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Madera y bosques
versão On-line ISSN 2448-7597versão impressa ISSN 1405-0471
Madera bosques vol.11 no.1 Xalapa Mar. 2005
https://doi.org/10.21829/myb.2005.1111261
Artículos científicos
Resistencia a la pudrición y estabilidad dimensional de la madera acetilada con y sin catalizador
1 Valle Airoso 112, Fracc. San Javier, Pachuca, Hidalgo, México, 42070. mmiguelgp@netscape.net
2 INIFAR investigador Titular. C. E. San Martinito km 56.5, Carr. Fed. Méx.-Pue., 74100, Tlahuapan, Pue., México. amadorh@computex.com.mx.
El propósito del presente trabajo fue evaluar la resistencia a la pudrición blanca (Coriolus versicolor) y café (Coniophora puteana) en madera acetilada de pino escocés (Pinus sylvestris) y el efecto de la piridina como catalizador. Las pruebas de biodegradación se realizaron sobre cultivos puros en malta agar al 4% por 12 semanas, conforme a lo establecido en la norma europea EN113. Adicionalmente, se comparó la estabilidad dimensional de la madera impartida por la acetilización, en sistemas de modificación química catalizada y sin catalizar. La modificación química proporcionó resistencia a la biodegradación de la madera contra hongos de la pudrición café y blanca. Se requirió de un nivel de acetilización mayor para inhibir la pudrición café, en comparación con el requerido para impedir la pudrición blanca. Los patrones de pudrición y las pérdidas de peso registradas indicaron que la piridina como catalizador no influyó en la resistencia a la pudrición de la madera acetilada, cuando los resultados fueron comparados dentro de la misma especie de hongo. La estabilidad dimensional impartida por la acetilización, medida por la eficiencia de antiexpansión (ASE), resultó satisfactoria en ambos sistemas de reacción, aunque el sistema no catalizado fue significativamente más eficiente. Se concluyó que la ganancia porcentual en peso, debida a la modificación química, es un buen indicador del grado de expansión parcial permanente de los bloques de madera, así como de la estabilidad dimensional y la resistencia a la pudrición de la madera acetilada.
Palabras clave: Acetilación; Coniophora puteana; Coriolus versicolor; modificación química; pino escocés
This work was aimed at assessing the decay resistance of acetylated Scots pine (Pinus sylvestris) sapwood against white (Coriolus versicolor) and brown (Coniophora puteana) rot fungi and the effect of pyridine as catalyst. Samples were decayed over pure cultures on 4% malt agar for twelve weeks, following the general procedures of the European Standard EN113. Additionally, the dimensional stability of wood given by acetylation was compared in the catalysed and uncatalysed chemical modification systems. The chemical modification provided resistance to the biodegradation of the wood against brown and white rot fungi. A greater level of acetylation was required to inhibit the brown rot, in comparison with the required level to prevent the white rot. The decay patterns and the weight loss recorded indicated that, pyridine as a catalyst did not influence the decay resistance of acetylated wood, when results were compared within the same fungus species. The dimensional stability provided by acetilización, and measured by the antiswelling efficiency (ASE), was satisfactory in both reaction systems, although the uncatalysed system was significantly more efficient. It was concluded that the weight percentage gain due to chemical modification is a good indicator of the degree of permanent partial swelling of the wood blocks, as well as of the dimensional stability and the resistance to decay of the acetylated wood.
Keywords: Acetylation; Coniophora puteana; Coriolus versicolor; chemical modification; scots pine
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Recibido: 15 de Abril de 2005; Aprobado: 07 de Junio de 2005
Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons
