Performance of beech wood modified with dimethylol dihydroxyethylene urea (DMDHEU) against accelerated weathering

Document Type : Research Paper

Authors

1 Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.

2 Department of Wood Science Engineering, Faculty of Materials Engineering and Interdisciplinary Science, Shahid Rajaee Teacher Training University, Tehran, Iran.

10.22059/jfwp.2024.381075.1309

Abstract

The performance of beech wood modified with methylolated dimethylol dihydroxyethylene urea (mDMDHEU), with low formaldehyde emission, against weathering was investigated. Methylolated dimethylol dihydroxyethylene urea, at a concentration of 30%, and MgCl₂ as a catalyst at 5% by weight were used. After impregnation of the wood samples via the vacuum-pressure process, the samples were cured under superheated steam conditions (100°C for 36 hours) and in an oven (120°C for 24 hours). The weathering resistance of the samples was evaluated under accelerated weathering conditions for 750 hours. The results showed that the weight percent gain (%WPG) was higher in the oven curing method due to the higher treatment temperature; however, the superheated steam curing method showed better performance against weathering. The highest water absorption and swelling occurred in the control sample, while the lowest was observed in the oven-cured sample. The results indicated that the higher treatment temperature led to a further decrease in water absorption and an increase in dimensional stability. FTIR spectroscopy after weathering showed a reduction in the peak of aromatic rings in the modified samples, indicating that lignin was not effectively protected against weathering in any of the treatments. Compared to oven curing, curing with superheated steam resulted in greater water repellency of the surface and reduced changes in color and surface morphology caused by weathering.

Keywords

Main Subjects

References

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Forest and Wood Products
Volume 77, Issue 3
December 2024
Pages 313-326

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