Abstract: A method prepares polymeric material including polyester recycled by chemical recycling technology by glycolysis from waste, purification and subsequent repolymerization, to obtain a purified product with chemical-physical-mechanical features equal to virgin plastic material. The method includes providing raw material in the form of flakes for a glycolysis process obtained through a pre-treatment process of dirty post-consumer plastic of polyesters. Chemical depolymerization reacts by glycolysis to obtain a mixture defined “glycolysis product” based on the intermediate Bis-2-hydroxyethyl terephthalate and low-molecular-weight small oligomers. Purification of the glycolysis product uses ion exchange resins and adsorbents for removing contaminants and color and subsequent recovery of pigments separated from the plastic and subsequent evaporation and concentration reactions to obtain the pure BHET monomer, intermediate of PET production.