Metal–Organic Framework‐Gated Biocatalysis Enables Triggered Depolymerization of Melt‐Processed Polyesters

Abstract

ABSTRACT Controlling biocatalytic activity in melt‐processed polymers is a central challenge for triggered depolymerization, because enzymes deactivate at melt‐extrusion temperatures. Here, metal–organic framework‐gated biocatalysis, achieved by encapsulating enzymes within zeolitic imidazolate framework‐8 (ZIF‐8), preserves > 85% activity after 2 min at 180°C while regulating substrate access. Enzyme@ZIF‐8 biocomposite production scales to ∼50 kg day − 1 and is compounded by twin‐screw extrusion into poly(ε‐caprolactone) (PCL), poly(butylene adipate‐co‐terephthalate) (PBAT), and polylactide (PLA) at a tonne‐per‐day scale; pellets are compatible with standard thermoforming. The enzyme@ZIF/plastic composites retain mechanical performance comparable to the neat polymers during processing and use. At the end‐of‐life, chemical triggers dissolve the ZIF‐8 gate, releasing the enzyme, Zn 2 + and imidazolate to cooperatively accelerate depolymerization. Degradation increases 13.3–62.8‐fold for PCL and PLA in water and 1.7‐fold under industrial composting for PBAT and enables anaerobic PBAT digestion, whereas pristine polyesters show negligible conversion. This melt‐processable platform establishes gated, on‐demand depolymerization compatible with industrial polymer manufacturing.