenyl-4-vinyl benzyl phosphonium chloride to make a styrenic fluoropolymer of Formula 1 in a Reaction 3. The styrene substituted perfluoropolyether of Formula 2 can be contacted with the triphenyl-4-vinyl benzyl phosphonium chloride in a Mixture 3. Mixture 3 can also include, but is not limited to, a radical initiator and a solvent.
A wide range of molar ratios of styrene substituted perfluoropolyether of Formula 2 can be contacted 1 mol of triphenyl-4-vinyl benzyl phosphonium chloride. For example, a low of about 1 mol, about 5 mol, or about 10 moles of styrene substituted perfluoropolyether of Formula 2 can be contacted with 1 mol of triphenyl-4-vinyl benzyl phosphonium chloride, to a high of about 50 mols, 100 mols or about 500 mols of styrene substituted perfluoropolyether of Formula 2 can be contacted with 1 mol of 4 triphenyl-4-vinyl benzyl phosphonium chloride. In another example, about 0.5 mols to about 1 mol of styrene substituted perfluoropolyether of Formula 2 can be contacted with 1 mol of triphenyl-4-vinyl benzyl phosphonium chloride, about 1 mol to about 2 moles of styrene substituted perfluoropolyether of Formula 2 can be contacted with 1 mole of 4 triphenyl-4-vinyl benzyl phosphonium chloride, about 2 mols to about 2.5 mols of styrene substituted perfluoropolyether of Formula 2 can be contacted with 1 mol of 4 triphenyl-4-vinyl benzyl phosphonium chloride, or about 2.2 mols to about 3 mols of styrene substituted perfluoropolyether of Formula 2 can be contacted with 1 mol of triphenyl-4-vinyl benzyl phosphonium chloride.
A wide range of weight ratios of styrene substituted perfluoropolyether of Formula 2 can be contacted with triphenyl-4-vinyl benzyl phosphonium chloride. For example, about 90) wt % styrene substituted perfluoropolyether of Formula 2 can be contacted with about 10 wt % triphenyl-4-vinyl benzyl phosphonium chloride, about 80 wt % styrene substituted perfluoropolyether of Formula 2 can be contacted with about 20 wt % triphenyl-4-vinyl benzyl phosphonium chloride, about 70) wt % styrene substituted perfluoropolyether of Formula 2 can be contacted with about 30 wt % triphenyl-4-vinyl benzyl phosphonium chloride, or about 60) wt % styrene substituted perfluoropolyether of Formula 2 can be contacted with about 40 wt % triphenyl-4-vinyl benzyl phosphonium chloride.
The styrene substituted perfluoropolyether of Formula 2 can be added to Mixture 3 in a weight percent of from about 10 wt % to about 90 wt %, based on the total weight of Mixture 3 or based on the total weight of styrene substituted perfluoropolyether of Formula 2 triphenyl-4-vinyl benzyl phosphonium, chloride radical initiator, and a solvent.
The triphenyl-4-vinyl benzyl phosphonium chloride can be added to Mixture 3 in a weight percent of from about 10 wt % to about 90 wt %, based on the total weight of Mixture 3 or based on the total weight of styrene substituted perfluoropolyether of Formula 2 triphenyl-4-vinyl benzyl phosphonium, chloride radical initiator, and a solvent.
A radical initiator can be added to Mixture 3 to commence a free radical polymerization reaction. The free radical initiator can be activated thermally, photochemically, or through an oxidation-reduction reaction. The free radical initiator can be added to Mixture 3 in an amount of about 0.02 wt % to about 10 wt %, based on the total weight of the radical initiator, styrene substituted perfluoropolyether of Formula 2, and triphenyl-4-vinyl benzyl phosphonium chloride.
The radical initiators can include, but are not limited to: azo compounds, peroxides, hydroperoxides, and persulfates. Exemplary azo compounds include 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 2,2′-azobis(2-amidinopropane)dihydrochloride, and 4,4′-azobis-(4-cyanopentanoic acid). Examples of commercially available thermal azo compound initiators include materials available from DuPont Specialty Chemical (Wilmington, Del.) under the “VAZO” trade designation such as VAZO 44, VAZO 56, and VAZO 68. Suitable peroxides and hydroperoxides can include acetyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, and peroxyacetic acid. Suitable persulfates can include sodium persulfate and ammonium persulfate. The free radical initiator can also include ammonium or sodium persulfate, N,N,N′,N′-tetramethylethylenediamine (TMEDA), ferrous ammonium sulfate: ferrous ammonium sulfate: cumene hydroperoxide and N,N-dimethylaniline.
The solvents for Mixture 3 can include, but is not limited to: acetic acid, acetone, acetonitrile, benzene, 1-butanol, 2-butanol, 2-butanone, t-butyl alcohol, carbon tetrachloride, chlorobenzene, chloroform, cyclohexane, 1,2-dichloroethane diethylene glycol diethyl ether, diglyme diethylene glycol dimethyl ether, N,N-dimethylformamide, 1,2-dimethoxy-ethane, dimethyl sulfoxide, 1,4-dioxane, ethanol, ethyl acetate, ethylene glycol, glycerin, heptane, hexamethylphosphoramide, hexamethylphosphorous triamide, hexane, isooctane, isododecane, methanol, methyl t-butyl ether, methylene chloride, N-methyl-2-pyrrolidinone, nitromethane, n-octane pentane, petroleum ether, 1-propanol, 2-propanol, pyridine, tetrahydrofuran, toluene, triethyl amine, triethyl amine, water, o-xylene, m-xylene, and p-xylene.
Reaction 3 or Mixture 3 can be heated to a temperature from a low of about 0° C., about 15° C., and about 25° C., to a high of about 35° C., about 65° C., and about 100° C. For example, Mixture 3 can be at room temperature. In another example, Mixture 1 can be heated to a temperature between about 25° C., to about 28° C., 25° C., to about 35° C., or 30° C., to about 45° C., 43° C., to about 78° C.
Reaction 3 or Mixture 3 can be reacted and/or stirred for a Reaction Time 3. Reaction Time 3 can be from a short of about 15 s, about 120 s, or about 300 s, to a long of about 24 h, about 96 h, or about 1 one week. For example, Reaction Time 3 can be from about 1 min to about 15 min, about 5 min to about 45 min, about 60 min to about 2 h, about 35 min to about 80 h, about 1 h to about 5 h, about 5 h to about 50 h, about 1 min to about 15 min, about 24 h to about 96 h, and about 40 h to about 1 week.
Reaction 3 or Mixture 3 can be reacted and/or stirred in an open reaction container or a closed container. Reaction 3 or Mixture 3 can be reacted and/or stirred under a vacuum. Reaction 3 or Mixture 3 can be reacted and/or stirred under an inert atmosphere, such as He, Ne, Ar, N2, and Ar.
The Reactions and/or Mixutes for making the styrenic fluoropolymers and/or anion exchange resins can have a viscosity that varies widely. For example, the Reactions and/or Mixutes can have a viscosity from a low of about 100 cP, about 1,000 cP, or about 100,000 cP, to a high of about 250,000 cP, about 900,000 cP, or about 2,500,000 cP. In another example, the Reactions and/or Mixutes can have a viscosity from about 100 cP to about 2,500,000 cP, about 1,000 cP to about 250,000 cP, about 2,500 cP to about 250,000 cP, about 2,500 cP to about 200,000 cP, about 10,000 cP to about 100,000 cP, about 10,000 cP to about 50,000 cP, about 100,000 cP to about 250,000 cP, about 620,000 cP to about 850,000 cP, about 700,000 cP to about 750,000 cP, about 700,000 cP to about 800,000 cP, about 650,000 cP to about 855,000 cP, about 700,000 cP to about 800,000 cP, about 500,000 cP to about 1,000,000 cP, or about 500,000 cP to about 2,500,000 cP. The viscosity of the Reactions and/or Mixutes can be measured on a Brookfield viscosimeter. The viscosity of the Reactions and/or Mixutes can be measured at various temperatures, such as 25° C., 40° C., 60° C., and 100° C.
Once the free radical polymerization reaction has been initiated, the forming polymeric material can precipitate. The particles of the styrenic fluoropolymer of Formula 1 can be isolated, for example, by filtration or decantation. Suitable solvents for filtration or decantation can include example, water, acetone, methanol, ethanol, n-propanol, and iso-propanol), dimethylsulfoxide, dimethylformamide, N-methylpyrrolidone, and acetonitrile. The resulting styrenic fluoropolymer of Formula 1 can be dried using any suitable method. In some embodiment, the resulting styrenic fluoropolymer of Formula 1 can be fractionated using techniques such as screening, sedimentation, and classification.
In an embodiment, the styrenic fluoropolymers of Formula 1 can be used as an anion exchange resin and/or anion exchange polymer. In another embodiment, the styrenic fluoropolymers of Formula 1 can be added to and/or incorporated in an anion exchange resin and/or anion exchange polymer. The styrenic fluoropolymer of Formula 1 and/or anion exchange resin can adsorb various negatively charged materials, such as negatively charged PFAS, through interaction with the positively charged groups on the anion exchange resin and typically adsorb relatively small amount of material on the non-ionic portions of the anion exchange resin. This low non-specific adsorption can advantageously result in better separation or purification of negatively charged target materials from other materials in a sample.
The styrenic fluoropolymers and/or anion exchange resin can include irregular shape particles or can be spherical or roughly spherical particles. The particles can have an average size from small of about 1 mm, to a large of about 100 mm. For example, the particles can have an average size of at least 20 mm, at least 30 mm, at least 40 mm, at least 50 mm, or at least 60 mm. The particles usually have an average size no greater than 2,000 mm, no greater than 1,000 mm, no greater than 500 mm, or no greater than 200 mm. In some applications, the anion exchange resins have an average particle size of 10 to 2,000 mm, 20 to 2,000 mm, 20 to 500 mm, 50 to 500 mm, 20 to 200 mm, 50 to 200 mm, 50 to 100 mm, 50 to 75 mm, 50 to 70 mm, or 60 to 70 mm.
The styrenic fluoropolymers and/or anion exchange resin can have a distribution of pore sizes. For example, the pore diameters of the anion exchange resin can be from a low of about 1 nm to a high of about 1,000.
The styrenic fluoropolymers and/or anion exchange resin can have surface area from a low about 10 m2/g to a high of about 20 m2/g. The surface area can be in the range of about 20 m2/g to about 200 m2/g, about 30 m2/g to about 200 m2/g, about 20 m2/g to about 100 m2/g, about 30 m2/g to about 100 m2/g, or about 40 m2/g to about 200 m2/g.
In an embodiment, a method for at least partially separating one or more perfluoroalkyl and polyfluoroalkyl substances from a mixture can include, but is not limited to: contacting a mixture containing one or more perfluoroalkyl or poly fluoroalkyl substances with a styrenic fluoropolymer of Formula 1 and separating the styrenic fluoropolymer of Formula 1 from the mixture after the content of the one or more perfluoroalkyl or polyfluoroalkyl substances has been reduced.
Many kinds of perfluoro alkyl and/or polyfluoro alkyl substances can be at least partially removed from mixtures by using a styrenic fluoropolymer of Formula 1 or an anion exchange resin containing a styrenic fluoropolymer of Formula 1. For example, the perfluoro alkyl and/or polyfluoro alkyl substances that can be at least partially removed from a mixture can include, but is not limited to: perfluorooctanoic acid, perfluorooctane sulfonic acid, perfluorooctylsulfonyl fluoride; perfluorododecanoic acid; pentadecafluorooctanoyl fluoride, perfluorooctanoic acid; 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoro-1-heptanesulfonyl fluoride; perfluorodecanoic acid; silver(I) perfluorooctanoate; sodium perfluorooctanoate; perfluorohexanesulfonic acid; perfluorobutane sulfonic acid; perfluorononanoic acid; perfluorotetradecanoic acid; 2-[ethyl[(heptadecafluorooctyl)sulfonyl]amino]ethyl methacrylate; methyl 2-perfluorooctanoate; [butyl[(heptadecafluorooctyl)sulfonyl]amino]ethyl acrylate; 2-[ethyl[(heptadecafluorooctyl)sulfonyl]amino]ethyl acrylate; perfluorooctyl iodide; 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluoro-1-decanol; 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosafluoro-1-dodecanol; 3-[[(heptadecafluorooctyl)sulfonyl]amino]-N,N,N-trimethyl-1-propanaminium iodide; N-ethyl-N-(2-hydroxyethyl)perfluorooctanesulfonamide; perfluorooctane sulfonic acid; 2-methyl-, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl ester 2-propenoic acid; 1,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8-heptadecafluoro-10-iodo-decane; 1,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-heneicosafluoro-12-iodo-dodecane; 2-methyl-, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosafluorododecyl ester; N-butyl-1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-N-(2-hydroxyethyl)-1-octanesulfonamide; 1,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-heneicosafluoro-12-iodo-dodecane; potassium perfluorooctanoate; potassium perfluorooctanesulfonate; N-ethyl-N-[(heptadecafluorooctyl)sulfonyl] glycine; ammonium perfluorooctanoate; potassium undecafluorocyclohexanesulphonate cyclohexanesulfonic acid; potassium 1,1,2,2,3,3,4,4,5,5,6,6,6-tridecafluoro-1-hexanesulfonic acid; sulfluramid; 2-propenoic acid, 2-methyl-, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,15,15,16,16,16-nonacosafluorohexadecyl ester; 2-Propenoic acid, 2-methyl-, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14-pentacosafluorotetradecyl ester; hexafluoropropylene oxide dimer acid; octadecanoic acid, pentatriacontafluoro-; 1-nonanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-nonadecafluoro-, ammonium salt; 1,1,2,2-tetrahydroperfluorododecyl acrylate; perfluorooctyl ethylene; 1-octanesulfonamide, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-N-(2-hydroxyethyl)-N-methyl-; 2-[[(heptadecafluorooctyl)sulfonyl]methylamino]ethyl acrylate; 1-decanesulfonyl chloride, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluoro-; 1-dodecanesulfonyl chloride, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosafluoro-; 1,1,2,2-tetrahydroperfluorodecyl acrylate; 1-octanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-, ammonium salt; poly (oxy-1,2-ethanediyl), α-[2-[ethyl[(heptadecafluorooctyl)sulfonyl]amino]ethyl]-ω-hydroxy-;
potassium perfluorobutane sulfonate; lithium (perfluorooctane)sulfonate; tetradecane, 1,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12-pentacosafluoro-14-iodo-; 1-Octanesulfonamide, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-N-methyl-; 1,1,2,2-tetrahydroperfluorohexadecyl acrylate; 1,1,2,2-tetrahydroperfluorotetradecyl acrylate; poly [oxy(methyl-1,2-ethanediyl)], α-[2-[ethyl[(heptadecafluorooctyl)sulfonyl]amino]ethyl]-ω-hydroxy-; 1-propanaminium, 3-[[(heptadecafluorooctyl)sulfonyl]amino]-N,N,N-trimethyl-, chloride; 1-tetradecanol, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14-pentacosafluoro-; perfluorobutanesulfonate; 1-propanaminium, N,N,N-trimethyl-3-[[(tridecafluorohexyl)sulfonyl]amino]-, chloride; glycine, N-[(heptadecafluorooctyl)sulfonyl]-N-propyl-, potassium salt; poly (oxy-1,2-ethanediyl), α-[2-[ethyl[(tridecafluorohexyl)sulfonyl]amino]ethyl]-ω-hydroxy-; ethanaminium, N,N,N-triethyl-, salt with 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-1-octanesulfonic acid (1;1); 2-propenoic acid, 2-[ethyl[(pentadecafluoroheptyl)sulfonyl]amino]ethyl ester; 1-heptanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoro-, potassium salt; 1-hexadecanol, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,15,15,16,16,16-nonacosafluoro-; pyridinium, 1-(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)-, salt with 4-methylbenzenesulfonic acid (1:1); hexafluoropropylene oxide dimer acid ammonium salt; hexadecane, 1,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14-nonacosafluoro-16-iodo-; poly(difluoromethylene), α-fluoro-ω-(2-hydroxyethyl)-, 2-hydroxy-1,2,3-propanetricarboxylate (3:1); poly(difluoromethylene), α-fluoro-ω-[2-(phosphonooxy)ethyl]-; poly(difluoromethylene), α,α′-[phosphinicobis(oxy-2,1-ethanediyl)]bis[ω-fluoro-; ethanol, 2,2′-iminobis-, compd. with α-fluoro-ω-[2-(phosphonooxy)ethyl]poly(difluoromethylene) (2:1); ethanol, 2,2′-iminobis-, compd. with α,α′-[phosphinicobis(oxy-2,1-ethanediyl)]bis[ω-fluoropoly(difluoromethylene)] (1:1); poly(difluoromethylene), α-fluoro-ω-[2-[(1-oxooctadecyl)oxy]ethyl]-; poly(difluoromethylene), α-fluoro-ω-[2-[(2-methyl-1-oxo-2-propenyl)oxy]ethyl]-; poly(difluoromethylene), α-[2-[(2-carboxyethyl)thio]ethyl]-ω-fluoro-, lithium salt; poly(difluoromethylene), α,α′-[phosphinicobis(oxy-2,1-ethanediyl)]bis[ω-fluoro-, ammonium salt; poly(difluoromethylene), α-fluoro-ω-[2-(phosphonooxy)ethyl]-, monoammonium salt; poly(difluoromethylene), α-fluoro-ω-[2-(phosphonooxy)ethyl]-, diammonium salt; ethanol, 2,2′-iminobis-, compd. with α-fluoro-ω-[2-(phosphonooxy)ethyl]poly(difluoromethylene) (1:1); poly(difluoromethylene), α-[2-[(2-carboxyethyl)thio]ethyl]-ω-fluoro-; poly(oxy-1,2-ethanediyl), α-hydro-ω-hydroxy-, ether with α-fluoro-ω-(2-hydroxyethyl)poly(difluoromethylene) (1:1); poly(difluoromethylene), α-fluoro-ω-(2-hydroxyethyl)-, dihydrogen 2-hydroxy-1,2,3-propanetricarboxylate; poly(difluoromethylene), α-fluoro-ω-(2-hydroxyethyl)-, hydrogen 2-hydroxy-1,2,3-propanetricarboxylate; 2-propenoic acid, esters, 2-methyl-, dodecyl ester, polymer with α-fluoro-ω-[2-[(2-methyl-1-oxo-2-propen-1-yl)oxy]ethyl]poly(difluoromethylene); 2-propenoic acid, 2-methyl-, dodecyl ester, polymer with α-fluoro-ω-[2-[(2-methyl-1-oxo-2-propen-1-yl)oxy]ethyl]poly(difluoromethylene) and N-(hydroxymethyl)-2-propenamide; poly(difluoromethylene), α-fluoro-ω-[2-[(1-oxo-2-propenyl)oxy]ethyl]-, homopolymer; ethanaminium, N,N-diethyl-N-methyl-2-[(2-methyl-1-oxo-2-propenyl)oxy]-, methyl sulfate, polymer with 2-ethylhexyl 2-methyl-2-propenoate, α-fluoro-ω-[2-[(2-methyl-1-oxo-2-propenyl)oxy]ethyl]poly(difluoromethylene), 2-hydroxyethyl 2-methyl-2-propenoate and N-(hydroxymethyl)-2-propenamide; cyclohexanesulfonic acid, decafluoro(pentafluoroethyl)-, potassium salt; glycine, N-ethyl-N-[(undecafluoropentyl)sulfonyl]-, potassium salt; glycine, N-ethyl-N-[(tridecafluorohexyl)sulfonyl]-, potassium salt; 2-propenoic acid, 2-[methyl[(undecafluoropentyl)sulfonyl]amino]ethyl ester; 2-propenoic acid, 2-[methyl[(tridecafluorohexyl)sulfonyl]amino]ethyl ester; 1-propanaminium, N,N,N-trimethyl-3-[[(pentadecafluoroheptyl)sulfonyl]amino]-, iodide; glycine, N-ethyl-N-[(pentadecafluoroheptyl)sulfonyl]-, potassium salt; perfluoropalmitic acid; 1-decanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heneicosafluoro-, ammonium salt; 1-octanesulfonamide, N-ethyl-1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-N-[2-(phosphonooxy)ethyl]-, diammonium salt; 2-propenoic acid, 2-[methyl[(pentadecafluoroheptyl)sulfonyl]amino]ethyl ester; thiols, C4-10, γ-ω-perfluoro; thiols, C6-12, γ-ω-perfluoro; thiols, C10-20, γ-ω-perfluoro; chromium(III) perfluorooctanoate; cyclohexanesulfonic acid, nonafluorobis(trifluoromethyl)-, potassium salt; cyclohexanesulfonic acid, decafluoro(trifluoromethyl)-, potassium salt; alkyl iodides, C4-20, γ-ω-perfluoro; 2-propenoic acid, 2-methyl-, 2-ethylhexyl ester, polymer with α-fluoro-ω-[2-[(2-methyl-1-oxo-2-propen-1-yl)oxy]ethyl]poly(difluoromethylene), 2-hydroxyethyl 2-methyl-2-propenoate and N-(hydroxymethyl)-2-propenamide; 1-heptanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoro-, ammonium salt; 1-hexanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,6-tridecafluoro-, ammonium salt; 1-pentanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,5-undecafluoro-, ammonium salt; poly[oxy(methyl-1,2-ethanediyl)], α-[2-[ethyl[(tridecafluorohexyl)sulfonyl]amino]ethyl]-ω-hydroxy-; poly[oxy(methyl-1,2-ethanediyl)], α-[2-[ethyl[(pentadecafluoroheptyl)sulfonyl]amino]ethyl]-ω-hydroxy-; 2-propenoic acid, 2-[butyl[(heptadecafluorooctyl)sulfonyl]amino]ethyl ester, telomer with 2-[butyl[(pentadecafluoroheptyl)sulfonyl]amino]ethyl 2-propenoate, methyloxirane polymer with oxirane di-2-propenoate, methyloxirane polymer with oxirane mono-2-propenoate and 1-octanethiol; poly(oxy-1,2-ethanediyl), α-[2-[ethyl[(undecafluoropentyl)sulfonyl]amino]ethyl]-o-hydroxy-; poly(oxy-1,2-ethanediyl), α-[2-[ethyl[(pentadecafluoroheptyl)sulfonyl]amino]ethyl]-ω-hydroxy-; poly[oxy(methyl-1,2-ethanediyl)], α-[2-[ethyl[(undecafluoropentyl)sulfonyl]amino]ethyl]-ω-hydroxy-; alcohols, C8-14, γ-ω-perfluoro; 1,4-benzenedicarboxylic acid, dimethyl ester, reaction products with bis(2-hydroxyethyl)terephthalate, ethylene glycol, α-fluoro-ω-(2-hydroxyethyl)poly(difluoromethylene), hexakis(methoxymethyl)melamine and polyethylene glycol; 1-pentanesulfonamide, 1,1,2,2,3,3,4,4,5,5,5-undecafluoro-N-(2-hydroxyethyl)-N-methyl-; 1-hexanesulfonamide, 1,1,2,2,3,3,4,4,5,5,6,6,6-tridecafluoro-N-(2-hydroxyethyl)-N-methyl-; 1-heptanesulfonamide, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoro-N-(2-hydroxyethyl)-N-methyl-; 1-propanaminium, N,N,N-trimethyl-3-[[(pentadecafluoroheptyl)sulfonyl]amino]-, chloride; 1-tetradecanesulfonyl chloride, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14-pentacosafluoro-; 2-propenoic acid, 2-[[(heptadecafluorooctyl)sulfonyl]methylamino]ethyl ester, polymer with 2 [methyl[(nonafluorobutyl)sulfonyl]amino]ethyl 2-propenoate, 2-[methyl[(pentadecafluoroheptyl)sulfonyl]amino]ethyl 2-propenoate, 2-[methyl[(tridecafluorohexyl)sulfonyl]amino]ethyl 2-propenoate, 2-[methyl[(undecafluoropentyl)sulfonyl]amino]ethyl 2-propenoate and α-(1-oxo-2-propenyl)-ω-methoxypoly(oxy-1,2-ethanediyl); 1-propanaminium, N,N,N-trimethyl-3-[[(undecafluoropentyl)sulfonyl]amino]-, chloride; 1-propanaminium, N,N,N-trimethyl-3-[[(undecafluoropentyl)sulfonyl]amino]-, iodide; 1-propanaminium, N,N,N-trimethyl-3-[[(tridecafluorohexyl)sulfonyl]amino]-, iodide; 1-heptanesulfonamide, N-ethyl-1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoro-; poly(oxy-1,2-ethanediyl), α-[2-[ethyl[(pentadecafluoroheptyl)sulfonyl]amino]ethyl]-ω-methoxy-; poly(oxy-1,2-ethanediyl), α-[2-[ethyl[(heptadecafluorooctyl)sulfonyl]amino]ethyl]-ω-methoxy-; 1-octanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-, compd. with 2,2′-iminobis[ethanol] (1:1); 1-heptanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoro-, compd. with 2,2′-iminobis[ethanol] (1:1); 1-hexanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,6-tridecafluoro-, compd. with 2,2′-iminobis[ethanol] (1:1); 1-pentanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,5-undecafluoro-, compd. with 2,2′-iminobis[ethanol] (1:1); thiols, C8-20, γ-ω-perfluoro, telomers with acrylamide; poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy-, 2-hydroxy-3-[(γ-ω-perfluoro-C6-20-alkyl)thio]propyl ethers; fatty acids, C6-18, perfluoro, ammonium salts; fatty acids, C7-13, perfluoro, ammonium salts; silane, trichloro(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)-; poly(difluoromethylene), α-fluoro-ω-[2-sulphoethyl)-; silane, (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)trimethoxy-; poly(difluoromethylene), α-fluoro-ω)-[2-(phosphonooxy)ethyl]-, ammonium salt; thiocyanic acid, γ-ω-perfluoro-C4-20-alkyl esters; alkenes, C8-14 α-, δ-ω-perfluoro; disulfides, bis(γ-ω-perfluoro-C6-20-alkyl); silicic acid (H4SiO4), disodium salt, reaction products with chlorotrimethylsilane and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluoro-1-decanol; siloxanes and silicones, (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)oxy Me, hydroxy Me, Me octyl, ethers with polyethylene glycol mono-Me ether; 1,3-propanediol, 2,2-bis[[(γ-ω-perfluoro-C4-10-alkyl)thio]methyl] derivs., phosphates, ammonium salts; 1,3-propanediol, 2,2-bis[[(γ-ω-perfluoro-C6-12 alkyl)thio]methyl] derivs., phosphates, ammonium salts; 1,3-propanediol, 2,2-bis[[(γ-ω perfluoro-C10-20-alkyl)thio]methyl] derivs., phosphates, ammonium salts; 2-propenoic acid, 2-methyl-, 2-(dimethylamino)ethyl ester, polymers with Bu acrylate, γ-ω-perfluoro-C8-14-alkyl acrylate and polyethylene glycol monomethacrylate, 2,2′-azobis[2,4 dimethylpentanenitrile]-initiated; 1-octanesulfonamide, N-[3-(dimethyloxidoamino)propyl]-1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-, potassium salt; fatty acids, linseed-oil, γ-ω-perfluoro-C8-14-alkyl esters; sulfonic acids, C6-12-alkane, γ-ω-perfluoro, ammonium salts; ethaneperoxoic acid, reaction products with 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl thiocyanate and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl thiocyanate; 2-propenoic acid, 2-methyl-, 2-(dimethylamino)ethyl ester, polymers with γ-ω-perfluoro-C10-16-alkyl acrylate and vinyl acetate, acetates; 2-propenoic acid, 2-methyl-, polymer with butyl 2-methyl-2-propenoate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl 2-propenoate, 2-hydroxyethyl 2-methyl-2-propenoate and methyl 2-methyl-2-propenoate; 2-propenoic acid, 2-methyl-, hexadecyl ester, polymers with 2-hydroxyethyl methacrylate, γ-ω-perfluoro-C10-16-alkyl acrylate and stearyl methacrylate; propanedioic acid, mono(γ-ω-perfluoro-C8-12-alkyl) derivs., di-me esters; propanedioic acid, mono(γ-ω-perfluoro-C8-12-alkyl) derivs., bis[4-(ethenyloxy)butyl] esters; 1,3-propanediol, 2,2-bis[[(γ-ω-perfluoro-C6-12-alkyl)thio]methyl] derivs., polymers with 2,2-bis[[(γ-ω-perfluoro-C10-20-alkyl)thio]methyl]-1,3-propanediol, 1,6-diisocyanato-2,2,4(or 2,4,4)-trimethylhexane, 2-heptyl-3,4-bis(9-isocyanatononyl)-1-pentylcyclohexane and 2,2′-(methylimino)bis[ethanol]; thiols, C4-20, γ-ω-perfluoro, telomers with acrylamide and acrylic acid, sodium salts
Many kinds of mixtures that include one or more perfluoro alkyl and/or polyfluoro alkyl substances can be contacted with a styrenic fluoropolymer of Formula 1 to at least partially reduce the one or more perfluoro alkyl and/or polyfluoro alkyl substances. For example, an aqueous mixture of one or more perfluoro alkyl and/or polyfluoro alkyl substances can be contacted with a styrenic fluoropolymer of Formula 1 to at least partially reduce the one or more perfluoro alkyl and/or polyfluoro alkyl substances, resulting in a water mixture that has less perfluoro alkyl and/or polyfluoro alkyl substances.
In an embodiment, a styrenic fluoropolymer of Formula 1 and/or anion exchange resin can be added to an anion exchange vessel. A flow of an aqueous mixture containing one or more PFAS can be introduced to the anion exchange vessel such that the PFAS bind to the styrenic fluoropolymer of Formula 1 and/or anion exchange resin and are thereby removed from the water. A regenerant solution can be introduced to the anion exchange vessel to desorb the PFAS from the styrenic fluoropolymer of Formula 1 and/or anion exchange resin thereby regenerating the anion exchange resin and generating a spent regenerant solution that can include the desorbed PFAS and the regenerant solution. The spent regenerant solution can subjected to a separation and recovery process to recover the regenerant solution for reuse and separate and concentrate the removed PFAS.
A sample containing negatively charged materials, such as PFAS, can be contacted with the styrenic fluoropolymers and/or anion exchange resins at a pH where the anion exchange resin has positively charged groups (e.g., at a pH of 1 to 10). In general, to get effective adsorption of the negatively charged material to the anion exchange resin, a pH of at least about 1 to 2 pH units above the pK of the material can be used. To release the adsorbed material from the styrenic fluoropolymers and/or anion exchange resins, if desired, the pH can be lowered at least 1 to 2 pH units, or more. The adsorption and release processes are typically performed at temperatures near room temperature.
In an embodiment, buffer salts can be used for controlling pH include, but are not limited to, sodium phosphate, sodium carbonate, sodium bicarbonate, sodium borate, sodium acetate, tris(hydroxymethyl)aminomethane, 3-morpholinopropanesulfonic acid, 4-(2-hydroxyethyl)piperazine-1-propanesulfonic acid, and 2-morpholinoethanesulfonic acid.
In an embodiment, the styrenic fluoropolymers and/or anion exchange resins can be used in a chromatographic column. When packed with the styrenic fluoropolymers and/or anion exchange resins, the chromatographic column can be used to separate an ionic material from non-ionic materials or to separate one ionic material from another ionic material with a different charge density. Suitable columns are known in the art and can be constructed of such materials as glass, polymeric material, stainless steel, titanium and alloys thereof, or nickel and alloys thereof. Methods of filling the column to effectively pack the anion exchange resin in the column are known in the art.
The chromatographic columns can be part of an analytical instrument such as a liquid chromatograph. The chromatographic columns can be part of a preparative liquid chromatographic system to separate or purify an ionic material. The preparative liquid chromatographic system can be a laboratory scale system, a pilot plant scale system, or an industrial scale system.
To provide a better understanding of the foregoing discussion, the following non-limiting examples are offered. Although the examples can be directed to specific embodiments, they are not to be viewed as limiting the invention in any specific respect.
All chemicals and materials used in experiments were obtained from commercial suppliers and used as received without any further purification unless otherwise stated. Di alcohol terminated perfluoropolyether (PFPE) compound, Fluorolink E10 H (Average MW˜1700 amu) was obtained from Solvay Solexis, Inc. 4-vinyl benzyl chloride (90%) was obtained from Acros Organics and sodium hydride (60% dispersion in paraffin liquid) was obtained from TCI chemicals. Triphenyl phosphine (>99%), azobisisobutyronitrile (AIBN) was purchased from Sigma-Aldrich and ethylene glycol, DMF (HPLC grade) was purchased from Oakwood Chemicals. Perfluorooctanoic acid (PFOA, 96%) and potassium perfluorooctane sulfonate potassium salt (PFOS, 98%) were obtained from Sigma Aldrich and Matrix Scientific respectively. Activated carbon powder (Charcoal) U.S.P. was supplied from Mallinckrodt chemicals. Methanol (99.9%), anhydrous diethyl ether (99%), ethyl acetate (>99.5%), hexane (99.5%), dichloromethane (>99.5%) was obtained from Fisher Scientific and used as received. CDCl3 (0.03% v/v TMS; Thermo Scientific; 99.8%) and DMSO-d6 (Thermo Scientific; 99.5%) were used as NMR solvents. Deionized water (Resistivity˜18 MΩ) obtained by passing through ion exchange columns is utilized to prepare solutions; local tap drinking water (Louisiana, Lafayette) and commercial RO purified bottled drinking water (Great Value, USA) was used as the drinking water matrices in some experiments. Lake water was collected from Lake Martin, Louisiana and filtered through 0.45 mm syringe filter before use in experiments. All other chemicals and materials employed were of analytical grade and used as received unless otherwise mentioned.
Commercially available Fluorolink E10-H was chosen as the precursor which is perfluoropolyether (PFPE) with a linear structure terminated with an —OH groups at both ends of an ethoxyilic chain for the development of ion-exchange polymer resin with tunable functionality.54,55 Amorphous, low-molecular-weight perfluorinated oligomers, or PFPEs, are produced from the gas phase without the use of perfluorinated surfactants.56 Styrene groups at the chain ends were installed in the PFPE by effectively substituting the primary alcohol groups following a general protocol adopted from Kurth and co-workers57 with some modifications detailed in the experimental procedure. The first step involved reacting the terminal alcohol groups of the PFPE with the strong base, sodium hydride NaH via hydrogen abstraction evolving H2, to selectively convert —OH into the corresponding alkoxide derivative of PFPE. In-situ generated alkoxide form of PFPE undergoes nucleophilic aromatic substitution reaction in presence of 4-vinyl benzyl chloride at low temperature to form styrene terminated perfluoropolyether monomer compound as the major reaction product (Step-I). The 1H NMR spectrum of styrene substituted monomer product revealed the successful installation of styrene groups at the monomer chain end, based on the appearance of well-resolved resonances in the d 5.3-7.6 region for styrene unit as well as the appearance of PFPE proton resonances in the region from d 3.39-3.55 ppm (
Triphenyl-4-vinylbenzyl phosphonium chloride monomer was synthesized by nucleophilic substitution reaction between triphenyl phosphine and 4-vinyl benzyl chloride in a mole ratio of 1:2 at 40° C. in methanol as per the reaction scheme (Step II) following a method adapted from Biswas et.al.58 The 1H NMR spectrum of the compound displayed the characteristic resonances at d 7.03 and 7.14 for benzene ring protons of vinyl benzyl chloride and d 5.43 ppm for benzylic —CH2 protons connected to the phosphonium cation. Well-resolved proton resonances observed at d 6.59, 5.68, 5.23 were ascribed to three vinyl protons of the triphenyl-4-vinylbenzyl phosphonium chloride monomer as indicated in
Additionally, perfluoropolyether (PFPE) elastomer with no ionic component (without tetra aryl phosphonium units) served as controls for perfluorinated non-ionic compound with the fluorous component.
The FTIR spectra of the ionic fluoropolymer synthesized indicated successful polymerization of monomers with the disappearance of vinylic C═C stretching signal around 1632 cm−1 present in monomers (
Mainly PFOA (pKa˜0) and PFOS (pKa˜−3)59,60 were targeted as model PFAS contaminants in water remediation experiments using the ionic fluoropolymer. Initial PFAS removal efficiency studies by the fluoropolymer at polymer loading of 100 mg/L was evaluated by carrying out batch equilibrium adsorption experiments for PFOA/PFOS (Initial concentration of 35 ppb for each compound and additionally PFOS=0.5 ppb, 2.5 ppb, 38 ppb and PFOA=12 ppb) spiked in pure deionized water or tap drinking matrix for various time periods as depicted in the
The PFAS removal efficiency upon sorption by the ionic fluoropolymers and/or styrenic fluoropolymers can vary widely. For example, the PFAS removal efficiency upon sorption by the ionic fluoropolymer and/or styrenic fluoropolymers can be from about 1% to about 50%, about 1% to about 20%, about 5% to about 15%, about 10% to about 20%, or about 25% to about 75%.
To understand the degree of how electrostatic, and noncovalent interactions help cooperatively bind PFAS (PFOA/PFOS), adsorption kinetics of PFOA by various polymer adsorbents at relatively much higher concentrations (Initial PFOA concentration of 1.75 mM or ˜725 ppm, pH ˜2.48) and adsorbent loading of 1.5 mg/mL was studied by monitoring PFOA concentration at different time intervals using HPLC method.
Styrene-based ionic fluoropolymer designed here showed significantly higher sorption capacity (qt) of 343 mg/g for PFOA uptake in reference to commercial activated carbon standard displaying sorption capacity of 268 mg/g under otherwise identical experimental conditions studied (Table 1). In addition, the adsorption capacity of styrene-based ionic fluoropolymer was found to be far more superior, ˜4.9-fold higher than styrene-based ionic hydrocarbon polymer and ˜2.9-fold higher in comparison to non-ionic perfluoropolyether elastomer (Table 1). These results guided us to important design principles in the development of ionic fluropolymers that should include combination of both electrostatic component and fluorophilic units for rapid and efficient remediation of PFAS from waters.
With respect to the removal mechanism, it is hypothesized that the tethered quaternary phosphonium moieties in the styrene substituted ionic fluoropolymer exchanges with PFOA/PFOS anion in solution. Fluorinated nature of the perfluoropolyether backbone is favorable for PFAS (PFOA/PFOS) anion adsorption and ion-pairing with the tethered ionic head groups containing phosphonium cation units. Therefore, combination of both ionic (electrostatic) and noncovalent interactions (Vander Waals interaction) work cooperatively for promoting PFAS (PFOA/PFOS) uptake in the fluoropolymer aqueous solutions. To further understand structure-property correlation and study the selectivity of ionic fluoropolymer for PFOA/PFOS, we chose phenol as model oil-field hydrocarbon contaminant in presence of various ionic polymer adsorbents. We observed no meaningful adsorption of phenol by the styrene-based ionic fluoropolymer with removal efficiency approaching ˜2% monitored over a period of 60 minutes whereas styrene-based ionic hydrocarbon polymer showed slow kinetics of increasing phenol adsorption with maximum phenol removal efficiency of ˜12% over the same duration of 60 minutes (
After benchmarking the ionic polymer materials in the removal of representative perfluoroalkyl carboxylic acids (PFCAs) such as PFOA and PFOS anions in simulated water (
Furthermore, we tested the reusability of ionic fluoropolymer to be able to regenerate the fluoropolymer after PFOA sorption by soaking and mild agitation with 400 mM methanolic ammonium acetate solution to desorb PFOA and regenerate polymer for subsequent reuse cycles.
Styrene-based perfluorinated anion exchange polymer composition bearing quaternary tetra-aryl phosphonium cation moiety was synthesized by radical polymerization method. Ionic fluoropolymer exhibited excellent PFOA/PFOS removal at both ultralow environmentally relevant concentrations (sub-ppb level) and in concentrated stream of PFOA solutions with sorption capacity exceeding much greater than that of powdered activated carbon (charcoal) in batch equilibrium adsorption studies. Structure-property correlation studies performed by various ionic polymers showed critical requirement of fluorophilic groups along with cation units in highly selective PFOA/PFAS removal from waters in presence of organic hydrocarbons such as phenol. Irreversible electrostatic interaction through anion exchange coupled with noncovalent fluorophilic interactions drive PFAS removal by ionic fluoropolymer. Like in pure deionized water, ionic fluropolymer efficiently removed PFOA from real environmental water matrices collected from Lake Martin, Louisiana spiked with PFOA in presence of background inorganic constitutents, micropollutants and dissolved organic matter. Thus, this study has potential of the ionic fluoropolymers in developing water purification technologies targeting rapid and selective separation of perfluoroalkyl species from diverse PFAS compounds under environmentally relevant concentrations and beyond at target contaminated sites.
HPLC analyses of PFOA, and phenol were performed by employing high performance liquid chromatography (HPLC) with isocratic elution on an Agilent 1100 series instrument coupled with variable wavelength UV detector. PFOA was detected by Zorbax SB-C18 Rapid Resolution column (1.8 μm, 50×2.1 mm) while using methanol and 20 mM ammonium acetate mixture (75:25 v/v) as the mobile phase at a flow rate of 0.22 mL/min and detection wavelength of 210 nm for PFOA quantification.
Quantification of target perfluoroalkyl acids (PFCAs) post-equilibrium adsorption experiments by mass spectrometric measurements were conducted on a Bruker amaZon Speed ETD (Billerica, MA) ion trap mass spectrometer coupled to a Thermo Scientific Ultimate 3000 RS HPLC system (Waltham, MA). The system was controlled with Bruker TrapControl software (ver. 8.0) and Bruker Compass HyStar (Ver. 5.18.1). Samples were injected in flow through mode with an isocratic mobile phase composition consisting of 50% water with 0.1% formic acid and 50% acetonitrile with 0.1% formic acid, and the flow rate was kept at 0.4 mL/min. Capillary voltage was set at 4,500 V, while the end plate offset was 500 V. The nebulizer was set to deliver nitrogen gas at 35 psi, while the same gas was used for drying at a flow of 10 L/min and a temperature of 250° C. Spectra were acquired in negative mode with a single reaction monitoring approach. The ion trap was set to accumulate a mass window centered at 413 m/z for PFOA and 499 m/z for PFOS with a 2 Da width. The mass range monitored was 50-600 Da, and accumulation was carried with an ion charge control (ICC) of 200,000 or 10 ms, whichever condition was met first for each spectrum. The system smart parameter setting (SPS) was set to 413 and 3 scans were averaged to generate each data point. Fragmentation vas carried out with a relative amplitude of 100%, and the SmartFrag parameters were set to change this amplitude from 80 to 120% over a 40 ms time. Chromatograms were acquired with rolling averaging of 3 data points. Each sample was injected in three technical replicates.
Data analysis was carried out with Bruker Data Analysis (ver. 5.3). To generate the final chromatographic trace, the MS/MS signal was extracted to output the intensity of the 369 m/z fragment of PFOA which represents the loss of the carboxylic moiety whereas the PFOS was analyzed for signal isolated at m/z 499. Each generate extracted ion chromatogram was manually integrated, and the resulting data were used to calculate a calibration with values between 0.1 and 100 ppb.
MALDI analyses of perfluoropolyether compound (Fluorolink E10-H), and styrene functionalized perfluorinated monomer: MALDI-MS spectra of Fluorolink E10-H precursor and after styrene functionalization in the course of reaction were acquired using a MALDI-TOF/TOF mass spectrometer (UltrafleXtreme, Bruker Daltonics, Billerica, MA, USA) with 5 ppm mass accuracy. The sample is generally mixed with a matrix mixture (DHB, 2,5-dihydroxybenzoic acid in THF) and NaTFA, trifluoroacetic acid sodium salt (dopant) in equal amounts. A 1 μL aliquot of each mixture was deposited on the MALDI target plate. This approach is called “Dry droplet” method. The same mixture (1:1:1, sample, matrix, and dopant) was also recreated directly on plate by spiking a 1 μL of each component on the same sample well. This approach is called “on-plate mixing” method.
External calibration was performed with a standard mixture of peptides to verify intensity and resolution benchmarks. Spectra were recorded in negative ion mode in the mass range 700-3860 m/z. Each spot was irradiated in 40 random locations with 25 laser shots each, resulting in a total of 1000 laser shots. The signal from these 1000 shots was summed to generate a representative spectrum of each spot. If not otherwise stated, the same number of shots (1,000) was used to generate all spectra. The standard deviation of the calibration was 5 ppm. Data were analyzed with Bruker flexAnalysis 3.3 software and exported to mzXML file format for sharing purposes.
Solution state 1H and 13C NMR spectra were mainly recorded using a Bruker Avance AVIII-400 MHz NMR spectrometer or a Varian 400 MHz NMR spectrometer in specified deuterated solvents. Some 13C NMR spectra were recorded on High-Performance 60 MHz Benchtop NMR from Nanalysis.
Fourier transform infrared spectroscopy (FTIR) was performed using an Agilent Cary 630 attenuated total reflection (ATR) FTIR spectrometer in frequency range 650-4000 cm−1.
The Brunauer-Emmett-Teller (BET) surface area and the porosity of the fluoropolymer was measured by nitrogen physisorption data at 77 K obtained with the Nova Touch LX gas sorption analyzer from Quantachrome Instruments.
In a 100 ml round bottom flask, 8.50 gm (˜5 mmol) of perfluoropolyether diol compound (Fluorolink E10 H, Average MW ˜1700 amu) is dissolved in 15 mL DMF and flushed with N2. Sodium hydride, NaH in excess (0.46 gm, 3.9 eq., 19.46 mmol, hexane washed to remove oil) is slowly added to the Fluorolink E10 H while keeping flask in an ice bath and then allowed to stir for about 1.5 h at the room temperature. This is followed by dropwise addition of vinyl benzyl chloride (1.78 gm, 11.66 mmol, 2.3 eq.) into the above reaction mixture immersed in an ice bath (set at ˜10° C.) using a syringe pump and the reaction is allowed to continue up to 72 h while keeping the reaction temperature below 20° C. to obtain styrene substituted compound. Post reaction, DMF is removed under reduced pressure at ˜50° C. using the rotary evaporator. 125 mL of water is added to the reaction mixture and the solution is extracted thrice with 75 mL of dry diethyl ether or ethyl acetate using a separatory funnel.
Ether extracts are combined and then dried under vacuum to obtain the styrene substituted perfluoropolyether compound as light-yellow viscous liquid (yield, ˜5.80 gm).
1H NMR (400 MHz, DMSO-d6) δ 2.88 (residual DMF) 3.554-3.390 (broad), 4.637 (s), 5.379, 5.357 (d, J=8.8 Hz), 5.967, 5.932 (d, J=14 Hz), 6.825, 6.803, 6.790, 6.768 (dd), 7.615, 7.598 (d, J=6.8 Hz) 7.587, 7.570 (d, J=6.8 Hz)
Synthesis of 1,2-Bis (4-vinylbenzyloxy) ethane monomer is achieved following the protocol established from literature.1 Ethylene glycol (1.23 gm, 20 mmol) dissolved in DMF (40 mL) is treated with NaH (1.85 gm, 46 mmol) for 1 hour at room temperature followed by dropwise addition of 4-vinyl benzyl chloride (7.03 gm, 46 mmol) to the reaction flask submerged in an ice-cold water bath set at ˜10° C. and allowed to stir up to 22 h. Post-reaction DMF is removed under vacuum at 50° C. and 100 mL of water is added to reaction flask and the reaction product is purified by extraction thrice with 75 mL of dry diethyl ether in a separatory funnel. All ether extracts are combined and then dried under reduced pressure using rotary evaporator to obtain the light-yellow liquid product.
1H NMR (400 MHz, CDCl3) d 3.64 (s) 4.55 (s), 5.24, 5.21 (d, J=12 Hz), 5.75, 5.71 (d, J=16 Hz), 6.74, 6.71, 6.69, 6.66 (dd), 7.39, 7.37 (d, J=8 Hz) 7.31, 7.29 (d, J=8 Hz).
The synthesis of triphenyl 4-vinyl benzyl phosphoniun chloride is accomplished by following nucleophilic substitution reaction between triphenyl phosphine and 4-vinyl benzyl chloride at mild temperatures published elsewhere.2 In a typical procedure, triphenyl phosphene (5.58 gm, 21.29 mmol) and 4-vinyl benzyl chloride (6.50 gm, 42.58 mmol) in 1:2 molar ratio and 6 mL of dry methanol is placed in a 100 mL round bottom flask. The reaction flask is attached with reflux condenser and heated on pre-heated oil bath at 40° C. for 24 h under inert N2 atmosphere. After the reaction, methanol was evaporated using a rotary evaporator and the entire liquid mass was dissolved in 15 ml dichloromethane. The solid ionic monomer is isolated by precipitation in excess hexane (125 mL). The same purification process was repeated twice to obtain the solid monomer product (product yield˜7.35 gm), triphenyl 4-vinyl benzyl phosphonium chloride with ˜88% yield and kept in a refrigerator for subsequent use in copolymerization reaction.
1H NMR (400 MHz, CDCl3) d 5.296 (residual DCM) 5.230, 5.208 (d J=8.8 Hz), 5.677, 5.642 (d, J=14 Hz), 6.612, 6.590, 6.577, 6.555 (dd), 5.451, 5.422 (d) 7.141 (m), 7.051(m), 7.743-7.598 (m).
In a 20 mL scintillation vial equipped with magnetic stir bar, 1.60 gm of styrene substituted perfluoropolyether compound (1.60 gm, 80 wt %), triphenyl 4-vinyl benzyl phosphonium chloride (0.40 gm, 20 wt %), azobisisobutyronitrile (AIBN, 20 mg, 1 wt %) and DMF (2.0 gm) is placed. The vial is sealed with rubber septum and flushed with N2 for 5 minutes and then immersed in oil bath heated to 70° C. under stirring for 5 h in presence of inert N2 atmosphere. Solid gel like particles is obtained within 15-20 minutes and the entire mass is gelled after 1 h of reaction. After 5 h reaction, vial is naturally cooled to room temperature and solidified gel is finely grounded into powder form to obtain the cross-linked ionic fluoropolymer (yield˜1.90 gm) that is dried under vacuum at room temperature for application in water treatment experiments.
Similarly, in the preparation of non-fluorinated hydrocarbon-based ionic polymer analogue, proportional amounts of 1,2-Bis (4-vinylbenzyloxy) ethane monomer (0.40 gm, 80 wt %), triphenyl 4-vinyl benzyl phosphonium chloride monomer (0.1 gm, 20 wt %), azobisisobutyronitrile (AIBN, 5 mg, 1 wt %) all dissolved in DMF (0.5 gm) is taken in a 20 mL scintillation vial and copolymerization reaction is carried out for 5 h at 70° C. under N2 atmosphere to obtain the styrene-based hydrocarbon polymer solid which is finely grounded into powder using mortar and pestle.
Copolymerization reaction between 1,2-Bis(4-vinylbenzyloxy) ethane and triphenyl vinyl benzyl phosphonium chloride
For the development of new ion-exchange polymers in remediation of Per- and polyfluoro alkyl substances, styrenic fluoropolymers compositions containing a quaternary tetra-aryl phosphoniun bearing styrene moiety for styrenic fluoropolymers were made, and their selective removal of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)—a type of PFAS at sub-ppb level concentrations were demonstrated. Specially, the polymer selectively and rapidly removes PFAS with more than 90% removal efficiency from both deionized and drinking water in presence of other organic co-contaminants such as phenols coupled with excellent stability of polymer. By examining the polymer with different concentrations of PFAS tested, it is implied that ionic fluoropolymer designed herein favors PFOA and PFOS anions over other competing anions or organic species in solution via irreversible anion exchange facilitated by strong van der Waal forces of interactions with fluorine rich backbone of the polymer. Synthesis of the targeted fluoropolymer design, structural characterization, and polymer application in selective removal of PFAS is discussed.
This study has implications in developing water purification technologies targeting rapid and selective separation of perfluoroalkyl species under environmentally relevant concentrations.
(13C: 100 MHz, CDCl3), δ (ppm) 137.51, 135.93, 135.03, 134.34, 131.68, 130.22, 128.82, 126.50, 118.08, 114.78, 30.60
(1H: 400 MHz, CDCl3), δ (ppm) 7.70 (m, 15H), 7.13 (d, 8 Hz, 2H), 7.04 (d, 8 Hz, 2H), 6.59, (dd, 10.8 Hz, 17.6 Hz, 1H)
(1H: 400 MHz, CDCl3), δ (ppm) 7.43-7.26 (m, 8H), 6.73-6.68 (m, 1H), 7.75 (dd, 11.6 Hz, 14 Hz, 1H), 5.25 (dd, 8.4 Hz, 17.2 Hz, 1H), —OCH2 should be singlet, 3.88-3.62 (m, polymeric chain hydrogen),
13C: 15 MHz, DMSO-D6), δ (ppm) 136.48, 133.82, 129.44, 126.74, 115.11 (substituted styrene carbons), 71.50, 69.27, 67.18, 46.32 (perfluoro polyether carbons) 41.33-37.15 (DMSO-D6- septet)
(19F: 376 MHz, CDCl3), δ (ppm) 51.86-55.33 (—OCF2), 77.93 and 80.05 (—CF2), 88.97-88.99 and 90.81 (—OCF2CF2)
One of ordinary skill in the art will readily appreciate that alternative, but functionally equivalent components, materials, designs, and equipment may be used. The inclusion of additional elements may be deemed readily apparent and obvious to one of ordinary skill in the art. Specific elements disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to employ the present invention.
The term “alkyl” refers to a monovalent group that is a radical of an alkane, which is a saturated hydrocarbon. The alkyl can be linear, branched, cyclic, or combinations thereof and typically has 1 to 20 carbon atoms. In some embodiments, the alkyl group contains 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, and ethylhexyl.
The term “charged” refers to a material that has an ionic group as part of its chemical structure. A negatively charged material is an anion and a positively charged material is a cation. An oppositely charged counterion is typically associated with the ionic group. Adjusting the pH can alter the charge of some ionic groups.
Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application.
Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges including the combination of any two values, e.g., the combination of any lower value with any upper value, the combination of any two lower values, and/or the combination of any two upper values are contemplated unless otherwise indicated. It should also be appreciated that the numerical limits may be the values from the examples. Certain lower limits, upper limits and ranges appear in at least one claims below. All numerical values are “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.
This patent application claims the benefit of and priority to U.S. Provisional Application No. 63/330,864 entitled, “Styrenic Fluoropolymers and Methods For Making and Using Same” filed on Apr. 14, 2022, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63330865 | Apr 2022 | US |
