Resonance-Structured Energy Delivery for Polymer Depolymerisation: A Sympathetic Harmonic Resonance Framework (SHRF) Interpretation

abstract Plastic depolymerisation is conventionally treated as a bulk thermal or chemical activation problem, in which sufficient energy is supplied to overcome average bond dissociation barriers. This approach frequently results in inefficient energy use, broad product distributions, and undesirable crosslinking or char formation. Here we propose an alternative interpretation based on the Sympathetic Harmonic Resonance Framework (SHRF), in which depolymerisation is viewed as a coherence-to-dissipation transition driven by structured oscillatory fields. Rather than targeting individual bond frequencies, energy delivery is shaped spatiotemporally to form transient dissipation nodes where local scission thresholds are exceeded prior to global thermal equilibration. We examine acoustic, electromagnetic, and oscillatory shear excitation modalities, and show how pulsed or multi-frequency excitation can enhance depolymerisation efficiency when coupled to catalytic interfaces. A dimensionless coherence efficiency metric is proposed to compare structured excitation against conventional continuous heating. This framework provides a physically conservative yet experimentally testable route toward lower-energy, higher-selectivity plastic recycling technologies. polymer depolymerisation, resonance, mechanochemistry, acoustic cavitation, microwave heating, SHRF, energy localisation, plastic recycling, catalysis, non-equilibrium systems