The direct determination of free acrylonitrile in aqueous copolymer latices. Part II. Use of a continuous-flow enthalpimetric analyser designed for the measurement of macro amounts

Abstract

The continuous-flow enthalpimetric analyser described is particularly suitable for measurement of the large temperature changes associated with the determination of reactants at high concentrations. Sample and reagent streams are metered in constant proportions through coils kept at constant temperature in a thermostat into a mixing vessel. The temperature rise of the solution at the exit of the mixing vessel is monitored by a thermistor bridge circuit and recorded on a strip-chart recorder. The apparatus can be used successfully even when reaction between sample and reagent is slow. This is demonstrated by the application described here for the determination of acrylonitrile monomer in aqueous polymer latices by reaction with sodium sulphite.