Schwefel- vs. Peroxid-Härtungssysteme: Was sich tatsächlich ändert

The cure system decides what kind of chemical bridge holds the polymer chains together. That bridge type drives heat ageing and compression set more than almost any other formulation variable.

Sulphur systems

Sulphur vulcanisation forms polysulphidic, disulphidic or monosulphidic bridges depending on the accelerator-to-sulphur ratio. Conventional systems (high sulphur, low accelerator) give long, flexible polysulphidic bridges: excellent fatigue and tear resistance, but poorer heat ageing. Efficient (EV) and semi-efficient (semi-EV) systems shift towards shorter bridges: better heat and reversion resistance, somewhat lower flex life.

Peroxide systems

Peroxide curing forms direct carbon-carbon bonds. The result is typically better heat resistance and lower compression set, and it avoids sulphur-related staining in some applications. The trade-offs are lower tear strength and flex fatigue, higher compound cost, and sensitivity to oxygen during curing in open steam or hot air.

How to specify

• •Dynamic parts operating below about 100 °C with flex fatigue as the main risk: conventional or semi-EV sulphur.
• •Static seals where compression set at elevated temperature dominates: peroxide or EV sulphur.
• •Parts in contact with copper or certain plating: check for sulphur staining before committing.

State the continuous service temperature and whether the part is static or dynamic. A supplier can then propose a cure system rather than guessing. ## Need the documents or today's price? Send us the grade, quantity and destination port — we return a quotation with COA and MSDS attached. Email manager@fipolymer.com or use the inquiry form on this site.