Chemical characterization and biological resistance of thermally treated bamboo

• Published in: Construction & building materials Vol. 262; p. 120033
• Main Authors: Maria Silva Brito, Flávia, Benigno Paes, Juarez, Tarcísio da Silva Oliveira, José, Donária Chaves Arantes, Marina, Dudecki, Larissa
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 30.11.2020
• Subjects: Biological assay; Chemical composition; Dendrocalamus giganteus; Heat treatment; Heat treatment; Chemical composition; Dendrocalamus giganteus; Biological assay
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2020.120033

•Heat treatment increased lignin and extractives and decreased holocelulose of bamboo.•Heat treatment improved biological resistance of bamboo caused by brown rot fungi.•Heat treatment not improved biological resistance of bamboo to xylophagous termite. The aim of this study was to evaluate the chemical characteristics and biological resistance of thermally treated bamboo to decay fungi and xylophagous termites. Four stalks were collected in adulthood and cut every 2.10 m, divided into 50 cm parts, and then divided into four sections (slats) in the longitudinal direction. The slats were immersed in water for 10 days and air seasoned. The slats were processed into laminas with dimensions of 0.5 × 3.5 × 45 cm (thickness × width × length) and thermally treated at 140, 160, 180 and 200 °C for one hour at each temperature and compared those oven dry to 100 °C (control). Chemical analysis and testing of natural resistance involved the random collection of samples of thermally treated laminas and control with dimensions of 0.5 × 2.0 × 2.0 cm (thickness × width × length), which were classified by temperature. Bamboo decay resistance was tested with two brown rot fungi (Postia placenta and Gloeophyllum trabeum) and one species of subterranean termite (Nasutitermes corniger). The concentrations of extractives and total lignin increased with increasing temperature, and the holocellulose content was reduced. This may decrease the mechanical strength of bamboo and bamboo composites; but on the other hand, will increase your resistance to decay when exposed to more severe environmental conditions. Ultimately, there was a gain in natural resistance from temperature treatments of 140 °C to the tested fungi. To the termite, the heat treatments not provided improvement in biological resistance of the bamboo.