A Study of Sodium–Copper and Sodium–Nickel Polyphosphate Glasses by Differential Scanning Calorimetry1

Sodium polyphosphate and sodium–copper and sodium–nickel copolyphosphate glasses (with the ratio Na : M = 9 : 1 and 8 : 2, where M is Cu or Ni) are studied. The glass transition (Tg) and melting (Tm) temperatures are determined by differential scanning calorimetry (DSC). It is revealed that the Tgand Tmtemperatures depend on the molecular weight Mt(determined from terminal groups) of polymeric glasses, the Na : M ratio, and the glass synthesis conditions. The activation energies are calculated, and the thermodynamic parameters ΔH, ΔS, and Cpare measured.