Bitumen Emulsion Destabilization Kinetics: Importance of the Crystallized Wax Content.

We study the kinetics of bitumen emulsion destabilization after the addition of sodium hydroxide (NaOH) using macroscopic observations and rheology. Destabilization occurs in a two-step process: first, emulsion flocculates, forming a percolated network of contacting drops, and then coalescence provokes the irreversible connection of bitumen drops, leading to a bitumen continuous network that further relaxes the shape. We show that the destabilization kinetics exhibits a rheological easily identifiable signature allowing reproducible and accurate measurement of the connection/coalescence time t (which corresponds to the time, determined by rheology, required to form the network made of drops connected by nonrelaxed coalescence).