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The WLF equation is a consequence of time–temperature superposition (TTSP), which mathematically is an application of Boltzmann's superposition principle. It is TTSP, not WLF, that allows the assembly of a compliance master curve that spans more time, or frequency, than afforded by the time available for experimentation or the frequency range ...
The empirical relationship of Williams-Landel-Ferry, [10] combined with the principle of time-temperature superposition, can account for variations in the intrinsic viscosity η 0 of amorphous polymers as a function of temperature, for temperatures near the glass transition temperature T g. The WLF model also expresses the change with the ...
The practical application of this idea arises in the Williams–Landel–Ferry equation. Time-temperature superposition avoids the inefficiency of measuring a polymer's behavior over long periods of time at a specified temperature by utilizing the Deborah number.
If the melt of an (organic) amorphous polymer is cooled down, it solidifies at the glass-transition temperature T g. On cooling, the hardness of the polymer increases in the neighborhood of T g by several orders of magnitude. This hardening follows the Williams-Landel-Ferry equation, not the Arrhenius equation.
At low shear rate (˙ /) a Carreau fluid behaves as a Newtonian fluid with viscosity .At intermediate shear rates (˙ /), a Carreau fluid behaves as a Power-law fluid.At high shear rate, which depends on the power index and the infinite shear-rate viscosity , a Carreau fluid behaves as a Newtonian fluid again with viscosity .
The Flory–Fox equation relates the number-average molecular weight, M n, to the glass transition temperature, T g, as shown below: =, where T g,∞ is the maximum glass transition temperature that can be achieved at a theoretical infinite molecular weight and K is an empirical parameter that is related to the free volume present in the polymer sample.
Williams' PDH facility in Canada will have the capability to initially produce up to approximately 1.1 billion pounds (500 kilotonnes) annually of polymer-grade propylene, with the opportunity to ...
John Douglass Ferry (May 4, 1912 – October 18, 2002) was a Canadian-born American chemist and biochemist noted for development of surgical products from blood plasma and for studies of the chemistry of large molecules.