Curing kinetics of nano cupric oxide (CuO)-modified PF resin as wood adhesive: effect of surfactant

Abstract

The effect of nano cupric oxide (CuO) in combination with surfactants on the curing kinetics of phenol-formaldehyde (PF) resin, as well as the bonding strength of plywood prepared using the modified resin was investigated in this study using dynamic and isothermal differential scanning calorimetry. The result showed that the incorporation of nano CuO along with alkane surfactant made in the laboratory clearly reduced the apparent activation energy of the PF resin and improved the addition and condensation reactions of the PF resin. Inclusion of the surfactant had the further effect of compensating the influence of diffusion control caused by nano CuO alone. The shear strength of plywood suggested that the addition of nano CuO (1%) alone or in combination with alkane surfactant (0.55%) or sodium lignosulfonate (0.55%) in the PF resin mixture was sufficient to meet the requirement of wood-based composites manufacturing.

Keywords:

• phenol-formaldehyde resin
• nanosize cupric oxide
• surfactant
• curing kinetics
• differential scanning calorimetry (DSC)

Acknowledgment

The authors express their gratitude to the National Natural Science Foundation of China (grant 31100423) for financial support. We also wish to thank Mr. Kevin Gleason from US, for his precious help on English writing improvement of this paper.