Abstract:

The content of Irganox 3 114 in polypropylene was quantitatively analyzed by Fourier⁃transform infrared （FTIR） spectroscopy， and its characteristic absorption peak was determined at 1 695 cm^-1. Meanwhile， the FTIR spectrum shows a quantitative absorption peak for PP at 4 059 cm^-1 through comparing the infrared spectral information of Irganox 3114， PP， and PP/Irganox 3114 blend. By taking 1/A₄₀₅₉ as the thickness standardization factor， A₁₆₉₅/A₄₀₅₉ as the horizontal coordinate， and 3114 content as the vertical coordinate， the standard curve of Irganox 3114 was established. The results indicated that the content of Irganox 3114 had a good linear relationship with A₁₆₉₅/A₄₀₅₉， and its linear correlation coefficient was 0.999 28. The effect of thickness standardization factor was verified， and the sample thickness had no influence on the determination result of the content of Irganox 3114 over the experimental range. The relative standard deviation of this method is less than 1.30 % for the determination of Irganox 3114， and its precision is good. The absolute relative error of Irganox 3114 in standard substance is less than 3.27 %， and the accuracy of this method is higher.

Key words: infrared spectroscopy, polypropylene, irganox 3114