Passive fire protection of wood using some bio-derived fire retardants

In the present paper, we report on some preliminary findings relating to the passive fire protection efficiencies of some bio-inspired substrates, which included: starch, chitosan, rice bran and fish gelatin. With a view to enhancing the passive fire protection attributes of the substrates, we prepared formulations of them with both inorganic and organic additives, the latter constituted phosphorus-containing compounds with the phosphorus atom in different chemical environments. We also chose several thermal and calorimetric techniques for evaluating the efficacies of such formulations, such as: thermo-gravimetric analysis (TGA), pyrolysis combustion flow calorimetry (PCFC), a proprietary ignition propensity test and cone calorimetry. In addition, with a view to deciphering the elements of condensed phase mechanism, we carried out an estimation of the extents of phosphorus retention (through inductively-coupled/optical emission spectroscopy: ICP/OES) and chemical nature (via solid-state NMR and Raman spectroscopies) of the char residues that were obtained through cone calorimetric runs. The preliminary results of our investigations indicated that formulations based on fish gelatin endowed with the best fire protection property, followed by chitosan, whereas potato starch and rice bran seem to be ineffective as fire proofing agents.