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Báo cáo lâm nghiệp: " Comparison of the hygroscopic behaviour of 205-year-old and recently cut juvenile wood from Pinus sylvestris L."

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: " Comparison of the hygroscopic behaviour of 205-year-old and recently cut juvenile wood from Pinus sylvestris L." | Ann. For. Sci. 63 2006 309- 317 INRA EDP Sciences 2006 DOI 10.1051 forest 2006010 309 Original article Comparison of the hygroscopic behaviour of 205-year-old and recently cut juvenile wood from Pinus sylvestris L. Luis García ESTEBANa Francisco García FERNÁNDEZb Antonio Guindeo CASASÚSa Paloma De PALACIOS De PALACiOSa Joseph Grilc a Universidad Politécnica de Madrid Departamento de Ingeniería Forestal Escuela Técnica Superior de Ingenieros de Montes Cátedra de Tecnología de la Madera Ciudad Universitaria s n 28040 Madrid Spain b Asociación de Investigation Técnica de las Industrias de la Madera y el Corcho Flora 3 - 2 28013 Madrid Spain c Laboratoire de Mécanique et Génie Civil Université Montpellier 2 France Received 4 April 2005 accepted 27 September 2005 Abstract - The hygroscopic response of the juvenile wood of Pinus sylvestris L. from recently cut trees from the Valsaín Forest in Segovia Spain new wood was compared to that of the juvenile wood of the same species used in roof rafters installed at the end of the eighteenth century old wood which came from the same forest. The 35 C isotherms were plotted using the saturated salts method and the mathematical fit used was the GAB model. The infrared spectrums and the X-ray diffractograms were used in order to study the possible chemical variations and crystallinity indices of the cell wall. The adsorption-desorption loop of the old wood is above the loop of the new wood although the hysteresis coefficient is higher in the old wood. The peaks corresponding to the -OH groups are similar although the degree of crystallinity is significantly lower in the old wood. While cellulose crystallinity differs between the old and new wood and has a major influence on wood hygroscopicity other modifications in the amorphous components of the cell wall may have contributed to the changes in hygroscopicity between the old and new wood. hygroscopicity sorption isotherm juvenile wood Fourier transform infrared spectroscopy FTIR .