by Luis Rodríguez-Guadarrama and Roberto Fernández Pérez, Dynasol Group
Products produced by anionic polymerization of nonpolar monomers, such as polybutadienes (BR), polyisoprenes (IR), solution styrene butadiene rubbers (SSBR) and styrenic block copolymers (SBC), already dominate important positions in industries. Examples include thermoplastic elastomers, adhesives, impact modifiers, lubricant modifiers, vulcanized compounds, asphalt modification and others. SBCs combine the properties of a thermoplastic resin, polystyrene and those of an elastomer, polybutadiene, polyisoprene or poly(ethylene-co-butylene). SBCs derive their useful properties from their ability to form distinct styrene (hard phase) and diene (rubber phase) domains.