Polymer Hydroxyl

Two Methods for the Determination of Polymer Hydroxyl Values Using 19F Benchtop NMR (2023)

The hydroxyl value (HOV) of a polymer, typically reported in mg KOH/g of polymer, is one of the key parameters typically reported in the technical data sheet (TDS) or certificate of analysis (CoA) of polymers containing hydroxyl functionalities. Several methods exist to determine the HOV of polymers, the most common of which is an acid-base titration. While conceptually simple, this approach is in fact elaborate, expensive, and wasteful from both a reagent and solvent perspective. In this application note, we present two quantitative benchtop nuclear magnetic resonance (qNMR) methods, which require very little solvent (deuterated solvents are not required) and small amounts of reagents. One of these methods is appropriate for polymers soluble in organic solvents, such as chloroform, while the other method is recommended for water-soluble polymers.