Method for determining the percentage of recycled polyethylene terephthalate

Abstract

The invention relates to a method for determining the percentage of recycled polyethylene terephthalate (hereinafter referred to as r-PET) in a material compared with the total amount of r-PET and non-recycled polyethylene terephthalate contained in the material M; This method includes the following steps: determining the molar ratio of IPA of each reference material from a series of reference materials, each reference material containing at least one IHT polymer and optionally IPA monomers and optionally TPA monomers, calculating the average value of the molar ratios of IPA of a series of reference materials, and preparing material M; Determine the molar ratio of IPA in material M by analyzing material M using at least one analytical method selected from the group including NMR, FT1Rf, Raman spectroscopy, NIR, GC, HPLC; determine the percentage of r-PET in material M RiPAí in RipA-Y / X* 100,