Abstract:

The flame retardant with the anti elute ability is a major direction of research and exploitation of wood flame retardants today. The char yield and the thermodynamics parameters at different stages during the pyrolysis of the wood treated with phenol flame retardants were studied by the TG DTA thermo analysis. The results showed that the char yield of the Cunninghamia lanceolata wood treated with phenol flame-retardant differs with the substituting group on the phenol, the order of the fire retardants ability was-NH₂>-Br>-NO₂. The char yield of the wood treated with 2.6-Dibromo-4-nitorphend or 2,6-Dibromo-4-aminophenol that contained both nitrogen and bromine overtake that of the corresponding single substituted phenol derivative. After the elution experiment, the char yield loss of the wood treated with di Ammonium hydrogen phosphate was five times the char yield loss of the wood treated with 2.6-Dibromo-4-nitrophenol. The increase of the char yield after the fire retardant treatment was always corresponding to the depression of peak temperature, the decrease of activation energy and the increase of speed constant, but was in negative relation with these thermodynamics parameters. Therefore, the phenol substituted with amino and bromine could not only provide the strong fire retardant ability on wood but also provide the violent anti-elute ability. The fire retardant ability of nitrogen had close relation with its oxidation state in flame-retardant. Nitrogen and bromine had synergy in fire retardant treatment of wood, too. The fire retardant treatment also affected the hygroscopic ability of wood.

Key words: Wood, Flame-retardant, Thermodynamics, Phenol