Properties of Soda Aluminosilicate Glasses: V, Low‐Temperature Viscosities*

The low‐temperature viscosities of two series of sodium aluminosilicate glasses were measured by the fiber elongation method. The results suggested that a modification of the Day and Rindone structural model for sodium aluminosilicate glasses was necessary. The modified model suggests that additional (AlO ½ ) − groups form at Al/Na ratios >1.