Study of rheology

The branch of science related to the study of deformation and flow of materials was given the name rheology by Bingham, whom some call the father of modern rheology. The prefix rheo is derived from the Greek rheos, meaning current of flow. The study of rheology includes two vastly different branches of mechanics—fluid and solid. The polymer scientist is usually concerned with viscoelastic materials that act as both solids and liquids. 

Oparex 15 calcined calcium sulphate (Yesos Ibericos) was evaluated as a filler in plasticised PVC cable insulation compounds in comparison with two grades of calcium carbonate. Improvements were observed in tensile, electrical and low temperature properties, flammability and heat ageing characteristics and chemical resistance for calcium sulphate filled compounds, while no significant differences in water absorption and hydrolysis were noted. Studies of rheological properties showed improved processability in mixing and extrusion trials. URALITA... 

Rheological properties of mayonnaise have been studied using different rheological techniques steady shear rate-shear stress, time dependent shear rate-shear stress, stress growth and decay at a constant shear rate, dynamic viscoelastic behavior, and creep-compliance viscoelastic behavior. More studies have been devoted to the study of rheological properties of mayonnaise than of salad dressings, probably because the former is a more stable emulsion and exhibits complex viscous and viscoelastic rheological behavior. 

Physicochemical studies of the regularities of foaming and formation of cellular structure in foams, studies of rheological and thermodynamic parameters of foaming and of the mechanism of interactions between components, etc. 

Therefore, the study of rheological properties, the determination of the activation energy of viscous flow, composition-fluidity relationships, and key factor effects of the lubricity-promoting additive on the fluidity of oligoethylsiloxane-based compositions were of interest. 

Study of Rheological Properties of Oligoethylsiloxane-Based Compositions 663... 

There are two main streams in the study of rheological properties of suspensions and polymeric solutions. One is the hydrodynamic approach/ and the other is the molecular kinetic investigation. The so-called Ree-Eyring equation is a result from the latter category it is written as follows ... 

Several methods were applied in the studies of rheological properties of paste those based on the acoustic wave velocity, as well as on the measurements of resistance against the force in of penetrator (similar to Vicat apparatus for setting time measurements), also based on the pressure transfer in the paste and different rotation methods with spindle and finally viscometers with co-axial cylinders [5]. 

Increased content of negative-charged sulfonic groups imparts a stable phase state of dilute aqueous dispersions of ANP. Study of rheological properties of aqueous dispersions also showed that with the increase in concentration the viscosity rises, and the 7—8% ANP dispersion has a gel form. Furthermore, the presence of acidic functional groups in the ANP contributes immobilization of bioactive substances containing basic functional groups. 

Preparation of cryogels [297] based on the self-assembled dipeptide molecules, study of rheological properties and macroporous morphology of resulting cryogels... 

Study of rheological properties and oscillatory shear flow... 

---