Influence of the shear rate, of the molecular architecture and of the molecular mass on the critical overlapping concentration c*

The critical overlapping concentration c * has been studied in the dynamic state (by viscometry) and in the static state (by light scattering). An increase of the shear rate of the solution provokes an increase of c * in the case of linear polymers. In the case of a highly branched polymer the shear rate has no influence on its critical concentration. The scaling law between c * and the molecular mass for a given polymer—solvent system presents two different exponents, depending on the molecular mass region of the polymer.