EFFICACY OF ACIDIC AND ALKALINE SOLUTIONS OF ALKYLAMMONIUM COMPOUNDS AS

Solutions of alkylammonium compounds were modified by addition of various levels of acid (HC1) or alkali (Na2C03). Solution concentrations were designed to provide sub-toxic retentions of the alkylammonium compounds in treated poplar or pine wood blocks. The effect of acid or alkali addition to treating solutions was determined through increase or decrease in decay after treated wood was incubated with test fungi (brown-rot, white-rot, and soft-rot). Addition of low levels of acid (0.025-0.1 % w/w HC1) improved performance against basidiomycetes, and to a lesser extent soft-rot fungi. Addition of high levels of acid (1 % w/w HC1) further improved soft-rot control, but resistance of treated wood to basidiomycete attack was reduced. Addition of alkali to treating solutions generally led to increased loss of wood substance when treated wood was exposed to fungal attack. Results are discussed in terms of the effect of acid and alkali on the fixation process and subsequent macro- and micro-distribution of alkylammonium compounds in wood