Treesearch

Various instrumental techniques were used to study the fungal decay process in wood plastic composite (WPC) boards. Commercial boards exposed near Hilo, Hawaii (HI) for eight years in both sun and shadow locations were inspected and tested periodically. After eight years of exposure, both boards were evaluated using magnetic resonance imaging (MRI), while a selected area of the board exposed in shadow was additionally tested using microscopy and micro x-ray computed tomography (CT). Experimental boards exposed to either exterior conditions in Vancouver, British Columbia (BC) or a laboratory...

The mechanical properties of Iß crystalline cellulose are studied using molecular dynamics simulation. A model Iß crystal is deformed in the three orthogonal directions at three different strain rates. The stress-strain behaviors for each case are analyzed and then used to calculate mechanical properties. The results show that the elastic modulus, Poisson's ratio, yield stress and strain, and ultimate stress and strain are highly anisotropic. In addition, while the properties that describe the elastic behavior of the material are independent of strain rate, the yield and ultimate properties...

Nanocellulose has enormous potential to provide an important materials platform in numerous product sectors. This study builds on previous work by the same authors in which likely high-volume, low-volume, and novel applications for cellulosic nanomaterials were identified. In particular, this study creates a transparent methodology and estimates the potential annual tonnage requirements for nanocellulose in the previously identified applications in the United States (U.S.). High, average, and low market penetration estimates are provided for each application. Published data sources of...

The moisture and decay resistance of wood-plastic composites (WPCs) reinforced with extracted or delignified wood flour (WF) was investigated. Three different extractions were preformed: toluene/ethanol (TE), acetone/water (AW), and hot water (HW). Delignification (DL) was performed using a sodium chlorite/acetic acid solution. All WPCs specimens were made with 50% by weight HDPE and WF, first compounded using extrusion followed by injection molding. After preconditioning in water at 70 °C for 5 days, the specimens were exposed for 12 weeks to the brown-rot fungus, Gloeophyllum trabeum in...

Nanocellulose provides a new materials platform for the sustainable production of high-performance nano-enabled products in an array of applications. In this paper, potential applications for cellulose nanomaterials are identified as the first step toward estimating market volume. The overall study, presented in two parts, estimates market volume on the basis of estimated tonnage of cellulose nanomaterials rather than the dollar value of production or profits from production. In this paper, we first identified potential uses from literature, presentations, and patent reviews, and then...

Awareness of the environmental footprint of building construction and use has led to increasing interest in green building. Defining a green building is an evolving process with life cycle inventory and life cycle impact assessment (LCIA) emerging as key tools in that evolution and definition process. This study used LCIA to determine the environmental footprint associated with manufacturing 38- ×
138-mm redwood (Sequoia sempervirens) decking from sustainably managed northern California redwood forests. Primary survey data were collected from four redwood mills that represent 90% of...

A fundamental understanding of the morphological development of cellulose fibers during fibrillation using micro grinder is very essential to develop effective strategies for process improvement and to reduce energy consumption. We demonstrated some simple measures for characterizing cellulose fibers fibrillated at different fibrillation times through the grinder. The morphology and degree of fibrillation of the samples at different stages of fibrillation were characterized. The fibrillation and mechanical properties reached a maximum in 2 h, and did not show any significant change with...

Poly(ethylene oxide) (PEO) nanofiber mats were produced by electrospinning. Biobased cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) as reinforcement nanofillers were also added to the polymer to produce composite nanofiber mats. The effects of the two cellulose nanofillers on the rheological properties of the PEO solutions and the microstructure, crystallization, and mechanical properties of the mats were systematically compared. The microstructural disparity between the CNCs and CNFs led to significant differences in the solution viscosity, nanofiber morphology and...

Traditional cellulose nanocrystal (CNC) production methods use harsh chemicals, are energetically expensive, and result in a hydrophilic sulfate surface chemistry with limited utility. Enzymatic production of CNCs is a less expensive alternative production method that eliminates the need for harsh chemicals and requires much less energy for mechanical fibrillation and heating. Furthermore, enzymes that selectively degrade the amorphous regions of cellulose fibers, and do not significantly digest the crystalline areas, result in CNCs that retain a hydroxyl group surface chemistry. Retention...

As early as 1970, the structural engineering and building safety community recognized that a large number of two-, three, and four story woodframe buildings, designed with the first floor used either for parking or commercial space, were built with readily identifiable structural deficiencies, referred to as a “soft story”. Often these buildings also have a strength deficiency when compared to the stories above, in which case they are also classified as “weak”. The majority of these multi-story woodframe buildings have large openings and few partition walls at the ground level. This open...