The objective of this research was to improve the fire retardant and fungal resistant properties of wood in one treatment using a phosphorus pentoxide-amine system. Phosphorus pentoxide and sixteen amines including alkyl, halophenyl and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides, were reacted with wood. The characteristics of phosphoramide-reacted-wood, analyzed by Fourier Transform Infrared Analysis, Energy Dispersive X-ray Analysis, and Elemental Analysis, showed that reaction between wood components and phosphoramide varied with the chemical nature of the phosphoramides. Alkyl phosphoramide-reacted-woods had more weight loss with water leaching than that with acetone leaching. In contrast, halophenyl phosphoramide-reacted-woods and most of the phenyl-phosphoramide-reacted-woods lost more weight with acetone leaching than that with water leaching. Fire retardancy of phosphoramide-reacted-woods analyzed by Differential Scanning Calorimetry demonstrated that the modification can lower the onset of an endotherm and decrease the heat of combustion and heat flow. Phosphoramide-reacted-woods decreased pyrolysis temperatures and increased char yields compared to unreacted wood as monitored by Thermogravimetric Analysis. Most of the phosphoramide-reacted-woods had higher char yields than that of wood impregnated with diammonium phosphate. Fungal resistance of the phosphoramide-reacted-woods revealed that phosphoramides were more effective in preventing white-rot attack than brown-rot attack. Phosphoramide-reacted-woods showed low Antishrink Efficiency values, which indicate low dimensional stability.; In summary, thermal and fungal resistance of wood was effectively improved by reacting with phosphoramides. Wood reacted with phosphorus pentoxide and 4-nitroaniline had the best result among all phosphoramide treatments.
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