Comparison of model-free kinetic methods for modeling the cure kinetics of commercial phenol-formaldehyde resins

For many industrial processes it is important to model the cure kinetics of phenol-formaldehyde resoles. Yet the applicability of common model-free kinetic algorithms for the cure of phenolic resins is not known. In this study the ability of the Friedman, Vyazovkin and Kissinger-Akahira-Sunose (KAS) model-free-kinetics algorithms to model and predict the cure kinetics of commercial resoles is compared. The Friedman and Vyazovkin methods generate consistent activation energy dependences on conversion compared to the KAS method. In addition, the activation energy dependency on conversion is of higher amplitude with these two methods than with the KAS method. Hence, the Friedman and Vyazovkin methods are more adequate for revealing the cure steps of commercial PF resoles. Conversely, the KAS algorithm is easily amenable to dynamic cure predictions compared to the Friedman and Vyazovkin methods. Isothermal cure is equally well predicted with the three. As a result, the KAS algorithm is the method of choice for modeling and predicting the cure kinetics of commercial phenolic resoles under various temperature programs.