Structure characterization of oligomers in recycled polyester fabric

The mass fraction of oligomers in polyester fiber is analyzed by ultrasonic extraction. The solubility property of the main component of gray powder which is separated during the calendering process of recycled polyester trademark fabrics is investigated. The chemical structure is characterized by infrared spectrum( FT-IR),gel permeation chromatography( GPC),differential scanning calorimetry( DSC) and nuclear magnetic resonance spectroscopy(1H-NMR). The results show that compared with the common polyester fibers,the recycled polyester fibers have relatively-high mass fraction of oligomers;and the gray powder has good solubility in chloroform,and the main component of gray powder is poly( ethylene terephthalate) three-membered cyclic oligomers determined according to the results of the FTIR and1H-NMR.