Total ethylene content (TEC) is an important indicator for evaluating the impact strength of impact polypropylene copolymer products. It provides guidance for controlling parameters such as feed ratio, copolymerization time, and feed rate in processing. Currently, the measurement of ethylene content by Fourier transform infrared (FTIR) spectrometry is the most widely used method in the industry because of its high speed, excellent repeatability, and the wealth of information it provides. In this paper, a method based on FTIR spectroscopy and a standard curve for determining the TEC is proposed, and the sensitivity of the method under various conditions is analyzed. Precision evaluation on standard samples with known TEC indicates that the proposed method achieves a bias of –0.09 and an RMSE of 0.26. Furthermore, sensitivity analysis shows that when the sample thickness error is within 5μm, the error in TEC determination is less than 0.3%, and when the peak area error in the 707–750 cm⁻¹ region is within 0.006, the error is less than 0.006%. This method is currently applied at the Sino–Korean Petrochemical Analysis Center and plays an important role in providing accurate analytical data, guiding process production, and enhancing product market competitiveness.

Chunmiao Jiang. Determination and Sensitivity Analysis of Total Ethylene Content Based on Fourier Infrared Method. Academic Journal of Materials & Chemistry(2025), Vol. 6, Issue 2: 37-42. https://doi.org/10.25236/AJMC.2025.060205.

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