Friday, July 2, 2021

History Of The Industry Adoption of Polyurea Coating Systems



We have made great strides in understanding the benefits and drawbacks of the chemistry involved with spray coating technology for polyurea over the past decade.

Downtime can be costly in today's industrial environment. For example, the oil and gas industry uses fast-set spray systems to create secondary containment for well sites. Owners may have to pay more than $100,000 per hour for downtime when coating projects are being completed on such jobs. These secondary containment projects are vital because the U.S. Environmental Protection Agency is closely monitoring these areas.

Polyurea technology has seen improvements in recent years. These include poor adhesion and limited availability of raw materials. For assistance in choosing coatings, contact ArmorThane today, and they will be happy to help you find a product to fit your needs.


Slowing the Gel Time

The most significant change has been the increase in the number of raw materials. There was no doubt that polyureas had a fast reaction time when they were first created. With secondary diamines now available, chemists can "tune" the system's reactivity using gel times.

The addition of high-quality 2,4 MDI prepolymers is a less common method to slow down the pure polyurea system. Formulators can reduce the gel time of pure polyurea systems using the steric hindrance of the 2,4 position at the free NCO. This often results in higher substrate adhesion as well as improved physical properties.

Pure polyureas can now be slowed down by incorporating these new raw materials to avoid adhesion problems caused by "wetting."


Famous Bridge Failures in Retrospect

Early-generation polyureas caused many coating problems. It has taken a lot of effort to learn more about surface preparation and create a coating specification. 


Many articles have been written about the famous San Mateo Bridge built in San Francisco Bay Area. I've followed the history of the job and spoken to people involved with the failure analysis. This job was very successful, it should be said.

Fast set, unlimited film build, and zero volatile organic chemicals (VOCs) were all attractive features that attracted many inexperienced suppliers to the polyurea industry. This, in turn, led to a new frontier for coating specifiers.

This famous failure resulted from substrate preparation that was incorrectly specified and how specifications were written to address changes in job conditions every day.


Standards and Equipment Advancements

The efforts of groups such as the Polyurea Development Association and SSPC standards and specifications have been developed to provide proper surface preparation for the polyurea system. The proper methods for installing polyurea coatings are now better known in the industry.

While formulators and applicators are often blamed for the early failures of polyurea jobs, equipment is also important. Applicators often had to work outside of the formulators' parameters due to poor heating control and limited pressure buildup in early machines.


The application process has become easier and more precise thanks to new pumping systems. Manufacturers have improved the quality control features of equipment to alert the user when there is a problem with the mix ratio. This feature was not possible in the past.


The Future of Polyureas

The failure rate of polyureas has decreased due to improvements in surface preparation, spray equipment, and raw materials. This is a good sign for the future of polyureas. The industry is learning the "do's" and "don'ts" in choosing the right system and chemical for each job. This is a time when the specifying community is putting their trust back into polyureas.

Pure polyurea can be a valuable addition to many industrial applications if it is correctly formulated and specified. Polyurea chemistry can reduce unwanted reactions to the environment and provide a high-value solution in many corrosion and waterproofing situations.

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