Thermal Behaviour of Phenol-Formaldehyde (PF) Compounds

The self-condensation reactions of 2- and 4-mono-methylol phenols (2-MMP and 4-MMP), in the presence of varying concentrations of NaOH, have been studied by differential scanning calorimetry (DSC). The reaction exotherms were analysed to derive the activation energy, E_a, and the heat of reaction, H_T, for the condensation reactions. In the case of 2-MMP an increase in NaOH:2-MMP molar ratio caused an increased in E_a and a decrease in H_T up to a molar ratio of 0.6:1. However, for 4-MMP, an increase in NaOH concentration caused an increase in E_a up to a molar ratio of 0.3:1 beyond which there appeared to be no further effect. The presence of NaOH had no effect on H_T for this compound. The results suggest that in the range of NaOH concentration used the effect of NaOH was substantially greater on 2-MMP compared to 4-MMP. This revised version was published online in August 2006 with corrections to the Cover Date.