Promotional effect of copper(II) chloride on the thermal degradation of poly(ethylene terephthalate)

The thermal degradation of fiber-grade powders, bottle-grade pellets, and waste bottle flakes of poly(ethylene terephthalate) (PET) samples were studied by a batch pyrolysis operation at atmospheric pressure. The degradation temperature of this work was in the range 350-500 °C. Copper(II) chloride was found to be an effective additive for enhancing the degradation ability of these three kinds of PET samples. The percentage weight loss of these samples degraded with such an additive was in the order, fiber-grade powders>waste bottle flakes≥bottle-grade pellets. The methods of mixing PET sample and additive affect the extent of degradation of PET. For most cases, the impregnation method showed higher extent of degradation than physical mixing. The effect of other factors, degradation temperature and degradation time, on the extent of degradation of PET when copper(II) chloride was used as an additive was also investigated. Pyrolysis GC-MS was carried out at 445 °C for 6 s to analyze the gaseous product distribution. The results showed that the gaseous products distribution of PET samples degraded with or without copper(II) chloride were little different. But the relative concentration of each gaseous product was changed.