Résumé
Predicting barrier properties of multilayer materials is essential for designing effective food packaging. While resistance-based models are commonly used, their applicability to complex structures such as polymer-coated paper/cardboard remains underexplored. This study investigates the predictive ability of these models in multilayer systems composed of cellulosic substrates laminated with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Four model materials were designed to assess the influence of structural variations on oxygen and water vapor barriers. PHBV lamination significantly improved barrier properties (up to 100% improvement), primarily through the formation of an impregnated layer rather than a continuous film. Spatial heterogeneities observed within the samples were quantified and integrated into the modeling approaches. Different structural assumptions were also considered. None of the models succeeded in accurately predicting the barrier properties across all PHBV-laminated samples. This discrepancy suggests the influence of additional factors, such as interfacial adhesion, polymer crystallinity, or local defects, that must be further considered. This work proposes, for the first time, an experimental estimation of the impregnated layer’s permeability (from 10-15 to 10-13 mol.m.m-2.s-1.Pa-1 for oxygen permeability to 10-15 to 10-12 mol.m.m-2.s-1.Pa-1 for water vapor permeability). These findings underscore the critical role of the impregnated layer in mass transfers and the necessity to refine existing models.