RESULTS two polymorphs state, a monoclinic structure

RESULTSAND DISCUSSION3.1Xrd Analysis :An X-raydiffractogram of three portions of jute is shown in Fig.

2. and Table 1.  The diffraction patterns of the root portion jutedisplayed three mainpeaks at 16.30?, 22.24?, and 34.59? of thecellulose-I, which are due to the  , 0 0 2, and 0 4 0 respectively. Themiddle portion jute had three main peaks at 16.39?, 22.

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33?, and 34.59?of the cellulose-I which were assigned to  , 0 0 2, and 0 4 0 respectively. Similarly the diffraction pattern of tip portionjute shows the crystalline structure of cellulose I peaks at 16.57?,22.15? and 34.68? and are assigned to  , 0 0 2, and 0 4 0 respectively. Cellulose I is thermodynamically metastable and canbe changed to either cellulose II or III. Crystalline Cellulose I exist in twopolymorphs state, a monoclinic structure I? and a triclinic structure I?, whichcoexist in various extent depending on the cellulose structure.

The triclinicI? component is a rare component, whereas I? is the principal portion. Themetastable I? polymorph can be transformed into I? by hydrothermal treatmentsin alkaline solution (Poletto et al., 2013).The unit cell dimensions are observed from table that the I? unit cell the cellparameters are a = 8.05 Å, b = 10.36 Å, c = 8.01 Å and ?= 94.92?? for root portion, a = 7.

81 Å, b = 10.36Å, c = 7.96 Å and ? = 93.57? for middle portion and a= 7.80 Å, b = 10.

33 Å, c = 8.04 Å and ? = 95.20?for tip portion jute. It is reported in the literature that for I? cellulosesamples have unit cell dimensions are a = 7.784 Å , b = 8.

201 Å , c = 10.380 Å, and ? = 96.55?, the diffraction patterns patterns for Ib samples with preferred orientation along the c-axis (French 2014).  The crystalsize of three portions of jute is calculated by using Scherrerequation, the crystal size of root, middle and tip portion jute samples are 3.35 nm, 3.26 nm and 3.18 nm and 4.

93 nm respectively. The crystallite size of the jute fibers; the valuesare in the order: root > middle > tip indicating higher rigidity ofcellulose fibers and decreasing crystallite surface corresponding to theamorphous phase.  However, it isimportant to mention that the crystallite size as calculated in mostliteratures cannot provide much information regarding mechanical properties ofcellulosic fibres (Júnior 2014; Keten2010). Further,the crystallinity index of root, middle and tip portion jute are found to be 62.4,64.6 and 65.1 respectively.

The microfibrillerangle of root, middleand tip portion jute are observed to be 10.8?, 8.0? and 7.2?respectively. Themicrofibriller angle is found to be decreased and crystalline index is increased from root to tip portion of jutefibre.

  Crystalinity index andmicrofibriller angle play considerable role on mechanical properties ofcellulosic fibre. The tensile strength and modulus of jute fibres have beenproved to be dependent on crystalinity index and microfibriller angle i.e the orientation of the crystalline cellulose. Tensilestrength and modulus of jute fibre are inversely related to microfibrillerangle and increases with increase in crystallinity index. Cellulosic fibre selection for reinforcement purposethe crystalinity index and microfibriller angle of fibre plays importantfunction on mechanical properties of composite (Mwaikambo, 2009; Leonard,2009).

 3.2FTIR Analysis of Three Portion of Jute:The chemical nature of the jutefibres was analyzed using FTIR and depicted in Fig.3. FTIR spectrum of the juteshows chemical groups presence in the three basic constituent componentcellulose, hemicellulose and lignin (Fan et al.2012). A broad absorption band in the region 3600–3200 cm-1for three portions of jute is observed associated with the –OH stretching ofthe hydroxyl group of cellulose and intra-hydrogen bond stretching of theabsorbed water. The peaks at 2915, 2916 and 2918 cm-1 areresponsible for the -CH stretching vibration from CH and CH2 incellulose and hemicellulose components and the peaks at 1735, 1733 and 1732 cm-1  assigned to the carbonyl C=O stretching ofcarboxylic acid in lignin or ester group in hemicelluloses.

A little peak at1507 and 1510 cm-1 are associated with the C=C stretching ofaromatic ring of the lignin. The absorbance at 1424, 1421 and 1422 cm-1is due to the presence of CH2 symmetric bending present in celluloseand lignin. The absorbance peaks at 1368, 1367 and 1366 cm-1correspond to the C–H stretching vibration presence in cellulose andhemicellulose component, respectively (Bodirlau& Teaca 2009). The peak at 1157, 1156 and 1155 cm-1 isdue to the anti-symmetrical deformation of the C-O-C band. The strong peak at1030, 1021 and 1020  cm-1 is attributedto the CO and O-H stretching vibration which associated to polysaccharide incellulose (De Rosa et al.

2010 ).   3.3Fibre fineness and diameter: Itwas found that the fibre fineness of root, middle and tip portion were 2.74 tex, 2.00 tex and 2.00 tex respectively. The root portion fibres are coarser thanmiddle and tip portion fibres of jute reed. It was observed that the averagevalue of fibre diameter of root, middle and tip portion were 61 µm , 59.

7 µmand 52.6  µm respectively.  The fibre diameter follows the same trendlike fibre fineness. The frequency distributions of fibre diameters are shownin Fig.4. The fibre diameter is an important parameter relates to mechanicalproperties of composite. Fibre surface area related with interlaminar shearstrength of composite and the wetting behaviour with matrix material (Steinmann & Saelhoff 2016).

The highsurface area of fibers is desirable property to get good physical adhesion withmatrix material which can be achieved by their small diameter compared to theirlength. 3.4Jute Fibre Strength Test: Fibrebundle test results show that bundle strength of root, middle and tip portionwere 21 g/tex, 18.8 g/tex  and 16 g/texrespectively.

It was found that bundle strength of jute fibre decreases alongthe lengthwise from root to tip portion. The single fibre tensile strengthproperties of three portions of jute reed are shown in Fig.5. The single fibretensile strength of root, middle and tip portions is 534 MPa, 406 MPa and 357MP respectively.

The elongation at break of root, middle and tip portions are 2.43%,1.98% and 1.63% respectively. The tensile modulus of root, middle and tipportions are shown to be 29.5GPa, 30.2GPa and 40.5GPa respectively.

It isobserved that the tensile strength is gradually decreased from root to tipportions, but tensile modulus is increased from root to tip portion. Fibers arethe main load bearing component of a fibre based composite material. Accordingto rule of mixture for perfectly bonded composite the tensile strength andmodulus of fibre is directly proportional to tensile strength and modulus ofcomposite. Fig.5. Tensileproperties of three portion jute  3.5 Tensile Properties of JuteComposites: Thetensile properties of a fibre reinforced composite are mainly influenced bytensile properties of fibre, fibre/matrix interfacial bonding, fibre content,aspect ratio of the fibre, orientation of the fibres and the dispersion gradeof the fibre into the matrix (Thakur, 2014; Serrano et al.

, 2014). Tensile andflexural properties of the resin and composite samples are shown in the Fig.6.It is observed that the matrix material polyester resin had a tensile strengthof 26.8 MPa and modulus of 0.96 GPa. Itwas observed that the composites made from root portion, middle portion and tipportion had tensile strength of 135.6 MPa,107.

8 MPa and 94.2 MPa respectively. The tensile modulus of composites made from rootportion, middle portion and tip portion had7.42 GPa, 7.

68 GPa and 8.74 GPa respectively. The tensile strength and modulusof a composite is mainly dependent on the strength and modulus of reinforcingmaterials and the bonding strength between fibre and matrix.  The fibre is the main load bearing componentfor perfectly bonded composite so effects of fibre tensile propertiesvariations are directly affect the tensile properties of composite.    3.6 Flexural Properties of JuteComposites: Fig.6 shows the flexural propertiesof three types of jute composites and polyester resin, subjected to flexuralload.

Flexural strength and modulus of a composite is dependent on the fibrestrength and extreme layer of reinforcement plays a vital role. The crackalways starts on the tension side of the composite sample and slowly propagatesin an upward direction. In general, the flexural modulus is very sensitive tothe matrix properties and fibre-matrix interfacial bonding. It has beenobserved that, the polyester resin had flexural strength and modulus of 32.7 MPaand 3.74 GPa. It was observed that the composites made from root portion, middleportion and tip portion had flexural strength of 151.

3 MPa, 142 MPa and 112MParespectively. The flexural modulus of composites madefrom root portion, middle portion and tip portion had 10.13 GPa, 11.21 GPa and 11.

88GParespectively. Composite made from root portion hadhigher flexural strength and lower flexural modulus than middle and tip portionbased composites due to higher tensile strength and lower tensile modulus ofroot portion jute fibre. Middle portion based composite had higher flexuralstrength and lower modulus than tip portion based composite.

  4. Conclusion: It can be concludedthatJute fibre diameter, fineness,tensile strength and bundlestrength is decreased along the length from root to tip portion of jute reedbut the tensile modulus is increased from root to tip. Jute fibre strength variation has a greateffect on mechanical properties of jute composites. The compositeprepared from root portion jute had higher tensile and flexural strength thanmiddle and tip portion based composites. The middle portion based composite hadhigher tensile and flexural strength than tip portion based composites. Thetensile and flexural modulus is observed to be increased from root to tipportions based composite. Itcan be recommended that root portion jute is the best reinforcing material considering tensile and flexuralproperties compare to the middle and tip portion of raw jute reed.

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