Anatomical identification and evaluation of improvement on dimensional stability in amazonian species thermal rectification

ABSTRACT

Thermal rectification is a method that is used to increase the physical, chemical and mechanical properties of the wood, exposing samples to high temperatures. In the present study, the improvements and implications provided by thermal rectification in the Amazon species Angelim Vermelho, Cedro, Quaruba and Muiracatiara were evaluated, regarding changes in physical properties, changes in color, possible cracks, in addition to the anatomical identification of these species. Thermal rectification was carried out at temperatures of 130, 150 and 170 °C. The greatest changes in color were observed in the species Angelim Vermelho and Muiracatiara. The appearance of cracks was observed mainly at 170 °C. The loss of mass was directly proportional to the use of higher temperatures. Changes in the density of the wood were verified after the thermal rectification process, in which Angelim Vermelho stands out following a linear pattern with reduced density according to the increase in applied temperatures. The tests of the volumetric variation revealed a reduction of the hygroscopicity of the treated species in relation to the controls, except for the treatment of Angelim Vermelho at 130 ºC. The anatomical analysis allowed the identification up to species level, being the studied species: Dinizia excelsa Ducke, Cedrela fissilis Vell, Astronium ulei Mattick and Vochysia maxima Ducke, for Angelim Vermelho, Cedro, Muiracatiara and Quaruba.

Keywords
Thermal rectification; Amazonian Species; Wood Anatomy