Síntese e aplicação de partículas de óxido de alumínio visando a proteção da madeira

Abstract

In a technological daily that seeks more for economically and environmentally correct products aiming to supply the demand of several sectors, the use of aluminum oxide particles becomes a promising alternative aiming its use for the protection of wood. These particles are characterized by being widely used in various industrial sectors of society, such as electronics, catalysts and the formation of composite materials. Even though it has a wide range of uses, the application of aluminum oxide particles in their most stable form to protect wood is very little explored. Considering that this renewable material is combustible, and has an organic origin, itself become susceptible to degradation by xylophagous agents (such as fungi and termites) and by environmental agents (UV radiation and rain). Thus, the application of ceramic particles, such as Al2O3, presents itself as a promising alternative to mitigate these undesirable effects. In this context, the objective of this research was to synthesize particles of Al2O3 by the methods of combustion and biosynthesis, and after to apply on the Pinus elliottii Engelm specie analyzing changes in physical, mechanical, thermal and chemical properties, and in the natural durability of wood after exposure to xylophagous and environmental agents. To obtain the particles, the combustion synthesis was performed using urea and nonahydrate nitrate as reagents, while biosynthesis was carried out with babassu vegetable oil (Orbignya phalerata Mart. Ex Spreng.). It was observed that the combustion method made it possible to obtain crystalline particles and alpha phase (α), which is the most stable, while by the biosynthesis method, an amorphous material was obtained. After the impregnation inside the wood and performing all the characterizations, it was seen that the particles improved the performance of the wood when subjected to a flame retardation test, as well as, inhibited the development of the decaying fungi Trametes versicolor and Gloeophyllum trabeum due to the formation of a physical barrier in wood, proving to be efficient for these purposes. Regarding the physical and mechanical properties of artificially weathered wood, that was not impregnated with particles suffered greater variations due to the deterioration caused by artificial weathering, mainly on the surface of the wood. Therefore, this treatment with the impregnation of Al2O3 particle can be recommended mainly in order to reduce flammability and protect the wood from attack by xylophages