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Three different light radiation research photochromic dye veneer

Author: ShaoLingMin
Tutor: LiLi；GuoHongWu
School: Beijing Forestry University
Course: Wood Science and Technology
Keywords: Dyed veneer Xenon light radiation UV radiation FTIR spectra Spectral reflectance curves
CLC: S781
Type: Master's thesis
Year: 2011
Downloads: 40
Quote: 1
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Abstract

In this paper, poplar and birch veneer as test materials, acid red GR and acidic sky blue V is the dye, dyed veneer to prepare for the study, respectively, xenon light, natural light, three kinds of ultraviolet radiation light source aging test , the system analysis of the species, pretreatment, dye structure, dye concentration and irradiation time, and the wavelength of the radiation board photochromic coloring effects and the International Commission on Illumination CIE (1976) L * a * b *. Standard of the dyed veneer photochromic rule. Simultaneously analyzed by electron scanning microscope light deterioration stained veneer on the surface microstructure effects. On this basis, the use of FTIR spectroscopy of light deterioration process dyeing veneer surface chemical changes in the structure and functional groups, combined with spectral reflectance curves and K / S scattered reflectance spectra evaluation dyed veneer lightfastness, the main research results are as follows : a) stained veneer under the action of light radiation are obvious yellowing; species and the concentration of dye stain veneer optically variable was not significant, bleaching pretreatment, type of dye, irradiation time on board photochromic dye significantly affected. Before dyeing the veneer hydrogen peroxide bleaching pretreatment improves the wood dyeing effect, but the bleaching treatment destroys wood component carbonyl, phenolic hydroxyl chemical structure, the stain veneer lightfastness reduce (ΔE * BV0. 5 = 35.9, ΔE * B'V0 .5 = 50.7); acid red GR and acidic sky blue V staining veneer photochromic vary greatly, acidic sky blue V staining veneer photochromic (ΔE * BV1.5 = 41.1) than acid red GR dyeing veneer (ΔE * BGR1.5 = 21.5) .2) stained veneer natural optical radiation through 100d discoloration xenon light radiation law and rules are basically the same color. SPSS analysis results according to the natural light irradiation time (T / d), and xenon light irradiation time (t / h), when the time T = t, satisfy the linear relationship ΔE * N = -1.933 0.876ΔE * X. By scanning electron microscopy analysis of chromatin structure and optical microscopic veneer dyed veneer surface radiation on the impact of micro-structure, the results show that the optical radiation pattern stained veneer surface pore structure destroyed. 3) Five Wavelength 254nm, 313nm, 340nm, 365nm, 420nm of 100h UV light radiation and dyed veneer surfaces are in different degrees of light color, dyed veneer radiation source wavelength is inversely proportional to the degree of discoloration, 254nm ultraviolet radiation photochromic dyed veneer worst. 4) With the radiation time, the spectral reflectance curves downward trend, and ever goes to longer wavelengths, resulting in the red effect, the use of spectral reflectance curves by stained veneer lightfastness is feasible. 5) by FTIR spectroscopy dyed light radiation process of chemical changes in the surface of the board and the light color of the relationship between the optical radiation after dyeing FTIR spectra of the board in 800-1800cm-'fingerprint region generating significant changes in the chemical structure The carbonyl group (absorption peak 1727cm-1) significantly enhanced the absorption intensity of the benzene ring carbon skeleton (1592 cm-1, 1504 cm-1), a phenolic hydroxyl group (1234 cm-1) and the methyl and methylene (1423 cm- 1,1458 cm-1) absorption of a functional group such weakening of lignin under the light radiation gradually degraded. Dyed veneer veneer surface staining and degradation of the chemical structure of the photochromic dye veneer closely related. In summary, this paper on three different stain veneer photochromic optical radiation research, analysis of different factors on the impact of photochromic dye veneer, dyed veneer surface reveals the photochromic process changes the chemical structure, combined with CIE (1976 ) L * a * b * standards, verified dye spectral reflectance curve to evaluate the feasibility of the light resistance board. This study for improving the value of stained wood to expand its scope of application has a certain academic and practical value, and promote the efficient use of plantations.

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