Rheological Behavior of Binary Aqueous Solutions of Poly(ethylene glycol) of 1500 g.mol-1 as Affected by Temperature and Polymer Concentration

The rheological behavior of poly(ethylene glycol) of 1500 g.mol(-1) (PEG1500) aqueous solutions with various polymer concentrations (w = 0.05, 0.10, 0.15, 0.20 and 0.25) was studied at different temperatures (T = 283.15, 288.15, 293.15, 298.15 and 303.15) K The analyses were carried out considering shear rates ranging from (20 to 350) s(-1), using a cone-and-plate rheometer under controlled stress and temperature. Classical rheological models (Newton, Bingham, Power Law, Casson, and Herschel-Bulldey) were tested. The Power Law model was shown suitable to mathematically represent the rheological behavior of these solutions. Well-adjusted empirical models were derived for consistency index variations in function of temperature (Arrhenius-type model; R-2 > 0.96), polymer concentration (exponential model; R-2 > 0.99) or the combination of both (R-2 > 0.99). Additionally, linear models were used to represent the variations of behavior index in the functions of temperature (R-2 > 0.83) and concentration (R-2 > 0.87).