A novel approach to plasticizer content calculation in an acrylonitrile-butadiene rubber real-time aging study (NBR)

This study presents an analysis of plasticizers and other additives in elastomers using several techniques to obtain relevant information for aging investigations. Thermogravimetric quantification of polymeric matrix, polymeric matrix char, carbon black, inorganic substances, plasticizers and other additives is commonly used. However, the thermogravimetric weight loss attributed to plasticizers and other additives contains additional components whose contribution to the weight loss has not been considered. Unreported components include water and carbonyl sulfide, which develop over long-term elastomer aging, and should be separately accounted for. This study employed Karl-Fischer oven techniques for calculating water content and linked thermogravimetric analysis with Fourier-transform infrared spectroscopy to measure carbonyl sulfide. Chromatoprobe-GC/MS was used to determine the ratio between rubber-related substances and JP-8 fuel and its additives, which can diffuse into rubbers. In fuel bladders, this occurrence is frequently observed, and the ratio consistently decreases over time.