Ethylene with tetrafluoroethylene ETFE

Copolymers of ethylene with tetrafluoroethylene (ETFE) and chlorotrifluoroethylene (ECTFE) are mechanically stronger than perfluoropolymers, with some reduction in their chemical resistance and continuous use temperature and an increase in the coefficient of friction. 

PVC, another widely used polymer for wire and cable insulation, crosslinks under irradiation in an inert atmosphere. When irradiated in air, scission predominates.To make cross-linking dominant, multifunctional monomers, such as trifunctional acrylates and methacrylates, must be added. Fluoropolymers, such as copol5miers of ethylene and tetrafluoroethylene (ETFE), or polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), are widely used in wire and cable insulations. They are relatively easy to process and have excellent chemical and thermal resistance, but tend to creep, crack, and possess low mechanical stress at temperatures near their melting points. Radiation has been found to improve their mechanical properties and crack resistance. Ethylene propylene rubber (EPR) has also been used for wire and cable insulation. When blended with thermoplastic polyefins, such as low density polyethylene (LDPE), its processibility improves significantly. The typical addition of LDPE is 10%. Ethylene propylene copolymers and terpolymers with high PE content can be cross-linked by irradiation. ... 

Copolymer of ethylene and tetrafluoroethylene (ETFE)is an alternating copolymer that can be cross-linked by irradiation.112 Further improvement is achieved with the use of prorads, such as TAC or TAIC in amounts up to 10%. 

T. Tran Duy, S.I. Sawada, S. Hasegawa, Y. Katsumura, Y. Maekawa, Poly(ethylene-co-tetrafluoroethylene)(ETFE)-based graft-type polymer electrolyte membranes with different ion exchange capacities relative humidity dependence for fuel cell applications, J. Membr. Sci. 447 (2013) 19-25. 

Examples of fluoroplastics include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), ethylene—chlorotrifluoroethylene (ECTFE), ethylene—tetrafluoroethylene (ETFE), poly(vinylidene fluoride) (PVDF), etc (see Fluorine compounds, organic). These polymers have outstanding electrical properties, such as low power loss and dielectric constant, coupled with very good flame resistance and low smoke emission during fire. Therefore, in spite of their relatively high price, they are used extensively in telecommunication wires, especially for production of plenum cables. Plenum areas provide a convenient, economical way to run electrical wires and cables and to interconnect them throughout nonresidential buildings (14). Development of special flame-retardant low smoke compounds, some based on PVC, have provided lower cost competition to the fluoroplastics for indoors application such as plenum cable, Riser Cables, etc. 

Extrusion-Applied Insulations. The polymers used in extrusion applications can be divided into two classes low-temperature applications and high-temperature applications. Polymers in the first category are poly(vinyl chloride), polyethylene, polypropylene, and their copolymers along with other elastomers. Polymers in the second category are mainly halocarbons such as Teflon polytetrafluoroethylene (which requires special extrusion or application conditions), fluoroethylene-propylene copolymer (FEP), perf luoroalkoxy-modified polytetrafluoroethylene (PFA), poly(ethylene-tetrafluoroethylene) (ETFE), poly(vinylidene fluoride) (PVF2) (borderline temperature of 135 °C), and poly(ethylene-chlorotrifluoroethylene). Extrusion conditions for wire and cable insulations have to be tailored to resin composition, conductor size, and need for cross-linking of the insulating layer. 

The significant contribution of Nafion or perfluorosulfonic membranes to the cost of the fuel cells stacks and the high alcohol crossover levels that affect the fuel efficiency, prompted the development of radiation grafted proton exchange membranes based on poly(ethylene-tetrafluoroethylene) (ETFE) [172-178], PVdF [175], andPTFE [179]. The peroxy radicals produced on the base polymer by y-ray, electron- or proton-beam, react with styrene to form a co-polymer that is then sulphonated. 

ETFE is a copolymer of ethylene and tetrafluoroethylene similar to ECTFE, but with a higher use temperature. It does not have the flame F F F CFg... 

ETFE is sold under the trade name of Tefzel by DuPont. It is a partially fluori-nated copolymer of ethylene and tetrafluoroethylene with a maximum service temperature of 300 F/149°C. Tefzel can be melt bonded to untreated aluminum, steel, and copper. It can also be melt bonded to itself. In order to adhesive bond Tefzel with polyester or epoxy compounds, the surface must be chemically etched or subjected to corona or flame treatments. 

Standard injection and extrusion equipment is used with the lower-viscosity polymers fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polyvinyli-denefluoride (PVDF), polyperfluoroalkoxyethylene (PFA), ethylene chlorotrifluoroethyl-ene (ECTFE), and others. This substitution, or copolymerization, where fluorine atoms have substitutes, results in property and processing changes. 

Ethylene-Tetrafluoroethylene Copolymer n A copolymer of ethylene and tetrafluoroethylene (DuPont Tefzel ), ETFE is readily processed by extrusion and injection molding. It has excellent resistance to heat, abrasion, chemicals, and impact, with good electrical properties. 

ETFE Poly(ethylene-co-tetrafluoroethylene) PVC-P Poly(vinyl chloride), plastisized with DOP... 

Commercial ETFE is an equimolar copolymer of ethylene and tetrafluoroethylene (1 1 ratio) and is isomeric with polyvinylidene fluoride. ETFE has a higher melting point than PVDF and a lower dissipation fac-torl l because of its special chain conformation. Crystalline density was 1.9 g/cm for a polymer containing 12% head-to-head defect, The unit cell of the crystal is expected to be orthorhombic or monoclinic with cell dimensions of a = 0.96 nm, b = 0.925 nm, c = 0.50 nm and 7= 96°. 

The most important interpolymers (e.g., copolymers, terpolymer, etc.) are those made with tetrafluoroethylene (ethylene tetrafluoroethylene polymer, ETFE) and chlorotrifluoroethylene (ethylene chlorot-rifluoroethylene polymer, ECTFE). These two polymers are generally produced by suspension or emulsion polymerization methods. There is resemblance between the polymerization technology of ETFE and ECTFE. Indeed, some of the same patent art could be studied to learn about the technology. This section and the next one present the polymerization of ETFE (Sec. 5.7) and ECTFE (Sec. 5.8). 

Copolymeis of ethylene [74-85-1] and tetiafluoioethylene [116-14-3] (ETFE) have been alaboiatory curiosity for more than 40 years. These polymers were studied in connection with a search for a melt-fabricable PTFE resin (1 5) interest in them fell with the discovery of TFE—HFP (FEP) copolymers (6). In the 1960s, however, it became evident that a melt-fabricable fluorocarbon resin was needed with higher strength and stiffness than those of PTFE resins. Earlier studies indicated that TFE—ethylene copolymers [11939-51 -6] might have the right combination of properties. Subsequent research efforts (7) led to the introduction of modified ethylene—tetrafluoroethylene polymer [25038-71-5] (Tefzel) by E. I. du Pont de Nemours Co., Inc, in 1970. 

Fig. 11. Effect of polyolefin primers on bond strength of ethyl cyanoacrylate to plastics. All assemblies tested in accordance with ASTM D 4501 (block shear method). ETFE = ethylene tetrafluoroethylene copolymer LDPE = low-density polyethylene PFA = polyper-fluoroalkoxycthylene PBT = polybutylene terephthalate, PMP = polymethylpentene PPS = polyphenylene sulfide PP = polypropylene PS = polystyrene PTFE = polytetrafluoroethylene PU = polyurethane. From ref. [73].

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