Both kraft lignin phenol-formaldehyde (KLPF) and phenol-formaldehyde (PF) resins were synthesized and the curing kinetics of the resins was determined using thermal analysis data. The kinetic parameters were predicted using two popular model-free kinetic (MFK) methods: the advanced form of the Vyazovkin method and the Kissinger-Akahira-Sunose method. From the experimental and predicted values, the rate of kraft lignin phenol-formaldehyde curing was less compared to the phenol-formaldehyde resin. To increase the cure rate different cure additives were tried. Among these, only potassium carbonate (KC) showed a positive effect: An increase in additive concentration to 4% reduced the curing time to almost 50% as compared to pure KLPF resin at 160 degrees C. Comparison of the predicted values from MFK calculations with isothermal experimental data showed that both MFK approaches were suitable to predict the curing characteristics. (C) Koninklijke Brill NV, Leiden, 2010