Plumbers putty is an example, but it also shows the characteristics of silly putty. This equation tells you that as temperature increases, viscosity decreases exponentially. If motor oil does not behave this way, then it behaves in an unusual manner. Motor oil, in fact, does behave in an unusual manner. Let me try to explain how this is accomplished.
Oil contains polymer molecules in a solvent.
The molecules do not like the solvent all that much, so they tend to ball up or coil somewhat tightly on themselves. As the temperature is increased, the interaction between solvent and polymer changes. The polymer begins to like the solvent, so it uncoils. The polymer molecules then become entangled in one another, raising the viscosity, which counteracts the normal decrease with increasing temperature. The structure ofPP is shown in Table 6.4-1.