Polyisoprenes, natural (from trees) and synthetic, are noted for outstanding resilience, resistance to tear and abrasion, excellent elasticity, and flex fatigue resistance.
They also have excellent tensile strength characteristics and are operable in low temperature -65ºF (-54ºC) environments. They are not recommended for high heat, ozone, sunlight, petroleum or hydrocarbon environments.
The two isoprenes differ slightly; the purity of synthetic polyisoprene provides more consistent dynamic properties with better weather resistance. Synthetic polyisoprene’s lack of “tree” organics also gives a relatively odorless rubber.
Natural rubber, when compared to synthetic, provides slightly better properties in tensile strength, tear resistance, compression set, and flex fatigue resistance.