FEP
Fluorinated Ethylene Propylene
Glass Transition (Tg)
~-90 °C
Melting Point (Tm)
260 °C
Density
2.15 g/cm³
CAS Number
25067-11-2
Recycling Code
♺ 7
Category
High-Performance
Repeat Unit
–[CF₂–CF₂]ₓ–[CF₂–CF(CF₃)]ᵧ–
The repeating unit is the smallest structural fragment whose repetition builds the whole chain. Subscripts show the relative share of each unit in copolymers.
Key Properties
Retains most PTFE properties but is genuinely melt-processable; transparent in thin film; lower service temperature than PTFE.
Applications
Wire insulation, chemical tubing, solar-panel front sheets, release film.