Full definition
Any elastomer produced by chemical polymerization of petroleum-derived monomers, as opposed to natural rubber harvested from Hevea brasiliensis trees. Global synthetic rubber production: ~15 million tonnes/year (roughly equal to NR). Major types and their key attributes: SBR (general purpose, lowest cost), BR/polybutadiene (highest resilience, tire treads), NBR/nitrile (oil resistance, seals), EPDM (weather/ozone/steam resistance), CR/neoprene (balanced properties, flame resistance), IIR/butyl (gas impermeability, damping), silicone VMQ (extreme temperature range), FKM/fluorocarbon (chemical/heat resistance), and PU/polyurethane (highest abrasion/mechanical strength). Each synthetic rubber was developed to address specific limitations of NR: oil resistance (NBR), ozone resistance (EPDM, CR), heat resistance (FKM, silicone), gas barrier (IIR), etc. Raw material: petroleum-derived monomers (butadiene, styrene, acrylonitrile, ethylene, propylene, chloroprene, etc.). Polymerization: emulsion (water-based), solution (solvent-based), or gas-phase processes. Per ASTM D1418 for nomenclature and classification of rubber types.