Investigation of conventional analytical methods for determining conversion of polyethylene terephthalate waste degradation via aminolysis process

There is a growing interest in the depolymerization of polyethylene terephthalate (PET) waste for both environmental and economic reasons by chemical methods. In this work, PET waste was depolymerized through aminolysis using excess amount of monoethanolamine. Bis (2-hydroxy ethylene) terephthalamide (BHETA) was obtained as the main product. For the first time, the reaction conversion was calculated, by FTIR, DSC, TGA, and CHN methods, and compared with that of measured by conventional gravimetric method. As a result, TGA and DSC are the suitable methods for calculating the reaction conversion. The gravimetric method does not measure reaction conversion, but correctly measure the yield of reaction.