Monitoring Wood Degradation during Weathering by Cellulose Crystallinity

Materials

Francesca Lionetto¹  Roberta Del Sole²  Donato Cannoletta²  Giuseppe Vasapollo² 

[1] Department of Engineering for Innovation, University of Salento, via Monteroni, Lecce 73100, Italy;

关键词: crystallinity;    pine wood;    X-ray diffraction (XRD);    Fourier transform infrared (FT-IR);    outdoor weathering;    wood coatings;    lignin;    cellulose;    wood degradation;   

DOI  :  10.3390/ma5101910

来源: mdpi

【 摘 要 】

The degree of crystallinity of cellulose was used for assessing the degradation level of coated and uncoated samples of pine wood after weathering. X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy measured the changes in the surface crystallinity of cellulose resulting from weathering, both natural and artificial. Both techniques revealed an increase in the crystallinity index (CI) of cellulose when wood was subjected to weathering. An increase in the size of crystallites was also observed by XRD measurements. These results were related to the reduction of the amorphous fractions of wood, and, consequently, to the enrichment of the relative crystalline content. Thanks to FT-IR analysis, the degradation of hemicellulose was observed for uncoated samples after exposure to artificial weathering. The effect of weathering was less evident on coated samples because of the protective action of the coating. A good correlation between the crystallinity indexes obtained from FT-IR and XRD was found. The experimental results proved that the proposed method may be a very useful tool for a rapid and accurate estimation of the degradation level of wood exposed to weathering. This methodology can find application in the field of conservation and restoration of wooden objects or in the industry of wood coatings.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.