Nanophase polymeric mixtures that show a phase transition through the application of pressure have developed by Mayes et al., being termed “baroplastics”. Block copolymers comprised of a low-Tg and a high- Tg component, such as poly（butyl acrylate）-b-polystyrene, can be processed at ambient temperature under pressure by a pressure-induced phase transition from ordered（solid）state to disordered（melt/solid）state. The low-temperature formability can not only reduce the required energy in processing, resulting in CO2 mitigation, but also suppress thermal degradation of the polymer chains with enhancing recyclability. The author developed degradable baroplastic block copolymers from renewables, which were expected further reduction of environmental impact of polymeric materials. The idea of low-temperature formability can be an effective solution toward the climate change and the end-of-life plastic issues. In this review, mechanism of the pressure-induced phase transition of block copolymers is outlined. Characterization and pressure-processability of degradable baroplastic block copolymers, such as poly（ε-caprolactone） derivative-b-polylactide and poly （trimethylene carbonate）-b-polylactide, are also introduced. The elastomeric properties of the block copolymers can be alternative to petroleum-based thermoplastic elastomers. In addition, potential applications of the block copolymers and the perspectives are also discussed.
