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

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.