The influence of various heat-treatment on the viscosity, transformation temperature and electric conductivity of some soda-silica glasses in the immiscibility region was investigated. Two distinct temperature regions were found for several glasses. In one of the regions, heat-treatment leads to the " droplet " structure, whereas in the other it leads to the " two-framework " structure. The boundary between these regions was attributed to the boundary line of the spinodal region. A noticeable decrease in the transformation temperature of low-viscosity phase was found for the glass with a discontinuous low-viscosity phase. The uniform tension in droplets was assumed to be the cause of this effect.

No abstract