Comparison of determination methods of soap and organic acid in styrene-butadiene rubber

The contents of soap and organic acid in emulsion polymerized styrene-butadiene rubber determined by indicator titration and potentiometric titration in ISO 7781 were compared. The differences between the determination principles and results of the two methods were compared, and the accuracy of the results was investigated by standard addition experiment. The results showed that the results of potentiometric titration and indicator method were consistent. When testing the soap content in emulsion polymerized styrene-butadiene rubber, the indicator method was greatly affected by amine antioxidant and filling oil. But the potentiometric titration method was less affected by amine antioxidant and was not affected by filling oil, so the determination result was more accurate.