Search

Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this study is to investigate the natural Luffa vine (LV) fiber to be effectively used as cellulose fiber reinforcing material for lightweight and decay-resistance composite materials. The physical, chemical, thermal, and morphological properties of the LV fibers, together with their microstructure are investigated. The test results conclude that the LV density, microscopic characteristics, and mechanical properties show that this crop is a lightweight (200–550 kg/m3) natural fiber with a porous structure and a high specific modulus (1.18–2.04 MPa∙ m3/kg). The chemical, X-ray diffraction and the Fourier transform infrared spectroscopy analyses indicate that the LV has a high lignin content (25.18%) and a relatively high relative crystallinity (37.18%) of cellulose, and it contains saponins, which increase its erosion resistance and hardness. The thermogravimetric analysis reveals that the fibers can stand up to 315.4 °C. Moreover, due to their kinetic activation energy of 63.9 kJ/mol, they can be used as reinforcement materials in thermoplastic green composites with a working temperature below 300°. • Luffa vine (LV) have a multi-level porous structure and a high specific modulus. • The presence of saponins help LV develop corrosion-resistant composites. • The LV lignin is mostly guajacyl lignin and only a small amount of syringyl lignin. • The LV thermal properties meet to a working temperature of composites below 300 °C. [ABSTRACT FROM AUTHOR]

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. • The cattail fiber (CF) has lower density and multi-cavity structure. • Higher wax content endows CF with lipophilic-hydrophobic potential. • The cattail branch fiber (CBF) has "half-honeycomb" shape and inner diaphragms. • The CBF structural feature gives CF stable structure and good oil storage capacities. • The cattail trunk fiber bundles exhibit excellent mechanical properties. [ABSTRACT FROM AUTHOR]

The exploration of modified luffa sponge (LS) cellulose fiber in the field of polymer composite can contribute to the development of high-performance and lightweight composites. In this study, two chemical treatments (10%NaOH–20%CH 3 COOH (Method 1) and 10%NaOH–5%Na 2 SO 3 (Method 2)) and two drying methods (air drying and freeze-drying) were used to treat LS. The microscopic characteristics and physical properties showed that Methods 1 and 2 caused shrinkage of the LS fibers and increased their fiber density by 30.6% and 15.0%. Meanwhile, freeze-drying kept the cells of modified LS fibers full and decreased their fiber density by 5.0% and 21.0%, respectively. The tensile properties test analyses indicated that freeze-drying further increased the elongation at break values of modified LS fibers by 25.3% and 17.7%, respectively. The moisture absorption analyses showed that freeze-drying could further decrease the moisture absorption ratios of modified LS fibers by 25.8% and 35.8%, respectively, which was useful for improving the dimensional stability of composite materials. Moreover, the thermogravimetric analysis reveals that freeze-drying increased onset degradation temperatures of the modified fibers by 24.0 °C and 6.7 °C, which was beneficial to improve the thermal stability of the composite material. • Freeze-drying can further decrease the water absorption of modified LS fiber. • Freeze-drying can further increase the toughness of modified LS cellulose fiber. • Freeze-drying can improve the thermal stability of modified LS cellulose fiber. [ABSTRACT FROM AUTHOR]

• Luffa vine (LV) is a low-density natural plant fiber with a porous structure. • The secondary wall of LV fiber cell contains two layers with spiral thickening. • Sclerenchyma cell of LV exhibits excellent micromechanical properties. • The microscopic characteristics endow LV with good processability. • The pit pairs on cell walls provide good permeability to LV fibers. The exploration of luffa vine (LV) in the polymer composites field can contribute to the development of lightweight composites and expand their use in new wide scale applications. In this study, the physical and chemical properties and the microstructure of the LV fibers were investigated by various techniques. The results of LV density and microscopic characteristics indicated that this crop is a lightweight (with density mainly concentrated in 0.30–0.45 g cm−3) natural fiber with a porous structure (the ratio of wall to lumen: 0.2–0.3). Transmission electron microscopy and nanoindentation analyses showed that the secondary wall of the LV sclerenchyma cell is made up of two layers with spiral thickening and exhibiting a high nanoindentation modulus (7.8–10.4 GPa) and a high nanoindentation hardness (0.40–0.58 GPa). The chemical composition and X-ray diffraction analysis indicated that the LV has high lignin content (20–25%) and a relatively high relative crystallinity index of cellulose, which are conducive to increase the hardness of the LV fiber. Moreover, microscopic characteristics analysis also revealed that the LV fiber cells have a relatively high aspect ratio (30.3), there are pit pairs on the LV fiber cell walls, and the core fiber cells of the LV have relatively high flexibility coefficient (0.8), which are beneficial to increase the processability of composite materials with the LV fibers as reinforcement. [ABSTRACT FROM AUTHOR]