Effects of Volume Fraction and Composition on the Rheological Properties of Polyacrylic Acid/Polyacrylamide Hydrogels

Abstract

Polyacrylamide-based hydrogels are popular materials that have been extensively studied for their applications in the field of biomaterials due to their permeability and biological compatibility. A major limitation of this polymeric material, however, in biological applications stems from their limited mechanical stiffness. The current study examines the mechanical properties of polyacrylamide-polyacrylic acid-based hydrogels at varying volume fractions and compositions using oscillatory rheology. For a fixed chemical cross-linker concentration, an increase in the volume fraction of hydrogel resulted in an increase in the shear elastic modulus of the hydrogel. Additionally, varying the relative ratio of polyacrylamide to polyacrylic acid resulted in modest changes in the shear elastic modulus.