| 摘要 |
<p>A pyridine-free esterification reagent for anhydride method to determine the hydroxyl number of polyols is provided. The reagent includes an anhydride, an oxometallic complex having a formula of MO m L n , and a neutral or slightly acidic solvent, wherein M includes transition metals of IVB, VB, or VIB group, L includes (OTf), X,
and m and n are an integer greater than or equal to 1, wherein X is halogen, and R, R', R'', and R''', independently, are alkyl, aryl, or heterocyclic groups containing nitrogen, oxygen, phosphorus, or sulfur heteroatoms. The invention also provides a method to determine the hydroxyl number of polyols.</p> |
