Compatibility of medical-grade polymers with dense CO2

This study reports the effect of exposure to liquid carbon dioxide on the mechanical properties of selected medical polymers. The tensile strengths and moduli of fourteen polymers are reported. Materials were exposed to liquid CO2, or CO2 + trace amounts of aqueous H2O2, at 6.5 MPa and ambient temperature. Carbon dioxide uptake, swelling, and distortion were observed for the more amorphous polymers while polymers with higher crystallinity showed little effect from CO2 exposure. Changes in tensile strength were not statistically significant for most plastics, and most indicated good tolerance to liquid CO2. These results are relevant to evaluating the potential of liquid CO2-based sterilization technology.