Modeling of resole type phenolic resin formation

Abstract

A kinetic model was developed to predict the behavior of resole type phenolic resin formation under NaOH-catalyzed condition in batch reactor. The proposed model was developed by reducing the ionization equilibrium equation for each component of Zavitsas’ model and adding an equation for calculating initial water concentration. The proposed model was compared with two models : a simple model in which equilibrium was not considered in the system and Zavitsas’ model where phenate ion and formaldehyde equilibrium were included. Parameters in these three models were estimated and compared with experimental data from literatures in the range of 30 to 90 oC and initial phenol concentration of 0.5 to 5.375 mole/l by Simplex method. The proposed model was found to be in best agreement in comparing with the experimental data. Rate constants in concentrated systems were found to be higher than those in dilute systems due to the influence of solvent quantity on rate constants. Two relationships between rate constant and initial water concentration were studied : linear relationship and Born ’s relationship. The results show that the proposed model with the linear relationship of rate constants and initial water concentration was the best model to predict resole resin formation.