Glycolization of polyethylene terephtalate (Pet) from waste bottle by diethylene glycol (Deg)

Abstract

Recycled PET (from soft drink bottle) reacted with diethylene glycol (DEG) to produce oligomers with various molecular weights depending on the DEG/PET ratios. The structure of the oligomers was characterized by LC-MS, and the molecular weight was also identified by titration method. The obtained oligomer from DEG/PET:1/1 is a mixture of trimers, pentamers or heptamers with EG/DEG end groups. The reaction time decreases as the catalyst concentration increases. The oligomer could be further modified to be used as polyester polyol for the valuable polyurethane industry/unsaturated polyester.