1. 1 Dynamic Mechanical Analysis B&R Ch. 16.5-16.7, Fried 5

2.  ’,  ”& tan  2

3. Torsion Pendulum 3

4. 4

5. Forced vibrational mode 5 (Linear Variable Differential Transformer)

6. Simple models of viscoelastic behavior B&R Ch.15, Fried 5.1.2 Maxwell Voigt 6

7. Multi-element models Maxwell-Wiechert Voigt-Kelvin Four-parameter model 7

8. Time-Temperature Superposition Shift factor, a T WLF relationship 8

9. Williams-Landel-Ferry Eqn. We can see from the master curve of polyisobutylene (PIB) that the time to relaxation where the modulus is 10 6 dyn/cm 2 is about 10h at 25°C. Given that PIB has a T g = -70°C, determine the time necessary to reach the same modulus at a temperature, T = -20°C. 9

10. Regions of viscoelasticity 1.Glassy 2.Leathery 3.Rubbery plateau 4.Rubbery flow 5.Viscous flow 10 Stress-relaxation of NSB polyisobutylene

11. Molecular weight, crosslinking & crystallinity Molecular weight (chain length) Crosslinking Crystallinity 11 Infinitely long polymer chains

12. 12