Research Articles

The chemical components of essential oil of Toona sinensis leaf blades and their petioles from China were extracted by simultaneous distillation solvent extraction (SDE) and were analyzed by GC-MS. The antimicrobial and DPPH scavenging activity of the essential oil were evaluated. The results showed that there were differences in chemical compositions and content among essential oils extracted from T. sinensis in different parts and different geographical areas in China, but the main components of essential oils were sesquiterpene and sesquiterpene oxygenated compounds, accounting for 90.1% (No. 1), 92.6% (No. 2), and 80.9% (No. 3) of the relative mass fraction, respectively. T. sinensis essential oil exhibited noticeable growth inhibitory activity against the tested microorganisms. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of different essential oils against microorganisms were different. For all essential oil samples, MIC and MBC against Escherichia coli and Bacillus subtiliswere less than 25 μg·mL−1, MIC and MBC against Penicillium citrinum were 200 and 400 μg·mL−1, respectively, and MIC and MBC against Colletotrichum gloeosporioides were 50 and 200 μg·mL−1, respectively. The IM50 of DPPH scavenging for T. sinensis essential oil was less than 0.3 g DPPH per g essential oil. The results indicated that T. sinensis essential oil may be a useful natural antiseptic source from forest products.

A type of conductive graphite/cellulose composite film used for chemical vapor-sensing material was prepared at room temperature in the ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIm]Cl). Graphite was pretreated with both oxidation and reduction processes. Due to the use of N,N-carbonyldiimidazole (CDI), as a covalent cross-linking agent in [BMIm]Cl, there were limited chemical bonds between the graphite and cellulose. The composite film was analyzed using Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and X-ray photoelectron spectroscopy (XRD). When these conducting films were exposed to certain organic vapors, their electrical resistances quickly changed, showing gas sensitivity. The percolation threshold of the conducting film was about 5 wt%. The gas-sensing behavior of these films in solvent were the opposite of those gas-sensing materials based on a non-polar polymer matrix. A typical negative vapor coefficient (NVC) was observed when the film was placed in polar organic solvents such as methanol, ethanol, and acetone.

In this study, the effects of chemical modifications of oil palm mesocarp fiber (OPMF) via bleaching, silane coupling agents, and combinations of the two on the composition and morphology of OPMF were investigated. The chemically modified OPMF was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The FTIR spectra showed that bleached OPMF became more hydrophilic, while silanized unbleached and silanized bleached OPMF became less hydrophilic. The TGA thermograms indicated that bleaching successfully removed hemicellulose from the OPMF, while TGA analysis showed that silanized unbleached and silanized bleached OPMF had higher thermal stabilities than unbleached or bleached OPMF. The SEM micrographs revealed that the modified OPMF surface was rougher and more porous than that of the unbleached OPMF, further indicating that OPMF was successfully modified.

Chemical modification of wood with the aim of improving its dimensional stability can also influence the mechanical behavior of the timber when assembled into a structure. Hence, in this study, the stress-carrying capacity of mitred and butted L-type joints constructed from furfurylated wood samples with two weight percentage gains (WPGs), i.e., 20 and 60% (low and high levels, respectively), was investigated by subjecting the specimen to a diagonal tension load. Results indicated that the bending moment resistance of both L-type joints depends on the WPG. The L-type joints’ bonded stress value with poly-vinyl acetate (PVAc) adhesive decreased with increasing WPGs. Likewise, in the case where epoxy adhesive was used for jointing, the stress capacity increased for both joints constructed with furfurylated wood. Values of tension stress in the butted joint were higher compared to the mitred one. Evaluation of shear stress parallel (׀׀ ) and perpendicular () to the grain of members jointed with PVAc adhesive demonstrated that the shear stress-carrying capacity decreases as furfurylation level increases. However, by applying epoxy adhesive for jointing, τ׀׀ and τ┴ were increased by raising the furfurylation levels.

Pineapple agro-waste, the residue produced during harvesting or processing activities, is widely available around the world. After harvesting, most pineapple residue is disposed of and serves as fertilizer, or is burnt in an open field. However, these methods are not only ineffective, but also contribute to air pollution. The main objective of this study is to determine the physicochemical properties (i.e., cellulose, hemicellulose, lignin, proximate composition, dry matter, and nitrogen content), of leaves and stems in different varieties (MD2, Moris, and Josapine) of the pineapple plant waste. The data obtained were analyzed using thermogravimetry analysis and proximate analysis. The results showed that the stems and leaves of different varieties exhibit different percentages in lignocellulosic content (hemicellulose, cellulose, and lignin). Proximate analysis showed that nutrient contents were available in the leaves and stems of pineapple plant of different varieties.

Palm kernel cake (PKC), a by-product of palm oil industry, contains glucose and mannose as hexose sugars. This study was performed to determine the feasibility of using PKC as a lignocellulosic substrate for biobutanol production by Clostridium saccharoperbutylacetonicum N1-4 in an acetone-butanol-ethanol (ABE) fermentation process. Moreover, the effect of tryptone-yeast extract-acetate (TYA) medium and P2 medium on biobutanol production was evaluated. Experimental results showed that butanol production of 3.05 g/L was obtained using mannose sugar, which was comparable to 3.61 g/L butanol production measured using glucose. Moreover, the maximum production of biobutanol (0.38 g/L) was obtained at a PKC concentration of 30%, indicating the possibility of PKC utilization in butanol production. ABE fermentation of PKC using distilled water, TYA medium, and P2 medium showed that the highest butanol production (0.26 g/L) with ABE production of 0.38 g/L was obtained when ABE fermentation was conducted in P2 medium.

The aim of the paper was to examine the application of regenerated cellulose fibers as a reinforcement material in particleboard production. Single-layer, 10 mm thick panels, with the density of 800 kg/m3 were produced with addition of regenerated cellulose fibers in the range of 0 do 15% by mass during panels’ production. The mechanical and physical parameters of the produced panels were tested, as well as work of fracture. The results showed that addition of regenerated cellulose fibers to the structure of wood-based composite did not improve their modulus of rupture, modulus of elasticity, or internal bond. The physical parameters of the produced panels (water absorptivity, swelling in thickness when soaking) also were reduced. The work of fracture of the tested panels increased with increasing content of regenerated cellulose fibers. A strong linear regression between work of fracture and regenerated cellulose fibers content was observed.

Several properties of wood including the cutting power requirements can be correlated to wood density. Therefore, according to the literature, the cutting power requirements (and/or cutting forces) could be computed as a function of the wood specific gravity. This research shows that such an approach, based solely on specific gravity, may be considered a rather rough and imperfect estimate of cutting power. Samples of Scots pine (Pinus sylvestris L.) wood from different provinces in Poland with varying densities were machined on a sash gang saw. The average cutting force versus average wood density (estimated with the standard gravimetric method) was calculated, and the local cutting forces correlated to the local wood density. The average values of the cutting forces measured at selected points along the sample’s length were calculated by linear regression to the X-ray absorbance (density) estimated by means of X-ray radiography.

This study was conducted to evaluate the effects of bio-oil incorporation on properties of bio-oil-phenol formaldehyde (BPF) resol resins along with the optimization of petro-phenol substitution level. Crude bio-oil prepared from endocarp shells of Ziziphus mauritiana by direct solvolytic liquefaction (ethanol-water 1:1 wt./wt. at 300 °C) was used to partially substitute the petro-phenol (30% to 75% wt./wt.) in the resin synthesis. The modified resins were subjected to measurement of various properties, including molecular weight, pH, viscosity, density, gel/cure time, non-volatile solid content, and limiting oxygen index. Bonding performance of the BPF resins was evaluated by measuring the mechanical and hygroscopic properties of the particle boards developed using such resins. With the incorporation of bio-oil, the viscosity and molecular weight of the BPF resins increased, while the values of pH, density, non-volatile solid content, and limiting oxygen index decreased. The gel, cure, and bonding tests revealed that with the addition of more than 45% bio-oil, the gel/cure times of the BPF resins increased, while the bonding performance decreased. Petro-phenol could therefore be substituted by crude bio-oil up to 45% wt./wt. safely.

Financial, environmental, and supply chain analyses of empty fruit bunch (EFB) biomass are needed for the development of a sustainable green chemicals industry in Malaysia. Herein, holistic analysis of the supply system and EFB life cycle cradle-to-gate are analyzed in an effort to make recommendations for the commercial-scale collection and delivery of EFB from crude palm oil (CPO) extraction facilities to biorefineries in Malaysia. Supply chain modeling tracked inputs and outputs for financial analysis. The openLCA software was used for life cycle assessment (LCA). Allocation scenarios were used to explore the impact of accounting methodologies on the competitiveness of EFB compared to other feedstocks. Sensitivity analysis on the effect of transportation distance, emission flows, and allocation methods on resulting environmental impacts were conducted. The No Burden, Economic, and Mass allocation scenarios resulted in 17, -2.3, and -265 kg CO2-eq. BD tonne-1 EFB global warming impacts (GW), respectively. Delivered cost for EFB was calculated to be approximately 45 US$ BD tonne-1. Environmental burdens were sensitive to allocation scenario, covered area, and land use change. Delivered cost was sensitive to transport distance, covered area, and yield. It was shown that there is sufficient Malaysia EFB available for between 9 and 28 biorefineries, depending upon the scale of production.