A Study on the Manufacture and Physical Properties of Liquid Adhesive for Wood Preservation - Focusing on the Synthesis of Gelatin and Carrageenan -

In order to improve the usability of glue, a traditional adhesive material, and the gelation process of seaweed extract carrageenan, a liquid adhesive for wood preservation was prepared by mixing the two materials. The prepared wood adhesive was mixed with a 15 wt% aqueous solution of glue, λ-carrageenan, an antibacterial agent, an antifoaming agent, and the maximum adhesive strength of 1.80 Mpa was confirmed. As a result of comparison, the adhesive strength was superior to that of 5 different types of traditional natural adhesive ingredients (aqueous solution) and 1 type of polyvinyl acetate-based adhesive.

Effect of chemical modification and heat treatment on biological durability and dimensional stability of Pinus roxburghii Sarg.

Background: Depleting supplies of wood species with inherent natural durability has resulted in the focus being shifted to non-durable plantation grown and imported timber. Despite its abundant availability and better treatability, the use of Pinus roxburghii is limited to packing cases, crates, shutters, door and window frame, carpentry and joinery items due to its nondurable nature. Hence, to promote use of such timber for applications such as decking, cladding and facade elements chemical modification with a combination of citric acid and sodium hypophosphite, and heat treatment were explored to improve its service life. Methods: Chemical modification was performed using a water solution of citric acid (6.9%) and sodium hypophosphite (6.5%) followed by curing at 140°C for 8 hrs. Dimensional stability was determined by estimating the volumetric swelling coefficient and anti-swelling efficiency (ASE) of treated and control samples. Durability against fungus and termites was evaluated using a soil block bioassay and termite mound test as per standard methods. Results: Both chemical modification and heat treatment of P. roxburghii resulted in enhanced dimensional stability and biological durability compared to the untreated controls. Chemical modification and heat treatment resulted in 23.05% and 18.37% volumetric ASE, respectively. Results showed that a highly perishable species became significantly more durable after chemical modification, exhibiting 5–6 times less mass loss by termites in comparison to the controls. Wood samples modified with citric acid showed excellent resistance to both white and brown rot fungi and exhibited 14-15 times less reduction in mass compared with untreated samples. Conclusions: Citric acid chemical modification is an environment friendly process that improved the dimensional stability as well as resistance against biodegradation. These studies may provide valuable inputs to establish this mode of chemical modification as a cost-effective alternative to other chemicals for wood preservation. The concentrations of the chemicals and temperature for fixation may be varied to establish an optimum combination for best output.

Hydrogen Storage: Thermodynamic Analysis of Alkyl-Quinolines and Alkyl-Pyridines as Potential Liquid Organic Hydrogen Carriers (LOHC)

The liquid organic hydrogen carriers (LOHC) are aromatic molecules, which can be considered as an attractive option for the storage and transport of hydrogen. A considerable amount of hydrogen up to 7–8% wt. can be loaded and unloaded with a reversible chemical reaction. Substituted quinolines and pyridines are available from petroleum, coal processing, and wood preservation, or they can be synthesized from aniline. Quinolines and pyridines can be considered as potential LOHC systems, provided they have favorable thermodynamic properties, which were the focus of this current study. The absolute vapor pressures of methyl-quinolines were measured using the transpiration method. The standard molar enthalpies of vaporization of alkyl-substituted quinolines and pyridines were derived from the vapor pressure temperature dependencies. Thermodynamic data on vaporization and formation enthalpies available in the literature were collected, evaluated, and combined with our own experimental results. The theoretical standard molar gas-phase enthalpies of formation of quinolines and pyridines, calculated using the quantum-chemical G4 methods, agreed well with the evaluated experimental data. Reliable standard molar enthalpies of formation in the liquid phase were derived by combining high-level quantum chemistry values of gas-phase enthalpies of formation with experimentally determined enthalpies of vaporization. The liquid-phase hydrogenation/dehydrogenation reaction enthalpies of alkyl-substituted pyridines and quinolines were calculated and compared with the data for other potential liquid organic hydrogen carriers. The comparatively low enthalpies of reaction make these heteroaromatics a seminal LOHC system.

Wettability and Treatability of Sengon (Paraserianthes falcataria (L.) I.C. Nielsen) wood from NTB

The supply of wood from natural forests is decreasing as a result of the imbalance between harvesting and planting. The lack of wood supply from natural forests has resulted in relatively expensive wood prices. This can be anticipated by using fast-growing wood species. One type of fast-growing wood which is very abundantly available in NTB is sengon wood (Paraserianthes falcataria (L.) I.C. Nielsen). However, sengon wood has low durability so it is easily attacked by wood-destroying organisms. This condition can be overcome by making efforts to prevent wood damage in the form of preservation. This study aims to determine the wettability and treatability properties of sengon wood. The results of this study are expected to be basic information to improve the quality of sengon wood. The wettability test was carried out by measuring the contact angle between the liquid and the sample surface using the sessile drop method and the wood durability testing was carried out by measuring the retention and penetration of preservatives. The treatability test was carried out by measuring the absorption, retention, and penetration of preservatives. The results showed that the wettability of sengon is high with an equilibrium contact angle (θe) of 16.88 in the radial section and 12.51 in the tangential section. This shows that sengon wood has a good adhesion system for preservation. Treatability of sengon wood showed that the average retention and penetration are 10,21 kg/m3 and 7,33 mm. Based on the results of these measurements, sengon wood has met SNI 03-5010.1-1999 (wood preservation for housing and buildings).

The Resistance of Modified Manii Wood with Boric acid and Chitosan/Glycerol and Heating Against Fungi and Termites

Manii wood (Maesopsiss eminii Engl.) is a fast grown species that has low durability (class IV) and requires preservation. Boric acid is generally used in wood preservation. However, its application needs to be combined with other treatments to prevent from leaching. This study aimed to evaluate the resistance of manii wood after double impregnation of boric acid and chitosan or glycerol and heat treatment. Heating temperatures were 70ºC and 140ºC. The durability test was carried out against white rot fungus (Schizophyllum commune), dry wood termites (Cryptotermes cynocephalus), subterranean termites (Coptotermes curvignathus) according to SNI 7207-2014 standard, and field test based on ASTM D 1758-08 standard. The retention of boric acid in manii wood was 15,2 ± 1,0 kg ma−3. The interaction of boric acid and chitosan/glycerol impregnations and heat treatment significantly affected the wood resistance against decay fungi and termites. Impregnation of boric acid and glycerol by heating at 140ºC increased the resistance of wood against dry wood and subterranean termites. Double impregnation of boric acid and chitosan followed by heating at 140ºC was the best treatment in this research that improved significantly the resistance of manii wood against white rot fungi, dry wood termites and subterranean termites.

Azole Use in Agriculture, Horticulture, and Wood Preservation – Is It Indispensable?

Plant pathogens cause significant damage to plant products, compromising both quantities and quality. Even though many elements of agricultural practices are an integral part of reducing disease attacks, modern agriculture is still highly reliant on fungicides to guarantee high yields and product quality. The azoles, 14-alpha demethylase inhibitors, have been the fungicide class used most widely to control fungal plant diseases for more than four decades. More than 25 different azoles have been developed for the control of plant diseases in crops and the group has a world market value share of 20-25%. Azoles have proven to provide long-lasting control of many target plant pathogens and are categorized to have moderate risk for developing fungicide resistance. Field performances against many fungal pathogens have correspondingly been stable or only moderately reduced over time. Hence azoles are still, to date, considered the backbone in many control strategies and widely used as solo fungicides or as mixing partners with other fungicide groups, broadening the control spectrum as well as minimizing the overall risk of resistance development. This review describes the historic perspective of azoles, their market shares and importance for production of major crops like cereals, rice, oilseed rape, sugar beet, banana, citrus, and soybeans. In addition, information regarding use in amenity grass, in the wood preservation industry and as plant growth regulators are described. At the end of the review azoles are discussed in a wider context including future threats following stricter requirements for registration and potential impact on human health.

Preservative Treatments on Wood and Their Effects on Metal Fasteners

Wood as a building material has characteristics that make it attractive environmentally compared to other materials. It is an economic, historical and sustainable material. Many species of wood are naturally resistant to the action of the organisms that degrade them. However, species with this natural resistance are unable to meet the demand for wood and wood-based products, which have been growing year by year. The scarcity of species resistant to biological degradation forced man to use other less durable species, mainly of rapid growth, from reforestation, such as some species of Eucalyptus and Pinus. These species have moderate or no resistance to attack by biological agents and require preservative treatments. And to increase the life span of these fast-growing woods, protecting them from fungi, insects and other xylophagous organisms, several preservative agents are used, these compounds being highly toxic to these biodeteriorating organisms. It is known that the effectiveness of traditional wood preservation systems is due to the biocidal effect of the products used, however, they pollute the environment. Thus, there is an increasing need to develop effective preservative chemicals, non-toxic to humans and the environment.

Wood Processing For Construction

The article presents the positive and negative properties of wood, the technology of wood preservation and antiseptic treatment, and also deals with the fire retardant composition "Pyrol".

Determination of Pentachlorophenol in Environmental Samples by Spectrophotometry

Pentachlorophenol (PCP) (2,3,4,5,6- pentachlorophenol) is an organochlorine compound used as a pesticide and a disinfectant. PCP is used as a herbicide, insecticide, fungicide and disinfectant. Some applications include agricultural seeds (for nonfood uses), leather, masonry, wood preservation, cooling tower water, rope, and paper mills. Determination of Pentachlorophenol was based on the reaction of PCP with concentrated nitric acid followed by potassium iodide for the liberation of iodine. Liberated iodine reacted with leuco malachite green for the formation of green colour dye which was measured at 610 nm against a reagent blank. Parameters affecting the reaction were studied. The interfering effect of various species was also investigated and the methods were applied on some vegetables and fruit samples.