Phenol-urea-formaldehyde-tannin (PUFT) adhesives have been prepared by copolymerization at room temperature of pine bark tannins
with phenol-urea-formaldehyde (PUF) prepolymers prepared under varying operating conditions. Differential scanning calorimetry
(DSC) and dynamic mechanical analysis (DMA) have been used to analyse the curing of prepolymers and adhesives. DSC curves
were obtained at three different heating rates and, by means of the Model Free Kinetics isoconversional method, chemical conversion
vs. time at a given temperature was obtained. Mechanical conversion was calculated from DMA storage modulus data for those
adhesives which gave the best results for plywood and MDF boards.