Compostable and Recyclable Baroplastic Triblock Copolymers Enable Low‐Energy Polymer Processing

ABSTRACT Baroplastic polymers enable low‐energy processing at low temperatures under mild pressure preserving polymer integrity and supporting end‐of‐life pathways that reduce the formation of persistent microplastic residues. Poly( L ‐lactide)‐ block ‐poly(ethylene glycol)‐ block ‐poly( L ‐lactide) (PLLA‐ b ‐PEG‐ b ‐PLLA) triblock copolymers demonstrate baroplasticity, enabling ambient temperature processing under moderate pressure. Here, we synthesized and characterized PLLA‐ b ‐PEG‐ b ‐PLLA with specific block lengths, showing rapid degradation within 2 months under industrial composting conditions and effective chemical and physical recyclability. Low‐temperature baroplastic processing preserves the activity of encapsulated heat‐sensitive proteins, expanding its application potential. These findings suggest that PLLA‐ b ‐PEG‐ b ‐PLLA combines sustainable processing, compostability, and recyclability, offering a promising platform for environmentally friendly polymer technologies in packaging, agriculture, and beyond.