Modular lab-scale devolatilizer for in-situ investigation of polymer–volatile separation

A compact, modular falling-strand devolatilization apparatus has been developed to investigate polymer–volatile separation under controlled laboratory conditions. The setup combines interchangeable 3D-printed plates, relocatable oxygen probes, and a transparent polycarbonate column, enabling both hydrodynamic reconfiguration and direct visualization of foam dynamics. Silicone oil with dissolved oxygen was used as a model system to examine the effects of operating conditions and internal geometries on devolatilization. Results show that internal structures strongly influence residence time and flow morphology, thereby enhancing volatile removal compared to free-fall. Measurements of foam height and local oxygen concentration provide spatially resolved data. To rationalize the observed trends, we introduced a composite dimensionless group that incorporates supersaturation, and residence time, providing a unified framework to interpret the fundamental mechanisms governing devolatilization. Beyond polymer devolatilization, the system offers a versatile platform for studying bubble-driven mass transfer in viscous media and for testing process designs in an accessible laboratory environment.