Search Results (74)

Bamboo materials usually exhibit creep behavior under external loading conditions. This study conducted the compressive creep property research on bamboo scrimber, a commonly seen natural fiber-reinforced composite material. Firstly, the compressive creep strain data under various stress amplitudes were recorded on the basis of a four-step compressive load. Secondly, different Zener models were adopted in analyzing the recorded compressive creep process. Finally, a creep strain prediction method was proposed with the help of the verified model and the stress level-related empirical equations. The following main conclusions were drawn: for bamboo scrimber, the modified Zener model based on various-order Caputo fractional derivatives can provide precise expression in analyzing the creep performance of the material under compressive load than the traditional Zener model, as well as predict the creep strain increase property under other stress levels with a relatively shorter experimental period. Therefore, this method is valuable for promotion in modern industry. Full article

Instance segmentation of moso bamboo cells is a critical step in quantitative structural analysis of bamboo materials and plant phenomics research. Moso bamboo tissues are mainly composed of vascular bundles and parenchyma cells. Within vascular bundles, fiber cells exhibit thick cell walls and extremely dense arrangements, whereas vessel cells are characterized by large diameters and complex internal structures. These features frequently lead to blurred boundaries, structural complexity, and local overexposure in microscopic images, making it difficult for traditional segmentation algorithms to achieve stable and accurate results. Although the U-Net has demonstrated outstanding performance in biological microscopic image analysis, its feature extraction capability and boundary recognition stability remain insufficient when dealing with the composite structure of moso bamboo. To address these challenges, this study proposes an improved model based on a multi-scale attention mechanism, termed MBMSA-UNet (Moso Bamboo Multi-Scale Attention U-Net). Building upon the encoder–decoder architecture of U-Net, the proposed model introduces a multi-scale channel-spatial attention block, aiming to handle the pronounced morphological and scale differences among vessels, fibers, and parenchyma cells. By adaptively reweighting features at different scales, the model enhances cross-layer feature fusion and strengthens responses to key regions, thereby effectively suppressing local overexposure interference and emphasizing boundary features between different cell types. Experimental results demonstrate that, compared with the U-Net and several of its improved variants, MBMSA-UNet achieves higher segmentation accuracy and greater robustness on microscopic images of moso bamboo, providing a solid foundation for fine-grained quantitative analysis of complex bamboo tissues. Full article

The impact of pretreatment methods on the fermentation quality and nutritional profile of bamboo silage was assessed to determine the optimal ensiling strategy. Tender bamboo underwent microwave, ultrasound, alkali, and irradiation pretreatments. Subsequently, a four-factor, three-level L9 (3⁴) orthogonal experiment was employed, utilizing pretreated bamboo as the substrate. The experiment evaluated the effects of silage time (30, 45, 60 days), moisture content (55%, 60%, 65%), cellulase addition [2, 4, and 6 mg/g FM (Fresh weight)], and silage inoculant addition (0.5, 5, 50 mg/g FM). Results indicated that γ-ray irradiation pretreatment effectively reduced lignin and cellulose content while increasing reducing sugars levels approximately fourfold compared to the control group. Six out of the nine treatment groups exhibited superior comprehensive fermentation quality scores, with silage time demonstrating the most significant influence on the fermentation quality of tender bamboo silage. The order of influence was silage time > silage inoculant level > moisture content > cellulase, with a silage time of 30 days, a silage inoculant level of 0.5 mg/g FM, a moisture content of 65%, and a cellulase level of 2 mg/g FM, all contributing to enhanced fermentation quality. Regarding nutritional composition, silage time significantly impacted crude protein and soluble sugar levels, with optimal levels observed at 30 and 60 days, respectively. Moisture content primarily affected soluble sugar levels, followed by neutral detergent fiber, with an optimal level of 55%. Other factors showed minimal effects. Based on fermentation quality and nutritional component analysis, and prioritizing fermentation quality while considering cost-effectiveness, the optimal ensiling conditions for bamboo were determined to be a silage time of 30 days, a moisture content of 65%, an addition of 2 mg/g FM of cellulase, and an addition of 0.5 mg/g FM of silage inoculant. Full article

The increasing demand for sustainable polymer composites has driven the development of hybrid laminates that combine natural, recycled, and synthetic reinforcements while maintaining adequate mechanical performance. However, the combined influence of stacking sequence and mineral filler addition on the mechanical behavior of such sustainable hybrid systems remains insufficiently understood. In this study, sustainable hybrid laminated composites based on epoxy reinforced with glass fiber (G), bamboo fiber (B), and flex banner (F) were fabricated with varying stacking sequences and calcium carbonate (CaCO₃) filler contents (0 and 1 wt.%). A total of nine laminate configurations were produced and evaluated through flexural and impact testing. The results demonstrate that mechanical performance is strongly governed by laminate architecture and filler addition. The bamboo-dominant G/B/B/B/G laminate containing 1 wt.% CaCO₃ exhibited the highest flexural strength (191 MPa) and impact resistance (0.766 J/mm²), indicating a synergistic effect between reinforcement arrangement and CaCO₃-induced matrix strengthening. In contrast, the lowest performance was observed for the G/F/B/F/G configuration without filler. Overall, all hybrid composites outperformed neat epoxy, highlighting the potential of bamboo–flex banner hybrid laminates with CaCO₃ filler for sustainable composite applications requiring balanced mechanical properties. This work aligns with SDG 12 by promoting resource-efficient circular-economy practices through the utilization of flex banner material and natural fibers as reinforcements in epoxy-based hybrid composites. Full article

Petroleum-based plastics are non-renewable and degrade poorly, persisting in the environment and causing serious ecological pollution, so urgent development of alternatives is needed. In this study, all-bamboo fiber thermosetting plastics (BTPs) were successfully prepared through selective sodium periodate oxidation of bamboo fibers followed by hot-pressing. The results demonstrate that the oxidation treatment effectively enhanced fiber reactivity and facilitated the formation of dense composite materials during hot-pressing. Compared with petroleum-based plastics (e.g., PVC), BTPs exhibit outstanding mechanical properties: flexural strength reaches 100.73 MPa, tensile strength reaches 83.31 MPa, while the 72 h water absorption and thickness swelling rates are as low as 5.36% and 4.59%, respectively. This study also reveals the mechanism by which residual lignin affects material microstructure formation through competitive oxidation reactions. Although it imparts initial hydrophobicity, it hinders complete fiber activation, leading to the formation of micro-defects. Furthermore, BTPs can completely degrade in 1% NaOH solution within 24 h, demonstrating excellent degradability. This research provides a new strategy for developing high-performance, degradable all-bamboo-based materials and promotes the value-added utilization of bamboo resources. Full article

Developing sustainable, high-performance biomass composites is crucial for replacing non-renewable structural materials. In this study, a “bamboo steel” composite was fabricated using a multilevel modification strategy involving alkali pretreatment, toughened resin impregnation, and surface functionalization. Bamboo fibers were treated to remove hemicellulose and lignin, enhancing porosity and interfacial bonding. The bamboo scaffold was subsequently impregnated with a thermo-plastic polyurethane-modified epoxy resin to create a robust, interpenetrating network. The optimized composite (treated at 80 °C) exhibited a flexural strength of 443.97 MPa and a tensile strength of 324.14 MPa, demonstrating exceptional stiffness and toughness. Furthermore, a superhydrophobic coating incorporating silica nanoparticles was applied, achieving a water contact angle exceeding 150° and excellent self-cleaning properties. This work presents a scalable strategy for producing bio-based structural materials that balance mechanical strength with environmental durability. Full article

This study investigates the Mode II fracture behavior of bamboo–coir–rubber (BCR) hybrid composite panels developed as sustainable alternatives for wood-based panels used in structural applications. The composites were fabricated using alternating bamboo and coir layers within a polypropylene (PP) thermoplastic matrix, with styrene–butadiene rubber (SBR) incorporated as an additive at 0–30 wt.% to enhance interlaminar toughness. Commercial structural plywood was tested as the benchmark. Mode II interlaminar fracture toughness (G_IIc) was evaluated using the ASTM D7905 End-Notched Flexure (ENF) test, supported by optical monitoring to study crack monitoring and Scanning Electron Microscopy (SEM) for microstructural interpretation. Results demonstrated a steady increase in G_IIc from 1.26 kJ/m² for unmodified laminates to a maximum of 1.98 kJ/m² at 30% SBR, representing a 60% improvement over the baseline and nearly double the toughness of plywood (0.7–0.9 kJ/m²). The optimum performance was obtained at 20–25 wt.% SBR, where the laminated retained approximately 85–90% of their initial flexural modulus while exhibiting enhanced energy absorption. Increasing the initial notch ratio (a₀/L) from 0.2 to 0.4 caused a reduction of 20% in G_IIc and a twofold rise in compliance, highlighting the geometric sensitivity of shear fracture to the remaining ligament. Analysis of Variance (ANOVA) confirmed that the increase in G_IIc for the 20–25% SBR laminates relative to plywood and the unmodified composite is significant at p < 0.05. SEM observations revealed rubber-particle cavitation, matrix shear yielding, and coir–fiber bridging as the dominant toughening mechanisms responsible for the transition from abrupt to stable delamination. The measured toughness levels (1.5–2.0 kJ/m²) position the BCR panels within the functional range required for reusable formwork, interior partitions, and transport flooring. The combination of renewable bamboo and coir with a thermoplastic PP matrix and rubber modification hence offers a formaldehyde-free alternative to conventional plywood for shear-dominated applications. Full article

This research contributes to the field of materials engineering through an analysis of the wear performance of both glass fiber-reinforced epoxy composites (GFEC) and bamboo fiber-reinforced epoxy composites (BFEC). This study aims to assess the wear performance, defined by mass loss, of the composites under various factors: load, speed, time, nanoclay content, and composite type. Specimens are subjected to wear tests by a pin-on-disc tribometer. Composite wear performance is studied through Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) as predictive models. Experimental runs are planned based on the Box–Behnken design of RSM to present a regression model that is then checked with an ANOVA analysis; afterwards, training and testing are performed using an ANN model to improve predictive accuracy. As per the results, GFEC exhibits lower mass loss compared to BFEC. For both of the composites, the mass loss is drastically reduced by the addition of nanoclay. The addition of nanoclay has more pronounced effects on BFECs than on GFECs. ANN predictions are found to be better in agreement with the experimental values compared to those derived from the RSM model. Scanning Electron Microscopy (SEM) analysis provides insight into wear mechanisms. This study demonstrates the effectiveness of a statistical and machine learning approach in optimizing wear performance in composite materials. Full article

Unsaturated polyester resins (UPRs) were synthesized from camphoric acid and diluted with styrene, partially replaced (up to 30%) by trimethylolpropane triacrylate (TMPTA). Rheological tests showed increased but sustainable viscosity due to TMPTA’s higher polarity. These UPRs served as matrices for composites reinforced with non-woven bamboo and flax mats from recycled waste. Mechanical testing revealed that C_f-UPR/TMPTA30 exhibited the highest tensile strength (25.2 MPa) and modulus (0.96 GPa), compared to 18.7 MPa and 0.74 GPa for the styrene-based resin, respectively, attributed to greater cross-link density. Bamboo composites showed lower tensile properties (13.6 MPa) due to random fiber orientation and porosity, while flax-reinforced systems, especially C_f-UPR/TMPTA30–FLAX, reached 42.7 MPa tensile and 95.5 MPa flexural strength, indicating synergy between TMPTA-modified resin and flax fibers. Dynamic-mechanical analysis confirmed stable thermo-mechanical behavior, and water uptake tests showed reduced absorption (by ~10%), suggesting improved fiber/matrix adhesion. SEM images revealed brittle fracture and fiber pull-out in styrene systems, but fiber breakage and ductile textures in TMPTA-based ones, proving better stress transfer. Thermal analysis indicated slightly earlier degradation onset for TMPTA-modified resins but higher char yield in fiber composites. Overall, TMPTA substitution and flax reinforcement enhance the mechanical, interfacial, and thermal properties of bio-based UPRs, supporting sustainable high-performance composites. Full article

Flattened bamboo (FB) exhibits pronounced structural and chemical heterogeneity between outer and inner layers and between nodes and internodes. These variations critically influence its interfacial performance with waterborne acrylic coatings. This study aimed to clarify how primer layer configuration and substrate heterogeneity jointly affect the coating adhesion, hardness, and abrasion resistance of FB. Three coating schemes—one primer and one topcoat (1P1T), two primers and one topcoat (2P1T), and three primers and one topcoat (3P1T)—were applied to four types of FB substrates defined by layer and structural position. Adhesion, pencil hardness, and abrasion resistance were measured according to GB/T standards, complemented by surface roughness, contact angle, XPS, and SEM analyses. Results showed that substrate heterogeneity dominated coating behavior. The parenchyma-rich inner-layer internodes, characterized by higher polarity (O/C = 0.296) and rougher texture, exhibited stronger adhesion and superior abrasion stability, whereas the fiber-dense outer layer nodes, with lower polarity (O/C = 0.262), showed weaker bonding. Increasing the number of primer layers improved film continuity only when the substrate microstructure allowed sufficient primer penetration. The combined findings indicate that coating adhesion and wear stability are primarily governed by substrate composition and surface polarity rather than by coating thickness. These results provide scientific and practical guidance for optimizing primer application and surface preparation in the industrial finishing of bamboo-based decorative panels, while also highlighting the environmental and economic advantages of waterborne coating optimization for sustainable bamboo manufacturing. Full article

A novel bio-gelatin fiber-reinforced composite (BFRC) was first developed by incorporating industrial bone glue/gelatin as the matrix, magnesium oxide (MgO) as an additive, and natural or synthetic fibers as reinforcement. Systematic tests evaluated mechanical, impact, and thermal performance, alongside microstructural mechanisms. Results showed that polyethylene (PE) fiber-reinforced composites achieved a tensile strength of 3.40 MPa and tensile strain of 10.77%, with notable improvements in compressive and flexural strength. PE-based composites also showed excellent impact energy absorption, while bamboo fiber-reinforced composites exhibited higher thermal conductivity. Microstructural analysis revealed that coordination between Mg²⁺ ions and amino acids in gelatin formed a stable cross-linked network, densifying the matrix and improving structural integrity. A multi-criteria evaluation using the TOPSIS model identified the BC-PE formulation as the most balanced system, combining strength, toughness, and thermal regulation. These findings demonstrate that ionic coordination and fiber reinforcement can overcome inherent weaknesses of gelatin matrices, offering a sustainable pathway for building insulation and cushioning packaging applications. Full article

To quantitatively assess the environmental impact of producing a typical bamboo-based fiber composite material—bamboo scrimber (BS)—and to explore pathways for low-carbon optimization, this study adopts the Life Cycle Assessment (LCA) method with a focus on carbon footprint analysis. Using the actual production process of an enterprise as a case study, field data were collected and analyzed for bamboo scrimber with a nominal thickness of 1.5 cm. The results show that the carbon footprint of 1 m² of this product is 3.11 kg CO₂-eq, with the manufacturing stage contributing the highest emissions at 1.45 kg CO₂-eq. The primary source of carbon emissions is steam consumption, mainly occurring during the carbonization and drying of bamboo bundles. Therefore, optimizing these stages is crucial for reducing the overall carbon footprint of the product. This study provides a scientific basis for the sustainable development of bamboo-based fiber composite materials and offers practical recommendations for improving their environmental performance in production. Full article

Conventional methods for the synthesis of porous carbons are typically time- and energy-consuming and often contribute to the excessive accumulation of waste solvents. An alternative approach is to employ environmentally friendly procedures, such as mechanochemical synthesis, which holds great potential for large-scale production of advanced carbon-based materials in coming years. This review covers mechanochemical syntheses of highly porous carbons, with a particular focus on new adsorbents and catalysts that can be obtained from biomass. Mechanochemically assisted methods are well suited for producing highly porous carbons (e.g., ordered mesoporous carbons, hierarchical porous carbons, porous carbon fibers, and carbon–metal composites) from tannins, lignin, cellulose, coconut shells, nutshells, bamboo waste, dried flowers, and many other low-cost biomass wastes. Most mechanochemically prepared porous carbons are proposed for applications related to adsorption, catalysis, and energy storage. This review aims to offer researchers insights into the potential utilization of biowastes, facilitating the development of cost-effective strategies for the production of porous carbons that meet industrial demands. Full article

As wind turbine rotors grow in size and Greece advances its offshore wind energy initiatives, this study analyzes the structural behavior of offshore wind turbine blades using fluid–structure interaction (FSI) methods. The blade skin and shear webs of the International Energy Agency (IEA) 15 MW wind turbine, assumed to operate in the Aegean Sea, are examined. Computational fluid dynamics (CFD) simulations are conducted for two steady-state wind speeds based on local weather data, followed by finite element analysis (FEA) to assess advanced materials in terms of strength, cost, and carbon footprint. This is the first study to evaluate bamboo- and basalt-based composite materials under Greek offshore wind conditions using FSI methods. Bamboo composites are affordable and sustainable, but their limited durability reduces their viability in offshore environments. The simulation results indicate that using bamboo composites as blade skin may lead to damage due to the excessive loads on offshore wind turbine blades. In contrast, basalt fiber composites are also environmentally viable and offer superior strength, corrosion resistance, and long-term performance, making them a promising alternative. However, their naturally high density may impact the overall weight of the structure. This study concludes that offshore wind technology in the Aegean is feasible but remains costly and environmentally demanding. The further development and adoption of basalt fibers may serve as a gateway to more environmentally friendly offshore structures. Full article

Fully bio-based composites were obtained from continuous bamboo strips and flame-retardant polyamide 11 (PA11-FR) matrix. A mercerization treatment was performed on the bamboo strips surface to optimize fiber-matrix interactions. Composites were obtained by thermocompression molding with two pressure plateaus. The influence of the concentration of NaOH solution treatment was analyzed. The thermogravimetric analysis highlighted that the mercerization treatment removes part of hemicellulose, low molecular weight lignin and amorphous cellulose, while crystalline cellulose is preserved. Dynamic mechanical analysis performed in the shear configuration revealed the level of interactions between bamboo strips and PA11-FR matrix. The glassy modulus was improved for the composites compared to the matrix and their rubbery modulus was increased by a factor 4.6. Composites with bamboo strips treated at 1% NaOH showed the highest shear modulus across the entire temperature range with an increase by a factor of 1.39 on the glassy plateau and 1.3 on the rubbery plateau, with the untreated bamboo strips/polyamide 11-FR composite as reference. Water uptake was analogous for composites and bamboo strips, so the shear modulus at room temperature was not impacted by moisture. Full article