Desempenho da Resistência à Biodeterioração e das Propriedades Físicas da Madeira de Tauari (Couratari sp.) Modificada Termicamente

Abstract

Some Amazonian woods have low commercial value, often due to a wrong association between low natural durability and light color, being classified as "white woods." Thermal modification (TM) is a process capable of altering wood properties and improving its performance in service, such as increasing biological durability and dimensional stability. This study aimed to evaluate the effect of TM, in an open system, on the physical properties and resistance to biodeterioration, under laboratory conditions, of tauari wood (Couratari sp.). Five treatments were analyzed: untreated and thermally modified wood (TMW) at 180°C, 190°C, 200°C, and 210°C. Wood was assessed regarding chemical composition (cellulose, hemicelluloses, lignin, total extractives, and ashes); physical properties (apparent density, equilibrium moisture content, and total swelling) and associated indicators (moisture exclusion efficiency – MEE; anti-swelling efficiency – ASE); and resistance to biodeterioration by white rot fungus (Trametes versicolor) and termites (Nasutitermes corniger and Cryptotermes brevis). TM, mainly at 210°C, altered the chemical composition and increased the durability class in the test with T. versicolor, where the treatments at 190°C, 200°C, and 210°C were classified as very durable (Class 1). TM at 210°C is primarily recommended, as this treatment also yielded better results in reducing hygroscopicity and increasing dimensional stability.