Polyols

While isocyanates play a decisive role in polyurethane production, polyols (substances with hydroxyl groups) significantly influence the final properties of polyurethanes. It can be said that the physical, chemical, and mechanical properties of polyurethanes are directly dependent on the chemical structure of the polyols used in their production. Molecular weight, functionality (number of functional groups), and the nature of the polyol affect polyurethane properties. The most common polyols used in polyurethane production are polyether and polyester polyols, followed by amine-terminated polyether polyols and, to a lesser extent, polycaprolactone polyols. Initially, only polyester polyols were available in the polyurethane industry due to the superior properties of polyurethanes produced with them, such as better heat resistance and higher solvent resistance compared to polyether polyurethanes.