Curing kinetics of phenol formaldehyde resin and wood-resin interactions in the presence of wood substrates

• Published in: Wood science and technology Vol. 38; no. 1; pp. 69 - 81
• Main Authors: He, G, Riedl, B
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.04.2004; Springer Nature B.V
• Subjects: Activation energy; Aldehydes; Applied sciences; Calorimetry; Chemical reactions; Condensation; Condensation resins; Conversion; Curing; Differential scanning calorimetry; Enthalpy; Exact sciences and technology; Fourier transforms; Hydroxyl groups; Kinetics; Organic chemistry; Phase transitions; Phenol formaldehyde; Phenol formaldehyde resins; Phenols; Polymer industry, paints, wood; Properties and testing; Reaction kinetics; Substrates; VOCs; Volatile organic compounds; Wood; Wood. Paper. Non wovens; Self condensation; Enthalpy; Populus tremula; Cellulose; Softwood; Formaldehyde; Pseudotsuga menziesii; Aceraceae; Dicotyledones; Angiospermae; Gymnospermae; Infrared spectrum; Resins; Activation energy; Betulaceae; Picea; Differential scanning calorimetry; Condensation reaction; Interaction; Hardwood; Experimental study; Salicaceae; Acer; Larix; Treatment; Fourier transform spectra; Coniferales; Spermatophyta; Kinetics; Betula
• ISSN: 0043-7719; 1432-5225
• DOI: 10.1007/s00226-003-0221-5

The curing kinetics of resol PF resin and resin–wood interactions in the presence of wood substrates have been studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The activation energy of cure of PF resin generally increases when PF resin is mixed with wood, mainly due to the decrease of the pH values resulting from the presence of wood. However, wood decreases the curing enthalpy of PF resin through diffusion and the change in the phase of the curing system, which suggests that the curing reactions reached a lower final degree of conversion for the mixtures of PF resin with wood than for the PF resin alone. Moreover, DSC curves and the variation of activation energy with conversion indicate that wood accelerates the addition reactions and retards condensation ones during the curing process of PF resin with wood. The study also revealed that almost no chemical reactions occur between PF resin and wood, but the secondary force interactions of hydroxyl groups between PF resin and wood have been detected. These most significant secondary forces can catalyze the self-condensation reactions of PF resin, although their effect is not vital on the curing kinetics of PF resin.