Influence of processing parameters on the macroscopic mechanical behavior of PVA hydrogels

- Experimental characterization of PVA hydrogels
- Immersed mechanical testing in a thermo-regulated solution
- Mechanical response to a load case of hydrogels synthetized using different elaboration parameters
- Hyper-elastic modeling of the material response of the PVA hydrogel
- Deduction of the density of macro-molecular chains from the mechanical response

This paper investigates the influence of three different processing parameters on the global mechanical behavior of PVA (Polyvinyl alcohol)/DMSO (Dimethylsulfoxide) hydrogels: the initial concentration of PVA, the DMSO:H2O ratio and the number of freeze/thaw cycle applied to the material. A specific thermo-regulated testing apparatus for hydrophilic materials is presented, along with the performed cyclic and rupture tests. The observed mechanical responses are explained by an in-depth analysis of the cross-linking phenomenon. Using the Neo-Hookean hyperelastic model, the experimental data is fitted and a link between the density of macro-molecular chains in the material and its mechanical behavior is established. Strong differences are observed and discussed.