Treesearch

Since the mid-19th century, rare prehistoric wooden carvings and human skeletal remains have been dredged from Pitch Lake, Trinidad, during commercial asphalt mining. Establishing a chronology for these objects is challenging, due to both a lack of stratigraphic and contextual information and the necessity to completely remove any pitch to ensure accurate radiocarbon (14C) dates. A range of solvent extraction protocols was tested to identify the most suitable one for pretreating the Pitch Lake artifacts, and then applied to ten wooden objects and a human cranium recovered from the lake....

The production of renewable chemicals and biofuels must be cost- and performance- competitive with petroleumderived equivalents to be widely accepted by markets and society. We propose a biomass conversion strategy that maximizes the conversion of lignocellulosic biomass (up to 80% of the biomass to useful products) into high-value products that can be commercialized, providing the opportunity for successful translation to an economically viable commercial process. Our fractionation method preserves the value of all three primary components: (i) cellulose, which is converted into dissolving...

To keep environmental product declarations current, the underlying life-cycle inventory (LCI) data and subsequent life-cycle assessment data for structural wood products must be updated. Primary data collected from the industry for the year 2012 were analyzed using the weighted-average to update LCIs for laminated veneer lumber (LVL) production on a 1-m3 basis in the Southeast (SE) and Pacific Northwest (PNW) regions of the United States. In addition, cradle-to-gate life-cycle impact assessments (LCIAs) were performed to assess the environmental impacts associated with LVL production for...

Transparency of environmental impacts for building products is of increasing concern. For wood building products, updating life-cycle assessment (LCA) data are critical to ensure that the corresponding environmental product declarations are of the proper recency to maintain this transparency. This study focused on the developing up-to-date life-cycle inventory (LCI) and associated life-cycle impact assessment (LCIA) data for composite I-joist production in the Southeast (SE) and Pacific Northwest (PNW) regions of the United States. Components of the I-joist production system included in...

Cross-laminated timber (CLT) is an emerging product in the North American mass timber market. Intended to compete with pre-cast concrete panels for modular construction, these laminated wall and floor-sized panels have been successfully used in European construction markets for the past 20 years. However, introduction of this material to areas of North America that have high pressure from subterranean termite and decay fungi may prove detrimental to the potential market for this product. This paper describes ongoing work seeking to describe interactions between CLT with both native and...

Wood-based products can be a sustainable and more environmentally friendly alternative to traditional construction materials because of their reduced contribution to air and water pollution. An integral component of these products is often an adhesive. Because wood is hygroscopic, moisture-induced swelling in the cell walls near the wood– adhesive bondlines can lead to durability and performance issues. Unfortunately, researchers working towards improving the moisture durability of forest products are hindered by an incomplete understanding of the nanoscale mechanisms that contribute to...

Understanding and controlling water in wood is critical to both improving forest products moisture durability and developing new sustainable forest products-based technologies. While wood is known to be hygroscopic, there is still a lack of understanding of the nanoscale wood-water interactions necessary for increased moisture-durability and dimensional stability. My PhD thesis focuses on the development and implementation of neutron scattering methods that can provide insight on both the structural and dynamical changes associated with these interactions so that products with improved...

The status of pilot-scale production methods for cellulose nanorods or nanocrystals and the 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-0xyl (TEMPO) grade of cellu— lose nanofibrils are discussed. Both products appear to be poised for scale-up when markets develop, but there are a number of issues that need to be addressed. This chapter outlines concepts for conversion to continuous processes and other issues and concerns that need to be resolved for investments in commercial-scale pro- duction facilities. For large-scale production of cellulose nanocrystals, topic items include site...

Cellulose nanocrystals (CNCs) are renewable and sustainable filler for polymeric nanocomposites. However, their high hydrophilicity limits their use with hydrophobic polymer for composite materials. In this study, freeze-dried CNCs were modified by transesterification with canola oil fatty acid methyl ester to reduce the hydrophilicity. The transesterified CNCs (CNCFE) were compounded with PLA into nanocomposites. CNCFE with long-chain hydrocarbons plays a role as plasticizer. Increasing CNCFE loadings resulted in clear plasticizing effects. Lower Tg and Tm were achieved for CNCFE-based...

Cellulosic nanofibrils (CNFs) were isolated from one of the most widespread freshwater macroalgae, Aegagropila linnaei. The algae were first carboxylated with a recyclable dicarboxylic acid, which facilitated deconstruction into CNFs via microfluidization while preserving the protein component. For comparison, cellulosic fibrils were also isolated by chemical treatment of the algae with sodium chlorite. Compared with the energy demanded for deconstruction of wood fibers, algal biomass required substantially lower levels. Nevertheless, the resultant nanofibrils were more crystalline...