Wood modification with phenolic resin is widely and commercially used to improve certain wood properties such as durability, certain mechanical properties or dimensional stability due to hydrophobic properties of the resin. Depending on the phenolic resin formulation (e.g. used catalyst, molecular weight or pH value) different characteristics are noticed. The chemical composition of various wood species can differ and thus, can influence the curing reaction of phenolic resins impregnated in wood.
In this study the process parameters for curing behavior of two phenolic resins impregnated in thin beech (Fagus sylvatica L.) veneer was determined. Two commercial available phenolic resins with different molecular weight where observed. The curing temperature of phenolic resin impregnated in thin beech veneer is determined by using differential scanning calorimetry. Furthermore the curing behavior is observed by shear oscillations measurements. Thereby the transformation of viscosity attributed to the curing steps of phenolic resin mixed with milled wood flour. The starting temperature of polycondensation is determined by shear oscillation measurement. Subsequently, specimens of (60 x 60 x 0.6) mm were impregnated with each PF and cured for various durations (20, 60, 90 min). For verification of the degree of polymerization a leaching tests were accomplished. In order to compare the applied phenolic resins, the WPG is determined.
Keywords: phenolic resins, beech veneer, curing behavior, leaching
Authors
Kampe A.
Eberswalde University for Sustainable Development – University of Applied Sciences, Eberswalde, Germany
Franke T.
Eberswalde University for Sustainable Development – University of Applied Sciences, Eberswalde, Germany
Herold N.
Eberswalde University for Sustainable Development – University of Applied Sciences, Eberswalde, Germany
Pfriem A.
Eberswalde University for Sustainable Development – University of Applied Sciences, Eberswalde, Germany
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