Luffa Fiber Research Articles

Effect of gamma irradiation on mechanical properties of poly (lactic) acid–luffa fiber composites

Modification of surface of natural fiber by gamma irradiation is an effective and economical technique and of viable interests in the terrain of biocomposites. The response of doses (0.5 Gy,1Gy and 2 Gy) of gamma irradiation of 6MV energy on the structural, tensile and flexural properties of composites using poly lactic acid (PLA) and fibers of luffa cylindrical (LC) is studied. Preliminary results suggests promising mechanical properties. After reinforcement of irradiated LC fiber, the tensile strength and flexural strength of the virgin PLA matrix increases by 60% and 155% respectively. The E-modulus of the composites are also heightened with addition of irradiated fiber up to the limit of 1 Gy of irradiation dose and then decreases with higher dose of irradiation. Furthermore the tensile strength and flexural strength of the composites increases with incorporation of very low content of LC fiber up to 2wt% and decreases with higher loading of fibers (5wt% and 10wt%). Modulus of composites is enhanced with increase in wt of fiber content in the composites. Moreover beefore reinforcement the LC fibers are modified with Ca salts in order to explore the use of these composites in biomedical territory. Copyright © 2018 VBRI Press.

Mechanical Properties of Luffa Cylindrica and Coconut Coir Reinforced Epoxy Hybrid Composite

Abstract: In the current day scenario all the researchers and engineers are searching for a better and cheaper alternative for the current engineering materials. The project deals with the low cost, light weight and biodegradable composites and their use in the current industries. Substituting the legacy fiber reinforced composites with the low-cost natural plant- based fibers reinforced composites help us achieve comparative mechanical properties. India has a quite rich source of natural plant-based fibers which can be used for the production of natural fiber reinforced composites. In this project we used a combination of luffa fibers and coir fibers to produce an epoxy hybrid composite. The current project explores two different problems related to the natural fiber reinforced hybrid composite: 1) Study of mechanical properties of the hybrid thermosetting composite. 2) Study of possibilities of use of natural fiber reinforced epoxy hybrid composites in the different industries

Correction to: Effects of luffa and glass fibers in polyurethane-based ternary sandwich composites for building materials

Correction to: Effects of luffa and glass fibers in polyurethane-based ternary sandwich composites for building materials

Application of alkaline MnP immobilized Luffa fibers in mixed azo dyes degradation

The dying of textiles, foods, tablets, and cosmetics has gained importance as they are attractive and colorful. These dyes vary in their physical and chemical properties. These dyes are resistant to stresses and are carcinogenic and mutagenic. The release of reactive azo dyes into the environment poses a great threat to living organisms. The treatment of the reactive azo dyes gained limelight by the implementation of conventional techniques. Despite the advantages, these methods are expensive and produce secondary sludge, thereby increasing the toxicity—the eco-friendly application of microorganisms surviving in the reactive azo dye contaminated sites. The alkaliphiles thrive in the higher alkaline environment by utilizing azo dyes as the sole carbon source and producing enzymes. The cleavage of the complex azo dyes is aided by azo-reductase, laccase, and peroxidases. The degradation of the mixed azo dye using Manganese Peroxidase enzyme produced by an alkaliphilic bacterial strainPseudomonas mendocinaThe optimum temperature (60 °C) showed 3.76 U/mL and 1.67 U/mL at alkaline pH. The enzyme activity (1.4 U/mL) was immobilized in the luffa fibers of the fruit Luffa aegyptiacawas employed in the mixed azo dyes degradation. The degradation was further analyzed using HPLC and GC–MS.

Noise Reduction Analysis through Biomaterial Based Acoustic Material

With development of smart technical applications many devices and technology are involved to resist the high intensity surrounding noise. High persistence of different noise in environment and living surrounding of human being is a challenging problem now days. Though the different technology and devices are invented to resist the noise level in the living surrounding but still it needs the development of more effective and potential materials. Luffa cylindrical fibre reinforced epoxy composite has significantly enriches this noise reduction property due to its unique and complex networking structure between the each of its single fibre. When a number of multilayered luffa cylindrical fibres reinforced with high sensitive polymer matrix like epoxy, their structural configuration modifies into that extent where the composite can be functioned as effective shielding material for propagation of sound through them. Ultrasonic blended alcohol with tartaric acid plays a significant role for enhancing sound absorption coefficient in addition with strengthening the material by interlocking the luffa fibres with polymeric matrix which is found to be increased significantly with that of alcohol blended chemicals. The SEM and FTIR characterization of both untreated and treated luffa fibre confirms the surface modification which enables the composites to be a good acoustic material. Further, thermal insulation properties are well confirmed and support the attenuation of sound propagation through the material which decreases the thermal and electrical conductivity of the composites.

Fabrication of novel carboxyl and amidoxime groups modified luffa fiber for highly efficient removal of uranium(VI) from uranium mine water

Novel luffa cylindrica adsorbent modified with carboxyl and amidoxime groups is successfully prepared by a simple water bath method for effective U(VI) uptake from uranium-containing wastewater and real uranium mine water. The critical factors affecting U(VI) adsorption are explored, such as grafting time of carboxyl and amidoxime groups, solution pH, initial concentration of U(VI) and contact time. The results show that LC-CA2-AO4 obtained under optimal condition possesses outstanding adsorption performance to U(VI) (qmax, 399.1 mg g−1). Repeated adsorption/desorption experiments display that LC-CA2-AO4 can be efficiently regenerated by 0.50 mol L−1 HCl solution and reused for uranium adsorption. Adsorption capacity and desorption efficiency of LC-CA2-AO4 to U(VI) drop slightly after eight cycles of regeneration test. The accordance of kinetic data with pseudo-second-order kinetics model suggests that the adsorption reaction is controlled by chemical process. Moreover, LC-CA2-AO4 displays high removal rate to U(VI) in real uranium mine water. Based on this work, it is demonstrated that LC-CA2-AO4 would be a promising candidate for potential application in field of uranium adsorption.

Investigation of the Sound Absorption and Transmission Loss Performances of Green Homogenous and Hybrid Luffa and Jute Fiber Samples

In order to promote the use of natural fibers in noise and vibration applications, the properties of these structures should be fully identified. The sound absorption coefficients (SACs) and transmission losses (TLs) of green luffa fiber samples are thoroughly investigated and their acoustic performances are compared with the acoustic performances of green homogenous jute and hybrid jute/luffa fiber samples in this study. For this purpose, green homogenous luffa and jute fiber samples and their green hybrid fiber samples with different thicknesses (10, 20, 30, and 40 mm) are produced and their SACs and TLs are determined using the impedance tube method. First, the methods for the experimental identification of acoustic properties are presented and the variations in the measured acoustic properties are identified. After that, the effects of sample thickness on the acoustic performances of homogenous luffa as well as jute samples and their hybrid fiber samples as a function of frequency are explored. The thickness-dependent tendencies of the SACs and TLs of homogenous and hybrid luffa and jute fiber samples for low, medium and high frequency ranges are determined. Then, the acoustic performances of the homogenous and hybrid luffa and jute samples are compared and evaluated. The results and analyses for the acoustic properties of homogeneous luffa and jute fiber samples and their hybrid fiber samples for a variety of thicknesses and different frequencies presented here can be used to design homogenous as well as hybrid luffa and jute fiber structures in practical applications.

An Experimental Investigation of Marble Dust in Luffa Fibre Reinforced Concrete

Typically, Concrete mixture is firm in Compression yet sickly in Tension and shear. Reason for this examination is to discover the conduct of cement built up with half-breed full-scale strands. By adding Luffa strands in rates like 0.5%, 1%, 1.5%& 2% to the solid, the mechanical properties are researched. The ideal level of Luffa fiber was discovered to be 1%. Marble has been generally utilized in structures since old occasions. The current examination is pointed toward using waste marble dust (WMD) in development industry itself as fine total in solid, supplanting characteristic sand and furthermore by adding the ideal level of Luffa fiber. The substitution is done halfway and completely in the different extents like 0%, 20%, 40%, 60% and 80% and its impact on properties of cement were examined. The ideal level of the solid by adding 1% of Luffa fiber and the extents was discovered to be 20%

Amide and phosphate groups modified bifunctional luffa fiber for highly efficient removal of U(VI) from real uranium wastewater

In this study, the natural luffa fiber was easily modified by chemical method with amide groups and phosphoric acid (LF-A2-M1/P). SEM, XRD, FTIR and XPS were used to characterize the morphology, structure, and property of the fiber. The maximum adsorption capacity of LF-A2-M1/P towards U(VI) is 353.85 mg·g−1 (pH = 6). The thermodynamic parameters demonstrate that the adsorption of functional fibers to U(VI) is a spontaneous process. It is worth noting that LF-A2-M1/P has excellent removal amount for U(VI) in the real uranium wastewater. Our study provides some new insights into the purification of uranium-containing wastewater by the modified natural fiber.

Synthesis, characterization and environmental application of an original adsorbent: polyaniline-coated luffa cylindrica

The coating of the fibrous skeleton of luffa cylindrica (LC) with polyaniline (PANI) was carried out by in-situ polymerization of aniline. A thin PANI layer in its emeraldine-salt form (ES) got bound on to the LC surface, as revealed by the green color the latter developed, procuring more roughness to the luffa fibers. The surfaces of both materials, i.e. the purified original luffa (LC) and the PANI-coated luffa (PANI/LC) were characterized by FTIR, completed by the Raman range, SEM/EDX and XRD. In particular, the presence of N–H moieties in the FTIR spectrum and the appearance of the following bands: C = N stretching of the quinoid di-imine units, C = C stretching of the quinoid ring and C–N.+ band of the radical-cation in the Raman spectrum confirmed the effectiveness of the coating of LC. Dedoping, as determined by solid addition method, completed at around pH 9.5. After characterization, PANI/LC was tested for its capacity to adsorb hexavalent chromium anionic species. First, the emergence of the chromium characteristic peak in the EDX spectrum brought experimental evidence for the effective sorption of chromium onto the PANI/LC surface. Then, the novel material displayed a high efficiency to retain the metallic pollutant, going up to ~ 300 mg.g−1. Thus, after the PANI-grafting, this light and cheap agricultural by-product should compete advantageously with commercial anionic exchangers, at least in terms of efficiency. Besides, adsorption parameters were examined. The Cr(VI) uptake process was found to follow second order kinetics, with a pseudo-second order rate constant equal to 0.7144 × 10–3 g.mg−1.min−1. At the lower end of concentrations, the adsorption efficiency decreased with increasing temperature. The computed thermodynamic parameters (namely ΔH°, ΔS° and ΔG°) indicate that adsorption is exothermic, with an unfavourable entropy change, and confirm its spontaneity. None of some classical models fitted the equilibrium sorption data, a result that expresses the sorption mechanism complexity.

Biodegradation mechanisms of sulfonamides by Phanerochaete chrysosporium – Luffa fiber system revealed at the transcriptome level

The overuse of antibiotics and subsequent enrichment of antibiotic resistant microbes in the natural and built environments is a severe threat to global public health. In this study, a Phanerochaete chrysosporium fungal-luffa fiber system was found to efficiently biodegrade two sulfonamides, sulfadimethoxine (SDM) and sulfadizine (SDZ), in cow urine wastewater. Biodegradation pathways were proposed on the basis of key metabolites identified using high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (HPLC-QqTOF-MS). Transcriptomic, metabolomic, and free radical analyses were performed to explore the functional groups and detailed molecular mechanisms of SDM and SDZ degradation. A total of 27 UniGene clusters showed significant differences between luffa fiber and luffa fiber-free systems, which were significantly correlated to cellulose catabolism, carbohydrate metabolism, and oxidoreductase activity. Carbohydrate-active enzymes and oxidoreductases appear to play particularly important roles in SDM and SDZ degradation. Electron paramagnetic resonance (EPR) spectroscopy revealed the generation and evolution of OH and R during the biodegradation of SDM and SDZ, suggesting that beyond enzymatic degradation, SDM and SDZ were also transformed through a free radical pathway. Luffa fiber also acts as a co-substrate to improve the activity of enzymes for the degradation of SDM and SDZ. This research provides a potential strategy for removing SDM and SDZ from agricultural and industrial wastewater using fungal-luffa fiber systems.

Luffa fibers as promising reinforcement for polymer composites: Mechanical characterization of NaOH treated and untreated dumbbell test-pieces with Weibull statistics

Different materials require specific test-piece dimensions and designations for their mechanical characterization, present either in ASTM, ISO, or DIN norms. Natural polymers or bio-fibers are materials that have lignocellulosic fibrils that can be mechanically characterized as single fibers, which tend to be bundles of thinner hollow fibrils. In this work, a new approach has been applied to the unique natural fiber Luffa cylindrica, also called loofah or scourer, as loofah dumbbell test-pieces (LDTs) similar in length to the Type IV ASTM D-638 samples for unreinforced or reinforced plastics. 60 LDTs of 120 mm and 40 mm in length and width respectively were cut by hand, with and without alkali treatment (aqueous 2%NaOH), in transversal and longitudinal directions, to be characterized using testing speeds of 1 mm/min and 50 mm/min, SEM, XRD, statistics, and Weibull analysis. The resultant force vs. elongation/stress vs. strain graphs revealed a high variability of LDTs, and mercerization was found to increase their mechanical resistance. SEM images confirmed a microtubular cellular structure, XRD exposed an increment in crystallinity after alkali treatment, and Weibull indicated the probability of failure in 10 samples per configuration.

The prospective utilization of Luffa fibres as a lignocellulosic bio-material for environmental remediation of aqueous media: A review

Luffa is an excellent biomaterial that has gained much attention since it is low-cost, available, environmentally-friendly, non-toxic, porous and efficient for the removal of environmental pollutants, including dyes, pharmaceuticals, and heavy metals. This review provides an insight into the key factors, including contact time, pH, pollutant concentration, adsorbent dosage, and temperature that may affect the Luffa performance in removing contaminants. Thereafter, Luffa and its composites were characterized by SEM, FTIR, BET, XRD, EDAX, and TGA. This paper reviews the current state of research on the use of raw Luffa and modified Luffa, and compare the results with other investigations. It was found that Luffa – based composites might be great potential candidates for water decontamination. Adsorption equilibrium and kinetics were also studied and it was found that Langmuir/Freundlich and Pseudo-second order models were in great agreement for many studies. Results confirmed that Luffa and its composites possess good applicability in removing different types of pollutants from aqueous solutions.

A review on Luffa fibres and their polymer composites

Luffa spp. is readily available and widely grown in Asia and Africa and is a rich source of natural fibres for composite development. This paper reviews research findings on Luffa fibres and their composites. The progress of research, novel findings that affect the paradigm of the research area, recent trends, knowledge gaps and future perspectives are evaluated. It was found that the average chemical composition of Luffa fibres ranges from 57–74% cellulose, 14–30% of hemicellulose, 1–22% of lignin and 0–12.8% of the other components. Luffa fibres were usually extracted by drying. Furthermore, the most common modification technique was found to be by alkali mercerisation. About 53% of the research studies made use of epoxy resins for their base polymer making it the most popular polymer type for Luffa fibre reinforced composites. The composites are fabricated usually by manual mixing and hand layup and the most common curing technique was found to be compression moulding (about 63% of the research studies). The mechanical, thermal, crystalline and other properties of the composites are also considered in this review. Further interesting areas suggested for future work include investigation of the effect of drying, more trials with L. acutangula and utilisation of multi-resin ternary systems. It is concluded that Luffa is a promising material for composite development and based on its favourable properties is likely to continue playing an important role for the years to come.

Recent Developments in Luffa Natural Fiber Composites: Review

Natural fiber composites (NFCs) are an evolving area in polymer sciences. Fibers extracted from natural sources hold a wide set of advantages such as negligible cost, significant mechanical characteristics, low density, high strength-to-weight ratio, environmental friendliness, recyclability, etc. Luffa cylindrica, also termed luffa gourd or luffa sponge, is a natural fiber that has a solid potential to replace synthetic fibers in composite materials in diverse applications like vibration isolation, sound absorption, packaging, etc. Recently, many researches have involved luffa fibers as a reinforcement in the development of NFC, aiming to investigate their performance in selected matrices as well as the behavior of the end NFC. This paper presents a review on recent developments in luffa natural fiber composites. Physical, morphological, mechanical, thermal, electrical, and acoustic properties of luffa NFCs are investigated, categorized, and compared, taking into consideration selected matrices as well as the size, volume fraction, and treatments of fibers. Although luffa natural fiber composites have revealed promising properties, the addition of these natural fibers increases water absorption. Moreover, chemical treatments with different agents such as sodium hydroxide (NaOH) and benzoyl can remarkably enhance the surface area of luffa fibers, remove undesirable impurities, and reduce water uptake, thereby improving their overall characteristics. Hybridization of luffa NFC with other natural or synthetic fibers, e.g., glass, carbon, ceramic, flax, jute, etc., can enhance the properties of the end composite material. However, luffa fibers have exhibited a profuse compatibility with epoxy matrix.

Improvement of the Mechanical Properties of Plant Fiber-reinforced Composites through Hybridization

ABSTRACT The most important reason why natural fibers are not sufficiently involved in applications is the large scattering of their properties. In addition, it is very difficult to find one kind of natural fiber which has perfect mechanical properties like synthetic fibers. Here, we aimed to find solutions by developing a hybrid composite according to the expectations in the field of application. With this method, desired mechanical properties can be designed, and the weak properties can be improved. To be able to examine this method, we used two different fibers which have different mechanical characteristics. The mechanical properties were measured with three-point bending and impact resistance tests. According to the results, the flexural strength of the jute-reinforced composites (JC) has been improved by 44–71% using luffa fiber hybridization method. On the other hand, it has been observed that the impact resistance of the same specimens of JC has been improved by 51–83%. These results revealed that it is possible to improve the mechanical properties of the composites with hybridization. In conclusion, our study shows that bio-composites can be designed according to the requirement of the application. Hence, the application areas of bio-composites can be widened with increased usage rates.

Characterization of poly-hydroxybutyrate/luffa fibers composite material

Luffa fibers were evaluated as a reinforcement material in poly-hydroxy-butyrate matrix composites. The treatments consisted of varying the incorporation percentage of mercerized and non-mercerized luffa fibers in a poly-hydroxybutyrate (PHB) matrix (5%, 10%, and 20% w/v). Composites made with PHB and reinforced with luffa fibers (treated and non-treated) were mechanically evaluated (tensile strength, Young’s modulus, and percentage of elongation at break), the surface morphology was described by using scanning electronic microscopy, and the degradability behavior of composites was obtained. According to the results, mechanical properties decreased when the percentage of fibers increased and no significant effects were observed when compared with mercerized fiber composites. Degradability tests demonstrated that the weight loss increased with increased fiber content in composites, independent of the applied pretreatments. Microscopy images exhibited that mercerization improved the fiber incorporation into the polymeric matrix, diminishing the “pull out” effect; the above-mentioned result was supported by using the Fourier-transform infrared spectroscopy technique, observing the reduction of lignin and hemicellulose peaks in mercerized fibers. Based on the composite mechanical performance and degradability behavior, it was concluded that this material could be used in the packaging sector as biodegradable secondary packaging material.

Study of Thermal Behaviour of Poly(Lactic) Acid Composites with Gamma Irradiated Luffa Fiber

Modification of surface of natural fibers by high-energy gamma irradiation (6 MV) is a competent process for enhancing the adhesion between fiber and matrix. Composites reinforced with natural fiber have gained a prominent place in the field of research and innovation due to the advantages such as low cost, lightweight and environment friendly. We have studied the thermal properties of biodegradable composites using biodegradable polymer poly(lactic) acid and fiber of Luffa cylindrica (LC) fabricated by using injection molding technique. Before reinforcement LC fibers are irradiated with gamma rays of 0.5, 1 and 2 Gy using 6 MV linear accelerator at room temperature in the presence of air. The thermal properties like glass transition temperature (Tg), crystallization temperature (Tcc), melting peak temperature (Tm) and thermal stability of the composites are studied using differential scanning calorimetry in the temperature range from 30 to 250 °C and thermogravimetric analysis in temperature range from 20 to 700 °C. The variation of these properties in response to the irradiation dose and fiber loading is analyzed in detail. It is observed that with increase in irradiation dose, glass transition temperature and crystallization temperature are increasing. However, the thermal stability of the composites is found to decrease with increase in irradiation dose.

Effect of degree of silanization of luffa on the properties of luffa-epoxy composites

Luffa fibers were silane functionalized using varied concentrations of 3-aminopropyl trimethoxysilane (APTMS) in methanol solution to investigate the relationship between the concentration of silanizing agent and the effective degree of silanization of luffa fibers. The aim of the present work was to identify the optimal silane concentration to adequately functionalize the luffa fibers and to investigate its influence on the properties of luffa-epoxy composites. The degree of silanization was controlled by varying the weight ratios of fiber and APTMS (1:0.5, 1:1, 1:1.5, and 1:2). The optimal degree of silanization was confirmed by testing the mechanical, thermal, and flammable properties of functionalized luffa fiber-filled epoxy matrix composites. The composite with 1:1.5 w/w silane functionalization exhibited a maximum tensile strength of 18.4 ± 0.94 MPa. The interfacial adhesion of the prepared samples is investigated through morphological studies. Thermal studies indicated that thermal stability increased with an increase in silanization. TGA analysis revealed that the silane treatment improved the thermal profile of the composites with initial degradation above 240 °C. The storage modulus of composites decreased with an increase in temperature with a 3-stage pattern of the slope. The storage modulus and Tg increased with an increase in silanization degree and the loss modulus peak shifted towards higher temperature with the increase in silanization. Flame retardant studies show that the optimized composite exhibits V-1 rating suggesting the suitability of the prepared composite for various applications.

Effect of Chemical Treatment on the Mechanical Properties of Luffa Fiber Reinforced Epoxy Composite

Novel luffa fiber reinforced epoxy composites are prepared and their mechanical properties are investigated before and after chemical treatment. The unique natural knitting structure of luffa provides an excellent reinforcement to the epoxy matrix. Knowing that the fiber-matrix bond gets stronger and imparts more strength to the composite when chemical treatment is done on fibers, composites are manufactured by untreated and treated luffa fiber using epoxy as a matrix. Luffa fiber is treated using benzoyl chloride and NaOH. Tensile and flexural tests are conducted on composites to investigate the effect of chemical treatment. Test results have shown that the chemical treatment on fibers improved the tensile strength, tensile modulus, flexural strength and flexural modulus by 27.21%, 49.37%, 41.84% and 6.44% respectively. Tensile modulus of luffa fiber composite is found to be higher compared with commonly used natural fiber composites. The experimental investigation suggests that, chemically treated luffa fiber reinforced epoxy composites could be a potential lightweight material in various applications.