Boron-based fire retardancy for natural polymeric materials.

To reduce CO2 emissions and save grey energy, natural materials like wood and wooden materials are becoming more and more important. However, these products are particularly sensitive to moisture, as they can be attacked by mould or decay fungi. In contrast to mould growth, which typically is associated with visual impairment and health problems, the growth of decay fungi may result in structural defects which clearly must be excluded. Up to now it is mostly assumed that wooden materials are more sensitive to such attack than solid wood. Therefore, different wood fibre insulation materials were inoculated with decay fungi and exposed to different climates to determine the requirements for the decay process and to compare them with the requirements of decay by the same fungi of solid wood. The results prove that some natural fibre materials are equally or even more resistant to decay fungi than solid wood, while others are less. The resistant products can therefore be assessed like solid wood – for which already temperature dependent thresholds and in part also transient decay prediction models are available. Maybe even specific higher moisture levels can be acceptable. However, the results also suggest a differentiated view on natural fibre insulations, as they have a very different susceptibility to wood decay. Uniform and significantly lower limits than for solid wood are not justified.

Natural materials are renewable, sustainable, have less environmental impact and have lower embodied energy. Materials like rock wool, and expanded and extruded polystyrene are of non-renewable nature, have a greater environmental impact and high embodied energy. Natural insulation materials have less effect on the environment as compared to materials like rock wool, and expanded and extruded polystyrene. The mean thermal conductivity of natural materials like wood fiber is almost same and that of insulation materials like wood waste, kenaf insulation board and coconut husk insulation board is comparable with that of materials like rock wool, and expanded and extruded polystyrene. The other natural derived materials like oriented strand board, particleboard, plywood, hardboard and solid wood have a mean thermal conductivity slightly higher than materials like rock wool, and expanded and extruded polystyrene.

Bio-based adhesives are derived from renewable resources such as plant-based materials, animal by-products, and microbial sources. Latex-based bio adhesives, specifically those made from natural latex derived from plant sources, have garnered significant research interest. While natural rubber remains the most commonly used bio source for latex adhesives, this study explores the potential of Pterocarpus indicus wild (PIW) latex as an alternative and discusses modifications that can be made to enhance its adhesive properties. Additionally, this research examines the effect of additives such as Polyvinyl Alcohol (PVA) on the adhesive properties of natural latex while evaluating their capacity for adhesive performance. The major challenges faced by existing bio-based adhesives, including low bonding strength and water resistance are acknowledged. Consequently, this study offers guidance on advancing new plant sources for bio-based adhesives, addressing the limitations of current adhesive products. Adhesives are social substances and can be defined as a mixture in a liquid or semi-liquid state, capable of joining permanently to surfaces, by an adhesive process [1]. Bio- based adhesives are a type of adhesive that is made from natural and renewable resources, such as plant-based materials [2]. These adhesives are becoming increasingly popular due to their sustainability and environmentally friendly nature, as they have a reduced carbon footprint and are biodegradable. The disadvantages of the current bio sealants can restrict their use in some circumstances. Their lower strength and longevity compared to conventional adhesives are significant drawbacks. Some bio-based adhesives are also moisture-sensitive and may lose their adhesion when exposed to moisture or high humidity [3]. Due to the higher expense of obtaining and processing natural materials, bio- based adhesive production has another disadvantage. Additionally, bio-based adhesives' scalability and broad use may be constrained by the lack of readily available natural materials. Additionally restricting their use in some applications, some bio-based adhesives have a lower shelf life than conventional adhesives.

Increasing attention for green design is promoting the need of innovation both in processes and in products used in boatbuilding. Wood is undoubtedly the most ancient and natural material used for boatbuilding and it is particularly suitable within the strip-planking technique. However, the use of conventional epoxy resins in wooden boats reduces the eco-friendly capability of the entire construction. A valuable solution to this problem may be represented by resins derived by natural and renewable re-sources, commonly addressed as bio-based resins. In the present research activity, two bio-based resins used as adhesives in the strip-planking technique based on Iroko wood were investigated. Experimental tests for the mechanical characterization according to the UNI EN 302-1 standard were performed. The mechanical properties of the two bio-based adhesives were compared to the mechanical properties of a conventional epoxy adhesive providing similar results. Furthermore, a new methodology to evaluate the shear modulus and strength was applied. The systematic analysis carried out gave interesting results on the possibility of coupling Iroko wood and bio-based adhesives within the strip-planking technology, in order to enhance the eco-friendly capability of wooden boats.

Wood and timber are significant building materials used in construction projects for centuries; since the earliest buildings, they have been featured prominently as a construction tool, structural material, and aesthetic finish. But what part is the material playing in today’s sector, what benefits is this bringing to the contractors and end users, and what issues should they be aware of? The use of wooden products remains mostly for aesthetics and to fit the general theme selected by architects or designers.With forests not so greatly featured in the natural landscape of the Gulf, most of the wood used for the construction industry must be imported, which raises issues of availability, cost, and transportation. However, the region’s location does ease the potential challenge of availability. The sources of wood vary according to the type with supplies being offered from countries worldwide. Plywood is typically sourced from Indonesia, China, and Brazil; softwood timber from Chile, Austria, New Zealand, and Romania; and, moreover, hardwoods from Africa, North America, and Indonesia only to name but a few.Over the past two decades, a renaissance in wooden architecture has occurred with the development of new wooden building systems and design strategies, elevating wood from a predominantly single-family residential idiom to a rival of concrete and steel construction for a variety of building types, including high rises (Mayo, Solid wood: Case studies in mass timber architecture, technology and design, Taylor & Francis, Abingdon, 2015). Wood and timber in architecture offer unparalleled environmental as well as construction and aesthetic benefits and are of growing importance for professionals and academics involved in green design.This article will endeavor to bring back the uses of wood and timber in buildings in the The Cooperation Council for the Arab States of the Gulf (GCC) as a natural material that can be used to achieve green building and are to cool the interior spaces by reflecting the direct sun when having lattice windows or ceiling. There is a good example in using these natural materials in ceilings and wooden screens to shade and make a comfort zone of traditional houses, as well as nowadays that have been reflected in contemporary architecture in order to increase energy efficiency. Modern architecture is inspired by heritage elements in which wood and timber surge the intimate scale of the street and interior as esthetical elements.KeywordsGreenery and designingIncrease energy efficiencyWood in constructionArabian PeninsulaLimestoneBrick and mudWooden shuttersMashrabiya or ShanasheelRecyclableBiodegradableGCC countriesEnergy efficiencyBadgersThermal transmittanceScreensCooling agent

Naturally-based adhesives (Biobased adhesives) have attracted tremendous attention in the last years, especially based on the general “green” ideas as well as to replace oil- or gas-derived adhesives. So far, despite the huge effort in research and development and an inestimable number of papers and reports published, a commercial breakthrough is still missing. Only in a few special niche markets some significance of the use of such natural adhesives is shown. But mainly in the huge applications, such as wood bonding and production of wood-based panels, the use of naturally-based adhesives is still insignificant. This chapter highlights opportunities and challenges for naturally-based adhesives, including requirements and limitations. Instead of using natural substances as adhesives, small and well-defined platform chemicals, as they are produced in biorefineries, can be used for the synthesis of various types of materials, among them also adhesives. Additionally, two special topics are highlighted, i.e., lignin and 5-hydroxymethylfurfural (5-HMF). Mimicking nature tries to copy nature's materials or at least the idea for suitable materials usable as adhesives, as nature shows incredible examples of adhesion, such as underwater or with quick and frequent de- and rebonding.

<p class="first" id="d5619913e53">To reduce CO2 emissions and save grey energy, natural materials like wood and wooden materials are becoming more and more important. However, these products are particularly sensitive to moisture, as they can rot or be attacked by decay fungi. In the past years, new and detailed knowledge on the decay process of wood was gained. This knowledge allows the definition of more sophisticated limit conditions depending on coinciding heat and moisture and their duration, which can replace simple steady state limits like the widely used 20 % by mass. For wooden materials and natural fibre insulations, in most regulations the moisture limits are even lower - although there are certainly materials that are more resistant than solid wood itself. Therefore, within a project dealing with wood fibre as interior insulation, which is exposed to increased moisture levels during the winter months, the durability of such materials against decay is compared at different critical temperature and humidity conditions to the one of solid wood. Based on these results, the more resistant wood fibre materials can be evaluated like solid wood. Thus, their performance can be predicted more accurately by hygrothermal simulations and their application fields accordingly be extended.

Soft-fiber-reinforced tough and fatigue resistant hydrogels

Variation in surface roughness, wettability and some plywood properties after preservative treatment with boron compounds

Introduction. The analysis of flame retardants and extinguishing agents used for preventing and extinguishing fires in an ecosystem is carried out. It is shown that at present there are no weatherproof, environmentally friendly and cost effective extinguishing agents capable of stopping wood and peat burning. Purpose and objectives. Development of cost effective and environmentally friendly synthetic agents capable of both flame retarding and extinguishing natural combustible materials. Materials and methods. Synthetic dispersions of ammonium phosphates of two- and three-valence metals, as well as wood and peat fireproofed by them are the object of the study. Physical and chemical properties of synthesis products in comparison with their fire retarding efficiency are examined. Fireproofing, fire extinguishing, as well as physical and chemical properties of synthesized products are determined using GOST-regulated methods of thermal and chemical analysis, scanning electron microscopy and original methods. Results and discussion. The formulation of Kompleksil synthetic compound effective in extinguishing and fireproofing wood and peat is optimized using a full factorial experiment. At the same time, the inflow of volatile nitrogen containing products into the gaseous phase is identified as the dominating burning inhibition process common for natural combustible materials. The weather resistance (preservation of fireproof properties in respect of forest combustible materials at 79 mm precipitation), forest and environment enhancement (improvement of mineral nutrition conditions and growth of forest plant communities) properties of Kompleksil compound are identified. Conclusions. A cost effective synthetic compound based on natural mineral materials showing fireproofing and extinguishing efficiency when protecting forest combustible materials and peat is developed. This compound was tested in the process of extinguishing real wildfires; its weather resistance is identified, and the positive response of forest plant communities to the application of this multiple action compound is registered. The use of Kompleksil allows to reduce time expenditures and fire extinguishing agent consumption when extinguishing wildfires, which significantly reduces material damage.

Self-assembling hierarchical flexible cellulose films assisted by electrostatic field for passive daytime radiative cooling

Bone fracture healing involves complex physiological processes that require biological events that are well coordinated. In recent decades, the process of fracture healing has been upheld through various treatments, including bone implants and bio-adhesive utilization. Bio-adhesion can be interpreted as the process in which synthetic or natural materials adhere to body surfaces. Bio-based adhesives have superiority in many value-added applications because of their biocompatibility, biodegradability, and large molecular weight. The increased variety and utilization of bio-based materials with strong adhesion characteristics provide new possibilities in the field of orthopedics in terms of using bio-based adhesives with excellent resorbability, biocompatibility, ease of use, and low immunoreactivity. The aim of this review is to provide comprehensive information and evaluation of the various types of bio-based adhesives used clinically with a specific focus on their application in orthopedics. The main properties of bio-based adhesives, their benefits, and challenges compared with the traditional bio-based materials in orthopedics, as well as the future perspectives in the field, have also been outlined and discussed.

Conventional Lithium-ion batteries contain volatile liquid compounds that can leak and violently react with the environment leading to a fire.1 Solid polymer electrolytes (SPEs) are one solution as these flexible materials do not contain any volatile components. Additionally, they enable the use of high energy density lithium (Li) metal anodes.2 However, Li metal battery utilization is hampered by the dendrite growth.3 Upon cycling lithium metal is plated unevenly on the lithium metal anode side. Such dendrites can grow through the electrolyte and cause the battery to fail by short circuit. Solid block copolymer electrolytes are a class of SPEs that contains a mechanical reinforced block and an ion conducting block doped with a Li salt.4 The block immiscibility induces microphase separation, producing ordered morphologies on the nanometer scale.5 The seminal work done by K.J. Harry et al. 6 on solid polystyrene-b-poly(ethylene oxide) (SEO) block copolymer electrolyte led to a better understanding of Li dendrite formation and growth. Using Li symmetric cells dendrite evolution was observed and imaged by a non-destructive tool, hard X-ray microtomography. To go toward the application, batteries were imaged by hard X-ray microtomography. The batteries are made of a Li metal anode, a SEO electrolyte layer and a composite cathode. The cathode deposited onto on Aluminum (Al) foil, contains LiFePO4 as active material, SEO electrolyte as binder, and carbon black. Hard X-ray microtomography enables to visualize the microstructural changes at the Li/SEO and SEO/cathode interfaces to get insight on the battery failure mechanisms. The batteries were cycled at 90°C at a C/20 charge rate and a C/8 discharge rate (Figure 1a). Prior and after battery cycling, the electrode-electrolyte interfaces were imaged by hard X-ray microtomography as shown in figure 1b and 1c, respectively. We found that the supposed intimate Li/SEO interface undergoes a strong delamination phenomenon that leads to the formation of voids (Figure 1b). Using a rendering image software, the void fraction can be measured all along the Li/SEO interfaces, and its effect on the battery capacity fading be estimated. References J.-M. Tarascon, M. Armand, Nature, 414 (2001) 359.M. Armand, J.-M. Tarascon, Nature, 451 (2008) 652.M. Rosso, C. Brissot, A. Teyssot, M. Dollé, L. Sannier, J.-M. Tarascon, R. Bouchet, S. Lascaud, Electrochimica Acta, 51 (2006) 5334.M. Singh, O. Odusanya, G.M. Wilmes, H.B. Eitouni, E.D. Gomez, A.J. Patel, V.L. Chen, M.J. Park, P. Fragouli, H. Iatrou, N. Hadjichristidis, D. Cookson, N.P. Balsara, Macromolecules, 40 (2007) 4578.V. Abetz, T. Goldacker, Macromolecular Rapid Communications, 21 (2000) 16.K.J. Harry, D.T. Hallinan, D.Y. Parkinson, A.A. MacDowell, N.P. Balsara, Nature Materials, 13 (2014) 69. Figure 1

Title: Study of Structural Elements of Traditional Mbaru Niang House TraTraditional houses are built using natural materials and environmentally friendly construction techniques, taking into account climate, topography, and local culture. The connection structures in traditional houses are closely related to responding to local climate conditions. For example, the connections in the traditional house of Mbaru Niang in Wae Rebo, NTT, can withstand wind and earthquake loads due to its location in the mountains, which are prone to earthquakes and tornadoes. This study aims to analyze the connection structure in the Mbaru Niang traditional house using Iwamura's sustainability theory. The method used in this research is descriptive qualitative, collecting data from previous literature. The results show that the structure of Mbaru Niang is formed by the material characteristics sourced from the environment by the Wae Rebo community, which are used according to their natural properties, such as worok wood and bamboo, which are flexible materials, allowing the building structure to adapt to the flexibility of the materials. Flexibility can also be seen in the connection techniques that withstand earthquake loads and wind forces. This finding will produce a design proposal for connection techniques in contemporary buildings inspired by the local wisdom of connection techniques in Mbaru Niang houses.

Cloth simulation usually refers to using computer programs to simulate the true representation of flexible tensile materials in nature. This article is based on the traditional Mass-Spring model. The main improvement method is: giving a reasonable range of Hook variable to the original model, constraining the abnormal deformation of the spring under the action of powerful external force, which is called Hyperelastic phenomenon; In the case of the same types of traditional force, imitating the natural performance of the wind field to cloth, increase the pressure difference caused by the Bernoulli effect, resulting in a more realistic cloth simulation in wind field; Using the Symplectic Euler method to solve the differential equation of particle motion, since this method belongs to the implicit Euler method, it has a more stable performance than the explicit Euler method; Using mature geometric calculation formulas, collision detection is realized with less space and time complexity. Through this experiment, it is verified that the cloth simulation optimization based on this method has a better real-time and On-site reduction effect.