Effect of oxygen concentration on combustion residues of polymerised styrene-butadiene rubber 1502

Polymerised styrene-butadiene rubber (SBR) 1502 is one of the most common petrochemical products. During the identification of fire evidence, the combustion residues of SBR 1502 highly interfere with the identification of gasoline, a fire accelerant. By conducting thermogravimetric–differential scanning calorimetry (TG-DSC) experiments at various oxygen concentrations (0, 14, and 21 vol.%), the TG-DSC combustion characteristic behaviour of SBR 1502 was investigated. Gas chromatography–mass spectrometry was used to examine the combustion residues at different stages. The results indicated a lack of 2,3-dimethylnaphthalene among the combustion residue of SBR 1502 at the oxygen concentration of 0 and 14 vol.%, thus effectively avoiding the interference of this combustion residue in gasoline identification. The results of the quantitative analysis revealed aromatic hydrocarbon components as the most interfering components for all oxygen concentration and temperature. The combustion residues of SBR 1502 at different oxygen concentrations and combustion stages exhibited different degrees of interference in gasoline identification. Therefore, qualitative and quantitative analyses (hierarchical clustering analysis) were employed to eliminate interference from SBR 1502 in gasoline identification. The results provide theoretical support during the fire identification process.