| Abstract: | Resoles, the complex, heat-sensitive product mixture from the alkali-catalyzed reactions of phenol with formaldehyde were investigated by gel-permeation chromatography (GPC). The low molecular weight species of these resins which consisted of mono-and dinuclear methylol phenols were resolved into multiple peaks. Model compounds were used to identify the peaks of the specific methylol phenols or methylene etherbridged diphenols. Differences in the refractive index of individual species restricted the quantitative analysis of low molecular weight components in the resole. The effects of sodium and barium hydroxides and hexamethylene-tetramine as catalysts, reaction temperature, and time on the total composition of a resole are demonstrated with the gel-permeation chromatographic spectrum and with the aid of NMR. Formation of a “secondary” resole by methylolation of the bisphenol of formaldehyde was also monitored by GPC. |
