Ethylene propylene diene terpolymer

Ethylene propylene diene terpolymer (CAS 25038-36-2), commonly known as EPDM, is a synthetic elastomer produced from ethylene, propylene, and a diene monomer. It is used across rubber compounding, sealing, and insulation applications. This material is preferred where long-term resistance to heat, ozone, and weathering is a commercial requirement. In automotive manufacturing, EPDM is the primary material for door seals, window gaskets, and under-hood hoses.

Dimensional stability under thermal cycling is critical for these automotive components. Roofing membrane producers rely on EPDM sheeting as a durable waterproofing layer for flat and low-slope commercial roofing systems. Wire and cable manufacturers use it as an insulating jacket material in medium-voltage applications requiring flexibility at low temperatures. In polymer blending, EPDM functions as an impact modifier and rheology modifier.

When used in polypropylene compounds, it improves toughness in injection-molded automotive and appliance components. EPDM is supplied as bales, granules, or pellets depending on Mooney viscosity grade and diene content. Grades are differentiated by ethylene content, ENB (5-ethylidene-2-norbornene) or DCPD diene type, and oil-extended versus non-extended formulations. Both peroxide-curable and sulfur-curable grades are available.

These various formulations allow manufacturers to match specific compounding requirements for diverse industrial needs. The material remains a versatile choice for high-performance rubber applications globally.