Abstract
The soap titration method of determining average particle sizes in synthetic latexes has been modified so as to make it applicable to natural rubber latexes. The method consists essentially in determining the distribution of an added detergent (sodium dodecyl sulfate) between the rubber and aqueous phases at a pH of approximately 6.0, the total dodecyl sulfate concentration being just sufficient for the formation of micelles in the aqueous phase. The average particle sizes of nine ammoniated latexes have been measured, including centrifuged and electrodecanted concentrates, two clonal field latexes and a sample of latex skim.