Rheological Characterization of Polymers in Presence of Supercritical CO₂: Applications in Polymer Processing and Modification
Matthias Walluch, Monika Winkler, Daniela Schwarz
This study investigates the use of Anton Paar's pressure cells in combination with an MCR rheometer to analyze the high-pressure rheological behavior of polymers under supercritical carbon dioxide (CO₂) conditions. Designed to simulate industrial environments, the pressure cells operate at up to 400 bar and 300 °C, enabling detailed evaluation of polymer processing, oil recovery, and food-related applications.
The research focuses on the role of CO₂ as a plasticizer and processing solvent, examining its influence on key rheological properties such as viscosity, melting point, and internal structure in polymer systems like Polylactic Acid (PLA), High-Density Polyethylene (HDPE) and others. Preliminary results indicate that CO₂ significantly modifies polymer behavior by reducing viscosity and lowering melting points, compared to tests performed in nitrogen atmospheres. These changes enhance the processability and flow properties of the materials, particularly under supercritical conditions.
The findings highlight the critical role of high-pressure rheological measurements in optimizing polymer modification, foaming, and blending processes. By revealing how CO₂ interacts with polymers under extreme conditions, this study provides a foundation for advancing both material performance and industrial processes. Further research will expand our understanding of CO₂’s effects across diverse polymer systems and processing parameters, offering valuable insights for industrial applications.