FEPM - Tetrafluoroethylene Propylene

Properties

Tetrafluoroethylene propylene (FEPM, TFE/P), also known as Aflas®,1, is a partially fluorinated polymer that is composed of both propylene and tetrafluoroethylene monomers which can be crosslinked using a variety of curatives such as peroxides.

 

This type of a copolymer offers a combination of high temperature and chemical resistance. Similar to other fluoroelastomers, it has excellent resistance to a broad range of chemicals including acids, bases, ozone, oxidizers, corrosion inhibitors, (hydraulic) oils, phosphate esters, alcohols and hot water/steam. However, FEPM is not compatible with aromatic and chlorinated hydrocarbons, and some fairly common organic solvents such as MEK, toluene, acetic acid, and acetone. Some other major disadvantages include high compression set, high glass transition temperature, low cold temperature performance, and poor extrusion resistance, especially at high temperatures, which makes FEPM difficult to process. Furthermore, it is rather expensive and, thus, only used when the components have to withstand harsh environments.

 

COMMERCIAL FEPM Elastomers

Important manufacturers and suppliers of tetrafluoroethylene propylene elastomers (FEPM, TFE/P) are Asahi Glass Company (AGC) and DuPont.

 

Applications

Tetrafluoroethylene propylene is widely used in the chemical, automotive, aerospace, and oil industry. It provides some of the best all-around chemical resistance, very low gas permeability and is mainly used for the manufacture of seals and wire and cable insulation operating in harsh environments.

The typical service temperature of FEPM is between -55C (-65°F) and +230°C (+445°F). However, at high service temperatures FEPM is rather weak, so that the design must prevent any high loads.

Notes
  1. Aflas® is a registered trade mark of Asahi Glass Co.

Main Properties

Temp. Range, °C -55 / 230
Compression Set Fair
Strength Properties Fair/Good
Low Temp. Perf. Poor
Abrasion Resist. Excellent
Gas Permeability Low
Weather Resist. Excellent
Water/Steam Resist. Excellent
Ozone Resistance Excellent
Oil Resistance

Fair (aliph.)
Poor (arom.)

Chemical Resist. Good
Flame Resistance Excellent
Heat Resistance Excellent