Hydroxyl value of Polyether polyol
Hydroxyl value is obtained from a sample of pyridine containing anhydride, which is first acetylized, of which excessive acetylized reagent then hydrolizes with water, and thus generated acetic acid is titrated with potassium hydroxide up to the endpoint.
The endpoint is determined by the inflexion point on titration curve.
Hydroxyl value of polyether polyol is calculated from titration volume.