Rheological properties of particle suspensions in a polymeric liquid

The rheological characteristics of a particle-suspended Boger fluid are reported. Non-shear thinning, highly elastic polymer solutions were obtained from a mixture of high-molecular-weight polyisobutylene (PIB) and low-molecular-weight polybutene (PB). Kaolinite was chosen as the suspended particles. The shear viscosity and first normal stress difference of the kaolinite-suspended PIB/PB solution exhibit characteristics similar to those of Boger fluids. In contrast to polymer melts with nearly spherical particles, the elasticity of this system increases with the addition of particles, and a qualitative interpretation based on PB (the solvent) as a 'shielding' agent is given. (C) 1999 Elsevier Science Ltd. All rights reserved.