Comparative study of rheological properties of polyvinyl alcohol and polyethylene glycol

Abstract

Hydrogels are promising biomaterials for diverse applications that require studying their rheological properties. While some properties of hydrogels have been investigated, their comparative analysis for a deeper understanding of their rheological properties is required to determine their mechanical behavior. Polyvinyl alcohol (PVA) and polyethylene glycol (PEG) are among the hydrogels with diverse applications in engineering. This study aims to provide comparative data on their rheological properties. Both PVA and PEG showed steady shear viscosity as their viscosity did not show a huge change with time. Their shear viscosity increased with shear strain. PEG showed more shear thickening behavior than PVA. While the shear viscosity of PVA reached a plateau, that of PEG continued to increase. This was attributed to the sensitivity of PEG to its deformation because of the junction separations after the application of mechanical force on the polymer. Furthermore, the slow increase in the shear viscosity of both polymers was observed with the increase of the shear rate. This increase was 2.4 % for PVA and 8.7 % PEG, respectively. As these polymers are among the candidates for the preparation of nanocomposites, the results of this study can provide the required information for their applications in engineering.