Physicochemical and Thermal Properties of Ceiba pentandra Bark Fiber

Owing to their low weight-to-high strength ratio and recyclable features, the natural fibers are the most potential choice in place of synthetic fibers and been used as reinforcement materials in polymer matrix composites. Characterization of Ceiba pentandra bark fibers (CPFs) such chemical analysis, Fourier Transform-Infrared Analysis (FTIR), X-ray diffraction, thermogravimetric analysis, and Differential thermogravimetric analysis (DTG) analysis has analyzed. CPFs contain 60.9% (w/w) of cellulose, 17.5% (w/w) of hemicellulose, and 23.5% (w/w) of lignin. Besides, its density and crystallinity index are 682 kg m^?3 and 57.94%, respectively. TG and DTG analysis discovered that CPFs are thermally stable up to 342.1°C. Further, all the resources of CPFs ensured that it can be an excellent alternative for synthetic fibers in polymer matrix composites.     

Characterization of New Natural Cellulosic Fiber from the Bark of Dichrostachys Cinerea

The increasing environmental awareness has directed attention of the researchers towards the field of natural fiber composites. The aim of this investigation is to understand the physico-chemical properties of fibers extracted from the bark of the Dichrostachys Cinerea (DC) plant. Dichrostachys Cinerea fibers (DCFs) has cellulose (72.4 wt. %), hemicellulose (13.08 wt. %), lignin (16.89 wt. %), density (1240 kg/m³), crystallinity index (57.82%), and tensile strength (873 ± 14 MPa). Besides the cellulose degradation of DCFs at 359.3° vide by the thermo-gravimetric analysis and chemical groups are identified by Fourier transform analysis. Eventually the characterization results of DCFs strongly show the possibility of reinforcement in polymer matrices.     

Characterization of cellulosic fibers from Morus alba L. stem

The chemical microstructural, physical, and thermal properties of the Morus alba L. stem fibers (MAFs) are described for the first time in this work. By analyzing the results of chemical composition, it was observed that the cellulose content of the stem of MAFs is an acceptable value when compared with other fibers and showed better results. Due to their lightweight (1316 kg/m³) and the presence of high cellulose content (58.65%) with very little amount of wax (0.56%), they provide good bonding properties. In addition, analyzing the results of X-ray diffraction and Fourier transform infrared spectroscopy, we observe a degree of crystallinity of 62.06%, which is closely associated with the presence of crystalline cellulose, while the other components are amorphous. The diameter of the extracted cellulosic fibers was in the range 6–20 µm. Moreover, it was possible to identify the degradation step of each primary component of lignocellulosic fiber and to observe that it is thermally stable up to 216°C. The characterization results show that the MAF is a better replacement material for synthetic fibers because of its significant physical, chemical, and thermal properties.     

A new study on characterization of Pithecellobium dulce fiber as composite reinforcement for light-weight applications

ABSTRACT

A bio-fiber, Pithecellobium dulce is abundantly available in all over the world. It has a higher cellulose content (75.15 ± 0.26 wt.%) and low density (865 ± 26 kg/m³). To acquire fundamental knowledge about Pithecellobium dulce Fibers (PDFs), its physicochemical, crystalline, tensile, and morphological properties were examined and compared with other plant fibers. The chemical functional groups and crystallinity index (49.2 ± 2.45%) of the PDFs were obtained via Fourier transform-infrared analysis and X-ray diffraction, respectively. The Thermogravimetric analysis results of PDFs exhibit thermal stability up to 170°C. The surface morphology of PDF was analyzed by scanning electron microscopy. The attained results conclude that PDFs are appropriate fibers for acting as reinforcement in manufacturing of green composite product.     

Physicochemical Properties of New Cellulosic Fibers from Azadirachta indica Plant

This research study was aimed at examining newly identified natural fiber from the bark of Azadirachta indica (AI). The various properties were analyzed and compared with other available bark fibers. The chemical composition of Azadirachta indica fibers (AIFs), high cellulose (68.42 wt.%) content, and low lignin (13.58 wt.%) were discovered. The lower density of 740 kg/m³, and crystallinity index of 65.04% properties were identified. The maximum peak temperature obtained was 321.2 °C in Differential thermogravimetry (DTG) curve. Taken together, all the properties of AIFs indicated that they could be suitable to make green composites for various types of applications.     

Extraction and Characterization of Novel Natural Cellulosic Fibers from Pigeon Pea Plant

ABSTRACT

This study is mainly focused on the extraction and characterization of the lingo-cellulosic fibers from the Pigeon Pea plant. The chemical components of the fibers such as cellulose content (55.03%), lignin (18.32%), wax content (2.38%), moisture content (8.13%), and density (1.7389 g cc^?1) were identified. Functional groups present in the fibers were obtained by infrared spectroscopy. By using X-ray diffraction analysis, Crystallinity Index is found to be 68% and thermogravimetric analysis showed that thermal degradation of the fiber begins at 225°C.The results suggest that the Pigeon pea fibers can be used as reinforcement in polymer-matrix composites.     

Characterization of New Natural Cellulosic Fiber from Heteropogon Contortus Plant

Natural fibers are one of effective substitute for switching artificial fiber and concentrating to reinforce polymer matrixes due to their decomposable character. This study was implied to realize physico-chemical properties of bio fiber obtained from Heteropogon contortus (HC) plant. Heteropogon contortus fibers (HCFs) had cellulose (64.87 wt. %), hemicellulose (19.34 wt. %), lignin (13.56 wt. %), and low density (602 kg/m³). The chemical functional group of HCFs was established by Fourier transform infrared spectroscopy, thermal stability of the fiber up to 220°C discovered by thermogravimetric analysis. Further the assets of HCFs proved that it can act as an excellent reinforcement material as a bio composite. Finally, the tensile properties were carried out through single fiber tensile tests, such as tensile strength, tensile modulus and microfibrillar angle.     

Physicochemical,tensile, and thermal characterization of new natural cellulosic fibers from the stems of Sida cordifolia

Natural fibers are the one worthy substitute for replacing synthetic fibers and used as a polymer reinforcement due to their eco-friendly nature. This investigation deals with the newly identified Sida cordifolia fibers (SCFs) characterized by chemical analysis, single fiber tensile test, thermogravimetric analysis (TGA/DTG), Fourier transform-infrared spectroscopy (FT-IR) analysis, X-ray diffraction (XRD), and atomic force microscopy (AFM). The chemical constituents of SCFs contains cellulose (69.52%), hemicellulose (17.63%), and lignin (18.02. %). The SCFs are thermally stable up to a temperature of 338.2°C evidenced by TGA analysis. The X-ray diffraction confirmed that SCFs were rich in cellulose fraction with a crystallinity index of 56.92%.     

Characterization of a New Lignocellulosic Fiber from Brazil: Imperata brasiliensis (Brazilian Satintail) as an Alternative Source for Nanocellulose Extraction

The chemical, physical and thermal properties of a new lignocellulosic fiber from Brazil (Imperata brasiliensis) were examined by SEM, chemical composition, XRD, FTIR, and TGA. Fibers were analyzed aiming to compare the properties of its new natural resource with other lignocellulosic fibers used as a source of nanocellulose extraction. Microscopy analysis demonstrated that the bundle of fibers presented a variety of size and shapes, ranging between 25 and 500 µm, while a single fiber has a diameter of 5 µm. The chemical composition showed the presence of 37.7% of cellulose, 35% of hemicellulose and 14.3% of lignin. The total crystallinity index (CI) calculated using Segal method was of 36.6%. By TGA, it was possible to identify the degradation step of each primary component of lignocellulosic fiber and to observe that the onset degradation temperature was 157°C. With the results of ATR-FTIR technique, it was possible to estimate the CI, and the results exhibited good agreement with that calculated by XRD. Finally it was possible to conclude that fibers obtained from Imperata brasiliensis are suitable to be used as a resource for nanocellulose obtainment since presents almost the same properties of other lignocellulosic fibers successfully used in literature for nanocellulose extraction.     

Properties of Natural Fibers from the Abaxial Side of Fireweed (Gerbera delavayi) Leaf Blade for Manual Spinning

Natural plant fibers obtained from the abaxial side of fireweed (Gerbera delavayi) leaf blade were systematically studied. Fireweed fibers were manually dismantled from hot-bath-treated, refrigerated, or untreated leaves and evaluated for different properties. In terms of the collection method, treatment with hot bath exhibited the highest efficiency. As for chemical composition, that of raw (untreated) fireweed fibers was similar to that of cotton, except for wax content that was four times higher in fireweed fibers that in cotton fibers. Fireweed fiber generally exhibited low values of length (6.5 mm), fineness (0.5 dtex), tenacity (0.7 cN/dtex), density (0.9 g/cm³), and crystallinity (14.6%) but similar elongation at break and moisture regain to those of cotton. Furthermore, fireweed fibers showed a smooth surface, soft texture, and water impermeability. After hot-bath treatment, fibers showed 20% lower wax component but higher thermal stability than raw fibers. The small size hindered the fibers from achieving the desirable standard of spinning and weaving by modern machine, but these unique cellulose fibers can be used for manual textile application without any chemical treatment.     

Extraction and Characterization of New Natural Cellulosic Chloris barbata Fiber

Natural swollen finger grass fibers being novel are botanically known as “Chloris barbata fibers (CBFs)” and are selected for this study in order to understand their morphological properties. The CBF has higher cellulose (65.37 wt%) content and lower density (634 kg/m³). Crystallinity Index (CI) of CBF was calculated from X-ray diffraction studies and is valued as 50.29%. The surface of CBF was examined using a Scanning Electron Microscope (SEM) for observing the surface morphology. Structural characterization and Chemical functional group were confirmed by Fourier transform infrared spectroscopy (FT-IR). The thermal behavior of CBFs was determined using TG and DTG curves from Thermo gravimetric (TG) analysis. Findings show that the fiber has a semi-elongated nearly circular cross-sectional shape, the fiber diameter is between 180 and 200 μm. TG analysis revealed that these fibers are thermally stable until 210°C. Thus the characterization results confirm the possibility of using CBF for the manufacture of sustainable fiber reinforced polymer composite.     

Morphology,Structure, and Mechanical Properties of Natural Cellulose Fiber from Mendong Grass (Fimbristylis globulosa)

This study was to investigate the morphology, structure, and chemical properties of the Mendong fibers extracted from Mendong grass (Fimbristylis globulosa) in the form of raw and treated fiber by alkali-included chemical content and functional group and to evaluate the strength and properties of Mendong fibers compared with other natural fibers. These studies explore the chemical properties of the fiber including fiber composition and functional group by FTIR, mechanical properties of fiber, and the structural and morphological analysis of the fiber using SEM and XRD. The results showed that the chemical contents of Mendong fibers were 72.14% cellulose, 20.2% hemicellulose, 3.44% lignin, 4.2% extractive, and moisture of 4.2%–5.2%. Mechanical properties of the fiber were a strong character with tensile strength of 452 MPa, and modulus of 17 GPa. The structural properties of Mendong fiber such as crystallinity, crystalline index, microfibril angle, and crystalline size were 70.17% and 58.6%, 22.9°, and 14.3 nm, respectively. This fiber has competitive advantages compared with other natural fibers and can be developed further as a potential reinforcement of polymer matrix composites.     

Sonosynthesis of Microcellulose from Kenaf Fiber: Optimization of Process Parameters

Green composites using cellulose fibers as a reinforcement material provide a sustainable and renewable alternative to petroleum-based polymers. However, controlling the usage of chemicals and processing parameters to extract the cellulose could be sometimes difficult. Therefore, this study aims to optimize the conditions for extracting the microcellulose from kenaf fibers using central composite design (CCD), a statistical tool in design of experiments. Three factors and three levels were chosen for carrying out the analysis. The design was based on sodium hydroxide (NaOH) dosage, Sodium Chlorite (NaClO₂) dosage and sonication time as independent variables, while dependent variables were the fiber size and degradation point. Later, size responses were fitted using quadratic polynomial model and degradation responses using 2-factor interaction model (2FI). The R² values of 0.89 and 0.83 were obtained for the quadratic and the 2FI model, respectively. Further, surface morphology, thermal analysis, Fourier transform infrared (FTIR) spectroscopy and X-Ray diffraction (XRD) were also used for design validation. Optimal parameters for microcellulose extraction were found to be 0.15 g of NaOH at first stage, 4.6 mL of NaClO₂ at second stage, and 10 min of sonication during third stage.     

Effect of Alkali Treatment on Alfa Fibers Behavior

The object of this study is to characterize of Algerian Alfa (Esparto grass or Stipa tenacissima L), and also to examine the effect of chemical treatment on different properties of this fiber. The surface of the Alfa vegetable fibers was modified by alkali treatment in 5% (NaOH) aqueous solution for 2, 4, 6, 8, 16, 24, 48, and 72 h. The chemical, physical, and morphological properties of the Alfa fibers were investigated. The results show that the Alfa fibers are composed of 39% cellulose, 33% hemicelluloses, 20% lignin, and certain minerals (e.g., SiO₂, K₂O, and CaO). The alkali treatment of the fibers contributes to a decrease in the rate of moisture absorption and to an increase the crystallinity and stiffness. The processing time for adequate alkali treatment is observed at 6 h.     

Characterization of natural cellulosic fiber from Epipremnum aureum stem

The natural fiber Epipremnum aureum was extracted from its plant. E. aureum fibers (EAFs) were investigated by chemical analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and single fiber tensile test. Chemical analysis, FTIR, and X-ray analysis evidenced that these fibers has 66.34% cellulose content with crystallinity index of 49.33%. The thermogravimetric analysis reveals that EAFs can thermally withstand temperatures until 328.9°C. The morphology of the EAFs was observed by scanning electron microscope. It was established that the fiber can be utilized as reinforcement in polymer composites.     

Engineered invasive plant cellulose fibers as resources for papermaking

Seven fast-growing invasive plant species were harvested in Slovenia and tested for their valorisation potential in the pulp and paper industry with the aim of sustainable substitution of commercial cellulose fibres. Cellulose fiber materials were isolated by filtration after solubilizing extractives, lignin and hemicellulose in a kraft pulping process. The chemical structure was thoroughly studied, as well as the optical, morphological and mechanical properties. All examined species (Ailanthus altissima, Fallopia bohemica, Fallopia japonica, Rhus typhina, Robinia pseudoacacia, Rudbeckia laciniata and Solidago canadensis) contain relatively high amount of C6 polysaccharides (>?35%), have notable hemicellulose content (30–40%), low ash content (<?2%) and can be easily delignified, while manufactured natural fibers exhibit convenient morphology (fiber length 0.47–0.88 mm; width 14.4–20.9 μm), optical (ISO whiteness 19.0–36.0%) and mechanical characteristics (tensile index 18.0–58.0 Nm/g; tear index 0.8–4.1 mN m²/g; and burst index 0.5–2.4 kPa m²/g indices), which makes them applicable to sustainable paper production. The pulp yields varied between 34–44%, where both darker herbaceous and brighter woody fibers were morphologically comparable to typical hardwoods. According to the observed properties Robinia pseudoacacia and Rudbeckia laciniata seem to be superior raw material for commercial papermaking products. The ubiquitous invasive plants pose a huge potential for the circular economy, especially in terms of their cascade valorisation of biorefinery by the isolation and valorization of hemicellulose, sugars, and lignins into added-value aromatic and aliphatic building blocks. However, promising yield of cellulose fibers of decent morphology and mechanical properties are reported in this study.

     

How the surface wettability and modulus of elasticity of the Amazonian paricá nanofibrils films are affected by the chemical changes of the natural fibers

The use of natural resources for the production of nanostructured cellulosic films of high quality could reduce pollution and raw material costs for cellulose industry. This work provides innovative information about the use of Amazonian species not explored in studies involving the production of nanostructured films, as well as the evaluation of important characteristics that may be decisive for the destination of the product. The aim of this study was to modify Schizolobium parahyba var. amazonicum (paricá) waste fibers through alkaline (NaOH) and bleaching (NaClO₂) treatments for cellulose nanofibrils (CNFs) production and evaluate the characteristics of the nanofibrils and the surface as well as the mechanical resistance of the films obtained. The alkaline treatment was carried out with sodium hydroxide (5% NaOH solution (w/v); 2 h), while the bleaching was performed using sodium chlorite and glacial acetic acid (1.5 g NaClO₂; 10 drops of glacial acetic acid; 1 h). The treatments were performed in sequence, producing nanofibrils after alkaline treatment and after bleaching. Lignin content did not change with the alkaline treatment, but it significantly decreased with bleaching (from 26.1 to 6.8%). Hemicelluloses content decreased with the sequence of treatments. FTIR results showed that the mechanical defibrillation caused disruption of the fiber bonds. The temperature of thermal degradation observed in DTG analysis increased from the natural fibers (243 °C) to alkaline?+?bleached fibers (255 °C). The defibrillation process led to higher thermal stability of the alkaline?+?bleached nanofibrils in comparison to fibers. Moreover, films were prepared from the obtained CNFs and evaluated by the mechanical properties and surface contact angle. The mechanical properties showed values of 6.93?±?0.18 GPa for modulus of elasticity (MOE) for the films produced from material which was submitted to the bleaching treatment. The results highlighted a more hydrophobic surface of the film produced with the CNFs generated from the bleached fibers. The results of mechanical properties showed the superiority of the films produced from the alkaline?+?bleached fibers.     

Enhancing the flame retardant of polyethylene terephthalate (PET) fiber via incorporation of multi-walled carbon nanotubes based phosphorylated chitosan

Phosphorylated chitosan (PCS) were first deposited on the multi-walled carbon nanotubes (MWNTs) surface via chemical modification to obtain functionalized MWNTs-based PCS (PCS-MWNTs). Then, a series of PET fibers with MWNTs or PCS-MWNTs were prepared via melt spinning. The microstructure and molecular structure of PCS-MWNTs were characterized by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy. The morphological structures, mechanical, thermal, and flame-retardant properties of the PET fibers containing MWNTs or PCS-MWNTs were analyzed by FESEM, therogravimetry, differential scanning calorimetry, cone and electronic tension meter method. The results showed that MWNTs were coated with PCS. Compared to PET fiber, when the content of PCS-MWNTs was 0.9 wt.%, the PCS-MWNTs/PET fibers exhibited an efficient flame-retardant capacity, with the lower heat release rate and total release rate values of 81.03 kW/m² and 39.05 MJ/m², respectively, decreasing by 130.06 kW/m² and 11.87 MJ/m². The thermal stability of PCS-MWNTs/PET fibers strengthened, and the char residue increased from 7.21 to 13.52%. Compared to MWNTs/PET fiber, the crystallization property and tensile strength of PCS-MWNTs/PET fiber improved, because of the good dispersion and strong interface binding force with the PET fiber. Overall, the PCS layer endowed the MWNTs with good dispersion and flame-retardant characteristics.     

Dietary fibre extracted from different types of whole grains and beans: a comparative study

Dietary fibre (DF) from different whole grains and beans (quinoa, buckwheat, highland barley, pea and mung bean) was extracted by enzymatic action. The components, crystallinity and properties were comparatively studied. Furthermore, we evaluated correlations between DF components and their crystallinity, thermal, physicochemical and functional properties. Results showed quinoa DF had highest polyphenol (25.58 mg GAE per 100 g), pectin (4.68%) and cellulose (52.34%) contents, crystallinity value (CV, 30.24%), ΔH (185.53 J g⁻¹), water-holding capacity (WHC, 5.35 g g⁻¹), α-amylase activity inhibition ratio (α-AAIR, 13.34%) and glucose absorption capacity (GAC), but lowest protein content (9.78%) and T_p (163.05 °C). Mung bean DF had highest lignin content (33.56%), fat adsorption capacity (4.73 g g⁻¹), and T_p (176.25 °C), but lowest CV (15.26%) and ΔH (132.15 J g⁻¹). Correlation analysis showed cellulose content had positive linear correlations with CV, ΔH, WHC, α-AAIR and GAC, but a negative correlation with T_p. The structure and properties of DF are largely attributed to cellulose content.     

Quality Attributes of Fruit Bar Made from Papaya and Tomato by Incorporating Hydrocolloids

Fruit bar was prepared from blend of ripe papaya and tomato pulps (variety, Red Lady and C.V. Naveen, respectively) in the ratio 75:25 on weight basis. Effects of hydrocolloids viz. pectin (P), starch (S), and ethyl cellulose (EC) and its three different levels on physico-chemical, sensory, and textural characteristics were investigated. It was found that seven different samples of fruit bar had moisture contents of 20.9–22.1% and total soluble solids 78.1–78.8°Brix while pH, browning index, and vitamin C contents were in the following ranges, 4.3–4.50, 0.137–0.150 (OD), and 40.5–41.4 mg/100 g respectively. Texture study revealed that hydrocolloids incorporation at 1% each of starch + ethyl cellulose and pectin + starch, 1.5% each caused significant (P < 0.05) increased in compactness/hardness of texture. Sensory characteristics study revealed that all the samples of fruit bar were acceptable in taste, color, and aroma but differed significantly (P < 0.05) in their texture. The samples packed in LDPE bags (100 μ), stored at 35–45°C for four months. It was found that there were significant (P < 0.05) changes in physico-chemical properties like acidity and vitamin C during four months storage. No significant (P < 0.05) effect on either browning index (OD) or deterioration in color, taste, and aroma of these samples was observed. During four months storage change in color and texture were not uniform for all treatments. Addition of 0.5 and 1% of each starch + ethyl cellulose were effective in maintaining the color while 0.5, 1, and 1.5% of each P + S was effective in improving the texture during four months storage.