Effects of termal treatment on the physical properties of Buchenavia sp. (branquilho) wood

Laysa Teles Vollbrecht,Rafael Rodolfo De Melo,Maúcha Fernanda De Mota Lima,Ricardo Pereira Soteil,Alexandre Santos Pimenta,Adriano Reis Prazeres Mascarenhas

doi:10.1590/s1678-86212022000100580

Abstract

Abstract This work aimed to evaluate the effect of heat treatment on the physical properties of wood from Buchenavia sp. The heat treatments were carried out at temperatures of 180 °C and 200 °C for 2 h. Apparent density (AD), basic density (BD), porosity (Ф), mass loss, longitudinal (LS), radial (RS), tangential (TS) and volumetric (VS) shrinkages and anisotropic factor (AF) were determined. The lowest values of basic density (0.67 g cm-3), apparent density (0.77 gcm-3), and porosity (43.3%) were observed for the wood treated at a temperature of 200 °C. Mass losses increased with increasing temperature and the highest values were observed under the condition of 200 °C (9.3%). The LS and AF was not affected by heat treatments. The mean values for RS (3.1%), TS (5.1%), and VS (9.1%) were reduced after the performance of heat treatments at temperatures of 180°C and 200°C, which did not differ from each other. The thermal treatments were able to reduce the dimensional instability of Buchenavia sp. Thermal treatments enhance the use of less prestigious Amazonian woods in the civil construction market.

Highlights

Wood is by far one of the materials more used by mankind from pre-historical times to the present day, mainly due to its excellent and versatile technological properties, which permit its application in several forms, such as: civil construction, flooring, furniture uses, watercraft, musical instruments, pulp and paper, source of chemicals and firewood, among other uses (FIGUEROA; MORAES, 2009; RAMAGE et al, 2017)
As pointed out by Percin, Peker and Atilgan (2016), when the wood is heated at a high temperature, it becomes more brittle and its mechanical strength decreases depending on the level and duration of the thermal treatment which is followed by a concomitant decrease in the wood density
More likely it occurred in the assessed material, despite no differences in density was observed after the thermal treatment, even though the heat promotes degradation of the wood cell leaving it susceptible to mechanical fatigue (FIGUEROA; MORAES, 2009)

Summary

Introduction

Wood is by far one of the materials more used by mankind from pre-historical times to the present day, mainly due to its excellent and versatile technological properties, which permit its application in several forms, such as: civil construction, flooring, furniture uses, watercraft, musical instruments, pulp and paper, source of chemicals and firewood, among other uses (FIGUEROA; MORAES, 2009; RAMAGE et al, 2017). According to Silva et al (2015), the benefits of heat treatments are majorly associated to the degradation of hemicelluloses, which are responsible for a significant role on sorption and desorption of water in the wood cell wall. This way, temperatures for heat treatment are usually in the range of 160 a 260 °C and the higher the temperature is greater will be the losses in mechanical strength of the wood, what can sometimes severely restrain its use for structural applications (ESTEVES; PEREIRA, 2009; SILVA et al, 2015; PERCIN; PEKER; ATILGAN, 2016; SANDBERG; KUTNAR, 2016)

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