Polyurea is a kind of synthetic foam that is derived by the process of step-growth polymerization from an aliphatic sap component and an isocyanic acid component during step-growth. The polyurea can be aliphatic or aromatic in composition. This polyurea is used as an insulator in many applications. It is also used as a lubricant and to decrease friction in certain machinery parts that need lubrication.
Polyureas come in two forms – open cell and closed cell. In the open cell polyurea, the isocyanates are present in the solution while in the closed cell, the isocyanates are enclosed within a sheath. The closed cell polyurea has high absorption and re-emission characteristics. These characteristics make the polyurea an excellent insulator in various industry types including Pharmaceuticals/IGM, Pharmaceutical, Biotechnological and Nanotechnology industries. It is also used as an antimicrobial, a deodorizer, a flame retardant, a sound absorbent and as a moisture barrier.
Polyurea foams are applied on concrete surface with the help of a high pressure spray. It makes the concrete more rigid and durable than other kinds of concrete coatings. It also helps to reduce corrosion on concrete surfaces. Polyurea has good fire retardancy properties. Due to its high absorption and re-emission characteristics, this polyurea develops high impact resistance. This property makes it ideal for use on concrete slabs that experience high traffic.
Polyurea products provide additional layer of protection to concrete against chemical resistance. Some common chemicals that have high impact resistance potential include hydrochloric acid (HCL), diesel engine oil, phenol carbolic acid (PCA), ferricyanide and urethane. The multi-layer protection provided by polyurea makes it highly beneficial. As it provides significant tensile strength, it can support heavy loads without causing any stress cracking.
Polyurea surface preparation involves application of a thin layer of polyurea coating over the exterior concrete. This coating imparts excellent physical properties to polyurea. The thickness of this coating increases depending upon the extent of polyurea application. After the polyurea coating is applied, it begins to form a smooth surface which inhibits the growth of microorganisms, thus protecting the concrete from external sources like liquids and dust.
In addition to its physical properties, polyurea coatings offer several advantages over alternative polyurea options. The polyurea material is highly resistant to fire and therefore, it is suitable for use on combustible substances. Apart from being highly durable, polyurea also provides high levels of impact resistance. With these advantages, polyurea has emerged as the most effective choice for applications where complete protection of concrete is required, such as for use in high-rise steel buildings, in the reinforced concrete section of the highway or in the foundation of the building, where additional strength is required.