End of life plastics are scarcely recycled due to technical, health or structural constraints. To address this issue, a solvolysis route may be considered in order to recover monomers or other valuable molecules. Although good results are obtained after polymers sorting, this method remains sensitive to the composition of incoming flows, as well as the presence of contaminants. The Supercritical and Decontamination Processes Laboratory has developed an original depolymerization method in hydrothermal conditions (150 to 300°C and autogenous pressure) allowing to consider treatment of a mixture of end of life polymers (PET, PU, PC, PE, PVC). A parametric study will be carried out on a mixture of polymers of known composition by studying the influence of process parameters on the composition of the aqueous and organic phases, to define performance criteria such as conversion and depolymerization yields. Several end-of-life plastic wastes, alone or in a mixture, will be considered, to highlight a possible synergistic effect on the recovery of all or part of the recoverable monomers or products. Finally, an energy and mass balance will be implemented to study the complete life cycle of the process and to evaluate the relevance of the depolymerization process in hydrothermal conditions.