Polyurethane is a polymer that is highly versatile with a number of beneficial properties. It is durable, abrasion resistant, and is highly resilient. It can be used in a number of applications and comes in various forms. With all of these amazing benefits, you may wonder, is polyurethane waterproof? 

Is Polyurethane Waterproof?

To a certain degree, polyurethane is waterproof. However, there are several factors that make some types of polyurethane more or less absorbent than other materials. The physical properties and material can determine what level of absorption (or lack of absorption) occurs. In fact, a number of thermoset polyurethanes can have nearly zero water absorption compared to other materials.

The role of water absorption plays a critical role in the design of a product. You may wonder, what exactly is water absorption and how does it work? Water absorption is determined by the amount of water that penetrates a given material. Porous materials often have higher rates of water absorption due to the nature of the material. However, more solid materials have less water absorption. Some materials can even be waterproof, meaning that they do not absorb any water. 

Testing for Water Absorption

Values for water absorption are measured by the percentage of weight gain. This method takes roughly one week and involves comparing the wet weight to the dry weight. The water absorption depends on a variety of factors, including the type of polymer, what additives are in the polymer, the temperature, and the exposure time. There are standardized tests, most notably the ASTM-Standard D570 test, that offer consistent results when testing materials.

Polyurethane Types and Water Absorption

Polyurethane comes in a number of different forms. Common forms include solids and foam. These clearly display different levels of water absorption due their varying porosity. One of the major benefits of polyurethane is that it can be customized to repel water. This is unlike metals, rubber, plastics, and other natural materials which can be impacted by the customization. Oftentimes these materials can swell, oxidize, or corrode. However, polyurethane can be customized without the risk for these issues. This is why polyurethanes are commonly used in applications that are submerged in water or that experience high levels of humidity. Both of these scenarios require low water absorption to maintain the mechanical and physical properties of the application.

Using Polyurethane in Your Applications

Depending on your unique application, polyurethane is often a great material for projects that need materials with low water absorption. This is because materials such as metal, rubber, and thermoplastics can absorb water over time. This can be a serious issue in many applications. Product and application designers often need materials that are not impacted by water exposures. Issues such as stiffness, durometer, and dimensional changes cannot happen due to the impact they can have on the overall application or product. 

Using certain polyurethane, including engineered thermoset polyurethane, can meet the needs of various applications as the rate of water absorption can be customized. Using a polyurethane can ensure a low water absorption rate, reduced maintenance requirements, and increase the life of the application or component can be highly beneficial. Water absorption issues can have a serious impact on certain applications, which can unnecessarily cost you time and money.

Specialty Seals from Real Seal

Customizing your materials is necessary to ensure your application needs are met. If the application requires low water absorption, consider polyurethane. Polyurethane o-rings can meet the needs of your application due to the benefits that come with the material. They can be easily customized by the experts at Real Seal. They manufacture and distribute both seal products and mechanical component goods. Consider specialty seals from Real Seal for your project needs.