Polyurea: A Review
Polyurea has drawn the attention of builders and engineers as a modern building material due to its unique structure, unique properties, and relatively easy application even in hard-to-reach places. A wide range of superior properties such as durability and high resistance against atmospheric, chemical, and biological factors have made this polymer an exquisite option for the construction industry. The ability to support the building materials and structures coupled with excellent resistance against corrosion and abrasion has dramatically increased the popularity of polyurea as a protective coating in the construction industry. In these industries, sealing and insulating the different floors and surfaces have also been considered using polyurea coating.
Polyurea coating technology is a green technology without pollution and toxicity to the environment, which is an essential advantage over many competing technologies in the construction industry. The use of polyurea composite systems to optimize various properties such as mechanical and thermal properties in addition to lowering the costs and economic burden is increasing. In the present paper, multiple applications of polyurea-based materials in the construction industry are discussed.
A polyurea is a polymer based on the reaction of an isocyanate with a polyamine. It is mixed at a high temperature (around 80°C) to initiate rapid polymerization. The resulting polymer is highly elastomeric –that is, it has a high capacity to deform (stretch) and recover. Coatings based on polyurea elastomer also exhibit extraordinary
toughness and resistance to impact, tear, and abrasion. Furthermore, polyurea polymers cure at lower temperatures and operate at much greater extremes of temperature than other polymers. Polyurea elastomer coatings are 100% solids, contain no volatile organic components (zero VOC), and are therefore virtually
odorless. They cure within minutes, so flooring and equipment can undergo maintenance with minimal disruption. This combination of properties offers unique opportunities for true polyurea elastomer coatings in the protective coatings industry.
WHAT IS A POLYUREA HYBRID?
A true polyurea elastomer is the product of the reaction of a polyisocyanate component and an amine-terminated resin (polyamine). Polyurethane is the product of the reaction of a poly-isocyanate
component and a polyol. Polyurethanes have significantly different properties from polyurea
elastomers. Polyurethane is generally hard and of low flexibility and therefore an ideal finish coat as part of a protective coating system over steelwork, car bodies and other rigid, dimensionally stable substrates not normally exposed to high mechanical impact. A polyurea hybrid is the product of the reaction between an
isocyanate and a mixture of polyol and polyamine reactants. The resultant hybrid behaves as a blend of polyurea and polyurethane and thus its properties are a compromise between the two. A polyurea hybrid, therefore, does not have the strength, flexibility, elasticity or recovery characteristics nor the temperature tolerance of
a true polyurea elastomer.