Tannin Extracts as a Preservative for Pine Thermo-mechanically Densified Wood


  • Nídia Niela de Lima Universidade Federal de Viçosa
  • Vinícius Resende de Castro Universidade Federal de Viçosa
  • Nayara Franzini Lopes Universidade Federal de Viçosa
  • Ítalo Lima Nunes Universidade Federal de Viçosa
  • Frances Alves Andrade Universidade Federal de Viçosa
  • Antonio José Vinha Zanuncio Universidade Federal de Uberlândia
  • Angélica de Cassia Oliveira Carneiro Universidade Federal de Viçosa
  • Solange de Oliveira Araujo University of Lisbon, Instituto Superior de Agronomia


Biodeterioration, Thermo-mechanical densification, X-ray densitometry, Preservatives, Tannins


Thermo-mechanical densification modifies wood to produce a more dense and resistant lignocellulosic material and may degrade extractives that contribute to the increased susceptibility of wood to attack by xylophagous organisms. This study evaluated the efficiency of tannin extracts of Acacia mearnsii in the treatment of thermo-mechanical densified pine wood in relation to physical, mechanical, and biological resistance (Cryptotermes brevis) properties. Pinus elliottii samples were pretreated with oxalic acid in a Parr reactor, then treated by diffusion in tannin solutions at concentrations 5, 10, and 15%, and finally hot pressed. The apparent density of the modified wood was 87.8% greater than that of the in natura wood (control) with tannins at 15%. The mechanical strength increased, especially the parallel compressive strength, which had an average increase of 169% for the wood with tannins at 10 and 15%, compared with the in natura wood. There was an increase in termite mortality and a reduction in damage for the modified wood treated with 15% tannins, obtaining the best results in mechanical and biological resistance and for the physical parameters. Thermal densification pine wood and preserved with tannin extractives proved to be a potential alternative as a high performance material.






Research Article or Brief Communication