Chemical resistance of EPM and EPDM rubbers

 
One of the most important features of properly formulated compounds based on Buna® EP is its exceptional resistance to aging and weathering i.e., to

• oxygen
• ozone
• water
• elevated temperatures
• UV radiation to a certain degree.

This is attributable to the saturated main chain of the polymer. Being a pure hydrocarbon rubber, Buna® EP is also inert to many chemicals.

The resistance of EP(D)M to solvents depends on its polarity. Their nonpolar and inert nature grades make the vulcanizates substantially resistant to many polar media or substances containing oxygen in the molecule, such as alcohols, ketones, esters and glycols, and also to water, typical coolants and brake fluids.

The polymers are also resistant to acids and bases. EP(D)M has generally poor resistance to oils based on hydrocarbons and to fuels. However, medium oil resistance can be obtained with the oil-extended grades of very high molecular weight. High termonomer contents improve the oil resistance by permitting higher crosslink densities.

 

Buna is a registered trademark in many countries of the world.