Volume 9 Issue 1

Oil palm trunks are a by-product of oil palm plantations and provide raw material to the woodworking industries. However, their resistance against degradation by termites needs to be improved; this study investigated hot pressing as a chemical-free method to improve resistance. The main objective was to assess resistance to termites conferred to oil palm wood by hot pressing at various temperatures (140, 180, and 220 °C) for a fixed duration of 8 min and maximum pressure of 2 MPa. The samples were the only available nutrition to subterranean termites (Coptotermes gestroi Wasmann) in a 4-week no-choice test. The thermally compressed oil palm wood did not show any significant effect of the pressing temperature on mass loss, but the surface damage to the samples with treatment at 220 °C indicated improved resistance to subterranean termites based on visual observation.

A grading countercurrent extraction method was used to separate polymeric proanthocyanidins (LPPC) from degreased Larix gmelinii bark, and the purification of LPPC was performed using HP-2MGL resin. The purity of LPPC was 26.37%. The cumulative recovery rate of purified product (LPPC-1) was 98.54% by the adsorption method of HP-2MGL resin. The purity of LPPC-1 was 99.79%. Catalytic hydrogenolysis tests of LPPC-1 were performed by means of a palladium carbon catalyst. The degradation rate was 67.5%, and the residual rate was 72.1%. The results of antioxidant ability showed that the degradation product (LHOPC) had more excellent antioxidant ability compared with LPPC-1, VC, TBHQ, grape seed extract, and pine bark extract. The results, through the analysis of the linear model of MALDI-TOF/TOF MS, revealed that LHOPC was oligomeric with the tetramer as the major component and the distribution ranging from the trimer to eleven units.

Nanocrystalline cellulose (NCC) was used to improve the anti-yellowing property of polyurethane (PU). The NCC was modified with 3-glycidoxypropyltrimethoxysilane (GPTMS) to enhance its compatibility with PU, and the surface-modified NCC was characterized by contact angle (CA), X-ray powder diffraction (XRD), and thermogravimetric analysis (TG). NCC/PU composite was examined by scanning electron microscopy (SEM), Fourier transform infrared spectrophotometer (FT-IR), and X-ray photoelectron spectroscopy (XPS). Anti-yellowing property of the NCC/PU composite was determined using the Chinese National Standard GB/T 23999-2009. The results showed that the CA between modified NCC and PU was decreased by 26.6% (with 8% GPTMS). The crystal structure of NCC was inconspicuously affected by the surface modification, while the thermal stability of modified NCC was enhanced by 5.5%. The surface-modified NCC particles were homogeneously dispersed in the PU (as shown in the SEM micrographs). FT-IR and O1s XPS survey spectra of NCC/PU composites indicated the oxidation of hydroxyl groups and the production of carbonyl groups, while the photochemical degradation of PU resulting from UV radiation was prevented by the addition of NCC. The anti-yellowing property of the NCC/PU composite with 1.5% surface-modified NCC was increased by 57.7% and the contribution was decreased when the content of modified NCC was 2.0%.

A field trial was performed to investigate the effect of municipal biowaste biochar (MBB) on rice and wheat growth, metal bioaccumulation, and greenhouse gas emissions in a rice paddy in eastern China. MBB was amended in 2010 before rice transplanting at rates of 0 and 40 t ha^-1 in a field experiment lasting one cropping year. MBB soil amendment significantly increased soil pH, total soil organic carbon, and total nitrogen. The growth and grain yield of rice and wheat was not affected with MBB application at 40 t ha^-1. MBB amendment did not influence the soil availability of Pb, Cu, and Ni, but significantly increased the soil availability of Zn and decreased the soil availability of Cd during both rice and wheat seasons. While MBB did not change the bioaccumulation of Pb, Cu, and Ni, the rice and wheat Cd accumulation was significantly reduced, and wheat Zn accumulation slightly increased with MBB amendment. Furthermore, total N2O emission during both rice and wheat seasons was greatly decreased, though total seasonal CH4 emission was significantly increased in the rice season. On the other hand, soil CO2 emission remained unaffected across crop seasons. Thus, MBB can be used in rice paddy for low carbon and low-Cd grain production, but the long-term effects remain unknown.

In Korea, Pinus densiflora is one of the most important indigenous tree species in terms of making high-value wood products. Therefore, Korean sawmills exercise extreme caution to prevent fungal discoloration such as that caused by sapstains and molds on the timber. In this study, the effectiveness of using natural crude wood vinegar to inhibit sapstains and molds, especially on Pinus densiflora (Japanese red pine) was examined. Pinus densiflora wood samples were dipped in absolute and diluted wood vinegar at different concentrations (1:1, 2:1, and 3:1; deionized water to wood vinegar dilution ratio) for 3 minutes and immediately air-dried. In addition, volatile wood vinegar was also used in this study to imitate the condition of wood vinegar when exposed to open air. The degree of discoloration was examined and evaluated every 2, 4, 6, and 8 weeks according to the ASTM D4445-91 Standard Method for laboratory test. Crude wood vinegar inhibited sapstains more efficiently than it inhibited molds. Wood vinegar at a 1:1 concentration was found to be the most optimum treatment for inhibiting sapstains for at least 8 weeks.

The processes of banknote deterioration in circulation and the factors causing this wear have been analyzed to determine the main factors in the process of banknote deterioration in real life circulation and to ascertain which of these factors could be simulated in the process of simulated circulation. The factors that should be taken into consideration during simulated circulation are systematic mechanical and chemical influences on a banknote. The developed Circulation Simulator Method was used to evaluate Ukrainian hryvnia banknotes to obtain artificially deteriorated banknote samples whose optical properties, weight change, air permeability, bursting strength, and stiffness were within the range of corresponding parameter changes for bank notes in actual circulation. The designed method consisted of multiple mechanical damages to tested banknotes by means of centrifugally rotating them within a closed container containing a wearing agent in the presence of a soiling mixture, which imitates the typical composition of soil in banknote circulation within Eastern Europe. The proposed method can be used to determine the durability of materials and to develop manufacturing processes for banknote production.

Many pulp mills and biorefineries today are focusing on the utilization of their residual lignin for economic return. Although lignin can be burned to produce energy, it also has the potential for the production of value-added products. Technical lignins have modified structure and contain different impurities, which depend on the original material, as well as the extraction process. Among the various techniques for lignin extraction, kraft and steam explosion processes are the most commonly used in the pulping and biorefinery industries, respectively. The objective of this work was to compare the thermal behavior of industrial lignins produced from kraft pulping and steam explosion, with that of their chemically extracted, purified forms. It was found that the purified lignins have very similar thermal properties to one another, while impurities in the industrial lignins significantly alter their thermal behavior, and hence their potential in value-added applications. The percentage of degradation from 200 to 600 °C and glass transition temperature of original steam-exploded lignin was 68.5% and 149.16 °C, while of original kraft lignin was 26.0% and 109.82 °C. These values were altered after purification to 61.0% and 158.99 °C for steam-exploded lignin; and to 40.0% and 129.82 °C for kraft lignin, respectively.

Alpha-grass was studied as the reinforcement in a starch-based polymer matrix. Mater-bi®-Y was chosen as a matrix due to its Young’s modulus, in line with that of polypropylene. The test specimens were injection molded and tensile tested. The obtained results were compared to glass fiber reinforced polypropylene. The reinforcing fibers increased the Young’s modulus significantly, obtaining values up to 7.2 GPa, comparable to those obtained with reinforced polypropylene. The contribution of the fibers to the final composite Young’s modulus was also studied, and it was found that was in line with other natural fibers contribution to polypropylene-based composites. Finally, it was found that the value of the efficiency factor of the module remained similar to that of natural fiber reinforced polypropylene.

Cellulose/collagen composite films with weight ratios of 30/1 (Blend-1) and 10/1 (Blend-2) were prepared using 1-ethyl-3-methylimidazolium acetate as a common solvent. The morphology of the films observed with a field-emission scanning electron microscope displayed a dependence on the ratio of cellulose/collagen. Collagen was successfully composited with cellulose without degradation and showed a denaturation temperature (Td) higher than that of native collagen. Fourier transform infrared spectroscopy suggested that there were hydrogen-bong interactions between collagen and cellulose in the regenerated composite films. Thermogravimetric analysis revealed that the maximum decomposition temperature (Tmax) of cellulose decreased after regeneration, while the Tmax of Blend-1 increased; however, it was reduced again for Blend-2. Elastic moduli from dynamic mechanical analysis exhibited a trend similar to that of Tmax. As indicated by X-ray diffraction, the distance between cellulose molecular chains was shortened for Blend-1 and elongated for Blend-2. Furthermore, the crystallization indices were calculated to be 75.3%, 68.3%, 66.2%, and 55.4% for native cellulose, regenerated films of cellulose, Blend-1, and Blend-2, respectively. These results confirm the dependence of the structural properties of composite films on cellulose/collagen ratios through the interactions between cellulose and collagen.

Throughout history, energy consumption and the demand for resources have gradually increased. The construction industry, by direct or indirect actions, consumes over 50% of the energy produced, is responsible for 30% of the CO2 emissions, and consumes more raw material than any other industrial activity. Architecture alone cannot solve global environmental problems, but it can contribute significantly. A high recyclability rate can be achieved through the management of renewable natural materials or waste. The application of prefabricated building systems can be an economical solution, saving energy and reducing waste. This work presents the prefabricated compressed straw panel as part of a paradigm shift toward sustainable architecture, which offers the opportunity to use new materials and construction systems but takes local and specific circumstances into account. The density of cereal straw for use in prefabricated compressed straw panel production in Badajoz, Spain was also studied.