Efeito das variáveis do tratamento térmico nas propriedades da madeira de Eucalyptus sp.

• Ano de defesa: 2012
• Autor(a) principal: Soratto, Déborah Nava
• Orientador(a): Vital, Benedito Rocha
• Banca de defesa: Carvalho, Ana Márcia Macedo Ladeira , Araújo, Solange de Oliveira , Santos, Rosimeire Cavalcante dos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Ciência Florestal
• Departamento: Manejo Florestal; Meio Ambiente e Conservação da Natureza; Silvicultura; Tecnologia e Utilização de
• País: BR
• Palavras-chave em Português: Termorretificação; Vácuo; Nitrogênio; Temperatura; Análise termogravimétrica
• Palavras-chave em Inglês: Heat Treatment; Vacuum; Nitrogen; Temperature; Thermograviment analysis
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::TECNOLOGIA E UTILIZACAO DE PRODUTOS FLORESTAIS
• Link de acesso: http://locus.ufv.br/handle/123456789/3121

The heat treatment is used with various objectives, such as providing greater dimensional stability, greater resistance to fungal degradation and increased surface hardness. Heat treatments have the effect of reducing the hygroscopicity of the wood through the degradation of its constituent which are more hydrophilic hemicelluloses, reducing the ability to exchange water with the environment, are also minimized the problems of shrinkage and swelling. The objective of this study was to investigate the effect of varying the heat treatment in hygroscopic equilibrium moisture content, density, shrinkage, modulus of rupture and elasticity, hardness Janka strength in the glue line, the chemical composition and properties of wood in thermogravimetric Eucalyptus sp.. The woods were heated in a vacuum oven, in one oven with nitrogen and vacuum and nitrogen, the latter combination, heated with temperature levels. The temperatures used were 140, 180 and 220°C, and treatment time was 6 hours. The experiment was carried out according to a randomized design. Data were subjected to analysis of variance and, when established differences between them, were applied Tukey and Dunnett tests. In the thermogravimetric analysis, the greatest amount of residual mass was found that the treatment method used and with nitrogen and temperatures at 220°C. The results indicated that heat treatments employed, were effective in reducing the moisture equilibrium moisture mainly to the temperature of 220°C then with increased dimensional stability of wood. For mechanical properties, the effects of various treatments resulted where there was an increase in the treatment Janka hardness in the treatment to 140°C. The content of extractives, total lignin and holocellulose showed significant changes only 220°C temperature, in the three methods.