Treesearch

The development of new and improved wood adhesives is hindered by an incomplete mechanistic understanding of what makes a wood–adhesive bond able to withstand changes in moisture levels. Although common methods are established to test and report the bulk-level properties of bond lines, such as bond-line shear strength and wood failure analysis, the development of experimental tools to study wood–adhesive bond lines and the effects of moisture at the nanometer to millimeter length scales remains an active area of research. Here we introduce and briefly review four recently developed tools...

Cellulose nanocrystal (CNCs)-reinforced poly(lactic acid) (PLA) nanocomposites were prepared using twin screw extrusion followed by injection molding. Masterbatch approach was used to achieve more efficient dispersion of CNCs in PLA matrix. Modified CNCs (b-CNCs) were prepared using benzoic acid as a nontoxic material through a green esterification method in a solvent-free technique. Transmission electron microscopy images did not exhibit significant differences in the structure of b-CNCs as compared with unmodified CNCs. However, a reduction of 6.6–15.5% in the aspect ratio of b-CNCs was...

This paper evaluates the potential of using 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose nanoparticles (T-CNPs) as additives to tune the rheology of water-based acrylic resin (AR) coatings for flexible packaging applications. Three T-CNPs of T-CNF, T-MCC, and T-CNC were prepared from three starting cellulosic materials: cellulose nanofibers (CNF), microcrystalline cellulose (MCC), and cellulose nanocrystals (CNC), respectively. Their sizes ranged from 20 nm to 20 lmin diameter, and 234 nm to over 500 nm in length. The oxidation imparted carboxyl groups on the surfaces...

This study quantifies the cost of cellulosic sugar production using a fully-mechanical pretreatment process and fuel pellets as a co-product. The pretreatment reduces softwood forest harvest residuals to micron-sized amorphous particles. Energy consumption is minimized using a three-stage milling process. A techno-economic analysis was completed for a milling facility with saccharification and wood pellet manufacture. For the base case, concentrated sugar syrup can be produced for $0.496/kg of sugar. Sensitivity analyses were used to determine cost controlling variables, optimize the sugar...

Catalytic graphitization of kraft lignin to nano-materials was investigated over four transitional metal catalysts (Ni, Cu, Fe, and Mo) through a thermal treatment process under an argon flow at 1000 °C. The catalytic thermal process was examined using thermal gravimetric analysis (TGA) and temperature-programmed decomposition (TPD) experiments. The crystal structure and morphology of the thermal-treated metal-lignin samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy....

Modifying bio-based degradable polymers such as polylactide (PLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with non-degradable agents will compromise the 100% degradability of their resultant composites. This work developed a facile and solvent-free route in order to fabricate 100% bio-based and degradable ternary cellulose/PHBV/PLA composite materials. The effects of ball milling on the physicochemical properties of pulp cellulose fbers, and the ball-milled cellulose particles on the morphology and mechanical properties of PHBV/PLA blends, were investigated experimentally and...

Pulper consistency affects production capacity, defibering efficiency, and particle size distribution of contaminants, and in particular, stickies and inks. The effect of pulper consistency on stickies size distribution, though important, has not been studied in detail. In this project, pressure-sensitive adhesive (PSA)-containing furnish was pulped in a laboratory at 5%, 10% and 15% consistency. Results show that 15% consistency pulp produced many more small-sized stickies compared to pulps produced at 5% and 10% consistency. This is contrary to the generally accepted hypothesis and needs...

This study evaluated the potential of an acid hydrotropic process at low temperatures for on-farm valorization of wheat straw by producing ligocellulosic nanofibrils (LCNFs), lignin nanoparticles (LNPs), and furfural. p-Toluenesulfonic acid (p-TsOH) was used to fractionate wheat straw under a range of conditions below 90 °C at low to moderate concentrations, between 15 and 60 wt %, for up to 2 h. p-TsOH fractionated wheat straw into a cellulose-rich waterinsoluble solid (WIS) fraction and a spent liquor stream that contained dissolved lignin and xylan. Various degrees of delignification...

Stable and durable wood products can be produced by chemical modification at the molecular level. One modification that is effective in achieving these properties is by reacting both hardwoods and softwoods with acetic anhydride. The reaction takes place in the most accessible hydroxyl groups in the cell wall polymers. Lignin reacts the fastest followed by the hemicelluloses. Both are highly substituted. As the level of bonded acetyl increases, dimensional stability increases and attack by fungi decreases. The threshold of fungal resistance is approximately 18% acetyl. The moisture in the...

Kraft lignin was catalytically graphitized to graphene-based nanostructures at 1000 C under argon atmosphere with four iron catalysts, iron(III) nitrate (Fe-N); iron(II) chloride (Fe-Cl2); iron(III) chloride (Fe-Cl3); and iron(II) sulfate (Fe-S). The catalytic decomposition process of iron-promoted lignin materials was examined using thermalgravimetric analysis and temperature-programmed decomposition methods. The crystal structure, morphology and surface area of produced materials were characterized by means of X-ray diffraction, Raman, scanning electronmicroscopy, high resolution...