Model of Stress–Strain Dependence for Poly(Vinyl Alcohol)‐Based Hydrogels

ABSTRACT The poly(vinyl alcohol), poly(vinyl alcohol)/chitosan, and poly(vinyl alcohol)/chitosan/gentamicin hydrogels, aimed for wound dressing in medical treatment of deep wounds, were prepared by physical cross linking using freezing–thawing method in five cycles. In order to investigate the mechanical properties of synthesized hydrogels, tensile test was performed and values of modulus of elasticity have been calculated from the experimental dependence between stress and strain. The general fractional derivative model for the stress–strain relation was proposed and compared with experimental measurements. The values of modulus of elasticity calculated from the proposed model corresponded very well with the values determined from experimental curves, confirming the validity of the proposed mathematical model of stress–strain behavior of synthesized poly(vinyl alcohol)‐based hydrogels. The new model was applied to the poly(vinyl alcohol)‐based hydrogels tested in quasi‐static extension. The final expression gives a new relation that is used to fit the experimental results. The least squares method was used to determine the optimal values of model parameters.