We have written in this space about different performance polyols used to achieve the desired performance of elastomers in various applications. In addition to the disocianate type, polyols offer formulators an ability to achieve a variety of processing and performance advantages.
In this article, we are bringing it all together through a direct comparison of the key attributes of each polyol family, for the purpose of helping users with a quick guide for polyol selection when formulating coatings, adhesives, sealants, and elastomers.
A very important step for proper polyol selection is to determine the key properties for a given application and the environment in which the parts are required to perform. Urethane parts, for example, are used for their toughness, versatility, and durability. It's critically important to ensure that the initial properties will not significantly deteriorate over time, due to adverse environmental exposure. Selecting the best polyol for a specific formula can be the difference between making a high-quality product or one that's low performance.
Common examples of negative impacts the environment can have on urethane parts, which can accelerate their deterioration, include hydrolysis of ester-based urethane in hot and humid conditions, as well as the loss of properties that ether-based materials normally exhibit when exposed to either a hot environment or to direct sunlight.
A good understanding of the inherent characteristics of each polyol chemistry is key for making a proper material selection for any particular application and avoid loss of modulus, tensile, and tear strength due to environmental exposure.
Next, we'll cover the basic chemistry of each polyol group, the key attributes of their physical properties, their environmental/chemical resistance, and the typical applications we see for these types of polyols.