THE CONSTITUTION OF THE SODIUM–ACID PHOSPHATE GLASSES

Abstract

The preparation of phosphate glasses containing sodium and hydrogen is described. The over-all composition was calculated from the Na/P ratio of the starting mixture and the hydrogen content determined by a zinc oxide ignition. The chemical constitution was determined paper-chromatographically employing recent improvements in technique.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 shown by the sodium, potassium, and lithium glasses.The importance of stoichiometry on the constitution of glass is discussed, together with the statistical models from which several theories are derived to predict the distribution of the polymers in a glass. The theories of Van Wazer and Parks, which show the most satisfactory agreement with the experimental results, receive detailed consideration.