Effect of dimethylol dihidroxy ethylene urea resinmodification on physical and mechanical properties ofparallel strand lumber made from poplar

Due to increasing environmental pressures in many parts of the world, studies on increasing the use of wood material by using environmentally friendly methods have become more important. Recent trends in the wood preservation industry is the usage of environmental friendly wood protection methods including Dimethylol dihidroxy ethylen eurea (DMDHEU). Dimethyloldihydroxyethyleneurea (DMDHEU), used to provide wrinkle-free and dimensional stability in the textile industry, has gained commercial success in the forest industry. But, modification with this chemical as well as physical and mechanical properties of parallel strand lumbers (PSL) has not been investigated yet. The aim of this study is to investigate the physical and mechanical properties of PSL by using pressure and temperature with melamine formaldehyde glue after modifying strands from fast growing hybrid poplar wood (I-77/51) (Populus deltoides) with DMDHEU resin. The best results were obtained in 5% wt. DMDHEU modificaiton caused increase in some physical properties but decrease in mechanical properties. The findings of this study may provide information to increase the use of DMDHEU in different wood based composites. Keywords: Poplar, Dimethyloldihidroxyethyleneurea (DMDHEU), melamine formaldehyde, parallel strand lumber, chemical modification.