•   Molecular Weight
•   Viscosity
•   Thermodynamics
•  Mechanical Properties
•  Modeling

 

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Viscosity is used to determine molecular weight; as the molecular weight increases, there is increased opportunity for chain entanglement and this increases the resistance to flow.

"Viscosity of Linear Polyesters. An Exact Relationship between Viscosity and Chain Length" - by Paul J. Flory

Viscosity is a function of:

η₀, viscosity of the solvent

ρ₀, density of the solvent

ρ, density the solution

n, number density of particles



R, radius of the "drain"

, shear rate

kT, thermal energy (Boltzmann constant multiplied against temperature)

t, elapsed time


Poiseuille's equation relates viscosity to drain time.

Several equations for viscosity include:

Intrinsic viscosity

Relative viscosity