Urethane formulations can be designed to survive a wide range of operating environments. Tough and durable, urethane can stand up to some of the most demanding environments on the planet.
- Polyurethane is very resistant to extreme conditions, and in some cases can withstand temperature ranges from -50 to 300 degrees Fahrenheit.
- Polyurethane can be used in wet or dry conditions, and can be specially formulated to withstand relative humidity ranges from 0 to 100%.
- Upon exposure to UV radiation, polyurethane will experience a shift in color and begin to yellow, however this is primarily an aesthetic change; there is typically no adverse effects to the product’s physical properties.
Limitations
High Temperature Service
Due to their plastic/rubberlike nature, polyurethane physical properties tend to fall off at elevated temperatures. Generally speaking, urethanes are not useful materials under heavy service loads at temperatures above approximately 220-225°F (105-107 °C).
Moist, Hot Environments
Another limitation is that ester polyurethanes are subject to hydrolysis when in the presence of moisture, humidity and elevated temperatures. The combination of these factors will create a major problem for ester polyurethanes. Ether formulations are designed to withstand hydrolytic attack. Below 125°F, most polyurethane can withstand continual contact with water for many years. Between these two extremes, there is a wide range of temperature and moisture conditions under which polyurethanes may or may not be suitable for use. It is best to contact your Argonics representative to help with the proper material selection.
Chemical Environments
There are certain chemical environments that are unsuitable for polyurethanes. Very strong acids and bases generally are detrimental, as are certain solvents (specifically the aromatic solvents such as toluene or ketones such as MEK or acetone) and esters such as ethyl acetate. There are many chemicals, on the other hand, which urethanes resist very well and are suited for in-contact service. These include many oils and petroleum-based materials. View the Polyurethane Chemical, Oil and Solvent Resistance Guide for more information.