The flameproofing phenomena of cellulose phosphate were analyzed by the thermal balance and the results obtained were as follows:
(I) The curves plotting weight loss vs. heating temperature about ammonium cellulose phosphate (1) were very different from the case of cellulose linter (2). The decomposition of (1) began at lower temperature than (2), but the continued decomposition curve of (1) increased more slowly than (2). It was almost impossible to prevent charring of cellulose fibre when it was directly exposed to flame, but the presence of phosphate radicals could prevent further burning after the fibre was withdrawn from the flame. It was recognized that the larger the degree of esterification, the larger the thermal stability.
(II) The thermal stability of cellulose phosphates depends upon their polymerization degree. When the degree of esterification is nearly equal, the sample possesed higher molecular weight is superior in thermal stability, and this state is obtainable at higher temperature and shorter duration of reaction.
(III) The ammonium salt and natrium salt of cellulose phosphates were very different from each other in weight loss curve, and it could be concluded that the former is better flameproofing than the latter.