首页   按字顺浏览 期刊浏览 卷期浏览 Oxidation of Wood Components During Chromated Copper Arsenate (CCA-C) Fixation
Oxidation of Wood Components During Chromated Copper Arsenate (CCA-C) Fixation

 

作者: MagdyL. Kaldas,   PaulA. Cooper,   Rana Sodhi,  

 

期刊: Journal of Wood Chemistry and Technology  (Taylor Available online 1998)
卷期: Volume 18, issue 1  

页码: 53-67

 

ISSN:0277-3813

 

年代: 1998

 

DOI:10.1080/02773819809350125

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

Pre-extracted radial sections of southern yellow pine sapwood were treated with CCA-C and analyzed by x-ray photoelectron spectroscopy (xps). The ratio of CI (carbon bonded only to carbon and/or hydrogen) to C2 (carbon bonded to one oxygen with a single bond) was used to determine the progress of oxidation of wood components during CCA fixation. This ratio increased after treating times of 10 minutes and 60 minutes and decreased after 180 minutes soaking suggesting that oxidation of C2 predominates on initial contact with CCA solution but oxidation of CI (lignin) becomes more important with extended exposure to the treating solution. Oxidation of C2 to C3 (carbon bonded to two oxygens or a carbonyl group) was demonstrated byin situtrapping of C3 with ethylene glycol as it was formed. Further oxidation of C3 to C4 (carboxylic carbon) was not observed in the xps spectra, consistent with the findings of others. The hypothesis that rapid decarboxylation results in loss of C4 as evolved CO2is supported by the observation that the C4 component of untreated wood was reduced by more than 90% after 10 minutes of CCA soaking followed by high temperature fixation and by the observation of CO2evolution during early stages of accelerated fixation. The Cr(2p) spectra of CrVIand CrIIIwere established at 580.2 and 577.8 eV respectively. Accelerated fixation of CCA-C treated specimens resulted in a very high degree of reduction of CrVIto CrIII. XPS Cu (2p3/2) peaks were established at 935.1 for CCA-C, 935.3 for Cu(OH)2, and 933.7 for CuO. Cu (2p3/2) peaks in CCA-treated wood were shown at 932.9 with no satellite peaks for the 10-60 minutes soaking in CCA series, and at 933.9 and 936.4 with satellite at 941-948 for the 3 hours soaking time. The latter are attributed to complexed copper oxide and hydroxide forms of CuII. Peaks attributed to CuIIhydroxides were shown to diminish in leached samples.

 

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