Simultanbestimmung von Hydroxyl- und Epoxidgruppen in Epoxidharzen

Abstract

A simultaneous titrimetric determination of the epoxy- and hydroxyl group in epoxyresins is given. After reaction of the resin with acetylbromide and hydrolysis of the unreacted acetylation agent the residual hydrobromic acid and acetic acid are titrated simultaneously. The acetylation is carried out in N,N-dimethylacetamide as an excellent solvent even for longer chained resins. The method shows a good reproducibility for hydroxyl aequivalents down to about 0,3 equivalents per kilogram.