Perfluoromethyl Vinyl Ether Research Articles

Characteristics of perfluoromethyl vinyl ether: A new eco‐friendly alternative gas for SF6

AbstractThe exploration of eco‐friendly insulating gas to substitute the most potent greenhouse gas sulphur hexafluoride (SF6) has consistently garnered significant attention. Herein, the authors evaluated the feasibility of utilising perfluoromethyl vinyl ether (PMVE, C3F6O) as a new branch of eco‐friendly insulating gas for the first time. The primary dielectric and stability characteristics of PMVE regarding AC breakdown, partial discharge, dielectric recovery, and decomposition properties were revealed under various gas pressure and electrical field conditions. It was found that PMVE demonstrated superior dielectric strength, with the AC breakdown and PD inception voltage (PDIV) 1.10 and 1.14 times that of pure SF6. Furthermore, the dielectric strength of PMVE exhibits stability even after undergoing 100 cycles of AC breakdowns, and there is no observable formation of solid precipitation on the electrode surface. The discharge decomposition of PMVE mainly generates fluorocarbon (CF4, C2F6, C3F6, C3F8, etc.) and CO. Overall, the exceptional insulation stability and no absence of solid precipitation features endow PMVE to be utilised as a new eco‐friendly gas for SF6‐free gas‐insulated equipment.

Are (Co)Polymers of 1,1,3,3,3-Pentafluoropropene Possible?

The copolymerization and terpolymerization of 1,1,3,3,3-pentafluoropropene (PFP) with various combinations of fluorinated and hydrogenated comonomers were investigated. The chosen fluoromonomers were vinylidene fluoride (VDF), 3,3,3-trifluoropropene (TFP), hexafluoropropene (HFP), perfluoromethylvinyl ether (PMVE), chlorotrifluoroethylene (CTFE) and tert-butyl-2-trifluoromethacrylate (MAF-TBE), while the hydrocarbon comonomers were vinylene carbonate (VCA), ethyl vinyl ether (EVE) and 3-isopropenyl-α,α-dimethylbenzyl isocyanate (m-TMI). Copolymers of PFP with non-homopolymerizable monomers (HFP, PMVE and MAF-TBE) led to quite low yields, while the introduction of VDF enabled the synthesis of poly(PFP-ter-VDF-ter-M3) terpolymers with improved yields. PFP does not homopolymerize and delays the copolymerizations. All polymers were either amorphous fluoroelastomers or fluorothermoplastics with glass transition temperatures ranging from -56 °C to +59 °C, and they exhibited good thermal stability in air.

Atmospheric oxidation of unsaturated hydrofluoroethers initiated by OH radicals

Hydrofluoroethers (HFEs) are perfluorinated chemicals that were developed as alternative for chlorofluorocarbons (CFCs) in various applications. Among notable unsaturated HFEs are perfluoro methyl vinyl ether (PMVE, CF3OCFCF2) and perfluoro ethyl vinyl ether (PEVE, C2F5OCF = CF2). During the implementation of PMVE and PEVE, they spill and release to the atmosphere. Due to the tendency of perfluorinated compounds to have strong infrared absorption features and long atmospheric lifetimes, they are among the most potent greenhouse gases. Thus, it is important to accurately assess their atmospheric sink routes in order to assess their impact on climate change. Herein, we illustrated detailed mechanistic pathways and developed kinetic models with the underlying aim to comprehend the atmospheric fate of the title HFEs and the likely products of decomposition. It was found that the production of main products to stem from the addition of OH radical to the inner carbon-carbon double bond atoms. Atmospheric lifetimes of PMVE and PEVE were calculated to be ∼23 and ∼56 h; respectively. Time-dependent molar yields are acquired for the experimentally major products; namely carbonyl fluoride (CF2O), perfluorinated glyoxal (CFOCFO), perfluorinated methylformates (CF3OCFO and CF3CF2OCFO). Photochemical Ozone Creation Potentials (POCPs) of PMVE and PEVE were calculated to be 1.78 and 1.18, respectively. Obtained results tap into efforts that aim to understand the atmospheric chemistry cycles of perfluorinated chemicals in general.

Addition reaction of various azoles to perfluoromethyl vinyl ether

Addition reaction of various azoles to perfluoromethyl vinyl ether

Emulsion copolymerization of vinylidene fluoride (VDF) with perfluoromethyl vinyl ether (PMVE)

The radical emulsion copolymerization of vinylidene fluoride (VDF) with perfluoromethyl vinyl ether (PMVE), initiated by potassium persulfate in the presence or absence of a surfactant is presented.

Molecular–topological structure of tetrafluoroethylene–perfluoromethylvinyl ether copolymer irradiated with MeV protons

The molecular–topological structure of a copolymer of tetrafluoroethylene and perfluoromethylvinyl ether has been studied for the first time before and after irradiation with 1- and 4-MeV protons. The pseudo-network structure of the copolymer contains an amorphous block and crystalline segments of macromolecules as branching points. After bombardment with protons, a high-temperature amorphous block is formed in the copolymer with simultaneous complete amorphization of the copolymer structure and a decrease in its molecular flow temperature. The surface of a target plate with a thickness of 500 μm that has not been directly exposed to proton bombardment preserves the molecular–topological structure of the initial copolymer.

Glow-discharge radio frequency plasma polyether and fluoropolyether coated substrates prevent IgG protein adsorption

Event Abstract Back to Event Glow-discharge radio frequency plasma polyether and fluoropolyether coated substrates prevent IgG protein adsorption Marvin M. Mecwan1* and Buddy Ratner1* 1 University of Washington, Bioengineering, United States Introduction: Protein-based pharmaceuticals present unique challenges in processing, packaging and delivery. All proteins rapidly adsorb to solid surfaces, essentially irreversible, and frequently leads to denaturation or aggregation of the protein. Also, there are concerns with substances from the packaging leaching out and affecting proteins. This study examines fundamental aspects of protein interactions with surfaces, particularly using glow discharge plasma-treated surfaces which can be readily applied to delivery devices, packaging and processing equipment [1],[2] and may lead to a new generation of surfaces effective for protein manufacture, storage and delivery. This research particularly focuses on plasma tetraglyme (TG), acrylic acid (AA), perfluoropropylene (C3F6), and perfluoromethyl vinyl ether (C3F6O) plasma treated glass, stainless steel, and cyclic olefin polymer (COP) substrates and their interaction with IgG. Methods: Glass and COP (8mm φ discs), and 316L stainless steel (7 x 7 mm2) substrates were sequentially cleaned with DCM, acetone, and methanol in a sonication bath for 10 mins x 2. RF-Plasma deposition and delamination: Substrates were loaded into the reactor, and argon etched (40W for 5 min). Using a mass flow controller, the monomer of choice was introduced into the chamber and were plasma deposited. Plasma-treated samples (n=3/group) were washed using DI water x 3 over 24 hours to assess whether coatings would delaminate. ESCA analyses were done using an S-Probe ESCA (with monochromatic Al K-alpha X-rays focused to 800µm spot size) using survey and detailed C1s scans. Data was analyzed using ESCA analysis software. IgG adsorption studies: Bovine IgG was tagged using an ICl method. Plasma-treated samples (n=3/treatment group) were immersed in 0.1mg/mL I-125 tagged bovine IgG solution in 1x cPBS with sodium iodide (cPBSI) for 1 hr. Samples were rinsed with cPBS x 3 and counted for 10 mins using a gamma counter. Cytotoxicity studies: Plasma-coated samples were eluted in complete growth medium for 24 hrs (370C, 5% CO2­ incubator). ~80% confluent NIH-3T3 fibroblasts were exposed to eluates from the plasma coated substrates, and observed over 48 hrs using an inverted microscope. ISO 10993-5 guidelines were used for cytotoxic evaluation. Results and Discussion: ESCA scans of plasma-treated substrates showed absence of substrate associated peaks (such as Fe or Si), suggesting that coatings did not delaminate; also implies that plasma coatings on substrates are at least 10 nm thick (ESCA resolution is 100Å). Furthermore, experimental and theoretical elemental compositions of the surfaces align well. Protein adsorption studies show that tetraglyme and acrylic acid plasma coatings are essentially non-fouling (<2 ng/cm2) as compared to C3F6 and C3F6O plasma coatings which adsorbed proteins in the range of 10-14 ng/cm2. Furthermore, all plasma treated substrates show reduced protein adsorption compared to untreated controls. Moreover, fibroblasts exposed to all plasma coating eluates remained viable after 48 hours. Conclusions: The data demonstrate that plasma-treated polyether and fluoropolyether substrates can create a new generation of surfaces that can be used for contact with protein therapeutic agents.Future studies will be aimed at investigating the strength of bonding of IgG to these surfaces, as well as protein aggregation studies. Winston Ciridon; Xia Dong, PhD

Theoretical study of the OH-initiated atmospheric oxidation mechanism of perfluoro methyl vinyl ether, CF₃OCF=CF₂.

Product formation in the reaction of perfluorinated methyl vinyl ether, CF3OCF=CF2, with OH radicals is studied theoretically using the M06-2X/aug-cc-pVTZ and CCSD(T) levels of theory. The stable end-products in an oxidative atmosphere are predicted to be perfluorinated methyl formate, CF3OCFO, and fluorinated glycolaldehyde, CFOCF2OH, both with CF2O as coproduct. The prediction of glycolaldehyde as a product contrasts with experimental data, which found perfluoro glyoxal, CFOCFO, instead. The most likely explanation for this apparent disagreement is conversion of CFOCF2OH to CFOCFO, e.g. by multiple catalytic agents present in the reaction mixture, wall reactions, and/or photolysis. The formation routes for the glyoxal product proposed in earlier work appear unlikely, and are not supported by theoretical or related experimental work.

Recent advances in the controlled radical (co) polymerization of fluoroalkenes and applications therefrom

Since late 1970s, extensive studies on controlled (or pseudoliving) radical polymerizations (CRP) have been reported, especially from mid-1990s. Though many works have been investigated, the unexpected scientific growth of CRP contrasts with few commercially available products derived from these techniques. But, for fluoropolymers, the situation appears reversed since iodine transfer polymerization of fluoroalkenes already yielded commercially available thermoplastic elastomers as soon as 1984. These proceedings display a brief overview or CRP of fluorinated monomers (with a real challenge for gaseous fluoroalkenes such as vinylidene fluoride, chlorotrifluoroethylene, 3,3,3-trifluoropropene, hexafluoropropylene, perfluoromethyl vinyl ether). These monomers can be (co)polymerized via the iodine transfer polymerization or from techniques that involve either borinates or xanthates (named MADIX). These technologies enable one to generate copolymers that exhibit well-defined architectures, such as telechelic, block and graft copolymers and open up High Tech applications such as potentially non-bioaccumulable surfactants, elastomers endowed with low Tgs and that can be crosslinked, thermoplastic elastomers which can be used in a wide range of temperatures, fuel cell membranes being processed either by casting or by reactive extrusion.

Kinetics and mechanism for synthesis of iodo-containing telomeres and block copolymers at high pressures

Radical telomerization reactions of hexafluoropropylene, perfluoromethyl vinyl ether, and perfluoropropyl vinyl ether in the presence of alkyl iodides were studied at high pressures (1000 MPa). Iodo- and diiodo-containing telomeres were synthesized. Their preparation is almost impossible under usual conditions. The mechanism and kinetics of telomerization were studied. Block copolymers of different structures were synthesized from the obtained telomeres by the “living” radical telomerization method.

Synthesis and Characterizations of Photo-Cross-Linkable Telechelic Diacrylate Poly(vinylidene fluoride-co-perfluoromethyl vinyl ether) Copolymers

Novel telechelic primary dihydroxyl and diacrylate cooligomers based on vinylidene fluoride (VDF) and perfluoromethyl vinyl ether (PMVE) were synthesized as precursors of original photo-cross-linkable networks. First, α,ω-diiodopoly(VDF-co-PMVE) copolymers were generated by iodine transfer copolymerization of VDF and PMVE controlled by 1,4-diiodoperfluorobutane chain transfer agent, leading to cooligomers with molecular weights ranging between 1,500 and 7,000 g·mol–1 with a narrow polydispersity (<1.3). Then, two major approaches were applied to obtain telechelic poly(VDF-co-PMVE) diols as precursors of α,ω-diacrylates that contained spacers of various lengths between the hydroxyl (or ester) functions and the poly(VDF-co-PMVE) oligomeric chain. The first strategy involved a quantitative ethylene end-capping of telechelic diiodo poly(VDF-co-PMVE) cooligomers and subsequent hydrolysis to form diols with one ethylene spacer (C2). The second route to obtain fluorinated macrodiols involved the radical addition...

Synthesis and characterization of original alternated fluorinated copolymers bearing glycidyl carbonate side groups

AbstractA vinyl ether bearing a carbonate side group (2‐oxo‐1,3‐dioxolan‐4‐yl‐methyl vinyl ether, GCVE) was synthesized and copolymerized with various commercially available fluoroolefins [chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), and perfluoromethyl vinyl ether (PMVE)] by radical copolymerization initiated by tert‐butyl peroxypivalate. Although HFP, PMVE, and vinyl ether do not homopolymerize under radical conditions, they copolymerized easily yielding alternating poly(GCVE‐alt‐F‐alkene) copolymers. These alternating structures were confirmed by elemental analysis as well as 1H, 19F, and 13C NMR spectroscopy. All copolymers were obtained in good yield (73–85%), with molecular weights ranging from 3900 to 4600 g mol−1 and polydispersities below 2.0. Their thermogravimetric analyses under air showed decomposition temperatures at 10% weight loss (Td,10%) in the 284–330°C range. The HFP‐based copolymer exhibited a better thermal stability than those based on CTFE and PMVE. The glass transition temperatures were in the 15–65°C range. These original copolymers may find potential interest as polymer electrolytes in lithium ions batteries. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Gas transport and free volume in hexafluoropropylene polymers

Amorphous perfluorinated polymers reveal interesting gas permeation and sorption properties. However, the number of the polymers of this class described in literature is limited. In this work, synthesis and physicochemical properties of two novel perfluorinated polymers: poly(hexafluoropropylene) (PHFP) and the copolymer of hexafluoropropylene (90 wt.%) and perfluoromethylvinyl ether (10 wt.%) (copoly-HFP–PFMVE) are reported. PHFP and copoly-HFP–PFMVE are completely amorphous polymers with T g of 150 and 142 °C, respectively. PHFP exhibits a relatively high gas permeability ( P(O 2) = 124 Barrer) and so the gas permeation properties are intermediate between those of AF1600 and Hyflon copolymers. As is the case for other perfluorinated polymers, the data points of PHFP and copoly-HFP–PFMVE are located above upper bounds (1991) of Robeson diagrams for He/H 2 and He/CH 4 pairs. Enhanced selectivity of separation of these pairs as well as for N 2/CH 4 separation can be explained by reduced permeability and solubility of hydrogen containing molecules in perfluorinated polymers. Positron annihilation lifetime spectroscopy showed monomodal size distribution of free volume in these polymers with the concentration of microcavities of about 6–7 × 10 20 cm −1 and the corresponding average size of 392 and 364 Å 3 in PHFP and copoly-HFP–PFMVE, respectively. Solubility and diffusivity selectivity in the two novel polymers are compared to those reported for other perfluorinated polymers.

Kinetic regularities and mechanism of polymerization of perfluoromethylvinyl ether at high pressures

The kinetics of the thermal polymerization of perfluoromethylvinyl ether (PFMVE) is studied at pressures of 3–13 kbar (300–1300 MPa) and temperatures of 80–260°C. The activation energy (Eact = (76 ± 3) kJ/mol) and activation volume (ΔV0⪼ = −(27 ± 2) cm3/mol) for the overall polymerization rate are determined. The inhibition method is used to estimate the activation energy of thermal initiation (Ein = (79.9 ± 3) kJ/mol). The quantity Ep − (1/2)Et was calculated to be 36.6 ± 3 kJ/mol. The limiting polymerization temperature was evaluated: Tlim = (180 ± 3)°C. A mechanism of PFMVE polymerization is proposed on the assumption that the reaction is bimolecular.

Telechelic Diiodopoly(VDF-co-PMVE) Copolymers by Iodine Transfer Copolymerization of Vinylidene Fluoride (VDF) with Perfluoromethyl Vinyl Ether (PMVE)

The synthesis and the characterization of fluoroelastomers, based on vinylidene fluoride (VDF) and perfluoromethyl vinyl ether (PMVE), poly(VDF-co-PMVE) copolymers, by iodine transfer copolymerization are presented. These statistic poly(VDF-co-PMVE) copolymers were prepared in the presence of a perfluoromonoiodo functional chain transfer agent (CTA), C6F13I, or telechelic diiodoperfluoroalkane CTAs, IC6F12I and IC4F8I, using an emulsion process without any surfactant. Quasi-optimal conditions were found to lead to poly(VDF-co-PMVE) copolymers in satisfactory yields. The copolymer compositions, the molecular weights, and end-groups of these random-type copolymers were assessed by means of 19F NMR spectroscopy. Model molecules containing only one PMVE unit were synthesized by the radical addition of different CTAs (ICl, ICF2I, CF3I) onto PMVE to help in the assignments by 19F NMR spectroscopy of the characteristic signals of the end-group, i.e., −CF2CF(OCF3)I and −CF(OCF3)CF2I. Indeed, only −CH2CF2−I (major amount) and −CF2CH2−I end-groups of these poly(VDF-co-PMVE) copolymers were noted, showing the high reactivity of PMVE−I in the iodine transfer polymerization of VDF. The CTA concentration enabled one to control the molecular weights of the resulting telechelic diiodopoly(VDF-co-PMVE) copolymers ranging from 1000 to 18 000 g mol−1 (assessed by 19F NMR), produced for the first time. It was also noted that the higher the molar masses, the higher the amount of −CF2CH2−I end-group. The controlled behavior of that polymerization was also evidenced by the absence of the reversed −CH2CF2−CF2CH2− VDF dyads, narrow polydispersity indices (<1.75), and the linear “molar mass versus monomer conversions” relationship. Finally, the thermal properties, i.e., the glass transition temperatures (Tg) and degradation temperatures, of these copolymers were assessed and were found to depend on the molecular weights and on the monomer composition of the copolymers. These fluoroelastomers had Tgs ranging from −63 to −35 °C according to their molecular weights and the contents of both comonomers, with decomposition temperatures greater than 250 °C under air.

Synthesis of fluorine-containing benzimidazole derivatives

Various fluorine-containing benzimidazoles were obtained by the reaction of o-phenylene-diamine, 3,4-diaminotoluene, and 1,2-diamino-4-chlorobenzene with hexafluoropropene or perfluoro(methyl vinyl ether) in DMF. A new efficient method of synthesis of 2-(1,2,2,2-tet-rafluoroethyl)benzimidazole by the reaction of o-phenylenediamine with hexafluoropropene in the presence of diethylamine or dimethylamine in ethyl acetate is developed.

Synthesis and characterization of perfluoro‐3‐methylene‐2,4‐dioxabicyclo[3,3,0] octane: Homo‐ and copolymerization with fluorovinyl monomers

AbstractThe synthesis of perfluoro‐3‐methylene‐2,4‐dioxabicyclo[3,3,0] octane (D), its radical homopolymerization, and copolymerization with fluoroolefins are presented. Fluorodioxolane (D) was synthesized through direct fluorination of the corresponding hydrocarbon precursor in a fluorinated solvent by F2/N2 gas. It was polymerized in bulk using perfluorodibenzoyl peroxide as the initiator. The resulting homopolymer had a limited solubility in fluorinated solvents, and its glass transition temperature (Tg) was in the range of 180–190 °C. The polymeric films prepared by casting from hot hexafluorobenzene (HFB) solution were transparent with low refractive index (1.329 at 633 nm). These films were thermally stable (Td &gt; 350 °C), and were hard and brittle. The copolymers of monomer (D) were prepared with fluorovinyl monomers such as chlorotrifluoroethylene (CTFE), perfluoropropyl vinyl ether, perfluoromethyl vinyl ether, and vinylidene fluoride. The kinetics of radical copolymerization of monomer (D) with CTFE led to the assessment of the reactivity ratios of both comonomers: rD = 3.635 and rCTFE = 0.737 at 74 °C, respectively. The copolymers obtained were soluble in HFB and perfluoro‐2‐butyltetrahydrofuran, with Tg in the range of 84–145 °C depending on the copolymer composition. The films of the copolymers were flexible and clear with a low refractive index (1.3350–1.3770 at 532 nm). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6571–6578, 2009

From Vinylidene Fluoride (VDF) to the Applications of VDF-Containing Polymers and Copolymers: Recent Developments and Future Trends

After an introduction reporting the properties and the applications of fluoropolymers, a first part deals with i) the main routes to produce vinylidene fluoride (VDF) monomer, ii) its homopolymerization, and iii) the advantages and uses of polyvinylidene fluoride (PVDF). In a second section, this review, illustrated by numerous examples, extensively reports the synthesis, properties and applications of the copolymers based on VDF with non-halogenated, fluorinated, commercially available or synthesized comonomers. These comonomers exhibit XYC=CZ-Sp-R structures where X, Y, and Z represent H, F, and CF3 groups, Sp a spacer and R a function such as OH, OAc, SAc, CO2R' (R' being a H atom or an alkyl group), CN, P(O)(OR')2 and SO3H. According to the nature and to the amount of the comonomer, the copolymers can be thermoplastic, elastomeric or thermoplastic elastomers. Introducing reactive R side groups brings complementary properties such as hydrophily, ionic exchange or surface properties, or further crosslinking of the resulting copolymers. Then, the kinetics of radical copolymerization of VDF with M comonomers led to the assessment of the reactivity ratios which are compared. Hence, a reactivity series of these M comonomers with respect to a macroradical terminated by VDF is proposed. Usually, these copolymers exhibit random structures but only three comonomers produced alternating copolymers with VDF: hexafluoroisobutylene, F2C=CFCO2CH3, and H2C=C(CF3)CO2R. The controlled radical copolymerizations of VDF with other comonomers (such as chlorotrifluoroethylene, 3,3,3-trifluoropropene, hexafluoropropylene, perfluoromethyl vinyl ether or-trifluoromethacrylic acid) either in the presence of xanthates, borinates or iodo-compounds are also reported. In addition, new VDF-containing copolymers exhibit well-defined architectures, such as block and graft copolymers. They can be synthesized either by conventional techniques or by controlled radical copolymerization. Chemical modifications of PVDF and poly(VDF-co-monomer) copolymers are also presented. Several properties and applications (such as surfactants, dielectrical polymers, thermoplastic elastomers, fuel cell and ultrafiltration membranes, or polycondensates, the fluorinated segments of which bringing softness and thermal stability) of these VDF-containing copolymers will illustrate this review.

Synthesis of perfluoro(methyl vinyl ether) polymer at high pressures

Polymer of perfluoro(methyl vinyl ether) was synthesized for the first time. Polymerization was carried out at pressures from 300 to 1500 MPa and temperatures from 80 to 200 °C. The polymer synthesized is elastic, transparent, and soluble in perfluorobenzene, perfluorodecalin, and other perfluorinated solvents. The intrinsic viscosity of the polymer reaches 2 dL g s-1 . The study of the thermal stability on a derivatograph showed that the weight loss of the polymer sample occurred at 372 °C, being 0.1%.

Effective thermal conductivity behavior of filled vulcanized perfluoromethyl vinyl ether rubber

AbstractThe effective thermal conductivity behavior of vulcanized perfluoromethyl vinyl ether (PMVE) rubber filled with various inorganic fillers was investigated and analyzed with thermal conductivity models. Experimental results showed that there was no significant improvement in the thermal conductivity of PMVE rubber if the intrinsic thermal conductivity of the fillers was greater than 100 times that of the rubber matrix, and this agreed with the prediction of Maxwell's equation. The thermal conductivity of PMVE rubber filled with larger size silicon carbide (SiC) particles was greater than that of PMVE filled with smaller size SiC because of the lower interfacial thermal resistance, and there existed a transition filler loading at about 60 vol %. It was also found that flocculent graphite was the most effective thermally conductive filler among the fillers studied. A modified form of Agari's equation with a parameter independent on the units used was proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008