review article a review on natural fiber reinforced...

Review ArticleA Review on Natural Fiber Reinforced PolymerComposite and Its Applications

Layth Mohammed1 M N M Ansari1 Grace Pua1

Mohammad Jawaid2 and M Saiful Islam3

1Centre for AdvanceMaterials Department ofMechanical Engineering Universiti TenagaNasional 43000Kajang SelangorMalaysia2Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products (INTROP)Universiti Putra Malaysia (UPM) 43400 Serdang Selangor Malaysia3Department of Chemistry Faculty of Science Universiti Putra Malaysia (UPM) 43400 Serdang Selangor Malaysia

Correspondence should be addressed to M N M Ansari ansariunitenedumy

Received 18 February 2015 Revised 29 June 2015 Accepted 30 August 2015

Academic Editor Adriana Kovalcik

Copyright copy 2015 Layth Mohammed et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendlynature and sustainability The aim of this review article is to provide a comprehensive review of the foremost appropriate as wellas widely used natural fiber reinforced polymer composites (NFPCs) and their applications In addition it presents summary ofvarious surface treatments applied to natural fibers and their effect on NFPCs properties The properties of NFPCs vary with fibertype and fiber source as well as fiber structureThe effects of various chemical treatments on themechanical and thermal propertiesof natural fibers reinforcements thermosetting and thermoplastics composites were studied A number of drawbacks of NFPCslike higher water absorption inferior fire resistance and lower mechanical properties limited its applications Impacts of chemicaltreatment on the water absorption tribology viscoelastic behavior relaxation behavior energy absorption flames retardancy andbiodegradability properties of NFPCs were also highlighted The applications of NFPCs in automobile and construction industryand other applications are demonstrated It concluded that chemical treatment of the natural fiber improved adhesion between thefiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs

1 Introduction

Theincrease in environmental consciousness and communityinterest the new environmental regulations and unsustain-able consumption of petroleum led to thinking of theuse of environmentally friendly materials Natural fiber isconsidered one of the environmentally friendly materialswhich have good properties compared to synthetic fiber [1]

A late current industry research identified that the world-wide natural fiber reinforced polymer composites industrysector reached U$21 billion in 2010 Current pointers arethat interest in NFPCs industry will keep on growing quicklyaround the world The utilization of NFPCs has expandedconsiderably in the shopper merchandise as developingindustry sectors throughout the last few years As indicatedby evaluations over 5 years (2011ndash2016) the NFPCs industryis estimated to grow 10 worldwide [2]

Natural fibers in simple definition are fibers that are notsynthetic or manmade They can be sourced from plants oranimals [3] The use of natural fiber from both resourcesrenewable and nonrenewable such as oil palm sisal flaxand jute to produce composite materials gained considerableattention in the last decades so farThe plants which producecellulose fibers can be classified into bast fibers (jute flaxramie hemp and kenaf) seed fibers (cotton coir and kapok)leaf fibers (sisal pineapple and abaca) grass and reed fibers(rice corn and wheat) and core fibers (hemp kenaf andjute) as well as all other kinds (wood and roots) [4]Themostcommon and commercially natural fibers in the world andworld production have been shown in Table 1

Fiber reinforced polymer matrix got considerable atten-tion in numerous applications because of the good propertiesand superior advantages of natural fiber over syntheticfibers in term of its relatively low weight low cost less

Hindawi Publishing CorporationInternational Journal of Polymer ScienceVolume 2015 Article ID 243947 15 pageshttpdxdoiorg1011552015243947

2 International Journal of Polymer Science

Table 1 Natural fibers in the world and their world production [4]

Fiber source World production (103 ton)Bamboo 30000Sugar cane bagasse 75000Jute 2300Kenaf 970Flax 830Grass 700Sisal 375Hemp 214Coir 100Ramie 100Abaca 70

damage to processing equipment good relative mechani-cal properties such as tensile modulus and flexural mod-ulus improved surface finish of molded parts compositerenewable resources being abundant [5] flexibility duringprocessing biodegradability and minimal health hazardsNFPCs with a high specific stiffness and strength can beproduced by adding the tough and light-weight natural fiberinto polymer (thermoplastic and thermoset) [6] On theother hand natural fibers are not free from problems andthey have notable deficits in properties The natural fibersstructure consists of (cellulose hemicelluloses lignin pectinand waxy substances) and permits moisture absorption fromthe surroundings which causes weak bindings between thefiber and polymer Furthermore the couplings betweennatural fiber and polymer are considered a challenge becausethe chemical structures of both fibers and matrix are vari-ous These reasons for ineffectual stress transfer during theinterface of the produced composites Accordingly naturalfiber modifications using specific treatments are certainlynecessary These modifications are generally centered on theutilization of reagent functional groups which have abilityfor responding of the fiber structures and changing theircomposition As a result fiber modifications cause reductionof moisture absorption of the natural fibers which lead to anexcellent enhancement incompatibility between the fiber andpolymer matrix [7]

The wide applications of NFPCs are growing rapidlyin numerous engineering fields The different kinds of nat-ural fibers reinforced polymer composite have received agreat importance in different automotive applications bymany automotive companies such as German auto compa-nies (BMW Audi Group Ford Opel Volkswagen Daim-ler Chrysler and Mercedes) Proton company (Malaysiannational carmaker) and Cambridge industry (an auto indus-try in USA) Beside the auto industry the applications ofnatural fiber composites have also been found in buildingand construction industry sports aerospace and others forexample panels window frame decking and bicycle frame[8]

In a review of chemical treatments of natural fibers Kabirand coworkers [9] concurred that treatment is an importantfactor that has to be considered when processing natural

fibers They observed that fibers loose hydroxyl groupsdue to different chemical treatments thereby reducing thehydrophilic behavior of the fibers and causing enhancementin mechanical strength as well as dimensional stability ofnatural fiber reinforced polymer composites Their generalconclusion was that chemical treatment of natural fibersresults in a remarkable improvement of the NFPCs

2 Natural Fiber ReinforcedComposites (NFPCs)

Natural fiber polymer composites (NFPC) are a compositematerial consisting of a polymer matrix embedded withhigh-strength natural fibers like jute oil palm sisal kenafand flax [10] Usually polymers can be categorized intotwo categories thermoplastics and thermosetsThe structureof thermoplastic matrix materials consists of one or twodimensional moleculars so these polymers have a tendencyto make softer at an raised heat range and roll backtheir properties throughout cooling On the other handthermosets polymer can be defined as highly cross-linkedpolymers which cured using only heat or using heat andpressure andor light irradiation This structure gives tothermoset polymer good properties such as high flexibilityfor tailoring desired ultimate properties great strength andmodulus [3 4] Thermoplastics widely used for biofibers arepolyethylene [11] polypropylene (PP) [12] and poly vinylychloride (PVC) hereas phenolic polyester and epoxy resinsare mostly utilized thermosetting matrices [10] Differentfactors can affect the characteristics and performance ofNFPCsThehydrophilic nature of the natural fiber [5] and thefiber loading also have impacts on the composite properties[13] Usually high fiber loading is needed to attain goodproperties of NFPCs [14] Generally notice that the rise infiber content causes improving in the tensile properties ofthe composites [8] Another vital factor that considerablyimpacts the properties and surface characteristics of thecomposites is the process parameters utilized For that reasonappropriate process techniques and parameters should berigorously chosen in order to get the best characteristicsof producing composite [10] The chemical composition ofnatural fibers also has a big effect on the characteristics ofthe composite represented by the percentage of cellulosehemicellulose lignin and waxes Table 2 shows the chemicalcomposition of some common natural fibers [4]

Many researchers [8 11 15ndash17] have examined andresearched the suitability competitiveness and capabilitiesof natural fibers embedded in polymeric matrices Theresearchers [4 18 19] concentrated on the effect of the fibersurface modifications as well as manufacturing processes inimproving fiberpolymer compatibility On the other handsome researchers studied and compared between differentnatural fiber composites and their stability in various applica-tions [20] Al-Oqla and Sapuan [20] investigated the proper-ties of juteplastic composites such as crystallinity fibermod-ification thermal stability weathering resistance durabilityin addition to their suitability to the automotive industrythroughout ecodesign components while Mohanty et al [21]studied the effects of jute fiber on the mechanical properties

International Journal of Polymer Science 3

Table 2 Chemical composition of some common natural fibers [4]

Fiber Cellulose (wt) Hemicellulose (wt) Ligning (wt) Waxes (wt)Bagasse 552 168 253 mdashBamboo 26ndash43 30 21ndash31 mdashFlax 71 186ndash206 22 15Kenaf 72 203 9 mdashJute 61ndash71 14ndash20 12-13 05Hemp 68 15 10 08Ramie 686ndash762 13ndash16 06ndash07 03Abaca 56ndash63 20ndash25 7ndash9 3Sisal 65 12 99 2Coir 32ndash43 015ndash025 40ndash45Oil palm 65 mdash 29 mdashPineapple 81 mdash 127 mdashCuraua 736 99 75 mdashWheat straw 38ndash45 15ndash31 12ndash20 mdashRice husk 35ndash45 19ndash25 20 mdashRice straw 41ndash57 33 8ndash19 8ndash38

of pure biodegradable polymer (Biopol) the mechanicalproperties of the resulted composites impact strength tensilestrength and bending strength showed an increase whencompared with pure Biopol The tensile strength of juteBiopol was enhanced by 50 while bending strength andimpact strength of the composites were enhanced by 30 and90 in comparison to pure Biopol

3 General Characteristics of NFPCs

The properties of natural fiber composite are different toeach other according to previous studies because of differentkinds of fibers sources and moisture conditions The per-formance of NFPCs relies on some factors like mechanicalcomposition microfibrillar angle [20] structure [10] defects[22] cell dimensions [23] physical properties [4] chemicalproperties [24] and also the interaction of a fiber with thematrix [25] Since every product in market has drawbackssimilarly natural fiber reinforced polymer composites alsohave drawbacks The couplings between natural fiber andpolymer matrix are problem taken into consideration as aresult of the difference in chemical structure between thesetwo phases This leads to ineffective stress transfer duringthe interface of the NFPCs Thus the chemical treatmentsfor the natural fiber are necessary to achieve good interfaceproperties The reagent functional groups in the chemicaltreatments have ability to react on the fiber structures andalter the fiber composition [9] Natural fibers include afunctional group named as hydroxyl group which makes thefibers hydrophilic During manufacturing of NFPCs weakerinterfacial bonding occurs between hydrophilic natural fibreand hydrophobic polymer matrices due to hydroxyl groupin natural fibres This could produce NFPCs with weakmechanical and physical properties [8]

31 Mechanical Properties of the NFPCs There are consider-able enhancement and suggestions for the natural fibers that

can be implemented in order to enhance their mechanicalproperties resulting in high strength and structure Once thebase structures are made strong the polymers can be easilystrengthened and improved [26]There are number of aspectsthat effects of composite are performance level or activities ofwhich to name a few are the following

(a) orientation of fiber [5](b) strength of fibers [8](c) physical properties of fibers [27](d) interfacial adhesion property of fibers [28] and many

more

NFPCs are such composites whose mechanical efficiencyis dependent upon the interface provided by fiber-matrixalong with the stress transfer function in which stress istransferred to fiber from matrix This has been reported bymany investigators in several researches [1 23 29] Charac-teristic components of natural fibers such as orientation [30]moisture absorption [31] impurities [32] physical properties[33] and volume fraction [34] are such features that play aconstitutive role in the determination of NFPCs mechanicalproperties Mechanical properties of PLA epoxy PP andpolyester matrices can be affected by many types of naturalfibers and to show some of them Figure 1 is included

NFPCs show even better mechanical properties than apure matrix in cases where jute fibers are added in PLA(polylactic-acid) in this case 758 of PLArsquos tensile strengthwas improved however introduction or incorporation of flaxfibers showed anegative impact on this additionThe additionof flax fibers resulted in 16 reduced tensile strength of thecomposites Conversely composites of PP were improvedwith the incorporation of hemp kenaf and cotton [5] Byfar maximum improvement is only seen in such compositeswhere jute or polyester has been incorporated where a total of121 improvement is evident compared to pure polyester [5]


Table 3 Physicomechanical properties of natural fibers [38]

Fiber Density (gcm3) Tensile strength (MPa) Youngrsquos modulus (GPa) Elongation at break ()OPEFB 07ndash155 248 32 25Flax 14 88ndash1500 60ndash80 12ndash16Hemp 148 550ndash900 70 16Jute 146 400ndash800 10ndash30 18Ramie 15 500 44 2Coir 125 220 6 15ndash25Sisal 133 600ndash700 38 2-3Abaca 15 980 mdash mdashCotton 151 400 12 3ndash10Kenaf (bast) 12 295 mdash 27ndash69Kenaf (core) 021 mdash mdash mdashBagasse 12 20ndash290 197ndash271 11Henequen 14 430ndash580 mdash 3ndash47pineapple 15 170ndash1672 82 1ndash3Banana 135 355 338 53

PLA

PLA

Lju

te

PLA

flax PP

PPk

enaf

PPh

emp

PPc

otto

n

Epox

y

Epox

yju

te

Poly

este

r

Poly

este

rju

te

Tensile strengthCompressive strengthModulus of elasticity

Flexural strengthFlexural modulus

0

20

40

60

80

100

120

140

160

Mod

ulus

(GPa

)

0

20

40

60

80

100

120

140

Stre

ngth

(MPa

)

Figure 1 Some of mechanical properties of natural fiber reinforcedpolymer composite [5]

However due to the rubber phase present in gum compounda greater range of flexibility is present in suchmaterials whichresults in reduced stiffness and storage modulus

It is also known that stiffness and stress transfer incomposites increases with an increased or excessive additionof fiber which provides a better lossmodulus and also a betterstorage modulus The loss modulus is also considered to beincreased with fiber addition up to 756MPa at 50 phr fiberloading compared to the loss modulus of gum that is 415MPa[8]

A group of researchers led by Ismail et al [37] studiedthe effect of size and filler content on fiber characteristicsthat cures a wound or any part of the body Along withthis mechanical properties of Oil PalmWood Flour (OPWF)was also examined which is reinforced with (ENR) epox-idized natural rubber composites When the fiber contentis increased torque of the fibers is also increased and withsmallest possible particle size of OPWF highest torque

was noticed However increasing the factor of OPWF inENR compounds showed reduced tensile strength and whilereaching the break point a considerable elongation is evidentIt also evident increase in elongation tear strength tensilemodulus and hardness due to higher loading of OPWF Ahigher tensile strength and tear strength as tensile moduluswere identified in composites that were filled with evensmallest proportion of OPWF [10] The fracture behavior ofcomposites is also affected due to the nonlinear mechanicalbehavior of natural fibers under the influence of tensile-shear loads [1] Table 3 shows the mechanical properties forcommon types of natural fiber in the world [38]

The bonding strength between fiber and polymer matrixin the composite is consider a major factor in order to getsuperior fiber reinforcement composites properties Becauseof pendant hydroxyl and polar groups in fiber this leads toextremely highmoisture absorption of fiber resulting inweakinterfacial bonding between the fiber and the hydrophobicmatrix polymers To develop composites with good mechan-ical properties chemical modification of fibre carried out toreduce the hydrophilic behavior of fibers and the absorptionof moisture [15 39]

The different surface treatments of advanced compositesapplications were reviewed by several researchers [40ndash42]The effects of different chemical treatments on cellulosicfibers that were employed as reinforcements for thermoplas-tics and thermoset were also examined For the treatmentsthe different kinds of chemical treatment include silane[43] alkali [44] acrylation [45] benzoylation [46] maleatedcoupling agents [47] permanganate [48] acrylonitrile andacetylation grafting [49] stearic acid [50] peroxide [51]isocyanate [52] triazine [53] fatty acid derivate (oleoylchloride) sodium chloride and fungal [9] The main pur-pose of surface treatments of natural fibers to enhancedfibrematrix interfacial bonding and stress transferability ofthe composites

The impact of alkaline treatment on surface proper-ties of Iranian cultivated natural fibers was studied by


Cordeiroa et al [54] The research revealed that alkalinetreatment gets rid of some chemical components on thesurface of the fibers comprising uranic acid (hemicellulose)aromatic moieties (extractives) and nonpolar moleculesfrom the partial lignin depolymerisation There is a strongereffect on chemical components of nonwood fibers Improvingthe crystallinity of nonwood fibers in the softwood fibersresult in only aminor increase Hence alkaline treatment canresult in a remarkable improvement in the specific interactionof the fibers as well as improving the fibersrsquo wettability

Le Troedec et al [55] revealed the effects of somechemical treatments comprising ethylenediaminetetraaceticacid (EDTA) NaOH polyethylene imine (PEI) CaCl

2 and

Ca(OH)2 The effects were on the mechanical properties

of the composite materials from mixtures of hemp fiberand lime by differential thermal evaluation and tests Theobservation was that every treatment had a direct effect onthe fiber surface The treatment was with 6 NaOH and ledto cleaning fibers by removing the amorphous compoundsand the increase of the crystallinity index of fiber bundleswhile the EDTA treatment led to separates fibers and complexcalcium ions related to pectins In brief PEI treatment showsall studied properties an intermediate character and limewater treatment depicts calcium ionsrsquo fixation at the surfaceof fibers in comparison to a calcium chloride treatment whichdoes not

May-Pat et al [1] reported on the impact of the inter-phase properties from well controlled surface treatment inthe case of natural fibers The fracture behavior and themechanical properties of a NFPC depend on the propertiesof constituents and region of the fiber surface or interphasewhere the stress transfer occurs Furthermore the tailoringof the interphase by different kinds of surface treatmentsand carefully characterizing it provides a better knowledgeof the behavior of the NFPCs Moreover different fibersurface treatments modify the natural fiber microstructurespecifically under high loading rates

Venkateshwaran et al [35] studied the effect of alkali(NaOH) treatments of various concentrations (05 12 5 10 15 and 20) on the mechanical propertiesof bananaepoxy composite The results reported that ascompared to other treated and untreated fiber composites 1NaOH treated fiber reinforced composites have a better prop-erties The alkali concentration on the fiber surfaces resultsin better mechanical properties of the resulted compositeHowever the rising of alkali concentration maybe causesfiber surface damage leading to a decrease of mechanicalproperties The effect of different chemical treatment on themechanical properties and characteristic of sisal-oil palmhybrid fiber reinforced natural rubber composites have beenstudied by John et al [56] With chemical treatment thetorque values increased which lead to greater crosslinkingSimilarly alkali treatment showed a rise in the compositesrsquotensile strength in comparison to untreated composites andwith 4 NaOH treated fibers optimum tensile strength wasseen for resulted composites In contrast for compositestreated with 4 NaOH a strong interface is apparent becauseof a more superior adhesion between rubber and fiber ispresentwhich avoids solvent entry and a little swelling occurs

Van de Weyenberg et al [24] examined the impactof flax processing parameters and the fiber treatment onthe mechanical properties of flax fiber reinforced epoxycomposites It was discovered that the employment of longflax slivers may not necessarily lead to more superior com-posite properties The highest enhancement of the flexuralproperties of the flax fiber reinforced epoxy composites canbe gotten by chemical treatments There was an increase oftransverse strength of up to 250 and transverse modulusof up to 500 In addition the longitudinal properties ofthe UD composites (both modulus and strength) showedimprovements with 40 or more

Some modifications in the chemical and physical prop-erties of the lignocellulosic fibers can be observed after thetreatment of the fiber of rubber wood with laccase enzymesThese chemical treatments lead to the amorphous lignincontent changing the hemicellulose content and ultimatelythe natural crystallinity [57] The fiber has treatment effecton morphological and single fiber tensile strength of EFBfiber The EFB fiber treated with boiling water 2 sodiumhydroxide (NaOH) and mixing of boiling water and NaOHwas examined by Norul Izani et al [13] It was revealed that itchanged the properties of the fiber surface topography afterthe treatment Compared to untreated EFB fiber the treatedEFB fibers with the two types of treatment weremore thermalstability On the other hand the tensile strength and Youngrsquosmodulus of the treated fiber showed a rise in comparison tountreated fibers For tensile modulus the alkaline treatmenthas enhanced the tensile properties of sugar palm fiberreinforced epoxy composites at better soaking times andconcentrations of alkaline On the other hand the increasethe alkaline concentration may lead to fiber damage [58]

Acrylonitrile Butadiene Styrene (ABS) with the coatingeffect of OPEFB fibers was tested BT The coated processenhanced the mechanical and physical properties and alsoimproved the fiber performance The ABS treatment ledto reducing the water absorption and also decreased thebiodegradation potential of the fiber in contact with soilWith the coating the tensile strength and elasticity moduliof the OPEFB fibers became better than what they were inthe past The surface area between fiber and soil particlesincreased by coating fiber which led to improving the shearstrength parameters of the fiber reinforced soils [66]

32 Flame Retardant Properties of the NFPCs Due to eco-friendly and sustainability nature natural fiber compositesprefers as compared to conventional synthetic fibre basedcompositesThey are applied in diversified domains [9 18 2038 67] such as building materials [68] aerospace industryand automotive industry [69] Natural fibers and polymersare organic materials and are very sensitive to alter anyfeatures if flame is introduced to them Flame retardancy isanother aspect that has become greatly significant in orderto fulfill safety measures taken while developing natural fibercomposites

In the presence of flame burning of composites takesplace in five different steps as shown below

(a) Heating


(b) Decomposition(c) Ignition(d) Combustion(e) Propagation [70]

If flame retardancy has been achieved in the aforementionedsteps no matter whether ignition step has been conductedor not the procedure will be terminated before an actualignition is set up There are two forms of products that areobtained upon burning of composites these two includehigh cellulose content and high lignin content High celluloseprovides chances of higher flammability whereas highervalues of lignin show there is a greater chance of charformation [71] Thermal resistance is provided by flax fibers[72] however silica or ash is another important feature thatis helpful in extinguishing fire [73]

In order to enhance fire resistance of various NFPCsdifferent procedures are undertaken Fire barriers are kind ofbarriers that can be applied to phenolics ceramics intumes-cents glass mats silicone ablatives and chemical additivestoo Coatings and additives used in the system of intumescentare found to be very promising fire barrier treatments inwhich these barriers are expanded upon heating resulting in acellular surface that is charred evenHowever with the help ofthis charred surface internal or underlying components andprotected against flux and heat

One of the well-known or profound flame retardantsfor reinforced polymers (natural fibers) is used with thecombination of char developing cellulose material [74]The only method of reducing combustion in this scenariois through increasing stability and char formation in thepolymer This will result in reduced flammability decreasevisible smoke and restrict the volume of products produceddue to combustions [72] Fire retardant coating is anothermethod that helps in enhancement of fire resistance propertyof composites This coating is done at the end or finishingstage or impregnation Due to changes in the fibers and lingo-cellulosic particles fire resistance is altered during the processof manufacturing [75]

The two most widely used metal hydroxide flame retar-dants are known to be aluminum hydroxide [Al(OH

3)] and

magnesium hydroxide [Mg(OH)2] which are purposefully

added to polymers The chemical reaction through whichthese two flame retardants decompose are as follows

2Al (OH)3997888rarr Al

2O3+ 3H2O Δ119867 = 20 calg (1)

Mg (OH)2997888rarr MgO +H

2O Δ119867 = 328 calg (2)

Out of these two flame retardants magnesium hydroxidedisplay better thermal stability as compared to aluminumhydroxide since the temperature range given off by thedecomposition of magnesium hydroxide is nearly 300ndash320degrees centigrade (∘C) which is much higher than thetemperature range offered by aluminum hydroxide that isonly 200∘C For this reason aluminum hydroxide is notconsidered to be thermally stable as it cannot be used forpolyamides polypropylene or others whereas magnesiumhydroxide can be used

It was also shown in a research that the addition ofexpandable graphite (EG) and ammonium polyphosphate(APP) in composite polymer as a source of flame retardant(FR) helps in enhancing flax fiber reinforced PP compositersquosproperty of fire retardancy It was also shown that heat releaserate (HRR) in a composite additive of 30wt of flax fiber and25wt of EG (expandable graphite) was decreased to 35 from167 kWm2 [76]

Spirocyclic pentaerythritol bisphosphorate disphospho-ryl melamine (SPDPM) is a type of intumescent flameretardant for PLA that was studied by Zhan et al [77]Char formation that is a result of spirocyclic pentaerythritolbisphosphorate disphosphorylmelamine (SPDPM) an activecomponent of flame retardancy enhances antidripping per-formance of PLA and flame retardancy too with an additionof 25wt Flame retardancy is not an easy thing to beimparted and it is only possible if there is an extensive highloading of inorganic filler

Hapuarachchi and Peijs [78] studied the development offully bio-based natural fiber composite that has enhancedfeatures of fire or flame retardancy This natural fiber com-posite was developedwith the help of PLApolymers that werederived from crops accompanied with 2 kinds of nanofillerswhich are able to produce synergy corresponding to flameretardancy Upon analysis after incorporating hemp fibermat in PLA resin decrease in PHRR (peak heat release) incalorimeter will be shown

33 Biodegradability of the NFPCs High strength compositesare resultant products of natural fiber reinforcement in poly-mers which also provide extra or improved biodegradabilitylow cost light weight and enhanced properties related tomechanical structure [29] At temperatures as high as 240∘Cnatural fibers start degrading whereas constituents of fibersuch as hemicelluloses cellulose lignin and others startdegrading at different levels of temperature for example at200∘C lignin starts to decompose whereas at temperatureshigher than this other constituents will also degrade [9]

Since thermal stability of the fibers is dependent onthe structural constituents of fibers it can be improvedif the concentration levels or the structural constituentsare completely removed such as lignin and hemicellulosesThis can be achieved with the help of chemical treatmentsDevelopment of fibers and materials that provide servicesare two important aspects which should be consideredwhile degradating natural fibers [9] Natural fibers have ashort lifetime with minimum environmental damage upondegradation whereas synthetic ones affect environment dueto pollution caused by degradation Lignin hemicellulosesand cellulose concentrations or composition affect thermaldegradation features of lingo-cellulosic materials [13] Morethan fifty percent weight of jute or Biopol composite is lostafter exactly 1500 days of burial [21]

34 Energy Absorption of the NFPCs High strength energyabsorption and stiffness are obtained by composite materialswhich are widely used in automotive and motorsport sectorsof industrymainly due to the property ofmass reduction [79]


Enhanced energy absorption is evident from the increasedvolume fraction that is only possible in the presence oflow speed such as 25ms [80] On the other hand at highspeeds such as 300ms similar performance is shown byflax jute and hemp but jute showed brittleness and lowstrength of fibers [81] Potential of NFPCs that is requiredfor application in providing sustainable energy absorptionwas investigated by Meredith et al While keeping focus onmotorsport [80] Vacuum Assisted Resin Transfer Molding(VARTM) technique is used to test conical specimens of flaxjute and hemp for their properties and features Variousvalues exhibited by different kinds of materials were recordedto analyze specific energy absorption (SEA)

35 Tribology Properties of NFPCs Since every materialhas some wear and friction properties that degrade withrespect to time the tribological loadings are important toconsider for an improvedmechanical part design [5] Around90 failure is obtained due to differences in tribologicalloading conditions which alters their wear and frictionproperties [82] Reinforcement is a method with whichfiberrsquos or polymers tribological properties are altered (eitherpositively or negatively) [83] Studies on different kinds oftribological analysis have been conducted on fibers includingkenafepoxy [84] betelnut fiber reinforced polyester [85]sisalphenolic resin [86] sugarcane fiber reinforced polyester(SCRP) [87] and cottonpolyester [88] Improvement in wearperformance of PLA was evident due to the addition ofnatural fibers in which wear rate of composites was quite lowin comparison to wear rate at higher loads on neat PLA [82]

Kenaf fibers reinforced with epoxy composite were usedby Chin and Yousif [84] for a kind of bearing applica-tion in which they showed an 85 enhancement of wearperformance and normal orientation in composites Wearand friction features of glass fiberpolyester (GRP) andsugarcane fiberpolyester (SCRP) were studied by El-Tayebwith different parameters including speed the time taken fortest and load [87] The research results concluded SCRP as acompetitor of GRP composite The same characteristics werestudied by Xin et al [86] for sisal fiber reinforced resin brakecomposites which showed sisal fiber can be used instead ofasbestos in brake pads [89 90]

Laminated composites were developed with the help ofthree different natural fibers such as grewia nettle optivaand sisal This connection of natural fibers was studied byBajpai et al in which a hot compression procedure was usedto incorporate three different materials in a PLA polymer[82] Friction andwear features of composites were examinedunder different situations such as dry contact condition withvarying operating parameters Due to an option of variableoperating parameters applied load was varied in betweenrange of 10 to 30N with a speed ranging from 1 to 3ms andsliding distance of thousand to three thousand meters Theresearch results showed infusion of natural fibermats in PLAmatrix is capable of enhancing wear and frictional behaviorof neat polymers An approximate reduction of 10ndash44 in thecoefficient of friction with a greater reduction of 70 seen indeveloped composites for specific wear rate is visualized incomparison to neat PLA [82]

36 Water Absorption Characteristics of the NFPCs Naturalfibers work well as reinforcement in polymers Howeverthe main weakness of the application of natural fibers istheir susceptibility to moisture [91] Mechanical propertiesof polymeric composites have a strong dependence on theinterface adhesion between the fiber and the polymer matrix[15] The natural fibers are rich of cellulose hemicelluloseslignin and pectins all of which are hydroxy 1 groups thatis they are usually hydrophilic sources and strong polarwhilst polymers show considerable hydrophobicity Thusthere are major challenges of suitability between the matrixand fiber that weakens interface region between matricesand natural fibers [5] At the composite materialsrsquo outerlayers water absorption happens and decreases graduallyinto the bulk of the matrix A generally high water intakeby composite materials results in an increased weight ofwet profiles a conceivable decline in their strength andincrement in their deflection swelling and causing pressureon nearby structures These can cause warping bucklingbigger possibility of their microbial inhabitation freeze andunfreeze caused destruction of mechanical characteristics ofcomposite materials [92]

Oil palm fiber natural rubber (OPF-NR) compositesincreased in the water absorption percentage correspond-ing to an increase in fiber loading because of the fibersrsquohydrophilicity The absorption behavior of NR showed mod-ifications from Fickian to non-Fickian with additional OPFbecause of the microcracks and the viscoelastic nature of thepolymer [8] In the woven pandanusbanana fabric compos-ites tests woven pandanus fabric composites increased thewater uptake compared to woven banana fabric compositesbecause of higher lignin content and hemicellulose as wellas the presence of defects in the composite system [93]Furthermore temperature can affect the percentage of waterabsorption of the composites At 65 humidity at 21∘Cthe equilibrium moisture content of some natural fiber canbe observed in Table 4 [4] It was revealed that the waterabsorption of OPF-NR composite was less than of OPF-sisalfiber-NR hybrid biocomposite The incorporation of sisalfiber that contains relatively more holocellulose (23) whichis exceptionally hydrophilic brought on more water intakeBesides the lignin content material of OPF (19) was biggerthan sisal fiber (9) Lignin being hydrophobic reduces thewater absorption [8]

Many researchers [8 56] showed the effect of couplingagent such as maleic anhydride polyethylene and chem-ical treatments such as bleaching acetylation and alkalitreatment on reduction moisture absorption of NFPCs Thesurface of the fibers is cleaned during the chemical treatmentsto ensure there are no impurities which increases the fibersurface roughness and preventing the moisture absorptionvia the removal of the coat of OH groups of fiber as seen inequation below [5 9]

Fiber-OH + NaOH 997888rarr Fiber-OminusNa+ +H2O (3)

Sreekala and Thomas [91] investigated the moisture absorp-tion properties of OPEFB fiber in different temperature con-dition They also studied the effect of different modification


Table 4The equilibriummoisture content of different natural fiberat 65 relative humidity (RH) and 21∘C [4]

Fiber Equilibrium moisture content ()Sisal 11Hemp 90Jute 12Flax 7Abaca 15Ramie 9Pineapple 13Coir 10Bagasse 88Bamboo 89

onOPEFB fiber such as silane treatment gamma irradiationlatex coating mercerization acetylation peroxide treatmentand isocyanate treatment on moisture absorption propertiesThey concluded that all the treatment causes the seduction inmoisture absorption properties in all temperatures

The mercerization of OPF-sisal fiber-NR hybrid com-posites led to reducing water adsorption of the compositeby improving the adhesive characteristics of fiber surfaceand also providing a large surface area which causes bettermechanical interlocking [94] Shinoj et al [8] conductedthe effect of chemical treatment for agave fibers on mois-ture adsorption before blending in a polymer matrix Thechemical treatment is achieved using four types of reagentsacetic anhydride (Ac) maleic anhydride (MA) styrene (S)and acrylic acid (AA)This paper concludes that the chemicaltreatment causes decrease in the global diffusivity of waterand also concludes that the water mobility in the fiber coreis more than at the surface

37 Viscoelastic Behavior of the NFPCs Dynamic mechanicalmeasurements or the viscoelastic behavior over a range oftemperatures provides valuable insight into the structuremorphology and determination of the interface charac-teristics of natural fiber composite materials [95] Storagemodulus gives an insight into the load bearing capability andthe stiffness behavior of natural fiber composite materialsStorage modulus is a measure of the maximum energy storedin the material during one cycle of oscillation The mechan-ical damping coefficient is the ratio of the loss modulus tothe storage modulus and is related to the degree of molecularmobility in the polymeric material On the other hand lossmodulus is proportional to the amount of energy dissipatedas heat by the sample [96]

The viscoelastic behavior of novel commingled biocom-posites based on polypropylenejute yarns is reported by[96] By using commingling method jute yarn reinforcedpolypropylene commingled composites were prepared Theviscoelastic behavior or dynamic mechanical properties ofthe result commingled composites were studied according tothe fiber content and different kinds of chemical treatmentssuch as potassium permanganate (KMnO

4) maleic anhy-

dride modified polypropylene (MAPP) toluene diisocyanate

30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

1Hz

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

07

08

09

tan 120575

Figure 2 tan 120575 versus temperature curves of the alkali treated anduntreated composites at 1Hz frequency [35]

(TDI) and stearic acid (ST) This study concluded thatincreasing of fiber content leads to increasing the storage andloss modulus of the composite On the other hand at alltemperatures the chemical treatment by KMnO

4andMAPP

leads to increasing the storage modulus and loss modulus ofthe respective treated composites than the untreated ones

By using the dynamic mechanical analyzer Venkatesh-waran et al [35] studied the impact of alkali treatmentson the viscoelastic behavior of natural fiber composite Thecorresponding viscoelastic properties were determined asa function of temperature and frequency when the mea-surements were executed in the tensile mode of the usedequipment At the temperature range of 30ndash140∘Cat 01 1 and10Hz frequencies respectively the experiments executed thegraphs plotted as storage modulus (Eminus) versus temperatureand tan 120575 versus temperature as shown in Figures 2 and 3[35]

38 Relaxation Behavior of the NFPCs Natural fiber pos-sesses an intrinsic relaxation behavior which has a mainfunction in the stress relaxation of NFPCs Thus the tensilestress relaxation of the reinforcing fiber needs to be studied indetail [38] Sreekala et al [29] for instance did such a studyfocusing on the character of individual OPEFB fiber andin addition examined the fiber surface modification effectsageing and strain level on the fiber relaxation behavior Thefibers stress relaxation was lessened significantly with surfacetreatments like latex modification and thus decreasingresulting physical interaction between the latex particles andfiber surface Also water and thermal ageing reduce the rateof relaxation for the oil palm fiber the rate of stress relaxationof the OPEFB fiber was optimized at 10 strain level whichis shown in Figure 4 while the relaxation modulus valuesfor the fiber show similar trends as in the case of stressrelaxation as shown in Figure 5 On the other hand thestress relaxation rate ofOPF-sisal fiber-NRhybrid compositesshowed a reduction with an increase in fiber percentage[97]


30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575

Figure 3 tan 120575 versus temperature curves of alkali treated anduntreated composites [35]

TreatmentUntreatedSilaneLatex

Gamma irradiationTDIAcetylated

030

045

060

075

090

2 4310

log time (s)

120590t1205900

Figure 4 Stress relaxation curves of untreated and treated OPEFBfiber at 10 strain [29]

39 Thermal Properties of NFPCs The untreated OPFs arethermally more stable when compared with treated oneswhile OPF is considered thermally more stable compared toflax fibers and hemp fibers Increase of temperatures from20∘C to 150∘C causes increase of the heat capability of OPFsparticularly from 1083 J gminus1 ∘Cminus1 to 3317 J gminus1 ∘Cminus1 [98] Thethermal diffusivity thermal conductivity and specific heatof the flaxHDPE composites lessened with a rise in fibercompositionHowever the thermal conductivity and thermaldiffusivity showed no significant changes in the range of170ndash200∘C The biocompositesrsquo specific heat showed gradualincrease with temperature [4] By using polycarbonate togenerate functional composites pineapple leaf fiber wasthe support The changed pineapple leaf fibers composite

Fibre treatmentUntreatedSilaneLatex

Gamma irradiationIsocyanateAcetylated

2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)

Figure 5 Relaxation modulus curves of untreated and treatedOPEFB fiber at 10 strain [29]

treated with silane showed the impact strengths and highesttensile The compositesrsquo thermal stability is lower than theneat polycarbonate resin according to the thermogravimetricexamination Besides that the thermal stability lessened witha rise in pineapple leaf fiber composition [4]

Enzymatic treatment for many natural fibers such asflax and hemp often natural fibers can lead to improvementin surface and thermal properties [56] Hemicellulose andpectinase are the treatments which can improve the thermalproperties of the fibers mentioned The enzymes possess anattractive state for the improvement of the natural fibersrsquosurfaces for natural fiber composite application [67]

Norul Izani et al [13] studied the effect of chemicaltreatment on the morphological and tensile strength of theEFB fiberThe treatments were by the types of treatments 2sodium hydroxide (NaOH) and combination of both NaOHand boiling water The chemical treatment by NaOH led toenhancing the fiber surface topography thermal stability andtensile strength of the fiber while the chemical treatmentusing NaOH and water boiling caused the higher thermalproperties of the EFB fibers compared to untreated fibers

4 Natural Fiber PolymerComposites Application

The applications of NFPCs are growing rapidly in numerousengineering fieldsThedifferent kinds of natural fibers such asjute hemp kenaf oil palm and bamboo reinforced polymercomposite have received a great importance in differentautomotive applications structural components packingand construction [5 99] NFPCs are finding in electricaland electronic industries aerospace sports recreation equip-ment boats machinery office products and so forth Thewidespread application of NFPCs in polymer composites dueto its low specific weight relatively high strength relativelylow production cost resistance to corrosion and fatigue


Table 5 The application of natural fiber composites in automotive industry [59ndash62]

Manufacturer Model ApplicationRover 2000 and others Rear storage shelfpanel and insulationsOpel Vectra Astra Zafira Door panels pillar cover panel head-liner panel and instrumental panelVolkswagen Passat Variant Golf A4 Bora Seat back door panel boot-lid finish panel and boot-liner

Audi A2 A3 A4 A4 Avant A6 A8Roadstar Coupe

Boot-liner spare tire-lining side and back door panel seat back and hatrack

Daimler Chrysler A C E and S class EvoBus(exterior)

Pillar cover panel door panels car windshieldcar dashboard and businesstable

BMW 3 5 and 7 series and other Pilot Seat back headliner panel boot-lining door panels noise insulationpanels and moulded foot well linings

Peugeot 406 Front and rear door panels seat backs and parcel shelf

Fiat Punto Brava Marea Alfa Romeo146 156 159 Door panel

General Motors Cadillac De Ville Chevrolet TrailBlazer Seat backs cargo area floor mat

Toyota ES3 Pillar garnish and other interior partsSaturn L300 Package trays and door panelVolvo V70 C70 Seat padding natural foams and cargo floor trayFord Mondeo CD 162 Focus Floor trays door inserts door panels B-pillar and boot-linerSaab 9S Door panelsRenault Clio Twingo Rear parcel shelfToyota Raum Brevis Harrier Celsior Floor mats spare tire cover door panels and seat backsMitsubishi Cargo area floor door panels and instrumental panel

Mercedes BenzC S E and A classes

Door panels (flaxsisalwood fibers with epoxy resinUP matrix) glove box(cotton fiberswood molded flaxsisal) instrument panel supportinsulation (cotton fiber) molding rodapertures seat backrest panel(cotton fiber) trunk panel (cotton with PPPET fibers) and seatsurfacebackrest (coconut fibernatural rubber)

Trucks Internal engine cover engine insulation sun visor interior insulationbumper wheel box and roof cover

Citroen C5 Interior door panellingLotus Eco Elise (July 2008) Body panels spoiler seats and interior carpetsRover 2000 and others Insulation rear storage shelfpanel

VAUXHALL Corsa Astra Vectra Zafira Headliner panel interior door panels pillar cover panel and instrumentpanel

totally biodegradable improving the surface finish of moldedpart composites relatively goodmechanical properties avail-able and renewable sources as compared to synthetic fibers[5 98] On the other hand there is a physical disadvantage oftheNFPCs such asmoisture absorption restricted processingtemperature and variable quality and this disadvantage led tolimiting their performance [73]

41 Natural Fiber Composites Applications in the Interior CarMost of the car companies in the world have done a lot ofinvestigation in order to insert the NFPCs in their productsThe car manufacture in Europe has done various researchesto increase the applications of NFPCs in automotive industryespecially in car interior such as seat backs parcel shelvesboot linens front and rear door linens truck linens anddoor-trim panels [89] Beside the use for car interior partsin automobile industry natural fiber embedded in polymers

has been used for high requirement applications for exteriorauto body components such as the middle section betweenthe headlights above the fender of a passenger bus [18]

German auto companies (BMW Audi Group Ford OpelVolkswagen Daimler Chrysler and Mercedes) utilize thecellulose fibers composites in various automobile part shownin Figure 6 such as using coco nut fibers rubber latexcomposites for the seats of the Mercedes Benz A-class modeland using fax-sisal fiber mat reinforced epoxy door panelsof Mercedes Benz E-class model [8] Audi company usesflaxsisal mat reinforced polyurethane composite with a mixto make door trim panels [60] Ford is using kenaf fibersimported from Bangladesh in their ldquoMondeordquo model and thedoor panels of the Mondeo are manufactured from kenafreinforced PP composites while using flax in floor trays [61]Kenaf and flax mixture has gone into package trays and doorpanel inserts for Opel Vectras Volkswagen company used


Table 6 Natural fiber composite applications in industry [3 63ndash65]

Fiber Application in building construction and others

Hemp fiber Construction products textiles cordage geotextiles paper amp packaging furniture electrical manufacture banknotes and manufacture of pipes

Oil palm fiber Building materials such as windows door frames structural insulated panel building systems siding fencingroofing decking and other building materials [14]

Wood fiber Window frame panels door shutters decking railing systems and fencing

Flax fiber Window frame panels decking railing systems fencing tennis racket bicycle frame fork seat post snowboardingand laptop cases

Rice husk fiber Building materials such as building panels bricks window frame panels decking railing systems and fencingBagasse fiber Window frame panels decking railing systems and fencing

Sisal fiber In construction industry such as panels doors shutting plate and roofing sheets also manufacturing of paper andpulp

Stalk fiber Building panel furniture panels bricks and constructing drains and pipelines

Kenaf fiber Packing material mobile cases bags insulations clothing-grade cloth soilless potting mixes animal bedding andmaterial that absorbs oil and liquids

Cotton fiber Furniture industry textile and yarn goods and cordage

Coir fibersBuilding panels flush door shutters roofing sheets storage tank packing material helmets and postboxes mirrorcasing paper weights projector cover voltage stabilizer cover a filling material for the seat upholstery brushes andbrooms ropes and yarns for nets bags and mats as well as padding for mattresses seat cushions

Ramie fiber Use in products as industrial sewing thread packing materials fishing nets and filter cloths It is also made intofabrics for household furnishings (upholstery canvas) and clothing paper manufacture

Jute fiber Building panels roofing sheets door frames door shutters transport packaging geotextiles and chip boards

Figure 6Automobile componentsmade of natural fiber composites[36]

cellulose fiber to make Seatback door panel boot-lid finishpanel boot-liner in Passat Variant Golf A4 and Boramodel

BMW Group has a lot of NFPCs into its automobilesBMW Group used about 10 000 tonnes of natural fiber in2004 [100] Each BMW 7 series car boats 24 kg of renewableraw materials with flax and sisal in the interior door liningpanels Also use cotton in the soundproofing wool in theupholstery and wood fiber in the seat back Daimler-Benz inGermany is also working with a range of natural fibers plusmn sisaljute coconut European hemp and flax plusmn as reinforcing fibersin high-quality polypropylene components in order to replaceglass fibers Daimler-Benz has developed the dashboards andcenter armrest consoles alongwith seat shells and paneling onseat backs Moreover it increased the utilization of NFPCs insome automobiles by approximately 98 over earlier modelsby utilizing natural fibers for example abaca and flax Onthe other hand the Cambridge industry made rear shelf trim

panels of the 2000 model Chevrolet Impala using flax fiberpolypropylene composite [8 101] Toyota Proton Volvo andother automobile companies used cellulose fiber to make carparts as shown in Table 5

42 The Natural Fiber Applications in the Industry Otherthan the car industry the applications of NFPCs are foundin building and construction aerospace sports and moresuch as partition boards ceilings boats office products andmachineryThemost applications of NFPCs are concentratedon nonload bearing indoor components in civil engineeringbecause of their vulnerability to environmental attack [72]Green buildings are wanted to be ecologically mindfulsuitable and healthy place to live and work Biocompositesis consider one of the major materials utilized as a partof green materials at this time It could be categorizedwith regard to their application in the building marketinto two principle products firstly structural biocompositeswhich include bridge as well as roof structure and sec-ondly nonstructural biocomposites which include windowexterior construction composites panels and door frame[2]

The wide advantages of natural fibers reinforced compos-ites such as high stiffness to weight ratio lightweight andbiodegradability give them suitability in different applicationin building industries [102] Van de Weyenberg et al [24]have shown that good properties of thin walled elements suchas high strength in tension and compression made of sisalfiber reinforced composite give it a wide area of applica-tion for instance structural building members permanentformwork tanks facades long span roofing elements andpipes strengthening of existing structures On the other hand


bamboo fiber can be used in structural concrete elementsas reinforcement while sisal fiber and coir fiber compositeshave been used in roofing components in order to replaceasbestos [15] Natural fiber reinforced concretes productsin construction applications like sheets (both plain andcorrugated) and boards are light in weight and are ideal foruse in roofing ceiling andwalling for the construction of lowcost houses [103] Table 6 shows the various applications ofcellulose fiber in industry construction and other industries

5 Conclusions

Natural fiber reinforced polymer composites have bene-ficial properties such as low density less expensive andreduced solidity when compared to synthetic compositeproducts thus providing advantages for utilization in com-mercial applications (automotive industry buildings andconstructions) Using natural fibers as reinforcement forpolymeric composites introduces positive effect on themechanical behavior of polymers This paper evaluates thecharacteristics and properties of natural fiber reinforcedpolymer composites mechanical thermal energy absorp-tionmoisture absorption biodegradability flame retardancytribology properties Viscoelastic behavior and relaxationbehavior of NFPCs are researched Also the application ofNFPCs in automobile and industry is reported The effectsof chemical treatment of the natural fiber properties werealso addressed The physical and mechanical properties ofthese NFPCs can be further enhanced through the chemicaltreatment while moisture absorption of the NFPCs canbe reduced through surface modification of fibers such asalkalization and addition of coupling agents

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

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[2] N Uddin EdDevelopments in Fiber-Reinforced Polymer (FRP)Composites for Civil Engineering Elsevier 2013

[3] A Ticoalu T Aravinthan and F Cardona ldquoA review ofcurrent development in natural fiber composites for struc-tural and infrastructure applicationsrdquo in Proceedings of theSouthern Region Engineering Conference (SREC rsquo10) pp 113ndash117Toowoomba Australia November 2010

[4] O Faruk A K BledzkiH-P Fink andM Sain ldquoBiocompositesreinforced with natural fibers 2000ndash2010rdquo Progress in PolymerScience vol 37 no 11 pp 1552ndash1596 2012

[5] A Shalwan and B F Yousif ldquoIn state of art mechanicaland tribological behaviour of polymeric composites based onnatural fibresrdquoMaterials amp Design vol 48 pp 14ndash24 2013

[6] Y Xie C A S Hill Z Xiao H Militz and C Mai ldquoSilanecoupling agents used for natural fiberpolymer composites

a reviewrdquo Composites Part A Applied Science and Manufactur-ing vol 41 no 7 pp 806ndash819 2010

[7] S S Ray and M Bousmina ldquoBiodegradable polymers and theirlayered silicate nanocomposites in greening the 21st centurymaterials worldrdquo Progress in Materials Science vol 50 no 8 pp962ndash1079 2005

[8] S Shinoj R Visvanathan S Panigrahi andM Kochubabu ldquoOilpalm fiber (OPF) and its composites a reviewrdquo Industrial Cropsand Products vol 33 no 1 pp 7ndash22 2011

[9] M M Kabir H Wang K T Lau and F Cardona ldquoChemicaltreatments on plant-based natural fibre reinforced polymercomposites an overviewrdquo Composites Part B Engineering vol43 no 7 pp 2883ndash2892 2012

[10] H Ku HWang N Pattarachaiyakoop andM Trada ldquoA reviewon the tensile properties of natural fiber reinforced polymercompositesrdquo Composites Part B Engineering vol 42 no 4 pp856ndash873 2011

[11] F Z Arrakhiz M El Achaby M Malha et al ldquoMechanical andthermal properties of natural fibers reinforced polymer com-posites doumlow density polyethylenerdquo Materials amp Designvol 43 pp 200ndash205 2013

[12] G Di Bella V Fiore G Galtieri C Borsellino and A ValenzaldquoEffects of natural fibres reinforcement in lime plasters (kenafand sisal vs Polypropylene)rdquo Construction and Building Mate-rials vol 58 pp 159ndash165 2014

[13] M A Norul Izani M T Paridah U M K Anwar M Y MohdNor and P S HrsquoNg ldquoEffects of fiber treatment on morphologytensile and thermogravimetric analysis of oil palm empty fruitbunches fibersrdquo Composites Part B Engineering vol 45 no 1pp 1251ndash1257 2013

[14] I S M A Tawakkal M J Cran and S W Bigger ldquoEffect ofkenaf fibre loading and thymol concentration on the mechan-ical and thermal properties of PLAkenafthymol compositesrdquoIndustrial Crops and Products vol 61 pp 74ndash83 2014

[15] M J John and S Thomas ldquoBiofibres and biocompositesrdquoCarbohydrate Polymers vol 71 no 3 pp 343ndash364 2008

[16] E Jayamani S Hamdan M R Rahman and M K B BakrildquoComparative study of dielectric properties of hybrid naturalfiber compositesrdquo Procedia Engineering vol 97 pp 536ndash5442014

[17] C C Eng N A Ibrahim N Zainuddin H Ariffin andW M Z W Yunus ldquoImpact strength and flexural propertiesenhancement of methacrylate silane treated oil palm mesocarpfiber reinforced biodegradable hybrid compositesrdquo The Scien-tific World Journal vol 2014 Article ID 213180 8 pages 2014

[18] N Graupner A S Herrmann and J Mussig ldquoNatural andman-made cellulose fibre-reinforced poly (lactic acid)(PLA)composites an overview about mechanical characteristics andapplication areasrdquo Composites Part A Applied Science andManufacturing vol 40 no 6-7 pp 810ndash821 2009

[19] K Bocz B Szolnoki AMarosi T TabiMWladyka-Przybylakand G Marosi ldquoFlax fibre reinforced PLATPS biocompositesflame retarded with multifunctional additive systemrdquo PolymerDegradation and Stability vol 106 pp 63ndash73 2014

[20] F M Al-Oqla and S M Sapuan ldquoNatural fiber reinforcedpolymer composites in industrial applications feasibility of datepalm fibers for sustainable automotive industryrdquo Journal ofCleaner Production vol 66 pp 347ndash354 2014

[21] A K Mohanty M A Khan and G Hinrichsen ldquoSurfacemodification of jute and its influence on performance ofbiodegradable jute-fabricBiopol compositesrdquo Composites Sci-ence and Technology vol 60 no 7 pp 1115ndash1124 2000


[22] T Hanninen A Thygesen S Mehmood B Madsen and MHughes ldquoMechanical processing of bast fibres the occurrenceof damage and its effect on fibre structurerdquo Industrial Crops andProducts vol 39 no 1 pp 7ndash11 2012

[23] V K Thakur and M K Thakur ldquoProcessing and characteriza-tion of natural cellulose fibersthermoset polymer compositesrdquoCarbohydrate Polymers vol 109 pp 102ndash117 2014

[24] I Van de Weyenberg J Ivens A De Coster B Kino EBaetens and I Verpoest ldquoInfluence of processing and chemicaltreatment of flax fibres on their compositesrdquoComposites Scienceand Technology vol 63 no 9 pp 1241ndash1246 2003

[25] D Dai and M Fan ldquoWood fibres as reinforcements in naturalfibre composites structure properties processing and appli-cationsrdquo in Natural Fibre Composites Materials Processes andProperties chapter 1 pp 3ndash65 Woodhead Publishing 2014

[26] V S Srinivasan S R Boopathy D Sangeetha and B VRamnath ldquoEvaluation of mechanical and thermal properties ofbanana-flax based natural fibre compositerdquoMaterials amp Designvol 60 pp 620ndash627 2014

[27] J-C Benezet A Stanojlovic-Davidovic A Bergeret LFerry and A Crespy ldquoMechanical and physical properties ofexpanded starch reinforced by natural fibresrdquo Industrial Cropsand Products vol 37 no 1 pp 435ndash440 2012

[28] A R Kakroodi S Cheng M Sain and A Asiri ldquoMechanicalthermal and morphological properties of nanocompositesbased on polyvinyl alcohol and cellulose nanofiber from Aloevera rindrdquo Journal of Nanomaterials vol 2014 Article ID903498 7 pages 2014

[29] M S Sreekala M G Kumaran and S Thomas ldquoStress relax-ation behaviour in oil palm fibresrdquoMaterials Letters vol 50 no4 pp 263ndash273 2001

[30] B Ren T Mizue K Goda and J Noda ldquoEffects of fluctuationof fibre orientation on tensile properties of flax sliver-reinforcedgreen compositesrdquo Composite Structures vol 94 no 12 pp3457ndash3464 2012

[31] Y Pan and Z Zhong ldquoA micromechanical model for themechanical degradation of natural fiber reinforced compositesinduced by moisture absorptionrdquo Mechanics of Materials vol85 pp 7ndash15 2015

[32] E Jayamani S Hamdan M R Rahman and M K BBakri ldquoInvestigation of fiber surface treatment on mechanicalacoustical and thermal properties of betelnut fiber polyestercompositesrdquo Procedia Engineering vol 97 pp 545ndash554 2014

[33] L Boopathi P S Sampath and K Mylsamy ldquoInvestigation ofphysical chemical and mechanical properties of raw and alkalitreated Borassus fruit fiberrdquoComposites Part B Engineering vol43 no 8 pp 3044ndash3052 2012

[34] M Ramesh T S A Atreya U S Aswin H Eashwar andC Deepa ldquoProcessing and mechanical property evaluation ofbanana fiber reinforced polymer compositesrdquo Procedia Engi-neering vol 97 pp 563ndash572 2014

[35] N Venkateshwaran A Elaya Perumal and D Arunsun-daranayagam ldquoFiber surface treatment and its effect onmechanical and visco-elastic behaviour of bananaepoxy com-positerdquoMaterials amp Design vol 47 pp 151ndash159 2013

[36] S N Monteiro K G Satyanarayana A S Ferreira et alldquoSelection of high strength natural fibersrdquo Materia vol 15 no4 pp 488ndash505 2010

[37] H Ismail H D Rozman R M Jaffri and Z A Mohd IshakldquoOil palm wood flour reinforced epoxidized natural rubbercomposites the effect of filler content and sizerdquo EuropeanPolymer Journal vol 33 no 10ndash12 pp 1627ndash1632 1997

[38] M Jawaid and H P S Abdul Khalil ldquoCellulosicsynthetic fibrereinforced polymer hybrid composites a reviewrdquo CarbohydratePolymers vol 86 no 1 pp 1ndash18 2011

[39] MGeorge P GMussone Z Abboud andDC Bressler ldquoChar-acterization of chemically and enzymatically treated hempfibres using atomic forcemicroscopy and spectroscopyrdquoAppliedSurface Science vol 314 pp 1019ndash1025 2014

[40] P Wongsriraksa K Togashi A Nakai and H Hamada ldquoCon-tinuous natural fiber reinforced thermoplastic composites byfiber surface modificationrdquo Advances in Mechanical Engineer-ing vol 5 Article ID 685104 2013

[41] J Gassan and A K Bledzki ldquoPossibilities for improving themechanical properties of juteepoxy composites by alkali treat-ment of fibresrdquo Composites Science and Technology vol 59 no9 pp 1303ndash1309 1999

[42] M Z Rong M Q Zhang Y Liu G C Yang and H M ZengldquoThe effect of fiber treatment on the mechanical properties ofunidirectional sisal-reinforced epoxy compositesrdquo CompositesScience and Technology vol 61 no 10 pp 1437ndash1447 2001

[43] T P T Tran J-C Benezet and A Bergeret ldquoRice and Einkornwheat husks reinforced poly(lactic acid) (PLA) biocompositeseffects of alkaline and silane surface treatments of husksrdquoIndustrial Crops and Products vol 58 pp 111ndash124 2014

[44] S I Hossain M Hasan M N Hasan and A Hassan ldquoEffectof chemical treatment on physical mechanical and thermalproperties of ladies finger natural fiberrdquo Advances in MaterialsScience and Engineering vol 2013 Article ID 824274 6 pages2013

[45] A OrsquoDonnell M A Dweib and R P Wool ldquoNatural fibercomposites with plant oil-based resinrdquo Composites Science andTechnology vol 64 no 9 pp 1135ndash1145 2004

[46] H Luo G Xiong C Ma et al ldquoMechanical and thermo-mechanical behaviors of sizing-treated corn fiberpolylactidecompositesrdquo Polymer Testing vol 39 pp 45ndash52 2014

[47] H Ismail A Rusli and A A Rashid ldquoMaleated natural rubberas a coupling agent for paper sludge filled natural rubbercompositesrdquo Polymer Testing vol 24 no 7 pp 856ndash862 2005

[48] A Paul K Joseph and SThomas ldquoEffect of surface treatmentson the electrical properties of low-density polyethylene com-posites reinforced with short sisal fibersrdquo Composites Scienceand Technology vol 57 no 1 pp 67ndash79 1997

[49] F Corrales F Vilaseca M Llop J Girones J A Mendez and PMutje ldquoChemical modification of jute fibers for the productionof green-compositesrdquo Journal of Hazardous Materials vol 144no 3 pp 730ndash735 2007

[50] F G Torres and M L Cubillas ldquoStudy of the interfacialproperties of natural fibre reinforced polyethylenerdquo PolymerTesting vol 24 no 6 pp 694ndash698 2005

[51] A Hidayat and S Tachibana ldquoCharacterization of polylac-tic acid (PLA)kenaf composite degradation by immobilizedmycelia of Pleurotus ostreatusrdquo International Biodeterioration ampBiodegradation vol 71 pp 50ndash54 2012

[52] L He X Li W Li J Yuan and H Zhou ldquoA method for deter-mining reactive hydroxyl groups in natural fibers applicationto ramie fiber and its modificationrdquo Carbohydrate Research vol348 pp 95ndash98 2012

[53] K Xie H Liu and X Wang ldquoSurface modification of cellulosewith triazine derivative to improve printability with reactivedyesrdquo Carbohydrate Polymers vol 78 no 3 pp 538ndash542 2009

[54] N Cordeiroa M Ornelasa A Ashorib S Sheshmanic and HNorouzic ldquoInvestigation on the surface properties of chemically


modified natural fibers using inverse gas chromatographyrdquoCarbohydrate Polymers vol 87 no 4 pp 2367ndash2375 2012

[55] M Le Troedec D Sedan C Peyratout et al ldquoInfluence ofvarious chemical treatments on the composition and structureof hemp fibresrdquo Composites Part A Applied Science and Manu-facturing vol 39 no 3 pp 514ndash522 2008

[56] M J John B Francis K T Varughese and S Thomas ldquoEffectof chemical modification on properties of hybrid fiber biocom-positesrdquoComposites Part A Applied Science andManufacturingvol 39 no 2 pp 352ndash363 2008

[57] M Nasir A Gupta M D H Beg G K Chua and A KumarldquoFabrication of medium density fibreboard from enzymetreated rubber wood (Hevea brasiliensis) fibre and modifiedorganosolv ligninrdquo International Journal of Adhesion and Adhe-sives vol 44 pp 99ndash104 2013

[58] M Rokbi H Osmani A Imad and N Benseddiq ldquoEffectof chemical treatment on flexure properties of natural fiber-reinforced polyester compositerdquo Procedia Engineering vol 10pp 2092ndash2097 2011

[59] H L BosThepotential of flax fibres as reinforcement for compos-ite materials [PhD thesis] Technische Universiteit EindhovenEindhoven The Netherlands 2004

[60] B C Suddell ldquoIndustrial fibres recent and current develop-mentsrdquo in Proceedings of the Symposium on Natural Fibres vol20 pp 71ndash82 FAO CFC Rome Italy October 2008

[61] K Pickering Ed Properties and Performance of Natural-FibreComposites Woodhead Publishing Cambridge UK 2008

[62] A K Mohanty M Misra and L T Drzal Eds Natural FibersBiopolymers and Biocomposites Taylor amp Francis 2005

[63] T Sen and H N Reddy ldquoVarious industrial applications ofhemp kinaf flax and ramie natural fibresrdquo International Journalof Innovation Management and Technology vol 2 pp 192ndash1982011

[64] U S Bongarde and V D Shinde ldquoReview on natural fiberreinforcement polymer compositerdquo International Journal ofEngineering Science and Innovative Technology vol 3 no 2 pp431ndash436 2014

[65] L Mwaikambo ldquoReview of the history properties and applica-tion of plant fibresrdquo African Journal of Science and Technologyvol 7 no 2 p 121 2006

[66] F Bateni F Ahmad A S Yahya and M Azmi ldquoPerformanceof oil palm empty fruit bunch fibres coated with acrylonitrilebutadiene styrenerdquoConstruction and BuildingMaterials vol 25no 4 pp 1824ndash1829 2011

[67] M George P GMussone andD C Bressler ldquoSurface and ther-mal characterization of natural fibres treated with enzymesrdquoIndustrial Crops and Products vol 53 pp 365ndash373 2014

[68] K Joseph R D T Filho B James SThomas and L H de Car-valho ldquoA review on sisal fiber reinforced polymer compositesrdquoRevista Brasileira de Engenharia Agrıcola e Ambiental vol 3 no3 pp 367ndash379 1999

[69] C Alves PM C Ferrao A J Silva et al ldquoEcodesign of automo-tive components making use of natural jute fiber compositesrdquoJournal of Cleaner Production vol 18 no 4 pp 313ndash327 2010

[70] M Sain S H Park F Suhara and S Law ldquoFlame retardantand mechanical properties of natural fibre-PP compositescontaining magnesium hydroxiderdquo Polymer Degradation andStability vol 83 no 2 pp 363ndash367 2004

[71] A Alhuthali I M Low and C Dong ldquoCharacterisation of thewater absorption mechanical and thermal properties of recy-cled cellulose fibre reinforced vinyl-ester eco-nanocompositesrdquo

Composites Part B Engineering vol 43 no 7 pp 2772ndash27812012

[72] Z N Azwa B F Yousif A C Manalo and W Karunasena ldquoAreview on the degradability of polymeric composites based onnatural fibresrdquoMaterials amp Design vol 47 pp 424ndash442 2013

[73] E Gallo B Schartel D Acierno F Cimino and P RussoldquoTailoring the flame retardant and mechanical performancesof natural fiber-reinforced biopolymer by multi-componentlaminaterdquoComposites Part B Engineering vol 44 no 1 pp 112ndash119 2013

[74] S Fatima and A R Mohanty ldquoAcoustical and fire-retardantproperties of jute composite materialsrdquo Applied Acoustics vol72 no 2-3 pp 108ndash114 2011

[75] N P G Suardana M S Ku and J K Lim ldquoEffects ofdiammonium phosphate on the flammability and mechanicalproperties of bio-compositesrdquo Materials amp Design vol 32 no4 pp 1990ndash1999 2011

[76] B Schartel U Braun U Knoll et al ldquoMechanical thermal andfire behavior of bisphenol a polycarbonatemultiwall carbonnanotube nanocompositesrdquo Polymer Engineering amp Science vol48 no 1 pp 149ndash158 2008

[77] J Zhan L Song S Nie and Y Hu ldquoCombustion properties andthermal degradation behavior of polylactide with an effectiveintumescent flame retardantrdquo Polymer Degradation and Stabil-ity vol 94 no 3 pp 291ndash296 2009

[78] TDHapuarachchi andT Peijs ldquoMultiwalled carbon nanotubesand sepiolite nanoclays as flame retardants for polylactide andits natural fibre reinforced compositesrdquo Composites Part AApplied Science and Manufacturing vol 41 no 8 pp 954ndash9632010

[79] G Savage ldquoDevelopment of penetration resistance in thesurvival cell of a Formula 1 racing carrdquo Engineering FailureAnalysis vol 17 no 1 pp 116ndash127 2010

[80] J Meredith R Ebsworth S R Coles B M Wood and KKirwan ldquoNatural fibre composite energy absorption structuresrdquoComposites Science and Technology vol 72 no 2 pp 211ndash2172012

[81] P Wambua B Vangrimde S Lomov and I Verpoest ldquoTheresponse of natural fibre composites to ballistic impact byfragment simulating projectilesrdquo Composite Structures vol 77no 2 pp 232ndash240 2007

[82] P K Bajpai I Singh and J Madaan ldquoTribological behavior ofnatural fiber reinforced PLA compositesrdquoWear vol 297 no 1-2pp 829ndash840 2013

[83] N S M El-Tayeb B F Yousif and T C Yap ldquoTribologicalstudies of polyester reinforced with CSM 450-R-glass fibersliding against smooth stainless steel counterfacerdquo Wear vol261 no 3-4 pp 443ndash452 2006

[84] C W Chin and B F Yousif ldquoPotential of kenaf fibres asreinforcement for tribological applicationsrdquo Wear vol 267 no9-10 pp 1550ndash1557 2009

[85] U Nirmal B F Yousif D Rilling and P V Brevern ldquoEffect ofbetelnut fibres treatment and contact conditions on adhesivewear and frictional performance of polyester compositesrdquoWearvol 268 no 11-12 pp 1354ndash1370 2010

[86] X Xin C G Xu and L F Qing ldquoFriction properties of sisalfibre reinforced resin brake compositesrdquoWear vol 262 no 5-6pp 736ndash741 2007

[87] N S M El-Tayeb ldquoA study on the potential of sugarcanefiberspolyester composite for tribological applicationsrdquo Wearvol 265 no 1-2 pp 223ndash235 2008


[88] S A R Hashmi U K Dwivedi and N Chand ldquoGraphitemodified cotton fibre reinforced polyester composites undersliding wear conditionsrdquoWear vol 262 no 11-12 pp 1426ndash14322007

[89] M M Davoodi S M Sapuan D Ahmad A Aidy A Khalinaand M Jonoobi ldquoConcept selection of car bumper beam withdeveloped hybrid bio-composite materialrdquoMaterials amp Designvol 32 no 10 pp 4857ndash4865 2011

[90] N Banthia and R Gupta ldquoInfluence of polypropylene fibergeometry on plastic shrinkage cracking in concreterdquo Cementand Concrete Research vol 36 no 7 pp 1263ndash1267 2006

[91] M S Sreekala and S Thomas ldquoEffect of fibre surface mod-ification on water-sorption characteristics of oil palm fibresrdquoComposites Science and Technology vol 63 no 6 pp 861ndash8692003

[92] M H Ab Ghani and S Ahmad ldquoThe comparison of waterabsorption analysis between counterrotating and corotatingtwin-screw extruders with different antioxidants content inwood plastic compositesrdquo Advances in Materials Science andEngineering vol 2011 Article ID 406284 4 pages 2011

[93] M Mariatti M Jannah A A Bakar and H P S A KhalilldquoProperties of banana and pandanus woven fabric reinforcedunsaturated polyester compositesrdquo Journal of Composite Mate-rials vol 42 no 9 pp 931ndash941 2008

[94] S N Monteiro V Calado R J S Rodriguez and F MMargem ldquoThermogravimetric behavior of natural fibers rein-forced polymer compositesmdashan overviewrdquo Materials Scienceand Engineering A vol 557 pp 17ndash28 2012

[95] O Hassan T P Ling M Y Maskat et al ldquoOptimization ofpretreatments for the hydrolysis of oil palm empty fruit bunchfiber (EFBF) using enzyme mixturesrdquo Biomass and Bioenergyvol 56 pp 137ndash146 2013

[96] G George E T Jose D Akesson M Skrifvars E R Nagarajanand K Joseph ldquoViscoelastic behaviour of novel commingledbiocomposites based on polypropylenejute yarnsrdquo CompositesPart A Applied Science and Manufacturing vol 43 no 6 pp893ndash902 2012

[97] V Fiore T Scalici and A Valenza ldquoCharacterization of a newnatural fiber from Arundo donax L as potential reinforcementof polymer compositesrdquo Carbohydrate Polymers vol 106 no 1pp 77ndash83 2014

[98] S Shinoj R Visvanathan and S Panigrahi ldquoTowards industrialutilization of oil palm fibre physical and dielectric charac-terization of linear low density polyethylene composites andcomparison with other fibre sourcesrdquo Biosystems Engineeringvol 106 no 4 pp 378ndash388 2010

[99] E Sassoni S Manzi A Motori M Montecchi and M CantildquoNovel sustainable hemp-based composites for application inthe building industry physical thermal and mechanical char-acterizationrdquo Energy and Buildings vol 77 pp 219ndash226 2014

[100] J Holbery and D Houston ldquoNatural-fiber-reinforced polymercomposites in automotive applicationsrdquo JOM vol 58 no 11 pp80ndash86 2006

[101] S H Shuit K T Tan K T Lee and A H Kamaruddin ldquoOilpalm biomass as a sustainable energy source a Malaysian casestudyrdquo Energy vol 34 no 9 pp 1225ndash1235 2009

[102] A R Kakroodi Y Kazemi and D Rodrigue ldquoMechanicalrheological morphological and water absorption properties ofmaleated polyethylenehemp composites effect of ground tirerubber additionrdquo Composites Part B Engineering vol 51 pp337ndash344 2013

[103] S Kalia and B S KaithCellulose Fibers Bio- and Nano-PolymerComposites Springer 2011

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


Table 1 Natural fibers in the world and their world production [4]

Fiber source World production (103 ton)Bamboo 30000Sugar cane bagasse 75000Jute 2300Kenaf 970Flax 830Grass 700Sisal 375Hemp 214Coir 100Ramie 100Abaca 70

damage to processing equipment good relative mechani-cal properties such as tensile modulus and flexural mod-ulus improved surface finish of molded parts compositerenewable resources being abundant [5] flexibility duringprocessing biodegradability and minimal health hazardsNFPCs with a high specific stiffness and strength can beproduced by adding the tough and light-weight natural fiberinto polymer (thermoplastic and thermoset) [6] On theother hand natural fibers are not free from problems andthey have notable deficits in properties The natural fibersstructure consists of (cellulose hemicelluloses lignin pectinand waxy substances) and permits moisture absorption fromthe surroundings which causes weak bindings between thefiber and polymer Furthermore the couplings betweennatural fiber and polymer are considered a challenge becausethe chemical structures of both fibers and matrix are vari-ous These reasons for ineffectual stress transfer during theinterface of the produced composites Accordingly naturalfiber modifications using specific treatments are certainlynecessary These modifications are generally centered on theutilization of reagent functional groups which have abilityfor responding of the fiber structures and changing theircomposition As a result fiber modifications cause reductionof moisture absorption of the natural fibers which lead to anexcellent enhancement incompatibility between the fiber andpolymer matrix [7]

The wide applications of NFPCs are growing rapidlyin numerous engineering fields The different kinds of nat-ural fibers reinforced polymer composite have received agreat importance in different automotive applications bymany automotive companies such as German auto compa-nies (BMW Audi Group Ford Opel Volkswagen Daim-ler Chrysler and Mercedes) Proton company (Malaysiannational carmaker) and Cambridge industry (an auto indus-try in USA) Beside the auto industry the applications ofnatural fiber composites have also been found in buildingand construction industry sports aerospace and others forexample panels window frame decking and bicycle frame[8]

In a review of chemical treatments of natural fibers Kabirand coworkers [9] concurred that treatment is an importantfactor that has to be considered when processing natural

fibers They observed that fibers loose hydroxyl groupsdue to different chemical treatments thereby reducing thehydrophilic behavior of the fibers and causing enhancementin mechanical strength as well as dimensional stability ofnatural fiber reinforced polymer composites Their generalconclusion was that chemical treatment of natural fibersresults in a remarkable improvement of the NFPCs

2 Natural Fiber ReinforcedComposites (NFPCs)

Natural fiber polymer composites (NFPC) are a compositematerial consisting of a polymer matrix embedded withhigh-strength natural fibers like jute oil palm sisal kenafand flax [10] Usually polymers can be categorized intotwo categories thermoplastics and thermosetsThe structureof thermoplastic matrix materials consists of one or twodimensional moleculars so these polymers have a tendencyto make softer at an raised heat range and roll backtheir properties throughout cooling On the other handthermosets polymer can be defined as highly cross-linkedpolymers which cured using only heat or using heat andpressure andor light irradiation This structure gives tothermoset polymer good properties such as high flexibilityfor tailoring desired ultimate properties great strength andmodulus [3 4] Thermoplastics widely used for biofibers arepolyethylene [11] polypropylene (PP) [12] and poly vinylychloride (PVC) hereas phenolic polyester and epoxy resinsare mostly utilized thermosetting matrices [10] Differentfactors can affect the characteristics and performance ofNFPCsThehydrophilic nature of the natural fiber [5] and thefiber loading also have impacts on the composite properties[13] Usually high fiber loading is needed to attain goodproperties of NFPCs [14] Generally notice that the rise infiber content causes improving in the tensile properties ofthe composites [8] Another vital factor that considerablyimpacts the properties and surface characteristics of thecomposites is the process parameters utilized For that reasonappropriate process techniques and parameters should berigorously chosen in order to get the best characteristicsof producing composite [10] The chemical composition ofnatural fibers also has a big effect on the characteristics ofthe composite represented by the percentage of cellulosehemicellulose lignin and waxes Table 2 shows the chemicalcomposition of some common natural fibers [4]

Many researchers [8 11 15ndash17] have examined andresearched the suitability competitiveness and capabilitiesof natural fibers embedded in polymeric matrices Theresearchers [4 18 19] concentrated on the effect of the fibersurface modifications as well as manufacturing processes inimproving fiberpolymer compatibility On the other handsome researchers studied and compared between differentnatural fiber composites and their stability in various applica-tions [20] Al-Oqla and Sapuan [20] investigated the proper-ties of juteplastic composites such as crystallinity fibermod-ification thermal stability weathering resistance durabilityin addition to their suitability to the automotive industrythroughout ecodesign components while Mohanty et al [21]studied the effects of jute fiber on the mechanical properties










more






PLA

PLA

Lju

te

PLA

flax PP

PPk

enaf

PPh

emp

PPc

otto

n

Epox

y

Epox

yju

te

Poly

este

r

Poly

este

rju

te



0

20

40

60

80

100

120

140

160

Mod

ulus

(GPa

)

0

20

40

60

80

100

120

140

Stre

ngth

(MPa

)












2 and










(a) Heating







3)] and




2O3+ 3H2O Δ119867 = 20 calg (1)


2O Δ119867 = 328 calg (2)

























4) maleic anhy-


30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

1Hz

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

07

08

09

tan 120575



4andMAPP





30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575




030

045

060

075

090

2 4310

log time (s)

120590t1205900





2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)



















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials












more






PLA

PLA

Lju

te

PLA

flax PP

PPk

enaf

PPh

emp

PPc

otto

n

Epox

y

Epox

yju

te

Poly

este

r

Poly

este

rju

te



0

20

40

60

80

100

120

140

160

Mod

ulus

(GPa

)

0

20

40

60

80

100

120

140

Stre

ngth

(MPa

)












2 and










(a) Heating







3)] and




2O3+ 3H2O Δ119867 = 20 calg (1)


2O Δ119867 = 328 calg (2)

























4) maleic anhy-


30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

1Hz

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

07

08

09

tan 120575



4andMAPP





30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575




030

045

060

075

090

2 4310

log time (s)

120590t1205900





2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)



















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






PLA

PLA

Lju

te

PLA

flax PP

PPk

enaf

PPh

emp

PPc

otto

n

Epox

y

Epox

yju

te

Poly

este

r

Poly

este

rju

te



0

20

40

60

80

100

120

140

160

Mod

ulus

(GPa

)

0

20

40

60

80

100

120

140

Stre

ngth

(MPa

)












2 and










(a) Heating







3)] and




2O3+ 3H2O Δ119867 = 20 calg (1)


2O Δ119867 = 328 calg (2)

























4) maleic anhy-


30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

1Hz

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

07

08

09

tan 120575



4andMAPP





30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575




030

045

060

075

090

2 4310

log time (s)

120590t1205900





2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)



















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






2 and










(a) Heating







3)] and




2O3+ 3H2O Δ119867 = 20 calg (1)


2O Δ119867 = 328 calg (2)

























4) maleic anhy-


30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

1Hz

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

07

08

09

tan 120575



4andMAPP





30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575




030

045

060

075

090

2 4310

log time (s)

120590t1205900





2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)



















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials









3)] and




2O3+ 3H2O Δ119867 = 20 calg (1)


2O Δ119867 = 328 calg (2)

























4) maleic anhy-


30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

1Hz

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

07

08

09

tan 120575



4andMAPP





30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575




030

045

060

075

090

2 4310

log time (s)

120590t1205900





2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)



















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




















4) maleic anhy-


30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

1Hz

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

07

08

09

tan 120575



4andMAPP





30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575




030

045

060

075

090

2 4310

log time (s)

120590t1205900





2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)



















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




30 40 50 60 70 80 90 100 110 120 130 140

Temperature (∘C)

Untreated1 NaOH

5 NaOH

0

01

02

03

04

05

06

0710Hz

tan 120575




030

045

060

075

090

2 4310

log time (s)

120590t1205900





2 4310

log time (s)

100

200

300

400

500

600

700

Er(t)

(MPa

)



















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials















































5 Conclusions




References





















































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials

































































































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



review article a review on natural fiber reinforced...

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