Safelite Autoglass Practice Test

When a diisocyanate reacts with hydroxyl groups, urethane linkages form, creating polyurethane polymers. The term urethane (often used to refer to the polymer class itself) captures this specific type of bonding resulting from the reaction between isocyanate groups and alcohols. Polyester, epoxy, and silicone involve different bonding chemistries—esters from acids and diols, epoxy rings from epoxides, and siloxane networks from silicon-oxygen bonds—so they don’t arise from diisocyanate–hydroxyl reactions.