Cure of Phenol-Formaldehyde Adhesive in the Presence of CCA-Treated Wood by Differential Scanning Calorimetry

Chromated copper arsenate (CCA) preservatives interfere with bond formation of phenolic-based adhesives on CCA-treated southern pine. Ions of chromium (Cr+3) and copper (Cu+2) are known to complex with phenol and formaldehyde, affecting the rate of cure of the resin. Differential scanning calorimetry (DSC) was used to thermally analyze the cure of a commercial phenol-formaldehyde adhesive in the presence or CCA-treated wood, solutions of CCA preservative, and solutions of model compounds containing ions of Cr+6, Cr+3, Cu+2, and As+5. The DSC thermograms indicated that free metallic ions in solution can accelerate the cure of a portion of the adhesive at less than normal temperatures. However, when the CCA preservative was chemically "fixed" within the southern pine wood, accelerated cure of the adhesive did not occur