NR, SBR, BR, EPDM, NBR: elección del polímero base

Selecting the polymer is the first decision and the hardest to reverse. The reliable way to choose is to start from the failure mode you need to avoid, then work backwards.

Quick selection map

• •NR (natural rubber) — excellent tear strength, resilience and low heat build-up. Poor in oil, ozone and high heat. Typical uses: truck tyre carcasses, engine mounts, conveyor belt covers.
• •SBR — the volume workhorse. Good abrasion resistance and processability at a stable price. Weaker tear strength and heat resistance than NR. Typical uses: passenger tyre treads, general moulded goods.
• •BR (polybutadiene) — very high resilience and outstanding low-temperature flexibility, excellent abrasion resistance. Usually blended with NR or SBR rather than used alone, because it processes poorly on its own.
• •EPDM — outstanding ozone, weather and heat resistance, good electrical insulation. Poor in oil and fuel. Typical uses: automotive weatherstrip, hose covers, roofing membrane.
• •NBR — the standard choice where oil and fuel resistance is required; resistance improves as acrylonitrile content rises, but low-temperature flexibility gets worse at the same time.

The trade-off buyers miss

Increasing a performance property usually costs another one. Higher acrylonitrile NBR resists oil better but stiffens at low temperature. Higher filler loading cuts cost but raises heat build-up in dynamic parts. Always state the service temperature range, the media contact and the expected life — a polymer chosen on price alone is the most common cause of early field failure. ## 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.