The direct determination of free acrylonitrile in aqueous copolymer latices. Part I. Rapid potentiometric titration method

Abstract

A rapid semi-automatic procedure for the direct determination of 0·05 to 15 per cent. of acrylonitrile monomer directly in aqueous butadiene-acrylonitrile latices is described. The determination is carried out without prior separation of the monomer and is based on the addition reaction of sulphite and acrylonitrile and subsequent potentiometric titration of the liberated alkali to a pre-set pH end-point.

Results reproducible to within ±2 per cent. relative are obtained on latex samples containing 15 per cent. of monomer, and with samples containing only 0·1 per cent. of free acrylonitrile the reproducibility is still within ±15 per cent. relative.