Cationic Bitumen Emulsion Description
The term Cationic Bitumen Emulsion is derived from the migration of particles of bitumen under an electric field also. The droplets migrate toward the cathode (negative electrode), and hence the emulsion is called cationic. The cationic emulsifying agent functions similarly to the anionic; the negative portion of the head floats around in the water leaving a positively charged head. This imparts a positive charge to all the droplets.
Since positives repel each other, all the droplets repel each other and remain as distinct bitumen drops in suspension. A typical cationic emulsifying agent is shown below along with a diagram showing the orientation of the agent at the bitumen-water interface and the positive charge imparted to each drop. A stable dispersion of bitumen in water in the continuous phase.
The bitumen globules are positively charged due to the NH3 + group cover which is formed around bitumen droplets and provide stability for emulsion by electrostatic repulsion. These bitumen droplets have an affinity with the negatively charged aggregate, which is usually available in India. Dispersion is obtained by processing bitumen & water-based solution under controlled conditions through a colloidal mill having a high-speed rotor in the presence of scientifically selected surfactants/emulsifier. Selection of emulsifier & its quality is significant for emulsion stability, it’s breaking & curing when applied over aggregates.
The term cationic is derived from the migration of particles of bitumen under an electric field also. The droplets migrate toward the cathode (negative electrode), and hence the emulsion is called cationic. The cationic emulsifying agent functions similarly to the anionic; the negative portion of the head floats around in the water leaving a positively charged head.
This imparts a positive charge to all the droplets. Since positives repel each other, all the droplets repel each other and remain as distinct bitumen drops in suspension. A typical cationic emulsifying agent is shown below showing the orientation of the agent at the bitumen-water interface and the positive charge imparted to each drop. Chemical surface-active agents, serving as emulsifiers, are classified by the electrochemical charge that is attained when they dissociate in a water solution.
In the case of cationic emulsions, the chemical charge is positive. The chemical type and quantity of surface-active agents used in the manufacturing process govern the process in which the resulting asphalt emulsion can be used. If you are more interested in product information or need to place an order contact or inquire about our Sales team.
Advantages of Cationic Asphalt Emulsion
Bitumen Emulsion does not need petroleum solvents for liquefaction, such as Cutback, nor does it have to be heated like regular bitumen, thereby saving on imported firewood or petroleum oil. As no heating is involved, toxic fumes (e.g., hydrocarbons) normally emitted from heated bitumen or Cutbacks are avoided. Furthermore, the cold application of Bitumen Emulsion ensures the safety of workers and qualifies it as a friendly product to use. Also, as it is applied cold, work proceeds much more quickly.
Application of Cationic Asphalt
Emulsions were first developed in the early 1900s. It was not until the 1920s however, that emulsions, as we know them today came to the fore due to its ecofriendly behavior & other advantages, the use of Cationic Bitumen Emulsion has had a steady rise in demand worldwide. Cationic Bitumen Emulsion has been recommended to use in several applications of Road Work like Tack Coat, Prime Coat, Surface Dressing work, 20 mm Premix Carpet, Sealing of cracks with fog seal, slurry seal, micro-surfacing, etc.
