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Study of Physical and Mechanical Properties of Hardened Hybrid Poplar Wood = Étude des propriétés physiques et mécaniques du bois des peupliers hybrides durcis

Ding, Wei Dan (2009). Study of Physical and Mechanical Properties of Hardened Hybrid Poplar Wood = Étude des propriétés physiques et mécaniques du bois des peupliers hybrides durcis. Mémoire. Rouyn-Noranda, Université du Québec en Abitibi-Témiscamingue, Sciences appliquées, 127 p.

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Résumé

Hybrid poplar has been planted widely in North America for its fast-growing, easy hybridization properties. However, due to its inherent characteristics of low density and high moisture content, hybrid poplar is not well-suited for products requiring high strength, surface hardness, or for use in Joad bearing applications. It is considered an important fibre resource for pulp and paper. This study explores the potential of this species through the use of polymer impregnation for wood hardening. Wood samples, from eight hybrid poplar clones, aspen, silver maple, white ash, red oak and northern white cedar, were impregnated with methyl methacrylate (MMA) and polymerized in situ using the heat-catalyst method. Hybrid poplar clones were investigated for the effect of wood hardening on swelling percent in three principle directions, volumetry swelling properties, water uptake, water repellent efficiency and anti-swelling efficiency after soaking, hardness, compression strength, static flexion and abrasion resistance. Monomer impregnation rate and polymer retention rate of the six wood species, and changes in their pore characteristics before and after hardening determined using mercury intrusion porosimetry (MIP) were also studied to evaluate the effects of wood species and density. PMMA occupied mainly pores with diameter d > 0.1 J.Ull in the wood samples. Porosity appears to be the main determinant of impregnation rate and polymer retention, especially for porosity with pore diameter > 0.1 Jlm. Polymer retention was found in the range of 142- 180% for the studied clones, and the densities of the hardened poplar wood samples were 2.2 to 2.6 times higher than control. The presence of polymer significantly decreased volumetry swelling and water uptake by several times. Mechanical test results showed varying increases in static bending, compression strength, hardness for hardened poplar woods. However, the risk of increased brittleness was observed as well. Treated wood also exhibited superior abrasion resistance compared to control samples.

Type de document: Thèse (Mémoire)
Directeur de mémoire/thèse: Koubaa, Ahmed
Informations complémentaires: Mémoire réalisé à l'Université du Québec en Abitibi-Témiscamingue, présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en ingénierie dans le cadre du programme de maîtrise extensionné de l'UQAC à l'UQAT. Comprend des réf. bibliogr. (p. [86]-92).
Mots-clés libres: propriete mecanique bois peuplier hybride durcissement mma methyle methacrylate
Divisions: Sciences appliquées > Maîtrise en ingénierie
Date de dépôt: 19 déc. 2011 18:44
Dernière modification: 21 févr. 2013 20:40
URI: http://depositum.uqat.ca/id/eprint/59

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