ISO 6528-2:1992

Rubber — Determination of total sulfur content — Part 2: Sodium peroxide fusion method

Is applicable to NR, CR, SBR, BR, IR, IIR, EPDM, NBR, and ebonite (see ISO 1629). The principle of the method is oxidation with sodium peroxide, conversion of sulfur to sulfate ions, and determination of the sulfate by gravimetric analysis as barium sulfate. The method is applicable for the determination of all the sulfur present in a rubber or rubber product, including that contained in barium sulfate which may be used as a filler.