FEP: Tetrafluoroethylene/hexafluoropropylene copolymer

General Properties

Short Name:

Name: 

FEP

Tetrafluoroethylene/hexafluoropropylene copolymer


Fluorinated ethylene propylene (FEP) is similar in its composition to PTFE or PFA; it is, however, softer and can be processed in conventional injection molding.

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-
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 Temperature253 to 282°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-
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature510 to 600°C
Young's Modulus350 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 Expansion80 *10-6/K
Specific Heat Capacity1.12 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 Conductivity0.25 W/(m*K)
DensityThe mass density is defined as the ratio between mass and volume. Density2.12 to 2.17 g/cm³
MorphologySemi-crystalline polymer
General propertiesGood chemical resistance. High impact strength. Smooth surface
ProcessingInjection molding, extrusion
ApplicationsHeating cables, heating tapes. Electronics (e.g., wires, cables on the communication sector). Chemical industry (lining for valves, tubes, container). Solar cells (layer films)

NETZSCH Measurement

InstrumentDSC 204 F1 Phoenix®
Sample Mass11.13 mg
IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase5 min
Heating/Colling Rates10 K/min
CrucibleAl, pierced lid
AtmosphereN2 (50 ml/min)

Evaluation

The present FEP sample shows an endothermal melting eff ect at 266°C (peak temperature, 2nd heating, red) in the temperature range between 0°C and 310°C with a melting enthalpy of 24 J/g. The shift of the peak temperature of more than 2 K to lower values in the 2nd heating (266°C compared to 268°C in the 1st heating, blue) can be explained by a better contact between the sample and crucible bottom after the first melting. The melting peak in the 1st heating (blue) is a bit slimmer compared to the 2nd heating; this indicates a narrower distribution of crystallite size.