Volume 10 Issue 4

Depending on the production method, traditional paper mills often utilize the black liquor by burning it for energy. Hemicelluloses extracted from the raw material prior to pulping could be utilized to produce biochemical fuels. The aim of this study was to pre-extract hemicelluloses from wheat straw by treating the biomass with hot water and alkali (NaOH or the combination NaOH+NaBH4) at varying temperatures and chemical concentrations, and also to integrate resulting solid material to produce pulp and to produce bioethanol and biodegradable films from extracted liquor consisting mostly of xylan. Optimum hot water (135 °C) and alkali pre-extractions (16.7% NaOH at 50 °C) removed 16.5% and 33.6% of the xylan from the straw structure, respectively. The liquid portion of the hot water (135 °C) and alkali (16.7% NaOH at 50 °C) pre-extracted oven-dry (OD) straw yielded up to 7.79% and 6.81% (g/100 g soluble material) ethanol. Good-quality biodegradable films were produced when some gluten and nanocellulose was added to the extracted xylan. Although the hot water pre-extracted pulp yield was slightly lower, its physical and mechanical pulp properties were comparable to those of the corresponding conventional soda pulp.

This study demonstrates the preparation, structure, and properties of polymer-impregnated wood (PIW) based on novel Muchelia macclurei wood through the in-situ polymerization of vinyl and functional monomers. Mixed monomers of glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA) (2:1 molar ratio) were effectively vacuum/pressure impregnated into the cellular structure of the fast-growing wood, and then they underwent a catalytic-thermal polymerization process to form a polymer-impregnated wood composite. Scanning electron microscope (SEM) observations showed that the polymer formed from the monomers occupying the cell lumens and formed tight bonds with the wood substrate. Fourier transform infrared (FTIR) microscopy analysis indicated that the in-situ generated polymer probably chemical bonded to the wood cell wall. The resultant PIW exhibited remarkably improved mechanical properties and durability relative to untreated wood. This was attributed to the possible grafting of the polymer onto the wood cell wall and the resultant reinforcement of the wood by the polymer.

The usability of lavender stems along with red pine chips was investigated as raw materials in the production of particleboard. Medium-density particleboard was manufactured using urea formaldehyde glue at three different ratios for five different mixture groups containing lavender stems and red pine chips. Some physical and mechanical properties of the boards were investigated. According to the statistical studies of the results, decreasing the ratio of lavender stems between board groups reduced the thickness swelling value. The internal bond strength, bending strength, and elastic modulus values of all board groups (%10-12 glued) were above the minimum values set by the TS-EN-312 standard for general purpose particleboard. According to these results, either lavender stems alone or together with red pine chips are suitable for use as a new raw material for particleboard manufacturing.

A new controlled release fertilizer was developed by coating urea particles with bio-based polyurethane. Coating materials were synthesized from liquefied wheat straw, isocyanate, and castor oil. The effects of liquefied solvents, mass ratio of liquid to solid, size of wheat straw, and reaction time during liquefaction process on the nitrogen release rate of polyurethane-coated urea (PCU) were investigated and optimized. The nitrogen release characteristics of PCU were studied in both water and soil. The structural and chemical characteristics of PCU were examined. The PCU coating materials showed high density and good degradability, as well as superior controlled release properties. This product, with excellent controlled release properties, nontoxicity in soil, environmental friendliness, and low cost, could be especially useful in agricultural and horticultural applications.

Though potentially useful, agricultural byproducts are often discarded because of the lack of specific applications in many industries. However, they have suitable properties for use in the paper industry, according to recent literature. In this study, the suitability of rice husk, peanut husk, and garlic stem as raw materials for the manufacture of a new lignocellulosic bulking agent was investigated, and the best material to replace a commercial wood powder, widely used in Korean duplex board mills, was determined. Many powders were manufactured from agricultural byproducts, and their effects on the physical properties and drying energy requirements of handsheets were evaluated compared to those of a commercial wood powder. All of the powders improved the bulk and dryness after wet pressing, but a reduction in paper strength was unavoidable. In particular, the powder made from rice husk showed a greater bulk and increase in dryness after wet pressing than the commercial wood powder. These findings indicated that these three agricultural byproducts could be used as raw materials for the manufacture of bulking agents, and rice husk was the best agricultural byproduct to replace commercial wood powder in duplex board mills.

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer that is widely used to soften plastic products. It is an endocrine-disrupting compound, widely considered an environmental contaminant that is difficult to remove or degrade. The radial growth rate (ur), mycelial biomass, intracellular and extracellular activities of laccase and esterase, intracellular and extracellular contents of protein and glycogen, and the contents of soluble and insoluble glucans were evaluated in colonies of Lentinula edodes, grown in various concentrations of DEHP (0, 750, 1200, and 1500 mg/L) on agar. Glucose and yeast extracts were added to all media. The highest ur was shown in medium lacking DEHP, followed by that shown in the medium containing 1500 mg of DEHP/L. The greatest protein extracellular contents were observed in medium with added DEHP. The largest extracellular glycogen contents and mycelial biomass were found in media containing 1200 and 1500 mg of DEHP/L, respectively. These results suggest that DEHP was degraded and used as a substrate by L. edodes during diauxic growth (glucose metabolized first, followed by DEHP), and laccases were more important than esterases in the metabolism of DEHP. L. edodes can be used to remove DEHP from phthalate-polluted environments.

Safe and environmentally friendly oil-resistant packaging paper is strongly desired in the food packaging industry. In the present work, chitosan (CTS) and chitosan/cationic starch (CTS/CS) coated papers were prepared and characterized. The results indicated that both the CTS and CTS/CS coated papers were highly oil resistant, and their oil resistance was increased with an increase in coating weight. The CTS/CS composite showed better thermal stability and water resistance than CTS. Paper coated with the CTS/CS composite containing 1:2 CTS to CS achieved an oil resistance level as required for food packaging. The mechanism of CTS/CS oil resistance, which has not been reported, was investigated by SEM, HPLC and particle size analyzer. The high oil resistance of the CTS/CS-coated paper was attributed to the formation of a film on the surface of the paper and the electrostatic binding between CTS and fatty acid to prevent oil from permeating and transferring.

In past work, QSAR (quantitative structure-activity relationship) models of cinnamaldehyde analogues and derivatives (CADs) have been used to predict the activities of new chemicals based on their mass concentrations, but these approaches are not without shortcomings. Therefore, molar concentrations were used instead of mass concentrations to determine antifungal activity. New QSAR models of CADs against Aspergillus niger and Penicillium citrinum were established, and the molecular design of new CADs was performed. The antifungal properties of the designed CADs were tested, and the experimental Log AR values were in agreement with the predicted Log AR values. The results indicate that the improved QSAR models are more reliable and can be effectively used for CADs molecular design and prediction of the activity of CADs. These findings provide new insight into the development and utilization of cinnamaldehyde compounds.

With high temperature-heat treatment, the dimensional stability and durability of wood is improved and wood color is darkened as well. In this paper, alder birch wood (Betula alnoides) was treated by the Thermo-Vacuum Treatment (TVT). The changes of wood color parameters and the chemical composition were determined by the CIE1976 L*a*b* method and the chemical analysis method, respectively. The results were revealed as follows: (1) A lower value of lightness, L*, and a higher value of total color difference, △E*, were obtained at the higher heat-treatment temperatures and longer treatment time. (2) The higher the heat-treatment temperatures and the longer the heat-treatment times were, the lower the contents of hemicellulose and cellulose were and the higher the content of lignin was. Moreover, Fourier Transform infrared spectroscopy (FTIR) analysis demonstrated that the characteristic absorption peaks of cellulose, hemicellulose, and lignin diminished. The acetylation reaction of hemicellulose and the degradation reaction of groups of lignin side chain occurred during TVT. (3) TVT degraded the chemical composition of cell walls, which resulted in further changes of the wood color. A significant correlation existed between the differences of color indices and the differences of the chemical composition after TVT.

Straw powders were blended with hydrolyzed soy protein isolate (HSPI) modified urea-formaldehyde (UF) resins to produce biodegradable seedling containers. The tensile strength and the degradability of the seedling containers were characterized. Moreover, the degradation behavior of modified UF resins was investigated using 15N isotopic tracing, dynamic mechanical analysis, 13C CP/MAS NMR spectroscopy, and a scanning electron microscope-energy dispersive spectrometer. The results showed that the best tensile strength of the seedling containers made from HSPI-modified UF resins was improved by 6% compared with the seedling containers made from UF resins. The degradability of the seedling containers made from modified UF resins was improved 8.8 times more than that of unmodified UF resins. HSPI can lower the cross-linking degree of UF resins. The HSPI and urea-formaldehyde molecular chains in the resins were decomposed simultaneously in the soil. After degradation, nodular particles that appeared to be coalesced by small globular particles remained. In the process of degradation, modified UF resins can provide a nitrogen source for crops.