Chemical changes of heat treated Pine and Eucalypt wood monitored by FTIR

Authors

  • B. Esteves Polytechnic Institute of Viseu
  • A. Velez Marques Superior Institute of Engineering of Lisbon
  • I. Domingos Polytechnic Institute of Viseu
  • H. Pereira Technical University of Lisbon

Keywords:

eucalyptus globulus, FTIR, heat treatment, pinus pinaster

Abstract

A hardwood, Eucalyptus globulus Labill., and a softwood Pinus pinaster Aiton., were heat treated at temperatures between 170 and 210ºC in an oven and in an autoclave. The samples were pre-extracted with dichloromethane, ethanol and water and ground prior to Fourier Transform Infrared (FTIR) spectroscopic analysis.

The heat treatment caused significant changes in the chemical composition and structure of wood, in lignin and polysaccharides. Hemicelluloses were the first to degrade as proved by the initial decrease of the 1730 cm-1 peak due to the breaking of acetyl groups in xylan. Hardwood lignin changed more than softwood lignin, with a shift of maximum absorption from 1505 cm-1 to approximately 1512 cm-1 due to decrease of methoxyl groups, loss of syringyl units or breaking of aliphatic side-chains. The macromolecular structure becomes more condensed and there is a clear increase of non-conjugated (1740 cm-1) in relation to conjugated groups (1650 cm-1). However, the changes induced by the thermal treatment are difficult to monitor by FTIR spectroscopy due to the different chemical reactions occurring simultaneously.

Downloads

Download data is not yet available.

Author Biographies

B. Esteves, Polytechnic Institute of Viseu

Centre of Studies in Education, Technologies and Health, School of Technology of Viseu, Polytechnic Institute of Viseu,
Campus Politécnico Repeses, 3504-510, Viseu, Portugal.

A. Velez Marques, Superior Institute of Engineering of Lisbon

Research Centre for Chemical Engineering and Biotechnology (CIEQB), Superior Institute of Engineering of Lisbon, Lisbon, Portugal.

I. Domingos, Polytechnic Institute of Viseu

Centre of Studies in Education, Technologies and Health, School of Technology of Viseu, Polytechnic Institute of Viseu,
Campus Politécnico Repeses, 3504-510, Viseu, Portugal.

H. Pereira, Technical University of Lisbon

Forest Research Centre, School of Agronomy, Technical University of Lisbon, Lisbon, Portugal.

How to Cite

Esteves, B., Velez Marques, A., Domingos, I., & Pereira, H. (2014). Chemical changes of heat treated Pine and Eucalypt wood monitored by FTIR. Maderas-Cienc Tecnol, 15(2), 245–258. Retrieved from http://revistas.ubiobio.cl/index.php/MCT/article/view/1291

Issue

Section

Article