Trends in Chemical Wood Surface Improvements and Modifications: A Review of the Last Five Years

Increasing the use of wood in buildings is regarded by many as a key solution to tackle climate change. For this reason, a lot of research is carried out to develop new and innovative wood surface improvements and make wood more appealing through features such as increased durability, fire-retardancy, superhydrophobicity, and self-healing. However, in order to have a positive impact on the society, these surface improvements must be applied in real buildings. In this review, the last five years of research in the domain of wood surface improvements and modifications is first presented by sorting the latest innovations into different trends. Afterward, these trends are correlated to specifications representing different normative, ecologic and economic factors which must be considered when expecting to introduce a wood treatment to the market. With this review, the authors hope to help researchers to take into consideration the different factors influencing whether new innovations can leave the research laboratory or not, and thereby facilitate the introduction of new wood surface treatments in the society.

PROTECTIVE WOOD TREATMENT WITH AN OLIGOMER CONTAINING STYRENE UNITS

Currently, much attention is paid to the protective treatment of wood materials. This allows you to protect wood from adverse factors and extend the service life of products based on it. At the same time, not a little, an important criterion is the ratio of the price of the protective composition and its quality. The article discusses the possibility of using an oligomer for the protective treatment of natural wood, obtained on the basis of by-products of the production of polybutadiene and modified with secondary polystyrene. Considering the fact that this waste has not found its application, its use makes it possible to obtain not only valuable and affordable compositions based on it, but also to solve a number of environmental problems. For the modification, an oligomer with a bound styrene content of about 50% was used. The process was carried out at 200°C in the presence of a desiccant. At high temperatures and in the presence of atmospheric oxygen, destruction of both oligomer and secondary polystyrene occurs. The resulting destruction products interact with each other with the formation of new macromolecules containing an increased amount of styrene groups and the appearance of functional groups containing oxygen in the polymer chains. Protective treatment of natural wood with the obtained impregnating compounds allows to reduce water absorption and swelling of birch samples. This treatment allows you to extend the life of wood products.

Bioethanol Production from Locally Growing Algal Biomass: A Promising and Cost-effective Approach

Background: Energy production and consumption ratio form the hallmark of the economic prosperity of a country. To keep up with the demand and supply of energy a major switch to biofuels is reasoned but the cost associated with production and the choice of raw material forms two major economical and ethical concerns, especially in the under-developed and developing countries where the food is not sufficiently available to everyone. In this scenario, the use of food sources as raw material becomes unjustified. Purpose: To address these issues, here we made an effort to obtain bioethanol from a non-edible and easily available resource that requires a modest cost of production i.e., a locally available algal bloom. Also, different methods of pre-treatment were employed and scrutinized for their efficacy. These methods of pre-treatment are very cost-effective and easy to administer. Materials and Methods: The algal biomass was pre-treated separately in three ways viz., freeze-thawing, mechanical disruption and rotten wood treatment. The algal cake left out after extraction of lipid content for biodiesel production was also used as a fourth sample. After pre-treatment, the supernatant was collected and estimated for reducing sugar content and allowed to ferment using Saccharomyces cerevisiae. A distillate was obtained and checked for ethanol percentage through gas chromatography. Results: The mechanically disrupted sample yielded the highest percentage of ethanol followed by algal cake, freeze-thawing and rotten wood treatment. Conclusion: Given present food scarcity, the non-edible algae could be a better alternative for bioethanol production as compared to the use of conventional food crops. Through this study, we have found that a better yield can be achieved if the algal biomass is pre-treated via mechanical disruption.

Eucalyptus wood treatment and leaching behavior of CCB (Chromated Copper Borate): a field test in Brazilian Midwest

The use of Chromated Copper Borate (CCB) for wood treatment is known with several studies on a laboratory scale. However, there is a lack of field studies to analyze the effect of the CCB over time. This study aimed to evaluate the wood properties of Eucalyptus urophylla S.T. Blake x Eucalyptus grandis W. Mill ex Maiden (called E. urograndis), treated with CCB as well evaluate the leaching of chromium, copper and bore (Cr/Cu/B) in field test. The field experiment, with wood treated and untreated (no CCB application), was installed in 2016 and remained until 2018. Wood physico-mechanical properties were evaluated for each condition (treated and untreated) and at three different time: at 0, 1 and 2 years of field exposure. The elements (Cr/Cu/B) losses (leaching) were determined by the difference in the quantification of each element retained in the wood (retention), from year 0 (amount of original elements) in relation to years 1 and 2 of field exposure. The preservative treatment of E. urograndis wood with CCB was efficient to maintain its physical and mechanical properties (mass loss, basic density, rupture and elasticity modulus) during the 2 years of field exposure. The E. urograndis wood without CCB treatment showed reductions in the physical-mechanical properties, indicating their low natural durability. High leaching (close to 100%) for boron was observed. In addition, the total of CCB retention has not changed (statistically) after 2 years.

Azoles for Renewable Energy Development and Wood Treatment

Azole applications in energy are empirical and, despite increasing interest in azole and energy research, many challenges remain in synthesizing and processing azoles with functionality for energy applications. The use of azole in wood treatment has been effective to some extent in producing durable wood; however, there is still the need for improving the treatment of wood species. This chapter seeks solutions which are developed systematically with scientific validation principles. Consequently, this chapter aims to provide a concise overview of integrating azoles in materials used for renewable energy processing and applications, and wood treatment, with an outlook on challenges and opportunities.

A Model for Strategic Analysis in Wood Treatment Companies

Agribusiness is related to the economic vocation of Brazil due to climate, soil, water abundance, favorable relief, and the high insolation index with luminosity throughout the year. The productive chains in this segment represent approximately 30% of the gross domestic product, which makes Brazil the largest producer and exporter of different products of animal and plant origin. Forestry with planted forests makes Brazil the world’s largest producer and one of the main exporters of pulp, being Mato Grosso do Sul State a major producer with the highest growth of planted eucalyptus forests in the last 10 years. Academic studies available in the literature related to economic and managerial aspects do not cover more specifically small and medium rural properties that have been dedicated to forestry, especially to wood treatment and its strategic aspects. This study aims to propose a model for the analysis of strategic positioning in wood treatment companies. Methodologically, it is a non-probabilistic and intentional for convenience, exploratory and qualitative single case study. Interviews, visits to the company, and consultation of management and accounting documents were used as an instrument of data collection. Techniques already consolidated in the literature and market, such as Pestel analysis, Porter’s five forces, and SWOT analysis were used for conducting the strategic positioning analysis. The analysis results, however, are presented by means of a complete mapping of strategic positioning of the studied company and its strategies for the differentiation of its products and the effort to consolidate brand in an agricultural commodity. Study limitations are related to the difficulty of using it in other companies of the same business segment since it is a single case, but this fact does not invalidate the academic contributions. In this sense, new research lines are presented as the possibility of mapping brand consolidation in a forestry commodity and using forest residues from wood harvesting.

Preparation of cellulose-rich membranes from wood: effect of wood pretreatment process on membrane performance

In this study cellulose-rich membranes were fabricated from untreated and treated hardwood biomass solutions in 1-ethyl-3-methylimidazolium acetate ([Emim][OAc])—dimetylsulfoxide (DMSO) system via wet phase separation. Wood treatment methods aimed to get purified cellulose fraction of wood. Treatment sequence was as followed: deep eutectic solvent pretreatment, sodium chlorite bleaching, and alkaline treatment. Resulted biomass after each treatment step was characterized by chemical composition and crystalline fraction content. Flat-sheet membranes were produced from biomass samples after each treatment step. Characterization of membranes included measurements of pure water permeability and (poly)ethyleneglycol 35 kDa retention, Fourier-transform infrared and Raman spectroscopy, X-ray diffraction measurements and thermogravimetric analysis. The study revealed that it was possible to fabricate membrane from untreated wood as well as from wood biomass after each of treatment steps. The resulted membranes differed in chemical composition and filtration performance. Membrane prepared directly from untreated wood had the highest permeability, the lowest retention; and the most complex chemical composition among others. As treatment steps removed lignin and hemicelluloses from the wood biomass, the corresponding membranes became chemically more homogeneous and showed increased retention and decreased permeability values.

CARACTERIZAÇAO DE DANOS EM EDIFÍCIOS HISTÓRICOS: ESTUDO DE CASO EM QUATRO EDIFICAÇÕES DO MÉDIO OESTE DO RN

RESUMO: A conservação e manutenção das construções históricas é fundamental para transferência de conhecimento e perpetuação do patrimônio da sociedade. O estudo da patologia das edificações contribui para identificação dos mecanismos, causas e origens de problemas que afetem a vida útil dessas edificações. O objetivo do trabalho foi realizar uma avaliação das manifestações patológicas nas edificações de importância história em municípios do Médio Oeste do estado do Rio Grande do Norte, situado no Nordeste brasileiro. Os procedimentos metodológicos empregados envolveram o levantamento da importância histórica e a inspeção in loco, feita com aplicação de Fichas de Identificação dos Danos, registro fotográficos e medições. A Matriz de Gravidade, Urgência e Tendência (GUT) foi utilizada para definir a prioridades nas intervenções futuras. Destacaram-se a ocorrência de: infiltrações; retração e expansão da alvenaria por absorção de água; retração e expansão por movimentação térmica; agentes biológicos e suas excreções; e ineficiência de elementos usados como verga. Como terapias sugeridas, indicam-se técnicas com selagem com resina epóxi ou uso de nata de cimento com consistência adequada nas fissuras, e para as manchas, degradação, descascamento e disgregação a remoção das partes afetadas e preparação do local para ser repintado ou aplicado novo revestimento. A ordem de priorização indicou a sequência de correções: substituição de madeiramento de cobertura, tratamento das fissuras, desagregação, disgregação, descascamento e manchas. ABSTRACT: The conservation and maintenance of historic buildings is essential for the transfer of knowledge and perpetuation of society's heritage. The study of the pathology of buildings contributes to the identification of mechanisms, causes and origins of problems that affect the useful life of these buildings. The objective of the work was to carry out an evaluation of the pathological manifestations in buildings of historical importance in cities in the Middle West of the state of Rio Grande do Norte, located in the Northeast of Brazil. The methodological procedures employed involved the survey of historical importance and on-site inspection, carried out with the application of Damage Identification Sheets, photographic records and measurements. The Gravity, Urgency and Tendency Matrix (GUT) was used to define priorities for future interventions. The occurrence of: infiltrations; masonry retraction and expansion by water absorption; retraction and expansion by thermal movement; biological agents and their excretions; and inefficiency of elements used as lintels. As suggested therapies, techniques with sealing with epoxy resin or use of cement cream with adequate consistency in the cracks are indicated, and for stains, degradation, peeling and disgregation the removal of the affected parts and preparation of the site to be repainted or applied again coating. The order of prioritization indicated the sequence of corrections: replacement of covering wood, treatment of cracks, disintegration, disgregation, peeling and stains.

Assessment of Hydraulic Conductivity of Some Nigerian Hardwood Timbers to Four Timber Treatment Chemicals through Quantitative Anatomical Studies

Aim: Hydraulic conductivity following the Hagen-Poiseuille Law is a quantitative approach to determine the treatability of wood by chemicals. The hydraulic conductivities of the ten selected Nigerian hardwood timber species to four wood treatment chemicals were estimated, using Hagen-Peiseuille equation. Materials and Methods: Ten timber species of marketable size and age were sourced from the forestry Departments of Enugu, Anambra and Abia States of Nigeria. Maceration were carried out following standard procedures. The viscosities in centipoises (cp) of the four wood treatment chemicals were measured in a viscometer test, while the hydraulic conductivities were calculated using the Hagen-Peiseuille equation. Results: The results obtained show that the different woods responded differently to the chemicals. Treatment with Folithion 200 showed higher conductivity in Triplochiton scleroxylon (9.01 mm-3S-1× 10-5), followed by Mansonia altissima, Milicia excelsa and Terminalia superb. The order of conductivity to treatment with Actellic 25EO was Terminalia superba > Mansonia altissima > Gmelina arborea, > Khaya ivorensis. Ceiba pentandra gave the highest conductivity of 8.58 mm-3S-1× 10-5, followed by Afzelia africana and Canarium schwenfurthii to the chemical Termitox. While Triplochiton scleroxylon gave the highest conductivity of 6.52 mm-3S-1×10-5, followed by Milicia excels and Terminalia superba to the chemical Solignum. Conclusion: Folithion 200 would be effective on Milicia excels, Mansonia altissima and Gmelina arborea, Actellic 25 EO would be effective on Khaya ivorensis, Terminalia superb and Antiaris toxicaria while Termitox would be effective on Ceiba pentandra, Afzelia Africana and Canarium schweinfurthii.

Transcriptomics analysis and co-expression network revealing candidate genes for laccase activity of Lenzites gibbosa

Background Lenzites gibbosa is a common white-rot fungus of Polyporaceae in the cold temperate zone which cause spongy white decay of wood. Results In this study, the lignin degradation pathway of L. gibbosa at 5-time points under wood treatment was studied by RNA-Req technology. A total of 5232 DEGs were identified from 15 libraries. In 0–3 days, the mycelia are in the adaptive stage, and the mycelia began to proliferate within 3–5 days. After 5 days, the number of DGEs decreased significantly, the mycelium growth entered the platform stage, and the life activity was basically stable. In the secondary metabolism, oxidoreductase such as laccase, 2-oxoglutarate-Fe (II) type oxidoreductase, peroxisomal hydratase-dehydrogenase, dual-functional monooxygenase dominated and increased steadily, and manganese peroxidase appeared in the middle stage. With the accumulation of lignin intermediate products, P450 and ABC transporters were from the inhibition to the activation. Weighted gene co-expression network analysis (WGCNA) showed that among the 24 modules 6 modules were significantly correlated with laccase activity and the most correlated were turquoise and blue module. The central hub genes were also identified, including gene_7458, gene_61, gene_7458, gene_1741, gene_11087 which were consistent with the DGEs. These genes have high connectivity, module membership, and gene significance in the module. The enrichment analysis of GO and KEGG pathway indicated that the genes involved in cell cycle, citrate cycle (TCA cycle), nicotinate and nicotinamide metabolism, mitochondrial outer membrane, succinate dehydrogenase, carboxypeptidase and exopeptidase activity, flavin adenine dinucleotide binding, oxidoreductase activity, acting on the CH-CH group of donors, quinone or related compound as acceptor pathway were highly related to laccase synthesis pathway. Construction of gene co-expression network and hypothetical L. gibbosa laccase synthesis pathway. Conclusion This study focused on the screening of L. gibbosa degradation of lignin-related genes. And, this is the first study reporting co-expression patterns of a gene network in L. gibbosa laccase activity after wood treatment which is helpful to understand the synthesis pathway of laccase and improve the activity of laccase, which can be used to increase the rate of lignin degradation by L. gibbosa in the further.