Per- or polyfluoroalkyl substances (PFAS) represent a large family of chemicals, widely used due to their outstanding properties. However, also known as "Forever Chemicals", they are raising attention due to high health and environmental risks. In last years, the elimination, degradation, or recycling of PFAS has become essential. In this work, the degradation of a perfluorosulfonic acid polymer, Nafion, composed of a poly(tetrafluoroethylene) backbone with perfluoroether side chains terminated by sulfonic acid groups, is studied. More precisely, the mechanochemical degradation, previously described for linear fluoropolymers, is reported on branched PFSA polymers in the presence of various activators (such as (pyro)phosphates, 1,8-Diazabicyclo [5.4.0]undec-7-ene (DBU), 1,5,7-Triazabicyclo [4.4.0]dec-5-ene(TBD), KOH) at room temperature. Recovered products were characterized over time by nuclear magnetic resonance and Fourier transformation infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, and liquid chromatography-mass spectrometry in order to both identify the released products and suggest a degradation pathway. The use of potassium hydroxide, although resulting in a moderate potassium fluoride yield, allowed the determination of fragments produced during the degradation mechanism, while others were ineffective. Phosphate salts have been revealed to be the best candidates enabling the mineralization of PFSA, yielding valuable products and a good fluorine recovery for a further circular economy.

ABSTRACT Rationale Direct analysis in real time (DART) is an open–air ion source that does not require a sample preparation step. Only a few studies have focused on the negative‐ion formation processes for low–polarity molecules. In this study, an ω‐iodo oligo (vinylidene fluoride) telomer of known composition was investigated to elucidate the involved DART ionization mechanisms. Methods A DART ionization source was coupled to a Fourier transform ion cyclotron resonance mass spectrometer (FT–ICR MS), whose high m/z measurement accuracy enabled the unambiguous assignment of molecular formulas to the detected ions. Tandem MS experiments were performed to confirm these assignments. Data interpretation and visualization were carried out using Kendrick plots. Results Numerous VDF telomer distributions were identified, each attributed to C 6 F 13 (C 2 H 2 F 2 ) n I or C 6 F 13 (C 2 H 2 F 2 ) n H, either in their deprotonated form or forming adducts or associations with I − , O 2 •− , NO 2 − , NO 3 − , HCO 2 − , HCO 3 − , CO 3 •− , and HCO 4 − . The [M + HCO 3 ] − and [M + HCO 4 ] − anions were the most abundant, highlighting the crucial role of carbonate–linked anions in the DART ionization of PVDF. This observation was further supported by neutral losses corresponding to H 2 CO 3 and H 2 CO 4 in tandem mass spectrometry experiments. Furthermore, the oxidative properties of HCO 4 − were emphasized. These results demonstrated the need to reinterpret data obtained in a previous DART‐MS study on PVDF samples with unknown end groups. Conclusions The complex and diverse ionization processes observed in the negative DART ionization of fluorinated telomers underline the need for careful data interpretation. The uncommon [M + HCO 3 ] − and [M + HCO 4 ] − adducts were found to play a significant role in the ionization of iodinated PVDF.

RATIONALE:Direct analysis in real time (DART) is an open-air ion source that does not require a sample preparation step. Only a few studies have focused on the negative-ion formation processes for low-polarity molecules. In this study, an ω-iodo oligo (vinylidene fluoride) telomer of known composition was investigated to elucidate the involved DART ionization mechanisms. METHODS:A DART ionization source was coupled to a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS), whose high m/z measurement accuracy enabled the unambiguous assignment of molecular formulas to the detected ions. Tandem MS experiments were performed to confirm these assignments. Data interpretation and visualization were carried out using Kendrick plots. RESULTS:Numerous VDF telomer distributions were identified, each attributed to C6F13(C2H2F2)nI or C6F13(C2H2F2)nH, either in their deprotonated form or forming adducts or associations with I-, O2 •-, NO2 -, NO3 -, HCO2 -, HCO3 -, CO3 •-, and HCO4 -. The [M + HCO3]- and [M + HCO4]- anions were the most abundant, highlighting the crucial role of carbonate-linked anions in the DART ionization of PVDF. This observation was further supported by neutral losses corresponding to H2CO3 and H2CO4 in tandem mass spectrometry experiments. Furthermore, the oxidative properties of HCO4 - were emphasized. These results demonstrated the need to reinterpret data obtained in a previous DART-MS study on PVDF samples with unknown end groups. CONCLUSIONS:The complex and diverse ionization processes observed in the negative DART ionization of fluorinated telomers underline the need for careful data interpretation. The uncommon [M + HCO3]- and [M + HCO4]- adducts were found to play a significant role in the ionization of iodinated PVDF.

This review aims to present polytetrafluoroethylene (PTFE), its recent syntheses and processes, properties, applications, and its position in the per- and polyfluoroalkyl substances (PFAS) context. It is the most widely produced fluoropolymer, with production volumes increasing every year. In this review, this specialty polymer is described as endowing exceptional characteristics (chemical, thermal, UV, and aging resistance, waterproofness, rheological, mechanical, tribological, surface properties, and moisture vapor permeability). These outstanding features are well explained by numerous studies linking them to their crystallinity and packing structure, which are closely associated with a constantly evolving chemical synthesis process (fluorinated surfactants are no longer used nowadays). Moreover, the high molar mass of PTFE (several million g.mol-1) prevents its penetration through the human membrane, in addition to its insolubility in all solvents, non-toxicity, and non-bioaccumulation, showing its safe behavior (i.e., biocompatible) and Food and Drug Administration (FDA) approval. Furthermore, although considered a PFAS, this material meets the 13 Organization for Economic Co-operation and Development (OECD) polymer of low concern (PLC) criteria and, so far, is not subject to regulatory restrictions. Because of such features, PTFE can be used in many advanced applications satisfying stringent requirements (in terms of durability, safety, operational efficiency, and sustainability). Then, PTFE is a must-have material in the medical field and in transportation (aerospace, aircraft, railway, and automotive). It is also essential in electronics, the Internet of Things, clean energy storage and conversion, and other high-tech applications, making it an irreplaceable material in many areas of daily life.

Abstract Novel graft copolymers based on poly(vinylidene fluoride) (PVDF) bearing poly(2-alkyl-2-oxazoline) (POx) side chains, PVDF-g-POx, were synthesized via a two-step strategy. First, POx macromonomers end-functionalized with 2-(trifluoromethyl)acrylic acid (MAF-POx) were prepared through cationic ring-opening polymerization of 2-alkyl-2-oxazolines, followed by radical copolymerization with vinylidene fluoride (VDF). A series of MAF-POx macromonomers with number-average molar masses (Mn) ranging from 200 to 1200 g·mol–1 were successfully synthesized and characterized by 1H and 19F NMR spectroscopy as well as MALDI-TOF mass spectrometry. The subsequent graft (statistical) copolymerization was optimized by varying the [VDF]/[MAF-POx] initial molar ratio, the initiator type (peroxide or persulfate), and the reaction conditions. The incorporation of sodium trifluoromethanesulfinate enabled the introduction of CF3 end-groups, providing a useful probe for molar mass assessment by 19F NMR. The resulting PVDF-g-POx copolymers were obtained in yields reaching 62% and exhibited number-average molar masses up to 17,000 g·mol–1. The copolymer compositions were tunable via the feed ratio considering that VDF was more reactive than MAF-POx. Thermal analysis revealed that the incorporation of POx side chains slightly reduced the thermal stability compared to that of pristine PVDF. Differential scanning calorimetry highlighted melting temperatures ranging between 116 and 168 °C, depending on composition and molar mass, while the copolymers containing less than 70 mol % VDF were amorphous.

Direct analysis in real time (DART) was coupled with a thermal desorption/pyrolysis (TDPy) device for the analysis of fluoropolymers. The product ions were analyzed using a Fourier transform cyclotron resonance mass spectrometer (FT-ICR MS). Two different polyvinylidene fluoride (PVDF) samples were studied individually and in a 50/50 mixture. This study demonstrates the capability of TDPy DART FT-ICR MS to provide information on PVDF polymers, including the determination of end-groups and the detection of comonomers. The temperature program used enabled the desorption of the smallest oligomers (Mn approximate to 600 Da) below 400 degrees C, allowing for the identification of the end-groups, which ensured the differentiation of the PVDF. At temperatures above 400 degrees C, CwHxFy- ions were predominantly formed as a result of the thermal cleavage of the PVDF backbone. Specific pyrolysis products observed for one PVDF sample suggested the presence of 4.6 mol% hexafluoropropylene (HFP), as determined by NMR measurements. The molar percentage of HFP was also determined by a new approach using TDPy DART MS. The analysis of a 50/50 PVDF blend revealed species from both polymers during the thermo-desorption and pyrolysis events, confirming the ability of the proposed methodology to determine the mol% of the HFP comonomer. This represents the first TDPy DART FT-ICR MS study of fluoropolymers. Applicable to non-soluble or poorly soluble polymers, the proposed methodology enables the identification of end-groups, suggests the possibility of distinguishing fluoropolymers, and identifies blend composition. Additionally, the molar percentage of comonomers can be defined for poly(VDF-co-HFP) copolymers.

The radical emulsion copolymerization of vinylidene fluoride (VDF) with vinyl dimethylphosphonate (VDMP), affording original fluorophosphonate statistical copolymers that combine the robustness of fluoropolymers with the versatility of phosphonate functionalities is reported. The copolymerization proceeded efficiently under mild, aqueous conditions, yielding copolymers with high yields (up to 93%) and tunable compositions by adjusting the monomer feed ratios. The chemical structure and composition of the copolymers were thoroughly characterized by 1H, 19F, and 31P NMR spectroscopies, confirming successful incorporation of both comonomers, while MALDI-TOF mass spectrometry provided insight into the molar mass distribution and end-group functionalities. The resulting copolymers exhibited apparent number-average molar masses (Mn) in the range of 6600–11600 g·mol−1 with dispersities (Đ = 1.54–2.90), determined by SEC using poly(methyl methacrylate), PMMA, calibration standards. Thermal analysis reveals suitable thermal stability, with temperatures corresponding to the 10 wt% mass loss (Td10%) above 178 °C. Differential scanning calorimetry indicated that incorporation of VDMP units significantly modulates the crystalline structure of PVDF, leading to controlled crystallinity values ranging from 8 to 28% for VDF molar fractions of 45 to 94 mol%, respectively. Furthermore, post-polymerization hydrolysis of the phosphonate ester side groups provided a straightforward route to functionalized copolymers bearing phosphonic acid functionalities. This strategy establishes a versatile platform for multifunctional fluorophosphonate materials, suggesting potential future applications in coatings, flame retardants, binders for lithium-ion batteries, and fuel cell membranes, to be explored in forthcoming studies.

A novel sulfurated telechelic bis(methacrylate) monomer was synthesized and evaluated for its potential use in photopolymerization to yield gel polymer electrolytes (GPEs). The difunctional monomer was obtained via a two-step synthesis by the radical bismonoaddition of telechelic sulfurated dithiol onto allyl alcohol followed by the methacrylation of the resulting diol. It was prepared in 60% overall yield and thoroughly characterized by FTIR, Raman, and NMR spectroscopies. Several photopolymerizable formulations were then proposed by combining telechelic bis(methacrylate) with sodium bis(fluorosulfonyl)imide and tetraethylene glycol dimethyl ether. Upon UV initiation, a series of soft GPE films of various thicknesses were obtained and analyzed by FTIR spectroscopy. Their physicochemical, thermal, and preliminary electrochemical properties were then systematically studied. The resulting GPEs exhibit very low glass transition temperatures (-80 to -40 degrees C) and high electrical conductivity (1.2 x 10-4 Scm-1) at room temperature, with electrochemical stability up to 4.5 V vs. Na+/Na. Sodium plating-stripping experiments in Na/GPE/Na symmetric cells show stable polarization voltage curves with no significant fluctuations, indicating homogeneous sodium deposition and dissolution up to a current density of 0.2 mA/cm2. These preliminary and promising results support the potential application of the developed GPEs in sodium batteries.

Our ability to fully understand how plants acquire water and nutrients from the soil is constrained by the limitations of current technologies. Soil structures and properties are complex, dynamic, and profoundly modified by root and microbial secretions. Detailed descriptions of soil properties are rarely available to the researcher because natural soil is opaque, making direct observations challenging. To address these experimental difficulties, microcosm systems dedicated to live imaging of rhizosphere processes in highly controlled environmental conditions were developed. The system is based on fluorinated granular materials with low refractive indices, termed transparent soils. Microcosm chambers were assembled using poly(dimethyl siloxane) parts (PDMS) fabricated by injection moulding and subsequently joined to glass slides. The control of liquid fluxes in the microcosm was achieved by syringes passing through the PDMS parts or through custom made PDMS sponges. The platform was tested for live imaging experiments using Light Sheet Fluorescence microscopy. Results demonstrated that the platform is suitable for a diverse range of experiments, including live observation of plant roots, split-soil systems and investigations into the effects of soil heterogeneity, controlled water content experiments, and dye tracer monitoring. The technique was used to quantify the increase in infiltration rate due to the presence of roots in soil. This study demonstrates the potential of combining new materials and micro- fabrication techniques to overcome current limitations on plant-soil interaction research.

New fluoroboronated materials were obtained by chemical modification of poly-(VDF-co-MAF) copolymers synthesized by the radical copolymerization of vinylidene fluoride (VDF) with 2-(trifluoromethyl) acrylic acid (MAF). Two copolymers were first synthesized in dimethylcarbonate (DMC) or 1,1-difluoro-1-chloroethane as the solvents in 60% yields with molar masses of 22,000 and 12,000 g·mol-1, respectively. Although MAF does not homopolymerize under radical initiation, this is a suitable comonomer for VDF. The transfer rates were 0.40 and 0.21 for reactions carried out in DMC and in halogenated solvent, respectively. The resulting poly-(VDF-co-MAF) random copolymers were condensed with aminophenyl boronic acid pinacol ester (APBAPE) in the presence or absence of a HCl trap to obtain new fluoroboronated copolymer materials. Their 1H, 11B, 13C, and 19F NMR and ATR IR characterizations confirmed the successful addition of APBAPE onto the fluorinated copolymer. The thermal properties of all these original copolymers were determined. As expected, the thermal stability of poly-(VDF-co-MAF.APBAPE) copolymers displayed better behavior due to the decarboxylation of acid functions in MAF units as noted in their precursors. Such novel fluoropolymers bearing boron-containing groups may have potential applications in various areas as electronics and coatings.

Thanks to their exceptionally useful properties, fluoropolymers are irreplaceable materials involved in many High-Tech applications, such as aerospace, automotive, internet of things, optics and electronic industries. They are usually synthesized by radical (co)polymerization of fluoroalkenes under high pressure. While many radical initiators have been used, perfluoro-3-ethyl-2,4-dimethyl-3-pentyl persistent radical (PPFR) releases a trifluoromethyl radical, as well as sodium trifluoromethyl sulfinate, initiating the homopolymerization of vinylidene fluoride (VDF) or the copolymerization of VDF with a wide range of fluoroolefins. Among the latter, functional 2-trifluoromethacrylates (MAF-funcs) have shown characteristics leading to various materials such as anticorrosion coatings, gel polymer electrolytes for Lithium-ion batteries, and polymer exchange membranes for fuel cell. Finally, facing per- and polyfluoroalkyl substances (PFAS) issues, mineralizations of polyvinylidene fluoride (PVDF) and other VDF-containing copolymers were recently studied in subcritical water to generate fluoride anions, as an original source of CaF2, thus closing the loop of the fluorine chemistry.

Poly(VDF-co-VPA) copolymers were prepared via the free radical copolymerization of vinylidene fluoride (VDF) and vinylphosphonic acid (VPA). Solution polymerization of VDF with VPA in organic solvent was carried out in different reaction media and feed ratios to study the factors influencing such a copolymerization. Hydrophobic and hydrophilic fractions of the resulting copolymers were separated and purified from the total product mixture through filtration and dialysis, each of both revealing VDF-rich and VPA-rich copolymers, respectively. The presence of both comonomer units, functional groups, and molar mass of the resulting copolymers was characterized by 1H, 19F, and 31P NMR and Fourier-transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC) after methylation, as well as by matrix-assisted laser desorption/ionization (MALDI). Diffusion-ordered spectroscopy (DOSY) and 2D NMR characterization results further proved the formation of the random copolymers. The modified thermal behavior of the products monitored by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) corroborated VPA insertion (releasing much char at high temperature) into VDF units. The gradient copolymers not observed in the radical copolymerization of VDF with vinyl dimethylphosphonate may originate from the reactivity difference of VPA against VDF and its unique anhydride formation mechanism in the polymerization.

Hydrocarbon-based polymer electrolytes hold great promise for practical electrochemical device deployment but suffer from limitations such as ionic conductivity, alkaline stability, and hydrophobicity. This work reports a new membrane, LLDPE-g-1VIm/4VP, prepared by radiation grafting a binary mixture of 1-vinyl imidazole and 4-vinylpyridine onto linear low-density polyethylene. Short branches in LLDPE are hypothesized to regulate water uptake, thus improving dimensional stability. Under optimized conditions, the membrane exhibits a relatively high ionic conductivity of 39.86 mS cm-1 at 70 degrees C, good mechanical strength, improved dimensional stability, and moderate alkaline stability even after 240 h at 60 degrees C under harsh conditions. Preliminary evaluations demonstrate their potential as solid polymer electrolytes for electrochemical energy applications, including alkaline anion exchange membrane fuel cells.

We report a breakthrough strategy for recycling perfluorosulfonic acid (PFSA) polymers, such as Nafion, using tailored ionic liquids (ILs). Imidazolium- and phosphonium-based ILs enabled efficient dispersion of Nafion within 6 h at 180 degrees C, with performance increasing with IL hydrophobicity and alkyl chain length. Two sequential regimes were identified: initial cation exchange followed by IL diffusion enhanced by plasticization, ultimately driving membrane reorganization. Dispersion was triggered once the membrane volume expansion exceeds similar to 180%, underscoring strong IL-polymer affinity. Swelling kinetics deviated from Fickian behavior, indicating complex physicochemical interactions. Ethanol washing and acidification enabled partial IL removal and served as probes for IL localization and binding strength, as confirmed by FTIR. Multiscale structural analyses provide mechanistic insight: small-angle neutron scattering reveals pronounced swelling of ionic domains, while wide-angle X-ray scattering shows IL penetration into amorphous regions with irreversible rearrangements, with crystalline domains remaining preserved. Among the ILs tested, C1C8ImCl and P66614Cl offer the best compromise between dispersion efficiency and extractability. These findings highlight ILs as dual-function agents-both effective PFSA dispersants and potential functional additives-thus enabling high-yield recovery and upcycling of PFSA. This approach opens sustainable, closed-loop pathways for electrochemical energy technologies.

Per- or polyfluoroalkyl substances (PFASs) are man-made compounds which are involved in many consumable products. In recent years, after the deposition of a dossier by five member states, a project of PFAS restriction has been raised by US and European regulation agencies. Though certain are toxic, bioaccumulative and cross human cellular membranes, others, such as fluoropolymers, are safe, reliable, involved in many applications (high tech in which items undergo severe mechanical, thermal and stress conditions), fulfill the 13 polymer of low concern criteria and do not cross gastrointestinal membranes. This perspective focuses on a brief history on fluorochemicals, followed by the characteristics, properties and limitations of these products and fluoropolymers as well as recent information on regulations concerning PFASs. (c) 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Per- or polyfluoroalkyl substances (PFASs) are man-made compounds involved in compositions of many industrial processes and consumer products. The largest-volume man-made PFAS are made up of refrigerants and fluoropolymers. Major concerns for our society related to these substances are their contribution to global warming as greenhouse gasses and the potential for adverse effects on living organisms, particularly by long-chain perfluoroalkyl acid derivatives. Restrictions on manufacturing and applications will increase in the near future. The full remediation of historical and current contaminations of air, soil and water remains problematic, especially for ultra-short PFASs, such as trifluoroacetic acid. Future monitoring of PFAS levels and their impact on ecosystems remains important. PFASs have become integrated in the lifestyle and infrastructures of our modern worldwide society and are likely to be part of that society for years to come in essential applications by closing the fluorine loop.

This paper presents a study of the thermal and rheological properties of isosorbide, showing that its degradation temperature (around 100 °C) is much lower than values previously proposed in the literature. Furthermore, remarkable calorimetric and viscoelastic behaviors, with features usually observed in semi-crystalline systems are presented. The onset of the melting is measured at 45 °C, while a glass transition occurs at −45 °C, followed by cold crystallization. Wide-angle X-ray diffraction confirmed the coexistence of crystalline domains and an amorphous fraction, which behaves as a molecular glass, with an estimated crystallinity of approximately 70%. Thermogravimetric analyses conducted under both air and nitrogen and at multiple heating rates, in line with ICTAC recommendations, established the robustness of the 100 °C degradation onset. These findings provide new structure–property relationships for isosorbide and open up new avenues for further research and development in this area.

Abstract Per- or polyfluoroalkyl substances (PFASs) are man-made compounds involved in compositions of many industrial processes and consumer products. They are categorized into two main families based on their molar mass: though low molar mass products (<1000 Da) are toxic, mobile, bioaccumulable, and cross the human membranes, others of much higher molar masses, e.g., fluorinated macromolecules and especially fluoropolymers, are safe and reliable, do not face such concerns, do not cross the membranes (hence, they are regarded as Polymers of Low Concern), and are involved in many applications including medical products and high-value-added materials and devices. Because the former family has led to a severe global contamination, recent regulating agencies in Europe (REACH) and the USA (EPA) have aimed at restricting fluorochemicals. Recently, consultations from affected organisms and industries have led to more than 5600 answers and comments. This review supplies an update on the overall situation of PFASs, their limitations, regulations, end of life, degradations, and possible alternatives.