Comparative analysis of thermal degradation and curing reaction kinetics of traditional Phenolformaldehyde (PF) and sustainable Bio-Phenol Formaldehyde (BPF) resins

Abstract

This study investigates the thermal degradation kinetics and post-curing behavior of phenolformaldehyde (PF) and bio-phenol formaldehyde (BPF) resole resins using thermo gravimetric analysis (TGA). The analysis was conducted at four heating rates (5, 10, 15, and 20°C/min) over a temperature range of 25 to 700°C. The curing reaction kinetics of the resole resins were found to be approximately first-order, with activation energies of 132.2 kJ/mol and 131.6 kJ/mol for BPF resins with 25 wt% and 50 wt% bio-phenol replacement, respectively. These values are comparable to that of laboratory-synthesized pure PF resin (131.0 kJ/mol) but lower than that of commercial PF resin (138.1 kJ/mol). The thermal degradation kinetics revealed that the post-curing thermal stability of 25 and 50 wt% BPF resins is similar to that of commercial and laboratory-synthesized pure PF resin, whereas the 75 wt% BPF resin exhibits different thermal stability properties.