Mechanical and Thermal Properties of Nanoclay-Treated Banana Fibers

The objective of this work is to improve the thermal, mechanical and fiber-matrix adhesion properties of banana fibers using nanoclay particle infusion. The nanoclays were infused into the banana fibers by using alkaline and silane chemical treatments. The morphology and distribution of nanoclays in banana fiber was examined by scanning electron microscopy. Nanoclay infused fiber resulted in 35.7% and 12.5% increased tensile modulus and strength over untreated fiber, respectively. Thermogravimetric analysis of nanoclay infused banana fiber shows ~ 2.2 times increased weight gain at 600°C when compared with untreated banana fiber.     

Stimulation of glucose uptake by Musa sp. (cv. elakki bale) flower and pseudostem extracts in Ehrlich ascites tumor cells

BACKGROUND: Glucose uptake study plays a major role in diabetes research. Impaired glucose uptake has been implicated in the development of hyperglycemia during diabetes. Banana plant is known for its anti‐diabetic properties and our earlier report revealed that banana flower and pseudostem of Musa sp. cv. elakki bale is beneficial during diabetes in rat models. The present study was designed to evaluate the potential effect of banana flower and pseudostem extracts on glucose uptake in Ehrlich ascites tumor (EAT) cells using 2‐[N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl)amino]‐2‐deoxy‐D ‐glucose (2‐NBDG), a fluorescent analogue of 2‐deoxyglucose. RESULTS: Methanol and aqueous extracts of banana flower and pseudostem were more potent in promoting glucose uptake in EAT cells, in comparison to acetone and ethanol extracts. At 20 µg dosage, highest net glucose uptake was observed in aqueous extracts of banana flower (18.17 ± 0.43 nmol L^?1) and pseudostem (19.69 ± 0.41 nmol L^?1). Total polyphenol content was higher in methanol (9.031 ± 0.036 g kg^?1) and aqueous (6.862 ± 0.024 g kg^?1) extracts of banana flower compared to pseudostem, which were 0.442 ± 0.006 and 0.811 ± 0.011 g kg^?1, respectively. CONCLUSION: Banana flower and pseudostem extracts are able to promote glucose uptake into the cells, presumably through glucose transporters 1 and 3, which could be beneficial in diabetes. Glucose uptake is likely promoted by phenolic acids besides other bioactives. It can be hypothesized that consumption of nutraceutical‐rich extract of banana flower and pseudostem could replace some amount of insulin being taken for diabetes. Copyright © 2011 Society of Chemical Industry     

Effect of Extraction Methods on the Properties of Althea Officinalis L. Fibers

In this study, the effect of extraction methods on the properties of Althea officinalis l. (marshmallow) fibers was investigated. For this purpose, obtaining the fibers from stem was done by water and chemical extraction. After the extraction process, mechanical and thermal properties of althea fibers were investigated and morphological structure was examined. Crystallinity indexes (CI) of fibers were determined. Scanning electron microscopy results revealed that extraction of althea officinalis fibers by alkali boiling in 5% NaOH solution led to removal of surface impurities and also according to X-ray diffraction results, crystallinity index of fibers was improved by 14%. Chemically extracted fibers showed 37% higher tensile strength when compared to water extracted fibers. Density measurements revealed that chemically retted fibers have higher density. Also, Fourier Transform Infrared Spectroscopy analysis showed that chemical extraction caused change of chemical composition by decreasing and/or disappearing of some peaks which belong to hemicellulose and lignin.     

Screening and identification of Acinetobacter junii for Apocynum vernetum L. fiber enzymatic retting

There are many kinds of ketones with antisepsis functions in the Apocynum vernetum L. fiber (ALF), but its enzymatic retting is difficult. In order to select the appropriate ALF enzymatic retting strain, wastewater from ALF retting was analyzed to screen a strain with high pectinase activity. Of the analyzed strains, the maximum pectinase activity measured was of the #2 strain: 103.2 IU/ml at a zymogenic time of 12 hrs at 37°C. The retting experiments verified that this strain was well suited for ALF; the residual gum rate of ALF was 15.26% and its fiber physicochemical properties were similar to those fibers which were chemically retted. The strain was determined to be a new retting strain, Acinetobacter junii, according to a 16S rDNA sequence analysis in combination with morphology, and biophysical and biochemical tests using fermentation, catalase, methyl red and gelatin liquefaction. As a new pectinase‐producing strain, Acinetobacter junii could be utilized in industrial enzymatic retting productions after further process optimization and can replace the conventional chemical retting process due to its improved fiber quality and reduced environmental pollution.     

Natural Fibers from Plantain Pseudostem (Musa Paradisiaca) for Use in Fiber-Reinforced Composites

Agricultural crops from plantain produce a significant amount of wastes and they are currently considered worthless. Accordingly, in this study, non-wood fibers from pseudostem of plantain plants were extracted through mechanical processing to be used as reinforcing material in polyester composites. Bio-based composites were obtained using a 4% wt. of lignocellulosic reinforcement and were prepared after the fibers underwent alkaline and acetylation treatments in order to enhance the compatibility of organic loads with the polyester matrix. The higher cellulose content of plantain fibers indicates that they can be used to reinforce composites with a polymeric matrix. The plantain fibers have bast fiber bundle of around 120 µm; single fibers of around 5 µm; and mesofibers with a diameter between 0.5 and 1 µm. The results showed that plantain fibers can be used as a filler material to obtain an alternative polymer composite. The flexural strength of composites (polyester with acetylated plantain fibers) was improved 28% when the properties are compared to control composite.     

Physicochemical Nature of Banana Pseudostem Starch

SUMMARY: Starch was isolated from banana pseudostem and its properties were compared with those of potato, corn and tapioca. The starch granules are irregular in shape and are bigger in size than those of the fruit starch. At 60°C, the granules start to swell, gradually increase in size, attain their maximum size at 75°C and do not rupture even after heating to 100°C. The intrinsic viscosity of the starch (2.05) is similar to that of potato starch (2.00). The amylose content of the starch compares well with that of banana fruit and potato (tuber) starch (21%). In general, banana pseudostem starch resembles potato starch.     

Progress in Enzyme-Retting of Flax

Abstract

New methods for retting flax are sought to overcome problems in the current method of dew-retting of flax. Published data are reviewed and new data presented on the development and testing of a method to ret flax using pectinase-rich enzyme mixtures plus chelators based on cost and fiber yield and properties. In spray enzyme retting (SER), flax stems are crimped to physically disrupt the plant's protective barrier and then sprayed until soaked with, or briefly immersed in, an enzyme/chelator formulation. Flax is then incubated at temperatures optimal for enzyme activity, washed, and dried. Pilot scale tests, conducted with 10 kg samples of flax retted with a series of formulations, showed that this method effectively retted flax stems from a variety of sources, including fiber flax, mature fiber flax, and linseed straw. Fiber yield, strength, and fineness were significantly influenced by variations in enzyme-chelator amounts. Cellulases inpectinase mixtures appeared to preferentially attack dislocations in fibers and fiber bundles resulting in loss of fiber strength. Polygalacturonases alone effectively separated fiber from non-fiber components. The SER method proved to be an effective framework for further tests on enzyme-chelator formulations that now must be integrated with physical processing to optimize the extraction of flax fibers based on cost and fiber yield and properties.     

Extraction and Characterization of Calotropis gigantea Bast Fibers as Novel Reinforcement for Composites Materials

The aim of this study is to scrutinize the use of Calotropis gigantea bast fibers as potential reinforcement in polymer composites. The bast fibers were extracted from the Calotropis gigantea plant bark and some of them were treated with alkali (5 wt.%) solution. The chemical composition, physico-chemical structural properties of the untreated and the alkali treated Calotropis bast fibers were studied. The results of chemical composition analysis indicated that alkali treatment removed most of the non-cellulose materials as confirmed by the FTIR analysis. The X-ray diffraction results exhibited that the crystallinity index of the alkali treated fibers increased in comparison with the untreated fibers, which agrees with the results obtained in the mechanical tests. The tensile strength and modulus of the alkali treated fibers were found to be higher whereas the elongation at break was lower than the untreated fibers. Thermal stability of alkali treated fibers was lower than that of the untreated fiber. Scanning electron micrographs showed roughening of the surface of the fiber due to the removal of the surface impurities and non-cellulosic components on alkali treatment.It can be concluded that alkali treatment is an effective method to improve the surface and mechanical properties of Calotropis bast fibers to be used in composite materials.     

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.     

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.     

Insitu Self-Assembly of Bacterial Cellulose on Banana Fibers Extracted from Peels

ABSTRACT

In this research work, in-situ self-assembly approach was used the first time, to cultivate bacterial cellulose on the surface of fibers, extracted from banana peels. The characterization was performed using SEM, FTIR, and single fiber tensile test in order to determine the surface morphology and mechanical properties of modified fibers. As-prepared hybrid fibers exhibited comparatively better mechanical properties, which can be attributed to the self-assembly of bacterial cellulose on banana fibers’ surface. Overall, this research work suggests a novel route for fiber extraction from banana peels and to use them for the preparation of bio nano-composites with improved mechanical properties.     

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.     

Evaluation and Impact Factors of the Mechanical Properties of Phloem Bundle Fibers Obtained from Kenaf Germplasm

The mechanical properties of kenaf phloem bundle fibers are valuable for reinforced composites or boards, more so than similar materials also used in textile or papermaking applications. 55 kenaf germplasm studied here showed an average phloem bundle fiber tensile strength of 643.6 MPa and an average elastic modulus of 23.3 GPa after chemical retting treatment. 19 of these kenaf germplasm had fiber tensile strengths >700 MPa, which can be attributed to intensive breeding programs. The fiber tensile strength and elastic modulus of kenaf germplasm had a significant positive correlation, but there was no such correlation between a fiber’s mechanical properties and its diameter or agronomic characteristics. Among 56 hybridized combination F₁ generations, the highest tensile strength was 928.3 MPa from a combination of No.30 of Xinan Wuchi × Guatemala 4. Therefore, breeding and screening are both useful for improving the mechanical properties of kenaf phloem bundle fibers. However, the effects of the used bundle fiber preparation method or cultivation year on the fiber’s mechanical properties were more pronounced than those of the type of kenaf germplasm or breeding operation used. The mechanical properties of kenaf phloem bundle fibers treated by chemical retting were superior to those treated using natural retting.     

Microstructural Study,Tensile Properties,and Scanning Electron Microscopy Fractography Failure Analysis of Various Agricultural Residue Fibers

This paper presents an approach to examine the microstructural properties and mechanical behavior of coconut husks, banana pseudo-stem, pineapple leaf, and sugarcane bagasse fibers by scanning electron microscope and mini-tensile tester, respectively. Single fiber bundles were examined by using scanning electron microscope. Tensile tests were performed at different diameters (0.15–0.55 mm) and gauge lengths (10, 15, 20, and 30 mm/min) to assess the effects of diameter and gauge length on tensile properties. It was found that fibers consisted of different types of regularly arranged cells. The tensile strength (310 MPa) and Young’s modulus (7.4 GPa) of pineapple leaf fiber bundles showed the highest value compared to the other fibers. The tensile strength and Young’s modulus decreased with the increase of diameter and gauge length of fiber bundles. Scanning electron microscopic fractography analysis showed comparatively heterogeneous ruptures associated with more participants of microfibrils for pineapple leaf and banana pseudo-stem fibers compared to coconut husk and sugarcane bagasse fibers. These fractographic observations were discussed in the light of current knowledge of the microstructure of each fiber and the corresponding mechanical properties.     

Evaluation of Structural,Tensile and Thermal Properties of Banana Fibers

Recognizing the importance of properties of the plant fibers for their use in polymeric composites and nonavailability of data on tensile, thermal, and other properties of banana fibers of Karnataka (India), a study was undertaken with the objective of determining some of these properties. This article presents determination of structural aspects of the fibers by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques; obtaining stress-strain curves and tensile properties by tensile testing; finally, thermal properties by differential scanning calorimetry and thermogravimetric analysis. FTIR spectrum of banana fibers showed aromatic character, while XRD results indicated the fiber to have mainly the cellulose I structure and crystallinity index of 52%. Thermal-degradation details of fiber samples were revealed by thermal studies. Stress-strain curves of banana fibers suggested their brittle nature with moderate values of tensile strength, but low percentage elongation. Weibull analysis of obtained tensile strength values revealed variation of “characteristic strength” values from 3800 MPa at 99% reliability to 22,700 MPa with 0.01% reliability. Morphology studies revealed the number of defects along the length of the fiber, while fractured surface exhibited flat surface with intracellular fractures clearly indicating brittle nature of the fiber.     

Effectiveness of Alkali and Sodium Bicarbonate Treatments on Sugar Palm Fiber: Mechanical,Thermal, and Chemical Investigations

ABSTRACT

Sugar palm fiber (SPF) as one of the attractive natural fibers to reinforce matrix is gaining attention. This is largely due to its similar properties when compared with other established natural fibers. The aim of this study is to investigate the effectiveness of sodium bicarbonate as a treatment chemical for SPF in comparison with established alkaline treatment. Both treated and untreated fibers were characterized and it was found that the treated fiber shows an increase in crystallinity, thermal stability, and surface’s roughness when compared with the untreated. Among the two different treatments, SPF treated with alkali has an initial decomposition temperature of 255.47°C, while sodium bicarbonate treated and untreated fibers have 250.19°C and 246.76°C, respectively. In both cases, the thermal stability of the fiber was improved. Also, as revealed by the X-ray diffraction (XRD) analysis, the crystallinity index of SPF treated with alkali and sodium bicarbonate increased by 18.43% and 13.60%, respectively, when compared with untreated fiber. In conclusion, the investigation proved that treatment with the sodium bicarbonate has a significant effect on the physicochemical properties of SPF and the chemical could be an alternative chemical for treating other cellulose fibers.     

Enzyme-Retted Flax Using Different Formulations and Processed Through the USDA Flax Fiber Pilot Plant

SUMMARY

Mature Ariane flax was retted with various proportions of the commercial enzyme mixture Viscozyme L (0.05, 0.1, 0.2, and 0.3% of product as supplied) and ethylenediaminetetraacetic acid (4,7, and 18 mM) from Mayoquest 200. Retted material was then cleaned through the USDA Flax Fiber Pilot Plant (Flax-PP) consisting of the following: 9-roller crushing colander, top shaker, scutching wheel, and 5-roller grooved colander. To simulate cottonization of fiber for use in textiles, the Flax-PP-cleaned fiber was passed 1 × through a Shirley Analyzer. Fiber yields and properties (strength, elongation, fineness, and color), which were determined for the various processing stages, were influenced by various formulations and by processing stage. For this flax sample, 0.05% Viscozyme plus 18 mM EDTA produced the highest yield of Flax-PP and Shirley-cleaned fibers, strong fine fibers of light color, and the strongest coarse fibers from Shirley by-product material.     

Foam-Mat Drying of Plantain and Cooking Banana (<Emphasis Type="Italic">Musa</Emphasis> spp.)

Foaming, reconstitution, and sensory attributes of foam-mat-dried plantain and cooking banana were investigated. Plantain and cooking banana pastes mixed with different concentrations (0.005%, 0.01%, 0.015%, and 0.02%) of glyceryl monostearate (GMS) were whipped, and the resulting foams were air dried at 60°C, 70°C, and 80°C. Physical, chemical, and sensory properties of fresh and reconstituted paste from plantain and cooking bananas were determined. Higher GMS concentration and longer whipping time resulted in lower foam densities. Generally, cooking banana foams showed lower foam density compared to plantain foam. Lower drying temperatures and concentration of GMS resulted in longer drying time. pH (4.41–4.80), titratable acidity (0.06–0.08), and water absorption capacity (56.75–64.02%) of the reconstituted pastes varied with commodity, drying temperature, and %GMS concentration. Fresh and reconstituted pastes showed comparable physical and chemical attributes, while the taste and sensory attributes of fresh plantain and cooking banana pastes were significantly (p < 0.05) better than those of reconstituted pastes.     

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.     

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.