An experimental investigation of the pyrolysis behaviour of pine wood with different fire-retardant additives.

In the present study, with a view to decreasing the inherent fire risk associated with the usage of wood, the flame-retardant efficacies of some additives for wood samples were investigated. The additives included: 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), triphenylphosphine (TPP), diammonium hydrogen phosphate ((NH4)2HPO4) and sodium carbonate (Na2CO3). The test samples incorporating the flame-retardant additives were primarily evaluated by thermo-gravimetric analysis (TGA). It was found that the presence of DOPO imparted some beneficial effects, especially, in terms of increased energetic needs for the second-stage decomposition of the lingo-cellulosic material, coupled to an enhanced production of char residues. However, with the other additive systems, such as TPP, Na2CO3 and (NH4)2HPO4, the flame-retardant effect seemed to arise from increased char production with a concomitant effect on the energetic requirements for the decomposition pathways, especially, at a high temperature. In terms of to the conversion degrees, for samples PFC2, PFC3 and PFC4, stage one was found to extend over the conversion range of 0 ≤ α ≤ 0.65, corresponding to temperatures from 30 to 350 °C. In contrast, for samples PFC5, PFC6 and PFC7, stage one seemed to span over a conversion range of 0 ≤ α ≤0.55, during the same temperature range. Additionally, PFC2 exhibited maximum char residue, indicating it may represent a more effective formulation. Furthermore, a detailed kinetic analysis would be processed in the future. [ABSTRACT FROM AUTHOR]