Читать книгу The Rheology Handbook - Thomas Mezger - Страница 174

The advantage of a fitting function is that it can be used to characterize the shape of a whole measuring curve using only a few model parameters, although the curve actually may consist of a large number of individual measuring points. A variety of viscosity/temperature fitting functions are mentioned in specialized literature, e. g. in ASTM D341, DIN 51563 and DIN 53017 [3.69]. As an example, explained is below the Arrhenius relation which usually is used for low-viscosity liquids.

For “Mr. and Ms. Cleverly”

The relations described here only apply to thermo-rheologically simple materials , i. e. materials, which do not change their structural character in the observed temperature range. Therefore, they do not change from the sol state to the gel state or vice versa (see also Chapter 8.2.4a, Note 1). In the temperature range which is related to practice, most polymer solutions and polymer melts are showing thermo-rheologically simple behavior. However, this applies usually not to dispersions and gels.