PET SYNTHESIS IN THE PRESENCE OF LANTHANIDE CATALYSTS

Syntheses of poly(ethylene terephthalate), PET, by transesterification of dimethyl terephthalate with ethylene glycol in the presence of wel l-known catalysts and various lanthanide compounds were performed. Lan thanide catalysts appeared to be much more efficient in the first stag e of the process (transesterification in the presence of an excess of ethylene glycol), and less active in polycondensation. PET produced wi th lanthanides was found to possess enhanced thermal and hydrolytic st ability as compared to PET synthesized with well-known catalysts and c ommercial PET. (C) 1995 John Wiley & Sons, Inc.