Flammability of a softwood impregnated with alumina nanoparticles

Abstract

Micro- and nanoparticles of aluminum oxide (alumina) have been used to confer increased flammability to polymers. In the present study, different weight fractions of alumina nanoparticles were impregnated into a traditional softwood and the flammability of these treated woods was studied. Sodium polyacrylate (SPAC) was used as a surfactant and also as a positive control. The influence of the treatment in physical (apparent density), mechanical (static bending and hardness), and thermal (flame retardancy and thermal stability tests) characteristics were evaluated. The presence of alumina nanoparticles in the wood ultrastructure was confirmed by means of SEM/EDS analyses. Compared to the untreated pine wood and that wood impregnated with neat SPAC, the impregnation of alumina contents within 0.3–0.5 wt% reduced the flame spreading of the studied pine woods. Also compared to the untreated wood, similar thermal and mechanical properties were achieved. The studied pine wood became less flammable with alumina impregnation, and there was no detrimental effects to its mechanical properties.