Volume 18 Issue 3

This study investigated the effect of a Pd/C catalytic extraction process on the hydrothermal depolymerization product properties of ethanol organosolv lignin (EOL) in supercritical ethanol. Phenolic products were separated and analyzed by gel permeation chromatography (GPC) and thermogravimetric (TG) analyses. The gas chromatography–mass spectrometry (GC-MS) analyses of obtained liquid oil products from depolymerized EOL confirmed the presence of value-added phenolics. Scanning electron microscopy (SEM) was used to observe the morphology of the char product. During ethanol organosolv lignin extraction, 90.5% purity of EOL was obtained. A high yield of EOL up to 39.6% from bamboo without catalysts and with higher yield of EOL up to 44.0% from 1% Pd/C catalyst under 200 °C. A high yield of liquid oil products, up to 65.4%, was recovered from EOL depolymerization under conditions of 240 °C, 240 min, 100 vol % ethanol, and 2% EOL, with only 24% solid residue. The main phenolic products were 2-methoxyphenol, 4-ethylphenol, 4-methoxy-2-methylphenol, 4-ethyl-2-methoxyphenol, 2,6-dimethoxy-phenol, and 2-methoxy-4-propylphenol.

The novelty of the research consists in the fact that the decayed wood was taken from an old icon, on which several consolidation treatments were applied, and the improvement indices of the decayed wood (by Anobiidae insects) were also determined. This research investigated two types of the most used consolidant (Paraloid B72 10% and Regalrez 1126 25%) solubilized in three types of solvents, to improve the properties of lime wood samples coming from cultural heritage objects that presented different degrees of degradation. Testing methodology for dimensional changes and wood swelling due to solvents impregnation, retention of consolidant in the degraded Tilia cordata wood, and the effectiveness of the consolidation treatment by the Mark hardness method was extensively presented. The highest amount of consolidant was observed when using Regalrez solution, and the lowest amount of consolidant was determined for Paraloid B72 solubilized in acetone. As a general conclusion, the use of Paraloid B72 or Regalrez 1126 for the consolidation of old and degraded lime wood, regardless of the type of solubilizer, will lead to stabilization of the wood degraded properties and the life span of the heritage object.

Effects of thermal modification were determined relative to chemical parameters of Pinus roxburghii. Thermal modification of wood was carried out at 80, 120, 160, and 200 °C for 2, 4, and 6 h. The chemical properties were different for different temperatures and different heating time. All parameters were similar except for cold water soluble extractives. Among the chemical properties studied, the maximum mean value of cold water extractives (8.20%), hot water soluble extractives (12.7%), holocellulose content (71.8%), and ash content (1.46%) were recorded at 120 °C, whereas the maximum mean values of alcohol benzene soluble extractives (13.9%) and lignin content (33.7%) were observed at 200 °C. The minimum mean value of cold water soluble extractives (5.82%), hot water soluble extractives (9.27%), holocellulose content (65.8%), and ash content (1.03%) were found to be at 200 °C, while the highest value of alcohol benzene soluble extractives 12.2% (control) and lignin content (28.0%) were found to be at 80 °C.

This study investigated the extraction and properties of an arabinogalactan polysaccharide from frost grape (FGP) as a potential alternative to gum arabic (GA). Collection date, solvent:feed ratio (S:F), chip size, C-18 filtration, ultrafiltration, freeze drying versus spray drying, methanol pre-extraction, and water absorption were examined. Sugar composition, elemental analysis, dietary fiber content, emulsification activity index (EAI), emulsification stability index (ESI), and viscosity were used to evaluate the extracts. Exudates collected in March from live stems were viscous with high percentage solids and FGP, while May collections were watery with low percentage solids and FGP. Frost grape stems were collected, chipped, and classified by size. The extraction system utilized pressure or vacuum to increase contact between the chips and extraction water. A S:F ratio of ca. 24% gave an excellent yield of FGP. Chips between 1.8 and 3.8 mm gave the highest mass yields. Pre-extracting the chips with methanol and C-18 filtration of the water extract both yielded a lighter product. The EAI for the FGP was higher than that for GA; however, its ESI was lower. Ultrafiltration of the crude extract separated glucose, fructose, and sucrose from the FGP. FGP with glucose, fructose, and sucrose adsorbed water and became darker.

Biochar made from seaweed biomass of marine farms established for water pollutant remediation may be a promising amendment for soil remediation in the same coastal territory. The study aimed to assess the soil Cu-immobilizing, pH neutralizing, and nutrient improvement capabilities of a seaweed biochar when incorporated into degraded soil of the same coastal territory (Puchuncaví District, central Chile). Experimental design considered five treatments; degraded soil of Puchuncaví valley (C-), C- amended with either local seaweed biochar (B), vermicompost (V), or its mixture (BV), and a background soil (C+). Experimental soils were placed in pots and kept in a greenhouse (4 weeks). Lolium perenne was then sown and cultivated until week 11. Treatments amended with biochar (B and BV) significantly increased soil pH, available nitrogen and decreased Cu²⁺ ions. These treatments reached very high EC values but had no negative effect on plant yield. Regarding plant growth, V and BV significantly increased biomass, but V resulted in higher yield because of its higher nutritional status. It was concluded that seaweed biochar, made from local seaweed biomass of a coastal marine water pollutant remediation farm, may be an effective soil amendment for degraded soils of the same coastal territory, although its combination with an organic amendment should be considered.

This report discusses the biometry and microscopic features of Crataegus azarolus wood fibers. A Crataegus azarolus tree was selected and cut from the gardens of Neka city (Mazandaran province). At a breast height, 2.5 m and 3.5 m height, three 5 cm thick disks were prepared and in the transverse direction, the test samples were cut and evaluated sequentially 2 x 2 cm long by 3 cm long from the pith to the bark. The anatomical properties of C. azarolus wood were studied using a light microscope. Wood anatomical features of C. azarolus are as follows: diffuse-porous with multiple vessel grouping in the radial direction (in most cases), homogenous rays, simple perforation plates, alternate intervessel pits, and the average length of vessel elements shorter than 350 microns. There was a significant difference in the fiber length, fiber diameter, fiber lumen diameter, and fiber wall thickness, both in the transverse direction and in the longitudinal direction of the Crataegus azarolus tree stem. The biometric properties of the fibers increased from the pith to the bark. The average fiber length, fiber diameter, fiber lumen diameter, and cell wall thickness of the fibers were 0.78 mm, 22.53 µm, 18.6 µm, and 4.5 µm, respectively.

A wood-based sandwich panel with a corrugated core was developed as a building material. A matched-die mold manufactured from commercial plywood was used to fabricate the corrugated panels through a cold-forming process. A cold-setting resin was applied on southern yellow pine (Pinus spp.) veneers with an average thickness of 4 mm, and four plies of them were formed into a corrugated geometry using a wooden mold. When the resin was cured, the corrugated panel of veneers retained the corrugated shape after load removal. Facesheets of the sandwich structures were fabricated using three plies of the same veneers. To evaluate the effect of this corrugated geometry on the structural performance, the same veneers — regarding number, thickness, and orientation — used for the sandwich panel were adopted to fabricate laminated flat panels. Both sandwich and laminated flat panels were submitted to a four-point bending test. The results confirmed the sandwich effect, i.e. a 1741% increase in the bending stiffness of sandwich panels compared to that of laminated flat panels. Sandwich panels developed in this study were compared to Structural Insulated Panels (SIPs), wood-framed structures known as stud walls, and sandwich panels produced using a hot-pressing technique. The cold-formed sandwich panels had higher structural performance than commercial building materials.

Effects of protective measures were evaluated relative to the compression strength in the direction parallel to the grain of laminated veneer wood (LVL). For this purpose, laminated panels were prepared from Scots pine, Oriental beech, Castanea sativa, and sessile oak wood veneer by gluing them with Desmodur vinyl trie ketonol acetate (D-VTKA), polyvinyl-acetate (PVAc) dispersion D4 adhesive, resorcinol formaldehyde (RF), and melamine formaldehyde (MF). The samples were impregnated with a mixture of wax, linseed oil, and coated with a synthetic-based translucent varnish. The control samples (without the treatment described above), impregnated samples, and varnished samples were kept in the external environment for 1 y and in an ultraviolet (UV) environment for 240 h. The samples were tested to determine the air-dried density, retention amount, and compression strength. The results indicated that, in terms of outdoor conditions, the varnished proceeding provided better protection compared to the impregnated proceeding. The best result for compression strength was obtained on the Oriental beech samples with RF and MF glues. The ratio of the UV environment to represent the external environment was 89%.

Cellulose acetate is an important product derived from cellulose. Cellulose acetate can be used in a variety of applications including coatings, textile fibers, consumer goods, filtration membranes, composites, laminates, pharmaceutical, and medical items. Rice husk is a lignocellulosic material that contains cellulose and hemicellulose. The aims of this study were to determine the effect of process variables on the cellulose acetate product formation by ultrasound-assisted acetylation using iodine as a catalyst and to characterize the cellulose acetate product. The research was conducted through the delignification, bleaching, acetylation, and characterization processes. The results showed that the optimum yield of cellulose acetate was obtained at the temperature of 60 °C, the reaction time of 50 min, the weight of the catalyst of 10% of cellulose weight, and the ratio of cellulose and acetic anhydride of 1:5 (w/v). The acetylation process using iodine as a catalyst with an ultrasound-assisted method was more effective than the conventional acetylation (acetic acid glacial and sulfuric acid as a catalyst).

Among various industries, the construction sector has one of the greatest impacts on the environment. Minimizing the resource use and the waste outputs in this sector could be fulfilled by applying circular economy (CE) strategies. Although research on CE in the construction sector has increased in recent years, there have not been remarkable adjustments by applying these strategies to the construction industry. The purpose of this study was to examine the impacts of using CE strategies in the construction sector. A framework was adapted to guide the application of different CE strategies at the end-of-life of buildings. The framework was assessed by a case study of a residential building in mass timber. This study evaluated the application of CE strategies from the environmental aspect with the life cycle assessment (LCA) method. The results confirmed that circular strategies can deliver lower environmental impacts.