SciELO - Scientific Electronic Library Online

 
vol.87 issue1Gestational diabetes: a risk of puerperal hypovitaminosis A?Physical attributes of ultisol of Brazil's northeastern semiarid under organic farming of wine grapes author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Anais da Academia Brasileira de Ciências

Print version ISSN 0001-3765

Abstract

CADEMARTORI, Pedro Henrique G. de; MISSIO, André L.; MATTOS, Bruno D.  and  GATTO, Darci A.. Effect of thermal treatments on technological properties of wood from two Eucalyptus species. An. Acad. Bras. Ciênc. [online]. 2015, vol.87, n.1, pp.471-481. ISSN 0001-3765.  http://dx.doi.org/10.1590/0001-3765201520130121.

The effect of thermal treatments on physical and mechanical properties of rose gum and Sydney blue gum wood was evaluated. Wood samples were thermally modified in a combination: pre-treatment in an autoclave (127°C - 1h) and treatment in an oven (180-240°C - 4h); and only treatment in an oven at 180-240°C for 4h. Chemical changes in the structure of woods were evaluated through infrared spectroscopy. Evaluation of physical properties was performed through mass loss, specific gravity, equilibrium moisture content and dimensional stability tests. Surface changes were analyzed through apparent contact angle technique and static bending tests were carried out to evaluate the mechanical behavior. Use of pre-treatment in autoclave affected the properties analyzed, however oven, resulted in the highest changes on wood from both species. Chemical changes were related to the degradation of hemicelluloses. Moreover, a significant decrease of hygroscopicity and mechanical strength of thermally modified woods was observed, while specific gravity did not significantly change for either of the species studied. The best results of decrease of wettability were found in low temperatures, while dimensional stability increased as a function of temperature of exposure in oven. The highest loss of mechanical strength was observed at 240°C for both species.

Keywords : hygroscopicity; chemical changes; wettability; heat treatment; mechanical strength.

        · abstract in Portuguese     · text in English     · English ( pdf )