Chemical Modification of Wood Products with Gaseous Alkylene Oxides

A procedure for alkoxylation of wood with gaseous alkylene oxides was developed, using solid wood samples and ethylene oxide catalyzed with trimethyl amine. The procedure consisted of an initial reaction step with wood, trimethyl amine and ethylene oxide, followed by evacuation of excess trimethyl amine. Several small additions of ethylene oxide were then made, followed by evacuation and steaming. Solid wood ethoxylated by this procedure was found to be less degraded by wood destroying fungi than was unmodified wood. Chips for particle board production were alkoxylated, according to the procedure, using ethylene oxide and propylene oxide, respectively. Particle boards were made from alkoxylated chips and evaluated with respect to swelling in water. As a comparison boards were also made from chips alkoxylated with liquid propylene or butylene oxide. Boards made from chips modified with gaseous alkylene oxides performed better than boards made from unmodified chips only when wood chips with a moisture content above that of oven-dried wood were alkoxylated. Chips alkoxylated with liquid alkylene oxides resulted in much better boards than chips alkoxylated with gaseous alkylene oxides.