Analytical method for determination of butadiene and styrene contents of styrene-butadiene rubber vulcanizates without pretreatment using pyrolysis-gas chromatography/mass spectrometry

Styrene-butadiene rubber (SBR) vulcanizates were prepared using various emulsion SBRs (ESBRs) and solution SBRs (SSBRs) with different microstructures, and were pyrolyzed without pretreatment. Principal pyrolysis products of SBR vulcanizates are butadiene and styrene. Butadiene and styrene contents of the SBR vulcanizates were determined using plots of the relative peak intensity ratio of butadiene/styrene as a function of the molar ratio of butadiene and styrene of the raw SBRs. The peak intensity ratio on the whole increased as the butadiene content increased. The correlation was enhanced by correction with the butadiene/styrene molar ratio of raw SBRs. For the plot of SSBR samples, the correlation was more enhanced by correction with the 1,2-unit/styrene molar ratio of raw SBRs. By using the corrected plots, butadiene and styrene contents of unknown SBR vulcanizates could be determined.