Study on the rheological testing method of water soluble hydrophobically associating polymersⅡ: zero-shear viscosity

A suitable rheological model, the Carreau-Yasuda Model, which could well fitting zero-shear viscosity of hydrophobically associating water-soluble polymer（HAWSP） solution was determined by comparisons among three models and the factors that effect the measure of zero-shear viscosity testing has been discussed, which includes pre-shearing program and load method of force.The minimum shear stress of sweep range was one order lower than yield stress and the load time of stress was about 1200 seconds under the condition of lab experience with pre-sheared of 3 to 5 minutes and shear rate from 20 to 500 s-1 and the following hold up time in the range of 5 to 80 minutes. After the treatment the average errors of zero-shear viscosity replicate determination of HAWSP solutions with different viscosity at Physica MCR301 rheometer are smaller than 3% by setting reasonable rheometry program.