Showing papers on "SISAL published in 2002"
TL;DR: In this article, the thermal properties, crystallinity index, reactivity, and surface morphology of untreated and chemically modified fibers have been studied using differential scanning calorimetry (DSC), X-ray diffraction (WAXRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), respectively.
Abstract: Plant fibers are rich in cellulose and they are a cheap, easily renewable source of fibers with the potential for polymer reinforcement. The presence of surface impurities and the large amount of hydroxyl groups make plant fibers less attractive for reinforcement of polymeric materials. Hemp, sisal, jute, and kapok fibers were subjected to alkalization by using sodium hydroxide. The thermal characteristics, crystallinity index, reactivity, and surface morphology of untreated and chemically modified fibers have been studied using differential scanning calorimetry (DSC), X-ray diffraction (WAXRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), respectively. Following alkalization the DSC showed a rapid degradation of the cellulose between 0.8 and 8% NaOH, beyond which degradation was found to be marginal. There was a marginal drop in the crystallinity index of hemp fiber while sisal, jute, and kapok fibers showed a slight increase in crystallinity at caustic soda concentration of 0.8–30%. FTIR showed that kapok fiber was found to be the most reactive followed by jute, sisal, and then hemp fiber. SEM showed a relatively smooth surface for all the untreated fibers; however, after alkalization, all the fibers showed uneven surfaces. These results show that alkalization modifies plant fibers promoting the development of fiber–resin adhesion, which then will result in increased interfacial energy and, hence, improvement in the mechanical and thermal stability of the composites. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2222–2234, 2002
1,396 citations
TL;DR: In this paper, the influence of water uptake on the tensile properties of short sisal/PP composites has been studied with special reference to the effect of ageing conditions like treatment with water and UV radiation.
446 citations
TL;DR: In this paper, longitudinal stiffeners were used in composite materials for use in composite composite materials, where plant fibers are of increasing interest for composite materials and waste management is easier than with glass fibers.
Abstract: Plant fibers are of increasing interest for use in composite materials. They are renewable resources and waste management is easier than with glass fibers. In the present study, longitudinal stiffn ...
219 citations
TL;DR: In this paper, the effectiveness of various surface modification of sisal fibers involving dewaxing, alkali treatment, bleaching cyanoethylation and viny1 grafting in enhancing the mechanical properties, such as tensile, flexural and impact strength, of Sisal-polyester biocomposites was discussed.
Abstract: This article concerns the effectiveness of various types and degrees of surface modification of sisal fibers involving dewaxing, alkali treatment, bleaching cyanoethylation and viny1 grafting in enhancing the mechanical properties, such as tensile, flexural and impact strength, of sisal-polyester biocomposites. The mechanical properties are optimum at a fiber loading of 30 wt%. Among all modifications, cyanoethylation and alkali treatment result in improved properties of the biocomposites. Cyanoethylated sisal-polyester composite exhibited maximum tensile strength (84.29 MPa). The alkali treated sisal-polyester composite exhibited best flexural (153.94 MPa) and impac strength (197.88 J/m), which are, respectively, 21.8% and 20.9% higher than the corresponding mechanical properties of the untreated sisal-polyester composites. In the case of vinyl grafting, acrylonitrile (AN)-grafted sisal-polyester composites show better mechanical properties than methyl-methacrylate (MMA)-grafted sisal composites. Scanning electron microscopic studies were carried out to analyze the fiber-matrix interaction in various surface-modified sisal-polyester composites.
115 citations
TL;DR: In this article, the femur grafting of sisal fibers by maleic anhydride modified polypropylene (MAPP), benzyl chloride and permanganate has been shown to improve the tensile strength of the resulting composite.
Abstract: Sisal fibers have been used for the reinforcement of polypropylene matrix. The compatibilization between the hydrophilic cellulose fiber and hydrophobic PP has been achieved through treatment of cellulose fibers with sodium hydroxide, isocyanates, maleic anhydride modified polypropylene (MAPP), benzyl chloride and by using permanganate. Various fiber treatments enhanced the tensile properties of the composites considerably, but to varying degrees. The SEM photomicrographs of fracture surfaces of the treated composites clearly indicated the extent of fiber–matrix interface adhesion, fiber pullout and fiber surface topography. Surface fibrillation is found to occur during alkali treatment which improves interfacial adhesion between the fiber and PP matrix. The grafting of the fibers by MAPP enhances the tensile strength of the resulting composite. It has been found that the urethane derivative of polypropylene glycol and cardanol treatments reduced the hydrophilic nature of sisal fiber and thereby enhanced ...
110 citations
TL;DR: In order to improve the above qualities, various surface treatments of sisal fiber like mercerization, cyanoethylation, acetylation, bleaching and vinyl monomer (acrylonitrile) grafting are carried out which results in improved mechanical performance of Sisal-BAK composites as discussed by the authors.
Abstract: Lignocellulosic natural fibers like sisal and pineapple leaf fiber (PALF) can be incorporated in polymers based on biodegradable polyester amide matrix, BAK 1095 for achieving desired properties and texture in the resulting biocomposites. But high level of moisture absorption, poor wettability and insufficient adhesion between untreated fiber and the polymer matrix led to debonding with age. In order to improve the above qualities, various surface treatments of sisal fiber like mercerization, cyanoethylation, acetylation, bleaching and vinyl monomer (acrylonitrile) grafting are carried out which results in improved mechanical performance of sisal-BAK composites. Mechanical properties like tensile and flexural strength are optimum at a fiber loading of 50 wt%. Among all modifications, alkali treatment and acetylation result in improved properties of the composites. Alkali treated sisal composite shows about 20% increase in tensile strength and acetylated sisal composite shows about 14% increase in flexural...
95 citations
TL;DR: In this paper, short sisal fiber-reinforced polypropylene (PP) composites were prepared by melt blending followed by injection molding, and the PP matrix was maleated (MAPP) by blending PP and maleic-anhydride-grafted-PP in the weight ratio of 9/1.
Abstract: Short sisal fiber (SF)-reinforced polypropylene (PP) composites were prepared by melt blending followed by injection molding. To improve the interfacial bonding between SF and PP, the PP matrix was maleated (MAPP) by blending PP and maleic–anhydride-grafted-PP in the weight ratio of 9/1. It was found that the SF/MAPP composites have lower melt viscosity (as reflected by torque rheometer measurements) than the SF/PP composites at the respective sisal fiber contents. In terms of mechanical properties, PP maleation has the effect of improving the tensile strength. This can be explained in terms of the improved SF/matrix interfacial bonding when MAPP was used. However, the impact strength was reduced when the PP matrix was maleated. The improved SF/matrix interfacial bonding prevented fracture mechanisms such fiber/matrix debonding and fiber pullout from taking place. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 169–176, 2002
92 citations
TL;DR: In this article, the effects of plasma treatment on interfacial bonding between sisal fibres and polypropylene are evaluated by means of a single fibre pull-out test and the optimum treatment parameters have been found to be the shortest plasma treatment time, medium power level and medium chamber pressure.
Abstract: Argon- and air-plasma treatments have been used to modify the surface of sisal fibres. The Taguchi method of experimental design with three factors and three levels is used to optimise the treatment parameters in relation to fibre strength. The effects of plasma treatment on interfacial bonding between sisal fibres and polypropylene are evaluated by means of a single fibre pull-out test. The optimum treatment parameters have been found to be the shortest plasma treatment time, medium power level and medium chamber pressure. Under optimal treatment, the interfacial shear strength of air-plasma treated fibres is higher than that of the argon-plasma treated fibres. Scanning electron microscopy analyses show that the overall roughness of the plasma treated fibre surface increases with treatment time. The Ar-plasma treated fibre surface reveals obvious corrugations whereas cracking is apparent on the air-plasma treated fibre surface.
76 citations
TL;DR: In this article, a study of the mechanical, thermal and morphological behavior of blends of polypropylene filled with wood flour and sisal fiber (PP/wood flour, PP/sisal fibre), subjected to different doses of gamma irradiation (10, 25, 30, 50, 60 and 70 kGy), at room temperature and in the presence of oxygen.
63 citations
TL;DR: In this paper, the melt mixing characteristics, thermal properties, morphology, crystalline structure, and mechanical behavior of isotactic polypropylene (PP) and sisal fiber (SF) composites were systematically investigated.
Abstract: Composites based on isotactic polypropylene (PP) and sisal fiber (SF) were prepared by melt mixing and injection molding. The melt mixing characteristics, thermal properties, morphology, crystalline structure, and mechanical behavior of the PP/SF composites were systematically investigated. The results show that the PP/SF composites can be melt mixed and injection molded under similar conditions as the PP homo-polymer. For the composites with low sisal fiber content, the fibers act as sites for the nucleation of PP spherulites, and accelerate the crystallization rate and enhance the degree of crystallinity of PP. On the other hand, when the sisal fiber content is high, the fibers hinder the molecular chain motion of PP, and retard the crystallization. The inclusion of sisal fiber induces the formation of β-form PP crystals in the PP/SF composites and produces little change in the inter-planar spacing corresponding to the various diffraction peaks of PP. The apparent crystal size as indicated by the several diffraction peaks such as L (110)α , L (040)α , L (130)α and L (300)β of the α and β-form crystals tend to increase in the PP/SF composites considerably. These results lead to the increase in the melting temperature of PP. Moreover, the stiffness of the PP/SF composites is improved by the addition of sisal fibers, but their tensile strength decreases because of the poor interfacial bonding. The PP/SF composites are toughened by the sisal fibers due to the formation of β-form PP crystals and the pull-out of sisal fibers from the PP matrix, both factors retard crack growth.
43 citations
TL;DR: In this article, the thermoplasticity and mechanical properties of the chemically modified wood flour changed with the substitution reaction conditions, and the reinforcing sisal fibers were not well impregnated by the matrix because of the relatively high viscosity of the benzylated fir sawdust.
Abstract: Benzylation of sawdust from China fir was carried out to prepare plastics based on natural resources. It was found that thermoplasticity and mechanical properties of the chemically modified wood flour changed with the substitution reaction conditions. By compounding sisal fibers and the plasticized fir sawdust, unidirectional laminates were manufactured in a method similar to conventional thermoplastic composites. Such an all-plant fiber composite material is characterized by easy processing, environmental friendliness, and low cost. Instead of chemical heterogeneity of conventional composites, physical heterogeneity of the current natural fiber composite should be favorable for interfacial interaction. However, the reinforcing sisal fibers were not well impregnated by the matrix because of the relatively high viscosity of the benzylated fir sawdust. Further efforts should be made in this area on the basis of the current preliminary work in order to improve mechanical properties of the composites.
TL;DR: Chopped sisal fibers and finely powdered high-density polyethylene were surface functionalized using dichlorosilane (DS) under radio frequency (RF)-plasma conditions and characterized by electron spectroscopy for chemical analysis (ESCA) and fluorescence labeling techniques as discussed by the authors.
Abstract: Chopped sisal fibers and finely powdered high-density polyethylene were surface functionalized using dichlorosilane (DS) under radio frequency (RF)-plasma conditions and characterized by electron spectroscopy for chemical analysis (ESCA) and fluorescence labeling techniques. A high-capacity (10 L), rotating, 13.56 MHz, electrodeless plasma installation, specially designed to allow the uniform surface modification of powdery and particulate matter of irregular shape, was used. A three-factor fractional experimental design was employed to evaluate the effect of RF-power, pressure, and reaction time on the ESCA-based relative atomic composition of plasma-treated samples. It was demonstrated that SiHxCly functionalities are present on plasma-exposed surfaces and these functionalization reactions can be controlled by selecting proper plasma parameters. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2145–2154, 2002
TL;DR: In this article, the incorporation of oxygen polar groups in the polypropylene surface and the surface degradation and chain scission of both polyethylene and sisal fibers were investigated, and the mechanical properties of their composites were tested.
Abstract: Polypropylene powder and sisal fibers were oxygen plasma treated, and the mechanical properties of their composites were tested. Two main effects were investigated: the incorporation of oxygen polar groups in the polypropylene surface and the surface degradation and chain scission of both polypropylene and sisal fibers. Prior to these treatments, three reactor configurations were tested to investigate the best condition for both effects to occur in PP films. Results showed that polypropylene-cellulose adhesion forces are about an order of magnitude higher for PP film treatments at 13.56 MHz than at 40 kHz owing to much higher chain scission at lower frequencies, although it probably also occurs at high frequency and high power. Polypropylene powder treated with oxygen plasmas in optimum conditions for polar group incorporation did not result in improvement in any composite mechanical property, probably owing to the polymer melting. Sisal fibers and PP powder treated in conditions of surface degradation did not improve flexural or tensile properties but resulted in higher impact resistance, comparable to the improvement obtained with the addition of compatibilizer.
TL;DR: Itaconic acid (IA) was grafted onto sisal fibers using potassium persulfate as initiator and the effect of the monomer, initiator concentration, and reaction temperature on the grafting percentage has been investigated as discussed by the authors.
Abstract: Itaconic acid (IA) was grafted onto sisal fibers using potassium persulfate as initiator. The effect of the monomer, initiator concentration, and reaction temperature on the grafting percentage has been investigated. Evidence of the grafting process has been shown using IR spectroscopy and a scanning electron microscope. The tensile strength and thermogravimetric analyses for ungrafted and grafted samples with various degrees of grafting have also been investigated. The effect of grafting percent on the dyeability of grafted sisal fibers with basic dye has been studied.
TL;DR: In this article, the impact performance of sisal fiber reinforced epoxy composites was analyzed by using a surface tensiometer and dynamic mechanical analyzer, and the results indicated that the chemical treatments brought about strong bonding between sisal bundles and the epoxy matrix.
Abstract: To obtain comprehensive knowledge of the interfacial effect on the impact performance of sisal fiber reinforced epoxy composites, the fiber surface was modified in different ways prior to compounding. By using a surface tensiometer and dynamic mechanical analyzer, interfacial interactions in the composites were characterized. The results indicated that the chemical treatments brought about strong bonding between sisal bundles and the epoxy matrix. The subsequent impact tests revealed that the microfailure mechanism involved is a function of interfacial adhesion and fiber length continuity (i.e., continuous or discontinuous fiber). In the case of unidirectional laminates, an optimum fiber treatment should be able to result in an increased affinity between fiber bundles and matrix and a decreased intercellular adhesion. In this way, extension and uncoiling of the spirally arranged microfibrils, a main energy consumption process of plant fibers, can impart significant toughness to the composites. For short fiber composites, the interfacial strength should be properly tailored so as to increase energy dissipation through debonding and pull-out of fiber bundles.
TL;DR: In this article, the factors that influence in-plane mechanical responses and mode I interlaminar fracture toughness of stitched unidirectional sisal/epoxy laminates were studied.
Abstract: The factors that influence in-plane mechanical responses and mode I interlaminar fracture toughness of stitched unidirectional sisal/epoxy laminates were studied in this paper. It was found that in-plane strength and stiffness of the laminates were not significantly affected by the stitching threads, while the interlaminar toughness was greatly improved, especially at higher sisal content. Unlike glass fiber reinforced polymer composites, sisal laminates have a rather high tolerance against the damages induced by stitching process. In addition, stitching expanded the fiber bridging zone and determined the R-curve profiles of sisal laminates. Factors including stitching density, diameter and species of stitching thread, continuity of stitching, and modification methods of sisal, were proved to greatly influence the delamination resistance of the laminates.
TL;DR: In this article, an unsaturated polyester/sisal composite was formulated to achieve UL 94 V-0 performance using decabromine diphenyl oxide associated with antimony trioxide as additives.
TL;DR: In this article, the water absorption behavior of sisal and its epoxy based composites and the mechanical properties of composites that have been aged in water were discussed and a series of fibre pretreatment techniques, including mercerization, acetylation, cyanoethylation, coupling agent treatment and thermal treatment, were evaluated.
Abstract: The authors discuss the water absorption behaviour of sisal and its epoxy based composites and the mechanical properties of composites that have been aged in water. In addition, a series of fibre pretreatment techniques, including mercerization, acetylation, cyanoethylation, coupling agent treatment and thermal treatment, which are believed to be able to improve the water resistance of sisal and its composites, have been evaluated. It was found that the water absorption behaviour of sisal composites is controlled mainly by the fibre and the fibre/matrix interfacial characteristics. As a result, appropriate fibre modification to retard water diffusion and enhance interfacial adhesion is necessary if the natural fibre composites are to be used in practical applications.
01 Jan 2002
TL;DR: A sisal fiber has microstructures very different from those of synthetic fibres as mentioned in this paper, which consist of parallel cells and a cuticle-interface in the form of a continuous network.
Abstract: A sisal fibre has microstructures very different from those of synthetic fibres. The special microstructures consist of parallel cells and a cuticle-interface in the form of a continuous network ar...
01 Jan 2002
TL;DR: In this article, a summary of the recent developments of sisal reinforced composites is presented, including structure property relationships and surface modification techniques of the fiber as well as influencing factors of mechanical performance of the composites.
Abstract: In recent years, sisal fiber has been widely used as reinforcement of polymer composites due to its renewability, cost effectiveness, low density, high specific strength and modulus. This paper presents a summary of the recent developments of sisal reinforced composites. Structure property relationships and surface modification techniques of the fiber as well as influencing factors of mechanical performance of the composites are reviewed. It is believed that a right combination of fabrication techniques so far developed in accordance with different applications and target user groups should be found out.
01 Jan 2002
TL;DR: The papermaking potential of sisal fiber as a nonwood raw material was evaluated in this article, where chemical and morphological characteristics, as well as, the appropiate cooking conditions for pulping using the soda AQ process were determined.
Abstract: The papermaking potential of sisal fiber as a nonwood raw material was evaluated. The chemical and morphological characteristics, as well as, the appropiate cooking conditions for pulping using the soda AQ process were determined. Furthermore, values for the physical and mechanical properties of the sisal pulp were obtained. Unitary production costs were estimated for this process. The sisal fiber posseses a low lignin content but a high cellulose and hemicellulose content. The yield for the sisal pulping is higher than for wood fibers evaluated under similar pulping conditions. The tear and burst strength for the sisal fiber was greater than for caribean pine fibers, but tensile strength was similar. The estimated variable costs for production of the sisal pulp are lower than the ones reported in the literature for industrial trials, and slightly higher than for softwood fibers. The better fiber quality found in the sisal pulp can compensate its greater cost as a raw material.
Dissertation•
30 Nov 2002
TL;DR: In this paper, Sisal strands were chemically treated and incorporated into cement to produce sheeting suitable for housing, and results from mechanical strength tests indicated Sisal reinforced cement was suitable for construction of dwelling walls or roofs.
Abstract: The aim of this project was to investigate the properties of natural fibre reinforced (Sisal) cement sheeting. Sisal strands were chemically treated and incorporated into cement to produce sheeting suitable for housing. Results from mechanical strength tests indicated Sisal reinforced cement was suitable for construction of dwelling walls or roofs.
Patent•
15 May 2002
TL;DR: In this article, a preparation method for grafting polyacrylonitrile on natural sisal hemp fiber through ferther process of soaking in the solution of hydroasine hydrate, amino hydrozonation structured and alkaline hydrolysis is presented.
Abstract: This invention relates to a preparation method for grafted antibacterial sisal hemp fibre The said method includes grafting polyacrylonitrile on natural sisal hemp fibre through ferther process of soaking in the solution of hydroasine hydrate, amino hydrozonation structured and alkaline hydrolysis By controlling the condition of grafting reactuion, the concentration of hydrasine hydrate soakingsolution, the soaking time and the rate of plunging into liquid and regulating the temp and time of aminohydrazonation structured and the intensity of alkaline hydrolysis, the prepared anti-bacterial fibre is made to have a certain strength and grafted quantity of polyacrylonitrile, and at the same time, to contain different categories and contents of chemical functional groups on the surface, and has wide-spectrum antibacterial property and can high-effectively and durably kill bacteria or depress their growth
01 Jan 2002
TL;DR: In this paper, the effects of degumming using sodium hydroxide (NaOH) in softening sisal fibres for prospects in textile production were explored. And the results suggest that sisal could be explored in producing other textile products, such as bags, hats and rugs.
Abstract: The purpose of the study was to explore the effects of degumming using sodium hydroxide (NaOH) in softening sisal fibres for prospects in textile production. Based on reviewed literature on chemical degumming, it was hypothesized that an increase in NaOH concentration in the treatment solution will result in fibres with decreased breaking strength, linear density, stiffness and increased apparent elongation. A completely randomized experimental research design was used in this study, starting with a set of preliminary tests to determine the concentrations used in the actual experiment. Results revealed that with increased alkali concentration the breaking strength, linear density, stiffness, and apparent elongation were decreased. The optimal concentration of NaOH for degumming sisal was identified at 0.125N. At the optimal level, the breaking strength and apparent elongation were significantly decreased. Linear density of fibres and fibre stiffness were also decreased but not significantly. There was more fibre release from the binding materials at the optimal concentration, and the stain colour of the fibres was closer to cotton indicating more cellulose content. Sisal fibres were successfully degummed and foftened using NaOH. The results suggest that sisal could be explored in producing other textile products, such as bags, hats and rugs. 1 Food Science Department, Faculty of Agriculture, University of Swaziland, P/B Luyengo, Luyengo, Swaziland
01 Jan 2002
TL;DR: The research results showed that these sisal based activated carbon fibers supporting zinc have stronger antibacterial activity against Escherichia coli and S. aureus.
Abstract: Several kinds of activated carbon fibers, using sisal fiber as precursors, were preparedwith steam activation or with ZnCl2 activation. Zinc or its compounds were dispersed in them. Theantibacterial activities of these activated carbon fibers were determined and compared. The researchresults showed that these sisal based activated carbon fibers supporting zinc have strongerantibacterial activity against Escherichia coli and S. aureus. The antibacterial activity is related tothe precursors, the pyrolysis temperature, and the zinc content. In addition, small quantity of silversupported on zinc-containing ACFs will greatly enhance the antibacterial activity of ACFs.
01 Jan 2002
TL;DR: In this article, the design and construction of a sisal decorticator for small-scale farmers is described and the prototype provides for improved sisal processing and can be manufactured locally.
Abstract: The design and construction of a prototype sisal decorticator for small-scale farmers is
described. The prototype provides for improved sisal processing and can be manufactured
locally. Production capacity of the prototype 12 kg of dry sisal fiber per hour with a
design efficiency of 42.9% and yield of 3.2%. Test results show that after decortications,
sisal fibers have to be washed, dried and brushed in order to detach some pulp that may
have remained on the fibers.
Journal Article•
TL;DR: A comparison of the theoretical and experimental investigations on the compressive strength and elastic modulus of coir and sisal fibre reinforced concretes for various fibre-volume contents are presented in this paper.
Abstract: In this paper a comparison of the theoretical and experimental investigations on the compressive strength and elastic modulus of coir and sisal fibre reinforced concretes for various fibre-volume contents are presented. Law of mixtures is used for the theoretical computation of the elastic modulus of the above Natural Fibre Reinforced Concretes (NFRCs). It is observed that both the experimental and theoretical values of elastic modulus of NFRCs have shown 15% discrepancy, which can be regarded as comparatively small, as the mix is designed for a low volume of voids (ie. 2%). It is also found that at low fibre-volume contents, the theoretical and experimental results are very close. it is observed that the maximum compressive strengths are obtained at the same fibre-volume content i.e. @ 0.5%, by both the methods.