Resistance to fungal decay of paraffin wax emulsion/copper azole compound system treated wood

Abstract

Poplar (Populus cathayana) is susceptible to fungal infection with white-rot fungus (Trametes versicolor (L.) Murrill.). The effects of paraffin wax emulsion and Copper Azole (CA) preservative treatment were studied in regard to the fungal resistance. A full-cell process was used to treat the samples with varying paraffin wax emulsion concentrations (0.5%, 1.0%, and 2.0%), CA concentrations (0.3% and 0.5%), and their six compound systems. The highest observed mass loss of decay was 64% for untreated wood. Paraffin wax emulsions played an important role in resisting the white-rot fungi. The CA preservative effectively improved the decay resistance of the wood, which obtained a mass loss between 1.1% and 3.2%. The compound systems showed a higher mass loss, compared to the CA treated wood. This was caused by the high concentration of paraffin wax emulsion, which inhibited the impregnation of CA in the compound system. The paraffin wax concentration increased, resulting in a decreased mass loss of compound systems treated wood. The white-rot fungi decay caused the wood cells to separate and serious degradation of the lignin, the hemicellulose occurred, as well as a slight degradation of the cellulose.