Rheological Properties and Sedimentation Stability of Polyanionic Cellulose-Microbarite Compositions in Aqueous Medium
Aqueous dispersions of mixtures of low-viscosity polyanionic cellulose with microbarite are studiedby viscometry, rotational rheometry, dynamic light scattering, and laser microelectrophoresis. Owing tothe interaction of the polymer with microbarite particles, the hydrodynamic size of the particles and theirelectrophoretic mobility increase, which indicates the formation of polymer-colloidal complexes. In themode of semidilute polymer solutions, the introduction of microbarite additives is accompanied by a significantincrease in viscosity and the resulting compositions are sedimentation stable for 2 days. The frequency dependences of the storage modulus and the loss modulus show that complexation leads to a strong structuring of the system.