Waterborne bitumens

Depending on the application, relatively hard distillation bitumen, oxidation bitumen, or high-vacuum bitumen (hard bitumen) are used for physically drying bitumen paints. Waterborne bitumen paints and thick coatings (bitumen emulsions) are produced from moderately hard distillation bitumen. 

Waterborne bitumens may be anionic, cationic, or rarely nonionic emulsions, and are produced with the aid of emulsifiers and, if necessary, stabilizers conventionally used in the paint industry. The properties of bitumen paint (solutions and emulsions) (e.g., stability mechanical, weather, water, and chemical resistance corrosion protection properties) can be substantially improved by incorporating extenders. Suitable extenders include ground slate, ground limestone, chalk, talc, and mica (25 45 wt%, depending on extender type and required properties). The use of extenders... 

The NS 900 put into operation in 1970 was the very first vessel of designs 705 and 705K. In 1972 because of failure of NS primary circuit s auxiliary pipelines and impossibility of their repair, the NS was taken out of service after expiration of only 10% of fuel lifetime in the reactor. The RC was cut out of NS, and free cavities of the primary circuit were filled with preservative agents on furfurol basis. A bitumen-layer of about 1000 mm was laid over the whole surface of the upper deck of RC including the reactor upper head. Under such condition the RC is to be stored with nuclear fuel for long within the waterborne storage center. Some characteristics of NS, design 705, are demonstrated in Tables 3, 4 and 5. 

Emulsions are dispersions of one fluid into another. Both oil-in-water and water-in-oil emulsions are encountered. Foams are similar to emulsions, but the dispersed phase is a gas. Emulsions are everywhere some examples of products that are based on emulsions are salad dressings, mayonnaise, egg yolk, milk, margarine, cream, ice cream, waterborne paints and bitumen. Emulsions are generally not stable, so they need to be stabilized against coalescence. One can use surfactants for that, or polymers, such as proteins and polysaccharides, or particles. 

For applications such as swimming pools and water-purification tanks, for which chemical resistance is required, or where resistance to dynamic stress is needed, special epoxy resins are used. Blends of a waterborne synthetic emulsion with a cement compound are suitable for applications with lower requirements. In some cases, e.g. sewage-treatment plants, elastomer-modified bitumen mortars are still used. 

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