EVALUATION OF BORAX AND BORIC ACID AS FLAME RETARDANT ON SELECTED TIMBERS

Abstract

This work aimed at evaluating the effectiveness of borax, boric acid, and zinc chloride as fire retardant chemicals in timber. Fire which is the most resourceful gift of nature has led to the loss of lives and properties also wood plays an important part in fire outbreak, that is why the need for flame retardant chemicals are very important. Three species of timber which are iroko, mahogany, and arborea was selected for this study with a total of 18 splints were prepared from each timber species for analysis purpose which led to a sum total of 72 splints of timber used for this study, and each splint had a dimension of 20.0cm×1.0cm×0.5cm. Each treatment chemicals was prepared into five different concentrations of 0.05, 0.1, 0.5, 1.0, and 2.0mol/L. Five splints of each timber were immersed in a solution of each of the chemicals in their different concentrations and allowed to stand for 24 hours for thorough impregnation, while a sixth untreated splint serve as a control in each case. After which both the treated and untreated splints were subjected to fire performance test using time based parameters such as absorptivity, ignition time, flame propagation rate, after-glow time, and char formation so as to analyze the effect of borax, boric acid, and zinc chloride treatment on such parameters in the timber. The results obtained showed that the absorptive capacity of the timber species increased with increase in the concentration of the retardant chemical with the peak absorption observed in borax treated timbers at 2.0mol/L concentration. The ignition time of the treated timbers increased in the order Arborea>iroko> mahogany, while the flame propagation rate and after- glow time generally decreased as expected compared with the control, and also the timbers treated with retardant chemicals have higher fire performance or resistance to burning than untreated timbers. It was recommended that since fire retardant chemicals have the potential of increasing the resistance of wood burning, it is therefore recommended that fire inhibitory chemicals such as these should be incorporated into timbers and their derived products to avoid incidence of fire outbreak. It was therefore concluded that borax, boric acid and zinc chloride are effective as fire retardant chemicals with borax having greater proficiency.