Abstract: Disclosed herein is a crosslinked fluoropolymer network formed by the free radical initiated crosslinking of a diacrylate fluoropolymer The diacrylate copolymer is of formula CH2?CR?COO—(CH2)n—R—(CH2)n—OOCR??CH2, wherein R is selected from the group consisting of i) an oligomer comprising copolymerized units of vinylidene fluoride and perfluoro(methyl vinyl ether), ii) an oligomer comprising copolymerized units of vinylidene fluoride and hexafluoropropylene, iii) an oligomer comprising copolymerized units of tetrafluoroethylene and perfluoro(methyl vinyl ether), and iv) an oligomer comprising copolymerized units of tetrafluoroethylene and a hydrocarbon olefin, R? is H or —CH3, n is 1-4 and wherein said oligomer has a number average molecular weight of 1000 to 25,000 daltons. The source of the free radicals may be a photoinitiator or an organic peroxide.

Abstract: The invention pertains to a multi-phase thermoplastic fluoropolymer composition, comprising a thermoplastic fluoropolymer and discrete domains of melt-processable perfluoropolymer, to the articles therefrom and to a process for manufacturing thermoplastic fluoropolymer compositions. The multi-phase thermoplastic fluoropolymer composition comprises: —at least one thermoplastic fluoropolymer (A); and —from 0.1 to 10% by weight of (A) of at least one melt-processible perfluoropolymer (B), and is characterized in that the polymer (B) is present in the composition in phase-separated domains in a continuous phase mainly comprising (A), at least 75% by volume of said domains having maximal dimension not exceeding 1 ?m. The process of the invention comprises mixing: (i) a thermoplastic fluoropolymer (A); (ii) a melt-processible perfluoropolymer (B) under the form of particles having an average primary particle size not exceeding 300 nm; (iii) and optionally other additives or filling materials.

Abstract: To provide an aqueous polytetrafluoroethylene (PTFE) emulsion which does not substantially contain ammonium perfluorooctanoate, and which is obtained by emulsion polymerization. Further, to provide a PTFE fine powder which is obtained from the aqueous PTFE emulsion and is excellent in a paste extrusion processability, and a porous material. An aqueous polytetrafluoroethylene emulsion obtained by carrying out emulsion polymerization of tetrafluoroethylene alone or together with another copolymerizable monomer in an aqueous medium, wherein a fluorinated emulsifier of the formula (1): CF2CF2(O)mCF2CF2OCF2COOA wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NH4, and m is an integer of 0 or i, is used in an amount of from 1,500 to 20,000 ppm, based on the final yield of polytetrafluoroethylene.

Abstract: The present invention relates to a process for chemically modifying, within its thickness, a polymer matrix chosen from matrices made of fluoropolymers and matrices made of aliphatic polymers, said process comprising at least one step consisting in irradiating said matrix with UV light having a wavelength of less than 300 nm in order to generate, within the thickness of said matrix, zones that have short polymer chains, formed by scission of the existing chains during the passage of the UV radiation and that have free radicals denoted hereinbelow as “activated zones”. The present invention also relates to the polymer matrix capable of being chemically modified by such a process.

Abstract: that are made up of oriented polymer chains are provided. Chains of polymer may be oriented or substantially aligned in one or more directions exhibiting enhanced thermal conductivity along the direction of orientation. Orientation of polymers within sheets may lead to a wide range of thermally relevant applications.

Abstract: The present invention provides a vinyl fluoride copolymer comprising: about 40 to about 90 mole % of repeat units derived from vinyl fluoride; and about 10 to about 60 mole % of repeat units derived from monomer selected from the group consisting of (a) and (b) below and mixtures thereof, with the proviso that about 0.1 mole % to 50 mole % of repeat units in the copolymer are derived from monomer selected from (b): (a) monomer selected from the group consisting of, tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene and mixtures thereof; and (b) vinyl monomer containing at least one functional group selected from the group consisting of hydroxyls, thiols, carbonyls, carboxylic acids, carboxylic esters, acid anhydrides, sulfonyls, sulfonic acids, sulfonic esters, phosphoric acids, phosphoric esters, boric acids, boric esters, epoxies, isocyanates, thiocyanates, amines, amides, nitriles and halogen selected from bromide and iodide.

Abstract: Chain end functionalized fluoropolymers are disclosed exhibiting good chemical reactivity high breakdown electric field (E>100 MV/m) and high dielectric constants (i.e., ?>10). The polymers can be prepared by functional initiators and from a variety of fluoromonomers including vinylidene difluoride together with one or more additional monomers. The polymers can be combined with other dielectric materials to form composites having uniform composition and morphology.

Abstract: To provide a process for producing a thermoplastic fluororesin having a high melt tension and being excellent in blow moldability, etc.

Abstract: An adhesive vinylidene fluoride resin sheet, including: an extruded sheet of a vinylidene fluoride copolymer composition comprising 100 wt. parts of polymerized units of a vinylidene fluoride monomer containing at least 60 wt. % of vinylidene fluoride, and 0.01-0.8 wt. part of polymerized units of a monoester of unsaturated dibasic acid. The vinylidene fluoride resin sheet is excellent in adhesiveness with another thermoplastic resin layer, and provides a lamination extrusion sheet with such another thermoplastic resin layer taking advantage of the good adhesiveness.

Abstract: The present invention provides an ethylene/tetrafluoroethylene copolymer composition having a high melt flowability while maintaining satisfactory mechanical properties in the obtainable molded product are maintained. The ethylene/tetrafluoroethylene copolymer composition (C) has a melt viscosity of from 80 to 500 Pa·s, preferably from 100 to 300 Pa·s and a tensile elongation of from 200 to 500%, preferably from 350 to 450%. The copolymer composition (C) is may be obtained by melt kneading an ethylene/tetrafluoroethylene copolymer (A) having a low melt viscosity of from 60 to 400 Pa·s, preferably from 80 to 300 Pa·s and an ethylene/tetrafluoroethylene copolymer (B) having a melt viscosity higher than this i.e. from 600 to 10,000 Pa·s, preferably from 1,000 to 7,000 Pa·s in a mass ratio of (A)/(B)=50/50 to 99/1, preferably (A)/(B)=60/40 to 97/3.

Abstract: The invention provides a TFE polymer capable of providing stretched materials excellent in membrane homogeneity. The present invention is related to a tetrafluoroethylene polymer having stretchability and non-melt-processability and having a standard specific gravity of 2.140 to 2.165, wherein, with regard to the heat-of-fusion curve obtained by subjecting the tetrafluoroethylene polymer in the form of an unbaked polymer to be measured having no history of being heated to a temperature of 300° C. or higher to differential scanning calorimetry at a programming rate of 2° C./minute, the ratio S2/S1 is not lower than 0.90.

Abstract: Fluoroelastomer gum or crumb is isolated from fluoroelastomer dispersions by the addition of a water-soluble polymeric coagulating agent to the dispersion. This coagulating agent comprises either a homopolymer of ethylene oxide (CH2CH2O—) or a copolymer of ethylene oxide. Specific examples of such copolymers include, but are not limited to ethylene oxide-propylene oxide copolymers and ethylene oxide-butylene oxide copolymers. The viscosity average molecular weight (Mv), determined by rheology, of the coagulant polymer must be at least 500,000 and preferably greater than 2,000,000.

Abstract: Described herein are nitric oxide (NO)-donating poly(tetrafluoroethylene) (PTFE) polymers and polymer surfaces and methods of making and using the same. The NO-donating PTFE polymers can be used to fabricate at least a portion of an implantable medical device, coat at least a portion of an implantable medical device or form at least a portion of an implantable medical device. The NO-donating PTFE polymers provide controlled release of NO once implanted at or within the target site.

Abstract: A functional TFE copolymer fine powder is described, wherein the TFE copolymer is a polymer of TFE and at least one functional comonomer, and wherein the TFE copolymer has functional groups that are pendant to the polymer chain. The functional TFE copolymer fine powder resin is paste extrudable and expandable. Methods for making the functional TFE copolymer are also described. The expanded functional TFE copolymer material may be post-reacted after expansion.

Abstract: A process for the preparation of a fluoroolefin polymer, including the step of: contacting in a reaction zone: an initiator; CF3CF?CH2, and optionally, at least one ethylenically unsaturated comonomer capable of copolymerizing therewith; wherein the contacting is carried out at a temperature, pressure and length of time sufficient to produce the fluoroolefin polymer.

Abstract: A process for producing fluoropolymers by polymerizing at least one fluorinated monomer in a polymerization medium comprising water and selected low-telogenic hydrofluoroethers (HFEs).

Abstract: In order to produce a carrier foil for printed circuit boards, which is particularly suitable for high component densities, it is proposed that said carrier foil be produced from a polymer material comprising a thermoplastically processable, substantially fully fluorinated plastics material.

Abstract: The present invention relates to a method of producing an electret material, to a new class of electret materials and to a device comprising such electret materials.

Abstract: The present invention provides an aqueous dispersion of a low-molecular-weight polytetrafluoroethylene (PTFE), which contains an easily removable surfactant, and has a good dispersion stability. Specifically, the present invention provides an aqueous dispersion of a low-molecular-weight PTFE comprising tetrafluoroethylene (TFE) units, or TFE units and modifying monomer units which are copolymerizable with the TFE units, wherein the aqueous dispersion contains from 70 to 9,000 ppm, based on the aqueous dispersion, of a fluorine-containing compound of the formula (1) below: X—(CF2)m—Y??(1) where X is H or F; m is an integer from 3 to 5; and Y is —SO3M, —SO4M, —SO3R, —SO4R, —COOM, —PO3M2 or —PO4M2, M being H, NH4 or an alkali metal, and R being an alkyl group having 1 to 12 carbons, and the low-molecular-weight PTFE has an average primary particle size of from 100 to 350 nm.

Abstract: The present invention provides a method for producing a PTFE fiber that makes it possible, unlike the emulsion spinning process, to obtain a polytetrafluoroethylene (PTFE) fiber, particularly a long PTFE fiber, without using a matrix material, is more productive than conventional production methods such as a slit yarn process, and is capable of enhancing mechanical properties and the degree of freedom in diameter of the obtained fiber. The method for producing the PTFE fiber of the present invention includes the step of reducing a diameter of a string-shape PTFE-containing solid material (a first solid material) by drawing the first solid material at a temperature equal to or higher than a melting point of PTFE. The first solid material can be obtained from a PTFE-containing solid material (a second solid material) containing water and a surfactant, by reducing an amount of the water contained in the second solid material.

Abstract: To provide an ETFE-type copolymer having a high melt tension and excellent blow moldability. An ethylene-tetrafluoroethylene copolymer which comprises ethylene units, tetrafluoroethylene units and units of a monomer (A) having at least two copolymerizable double bonds and which has a ratio (X/W) of its melt tension (XmN) to a load (Wkg) applied for the measurement of the melt tension being at least 0.8.

Abstract: VDF-based curable fluoroelastomers, having a glass transition temperature lower than ?49° C., preferably lower than ?50° C., and having the following composition, as percent moles: A) from 25% to 50%, preferably from 30% to 45%, of the monomer of formula: CF2?CFOCF2OCF3 (a); B) one or more (per)fluorinated comonomers having at least one unsaturation of ethylene type in amounts from 75% to 50%; preferably from 70% to 55%; said one or more comonomers comprising vinylidene fluoride (VDF) in amounts from 50% to 75% on the total of the monomer moles; the sum of the molar percentages of the monomers being 100%; said fluoroelastomers containing an amount of —COF end groups in the polymer lower than the sensitivity limit of the method reported in the description.

Abstract: Method for recovering a polymer from a liquid medium (1) substantially containing the polymer and a solvent for the latter, wherein: (a) this liquid medium (1) is injected into a reactor (2) containing a stirred substantially monophase liquid mixture comprising a major fraction by weight of a non-solvent and a minor fraction by weight of a solvent, the mixture having a composition and temperature such that the polymer precipitates therefrom progressively; (b) the polymer is recovered in the form of particles in suspension (5) in a liquid rich in non-solvent; (c) the polymer particles (9) are separated from the liquid.

Abstract: A process of removing fluorinated compounds from an aqueous phase originating from the preparation of fluoropolymers said process comprising the use of polycationic polymers.

Abstract: Fluoroalkyl amidoalkyl alcohols of the formula are disclosed and their corresponding (meth)acrylate esters. These fluoroalkyl amidoalkyl (meth)acrylate monomers can be copolymerized with a wide variety of conventional ethylenically unsaturated monomers. The resulting copolymers are useful as water, oil- and grease-proofing agents for paper, textiles and hard surfaces such as masonry and wood.

Abstract: A composition comprising a copolymer having repeating units in any sequence of Formula I wherein Rf is a straight or branched perfluoroalkyl group having from about 1 to about 20 carbon atoms, or a mixture thereof, which is optionally interrupted by at least one oxygen atom, X3 is oxygen or X1, each X1 is independently an organic divalent linking group having from about 1 to about 20 carbon atoms, optionally containing an oxygen, nitrogen, or sulfur, or a combination thereof, G is F or CF3, A is an amide, j is zero or positive integer, X2 is an organic linking group, Y is O, N or S, h is zero when Y is N, and h is one when Y is O or S, Z is H, a straight or branched alkyl group having from about 1 to about 4 carbon atoms, or halide, B is H or wherein Rf, X1, X3, G, A, and j are as defined above, provided that when B is H, j is a positive integer, m is a positive integer, q is zero or a positive integer when Y is O, and q is a positive integer when Y is N or S, p is zero or a positive integer

Abstract: Fluoroalkyl amidoalkyl alcohols of the formula are disclosed and their corresponding (meth)acrylate esters. These fluoroalkyl amidoalkyl (meth)acrylate monomers can be copolymerized with a wide variety of conventional ethylenically unsaturated monomers. The resulting copolymers are useful as water, oil- and grease-proofing agents for paper, textiles and hard surfaces such as masonry and wood.

Abstract: A method of manufacturing, by suspension polymerization, dielectric copolymers, including injecting an initial mixture of constituent monomers into an autoclave at constant temperature and pressure, wherein the mixture of constituent monomers including vinylidene difluoride (VDF), trifluoroethylene (TrFE), and a monomer 2 to 10 times more reactive than VDF and TrFE; and continuously reinjecting at constant pressure, as soon as the reaction is initiated and throughout the duration of polymerization, a second mixture of the constituent monomers, wherein the molar composition of the initial mixture and the second mixture are determined by calculation, in a manner known of itself, taking into account the desired molar composition of the copolymer and the higher reactivity of the third monomer.

Abstract: The present invention provides an aqueous emulsion resin composition which comprises: (a) a resin composition containing at least one fluoroolefin polymer having crosslinkable group(s) at a terminus and/or a side chain of its molecule and at least one non-fluoroolefin polymer having crosslinkable group(s) at a terminus and/or a side chain of its molecule; and (b) at least one curing agent selected from the group consisting of isocyanates, melamines, hydrazides, carbodiimides, silanes and epoxides; and provides an aqueous emulsion resin compositions containing at least one chemically bonded product of a fluoroolefin polymer and a non-fluoroolefin polymer bonded to each other via at least one covalent bond at a terminus and/or a side chain of the molecules wherein one or both of the fluoroolefin polymer and the non-fluoroolefin polymer have crosslinkable group(s).

Abstract: Polyfluorinated carboxylic acids and their salts containing an ethylene-tetrafluoroethylene moiety, which are useful as surfactants in a process for the dispersion polymerization of fluorinated monomer in an aqueous polymerization medium.

Abstract: Interpolymers of 1-99 mol % vinyl fluoride and 99-1 mol % of at least one highly fluorinated monomer such as tetrafluoroethylene are disclosed. The interpolymers are characterized by the presence of ionic end groups and are prepared by polymerizing VF and fluorinated monomer in water with water-soluble free-radical initiators such as azoamidine initiators or persulfate initiators at temperatures within the range of 60 to 100° C. and reactor pressures within the range of 1 to 12 MPa (145 to 1760 psi). The invention further provides for protective self-supporting films and coatings formed from nonaqueous dispersions of the interpolymers, both for use on the surfaces of substrates including metal, plastic, ceramic, glass, concrete, fabric and wood.

Abstract: A process for separating tetrafluoroethylene from a mixture comprising tetrafluoroethylene and carbon dioxide by contacting the mixture with at least one ionic liquid.

Abstract: The present invention pertains to a linear semi-crystalline copolymer [polymer (A)] comprising recurring units derived from vinylidene fluoride (VDF) monomer and at least one hydrophilic (meth)acrylic monomer (MA) of formula (I) wherein each of R1, R2, R3, equal or different from each other, is independently an hydrogen atom or a C1-C3 hydrocarbon group, and ROH is a hydrogen or a C1-C5 hydrocarbon moiety comprising at least one hydroxyl group, said polymer (A) comprising from 0.05 to 10% by moles of recurring units derived from said hydrophilic (meth)acrylic monomer (MA) and being characterized by a fraction of randomly distributed units (MA) of at least 40%, having improved thermal stability, to a process for its manufacture, to a composition comprising the same, and to its use as binder in batteries or for the manufacture of hydrophilic membranes.

Abstract: An aqueous fluoropolymer dispersion comprising an aqueous medium, fluoropolymer particles, and an amine oxide surfactant. Coagulated fluoropolymer resin is produced from the dispersion by adding an acidic reagent in sufficient amount to cause coagulation and separation of the coagulated fluoropolymer resin from the aqueous medium. Another particulate component such as particular polymer, filler, pigment, solid lubricant, etc., may be added to the dispersion and co-coagulated to form a mixture of coagulated fluoropolymer resin and particulate component.

Abstract: The present invention relates to a highly dielectric film formed by using (A) a fluorine-containing resin comprising vinylidene fluoride unit and tetrafluoroethylene unit in a total amount of not less than 95% by mole, and provides a film for a film capacitor which has high dielectric property and high withstanding voltage and can be made thin.

Abstract: A process comprising polymerizing at least one fluorinated monomer in an aqueous medium containing initiator and polymerization agent to form an aqueous dispersion of particles of fluoropolymer, the polymerization agent comprising: fluoropolyether acid or salt thereof having a number average molecular weight of at least about 800 g/mol; and fluorosurfactant having the formula: [R1—On-L-A?] Y+ wherein: R1 is a linear or branched partially or fully fluorinated aliphatic group which may contain ether linkages; n is 0 or 1; L is a linear or branched alkylene group which may be nonfluorinated, partially fluorinated or fully fluorinated and which may contain ether linkages; A? is an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion, and phosphonate; and Y+ is hydrogen, ammonium or alkali metal cation; with the proviso that the chain length of R1—On-L- is not greater than 6 atoms.

Abstract: A lithium battery binder includes polyvinylidenefluoride(PVDF) having an IR absorption peak ratio of I? in a range from 0.35 to 1.00, wherein I? is equal to I820-850/I860-880 where I820-850 is a peak height resulting from a CH2 rocking band in ?-phase PVDF and I860-880 is a peak height resulting from backbones in ?- and ?-phase PVDF. The lithium battery containing the cathode and/or the anode which incorporates the binder improves the charge/discharge characteristics and the lifespan characteristics of a lithium battery.

Abstract: There is provided a method of forming a thin film of vinylidene fluoride homopolymer having crystal form I which is applicable to various substrates in relatively easy way (coating conditions, application method, etc.), a process for preparing a vinylidene fluoride homopolymer having crystal form I efficiently at high purity, and novel vinylidene fluoride homopolymers which can give a thin film being excellent in ferroelectricity.

Abstract: In a process for the manufacture of fluoroelastomers, a water-soluble polymeric coagulant is employed that is an aqueous solution of polyethylene oxide homopolymer or copolymer having a viscosity average molecular weight of 500,000 or greater.

Abstract: Disclosed is a melt-flowable fluoropolymer comprising repeating units arising from (a) tetrafluoroethylene and (b) a monomer having at least one functional group and a polymerizable carbon-carbon double bond, wherein the sum of the weight percent of (a) and (b) comprises at least about 99 weight percent of all repeating units comprising the melt-flowable fluoropolymer.

Abstract: Disclosed is a melt processible semicrystalline fluoropolymer comprising: (a) about 0.001 to about 25 weight percent of repeating units arising from a hydrocarbon monomer having a functional group and a polymerizable carbon-carbon double bond, wherein said functional group is at least one selected from the group consisting of amine, amide, hydroxyl, phosphonate, sulfonate, nitrile, boronate and epoxidehydrocarbon monomer; and (b) the remaining weight percent of repeating units arising from tetrafluoroethylene. This melt processible semicrystalline fluoropolymer is impermeable to fuels and is useful as a lining for petroleum fuel tubing, as well as chemical resistance coating for, or adhesive between, perfluoropolymer and other polymers, metals and inorganics.

Abstract: Disclosed is a non-melt-flowable perfluoropolymer comprising repeating units arising from tetrafluoroethylene and a monomer having at least one functional group and a polymerizable carbon-carbon double bond.

Abstract: There is provided a method of forming a thin film of vinylidene fluoride homopolymer having crystal form I which is applicable to various substrates in relatively easy way (coating conditions, application method, etc.), a process for preparing a vinylidene fluoride homopolymer having crystal form I efficiently at high purity, and novel vinylidene fluoride homopolymers which can give a thin film being excellent in ferroelectricity.

Abstract: The present invention relates to a process for the removal of solvent from a polymer emulsion or suspension, by use of a decanter centrifuge (10). The decanter centrifuge (10) provides an efficient thickening method. The process is especially useful for emulsion or suspension polymer compositions having high levels of solvent (low polymer solids) that could benefit from a thickening or dewatering step prior to drying in a dryer (14).

Abstract: It is a polymer formed of fluorinated monomers and hydrocarbon monomers and another biocompatible polymer.

Abstract: To provide an ethylene/tetrafluoroethylene copolymer excellent in the thermal resistance, and a method for its production. The ethylene/tetrafluoroethylene copolymer is produced by polymerizing ethylene with tetrafluoroethylene in an organic solvent containing no chlorine atoms as a polymerization medium, in the presence of a chain transfer agent containing no chlorine atoms and a polymerization initiator containing no chlorine atoms, and further in the substantial absence of a chain transferable compound having a carbon-chlorine atomic bond in the reaction system.

Abstract: This invention provides a novel compound which can be properly used as a surfactant, a method of producing a fluoropolymer, surfactant and a fluoropolymer aqueous dispersions using the novel compound. This invention is a fluoroalkylcarboxylic acid derivative which is represented by the general formula (i): Rf1(OCH2CF2CF2)n1OCX1X2CF2(Rf2)n2COOM??(i) wherein Rf1 represents a straight or branched fluoroalkyl group containing 1 to 20 carbon atoms, which fluoroalkyl group may optionally contain 1 to 5 oxygen atoms in the principal chain thereof, Rf2 represents a straight or branched fluoroalkylene group containing 1 to 25 carbon atoms, said fluoroalkylene group may optionally contain 1 to 5 oxygen atoms in the principal chain thereof, n1 represents an integer of 0 to 3, n2 represents an integer of 0 or 1, X1 and X2 are the same or different and each represents hydrogen atom or fluorine atom, and M represents NH4 or a monovalent metal element.

Abstract: The invention provides a TFE polymer capable of providing stretched materials excellent in membrane homogeneity. The present invention is related to a tetrafluoroethylene polymer having stretchability and non-melt-processability and having a standard specific gravity of 2.140 to 2.165, wherein, with regard to the heat-of-fusion curve obtained by subjecting the tetrafluoroethylene polymer in the form of an unbaked polymer to be measured having no history of being heated to a temperature of 300° C. or higher to differential scanning calorimetry at a programming rate of 2° C./minute, the ratio between the amount of heat, S2 mJ/mg, absorbed within the temperature range of from the temperature T0° C., which is lower by 2.5° C. than the temperature Tp° C. corresponding to the minimum point on the curve (provided that 340?Tp?345), up to 350° C., and the amount of heat, S1 mJ/mg, absorbed within the temperature range of from 320° C. up to the above-mentioned T0° C., namely the ratio [S2/S1], is not lower than 0.90.

Abstract: Polymers of fluorinated monomers and acrylate and alkyl acrylates are disclosed which demonstrate improved performance as coatings for implantable devices. Such coatings may, for example, be used to release a bioactive agent from the medical device. One specific application lies in drug-eluting coatings for stents.

Abstract: A true tetrafluoroethylene (TFE) copolymer of the fine powder type is provided, wherein the copolymer contains polymerized comonomer units of at least one comonomer other than TFE in concentrations of at least or exceeding 1.0 weight percent, and which can exceed 5.0 weight percent, wherein the copolymer is expandable, that is, the copolymer may be expanded to produce strong, useful, expanded TFE copolymeric articles having a microstructure of nodes interconnected by fibrils. Articles made from the expandable copolymer may include tapes, membranes, films, fibers, and are suitable in a variety of end applications, including medical devices.