The Constitution of the Sodium–acid Phosphate Glasses

Abstract

ABS'TIIACTThe preparation of phosphate glasses containing sodiu~il and hydrogen is described. The over-all con~position was calculated from the N a / P ratio of the starting mixture and the 11)-drogen content determined by a zinc oxide ignition. The chemical constit~~tioii was determined paper-chromatographically eiilploying recent improvenients in techniclue.Close resemblance between the molecular weight distributions of the sodium-acid glasses and the strong phosphoric acids is shown by the results, but it is also shown that there is no sharp transition to the molecular weight distribution sho\vn by the sodiunl, potassium, and lithiunl glasses.'The importance of stoichionietry 011 the constitution of glass is discussed, together with the statistical ~nodels from which several theories are deri\,ed to predict the distribution of the polymers in a glass. The theories of Van Wazer and Parlcs, which show the most satisfactory agrectuent with the experinrental results, receive detailed consideration.

Molecular - weight distribution in Graham's salt: Dependence on conditions of formation

“…Earlier, Van Wazer and his associates (3) and Westman et al (4)(5)(6)(7)(8) studied in detail the distribution of molecular weights in polyphosphates. Their studies, however, do not throw much light on the effect of the conditions of preparation on the molecular weight distribution.…”