<p>The present work investigates the impact of successive thermomechanical recycling cycles on the shear and elongation rheological properties of flexible multilayer barrier films. The main objective is to use these rheological properties as indicators to probe recycling-induced structural modifications in model multilayer films composed of polypropylene (88 wt%), ethylene–vinyl alcohol (7 wt%) as the barrier layer, and maleic anhydride-grafted polypropylene (5 wt%) as the compatibilizing tie layer. On one hand, small-amplitude oscillatory shear (SAOS) measurements reveal variations in the viscoelastic properties of the multilayer film: complex viscosity decreases up to the second recycling cycle due to PP β-scission, increases in the third recycling cycle likely due to chain crosslinking and copolymer formation between EVOH and PP-g-MA. Beyond the third cycle, a further decrease in viscosity was recorded, which may be associated with weakened interfacial adhesion and the coalescence of EVOH domains within the PP matrix. These results were further supported by morphological observations using SEM and by FTIR spectroscopy analyses. On the other hand, uniaxial extensional rheology, revealed a strong sensitivity to the competing effects of PP degradation and EVOH crosslinking. Despite the strain-softening behavior of the individual constituents, a pronounced strain-hardening response develops after multiple reprocessing cycles. Interestingly, modelling of the interfacial stress contribution highlights its decrease with increasing recycling cycles. The interfacial stress is initially higher in the multilayer film due to interface/interphase continuity and chain entanglements but progressively reduced by thermomechanical processing, owing to interfacial discontinuity and nodular morphology development in the recycled multilayers systems.</p> Graphical Abstract <p></p>