The subject of this study is the synthesis of glycolysates from recycled poly (ethylene terephthalate) (PET) by depolymerization using diethylene glycol (DEG) in the presence of catalyst FASCAT 4100. The resulting glycolysate was then treated with maleic anhydride and finally with 2-octanol to obtain a 2-EtHex/MA/DEG/PET/EG/MA/2-EtHex plasticizer. The characterization of the obtained plasticizer was performed by infrared spectroscopy with Fourier transform (FTIR) and NMR spectroscopy. The obtained plasticizers were mixed into bitumen with 10 wt. % and tests of mechanical properties of obtained products were performed.