ETFE: Ethylene-tetrafluoroethylene

General Properties

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ETFE

Ethylene-tetrafluoroethylene

Ethylene tetrafluoroethylene (ETFE) is a semi-crystalline PTFE derivate, but features a lower temperature stability.

Structural Formula

Properties

Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.Glass Transition Temperature	75 to 85°C
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Temperature	225 to 275°C
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Enthalpy	46 J/g
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature	385 to 400°C
Young's Modulus	1100 MPa
Coefficient of Linear Thermal Expansion (CLTE/CTE) The coefficient of linear thermal expansion (CLTE) describes the length change of a material as a function of the temperature.Coefficient of Linear Thermal Expansion	40 *10^-6/K
Specific Heat Capacity	0.9 J/(g*K)
Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.Thermal Conductivity	0.23 W/(m*K)
DensityThe mass density is defined as the ratio between mass and volume. Density	1.7 g/cm³
Morphology	Semi-crystalline polymer
General properties	High toughness. High abrasion and dielectric resistance. Weather-resistant. High light and UV transmission (films). Higher resistance to beta and gamma radiation than PTFE
Processing	Injection molding, extrusion
Applications	Electronics sector (coil formers, base, switches, cable insulation…). Architecture (films). Material for valves, fittings, hoses. Aerospace. Nuclear Industry

NETZSCH Measurement

Instrument	DSC 204 `F1` `Phoenix^®`
Sample Mass	11.12 mg
IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase	10 min
Heating/Colling Rates	10 K/min
Crucible	Al, pierced lid
Atmosphere	N₂ (40 ml/min)

Evaluation

The 1^st heating (blue) shows a RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation peak that obscures the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition and a melting peak with a shoulder (peak temperature 258°C). The Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition with a midpoint temperature of 80°C is clearer in the 2^nd heating (red). The shoulder is gone from the melting transition which peaks at 259°C.