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.