Tri- and star-block copolymers were investigated with respect to their "baroplastic" properties. A series of well-defined baroplastic materials containing immiscible low and high T, segments were synthesized by atom transfer radical polymerization. The polymers with different topologies can be processed by applying pressure at room temperature. "Processability and multiple recyclability were examined. The potential of baroplastic materials as processing aids in the processing of polystyrene at ambient temperature was also evaluated.