SEBS is a linear triblock copolymer with an end segment of polystyrene and an ethylene-butene copolymer obtained by hydrogenating polybutadiene as an intermediate elastomeric block. SEPS is a linear triblock copolymer with an ethylene-propylene copolymer obtained by hydrogenating poly isoprene as an intermediate elastomer block, which is a polystyrene-terminated segment.