Treesearch

This study investigated the inhibition of enzymatic hydrolysis by unbound lignin (soluble and insoluble) with or without the addition of metal compounds. Sulfonated, Organosolv, and Kraft lignin were added in aqueous enzyme-cellulose systems at different concentrations before hydrolysis. The measured substrate enzymatic digestibility (SED) of cellulose was decreased by 15% when SL was added to a concentration of 0.1 g/L due to nonproductive adsorption of enzymes onto lignin. Cu(II) and Fe(III) were found to inhibit enzymatic cellulose hydrolysis in the presence of lignin. Ca(II) and Mg(II)...

Borate penetration relies on diffusion when borate and glycol-borate preservatives are applied to the surface of wood. This study evaluated the extent of borate penetration in framing lumber as a function of preservative formulation, wood moisture content, and diffusion time after treatment. In Phase I of the study, end-matched specimens were conditioned to target average moisture contents of 15, 25, or 35 percent, briefly immersed in borate formulations, and then placed into wooden frames to minimize air exchange during diffusion. Penetration in these specimens was generally less than 5...

Overstocked small-diameter softwood timber in western US forests has created a serious forest health and fire hazard, and the costs of removing this material are high. One way to lower costs is to reduce loss because of warp on lumber sawn from these small logs. Using a green-gluing process, standard 38 by 89-mm (nominal 2 by 4-in.) pieces (2 by 4s) ripped from pressed panels of edge-glued (edge-glued-and-rip [EGAR]) boards sawn from small ponderosa pine (Pinus ponderosa) logs were evaluated for warp reduction. Material was bonded at high moisture content (MC) to simulate lumber freshly...

The performance of two pretreatment methods, sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL) and dilute acid (DA), was compared in pretreating softwood (spruce) for fuel ethanol production at 180ºC for 30 min with a sulfuric acid loading of 5% on oven-dry wood and a 5:1 liquor to-wood ratio. SPORL was supplemented with 9% sodium sulfite (w/w of wood). The recoveries of total saccharides (hexoses and pentoses) were 87.9% (SPORL) and 56.7% (DA), while those of cellulose were 92.5% (SPORL) and 77.7% (DA). The total of known inhibitors (furfural, 5-hydroxymethylfur...

The cell wall of most plant biomass from forest and agricultural resources consists of three major polymers, cellulose, hemicellulose, and lignin. Of these, hemicelluloses have gained increasing attention as sustainable raw materials. In this study, novel pH-sensitive semi-IPN hydrogels based on hemicelluloses and chitosan were prepared using glutaraldehyde as the crosslinking agent. The hemicellulose isolated from aspen was analyzed for sugar content by HPLC, and its molecular weight distribution was determined by high performance size exclusion chromatography. Results revealed that...

Forest biomass conversion to biofuels and other value-added co-products; hyper-performance advanced composites custom tailored to end use requirements; advanced high performance wood-based structures; and nanomaterials and nano-enable high performance products from wood represent important research and development investment areas for the successful transformation of the forest products industry into a reinvented and reinvigorated growth industry in the 21st Century. Research and development investments in the preceding areas will help make wood the sustainable, renewable, and recyclable...

Openness, collaboration and sharing of information in developing the basic underlying, precompetitive science and technology for areas of emerging importance to the forest products sectors of the US and Finland are expected to provide synergistic benefits and allow for more creative problem solving. There appear to be a number of common interests with respect to developing the underlying science and technology needed to reinvent and reinvigorate the Finnish and US forest products industry in the 21st Century.

Vibrational spectroscopy is an important tool in modern chemistry. In the past two decades, thanks to significant improvements in instrumentation and the development of new interpretive tools, it has become increasingly important for studies of lignin. This chapter presents the three important instrumental methods-Raman spectroscopy, infrared (IR) spectroscopy, and near-infrared (NIR) spectroscopy-and summarizes their contributions to analytical, mechanistic and structural studies of lignin. The conceptual frameworks used to interpret vibrational spectra are first described in the following...

Biological systems such as proteins, viruses, and DNA have been most often reported to be used as templates for the synthesis of functional nanomaterials, but the properties of widely available biopolymers, such as cellulose, have been much less exploited for this purpose. Here, we report for the first time that cellulose nanocrystals (CNC) have the capacity to assist in the synthesis of metallic nanoparticle chains. A cationic surfactant, cetyltrimethylammonium bromide (CTAB), was critical to nanoparticle stabilization and CNC surface modification. Silver, gold, copper, and platinum...

Wood-plastic composites represent a growing class of materials used by the residential construction industry and the furniture industry. For some applications in these industries, the fire performance of the material must be known, and in some cases improved. However, the fire performance of wood-plastic composites is not well understood, and there is little information regarding the effectiveness of various fire retardants in the public domain. We used oxygen index and cone calorimeter tests to characterize the fire performance of wood flour-polyethylene composites, and compared the...