Abstract:
Various aspects of the present disclosure are directed toward apparatuses, systems, and methods that include a cord that is flexible and elongated defining a length. The cord may include a core having a porous surface and a porosity-reducing element on at least a portion of the core.
Abstract:
The invention pertains to a perfluoroelastomer composition comprising: - at least one perfluoroelastomer comprising iodine and/or bromine atoms [perfluoroelastomer (A)]; - from 0.5 to 5 weight parts, per 100 parts by weight of said perfluoroelastomer (A), of at least one bis-olefin [bis-olefin (OF)] having general formula (1) wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 , equal or different from each other, are H, a halogen, or a C 1 -C 5 optionally halogenated group, possibly comprising one or more oxygen group; Z is a linear or branched C 1 -C 18 optionally halogenated alkylene or cycloalkylene radical, optionally containing oxygen atoms, or a (per)fluoropolyoxyalkylene radical; - from 0.1 to 3 weight parts, per 100 parts by weight of said perfluoroelastomer (A), of at least one organic peroxide; - from 0.1 to 3 weight parts, per 100 parts by weight of said perfluoroelastomer (A), of at least one organic base [base (B)] selected from the group consisting of: (i) non-aromatic primary amines or amides complying with general formula (B1m) or (Bid): R bm -[C(0)] t -NH 2 (B1m) H 2 N-[C(O) ]t' -R dm -[C(O) ]t" -NH 2 (Bid) wherein: - each of t, t' and t", equal to or different from each other and at each occurrence is zero or 1; - Rbm is a monovalent hydrocarbon non-aromatic group having 12 to 30 carbon atoms; - Rdm is a divalent hydrocarbon non-aromatic group having 6 to 30 carbon atoms; and (ii) cycloaliphatic secondary or tertiary amines complying with general formula (II) (B2m) or (B2d) wherein: - Cy represents a divalent aliphatic group comprising at least 4 carbon atoms, optionally comprising one or more than one ethylenically unsaturated double bond, and optionally comprising one or more catenary nitrogen atoms, forming a cycle with the nitrogen atom which is connected thereto; - Cy' represent a trivalent aliphatic group comprising at least 5 carbon atoms, optionally comprising one or more than one ethylenically unsaturated double bond, and optionally comprising one or more catenary nitrogen atoms, forming a cycle with the nitrogen atom which is connected thereto.
Abstract:
The invention pertains to a thermoplastic vulcanizate fluorine-containing composition [vulcanizate (C)], comprising a continuous thermoplastic fluoropolymer phase and a dispersed vulcanized fluoroelastomer phase, said composition comprising: - at least one thermoplastic fluoropolymer [polymer (F)], said polymer (F) comprising (j) from 40 to 60% by moles of recurring units derived from ethylene (E); (jj) from 60 to 40% by moles of recurring units derived from at least one of chlorotrifluoroethylene (CTFE) and tetrafluoroethylene (TFE); and (jjj) from 0.5 to 10% by moles of recurring units derived from of at least one (per)fluoroalkylvinylether of formula CX2=CX-OR f , wherein each of X, equal to or different from each other, is independently H or F (preferably F); and R f is a C 1 -C 12 (per)fluoroalkyl group or a C 1 -C 12 (per)fluoro-oxy-alkyl group comprising one or more than one catenary oxygen atoms [monomer (V)], with % by moles being referred to the total moles of recurring units of the polymer (F); and - at least one (per)fluoroelastomer [elastomer (A)].
Abstract:
A leaflet for a prosthetic valve formed of at least one layer that includes a composite material containing at least one expanded fluoropolymer membrane having serpentine fibrils and an elastomer is provided. The fluoropolymer may be polytetrafluoroethylene. In at least one embodiment, the elastic properties are present in an axial direction the leaflet. The leaflets may be single layered or multi-layered. The leaflets may be coupled to a support structure and movable between open and closed configurations relative to the support structure to form a heart valve. The elasticity within the leaflets permits, among other things, the leaflets to bend with a reduced occurrence of wrinkles as the valve opens and closes. The elastic properties of the leaflet also, among other things, improve bending properties and reduce closure stresses, thereby extending the life of the leaflet.
Abstract:
Fluoroelastomer compositions comprising fluoroelastomers having copolymerized units of a nitrile-containing cure site monomer are cured with certain phenol hydrazine complex curatives.
Abstract:
The present invention pertains to a pipe comprising at least one layer at least comprising, preferably consisting essentially of (or being made of), a tetrafluoroethylene (TFE) copolymer comprising from 0.8% to 2.5% by weight of recurring units derived from at least one perfluorinated alkyl vinyl ether having formula (I) here below: CF 2 =CF-O-R f (I) wherein R f is a linear or branched C 3 -C 5 perfluorinated alkyl group or a linear or branched C 3 -C 12 perfluorinated oxyalkyl group comprising one or more ether oxygen atoms, said TFE copolymer having a melt flow index comprised between 0.5 and 6.0 g/10 min, as measured according to ASTM D1238 at 372°C under a load of 5 Kg [polymer (F)]. The invention also pertains to use of said pipe in heat exchangers and in downhole operations including drilling operations.
Abstract:
A liquid composition comprising at least one aprotic organic solvent and at least one fluorinated ion exchange polymer which consists of recurring units derived from a chlorofluoroolefin of formula CF 2 =CCIY, wherein Y is F or CI, and from at least one fluorinated functional monomer selected among those of formula CF 2 =CF-O-(CF 2 CF(CF 3 )O) m -(CF 2 ) n SO 2 X, wherein m is an integer equal to 0 or 1, n is an integer from 0 to 10 and X is chosen among halogens (CI, F, Br, I), -O - M + , wherein M + is a cation selected among H + , NH 4 + , K + , Li + , Na + , or mixtures thereof is disclosed. The liquid composition is suitable for the preparation of ion exchange membranes, in particular composite membranes, for use in fuel cell applications.
Abstract:
A composition comprising a mixture of fluoropolyether acids or salts having a number average value of about 800 to about 2500 g/mol. The amount of fluoropolyether acids or salt in the mixture having a molecular weight of not more than 500 g/mol is not more than 50 ppm by weight of the total amount of fluoropolyether acids or salts in the mixture. The amount of fluoropolyether acids or salts in the mixture having a molecular weight of 2500 g/mol or greater is not more than 40% by weight of the total amount of fluoropolyether acids or salts in the mixture. Preferably the fluoropolyether acids or salts comprise an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion and phosphonate. Also disclosed is an aqueous dispersion polymerization process for fluoropolymer manufacture employing polymerization agent comprising the specified mixture of fluoropolyether acids or salts.