UW-Madison polymer processing (EPD650): lesson 4, part 5.

The final part of lesson four examines the temperature dependence of apparent viscosity, first normal stress coefficient and linear viscoelastic parameters G' and G''. The concept of time temperature superposition is introduced and an example given in terms of low density polyethylene. The shift factor, aT, is found to follow the activation energy approach, demonstrating it is possible to infer temperature dependence over a wide range of temperatures from just a single set of data.