ABSTRACT
Wood is composed by polymeric materials, with fire susceptibility. For applications, wood with better ignition resistance and lower fire stenght reduction is desirable. Enhancing of wood thermal properties can be achieved by means of right modification of wood by treatment. Thus, the microwave-assisted solvotermal process was implemented to modify the surface of the Pinus elliotttii wood with TiO2 in order to increase the resistance to flammability and thermal degradation through the retardation of carbonization. An alcoholic precursor solution with titanium isopropoxide was prepared and nanoparticles of TiO2 were crystallized to anatase on wood surface and interior at 140°C, for 60 minutes. Using Scanning Electron Microscopy, it was possible to demonstrate the uniform and homogeneous coating, and by Fourier transform infrared spectroscopy, it was possible to indicate presence of hydrogen bonds between the two materials. The formation of protective particle layer afforded greater stability and thermal resistance due to the ceramic character of TiO2. From the thermogravimetric analysis, 70% of weigh loss at 380°C and 11% of residual content at 700°C was verified, differently from the modified wood that at these temperatures reached 45% and 46%, respectively. Corroborating with these results, it was evident from the flame tests that wood with the presence of particles delayed about 7 times the moment of ignition. Thus, the microwave-assisted solvotermal process has great potential to transform wood and other porous materials into a less flammable material, maintaining its entire structure for a longer time when exposed to adverse conditions
Keywords
flame test; termal degradation; microwave system
