Williams-Landel-Ferry equation

[Wyb]

I'd like to use the Williams-Landel-Ferry equation to create a mastercurve.

I'd like to have a frequency range of 1 to 1000Hz at 23 degrees. The DMA machine has a frequency range of 1 to 200Hz. Therefore, I did a temperature sweep from 23 to 140 degrees Celsius. I think I made an error here. I think I should have decreased the temperature (-50 degrees Celsius to 40 degrees or so). Could anyone explain this?

I've got a second question about the WLF equation: How do I calculate C1 and C2?

log at = - C1 (T-T0) / (C2 + T - T0).

Is in this equation T0 the temperature I want to make the master curve for (so in my case 23 degrees)?

And is the shift factor at a time, so I can simply use a fast fourier transform to go to the frequency domain?

Thank you for your response

 

[Compositepro]

The WLF equation is a time temperature correlation that basically says that things happen faster at higher temperatures. If your DMA operates up to 200 Hz and you want to predict how a material would behave at 1000 Hz you need to cool the material. That is, behavior at 1000 Hz and 23C is equivalent to its behavior at 200 Hz at some colder temperature. That's as much as I know.