Thermal, flammability and iso-conversional multiple heating rate kinetic studies of impregnated poplar wood veneers

Wood, one of the flammable materials, has been impregnated with varying concentrations of Cetyltrimethylammonium bromide (CTMAB) and Ammonium dihydrogen orthophosphate (ADHOP) via soaking method. The impregnation of chemicals in poplar wood veneers has been confirmed by weight gain percentage (WGP) and scanning electron microscopy (SEM) studies. The thermal behavior of samples has been studied by dynamic thermogravimetry (TG) analysis under nitrogen atmosphere. Non-isothermal, "model free" iso-conversional multiple heating rate methods viz. Ozawa-Flynn-Wall (O-F-W) and modified Coats-Redfern have been used to evaluate activation energy of selected samples. Thermal parameters like onset temperature, maximum mass loss rate (MMLR) and percentage char yield at 650 degrees C temperature have been used to appraise the flammability of wood and modified wood samples. The flammability of samples has also been determined by limiting oxygen index (LOI) and standards of Underwriters Laboratories (UL 94). The study depicts the synergetic effect of ADHOP on the flame retardant properties imparted by CTMAB on poplar wood samples.