Problems of compatibility of the values of glass transition temperatures published in the world literature

The influence of different factors (primarily, the temperature-time conditions for preparation and measurement of samples) on the glass transition temperatures determined from the temperature dependences of properties is analyzed using the calculations performed in terms of the relaxation theory of glass transition. The most optimum conditions for measurement of the glass transition temperatures T g that ensure the compatibility of the values of T g obtained by different researchers are recommended. The validity of the assertion that the glass transition temperature T g is a temperature at which the viscosity of glasses is equal to 1013 P is considered.