Over the last 15 or so years a new technology has been steadily growing in recognition throughout various industries. This technology is an advancement of polymer chemistry based on an earlier chemical family known as polyurethane. The newer technology, known as “polyurea”, takes the form of plural component elastomer systems and has been formulated to provide casting, coating and caulking products that exhibit superior characteristics. Plural component elastomer systems have been known for decades. In fact the reactions forming the basis of polymers were discovered about 1850. Actual polymers were formed as early as 1937 and during the 1950’s and 1960’s urethane development was one of the focal points of new discoveries. The use of urethanes as elastomer coatings came to significance during the 70’s and has continued to command a large share of the coating and sealant market. Urethane technology generally utilizes a catalyst in the systems to promote proper curing. Typical problems encountered with catalyzing systems are moisture and temperature sensitivity. Additionally, catalysts may become a deteriorating element in certain systems. These problems often plague urethane systems. Polyurea does not use a catalytic process, therefore once the chemical reaction has occurred the resulting product is quite inert. However, the extremely reactive nature of polyurea components has formed a general barrier to its use.

Extremely rapid reactions present problems in proper mixing and application. In the early 80’s some of these problems began to be addressed using sophisticated plural component high-pressure equipment. These uses were in RIM (reaction injection molding) and spray application. (The polyurea systems are in wide use in the automotive industry where bumpers, cowlings, side panels, dashboards and other parts are routinely made from polyurea). The polyurea systems are fast systems. They are two component, solvent free and 100% solid. Moisture during the application does not significantly influence the curing performance of the polymer. Likewise, temperature does not present a problem either. As mentioned before, the rapid reaction times presented a barrier to use of the systems for any type of casting, pouring or mobile manual applications. Thus, while the end polymer products exhibited much better performance characteristics than typical polyurethanes, the installation issues caused by the rapid reactions allowed for use of polyurea systems in only a narrow range of situations.

Starting in the mid-80’s Texaco Chemical Company began devoting significant resources to the development of polyurea systems as a complimentary use for their patented raw material known as Jeffamine. Significant strides were made in developing spray formulations of polyurea with set times of 1.5 - 3.0 seconds. Development of industrial uses necessitated improvements in processing equipment. Gusmer Corporation, a leading provider of impingement processing equipment, worked closely with Texaco in producing innovative equipment for delivery of the polyurea systems

Caulking and Sealing Products

During the period from about 1990 to 1995 a handful of companies entered the polyurea formulation business. A variety of target markets were identified and several system manufacturers began efforts at producing slower versions of the polyurea systems with a focus on sealant and caulking products. The greatly improved performance of the polyurea systems provided the impetus for pushing forward with product development. Steady increases in the use of the polyurea joint filling and sealing products have been made over the last several years.

A general consensus has been building among knowledgeable designers of floor systems that the polyurea joint filling products exhibit the optimum characteristics for long-term performance under heavy use conditions. Several new vendors of polyurea have entered the market, some adding the technology to long standing product lines. Refinements in the equipment for delivery of the systems have been made and a greater number of experienced contractors make specification of polyurea systems a viable alternative.

A detailed analysis of the polyurea technology unmistakably points in the direction of replacement of many urethane systems. The superior characteristics of the polyurea must inevitably be recognized. The higher costs of polyurea will present certain market barriers until evaluated on the basis of performance. The largest challenge in developing polyurea products for caulking purposes has been to maintain the performance characteristics while slowing the reaction times enough to allow for traditional installation. The rapid curing features are a significant selling point, especially where facility shutdown is an issue. Obtaining pot life of up to 5 minutes is pushing the extremes of the slow down potential for these products if they are to maintain the polyurea characteristics and performance.

Polyurea Coating Products

The initial uses of polyurea chemistry were in fixed place impingement molding facilities. The technical advantages of the systems require high-pressure spray application. Only recently have the equipment designs necessary to mobilize the coating potential become commercially. At the end of 1995 the market had only a few mobile coating equipment packages capable of applying the polyurea systems. Delivery equipment units are somewhat expensive and require technical training to operate and maintain. Nonetheless, protective and specialty coatings based on polyurea represent significant advantages over other coating systems.

The polyurea chemistry is quite resistant to a broad range of corrosives, and cured products exhibit excellent adhesion and abrasion qualities. Perhaps the most significant advantage, certainly the most evident, is the incredibly fast cure time of the systems. Rarely can a protective coating be installed and used within the same 24-hour period. The extremely fast curing aspect of polyurea systems forces a close examination for any application which is constrained by time and temperature.

As we move into the 21^st century the uses of polyurea systems continues to expand. The market has moved from negligible to perhaps $100M in annual sales of coating products. Use as waterproofing and containment membranes is the leading current use but as the technology becomes more widely understood and the universe of technically proficient applicators increases a much broader industrial market is beginning to open. Longer life cycles for infrastructure demands that protective coatings be evaluated as viable alternatives for substrate replacement. The unique physical structure of polyurea membranes places this technology in the forefront for life cycle economic analysis. The compatibility of these coating systems with various substrate materials such as steel, concrete, wood and other synthesized materials further broadens the horizon of uses. Every industry expectation is for geometric growth in the use of polyurea as a coating and sealing elastomer.