Scaling equation for viscosity of polydimethylsiloxane in ethyl acetate: From dilute to concentrated solutions

Rheology of polymer solutions suffers from lack of universal model of viscosity applicable across wide range of concentrations. Here we build such a model on the basis of measured viscosity of polydimethylosiloxane (PDMS) in ethyl acetate in a wide range of polymer concentrations: from dilute up to highly concentrated solutions. The relationship between viscosity and different polymer parameters in solution such as coil size, correlation length xi, monomer-solvent and monomer-monomer interaction parameter were established experimentally as a function of concentrations [from 0.001 g/cm(3) to 8.000 g/cm(3)], temperature [in a range 283-303 K] and molecular masses [9-139 kg/mol]. Entanglement onset at the crossover from dilute to semi-dilute solution as well as the solvent-monomer contact reduction at the crossover from semi-dilute to concentrated regime are captured by the model. This model is in accordance with the Eyring rate theory for activated processes.