Sulfur K-edge X-ray Absorption Near Edge Structure (XANES) measurements were used to monitor the processes occuring at the sulfur-crosslinks during high temperature oxidative aging for a number of SBR compounds. Variations included sulfur links of different type and density, filler material and use of antidegradants, We find a general mechanism of the aging process which is modified by each of the parameters mentioned above, Whereas antidegradants delay the thermooxidative aging without changing the aging resistance of the sulfur bonds we find that both the amount of S8/TBBS and the presence of carbon black in the sample enhance this parameter considerably.