Thermal dehydrochlorination and stabilization of poly(vinyl chloride) in solution: Part 1—Conditions for reliable experimental data

Abstract

The detection of the HCl evolved on dehydrochlorination of poly(vinyl chloride) in trichorobenzene solution was carried out by coulometric titration; this method is not affected by the solvent carried by the stream of inert gas into the titration cell. This allows the use of a minimum path between the reactor and the titration cell so that the major source of error, which is the adsorption and desorption of HCl on, or from, the glassware, is practically suppressed. The shape of the dehydrochlorination kinetic curve changes from linear to concave downward, when the temperature is increased from 175°C to 195°C; between these temperatures a sigmoidal shape is observed.