SIMULTANEOUS DETERMINATION OF PHENOL, FORMALDEHYDE AND BENZYL ALCOHOLIN MANNICH PRODUCTS USED AS CURING AGENTS FOR EPOXY-RESINS BY DIRECT GAS CHROMATOGRAPHIC-FID ANALYSIS

Of the many agents suitable for curing epoxy resins at room temperatur e. those with a Mannich base product as the main component are frequen tly selected because of their relatively low viscosity and particularl y good curing properties. However, most commercially available Mannich base curing agents contain free phenol, which accelerates the epoxy-a mine reaction but is subject to legal limits for toxicological reasons . We describe here a direct gas-chromatographic-FID method for the sim ultaneous determination of residual levels of phenol, formaldehyde and benzyl alcohol in Mannich formulations prepared for use as curing age nts for epoxy resins. Knowledge of these levels allows the conditions of synthesis of such formulations to be optimized so that emission of these raw materials is minimized. The analytical method is sensitive a nd linear over a wide range of concentrations.