Abstract
Studies on the thermal decomposition of ammonium hypophosphite in nitrogen atmosphere under various conditions were carried out. The thermal decomposition products obtained were different from those in the literature.
The compositions of the products depended greatly on the conditions of decomposition. The products obtained at relatively low temperature (250°C) showed comparatively high concentration of orthophosphoric acid, and its value rapidly decreased with increasing duration and temperature of the thermal treatment, while the concentrations of the polyphosphoric acids, pyro-, tri-, tetra-, etc., increased. These were indicated not only by the increase of the total concentration of phosphorus pentoxide in the products, but also by the fractional elution of each polyphosphoric acid using ion-exchange resin, Dowex-1. Conclusively, it is assumed that a relatively large amount of orthophosphoric acid is produced in the early period of decomposition reaction and the dehydration reaction follows, of which rate is accelerated by the elevation of temperature.
