This method is for the determination of Irganox 1010 and chemically identical antioxidants in polyethylene where the additive package is known. The method utilizes a characteristic ester 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.
This document describes an analytical method for determining the weight percentage of Irganox 1010 and chemically identical antioxidants in polyethylene. The method utilizes a characteristic ester carbonyl band at 1745 cm⁻¹ relative to a reference band at 2019 cm⁻¹, requiring known additive packages to avoid interference.
The procedure involves molding the resin into thin films (0.5 to 0.7 mm) and analyzing them using an Agilent Cary 630 FTIR spectrometer equipped with DialPath or TumblIR accessories. The analysis uses MicroLab PC software to calculate peak ratios, which are then converted to concentration via a linear regression calibration equation.
The sample must be pressed into a film or coupon with a thickness between 0.5 and 0.7 mm.
The absorbance of the additive band is measured at 1745 cm⁻¹ and the reference band at 2019 cm⁻¹.
The Agilent DialPath or TumblIR accessories are used to insert the film into the infrared beam path.