Figure 9b compares the complex viscosity (from dynamic parallel-plate experiments) with the
absolute viscosity determined using the sliding plate and capillary rheometers for representative polymers of Series 2 (various molecular weights).
The
absolute viscosity for Schiff bases and Resins improved with the escalation in concentration and decline with increase in temperature.
Similarly empirical relations were established between temperature and
absolute viscosity for lubricants derived from seed oils [10].
The UHMWPO has a weight-average molecular weight of 3,500,000 to 10,500,000 g/mol and an
absolute viscosity of 5 to 45 dL/g.
For liquids, it corresponds to the informal concept of thickness [4],also viscosity known as kinematic viscosity,
absolute viscosity or simple viscosity and defined mathematically as the ratio of the shearing stress to the velocity gradient in a fluid [5], due to Newton's equation for fluids, which similar to Newton's second law of motion [6] as follows:
[C.sub.1] presents the
absolute viscosity while [C.sub.2], [C.sub.3], and [C.sub.4] are fitting parameters.
