ABSTRACT
The results of the comparison of Tg values obtained by different techniques show a significant difference between the values determined by physical and mechanical methods. As we have pointed out, an important role can be played both by the frequency in the mechanical measurements and by the loading. Besides, depending on the service conditions of elastomeric materials, they can be characterized by a low temperature boundary Tlow; this boundary is determined by the properties of the material itself and the level of the properties required to provide the operation of elastomeric goods. This issue will be considered in detail in Chapter 6; here we would only note that Tlow and Tg can differ significantly. Herewith,
(2.1)
is usually positive, i.e., Tlow is higher than Tg; for particular applications, however, the condition can be achieved when Tlow < Tg (see below and also Chapter 6).
