Faculty Publications

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Author: search.filters.author.Anandhan, S.Subject: search.filters.subject.Tensile strength

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    Extruded poly(ethylene-co-octene)/fly ash composites - Value added products from an environmental pollutant
    (Kluwer Academic Publishers, 2012) Anandhan, S.; Sundar, S.M.; Senthil, T.; Mahendran, A.R.; Shibulal, G.S.
    Fly ash (FA) is a by-product generated during combustion of coal and has caused serious environmental concerns. In an effort to utilize FA beneficially, we developed composites from an ethylene-octene random copolymer (EOC) and unmodified as well as surfacemodified class-F fly ash (MFA) by twin screw extrusion. Addition of 20 wt% of MFA to EOC improves its tensile strength by 150%; also, MFA improves stress at 100% and 300% strains (M100 and M300) of EOC. Thermal stability of EOC matrix is appreciably improved by the addition of either FA or MFA, while the melting behavior is not appreciably influenced by either. Fractography study reveals an improved adhesion between the EOC and MFA particles up to a filler loading of 20%, beyond which the adhesion between EOC and MFA is weakened causing a reduction in mechanical properties. The 'flammable' nature of EOC changes to 'self extinguishing' on addition of even 10 wt% of FA or MFA, as found out from LOI study. © Springer Science+Business Media B.V. 2012.
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    Mechanical and sliding wear properties of multi-layered laminates from glass fabric/graphite/epoxy composites
    (Elsevier Ltd, 2013) Shivamurty, B.; Bhat, K.; Anandhan, S.
    Multi-layered laminates of bi-directionally woven E-glass fabric/epoxy with different loading of graphite particles were made by hand layup followed by compression molding. Tensile and flexural behaviors, impact strength, hardness and density of these laminates were determined. Wear behaviors of these composites were investigated by a pin-on-disc wear test apparatus. Specific wear rates of these composites strongly depend on their filler content and applied normal loads. The hybrid composite containing 3 wt% of graphite exhibits the optimum mechanical and wear performances. A further increase in the graphite content increases the specific wear rate and deteriorates the mechanical behavior. The lowest (? e)-1 factor (the reciprocal of the product of tensile strength and elongation at break) signifies the lowest specific wear rate. The results of the morphology study of the wear test specimens support the results of the wear test. © 2012 Elsevier Ltd.
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    Use of nano-ATH as a multi-functional additive for poly(ethylene-co-vinyl acetate-co-carbon monoxide)
    (Springer Verlag service@springer.de, 2014) George, G.; Mahendran, A.; Anandhan, S.
    Flame retardant aluminum hydroxide (ATH) nanoparticles of size ?10-20 nm were dispersed in ethylene-vinyl acetate-carbon monoxide terpolymer (EVACO) via solution casting. The effect of filler loading on the crystallizability, thermal, mechanical, flammability, optical and electrical properties of EVACO was evaluated. At 1 % filler loading nano-ATH particles exhibited very good dispersibility in the EVACO matrix and the % crystallinity of EVACO is the highest at this filler loading. The changes in crystallinity were studied by X-ray diffractometry and differential scanning calorimetry. The highest tensile strength was observed for the composite with 1 % nano-ATH loading, which has the best filler dispersion, and the decay in the tensile properties at higher filler loading is due to agglomerations of ATH nanoparticles and polymer-filler interface debonding. The UV absorption of these composites is augmented irrespective of the nano-ATH loading and ATH emerges as a good absorber of UV light. The DC electrical conductivity study of the composites proves that the addition nano-ATH is an efficient way to improve the dielectric properties of EVACO. The presence of nano-ATH improves the flame retardance of these composites. © 2014 Springer-Verlag Berlin Heidelberg.
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    Influence of organically modified clay mineral on domain structure and properties of segmented thermoplastic polyurethane elastomer
    (2014) Anandhan, S.; Lee, H.S.
    Segmented polyether-urethane/organically modified montmorillonite (O-MMT) nanocomposites were synthesized with poly(tetramethylene glycol) (PTMG), 4,4?-diphenylmethane diisocyanate (MDI), butane diol (BD), and a commercially available clay Cloisite-30B® (O-MMT). The state of dispersion of the clay crystals in the thermoplastic polyurethane elastomer (TPU) matrix was studied by X-ray diffraction and transmission electron microscopy (TEM). The phase-separated morphology of the TPU was revealed by high-resolution TEM (HRTEM) and atomic force microscopy (AFM). O-MMT caused a marginal increase in the glass transition temperature of the soft segments of the TPU and this increase is proportional to the amount of O-MMT in the nanocomposites. Differential scanning calorimetry (DSC) was employed to study the effect of O-MMT on the extent of phase separation in the TPU in these nanocomposites. Thermogravimetric analysis (TGA) results indicate a substantial improvement in the thermal stability of TPU by the addition of O-MMT. Tensile strength and elastic modulus are dramatically decreased by the incorporation of O-MMT into TPU, which is due to the hindrance of the phase-separation process by the exfoliated clay-layered crystals. © The Author(s) 2012 Reprints and permissions:sagepub.co.uk/journalsPermissions.nav.
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    Thermodynamic miscibility and thermal and mechanical properties of poly(ethylene-co-vinyl acetate-co-carbon monoxide)/poly(vinyl chloride) blends
    (John Wiley and Sons Inc, 2015) SelvaKumar, M.; Mahendran, A.; Bhagabati, P.; Anandhan, S.
    This paper reports the miscibility and thermal and mechanical properties of solution cast binary blends of poly(ethylene-co-vinyl acetate-co-carbon monoxide) (EVACO) and poly(vinyl chloride) (PVC). The composition of these blends was varied from 10:90 to 90:10 of PVC/EVACO (w/w %). Fourier transform infrared spectroscopy revealed an extensive intermolecular attraction between the blend components, which accounts for their mutual solubility. The differential scanning calorimetry study revealed that the blend components are miscible with each other in all proportions as they exhibited a single glass transition temperature. Tensile strength, moduli, and thermal stabilities of these blends significantly improved with increasing proportion of PVC. © 2014 Wiley Periodicals, Inc.
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    Sliding wear and mechanical properties of alumina/glass fabric/epoxy composites
    (Huthig GmbH, 2015) Shivamurty, B.; Anandhan, S.; Bhat, K.U.
    In this study, laminates of neat glass fabric/ epoxy composite (GEC) and three levels of Al2O3 filled glass fabric/epoxy composites, designated as 3AGEC, 6AGEC and 9AGEC (micro particulates of Al2O3 - by 3, 6 and 9 wt. % of resin respectively) were prepared using hand lay-up method. 3AGEC exhibits higher tensile strength, flexural strength and flexural modulus besides improved hardness compared to GEC, 6AGEC and 9AGEC. 3AGEC exhibits the lowest specific wear rate compared to GEC, 6AGEC and 9AGEC at all the three loads (i.e., 15, 30 and 45 N) and at a constant sliding velocity of 3.5 m· s-1 for a sliding distance of 1.5 km. It was found that beyond filler content of 3 wt. % is deteriorates the mechanical and sliding wear properties of the composites due to agglomeration of the filler. Also, it was found that lowest factor signifies lowest specific wear rate in both neat and all the Al2O3 filled composites.
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    Structure-property relationship of halloysite nanotubes/ethylene-vinyl acetate-carbon monoxide terpolymer nanocomposites
    (SAGE Publications Ltd info@sagepub.co.uk, 2017) George, G.; SelvaKumar, M.; Mahendran, A.; Anandhan, S.
    Poly(ethylene-co-vinyl acetate-co-carbon monoxide) (EVACO)/halloysite nanotube (HNT) nanocomposite films were solution cast. Dispersion of HNTs in the matrix was analyzed by elemental mapping and the role of HNTs on crystallizability, flammability and thermal, mechanical, and electrical properties of the polymer was evaluated. The nature of interaction between the EVACO matrix and HNTs was studied using Fourier transform infrared spectroscopy. The highest tensile strength was observed for the composite with 1% filler loading, whereas the highest crystallinity was observed for that with 3% filler loading. The decay in the tensile properties at higher filler loading was due to agglomeration of HNTs and debonding of polymer-filler interface. The electrical volume resistivity of the composites decreased with HNT loading because of the ionic charge transfer. The direct current electrical resistivity study of the composites proves that the addition of HNT can improve the antistatic properties of the polymer. © The Author(s) 2015.
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    Chitosan composites reinforced with nanostructured waste fly ash
    (Springer Japan, 2017) Patil, A.G.; Poornachandra, S.; Gumageri, R.; Rajkumar, K.; Anandhan, S.
    This paper outlines the preparation and characterization of chitosan (CS) composites reinforced with mechano-chemically activated fly ash (MCA-FA). A series of composite films was prepared by solution casting method with varying filler content. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses showed good compatibility between the CS matrix and MCA-FA. The surface roughness and irregularity in shape of MCA-FA resulted in its efficient mechanical interlocking with the polymer matrix. This, in turn enhanced the mechanical properties of these composites. All the composite films exhibited a higher tensile strength and a lower percentage of elongation-at-break compared with the pure CS film. The highest tensile strength was observed for the composite films with 1 wt% of filler loading and the reduction in the tensile properties at higher filler loading was due to agglomeration of filler and polymer–filler interface debonding. The tensile strength data were analyzed using Nielsen and Pukanzsky models to understand the interface formation and polymer–filler interactions. Thermal properties showed a marginal improvement due to the incorporation of MCA-FA. Overall, this study indicates that MCA-FA could be used as value added filler in polymer matrix composites. © 2016, Springer Japan.
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    Synergism of graphitic-carbon nitride and electrospinning on the physico-chemical characteristics and piezoelectric properties of flexible poly(vinylidene fluoride) based nanogenerator
    (Springer Netherlands rbk@louisiana.edu, 2019) Khalifa, M.; Mahendran, A.; Anandhan, S.
    Herein, we investigated the piezoelectric performance of electrospun poly(vinylidene fluoride)/graphitic carbon nitride (PVDF/g-C 3 N 4 ) nanocomposite fibers (PGN-X). Addition of g-C 3 N 4 nanosheets improved the spinnability of nanofibers and augmented the ?-phase content of PVDF. The synthesized PGN non-woven mats were flexible and easily deformable without disrupting the continuity of fibers. Upon the addition of g-C 3 N 4 , tensile strength and thermal stability of nanocomposite fibers improved significantly. A maximum voltage output of ~7.5 V was generated for PGN nanogenerator which is ~8 times more than that of PVDF nanogenerator. Also, the PGN-X nanogenerator generated current output of 0.23 ?A and a power density of 0.22 ?W/cm ?2 . Improved physico-chemical characteristics and piezoelectric performance of PGN nanogeneratoris promising and makes it suitable for portable electronic and wearable devices. © 2019, The Polymer Society, Taipei.
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    PVDF/halloysite nanocomposite-based non-wovens as gel polymer electrolyte for high safety lithium ion battery
    (John Wiley and Sons Inc. cs-journals@wiley.com, 2019) Khalifa, M.; Janakiraman, S.; Ghosh, S.; Adyam, A.; Anandhan, S.
    Gel polymer electrolyte (GPE) based on electrospun poly(vinylidene fluoride) (PVDF)/halloysite nanotube (HNT) nanocomposite non-wovens was synthesized and its suitability as a separator in lithium-ion battery (LIB) was explored. In this study, HNT played a key role in reducing the average diameter of the electrospun fibers and uplifted the porosity of the non-wovens thereby improving their electrolyte uptake. Due to a reduction in crystallinity and increased % porosity of the PVDF/HNT non-wovens, the ionic conductivity (1.77 mScm?1) and ionic transport across the separator were improved. Moreover, this GPE separator exhibited high tensile and puncture strength with negligible thermal shrinkage and a higher melting temperature compared with a commercially available separator, which is vital from the safety perspective. The cycling performance of Li/GPE/LiCoO2 cell was evaluated and it exhibited a high capacity of 138.01 mAhg?1 with 97% coulombic efficiency for the initial cycle. The cell was stable and retained its high performance with little loss in capacity even after repeated charge–discharge cycles. Such a combination of high ionic conductivity, tensile strength with low thermal shrinkage is seen to be very rare in polymer-based separators. It is noteworthy that this novel GPE outperformed the commercial separator also in the cycle performance. POLYM. COMPOS., 40:2320–2334, 2019. © 2018 Society of Plastics Engineers. © 2018 Society of Plastics Engineers