Characterization of potential cellulose fiber from Luffa vine: A study on physicochemical and structural properties

Enhancing Syagrus romanzoffiana lignocellulosic fibers' properties by ecological treatment with sodium bicarbonate for applications in sustainable lightweight biocomposites

Investigating the fascinating world of natural fibers, where Syagrus romanzoffiana fibers (SrFs) are promising substitutes for glass and synthetic fibers in composite materials, is more than interesting. The improvement of SrFs through an environmentally friendly treatment employing sodium bicarbonate (NaHCO₃) at different concentrations (5 %, 10 %, 20 %, and 30 % by weight) over various durations (24, 72, and 168 h) is the subject of this study. The objective is to provide a sustainable and economical approach to enhancing fiber characteristics. Comparisons were made between treated and untreated fibers and fibers from semi-arid and humid regions to evaluate geographical influences. Key findings include considerable enhancements in tensile properties: a 58 % rise in Young's modulus and a 69 % rise in traction stress for fibers treated with 20 % NaHCO₃ for 72 h. The stretching at fracture of these treated fibers was measured at 1.04 ± 4.49 %. The treated fibers also showed an increased crystallinity index of 71.61 % and a crystal size of 2.38 nm. Fourier-transform infrared spectroscopy revealed the chemical modifications from the treatment. Thermogravimetric analysis (TGA) indicated thermal stability up to 327 °C and a kinetic activation energy of 53.84 kJ/mol, compared to 62.72 kJ/mol for untreated fibers. The study highlights an environmentally friendly approach to material development by showcasing the potential of treated SrFs in lightweight biocomposite applications. This study provides valuable information on the TGA/pyrolysis of SrFs at 10 °C/min for potential bioenergy production, including assessing environmental impact, opportunities concerning sustainable resource management, and integration with other renewable energy systems.

Superelastic bamboo cellulose nanofiber based carbon aerogel with layered network microstructure for high sensitivity piezoresistive sensor

Carbon aerogels, characterized by their high porosity and superior electrical performance, present significant potential for the development of highly sensitive pressure sensors. However, facile and cost-effective fabrication of biomass-based carbon aerogels that concurrently possess high sensitivity, high elasticity, and excellent fatigue resistance remains a formidable challenge. Herein, a piezoresistive sensor with a layered network microstructure (BCNF-rGO-CS) was successfully fabricated using bamboo nanocellulose fiber (BCNF), chitosan (CS), and graphene oxide (GO) as raw materials. The fabrication process involved directional ice-crystal growth and mild hydrothermal reduction methods where the directional ice-crystal growth technique imparted a stable network-like pore structure, while the mild hydrothermal reduction method ensured electrical conductivity without compromising the original properties of the CNF. Taking advantage of the stress transfer properties of the cross-linked network structure, BCNF-rGO-CS exhibited exceptional reversible compressibility (sustaining 80 % strain), high fatigue resistance (10,000 cycles at 60 % strain), and high stress retention (84.6 %) over long-term cycling. Furthermore, the BCNF-rGO-CS sensor exhibited notable low-pressure sensitivity, excellent response time (66/76 ms), and it was capable of responding to ultra-low pressures of 10 Pa. Based on these favorable characteristics, the piezoresistive sensor holds promising prospects for applications in body motion detection, health monitoring, and flexible electronic-skin.

Characterisation of Bambara groundnut (Vigna subterranea (L.) Verdc.) shell waste as a potential biomass for different bio-based products

Efforts are ongoing to utilise agricultural waste to achieve a full resource use approach. Bambara groundnut is an important crop widely grown in the sub-Saharan Africa with potential future importance because of its resilience to thrive under heightened weather uncertainty and widespread droughts that have challenged food security. After harvesting, the edible nuts are separated from the shells which are discarded as waste. Therefore, this research is aimed at characterising the chemical composition and the structural properties of Bambara groundnut shells (BGS) in view of their potential application as a biomass for different bio-products. The chemical composition of BGS was found to be 42.4% cellulose, 27.8% hemicellulose, 13% lignin and 16.8% extractives. Proximate analysis showed a high amount of volatile matter (69.1%) and low moisture (4.4%). XRD analysis confirmed crystallinity of cellulose I polymer and FTIR analysis observed functional groups of lignocellulosic compounds. Thermal stability, maximum degradation temperature and activation energy were found to be 178.5 °C, 305.7 °C and 49.4 kJ/mol, respectively. Compared to other nutshells, BGS were found to have a relatively high amount of cellulose and crystallinity that may result in biocomposites with improved mechanical properties.

Extraction and characterization of a novel cellulosic fiber derived from the bark of Rosa hybrida plant

The current investigation aims to choose an alternate potential replacement for the nonbiodegradable synthetic fibers used in polymer composites. This goal motivated the thorough characterization of Rosa hybrida bark (RHB) fibers. The research explored fiber characterization such as morphological, mechanical, thermal, and physical properties. The suggested fiber features a percentage of cellulose, hemicellulose molecules, and lignin of 52.99 wt%, 18.49 wt%, and 17.34 wt%, respectively according to chemical composition studies, which improves its mechanical properties. It is suitable for lightweight applications due to its decreased density (1.194 gcm-3). The purpose of the Fourier transform infrared spectroscope was to observe and record how various chemical groups were distributed throughout the surface of the fiber. The presence of 1.41 nm-sized crystalline cellulose and further XRD analysis showed a crystallinity index of 75.48 %. Scanning electron microscope studies revealed that RHB fibers have a rough surface. According to a single fiber tensile test, for gauge length (GL) 40 mm, Young's modulus and tensile strength of RHB fibers were 6.57 GPa and 352.01 MPa, respectively, and for GL 50 mm, 9.02 GPa and 311 MPa, respectively. Furthermore, thermo-gravimetric examination revealed that the isolated fibers were thermally stable up to 290 °C and the kinetic activation energy was found to be 75.32 kJ/mol. The fibers taken from the Rosa hybrida flower plants' bark exhibit qualities similar to those of currently used natural fibers, making them a highly promising replacement for synthetic fibers in polymer matrix composites.

Hydrothermal Effect on Ramie-Fiber-Reinforced Polymer Composite Plates: Water Uptake and Mechanical Properties

Ramie-fiber-reinforced polymer composites (RFRP) have the advantages of low price and low energy consumption, but they have high hydrophilicity due to their special chemical composition. In order to study the effect of water absorption on the performance degradation of RFRP in a hydrothermal environment, the authors prepared RFRP sheets by compression molding. Manufactured composites were exposed to a hydrothermal environment with a temperature of 40 °C and a humidity of 50% RH, 85% RH and 98% RH to study the water absorption and diffusion, mechanical properties (tensile properties, flexural properties and shear properties) of the RFRP, and their mechanical properties after drying. The research shows that the equilibrium moisture absorption rate of RFRP is mainly affected by the ambient humidity. The moisture absorption and diffusion of ramie-fiber-reinforced polymer composites (RFRP) in a hydrothermal environment conform to Fick's law. Before reaching the moisture absorption equilibrium (1~2 weeks), the mechanical properties decline rapidly, and then tend to be flat, and the mechanical properties of the RFRP decrease significantly with the increase in humidity; the water molecules reduce the interfacial bonding performance and the modulus degradation degree of RFRP in the hydrothermal environment is greater than that of strength. After the samples were completely dried, the mechanical properties of the RFRP rebounded greatly, but less than the initial value, and the hydrothermal environment produced irreversible changes to the substrates.

Compressive Properties of Polyurethane Fiber Mattress Filling Material

There is an inevitable trend toward exploring new, environmentally friendly fibers that can be used as raw material for mattresses with moderate hardness and air-permeable characteristics. Ethylene-propylene side by side (ES), high-shrinkage fibers, and thermoplastic polyester elastomer (TPEE) chips were introduced into polyethylene glycol terephthalate (PET)/polybutylene terephthalate (PBT) chip by melt blending to modify PET/PBT fiber. The modified PET/PBT (hereinafter referred to as PLON) is more suitable for mattress filling material than PET/PBT. To explore the compressive properties of PLON cushion made of PLON fiber and expand the scope of the PLON cushion’s application, a layered hardness test, hardness classification test and variance analysis were used to comprehensively evaluate the surface hardness, core hardness, bottom hardness and hardness classification of the mattress made of PLON cushion. The conclusions are: (1) The materials of the support layer have a significant effect on the hardness grade S. The hardness of the mattress with PLON as the support layer is between the spring and the coir; (2) when PLON is used as the material of the support layer, it possesses higher supporting force than coir and the characteristics of light weight and high resilience, which coir does not have; it is also softer than a spring mattress. As cushion material, it provides higher support for mattresses than foam. Practical applications, densities and structure were clarified through the above research, with implications for broader applications for PLON blocks in mattress products.

Characterization of potential cellulose fiber from cattail fiber: A study on micro/nano structure and other properties

Exploration of the application prospects of cattail fibers (CFs) in natural composites, and other fields is important for the sustainable development of new, green, light-weight, functional biomass materials. In this study, the physical and chemical properties, micro/nano structure, and mechanical characteristics of CFs were investigated. The CFs have a low density (618.0 kg m^-3). The results of transmission electron microscopy and tensile testing data indicated that the cattail trunk fiber (CTF) bundle is composed of parenchyma cells and solid stone cells, demonstrating high specific modulus (10.1 MPa∙m³·kg^-1) and high elongation at break (3.9%). In turn, the cattail branch fiber (CBF) bundle is composed of parenchyma cells with specific "half-honeycomb" shape. The inner diaphragms divide these cells into the open cavities. This structural feature endows the CTF bundles with stable structure, good oil absorption and storage capacities. The chemical component and the Fourier transform infrared spectroscopy analyses show that the CFs have higher lignin content (20.6%) and wax content (11.5%), which are conducive to the improvement of corrosion resistance, thermal stability and lipophilic-hydrophobic property of CF. Finally, the thermogravimetric analysis indicates that its final degradation temperature is 404.5 °C, which is beneficial to the increase in processability of CFs-reinforced composites.

Compressive Properties of Green Velvet Material Used in Mattress Bedding

With the increasing awareness of environmental protection, Green Velvet Material (PLON), a renewable and environmentally friendly material, has been widely applied to mattresses. In order to improve the compressive properties of PLON, a series of experiments were carried out with special attention given to the compression deformation characteristics, support performance of the PLON blocks and its effective application in mattress products. The results are: (1) Average slopes of the load-deformation curves’ two phases are represented by K1 and K2, respectively. K1 is more sensitive to density changes that range from 30 kg/m3 to 50 kg/m3, while K2 is sensitive to density changes that range from 20 kg/m3 to 50 kg/m3. Their values increase with the rise of density; (2) 25% IFD, 40% IFD, 65% IFD, SF and IHF values are sensitive to density changes and they significantly increase with the rise of density. PLON blocks have excellent supporting properties and are considered to be comfortable according to American FPF Test Standard (ASTM-D3574-B1) when used in mattress bedding; (3) a PLON block density of 30 kg/m3 is preferentially selected for the softer type of mattress, while a PLON block density of 40 kg/m3 is preferentially selected for the harder type of mattress. The compression deformation characteristics and support performance of the PLON blocks were analyzed and the effective application of PLON in mattress products was explored through the above research.

Characterization of ligno-cellulosic fiber extracted from Atriplex halimus L. plant

Lignocellulosic fiber extracted from saltbush (Atriplex halimus L.) is characterized as reinforcement of composite materials. The morphological, physical, thermal and mechanical properties of fibers were addressed for the first time in this paper. The fibers were also subjected to chemical analysis. Stems were boiled in 0.5% sodium hydroxide (NaOH) or 10% sodium bicarbonate (NaHCO3). Optical and scanning electron microscopy images show an abundance of fiber in the form of thick-walled polygonal tubes. NaOH treatment yielded rough-surfaced fibers whereas the NaHCO3 treatment yielded smooth-surfaced fiber. Attenuated total reflectance Fourier transform infrared analysis revealed that NaOH treatment removed amorphous components. Based on x-ray diffraction, the crystallinity index increased from 55% to 57%. Thermogravimetry and differential scanning calorimetry showed that the fiber was thermally stable up to 220 °C and 235 °C with activation energies of 56 kJ/mol and 72 kJ/mol respectively for bicarbonate-treated and NaOH-treated material. In single-fiber tensile tests, the latter was stronger, with a Young's modulus of up to 19 GPa and tensile strength of 229 MPa.