Study the Rheological Properties of Non-Newtonian Polymer Solutions and Solid Suspensions

Manar Taher Nasser
Dr. Kamal Shakir Abdul Masih

This research deals with experimental study of the rheological behavior of polymer solutions, solid suspension and the effect of adding polymers to solid suspensions. All polymers studied in this work are water soluble and used in industries as a rheology control additive (rheology modifiers), these are: CMC-Carboxymethyl cellulose, XCXanthan Gum, HEC-Hydroxyethyl cellulose and PVA-polyvinyl alcohol. Solid suspensions used are: Bentonite,Graphite and Corn starch.The rheological properties of these materials were investigated using a Couette coaxial cylinder rotational viscometer Fann model 35A with range between 3-600 rpm; by measuring shear stresses versus shear rates (i.e.Flow curve).Seventy Six runs were performed with the range concentration for all polymer solutions used: CMC, HEC, XC (4-40) g/L,PVA (2-10) g/L and the range concentration of solid suspensions: Bentonite 50-120 g/L,Graphite 30-90 g/L and Corn Starch 300800 g/L. The range temperature for runs: 055°C It was found that as polymer concentration was increased, the flow behavior index (n)decreased, and the range of n was between 0.7-0.4 at 20°C. Increase the concentration of solid suspension the flow behavior index (n), the range of n was between 1-1.3 at 35°C. Correlations were developed that describe the effect of polymer solutions and solid suspensions concentration on flow behavior index for each material used in this study and presented in a linear form.The viscosities of three polymers CMC, XC and HEC were decreased with increasing temperature and shear rate. It was found that XC polymer was more affected by concentration than other polymer used in this study and it has higher viscosity than other polymer used.It was found that the viscosities of solid suspensions were increased with increasing shear rate. The flow curve of experimental polymer solution and solid suspension was studied using the power law model.The variations in temperature influence the value of n and k. The increases in temperature cause are increase in flow behavior index (n) and decrease in concsistency index (k).By using the Solver Add-in in Microsoft Excel, the Bingham plastic model was found to be the best fits the experimental results of adding polymer to solid suspensions (PVA to Bentonite suspensions).