Hydroxyl Number in Polyols (OH#) #3013

The use of polymeric polyols is commonplace in the manufacturing of polyurethanes and other specialty polymers. The hydroxyl number (OH#) is a measure of the concentration of the hydroxyl groups on the polyol. This is an important parameter to monitor and control during polyol production. The laboratory method that is commonplace for hydroxyl number determination is both time consuming and involves the use of hazardous materials. This note will discuss the use of Guided Wave hardware and software tools for the measurement of hydroxyl number in polyols using fiber optic-based, Near-Infrared (NIR) spectroscopy. NIR can be applied in real time directly in process or as a laboratory procedure. In either case NIR is a time and money saving alternative to traditional methods. NIR also offers the benefit of increased safety over traditional methods. For well established process measurements, a Guided Wave ClearView® db multi-wavelength photometer can be used to achieve similar results.