(169f) Hyperelastic Models for Studying Stress-Strain Curves of Processed Polymeric Systems with Supercritical CO2 Techniques

Supercritical drying and supercritical phase inversion are useful techniques for obtaining materials, such as aerogels or membranes, with different morphologies that can be used for biomedical applications. However, articles are focused on material morphology (pore or nanofibrous) without taking into account how the use of the supercritical fluids can affect the mechanical response of the obtained materials.

Therefore, this work studies the mechanical response of different microporous membranes (cellulose acetate-graphene oxide) and nanofibrous aerogels (alginate-gelatin) that were previously processed with supercritical carbon dioxide. Stress-strain curves were obtained with tensile and compression tests and the results were modeled with several hyperelastic equations. Modeling results (always with deviations less than 15%) indicated that hyperelasticity theory can be applied to this type of studies and that solids processed with supercritical CO₂ behave as hyperelastic materials. Based on the previous results, an hyperelastic model (Ogden) was used to perform a finite element model that can be used to predict accurately the behavior of these type of solids for future applications.