This method is for the determination of Irganox 3114 and chemically identical antioxidants in polypropylene where the additive package is known. The method utilizes a characteristic carbonyl band associated with the additive that is common in many other additives. Therefore, the total additive package must be known to confirm that other additives present do not contain bands that would interfere with the measurement. The method is typically used for process control of additive addition and is not recommended for filled or pigmented resins. The sample must be pressed into a film or coupon prior to the analysis.
The document outlines a specific infrared spectroscopy method to determine the weight percentage of Irganox 3114 and chemically identical antioxidants in polypropylene. The technique relies on measuring the absorbance of a characteristic carbonyl band at 1696 cm⁻¹ relative to a reference polypropylene band at 4062 cm⁻¹.
The resin should be molded into a film with a thickness between 0.5 and 0.7 mm.
The absorbance of the additive's carbonyl band is measured at 1696 cm⁻¹, while the reference polypropylene band is measured at 4062 cm⁻¹.
The MicroLab PC FTIR software is used to set up peak measurements and perform automatic calculations.