Accelerated Weathering of Coated and Uncoated Beech Wood Modified with Citric Acid

Changes in chemical composition of decayed Scots pine and beech wood

“…As can be seen from Table 1, changes in peak intensities of aged Scots pine were supposed to be related to some modifications in hemicellulose and cellulose after aging treatments. Heat applications and weathering factors (UV and rain) generally cause a decrease at Brought to you by | Carleton University OCUL Authenticated Download Date | 6/21/15 9:20 PM the intensity of 1730 cm -1 peak probably due to cleavage of acetyl groups [39][40][41] and leaching of functional groups [42,43]. The small decrease of the water peak at 1650 cm -1 for pine samples might be related to the decrease of the carbonyl peak [40].…”

“…Heat applications and weathering factors (UV and rain) generally cause a decrease at Brought to you by | Carleton University OCUL Authenticated Download Date | 6/21/15 9:20 PM the intensity of 1730 cm -1 peak probably due to cleavage of acetyl groups [39][40][41] and leaching of functional groups [42,43]. The small decrease of the water peak at 1650 cm -1 for pine samples might be related to the decrease of the carbonyl peak [40]. The small decrease at 1370 cm -1 peak for aged Scots pine and at 1027 cm -1 peak of aged beech samples was related to the CH 2 bending in cellulose and hemicellulose and C-O stretching in cellulose and hemicellulose, respectively.…”

Abiotic and biotic degradation of post-consumer polypropylene/ethylene vinyl acetate: Wood flour composites exposed to natural weathering

“…The presence of catalyst residues, hydroperoxide groups, and carbonyl groups introduced during polymer manufacturing, processing, and storage accounts for this similarity . Photo‐degradation causes changes in all scales of polymer dimension, including the monomer unit (oxidation), the chain (crosslinking or chain scission), the morphology (breakdown of tie molecules and crystal), and on the macroscopic scale . Diffusion of oxygen in the polymer controls polyolefin photo‐degradation .…”

“…Photo‐degradation causes changes in all scales of polymer dimension, including the monomer unit (oxidation), the chain (crosslinking or chain scission), the morphology (breakdown of tie molecules and crystal), and on the macroscopic scale . Diffusion of oxygen in the polymer controls polyolefin photo‐degradation . Density gradients due to oxidation gradients cause the stresses, which combined with chain scission, could initiate and propagate cracks.…”

Evaluation of Wood Resistance to Artificial Weathering Factors Using Compressive Properties

“…These methods differ between themselves in order and intensity of effects of individual factors (eg. Temiz et al, 2007;Evans et al, 2008;Follrich et al, 2011;Miklečić and Jirouš-Rajković, 2011). In addition, the fact should be taken into account that the size of samples used to determine the mechanical properties of artifi cially weathered wood is unrestricted, one published study -right for a type of test samples and artifi cial weathering -cannot be directly related to the results obtained in other trials.…”