Thermal degradation characteristics of phenol–formaldehyde resins derived from beetle infested pine barks

In this study, phenol–formaldehyde (PF) resins were synthesized using both bark extractives and phenol-liquefied barks from mountain pine beetle (Dendroctonus ponderosae Hopkins) infested lodgepole pine (Pinus contorta Dougl.). The thermal stability and thermal degradation kinetics of the bark-derived PF resins were investigated by thermogravimetric analysis (TGA). The structural changes in the bark-derived PF resins at different stages of the thermal degradation were studied using the Fourier Transform Infrared Spectroscopy (FTIR). Thermal stability of the post-cured bark-derived PF resins were similar to that of the lab PF resin but differed significantly from that of the post-cured commercial PF resin. Bark-derived PF resin made from bark extractives differed significantly in thermal stability and thermal degradation kinetics from the bark-derived PF resin made from the phenol-liquefied bark. The bark-derived PF resin made from the bark extractives showed a higher thermal stability.