Effects of phosphoramides on wood dimensional stability

To evaluate the dimensional stability of phosphoramide-reacted wood, wood was reacted with a mixture which was derived from compounding phosphorus pentoxide and each of 12 amines including alkyl, halophenyl, and phenyl amines in N,N-dimethylformamide. Dimensional stability of such reacted wood was analyzed by antishrink efficiency (ASE) using the water-soak method. Volumetric swelling and equilibrium moisture content (EMC) of phosphoramide-reacted woods were also determined after being maintained at 27°C and 30% RH, 27°C and 65% RH, and 21°C and 90% RH for 21 d. The Tesults revealed that phosphoramide-reacted woods had lower antishrink efficiency values than those of acetylated wood, expoxided wood, and isocyanated wood. Volumetric swelling and equilibrium moisture content of phosphoramide-reacted wood were increased when exposed to an environment with a higher relative humidity. Phosphoramides had less effect on improving the dimensional stability of wood.