(291d) Macromolecular Engineering of Formulations: Rheology, Stringiness, Spinnability, and Printability
AIChE Annual Meeting
2021
2021 Annual Meeting
Materials Engineering and Sciences Division
Area Plenary 1: Emerging Areas in Polymer Science and Engineering (Invited Talks)
Tuesday, November 9, 2021 - 2:00pm to 2:30pm
Using DoS rheometry protocols that involve visualization and analysis of capillary-driven thinning and pinch-off dynamics of a columnar neck formed between a nozzle and a sessile drop, we elucidate the stretched polymer hydrodynamics underlying observed rheological response and on stringiness, printability, gloopiness, spinnability and processing behavior of polymeric complex fluids. We find that the extensional relaxation times exhibit concentration-dependent variation distinct from shear rheology response measured using shear rheometry or anticipated by blob models developed for relaxation of weakly perturbed chains. We show that the influence of molecular weight and chemistry can be evaluated a priori, using three macromolecular parameters: flexibility, extensibility and segmental dissymmetry for neutral polymers, and discuss additional influence of charge for polyelectrolytes. Finally, we characterize and analyze the pinch-off dynamics of multicomponent formulations to elucidate the influence of macromolecules on extensional rheology and processability of model food, cosmetics, coating, adhesive, and pharmaceutical formulations.