Diethylene glycol, isophthalic acid, intrinsic viscosity, and acid number in PET granulate by NIRS

This Application Note describes the quantitative determination of diethylene glycol (DEG), isophthalic acid (IPA), intrinsic viscosity (IV), and acid number (TAN) of PET products on a NIRS DS2500 Analyzer. In contrast to the wet chemical determination – which takes several hours and requires trained chemists – the presented NIR method is extremely fast and can be performed by unskilled operators.