Sbs (polystyrene-polybutadiene) is a block co-polymer, it is considered a thermoplastic elastomer and is produced by living anionic polymerization a. briefly explain the underlined terms b. list the two molecular characteristics that are essential for elastomers 4 c. 141 explain how block polymers are produced, show initiation and propagation steps for the formation of styrene block only. explain how the block structure of sbs results in a polymer exhibiting both elastomeric mechanical properties and thermoplastic processability.