[TC2015] applicability of medium boiling fraction of flash pyrolysis condensates in phenolic resins

Fossil-based phenol is used to a large extend to produce phenol-formaldehyde (PF) resins, which are most commonly applied in engineered wood products such as plywood. Pyrolysis oil from straw pyrolysis might be a suitable bio-based substitute for such applications. By staged condensation of flash pyrolysis vapors, a phenolic monomers concentrated fraction could be produced. This fraction was used for the production of several PF resins with different recipes and degrees of substitution. Resulting resins were analyzed for free formaldehyde and dynamic viscosity as well as being characterized by curing behavior within a differential scanning calorimetry experiment. Finally, tensile strength specimen samples were made for testing according DIN EN 205. Bioresin tensile strength was found to lay in the range of 7-8 N/mm2, which is below but close to the minimum value of 10 N/mm2 for wood adhesive application.