Volume 8 Issue 2

Fully biodegradable composite materials were obtained through reinforcement of a commercially available thermoplastic starch (TPS) matrix with rapeseed fibers (RSF). The influence of reinforcement content on the water sorption capacity, as well as thermal and thermo-mechanical properties of composites were evaluated. Even though the hydrophilic character of natural fibers tends to favor the absorption of water, results demonstrated that the incorporation of RSF did not have a significant effect on the water uptake of the composites. DSC experiments showed that fibers restricted the mobility of the starch macromolecules from the TPS matrix, hence reducing their capacity to crystallize. The viscoelastic behaviour of TPS was also affected, and reinforced materials presented lower viscous deformation and recovery capacity. In addition, the elasticity of materials was considerably diminished when increasing fiber content, as evidenced in the TMA and DMTA measurements.

The use of the aquatic plant cattail to produce an adsorbent for heavy metals will add value to wetlands. Cattail adsorbents were treated with multi-valent carboxylic acids to facilitate adsorption of Pb(II) from a vanillin solution. Fourier transform infrared (FTIR) spectroscopic analysis confirmed the formation of acid modifications by esterification. While unmodified cattail had a Pb(II) adsorption capacity of 3.21 mg/g, citric acid-, malic acid-, tartaric acid-, oxalic acid-, and iminodiacetic acid-modified cattail absorbents were able to adsorb 66.10, 55.42, 44.53, 52.32, and 36.82 mg/g, respectively, at the optimum pH of 4.9. The Pb(II) adsorption capacity increased as the concentration of Pb(II) increased without loss of vanillin during the adsorption process. Desorption of Pb(II) and regeneration of the adsorbents was achieved by 0.1 M HCl elution, which showed that the cattail adsorbents were regenerated easily and could be used repeatedly. The results suggest that acid-modified cattail biomass may be a promising adsorbent for heavy metal ion uptake in water-based cosmetics.

As interest in lignocellulosic biomass as a feedstock for conversion into biofuels is steadily growing, analysis of its components becomes ever more important. The complete chemical composition of waste hemp hurds from the industrial variety “Carmagnola” has been determined to optimize its utilization as a raw material. The results from chemical analysis show that hemp hurds contain 44.0% alpha-cellulose, 25.0% hemicellulose, and 23.0% lignin as major components, along with 4.0% extractives (oil, proteins, amino acids, pectin) and 1.2% ash. Structural and physicochemical properties of hurds components were analysed by FTIR or GC/MS. The data revealed that isolated components are pure and comparable to standard components. Acetone extractives show higher total phenolic content and antioxidant capacity compared with lignin and dichloromethane extractives. Water extractive shows the presence of proteins (1.6%), free amino acids (0.02%), and pectin (0.6%). The degree of esterification of pectin was estimated to be 46.0% by FTIR and enzymatic hydrolysis. The results of this study show that Carmagnola hurds contain low amounts of ash and high amounts of carbohydrates compared with other varieties of hemp hurds; therefore they can be considered as a potential feedstock for biorefinery.

The main challenge in the oxygen delignification process is the improvement of selectivity. To further understand the effect of the amount of hydroxyl radicals on the selectivity of oxygen delignification, in this work, the hydroxyl radicals were generated by the improved Fenton reaction system and were quantified by UV spectrophotometry. Antioxidants such as ascorbic acid were applied for the scavenging of hydroxyl radicals so that the amount of hydroxyl radicals could be regulated. The bamboo kraft pulps were treated with the Fenton system or the Fenton system combined with ascorbic acid. The results indicated that the improved Fenton reaction system could be used for the determination of hydroxyl radicals by UV spectrophotometry. The amount of hydroxyl radicals could be regulated to a suitable extent by the hydroxyl radical scavengers during oxygen delignification so that the delignification selectivity improvement was achieved.

As many larger secondary woodworking firms have moved production offshore and been adversely impacted by the recent housing downturn, smaller firms have become important to driving U.S. hardwood demand. This study compared and contrasted small and large firms on a number of factors to help determine the unique characteristics of small firms and to provide insights into useful areas for support. Small firms were found to be similar to large firms with respect to the perceived importance attributed to manufacturing capabilities as a business success factor. However, small firms differed substantially from large firms in other ways, such as less attention to information seeking and planned investments. Small firms also tended to make greater use of distribution yards in the hardwood lumber purchasing value chain and requested fewer services from their hardwood lumber suppliers than did larger firms. Small firms were found to be keen on developing their marketing capabilities, including e-commerce, to further their information exchange with customers to successfully produce made-to-order products. Small firms considered the individual characteristics of company owners/managers to be a relatively important success factor to business, more so than larger firms. The results are summarized and discussed through the lens of small firm reliance on niche markets for survival (including fully made-to-order production) and their need to find new revenue during economic downturns.

In this paper, four different nondestructive testing (NDT) methods and static bending tests were done on poplar (Populus ussuriensis Kom.) and birch (Betula platyphylla Suk.) Laminated Veneer Lumber (LVL). The effects of compression ratio on the modulus of elasticity (MOE) and modulus of rupture (MOR) of LVL with vertical load and parallel load were investigated. There were four compression ratios: 8.1%, 18.3%, 26.5%, and 33.1%. The microscopic structure of LVL was analyzed with a scanning electron microscope (SEM). Results showed a strong correlation between each dynamic Young’s modulus and the static MORof LVL; the MOE and MOR of LVL changed with the increase of compression ratio. MOE and MOR were greatly increased when the compression ratio increased from 18.3% to 26.5%, and the microstructure of LVL changed greatly between different compression ratios by birch and poplar species.

The combustion and emission characteristics of ethyl­ levulinate (EL)–diesel blended fuels were investigated using engine bench tests. Blended fuels properties, including the kinematic viscosity (KV), density, EL proportions, oxygen content, cetane number (CN), and lower heating value (LHV) were considered. The combustion and emission characteristics of brake-specific fuel consumption (BSFC), as well as hydrocarbon (HC), nitrogen oxide (NOx), carbon monoxide (CO), and carbon dioxide (CO2) emissions, as well as smoke opacity, were tested. The relationship between the blended fuel properties and the combustion–emission characteristics were analyzed using grey relational analysis (GRA). The correlation degree between the fuel properties and the combustion–emission results indicated that the BSFC was influenced most by the density of the blended fuels. NOx, CO, and CO2 emissions were influenced most by the oxygen content. The KV was the most influential parameter for HC emissions and the opacity of the blended fuels. The oxygen content was the foremost influential parameter. The results show that GRA could be used to increase the comprehensiveness of combustion–emission blended-fuel studies, by providing a reference for the reasonable use of biofuel-diesel mixtures.

The kinetics of the reaction of cotton linter pulp with acetic anhydride catalyzed by sulfuric acid at temperatures ranging from 30 to 45 °C have been investigated. A kinetic model considering the dissolution of the sufficiently sulfated cellulose chains on the surface of the solid fibers, and the subsequent reactions in the liquid phase was proposed for the acetylation process. The kinetic parameters were regressed from the measured degree of substitution using a nonlinear regression method. With the optimum values of the rate constants, the proposed model can predict the acetylation process very well. The chemical activation energy of the reactions of the cellulose hydroxyl groups with acetic anhydride was estimated as 39.6 kJ/mol. The dissolution rate of the sulfated chains can be represented by the equation r/r0=1-kt. A similar equation, the Arrhenius expression, k=Aexp(-E/RT) was used to predict the dissolution rate constants. The corresponding activation energy for the dissolution was evaluated as 19.6 kJ/mol.

In this study fiber cell wall porosity was altered by fiber line simulation in a laboratory. The changes in the fiber cell porosity were analyzed with a water retention value (WRV) test. Pore size distributions were measured by differential scanning calorimetry (DCS), and atomic force microscopy (AFM) was used to determine the cell wall pore area from cross sections of the S2 layer of the cell wall. WRV was shown to correlate with the amount of water in the pores with a diameter of at least 200 nm. Changes in the non-freezing and total bound water did not affect the WRV. The calculated shrinkage forces generated by the capillary forces in different pore cell wall structures correlated with the sheet densities generated by fiber networks. It was observed that the swelling of the cell wall, defined as an increase in the diameter of the cell wall, was most likely not occurring or was very difficult to detect.

Moringa oleifera seeds were investigated for the removal of manganese ions from aqueous solutions. The seeds utilized were obtained from plants grown in Uberlândia, Brazil. After being dried and pulverized, the seeds were treated with 0.1 mol L-1 NaOH. Using the optimized methodology (50 mL of 4.0 mg L-1 Mn(II), pH range of 4.0–6.0, contact time of 5 min, and biosorbent mass of 0.5 g) it was found that 100% of Mn(II) could be removed from water samples. In order to remove up to 95% of Mn ions in 50 mL of a laboratory residue produced during biochemical oxygen demand determinations with 112.0 mg L-1 of manganese, the contact time and pH were maintained, but a mass of 3.0 g was used. The kinetic data were fitted to a pseudo-second-order kinetic model. The sorption data were fitted satisfactorily to the Langmuir and Freundlich isotherm models. Evaluation applying the Langmuir equation gave the monolayer sorption capacity as 5.61 mg/g. In this application the method was found to be efficient, fast, simple, and economical.