Performance enhancement of PEBAX using supercritical fluid extrusion for biomedical applications

An intravascular catheter system requires design specifications that needs to provide sufficient flexibility, to follow desired path required by the surgeon and adequate stiffness to travel along the curving path of vasculature. This paper presents the effects of sub-supercritical, near-supercritical and beyond supercritical carbon dioxide assisted extrusion process and their characterization to evaluate their thermal and dynamic mechanical properties using Pebax. A twin-screw-extruder using scCO2 can effectively generate foams, while providing excellent control over mechanical and thermal properties. The crystallization and melting behaviour of scCO2 assisted extrudates were investigated using differential scanning calorimeter technique (DSC) for various isothermal conditions. The mechanical performance was evaluated by using dynamic mechanical thermal analysis (DMA) and tensile test. A significant increase in dynamic modulus was observed for Pebax extruded at 800 psi and 1000psi, however, decreased resilience and toughness was noted for Pebax extruded at 1200psi.