Determination of Additives in Polymer Pellets by Near-Infrared Spectroscopy

This application note demonstrates the capabilities of NIR spectroscopy for determining low concentrations of additives in finished polypropylene pellets. This is demonstrated by monitoring the UV stabilizer Tinuvin 770 and the antioxidant Irganox 225. The application of multiple linear regression (MLR) models minimizes interferences that originate from different coating thicknesses and interferences in the polymer pellets.