Linear empirical, phase characterization

Summarizing one can conclude that due to the empirical linear relationship between H and Tg in a rather broad range of Tg (-50 up to 250°C) which covers most commonly used polymers of the polyolefin-type and also polyesters and polyamides, it is possible to calculate the microhardness value of any amorphous polymer provided its Tg is known H =. 91Tg - 571). Furthermore, one can account for the contribution of soft liquid-like components and/or phases (characterized by a negligibly small microhardness) to the microhardness of the entire system. As we shall see in Chapter 5 the plastic deformation mechanism of such systems is different from that when all the components and/or phases are solid, i.e. have Tg above room temperature. 

As demonstrated above, there is hardly any doubt regarding the existence of a linear relationship between Tg and the microhardness Hoi amorphous polymers characterized by dominating single, mostly C—C bonds in the main chain. This empirically derived analytical relationship (Eq. (13.8)) makes it possible to account quantitatively for the contribution of the soft component and/or phase to the overall microhardness of multicomponent and/or multiphase systems as demonstrated above. 

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