Method for measuring contents of different types of PET (Polyethylene Terephthalate)

The invention relates to a method for determining the content of different types of hydroxyl-terminated ethylene oxide-tetrahydrofuran copolyether (PET) in a nitrate plasticized polyether (NEPE) adhesive system. According to the determination method, PET is separated from a mixed sample containing P-type PET and T-type PET by using a gel permeation chromatograph to obtain a GPC chromatogram of the mixed PET, the chromatogram of the P-type PET sample and the chromatogram of the T-type PET sample are measured by using the gel permeation chromatograph, and the contents of P-type PET and T-type PET in the mixed chromatogram are obtained through digital fitting. The invention further provides a test parameter and data processing method. The determination method has important significance for analyzing and testing the proportion of the two-functionality PET and the three-functionality PET in the adhesive, adjusting and controlling the quality of the adhesive and researching the influence of different PET on the mec