What's the difference between FPM and PKM?

What's the difference between FPM and PKM?

 

Both FKM and FPM are fluororubbers, but FKM is the European abbreviation, while FPM is the American abbreviation.

 

Fluororubbers can be divided into three basic types: fluorocarbon rubber, fluorosilicone rubber, and fluorinated phosphazene rubber.

Fluororubber is a special synthetic elastomer. Its main chain or side chains have carbon atoms bonded with highly electronegative fluorine atoms. Due to the high C-F bond energy (485 KJ/mol) and the covalent radius of the fluorine atom being 0.64 Å, equivalent to half the length of the C-C bond, the fluorine atoms can effectively shield the C-C main chain, ensuring its stability. This gives it superior properties unmatched by other rubbers, such as oil and chemical resistance, good physical and mechanical properties, weather resistance, electrical insulation, and radiation resistance. Among all synthetic rubbers, it has the best overall performance and is commonly known as the "King of Rubbers."