Abstract
Matrix‐assisted laser desorption/ionization mass spectrometry was used for the characterization of extracted and synthesized oligo(ethylene terephthalate)s. Generally, cyclic oligomers [GT]n could be found in technical yarns and tiles, whereas our synthesized model oligomers mainly consisted of linear chains H[GT]nG. In addition, some other distributions could be identified as H[GT]nOH and H[GGT]1[GT]n−1G linear oligomers and H[GGT]1[GT]n−1 cyclic oligomers, where G is an ethylene glycol unit, GG is a diethylene glycol unit, caused by impurities of ethylene glycol, and T is a terephthalic acid unit. NMR and IR investigations were carried out to verify these results.