Tesis
Efeito da acetilação nas propriedades tecnológicas da madeira de Jacarandacopaia
Fecha
2019-02-28Registro en:
BAUFLEUR, Andressa Midori Yamauchi. Efeito da acetilação nas propriedades tecnológicas da madeira de Jacarandacopaia. 2019. 55 f. Dissertação (Mestrado em Ciências Florestais e Ambientais) - Universidade Federal de Mato Grosso, Faculdade de Engenharia Florestal, Cuiabá, 2019.
Autor
Stangerlin, Diego Martins
http://lattes.cnpq.br/8510628107164043
Stangerlin, Diego Martins
007.731.880-37
http://lattes.cnpq.br/8510628107164043
Pereira, Bárbara Luísa Corradi
086.609.356-75
http://lattes.cnpq.br/4460699728513037
007.731.880-37
Costa, Alexandre Florian da
303.515.020-68
http://lattes.cnpq.br/4300200185894332
Institución
Resumen
Based on the assumption that the chemical modification, specifically the
acetylation method, results in an improvement in the wood properties due
to the alteration of the basic molecular structure of the cell wall components,
this work had as objective to prove this efficiency. For this, were obtained
infrared spectra with Fourier transform for qualitative analysis of the
chemical modifications provided by the acetylation. In addition, the
alterations provided in the Jacaranda copaia wood were evaluated in
relation to the following quantitative parameters: mass gain, colorimetric
properties (L*, a*, b*, C and h*), physical properties (apparent and basic
density, absorption in water and volumetric swelling), mechanical resistance
(Rockwell hardness) and resistance to biodeterioration (durability to attack
of rotting fungi and termites).The acetylation of Jacaranda copaia wood was
carried out by immersion of samples in acetic anhydride, being evaluated 5
treatments: a) control (non-acetylated); b) acetylation for 2 hours; c)
acetylation for 4 hours; d) acetylation for 6 hours; e) acetylation for 8 hours;
all with a constant reaction temperature of 90°C. The acetylated wood
presented a mass gain between 18 and 21%, in order to provide an increase
in its density, compared to non-acetylated wood. It was evidenced the
chemical modification in the structural components of the acetylated wood,
through the increase of the peaks in the bands 1735, 1375 and 1250 cm-1
referring to the addition of acetates groups. Regarding the colorimetry, the
darkening of acetylated wood was verified in all the treatments. Acetylation
improved the dimensional stability of the Jacaranda copaia wood, with
reduction in absorption and volumetric swelling for 2h, 24h and even total
saturation in water. Regarding the Rockwell hardness, the acetylation
provided an increase in the resistance to the wood superficial penetration.
Acetylated wood showed a decrease in mass loss when submitted to
laboratory accelerated rotting tests for fungi of white rot (Trametes
versicolor) and brown rot (Gloeophyllum trabeum) in all treatments, but it
was more expressive for 8 hours acetylation. There was no loss of mass for
the attack of termites Nasutitermes sp in all treatments for acetylated wood.