Poly stress-strain diagram

Another example of the use of polarized radiation in imaging studies is the analysis of poly(vinylidene fluoride)(PVDF) films, which have been uniaxially elongated at different temperatures. Depending on the thermal, mechanical and electrical pretreatment, PVDF can exist in different modifications [59]. The crystal structure of the cmmpled 11(a) modification can be converted into the aU-tra s 1(P) form by tensile stress below 140°C (see Figure 9.27a). Figure 9.27b shows the stress-strain diagrams of PVDF films in the 11(a) form which have been elongated to 400 % strain at 100 and 150°C. The observed decrease in stress upon elevation of the... 

Figure 11-15. Stress/strain diagram of a natural rubber (above) and an it-poly(styrene) (below) at room temperature. Left experimental curves right true stress curves. Numerical values were not given for the lower left figure in the original work. (After P. I. Vincent.)...

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