Isolation and Characterization of Cellulose Nanofiber(CNF)from Kenaf(Hibiscus cannabinus)Bast through the Chemo-Mechanical Process

The present work emphasizes the isolation of cellulose nanofiber(CNF)from the kenaf(Hibiscus cannabinus)bast through a chemo-mechanical process.In order to develop high CNF yield with superior properties of CNF for improving compatibility in varied applications this method is proposed.The fiber purification involved pulping and bleaching treatments,whereas mechanical treatment was performed by grinding and high-pressure treatments.The kraft pulping as a delignification method followed by bleaching has successfully removed almost 99%lignin in the fiber with high pulp yield and delignification selectivity.The morphology of the fibers was characterized by scanning electron microscopy,which showed a smooth surface,fiber bundles,gel-shaped nanofiber,and an average size of 94.05 nm with 69%of CNF in 34–100 nm size.The chemo-mechanical process exhibited a more crystalline nature in CNF than pulp kenaf.The low zeta potential values exhibit the distribution of fibrils and colloidal suspension stability without any further agglomeration.A lower concentration of CNF is less stable exhibiting the product agglomeration.Therefore,the chemo-mechanical process for the isolation of CNF(Hibiscus cannabinus)from kenaf involves sustainable,low-cost,non-toxic,and cheap alternatives than other traditional methods.

Development of Ecological Absorbent Core Sanitary Pads in Combination of Kenaf and Chitosan Fibers

The menstrual cycle is always considered as a big nightmare by many women. This research aims to make this process smooth and safe by developing natural sanitary pads which are used to absorb and retain menstrual blood from the body. Some existing sanitary pads contain 90% plastics made of non-woven polypropylene/polyethylene sheets, super absorbent polymers, and polyethylene back sheets that will take up to 600 - 800 years to decompose. So, biodegradable sanitary pads using natural fibers are the best alternative to eliminate the pads which contain non-biodegradable materials. In this research, nonwoven bamboo will be used as the top layer, nonwoven cotton will be used as the second layer, the absorbent core is to be made by the combination of kenaf and chitosan fibers as the third layer, cotton as the fourth layer, and cornstarch-based bioplastic sheets as the bottom layer. These biodegradable natural materials will change the menstrual process into a healthy one as well as create a robust ecological community.

Study on Vigor of Kenaf Seeds Stored with Different Packaging Methods for 31 Years

This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.

Assessment of Pb uptake,translocation and immobilization in kenaf (Hibiscus cannabinus L.) for phytoremediation of sand tailings

The potential of kenaf (Hibiscus cannabinus L.) for phytoremediation of lead (Pb) on sand tailings was investigated.A pot experiment employing factorial design with two main effects of fertilizer and lead was conducted in a nursery using sand tailings from an ex-tin mine as the growing medium.Results showed that Pb was found in the root,stem,and seed capsule of kenaf but not in the leaf.Application of organic fertilizer promoted greater biomass yield as well as higher accumulation capacity of Pb.In Pb-spike...

Effect of Cadmium Stress on the Growth, Antioxidative Enzymes and Lipid Peroxidation in Two Kenaf (Hibiscus cannabinus L.) Plant Seedlings

The effects of cadmium stress on the growth, antioxidative enzymes and lipid peroxidation in two kenaf plants, Fuhong 991 and ZM412, were analysed under control （0.5-strength Hoagland＇s nutrient solution） or five levels of cadmium stress （0.5- strength Hoagland＇s nutrient solution containing different concentrations of Cd2＋）. The leaves and roots of control and cadmium-stressed plants were harvested after 3 wk. At the same Cd concentration, the Cd tolerance index of Fuhong 991 was higher than that of ZM412, indicating that Fuhong 991 may be more tolerant to Cd than ZM412. The superoxide dismutase （SOD）, catalase activity （CAT） and peroxidase （POD） activities fluctuated in the leaves of the Cd-stressed plants compared to the control, whereas the glutathione reductase activity （GR） was much larger than the control for Fuhong 991, ensuring that sufficient quantities of GSH were available to respond to the cadmium stress. In comparison to the control, the dynamic tendency of the SOD, CAT and POD activities in roots of the Cd-stressed plants all increased and then declined, but the POD activity of Fuhong 991 remained nearly unchanged at all of the stress levels. The increase in the enzyme activities demonstrated that Fuhong 991 was more tolerant to cadmium than ZM 412. The lipid peroxidation was enhanced only in the leaves of Cd-stressed ZM 412. These findings indicated that antioxidative activities may play important roles in Cd-stressed Fuhong 991 and ZM 412 and that the leaf and root cell membranes of Fuhong 991 have a greater stability than those of ZM 412. For pollution monitoring purposes, the GR activity in the roots and leaves may serve as a biomarker of Cd for Fuhong 991, whereas lipid peroxidation may serve as biomarker for ZM 412.

Optimization of Two-Dimensional Gel Electrophoresis for Kenaf Leaf Proteins

To establish a suitable and effective protocol of protein extraction for two-dimensional gel electrophoresis （2-DE） analysis in kenaf leaf tissues, three extraction methods （trichloroacetic acid/acetone, urea/thiourea, and phenol extraction methods） were applied to the extraction of kenaf leaf protein. The results were compared in regard to protein extraction efficiency, sodiumdodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）, and 2-DE gels. Furthermore, the 2-DE system was optimized for four aspects： the pH range of IPG （immobilized pH gradient） stripes, sampling methods, sample volumes, and concentration of polyacrylamide gels. The data presented showed that the phenol extraction method is the best method to perform 2-DE analysis of kenaf leaf protein. The protein extracted from phenol extraction method reached the purity of （26.40±0.859）%, showed （25.67±1.53） protein bands in one dimension SDS-PAGE gels, and （1 374±54.44） protein spots on 2-DE gels. The research also indicates that kenaf leaf protein spots were distributed mainly within the pH range of 4-8. More clear background with a better distribution effect and many protein spots could be obtained on 2-DE gels under the conditions of active rehydration loading, 24 cm IPG strips （linear pH gradient of 4-7）, 1.4 mg samples, and 12% SDS-PAGE gels.

A Genetic Linkage Map of Kenaf (Hibiscus cannabinus L.) Based on SRAP, ISSR and RAPD Markers

Kenaf （Hibiscus cannabinus L.） is one of the most economically important crops for non-wood fiber production. The objective of this study was to establish a genetic linkage map of kenaf with higher density of molecular markers. A semi- wild variety Ga42 and a cultivar Alain kenaf were used as parents to construct an F2 population consisting of 155 plants. The genetic linkage map comprising 134 marker loci was constructed, including 65 sequence-related amplified polymorphism （SRAP）, 56 inter-simple sequence repeat （ISSR）, and 13 randomly amplified polymorphic DNA （RAPD） markers. This map spans 2 108.9 cM and contains 20 linkage groups with an average marker density of 15.7 cM between the adjacent markers.

Effect of Fiber Loadings and Treatment on Dynamic Mechanical, Thermal and Flammability Properties of Pineapple Leaf Fiber and Kenaf Phenolic Composites

This study deals with the analysis of dynamic mechanical,thermal and flammability properties of treated and untreated pineapple leaf fiber(PALF)and kenaf fiber(KF)phenolic composites.Results indicated that storage modulus was decreased for all composites with increases in temperature and pattern of slopes for all composites,having almost the same values of E′at glass transition temperature(Tg).The peak of the loss modulus of pure phenolic composites was shown to be much less.After the addition of kenaf/PALF,peaks were higher and shifted towards a high temperature.The Tan delta peak height was low for pure phenolic composites and maximum for 60%PALF phenolic composites.Cole-Cole analysis was carried out to understand the phase behavior of the composite samples.Thermogravimetric analysis(TGA)results indicated that pure phenolic composites have better thermal stability than PALF and kenaf phenolic composites.Vertical and horizontal UL-94 tests were conducted and showed pure phenolic resin is highly fire resistant.The overall results showed that treated KF composites enhanced the dynamic mechanical and thermal properties among all PALF/KF composites.

Physical and damping properties of kenaf fibre filled natural rubber/thermoplastic polyurethane composites

The paper presents the investigation of the effect of alkaline treatment of sodium hydroxide(NaOH) on physical and dynamic mechanical analysis(DMA) viscoelastic properties of kenaf fibre filled natural rubber(NR)/thermoplastic polyurethane(TPU) composites.The treated kenaf fiber,NR and TPU were weighed and proportioned according to the required compositions and were blended using hot mixed Brabender machine.The polymer composites were then fabricated using the hot press to form a sample board.The sample was cut and prepared and water absorption,density,thickness swelling and DMA tests were performed.As far as physical properties are concerned,composites with the highest NR amount of shows the best results,which indicates good fiber bonding adhesion.The polymer composites with the highest amount of TPU shows the highest damping properties at high temperature.

Preliminary Study on Tensile and Impact Properties of Kenaf/Bamboo Fiber Reinforced Epoxy Composites

The application of natural fibers as reinforcement in composite material has increased due to environmental concerns,low cost,degradability and health concerns.The purpose of this study is to identify the best type of bamboo fibers to be used as reinforcement for kenaf(K)/bamboo hybrid composite.There were three types of bamboo fibers evaluated in this study which include bamboo mat(B),bamboo fabric(BF)and bamboo powder(BP).Chemical composition of B,BF,BP and K fibers were analyzed in this study.The effect of different types of bamboo fibers on tensile,impact,and morphological properties were investigated.The B/epoxy composites displayed the highest tensile strength(53.03 MPa)while K/epoxy composite had the highest tensile modulus(4.71 GPa).Scanning electron micrographs of B/epoxy composites displayed better fiber/matrix interfacial bonding in comparison to other studied composites.Results showed that impact strength of BF-based composite was highest(45.70 J/m).In conclusion,the tensile strength of B/epoxy composite is superior to the other bamboo reinforced composites and will be further evaluated in the next study.

Effect of Hybridization on the Mechanical Properties of Pineapple Leaf Fiber/Kenaf Phenolic Hybrid Composites

In this study,pineapple leaf fiber(PALF),kenaf fiber(KF)and PALF/KF/phenolic(PF)composites were fabricated and their mechanical properties were investigated.The mechanical properties(tensile,flexural and impact)of the PALF/KF/PF hybrid composites were investigated and compared with PALF/KF composites.The 3P7K exhibited enhanced tensile strength(46.96 MPa)and modulus(6.84 GPa),flexural strength(84.21 MPa)and modulus(5.81 GPa),and impact strength(5.39 kJ/m2)when compared with the PALF/PF and KF/PF composites.Scanning electron microscopy(SEM)was used to observe the fracture surfaces of the tensile testing samples.The microstructure of the 7P3K hybrid composite showed good interfacial bonding and the addition of KF improved the interfacial strength.It has been concluded that the 3P7K ratio allowed obtaining materials with better mechanical properties(tensile,flexural and impact strengths)than PALF/PF and KF/PF composites.The results obtained in this study will be used for further comparative study of untreated hybrid composites with treated hybrid composites.

Vertex angles effects in the energy absorption of axially crushed kenaf fibre-epoxy reinforced elliptical composite cones

Experimental quasi-static crushing tests were conducted by using a universal testing machine format kenaf-epoxy composite elliptical cones. The work focused on the vertex angle's effects on energy absorption capability; the vertex angles vary from 0° to 24° in 6 increments. The failure modes of the kenaf fibre epoxy composite elliptical cones were observed utilising delegate photos taken during the quasistatic crushing test. Load-deformation curves and deformation histories of typical specimens are presented and discussed. Moreover, the effects of cone vertex angles on the load carrying capacity and the energy absorption capability are also discussed. The results show that the energy absorption abilities significantly influence the ellipticity vertex angle as the load carrying capacity. We concluded that the quasi-static axial crushing behaviour of elliptical mat laminated composite cones is strongly affected by their structural geometry and the specific energy absorbed by the composite elliptical cones with vertex angles of 6°, 12°, 18°, and 24°, which is more than an elliptical cone with the vertex angle of 0°(the elliptical tube) at any given deformation. However, the specific energy absorption for the elliptical composite cone showed a positive correlation, i.e., the more the angle increased, the more energy was absorbed. In this regard, an elliptical composite cone with a 24° angle exhibited the best energy absorption capability.

Phenolics-saponins rich fraction of defatted kenaf seed meal exhibits cytotoxicity towards cancer cell lines

Objectives: To determine the cytotoxicity of crude ethanolic extract, n-butanol fraction and aqueous fraction on selected cancer cell lines, and to observe the morphological changes of the cancer cells treated with n-butanol fraction.Methods: The cytotoxic effect of n-butanol fraction, crude ethanolic extract and aqueous fraction on breast cancer(MCF-7 and MDA-MB-231), colon cancer(HT29), lung cancer(A549), cervical cancer(He La) and normal mouse fibroblast(3T3) cell lines was determined using MTT assay. The morphological changes of the treated cells were observed under an inverted light microscope.Results: n-Butanol fraction was the most cytotoxic towards HT29 and MCF-7 cells in a dose-dependent manner compared to crude ethanolic extract and aqueous fraction(P < 0.05). The IC50 of n-butanol fraction for HT29 and MCF-7 was(780.00 ± 28.28)and(895.00 ± 7.07) mg/m L, respectively. Cell shrinkage, membrane blebbing and formation of apoptotic bodies were noted following treatment of HT29 cells with n-butanol fraction.Conclusions: In conclusion, n-butanol fraction was more cytotoxic than crude ethanolic extract and aqueous fraction towards the selected cancerous cell lines and induced apoptosis in HT29 cells.

Mechanism of Kenaf Retting Using Aerobes

The experimental results showed that the duration of microbial retting processing of kenaf fibers by using aerobic microbe was four times shorter than that by using anaerobic microbe. The residual gum percentage,breaking strength, breaking elongation and linear density of aerobic retted kenaf bundle fibers did not show significantly difference with that of anaerobic retted kenaf bundle fibers by ANOVA-Tukey's studentized test at a = 5% except for the softness. The bioenergetic principle and the calculation of the amount of ATP produced during the decomposition processing of kenaf gums were used to explain why the retting duration in the case of using aerobic microbes was much shorter than that of using anaerobic microbes.

Protein extract of kenaf seed exhibits anticoagulant,antiplatelet and antioxidant activities

Objective:To explore the anticoagulant,antiplatelet and antioxidant activities of protein extract of kenaf seed(PEKS).Methods:Sodium dodecyl sulphate polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography techniques were employed for protein characterization.Antioxidant activity of PEKS was assessed using 1,1-diphenyl-2-picrylhydrazyl(DPPH)assay.The protective effect of PEKS on sodium nitrite(NaNO2)induced oxidative stress was evaluated using the in vitro red blood cell model,while the effect of PEKS on diclofenacinduced oxidative stress was examined in vivo in rats.Platelet-rich plasma and platelet-poor plasma were used for anticoagulant and antiplatelet activities of PEKS.Results:PEKS revealed similar protein bands on SDS-PAGE under reduced and non-reduced conditions.Several acidic proteins were present in native PAGE.PEKS showed antioxidant properties by scavenging DPPH with an IC50 of 24.58μg.PEKS exhibited a protective effect on NaNO2 induced oxidative stress in red blood cells by restoring the activity of stress markers.In addition,PEKS alleviated diclofenac-induced tissue damage of the liver,kidney,and small intestine.PEKS showed an anticoagulant effect in both in vivo and in vitro experiments by enhancing normal clotting time.PEKS did not affect prothrombin time but increase activated partial thromboplastin time.Furthermore,PEKS inhibited adenosine diphosphate and epinephrine-induced platelet aggregation.Conclusions:PEKS protects tissues from oxidative stress and exhibits antithrombotic activity.

Preparation of Kenaf Biochar and Its Adsorption Properties for Methylene Blue

The toxic dyestuff's from printing and dyeing wastewater have caused serious damages to the ecological environ-ment,thus exploring effective methods to remove them having become a key topic.Here,a series of biochar sam-ples were synthesized form kenaf to adsorb methylene blue(MB),which was acted as the dye representative for the test of adsorption capacity due to the presence of abundant double bond and aroma tic heterocyclic ring.By tuning the raw materials and pyrolysis temperature,a super adsorption capacity about 164.21 mg·g^(-1) was obtained over the biochar that pyrolyzed at 700℃ with the kenaf fiber as raw material Through the physical adsorption,elemental analysis,FTIR spectra and NH_(3)-TPD,it was found the high surface area and pore volume of biochar played a key role in the adsorption of MB,and the acidic sites would also assist the adsorption process.Besides,the adsorption kinetic model was ftted and calculated,implying the MB physically adsorbed on the bio-char rapidly and then occurred chemical adsorption on the acidic sites.In addition,through KBC700 recycling experiments,it was found that kenaf biochar had a good binding force to MB,which effectively avoided secondary pollution.This work provides important insights for the adsorption mechanism of MB by biochar,also offers some guidance for the further synthesis of biochar from various biomass.

The Role of Bamboo Nanoparticles in Kenaf Fiber Reinforced Unsaturated Polyester Composites

In this study,bamboo nanoparticles in concentration ranges from 0-5%were incorporated along with woven/nonwoven kenaf fiber mat into unsaturated polyester and the developed composites were further characterized.Bamboo chips were subjected to ball milling process for the synthesis of nanoparticles with a particle size of 52.92 nm.The effect that the incorporation of nanoparticles had on various properties of reinforced composites was further observed.Due to the high surface area of nanoparticles,incorporation of 3%of nanofillers contributed towards strong bonding and better wettability with matrix,thus resulting in excellent mechanical properties and thermal characteristics in reinforced unsaturated polyester composites.Furthermore,mechanical characteristics of reinforced composites were deteriorated by the addition of a higher percentage of nanoparticles(>3%)due to agglomeration,as confirmed by scanning electron microscopy.Moreover,ordered structural arrangement of woven kenaf textile fiber showed enhancement in interfacial adhesion and promoted superior mechanical strength in reinforced composites as compared with nonwoven composites.

Identification of DNA Photolyase Gene of a Drought Tolerance Branching Line of Kenaf (<i>Hibiscus cannabinus</i>L.)

DNA photolyase is a photoreactivation enzyme which has a role in the mechanism of DNA repair. The existence of DNA photolyase gene could affect the success of mutation process. SM026H is a drought tolerance branching line of kenaf identified by Research Institute for Tobacco and Fibre Crops, Karangploso, Malang, Indonesia which has a potential as a source for mutation breeding. In this research, cloning and sequencing of the DNA photolyase gene of line SM026H were conducted. The DNA of SM026H leaves was isolated using DNeasy Kit, then was amplified by Polymerase Chain Reaction (PCR) using AC1 as a forward primer, paired with AC3R or AC4R as reverse primers and checked using electrophoresis on a 0.7% agarose gel. The AC1-AC3R primer pair produced a DNA fragment with a size of 750 bp, whereas the AC1-AC4R primer pair produced a DNA fragment of 1000 bp in size. Cloning of the AC1-AC3R and AC1-AC4R fragments was done prior to sequencing. Preparation for cloning was done by running and extracting the PCR products from a 0.7% Low Melting Agarose (LMA), and then ligating them to a pCR21 plasmid using an electroporation method. Two sub-fragments of each AC1-AC3R and AC1-AC4R fragments were identified. They were 600 bp and 500 bp, resulting from the AC1-AC3R fragment, and 1300 bp and 500 bp, resulting from the AC1-AC4R fragment. The sequencing result of those sub-fragments was analyzed using a Basic Local Alignment Search Tool (BLAST) program. It was shown that the sequences have a degree of homology to DNA photolyase sequence of Arabidopsis thaliana A. thaliana, Cucumis sativus, Spinacia oleracea, Stellaria longipes and Oryza sativa. These suggested that the kenaf line SM0026H possesses the DNA photolyase gene. However, further study needs to be done to ascertain that the gene was not the cryptochrome.

Fiber Loading of Date Palm and Kenaf Reinforced Epoxy Composites:Tensile,Impact and Morphological Properties

Date palm fiber(DPF)and kenaf fiber were reinforced in epoxy having various fiber loading 40%,50%,and 60%by weight.These hybrid samples were manufactured by hot press technique and then characterized for tensile,impact,and morphological behavior to evaluate the ratio of fibers in the hybrid composites;the addition of kenaf improved the tensile properties,Scanning Electron Microscopy(SEM)revealed the interfacial bonding of fiber/matrix,and dispersion and void content in composites.Impact test studies reflected the effect of natural fiber with epoxy,level of stress transfer from matrix to reinforced material,and reinforced material’s role in absorbing the impacts.It showed that 50%of DPF had the best shock-absorbing capacity.The obtained results indicated that 30%DPF in hybrid composite showed improved tensile properties and homogeneous distribution of fiber without void content;however,50%DPF loading in hybrid composites had the best impact properties.

Optimisation of Crude Oil Adsorbent Developed from a Modified Styrene Kenaf Shive

A new kind of hydrophobic crude oil sorbent was successfully developed by grafting kenaf shive with styrene monomer. In this paper, crude oil sorbents were developed through regeneration method by varying the initiator concentration, monomer ratio and particle sizes in the range of 0.5 - 2.5 wt%, 0.5 - 2.0 wt % and 125 - 1000 μm respectively. This research approach for the development of crude oil sorbent from graft modified kenaf shive/core and the aforementioned variable optimization has not been reported. The effect studies of the individual and combine factors were carried out using a statistical experimental design matrix using five-level central composite design (CCD). Respond surface methodology (RSM) was used to optimise and develop equations of the aforementioned variables (initiator concentration, monomer ratio and particle sizes). The optimal swelling capacity of 616% and 267% lower retention were achieved at initiator concentration, monomer ratio and particle size of 12.5 wt%, 1.50 wt% and 562 μm respectively. TGA-DTA, XRD and BET analysis were carried out on optimised sample and, FTIR was carried on both unmodified (UG) and optimized sorbent. Further computations were done for grafting efficiency (GE), homopolymers and density. The findings display the effect of the three variables and navigation equations were generated for further investigations on them. However, the results show the feasibility and robustness of facile oil sorption.