Polyurea coatings offer unique advantages that are superior to other types of protective coatings. We will be addressing several important questions when you are considering using polyurea coatings.

What is Polyurea?

Polyurea, an elastomer product made from step-growth polymerization that incorporates reactive isocyanate and artificial resin, is a result. Polyurea is made from an isocyanate and a resin mixture part by the step-growth method of polymerization.

There are many different formulas for resins and isocyanates that can produce the desired setup time, color, fire retarding, water resistance, and other attributes.

Crossbreed coatings are polyurea and polyurethane mixed in the right proportions. Crossbreed coatings provide details about the physical properties of pure Polyurea at lower prices.

What is the difference between Aliphatic Polyurea and Aromatic Polyurea?

Polyureas made from aromatic diisocyanates have a high ultraviolet (UV) light sensitivity. Sunlight direct exposure and synthetic UV light can cause deterioration in the Polyurea's properties and color makeovers like darkening or chalking. Aromatic Polyurea can be used as a base coat, but it is not recommended for top coats.

Polyureas made from aliphatic isocyanates are able to withstand sunlight exposure, and can be used under UV natural conditions. Because they have a glossy appearance, they are popular for outdoor applications. They can also be used at lower film densities (around 30 mils). They are still more expensive than aromatic polyureas due to the need for facility handling.

What are the Unique Traits Of Polyurea?

Because of Polyurea's unique physical properties, stability and commercialization, no coating system can successfully alter it in any way. Its surface preparation specifications are very strict.

Polyurea protects steel, concrete and wooden surfaces from rust and abrasion. It can help protect concrete structures that are deteriorating and assist in rehabilitation and maintenance of canals. It can withstand chemicals, oils and salts used in commercial and industrial flooring applications. It protects watercraft and other vessels from damage by protecting them against splitting and deterioration.

Polyurea coatings have the following advantages:

Setup time is quick

Excellent scratch and abrasion resistance

Extremely strong resistance to environmental and weather conditions

Excellent for commercial or residential properties that need to be extended

It can also be used in extreme temperatures

You can finely regulate the coating density

Highly effective bonding of cement, concrete, wood and metals on well-prepared surfaces

Superior chemical resistance

Low viscosity is a useful tool

It can be made with a high tensile force

What is Polyurea's comparison to other Epoxies.

Polyurea has a significantly higher wetness resistance than epoxy coatings. It also resists UV (for aliphatic coatings), abrasion, chemical resistance and temperature resistance. Polyurea also has a faster cure time.

Polyurea is a superior alternative to polyurethane in terms of toughness, chemical endurance and dampness resistance.

What are some examples of Polyurea Coatings that can be used?

Polyurea coatings have many benefits, including the following:

Automotive market and material management

For more than 30 years, the automotive industry has used polyurea coatings. Because of its impact resistance and other mechanical properties, the coating is very popular.

Polyurea provides abrasion protection in mining and building equipment. It can also be used for lining dumps that are used for abrasive materials such as coal or metal ores. It protects the conveyors as well as waves of conveyor systems moving abrasive stones, metal ores, and abrasive coal.

It can also be used for bed linings, big industrial lorries, and product handling trucks.

Safety and defense markets

Polyurea coatings are able to be used in protection and protection sectors due to their proven effect resistance, ability to absorb explosive power, durability and quick setting characteristics.

The use of Polyurea in the ballistic missile defense system has been well documented. Polyurea is a coating for military devices that can adapt and broaden to suit the changing ambient temperature and provide a moisture seal. The coatings are guaranteed to be free from marks, dents and abrasion damage, while still retaining a glossy appearance. Spray coating polyurea on truck bed liner can reduce vibration and increase security. Polyurea can be used to coat structures of armed forces in order to reduce damage from bomb blasts.

Concrete bridges and steel surfaces

Polyurea is used as a first and second coating. It has a fast healing capability, influence resistance, elongation and high tensile strength. Polyurea's molecular chain (the framework) makes it an extremely durable elastomer. This is why it's so versatile in construction and other areas.

Polyurea coatings are a way to prevent concrete structures from collapsing by properly repairing the concrete framework. They also provide a protective seal around fractured and deteriorating concrete.

What are the limitations of polyurea coatings?

Polyurea coatings have their limitations, but also unique aspects.

The coating is very responsive and quickly cures, so if the coating setup is not done properly, it can cause poor attachment to the substrate. Before coatings are applied, formulators must ensure that the entire surface area is moistened. This is a very difficult situation.

The UV radiation can cause shade adjustments or liquid chalking in the case of aromatic polyurea coatings. UV radiation can negatively affect the appearance of these coatings. An aliphatic polyurea is recommended for applications that have a high aesthetic appeal.

High-pressure and high heat spray applications require specialized, innovative spray equipment. This task requires specialists who are trained in this area.

For success, formulation, primer option and thorough surface preparation are essential.

To learn more about Polyurea, or to become a certified ArmorThane polyurea application specialist, call or visit this website to ask questions.

The Competition: Polyurea vs. Other Coatings

Many people believe in traditional protective coatings and do not wish to change anything up. There is nothing wrong with sticking with what you know works, however, if you can use a more suitable product for a lower price, why wouldn't you try something new?

The graph shows that polyurea is superior to traditional coatings in many aspects.

 The above side-by-side comparison chart shows how polyurea technology compares to epoxy and polyurethane coatings. As you can see, this highlights the advantages of polyurea over the other options.

It is important to understand how polyurea works compared to epoxy and polyurethane. Both traditional systems can take several days to cure. Polyurethane and epoxy are more sensitive to temperature and moisture conditions. Polyurea is a much more straightforward choice because it doesn't have these same issues.

Maintenance costs are another important aspect to remember. Polyurea is easy to maintain. All you need is to wash it off and remove any buildup or grime. It's not necessary, but it makes the product look better.

Polyurethane and epoxy will require maintenance. This may mean that there might be downtime.

Repairing cracks with epoxies will likely be the biggest problem. This can be very difficult.

Polyurethanes will need to be re-coated at least every 4-7 years depending on several factors. The main reason for this is the weak bond to the substrate.

What are the benefits of polyurea?

It takes less time to install and more time to cure.

Polyurea is the clear winner in terms of installation & cure time. We can apply the coating in a matter of hours and then do touch-ups and cut-ins within the same day. You can also get back to work in less time with this coating option than you would with other options.

Less important are installation conditions

Epoxy coatings require that the temperature of the product be maintained at 50 degrees F throughout the installation and cure. Polyurethane coatings have a wider temperature range, so multiple applications may be necessary to achieve the desired thickness.

Polyurea can, however, be installed at temperatures that you don't want to be there for long periods of time. This makes polyurea ideal for installation in cold and hot conditions. Polyurea is a highly buildable coating that requires fewer passes to attain the desired thickness.

Finally, maintenance can be eliminated.

Are there ongoing maintenance costs? Yes, with epoxy and polyurethane. They may need a complete recoat (polyurethane won't). Polyurea will be close to the zero maintenance cost mark, which makes it more attractive in the long term.

Polyurea may have a nominally higher initial investment, but it is more affordable than other coatings when you consider the extended downtime required for maintenance and repairs with epoxies or polyurethanes.

Flexibility and long-term success

It's easy to believe that concrete will remain stable when a protective coating is applied to it. Concrete contracts over time as it cures, so this is not always true. Concrete is extremely elastic and can cause damage to structural compositions. Any protective coating must be able to accommodate this kind of movement.

Polyurea can handle most structural displacements but is more flexible than epoxy or polyurethane. Concrete can often fail internally due to its high bond strength. A polyurea coating may be the best option to prolong the useful life of your infrastructure.

1. Balance the chemical mixture: Spray foam must be applied according to the manufacturer's instructions. Does your foam stick to the substrate? Does it smell fishy? These are signs that your ratio is not correct. You will need to apply another application and waste additional material. The foam is resin-rich and the fishy smell can be explained by a decrease of the "A" side.

2. Watch your internal drum temperature: Material should only be used at the manufacturer's recommended temperature. It is equally important to keep stored material within the material temperature storage range. Material stored at the correct temperature will prevent it from getting too hot and make it ready for use.

3. Reduce oxygen levels: Air can either be your friend or enemy. It helps cure the material by allowing it to cool. The air helps to cure the material; however, too much air can settle in the drum and cause moisture to build up. Desiccant Dryers can be an economical way to prevent moisture buildup.

4. Do not store too much: Have you heard of Newton's First Law, which states that you should not keep your material for too long? Your material is the same. Spray quality drops if it is left to sit for too long. If your material has been sitting for too long, chances are it is at the wrong temperature. It is best to use material as soon as possible. Even if the material was designed for cold weather, it will still be suitable for use in summer.

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.

Moisture causes iso crystals to form, blocking the drum, hose, and other components, ultimately destroying polyurea material and equipment. Stopping iso crystals before they form means preventing any moisture from settling into the drum. 

The way you can prevent this is by attaching a desiccant air dryer to the drums. This device removes moisture from the air during pumping. It stops the moisture from causing iso crystals, ultimately clogging the filters and prematurely curing the material while it’s still inside the hoses.

The “A” component, while in the drum, will react with atoms in the air resulting in the formation of crystal-like skin structures. The “A” material should be sealed properly to limit the potential of these formations that, if allowed to form, will contaminate the liquid. Contamination may make the liquid impossible to process, requiring disposal and wasting of the product. Once the drum is opened, the air needed to replace the “A” material being removed should be dry. This is achieved by either low-pressure nitrogen being let in the drum as the material is displaced or filtered through a desiccant dryer.

Pros & Cons of Desiccant Air Dryers