Search Results (22)

Environmentally friendly or “green” materials are receiving growing attention due to their sustainability and low energy requirements during production. One such material is mycelium, which can be described as a particle board where fungal hyphae act as a natural adhesive instead of synthetic binders. This biodegradable and low-energy material is commonly used in packaging and interior design. However, its relatively weak mechanical properties limit its use in load-bearing or structural applications. To mitigate the main drawback of mycelium—its poor mechanical performance—an original mycelium–wood biocomposite with unique properties was developed. Using an original methodology and equipment, it was determined that its dynamic modulus of elasticity and coefficient of damping depend not only on the wood-to-mycelium ratio within the biocomposite, but also on the orientation of the wooden lamella embedded in it. Subsequently, the influence of ambient temperature on the viscoelastic properties of samples with different “configurations” was assessed. The samples were conditioned for 24 h at temperatures ranging from –20 °C to +40 °C. Results showed that temperature had a lesser effect on the biocomposite compared to natural wood. As temperature increased, the MOEd of samples with 37% wood decreased by about 3–4%, while that of samples with 11% wood remained nearly unchanged. The coefficient of damping increased by 20–30% across all cases. Full article

Agricultural residues offer promising opportunities for the development of biocomposites. Durian husk, a lignocellulosic by-product abundantly available in Southeast Asia, and bamboo waste, an underutilized biomass resource, present considerable potential for sustainable particleboard production. This study focuses on developing single-layer bio-based particleboards using varying proportions of durian husk and bamboo waste bonded with urea formaldehyde resin. The fabricated boards were evaluated for thickness swelling, modulus of rupture, and internal bond strength according to relevant European standards. Results indicated that all particleboards met the Type P1 requirements for general-purpose use under dry conditions, as specified in BS EN 312:2010. The findings demonstrate the feasibility of converting agricultural waste into value-added, eco-friendly materials, supporting waste valorization, promoting circular economy practices, and contributing to the development of bio-based materials. Full article

Cement-bonded particle boards are gaining popularity globally due to their durability, strength, and, more importantly, environmental sustainability. The increasing demand for these materials has also created the necessity for the sustainable recycling of these materials. In this study, the potential to recycle wood-wool cement board (WWCB) waste into new lightweight insulation biocomposite material was examined. The waste WWCBs were crushed and separated into a fine aggregate fraction, and WWCB production line residues were also collected and compared. The crushed WWCBs were used to produce biocomposites with various compaction ratios and different binder-to-aggregate ratios. To improve their thermal properties and reduce their density, hemp shives were used to partially replace the recycled WWCB aggregate. Their physical, mechanical (compressive and flexural strength), and thermal properties were evaluated, and the drying process of the biocomposites was characterized. The results showed that the density of the produced biocomposites ranged from 390 to 510 kg/m³. The reduction in density was limited due to the presence of cement particles in the aggregate. The incorporation of hemp shives allowed us to reduce the density below 200 kg/m³. The thermal conductivity of the biocomposites ranged from 0.054 to 0.084 W/(mK), placing the material within the effective range of natural biocomposites. This research has demonstrated that industrially produced WWCBs can be successfully recycled to produce sustainable lightweight cement-bonded insulation materials. Full article

The present study focuses on the elimination of delamination during the drilling of a linen-based biocomposite material in epoxy resin used for the manufacture of sports kayaks, depending on the tool material, cutting conditions, and the use of additional wooden support plates. In the present study, HSS (high-speed steel) and Carbide cutting tools without coatings, with the same geometry and two types of cutting conditions (n = 1500 rpm, f_n = 0.05 and 0.1 mm/rev) were used. A Sololite-type wooden backing plate was used to aid in reducing delamination. The results show that the additional support plates significantly reduced delamination by up to 80% both at the material inlet and especially at the drill hole outlet. In this study, the use of a lower feed rate (f_n = 0.05 mm/rev) per tooth was shown to have a significant effect on reducing the delamination of biocomposite materials with flax fibers, which are generally known to be difficult to machine. The Carbide cutting tool shows significantly better results both in terms of its wear and in terms of delamination of the biocomposite material. The highest delamination was obtained without the use of a backing board at the tool exit after 50 drilled holes of 3509 µm. With the use of a backing board, this delamination decreased to 693 µm after 50 drilled holes. Full article

Finding eco-friendly products that are beneficial to the environment and serve as tools for sustainable development is a contemporary challenge. This work illustrates the recovery of bio-waste-based materials, which not only improve the hygrothermal properties of gypsum but also promote the paper and wood recycling processes in a circular economy approach. The samples were subjected to tests for density, water absorption, ultrasonic pulse velocity, flexural strength, compressive strength, and thermophysical property characterization. A statistical analysis of variance was used to study the impact of waste on the physico-mechanical behavior of gypsum, leading to the development of predictive models that can be used to predict and optimize the performance of bio-composites in various applications. The results revealed a reduction in mechanical strength with the addition of waste, but the samples still exhibit superior insulation properties, surpassing commonly used standard boards. By adding ouate and wood wastes to a mass of 20% in its natural state, the gypsum becomes lighter and acts as a better insulator with a reduced density, thermal conductivity, and ultrasound velocity of up to 50%, 57%, and 83%, respectively. These findings show the significant implication of reducing environmental impacts while contributing to the promotion of sustainable building practices, both in new construction projects and in building renovations. Full article

Nowadays, biocomposites represent a new generation of materials that are environmentally friendly, cost-effective, low-density, and not derived from petroleum. They have been widely used to protect the environment and generate new alternatives in the polymer industry. In this study, we incorporated untreated jute fibers (UJFs) and alkaline-treated jute fibers (TJFs) at 1–5 and 10 phr into TSR 10 natural rubber as reinforcement fillers. These composites were produced to be used in countersole shoes manufacturing. Untreated fibers were compared to those treated with 10% sodium hydroxide. The alkali treatment allowed the incorporation of fibers without compromising their mechanical properties. The TJF samples exhibited 8% less hardness, 70% more tensile strength, and the same flexibility compared to their pure rubber counterparts. Thanks to their properties and ergonomic appearance, the composites obtained here can be useful in many applications: construction materials (sound insulating boards, and flooring materials), the automotive industry (interior moldings), the footwear industry (shoe soles), and anti-static moldings. These new compounds can be employed in innovative processes to reduce their carbon footprint and negative impact on our planet. Using the Lorenz–Park equation, the loaded composites examined in this study exhibited values above 0.7, which means a competitive load–rubber interaction. Scanning electron microscopy (SEM) was used to investigate the morphology of the composites in detail. Full article

This study investigated the mechanical, physical, and thermal properties of three-layer particleboards produced from annual plant straws and three polymers: polypropylene (PP), high-density polyethylene (HDPE), and polylactic acid (PLA). The rape straw (Brassica napus L. var. Napus) was used as an internal layer, while rye (Secale L.) or triticale (Triticosecale Witt.) was applied as an external layer in the obtained particleboards. The boards were tested for their density, thickness swelling, static bending strength, modulus of elasticity, and thermal degradation characteristics. Moreover, the changes in the structure of composites were determined by infrared spectroscopy. Among the straw-based boards with the addition of tested polymers, satisfactory properties were obtained mainly using HDPE. In turn, the straw-based composites with PP were characterized by moderate properties, while PLA-containing boards did not show clearly favorable properties either in terms of the mechanical or physical features. The properties of straw–polymer boards produced based on triticale straw were slightly better than those of the rye-based boards, probably due to the geometry of the strands, which was more favorable for triticale straw. The obtained results indicated that annual plant fibers, mainly triticale, can be used as wood substitutes for the production of biocomposites. Moreover, the addition of polymers allows for the use of the obtained boards in conditions of increased humidity. Full article

The construction industry is continuously searching for sustainable materials to combat the rapid depletion of global resources and ongoing ecological crises. Biocomposites have recently received global attention in various industries due to their renewability, low cost, and biodegradability. Biocomposites’ potential as a sustainable substitute in construction can be understood by identifying their diverse applications. Moreover, examining their life cycle environmental and economic impacts is important. Therefore, this study is a novel attempt to encompass biocomposites’ construction applications and their environmental life cycle performance. Statistical analysis is done related to the temporal distribution of papers, publishers, literature type and regions of studies. First, this paper reviews the latest research on the applications of natural fiber biocomposites in construction with their key findings. The applications include fiber reinforcements in concrete, external strengthening elements, internally filled hollow tubes, wood replacement boards, insulation, and non-structural members. The second part covers the life cycle assessment (LCA) and cost studies on biocomposites. The life cycle studies are currently rare and require more case-specific assessments; however, they highlight the benefits of biocomposites in cost savings and environmental protection. Finally, this study provides key suggestions for increasing the applicability of biocomposites as sustainable construction materials. Full article

Biocomposite materials have a significant function in saving the environment by replacing artificial plastic materials with natural substances. They have been enrolled in many applications, such as housing, automotive engine components, aerospace and military products, electronic and circuit board components, and oil and gas equipment. Therefore, continuous studies have been employed to improve their mechanical, thermal, physical properties. In this research, we conduct a comprehensive review about corn fiber and corn starch-based biocomposite. The results gained from previous studies were compared and discussed. Firstly, the chemical, thermal, and mechanical properties of cornstarch-based composite were discussed. Then, the effects of various types of plasticizers on the flexibility of the cornstarch-based composite were addressed. The effects of chemical treatments on the properties of biocomposite using different cross-linking agents were discussed. The corn fiber surface treatment to enhance interfacial adhesion between natural fiber and polymeric matrix also were addressed. Finally, morphological characterization, crystallinity degree, and measurement of vapor permeability, degradation, and uptake of water were discussed. The mechanical, thermal, and water resistance properties of corn starch and fibers-based biopolymers show a significant improvement through plasticizing, chemical treatment, grafting, and cross-linker agent procedures, which expands their potential applications. Full article

The share of bio-based materials in modern construction needs to grow more rapidly due to increasingly stringent environmental requirements as a direct result of the climate emergency. This research aims to expand the use of hemp concrete in construction by replacing traditional lime binder with magnesium oxychloride cement, which provides a faster setting and higher strength, opening the door for industrial production. However, the negative feature of this binder is its low water resistance. In this work, the water resistance of magnesium cement was studied, and the possibilities of improving it by adding fly ash, various acids and nano-silica were considered. Nano-silica and citric acid showed the most significant impact, increasing the binder water resistance up to four times, reaching softening coefficient of 0.80 while reducing the compressive strength of the magnesium cement in a dry state by only 2–10%. On the downside, citric and phosphoric acid significantly extended the setting of the binder, delaying it 2–4 times. Regarding board production, prototype samples of hemp magnesium biocomposite demonstrated compressive strength of more than 3.8 MPa in the dry state but only 1.1–1.6 MPa in the wet state. These results did not correlate with binder tests, as the additives did not increase the strength in the wet state. Full article

Biocomposite boards (BcBs) composed of hemp shives and corn starch are known as thermal insulating or structural building materials. Therefore, they must be stable during exploitation. However, BcBs are exposed to microorganisms present in the environment, and it is of great interest to investigate the biodegradation behaviour of these materials. This work identified microorganisms growing on BcBs that contain either Flovan CGN or expandable graphite as flame retardants and selected fungi such as Rhizopus oryzae and Aspergillus fumigatus to test the way they affect the materials of interest. For this purpose, the enzymatic activity of cellulases and amylases produced by these organisms were determined. In addition, the apparent density as well as compressive strength of the affected boards were evaluated. The results showed that apparent density and compressive strength deteriorated in BcB composition with the Flovan CGN flame retardant. At the same time, the level of deterioration was lower when the expandable graphite was used, suggesting that it also acts as an antimicrobial agent. A scanning electronic microscopy analysis was employed to monitor the growth of microorganisms in the BcBs. Such analysis demonstrated that, regardless of BcB composition, fungi easily penetrate into the middle layers of the material. Full article

Thermal insulation bio-composites made of plant origin by-products as bio-aggregates are one of the ways to decrease the impact of the building and construction sector on CO₂ emissions. In this study, three bio-aggregates were analysed for their potential use in the production of bio-composites with potato starch binder. Technologically important properties, such as particle size, shape and compacted bulk density, as well as properties of the resulting bio-composites were identified. The main characteristics of the aggregates are relatively similar: density of 80–100 kg/m³, thermal conductivity of 0.042–0.045 W/m∙K, specific heat capacity of 1240–1330 J/g∙K, kinetic water absorption from 456–584%. This leads to similar basic properties of the produced bio-composites: density around 200 kg/m³, thermal conductivity 0.053–0.062 W/m∙K, specific heat capacity 1250–1450 J/kg∙K, with a difference in compressive strength ranging from 0.2 to 0.8 MPa. Created starch binder and agricultural by-product filler materials could be used in the production of boards where strength is required, for example, envelope and wind barrier boards, and thermal insulation boards under floors. Full article

In this study, for the first time, the potential of rose flowers and lavender straw waste biomass was studied as feeding lignocellulose substrates for the cultivation of newly isolated in Bulgaria Ganoderma resinaceum GA1M with the objective of obtaining mycelium-based bio-composites. The chemical characterization and Fourier Transform Infrared (FTIR) spectroscopy established that the proximate composition of steam distilled lavender straw (SDLS) and hexane extracted rose flowers (HERF) was a serious prerequisite supporting the self-growth of mycelium bio-materials with improved antibacterial and aromatic properties. The basic physico-mechanical properties of the developed bio-composites were determined. The apparent density of the mycelium HERF-based bio-composites (462 kg/m³) was higher than that of the SDLS-based bio-composite (347 kg/m³) and both were much denser than expanded polystyren (EPS), lighter than medium-density fiber board (MDF) and oriented strand board (OSB) and similar to hempcrete. The preliminary testing of their compressive behavior revealed that the compressive resistance of SDLS-based bio-composite was 718 kPa, while for HERF-based bio-composite it was 1029 kPa and both values are similar to the compressive strength of hempcrete with similar apparent density. Water absorbance analysis showed, that both mycelium HERF- and SDLS-based bio-composites were hydrophilic and further investigations are needed to limit the hydrophilicity of the lignocellulose fibers, to tune the density and to improve compressive resistance. Full article

More than 124 million tons of oranges are consumed in the world annually. Transformation of orange fruit generates a huge quantity of waste, largely composed of peels. Some attempts to reuse by-products derived from citrus waste have been proposed for energy production, nutrient source or pharmaceutical, food and cosmetic industries. However, their use in the building sector had not been researched. In this study, orange peels, in five different ratios, from 100% of wet peels to 75% and from 0% of dry peels to 25%, were submitted to a thermo-compression procedure. They were evaluated according to their physical (bulk density, water absorption, thickness swelling, surface soundness and thermal conductivity) and mechanical properties (bending strength and modulus of elasticity). The results showed that orange peels can be used as thermal insulation material. The addition of dried peels makes the structure of the board heterogeneous and thus increases its porosity and causes the loss of strength. Hence, the board with the sole use of wet peel, whose thermal conductivity is 0.065 W/mK while flexural strength is 0.09 MPa, is recommended. Full article

Environmental contamination, extensive exploitation of fuel sources and accessibility of natural renewable resources represent the premises for the development of composite biomaterials. These materials have controlled properties, being obtained through processes operated in mild conditions with low costs, and contributing to the valorization of byproducts from agriculture and industry fields. A novel board composite including lignocelullosic substrate as wheat straws, fungal mycelium and polypropylene embedded with bacterial spores was developed and investigated in the present study. The bacterial spores embedded in polymer were found to be viable even after heat exposure, helping to increase the compatibility of polymer with hydrophilic microorganisms. Fungal based biopolymer composite was obtained after cultivation of Ganoderma lucidum macromycetes on a mixture including wheat straws and polypropylene embedded with spores from Bacillus amyloliquefaciens. Scanning electron microscopy (SEM) and light microscopy images showed the fungal mycelium covering the substrates with a dense network of filaments. The resulted biomaterial is safe, inert, renewable, natural, biodegradable and it can be molded in the desired shape. The fungal biocomposite presented similar compressive strength and improved thermal insulation capacity compared to polystyrene with high potential to be used as thermal insulation material for applications in construction sector. Full article