Abstract
Poly(ethylene terephthalate)(PET) was prepared by the continuous direct esterification of reagent grade terephthalic acid(TPA) or recycled TPA with ethylene glycol. We estimated the purity of the recycled TPA using thermogravimetry, infrared spectroscopy, and energy-dispersive X-ray spectroscopy. Purity of the recycled TPA was about 96~97%. We synthesized PET by controlling preparation conditions such as the type and amount of catalyst, ester interchange reaction time and teperature,and polycondensation time and temperature. Polycondensation temperature and time were controlled at 265~285$^{\circ}C$ and 14h, respectively. The number-average molecular weight (M$_{n}$) of PET obtained from reagent grade TPA and recycled TPA were about 50,000 and 30,000, respectively. A tough and stable film could be prepared by melt-casting of PET obtained using recycled TPA.A.
