Aging processes limit the service life of elastomer components. Over the course of time mechanical-dynamic (fatigue), oxidation processes, temperature, exposition to UV light (photo oxidation) and to aggressive media lead to irreversible changes in the physical and chemical properties of an elastomer material. Functional failure of the component concerned can be the consequence. Oxidation reactions are responsible for the irreversible changes of properties. Alongside the selection of polymers, the aging process is determined mainly by the use of anti-aging agents – e.g. p-phenylene diamines (p-PPD`s). This paper focuses specifically on the time and temperature dependency or kinetic aspects of reaction mechanisms and the consumption of p-phenylene diamines with systematic variation of molecular structure. Of special interest are the efficiency of intermediates as antioxidants and the fate of the antioxidant. LC-MS-studies in model systems using squalene / p-PPD`s are carried out to identify pendant groups and further reaction products. The investigations are carried out by means of the chemiluminescence method especially in combination with FT-IR spectroscopy, extraction and chromatography (LC-MS, GC-MS).