Synthetic adhesives, such as phenol-formaldehyde (PF) resins and urea-formaldehyde (UF) resins, have dominated the wood adhesive market since they were introduced in the wood products industry. Formaldehyde, as a key component in the manufacturing of PF and UF resins, has been classified as a known human carcinogen by the International...
Heartwood can have properties that are distinct from sapwood,
including resistance to insect and microbial attack. Despite the practical
importance of heartwood formation in trees, a review of the literature revealed
that little was known about the effects of environmental factors on heartwood
quality or how variations in heartwood properties...
In wood-plastic composites (WPCs) a compatibilizer is often used to improve
the interfacial adhesion between the hydrophilic wood filler and the hydrophobic
plastic matrix. At present, while the basic concepts of compatibilization are
understood, the optimized chemical structures of an effective compatibilizer, including
the ideal structures of the wood-binding domain...
High density polyethylene (HDPE) is a ubiquitous material with versatile properties. It is produced and used in greater volume than any other thermoplastic. HDPE is often filled with a variety of materials for various applications. Glass fiber and wood flour are two common fillers for HDPE. Recently there has been...
Rubber without reinforcement has limited applications. The strength of reinforced rubber composites can be ten times stronger than that of unreinforced rubbers. Therefore, rubber composites are widely used in various applications ranging from automobile tires to seals, valves, and gaskets because of their excellent mechanical elastic properties. Silica and carbon...
Agroforestry is a traditional farming practice in American Samoa that has helped to sustain the livelihood of the native population for centuries. These once self-sufficient islands have become economically dependent on U.S monies and other external resources during the past century. Dependency has caused a shift in the carrying capacity...
Many herbivores of the Pacific Northwest rely on forest understory shrub leaves for a source of nitrogen, energy, and moisture. I measured nitrogen, protein-binding capacity, and condensed tannin concentration as indicators of available nitrogen; cell wall constituents and lignin as indicators of available energy; and moisture concentration in young and...
There is a continual interest in developing robust, flexible, durable, lightweight, waterborne polymer barrier coatings which are increasingly resistant towards both chemical warfare agents as well as an ever growing number of toxic industrial chemicals. In this study, barrier films were prepared with poly(vinyl alcohol) (PVOH) and varying amounts of...
Western redcedar (Thuja plicata Donn.) is a valuable commercial species found in
the northwestern United States and southwestern Canada. This dissertation includes four
papers focused on wood and stem characteristics of second-growth western redcedar, and
how those characteristics vary within the stem or how they are influenced by cultural
practices....
Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a...