Recycling of waste PET-bottles using dimethyl sulfoxide and hydrotalcite catalyst



The degradation of PET bottles has been successfully achieved using hydrotalcite as catalyst and dimethyl sulfoxide (DMSO) as solvent. The reaction was carried out at boiling point of DMSO (190°C) and degradation was complete in 10 min. The oligomer (tetramer) obtained was treated with NaOH at room temperature in methanol to get dimethyl terephthalate (DMT) and ethylene glycol (EG). Thus, it is a safe and cleaner process. Oligomer was characterized by MS,13C-NMR, X-ray diffractometric, and thermogravimetric analysis. DMT and EG were characterized by GC-MS. DMT was also characterized by FT-IR. GC-MS analysis shows that the purity of DMT was 99%. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012