Optimization of zero-shear viscosity for HPAM-Polystyrene microspheres formulations through experimental design approach

In this work, the reinforcing effects of polystyrene microspheres in a hydrolyzed polyacrylamide (HPAM) matrix was studied. The experimental design approach was used to optimize the rheological behavior of the HPAM polymer. The effects of three important parameters, including the size of the polystyrene microspheres, their concentration, and the test temperature on the zero-shear viscosity of HPAM polymer solutions were considered. The results showed that the size of the microspheres and test temperature were the most influential factors simultaneously. Moreover, the optimal zero-shear viscosity, at 20 °C, was predicted to be at microspheres concentration of 50 ppm and microspheres size of 1000 nm. The results showed close agreement between the predicted results by the RSM method and those obtained experimentally.