NATURAL RUBBER ( NR )
Natural rubber (tapped from the cultivated rubber tree) exhibits high tensile strength, abrasion resistance, resilience, tear strength and low hysteresis.
The chemically similar polyisoprene has lower strength properties than the natural form but better low-temperature properties. Both rubbers are susceptible to degradation by weathering characteristics, and both show poor resistance to mineral and petroleum-based oils and fuels.
Typical long-term operating range is from -50°C to 70°C.
Main applications for natural rubber materials, apart from tyres, are for vibration mounts, springs and bearings.