Study of ignition parameters and the thermooxidative degradation of wood in the presence of flame retardants with a bioprotective effect

Introduction. This study aims to carry out comprehensive comparative research of thermal degradation and inflammation parameters of timber covered with fire resistant biological flame retardants of different chemical composition. We also looked at the efficiency and the action mechanism of the latter. Materials and methods. As the objects of research, the means were selected - phosphorase-containing water-soluble compounds of the nanoscale series, complex biocides and special bioplasticizers (Agent 1) and water-soluble nanoscale diammonium hydrophosphate (Agent 2) applied to pine wood by surface treatment and deep impregnation methods. Results and discussion. Thermogravimetric studies of wood treated with flame retardants have shown that its decomposition occurs in the following temperature ranges: 30-150°C - the process of loss of moisture by wood; 150-400°C - the effect of protective mechanisms of the compositions, as well as the process of decomposition of the main components of wood (hemicellulose, cellulose, lignin) and the formation of a coke layer; 400-800°C - the process of gradual burnout of the coke layer taking into account its thermophysical characteristics up to the ash residue. It has been established that both flame retardants act by the mechanism of catalytic dehydration and reduce the rate of decomposition of wood from 29 to 10%/min. Conclusion. The features of the thermal decomposition of wood protected by two different chemical composition and method of its processing means are determined. The parameters of the flammability of pine wood treated with fire-protective compounds by surface and deep impregnation were obtained, which indicate their high efficiency, which is confirmed by the values of the coke residue at 400°C, the nature of DTG peaks and DSC curves. The possibility of using the obtained materials from wood for interior decoration and cladding of facades of buildings that meet regulatory requirements for their safe use is shown.