Résumé
INTRODUCTIONCoated papers and cardboards appear as excellent candidates for the conventional and polluting plastics’substitution in the packaging field. A polymer coating can compensate for the poor barrier properties ofpaper/cardboards towards gas and water vapor, and thus increase the range of application. Due to the paperintrinsic porosity, a part of the coated polymer unavoidably penetrates within the cellulosic substrate leadingto a complex multi-layered structure with at least three layers, having their own properties. Understandingthe relationship between this structure and the polymer-coated cardboards properties is necessary for thedevelopment of materials with tailored properties for packaging applications. While the impact of thecoating weight has already been studied [1], the impact of the overall complex structure, including theimpregnated layer, has never been investigated.In this context, the aim of this study is to formalize the relationship between the structure and the propertiesof polymer-coated cardboards.EXPERIMENTALFor that purpose, a range of coated cardboards displaying contrasted structures were produced bythermocompression, using a Design of Experiment, and further characterized. Untreated blotting paperswere considered to emphasize the phenomenon of polymer impregnation. PHBV, poly(3hydroxybutyrate-co-3-hydroxyvalerate), was used as polymer coating. First, the structure, i.e. thicknesses of the differentlayers, of the produced coated-cardboards was determined using an analytical model [2]. Then, the barrierand mechanical properties were characterized and the relationship between the structure and theseproperties was investigated.RESULTS AND DISCUSSIONIt has been highlighted that the properties of polymer-coated cardboards differed depending on their intrinsicstructure (Figure 1)CONCLUSIONSResults show the impact of the structures on the coated papers’ barrier and mechanical properties, andespecially the relative contribution of each layer. The barrier properties seem to be controlled by the freepolymer layer. However, it is worth noting that the process used to produce coated cardboards is alsoimpacting the properties of the materials.