Reversion Cure for EPDM

[Julia Mahir]

Generally EPDM is known for its marching cure properties.

Is there any possible sulphur cure mixture that we can use for reversion cure for EPDM? or possible for rubber blend?

Thanks.

 

[GrahamBennett]

Julia, there is a limit to the amount of marching that a sulfur-cured EPDM will undergo. This is controlled by the amount of diene modification that is pendent to the main EP molecular chain. (The EP molecular chain is fully saturated, i.e. it contains only C-C bonds, which cannot be broken by a sulfur cure system.) Once all the double bonds in the pendent diene molecules have been used up, that's it, no more cure can take place.

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[Julia Mahir]

Thanks, Graham.

I try to understand - more dience content, more double bonds need to be used up, longer cure? Does that mean I can try use lower diene content of EPDM?

Will it give much effect?

 

[btrueblood]

I thought "fast cure EPDM" used more, not less, diene?

 

[Julia Mahir]

@btrueblood

I must have missunderstood what Mr Graham said.