Coloring characteristics of in situ lignin during heat treatment

Chen, Yao; Fan, Yongming; Gao, Jianmin; Houkun, Li

doi:10.1007/s00226-010-0388-5

Cited by 63 publications

(43 citation statements)

References 16 publications

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“…Reflectance spectroscopy provides a powerful tool to characterize wood chromophores and changes in their concentration correlating to the discoloration of wood veneer during light irradiation [40]. The reflectance curve (Fig.…”

Section: Effect Of Radiation Time On the Surface Reflectance Changes mentioning

confidence: 99%

Surface photo-discoloration and degradation of dyed wood veneer exposed to different wavelengths of artificial light

Liu

Ling-min

Gao

et al. 2015

Applied Surface Science

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Section: Effect Of Radiation Time On the Surface Reflectance Changes mentioning

confidence: 99%

Surface photo-discoloration and degradation of dyed wood veneer exposed to different wavelengths of artificial light

Liu

Ling-min

Gao

et al. 2015

Applied Surface Science

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“…La condensación de las moléculas de tanino, la oxidación de los grupos hidroxilos en moléculas flavonoides (Yongming et al 2010), la formación de productos de la degradación de los polímeros de la madera (Sundqvist y Morén 2002), la formación de quinonas por la caramelización de las holocelulosas (Tjeerdsma et al 1998, Boonstra y Tjeerdsma 2006), y la formación de productos de condensación y oxidación de la lignina (Yao et al 2012) provocan el cambio de color. Yongming et al (2010) mencionan que al eliminar los extraíbles se puede disminuir la variación de los parámetros de color.…”

Section: Efecto Del Tratamiento En El Colorunclassified

Propiedades químicas, color y humectabilidad de partículas de Laureliopsis philippiana (tepa) con y sin tratamiento térmico

H³

et al. 2013

Maderas, Cienc. tecnol.

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El propósito de este trabajo fue determinar el efecto de un tratamiento térmico, en una atmósfera saturada de vapor de agua, en partículas de madera de la especie Laureliopsis philippiana. Las partículas fueron tratadas en autoclave a 150 ºC por 90 minutos y a una presión de 430 kPa, la cual se generó durante el proceso por la evaporación del agua en el autoclave herméticamente cerrado. Se determinaron la cantidad de extraíbles en soda, etanol tolueno, agua caliente y fría, así también, los porcentaje de celulosa, holocelulosa y lignina, el valor pH, los porcentajes de ácidos volátiles y solubles en agua, y la capacidad tampón, tanto para partículas sin tratamiento como con tratamiento. Para las partículas con tratamiento térmico, se encontró un aumento en el porcentaje de extraíbles, de celulosa, y de ácidos volátiles y lavables, así como también, un aumento de la acidez y de una mayor capacidad tampón, en comparación con las partículas sin tratamiento. El tratamiento térmico produjo un cambio de color en las partículas y una reducción de la humectabilidad. Debido a los cambios químicos encontrados en las partículas tratadas, estas presentarían ventajas en la fabricación de tableros de partículas, favoreciendo el fraguado de la ureaformaldehído. Palabras claves:Composición química, acidez, Laureliopsis philippiana, tratamiento térmico, tableros de partículas. ABSTRACTThe purpose of this work was to determine the effect of a thermal treatment in a vapor water saturated atmosphere, on wood particles of Laureliopsis philippiana. The particles in autoclave at 150 ºC for 90 minutes and with a pressure of 430 kPa were thermally treated, the pressure generated by the evaporation of water in the sealed autoclave. The amount of extractives in soda, ethanol-toluene, cold and hot water, as well as, the percentages of cellulose, holocellulose and lignin, the pH value, the percentages of volatiles and washables acids, and buffer capacity, for both particles without and with treatment, were determined. In thermally treated particles an increase in the percentage of extractives, cellulose and volatiles and water soluble acids was found, as well as, in thermally treated particles an increment of acidity and a higher buffer capacity was found, in comparison with the particles without treatment. The thermal treatment produced a color change in the particles and a reduction in their wettability. Due to the chemical changes found in the treated particles they could present advantages in the particleboard production, allowing a better ureaformaldehyde polymerization.

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“…According to the ΔE* analysis, the samples treated at the lower temperatures (i.e., 170 and 190 °C) had ΔE* < 10, indicating no evident color changes, which was mainly attributable to the structural alteration of the polar extractives in the wood (Yao et al 2012). The ΔE* of the samples implied that the treatment duration had a moderate effect on the surface color change.…”

Section: Surface Propertiesmentioning

confidence: 99%

“…The heat treatment also promoted the optical absorption and color formation behaviors of the wood (Yamauchi et al 2005;Windeisen and Wegener 2008;Yao et al 2012). During the heat treatment process, the degradation of hemicelluloses released organic acids, which facilitated polysaccharide degradation (Sivonen et al 2002).…”

Section: Surface Propertiesmentioning

confidence: 99%

“…The samples treated at 170 °C had relatively high b* values, which could be attributed to the phenols on the wood surface turning into a grayish yellow color as a result of the low-temperature heat treatment (Yao et al 2012). The color parameters (i.e., L*, a*, and b*) of the samples treated at temperatures greater than 190 °C had higher values because of chemical changes of wood components (Sundqvist and Morén 2002).…”

Section: Surface Propertiesmentioning

confidence: 99%

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Effects of Temperature and Duration of Heat Treatment on the Physical, Surface, and Mechanical Properties of Japanese Cedar Wood

Yang¹,

Chang²,

Lin³

et al. 2016

BioResources

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This study investigated the application of heat to wood samples from Japanese cedar trees (Cryptomeria japonica) of small and medium diameters to evaluate the effects of both the temperature and duration of treatment on its surface, physical, and mechanical properties. The results indicate that the density, moisture content, and hygroscopicity of the wood samples decreased as the treatment temperature and duration increased, and the mass loss increased under the same conditions. Additionally, the dimensional stability of the wood improved in response to increased temperatures and prolonged durations. These results suggest that heat treatment can be used to improve the dimensional stability of wood. The surface color of the wood darkened progressively with increasing treatment temperature and duration, and the hydrophobicity of the wood sample improved as a result of the heat treatment. In contrast to the untreated wood, the heat-treated wood exhibited decreased mechanical properties with an increase in the treatment temperature and duration.

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Coloring characteristics of in situ lignin during heat treatment

Cited by 63 publications

References 16 publications

Surface photo-discoloration and degradation of dyed wood veneer exposed to different wavelengths of artificial light

Surface photo-discoloration and degradation of dyed wood veneer exposed to different wavelengths of artificial light

Propiedades químicas, color y humectabilidad de partículas de Laureliopsis philippiana (tepa) con y sin tratamiento térmico

Effects of Temperature and Duration of Heat Treatment on the Physical, Surface, and Mechanical Properties of Japanese Cedar Wood

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