New Framework to Model Both Polymerization Kinetics and Polymer Final Properties via Rheological Structural Modeling

Numerous industrial processes present irreversible rheological time-dependent kinetics such as gelation, hydration of cement pastes, solvent evaporation in adhesive film forming, curing kinetics in polymerization process, etc. The rheological modeling of this kind of system is in its full development. In the present paper, we propose to use a structural model to describe the polymerization kinetics of acrylic acid in an aqueous solution with sodium persulfate as an initiator. The chain growth of the polymer is described within the model in terms of a structural parameter λ, similar to a monomer conversion degree, and the shear-thinning behavior of the polymer is captured by a power-law. The rheophyscial model not only describes the transient polymerization kinetics as well as the rheochemical models but also predicts successfully the steady state rheological properties of the final polymer. Furthermore, it involves fewer equations than the rheochemical approach, so that it may easily be implemented in commercial CFD software to simulate the flow of reactive fluids in industrial geometries such as agitated tanks, extrusion dies, etc.