What’s the difference between sulfur curing and peroxide curing?
Charles Goodyear’s original rubber vulcanization process relied upon sulfur to cross-link the rubber polymer. With a few improvements in the control of the reaction, this same chemical process is still in use today. Most nitrile polymers in production today are sulfur-cured, as this is still the most predictable and cost-effective method of rubber processing. Peroxide-curing of nitrile rubber polymers provides improved compression set resistance and high temperature stability, but with reduced elongation and flex life. Unfortunately, the term “peroxide cured” has become a buzzword for “low compression set.” While this is generally true for nitrile and EPDM materials, it is not for some other polymers (notably fluorocarbon.) In general, it’s far more reliable to define a specification around a given performance level than a certain rubber compounding practice or method of manufacture.
