Non-Linear Rheological Properties and Neutron Scattering Investigation on Dilute Ring-Linear Blends

Linear and non-linear Rheology on dilute blends of polystyrene ring polymers in linear matrix is combined with Small Angle Neutron Scattering (SANS) investigations. In this way 2 different entanglement interactions become clear. After stretching the samples to different hencky strains up to 2 in a filament stretching rheometer, followed by quenching, strong anisotropic scattering patterns were obtained which were described by affinely deformed rings which function as giant, polymeric chemical crosslinks or sliplinks and more or less isotropic topological contributions from the entangling with interpenetrating linear chains.

At the same time the non-linear rheological and mechanical data fit to a non-affine slip-tube model as for moderately crosslinked networks and to interchain pressure models or a modified non-linear Doi-Edwards description for the observed strain hardening during the extensional rheology. The entangled situation is thought to be responsible for the different terminal behaviour observed in ring polymers with traces of linear impurities.

A comparison with a dilute blend of a linear chain of the same size as the ring polymer in the longer matrix is made.