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Surfactants for Bituminous Emulsions
Surfactants for the production of bituminous emulsions with high mechanical and storage properties, also ideal for polymer-modified bitumens.
The emulsions are a dispersion of a liquid in the form of very small droplets (dispersed phase) in another immiscible liquid (continuous phase). Bitumen emulsions are of the “oil in water” type, where the continuous phase is water and the dispersed phase is bitumen. Observed under a microscope, the bituminous emulsions appear as spherical particles with a variable diameter from 0.1 to 10 microns. Bituminous emulsions contain from 50 to 70% of bitumen and the rest is water, they are liquid. Bitumen and water can form an emulsion if mixed, but immediately separate when the mixing ends, therefore an emulsion must contain a third component to be stable: the emulsifier, which delays or avoids the separation of the phases. The emulsions consist of molecules that have both a lipophilic and a hydrophilic part. At the bitumen / water interface the emulsifier orientates itself with the hydrophilic part in the water phase and with the lipophilic part in the bitumen phase.