Exafs study of a germanium catalyst in pet polymer

Abstract

Despite of its usefulness in gaining valuable structural information on a variety of catalysts, XAFS has not been previously used to study the catalysts remaining in polymers. In the production of PET (polyethylene terephthalate) bottles, germanium oxide is used as a polymerization catalyst to improve transparency, and the catalyst remains in those products at very low concentration levels of a few tens of ppm. In the present study, the structure of germanium remaining in a PET bottle was determined by use of the EXAFS method. It was found that germanium in the PET, forming a crystalline germanium oxide structure, has a somewhat less ordered structure than germanium oxide. © 1993 The Japan Society of Applied Physics.