This study evaluates the low-velocity impact response of aerospace-grade epoxy laminates (M18/1) interleaved with four distinct thermoplastic films (PEI, PES, PSU, and PC). Impact performance was correlated with quasi-static fracture toughness to assess the transferability of intrinsic polymer properties to dynamic loading. The results reveal a fundamental trade-off governed by chemical compatibility. Chemically compatible interphases (PEI and PES) successfully bridged the stiffness mismatch, increasing the damage initiation threshold by up to 23%, although total energy absorption plateaued due to matrix saturation. Conversely, the incompatible polycarbonate (PC) system exhibited a mechanism shift: despite high intrinsic ductility, low Mode I adhesion (GIc) caused immediate decoupling, triggering a pseudoplastic sliding mode that increased energy absorption by 10% at the cost of structural integrity. Polysulfone (PSU) revealed an inefficient compromise, suffering from premature adhesive failure without providing significant energy dissipation. These findings challenge established propagation-based models and identify Mode I initiation toughness as the critical gatekeeper for structural toughening in hybrid laminates.     «

This study evaluates the low-velocity impact response of aerospace-grade epoxy laminates (M18/1) interleaved with four distinct thermoplastic films (PEI, PES, PSU, and PC). Impact performance was correlated with quasi-static fracture toughness to assess the transferability of intrinsic polymer properties to dynamic loading. The results reveal a fundamental trade-off governed by chemical compatibility. Chemically compatible interphases (PEI and PES) successfully bridged the stiffness mismatch, in...     »