DYNAMIC THERMOMECHANICAL ANALYSIS AS A CONTROL TECHNIQUE FOR THERMOSET BONDING OF WOOD JOINTS

Dynamic thermomechanical analysis was used to control and investigate the viscoelastic behaviour, as expressed by the dynamic storage modulu s and by tan delta, of wood joints bonded with crosslinking thermosett ing adhesives. Phenol formaldehyde (PF), melamine-urea-formaldehyde (M UF), resorcinol-formaldehyde (RF), tannin-formaldehyde (TF) and tannin -hexamethylenetetramine (TH) were the resins used. The approach presen ted indicated that three parameters, defined as the stiffening coeffic ient, the softening coefficient and the degradation coefficient, may b e of interest in comparing wood joints bonded with different adhesives . (C) 1998 Elsevier Science Ltd. All rights reserved.