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Anila B.N.,Government College Kottayam | Nair M.K.M.,Maharajas College | Sreedharan J.,Mahatma Gandhi University | Sylas V.P.,Mahatma Gandhi University
Asian Journal of Chemistry | Year: 2017

The synthesis and characterization of perchlorate, nitrate, chloride, bromide and iodide complexes of cobalt(II) with a new Schiff base ligand 2,3-(diimino-4′- antipyrinyl)butane prepared from 4-aminoantipyrine and 2,3-butanedione have been done by elemental analysis, electrical conductance in non-aqueous solvents, infrared and electronic and 1H NMR spectra as well as thermogravimetry. The UV-visible, magnetic susceptibility and ESR spectral data suggest an octahedral geometry around the central metal ion in chloro and bromo complexes and a tetrahedral geometry around the central metal ion for perchlorate, nitrate and iodide complexes. The molecular modeling of the proposed structure is in agreement with the above mentioned structure. Biological screening analyses of the ligands and the cobalt(II) complexes reveals that the Schiff base and its cobalt(II) complexes show significant activity against microorganisms. Binding studies of Co(II) complexes with calf thymus DNA (CT DNA) were studied by spectral methods such as absorption spectroscopy through the ethidium bromide (EB) displacement technique and viscosity measurements. The results obtained indicate that the complexes bind to DNA via intercalation. © 2017, Chemical Publishing Co. All rights reserved.


Parameswaranpillai J.,Cochin University of Science and Technology | Sidhardhan S.K.,Cochin University of Science and Technology | Jose S.,Government College Kottayam | Hameed N.,Swinburne University of Technology | And 5 more authors.
Industrial and Engineering Chemistry Research | Year: 2016

In this paper, we report on the effect of curing agents on the miscibility, morphology, thermomechanical properties, and surface hydrophobicity of diglycidyl ether of bisphenol A (DGEBA)/poly(ϵ-caprolactone) (PCL) blends. Two curing agents, 4,4′-diamino diphenylsulfone (DDS) and 4,4′-diamino diphenylmethane (DDM), were used. Studies revealed that the epoxy/PCL/DDM system was completely miscible due to the intermolecular hydrogen bonding interactions between carbonyl groups of PCL and hydroxyl groups of epoxy resin. On the other hand, the epoxy/PCL/DDS system exhibited phase separated matrix/droplet type morphology, primarily due to the intramolecular hydrogen bonding interactions within the epoxy phase between sulfonyl groups of DDS and hydroxyl groups generated during epoxy-DDS reaction. The storage modulus of the epoxy/PCL/DDM system was greater than that of the epoxy/PCL/DDS system, and the dependence of modulus on PCL content was more pronounced in the former. Moreover, the epoxy/PCL/DDM system exhibited better tensile properties and thermal stability. © 2016 American Chemical Society.


Parameswaranpillai J.,Cochin University of Science and Technology | Joseph G.,Cochin University of Science and Technology | Shinu K.P.,Cochin University of Science and Technology | Jose S.,Government College Kottayam | And 2 more authors.
RSC Advances | Year: 2015

In this article, we report on a simple and cost effective approach for the development of light-weight, super-tough and stiff material for automotive applications. Nanocomposites based on PP/PS blend and exfoliated graphene nanoplatelets (xGnP) were prepared with and without SEBS. Mechanical, crystallization and thermal degradation properties were determined and correlated with phase morphology. The addition of xGnP to PP/PS blend increased the tensile modulus at the expense of toughness. The presence of xGnP increased the enthalpy of crystallization and enthalpy of fusion of PP in the blends, without affecting segmental mobility and thermal stability. Addition of polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) improved the toughness of PP/PS blends, but decreased the stiffness. The incorporation of xGnP into this ternary blend generated a super-tough material with improved stiffness and tensile elongation, suitable for automotive applications. It is observed that the presence of SEBS diminished the tendency of agglomeration of xGnP and their unfavorable interactions with thermoplastics, which in turn reduced the internal friction in the matrix. © 2015 The Royal Society of Chemistry.


Joseph L.K.,Government College Kottayam | Suja H.,NSS College Nemmara | Sanjay G.,H+ Technology | Sugunan S.,Cochin University of Science and Technology | And 2 more authors.
IOP Conference Series: Materials Science and Engineering | Year: 2015

In this paper, the optical absorption and fluorescence studies on rhodamine B (RB) intercalated acid activated K-10 montmorillonite dispersions is presented. The aqueous dispersions were prepared from the dried dye intercalated montmorillonite. The absorption and fluorescence peaks of RB dispersions show a bathochromic shift with respect to the dye concentrations. The samples have a fluorescent emission at 421 nm which is having an intensity variation depending on the concentration of the dyes. The behaviour of samples of same concentration prepared by two different routes is also presented. © Published under licence by IOP Publishing Ltd.


Parameswaranpillai J.,Cochin University of Science and Technology | Joseph G.,Cochin University of Science and Technology | Jose S.,Government College Kottayam | Hameed N.,Deakin University
Journal of Applied Polymer Science | Year: 2015

In this article, we discuss the phase morphology, thermal, mechanical, and crystallization properties of uncompatibilized and compatibilized polypropylene/polystyrene (PP/PS) blends. It is observed that the Young's modulus increases, but other mechanical properties such as tensile strength, flexural strength, elongation at break, and impact strength decrease by blending PS to PP. The tensile strength and Young's modulus of PP/PS blends were compared with various theoretical models. The thermal stability, melting, and crystallization temperatures and percentage crystallinity of semicrystalline PP in the blends were marginally decreased by the addition of amorphous PS. The presence of maleic anhydride-grafted polypropylene (compatibilizer) increases the phase stability of 90/10 and 80/20 blends by preventing the coalescence. Hence, finer and more uniform droplets of PS dispersed phases are observed. The compatibilizer induced some improvement in impact strength for the blends with PP matrix phase, however fluctuations in modulus, strength and ductility were observed with respect to the uncompatibilized blend. The thermal stability was not much affected by the addition of the compatibilizer for the PP rich blends but shows some decrease in the thermal stability of the blends, where PS forms the matrix. On the other hand, the % crystallinity was increased by the addition of compatibilizer, irrespective of the blend concentration. © 2015 Wiley Periodicals, Inc.


Ajay K.K.,National Institute of Oceanography of India | Ajay K.K.,Government College Kottayam | Chaubey A.K.,National Institute of Oceanography of India | Krishna K.S.,National Institute of Oceanography of India | And 2 more authors.
Journal of Earth System Science | Year: 2010

Multi-channel seismic reflection profiles across the southwest continental margin of India (SWCMI) show presence of westerly dipping seismic reflectors beneath sedimentary strata along the western flank of the Laccadive Ridge - northernmost part of the Chagos-Laccadive Ridge system. Velocity structure, seismic character, 2D gravity model and geographic locations of the dipping reflectors suggest that these reflectors are volcanic in origin, which are interpreted as Seaward Dipping Reflectors (SDRs). The SDRs; 15 to 27 km wide overlain by ~1 km thick sediment; are observed at three locations and characterized by stack of laterally continuous, divergent and off-lapping reflectors. Occurrence of SDRs along western flank of the Laccadive Ridge adjacent to oceanic crust of the Arabian Basin and 2D crustal model deduced from free-air gravity anomaly suggest that they are genetically related to incipient volcanism during separation of Madagascar from India. We suggest that (i) SWCMI is a volcanic passive margin developed during India-Madagascar breakup in the Late Cretaceous, and (ii) continent-ocean transition lies at western margin of the Laccadive Ridge, west of feather edge of the SDRs. Occurrence of SDRs on western flank of the Laccadive Ridge and inferred zone of transition from continent to ocean further suggest continental nature of crust of the Laccadive Ridge. © Indian Academy of Sciences.


Jose S.,Government College Kottayam | Thomas S.,Mahatma Gandhi University | Biju P.K.,Mahatma Gandhi University | Karger-Kocsis J.,Budapest University of Technology and Economics
Journal of Polymer Research | Year: 2013

The mechanical and dynamic mechanical properties of isotactic polypropylene/high density polyethylene (PP/HDPE) blends, as a function of blend ratio and compatibiliser concentration were analysed. Ethylene propylene random copolymers (EPDM) with three different monomer fractions were used as compatibilisers. Compatibilisation improved the mechanical properties (except Young's modulus) of the blends, considerably. The compatibiliser with 1:1 monomer fraction was found to be most efficient. A detailed discussion on the fundamental reasons responsible for the deterioration of properties in the absence of compatibilisers and the improvement of properties in the presence of compatibilisers was presented. The tensile strength of the uncompatibilised blends was theoretically modelled using Nielsen's and Nicolais-Narkis models. The Young's and storage moduli of uncompatibilised blends were compared with those predicted by various theoretical models. Attention was paid to correlate the mechanical properties of both compatibilised and uncompatibilised blends with their phase morphology. © Springer Science+Business Media Dordrecht 2013.


Jose S.,Government College Kottayam | Thomas S.,Mahatma Gandhi University | Aravind I.,Devaswamboard College | Karger-Kocsis J.,Budapest University of Technology and Economics
International Journal of Plastics Technology | Year: 2014

The phase morphology and rheology of polyamide 12/polypropylene (PA12/PP) blends have been studied. Effects of blend ratio and reactive compatibilisation on the rheological properties of compatibilised and uncompatibilised blends were analysed. The viscosity ratio between the polymers was found to be sensitive to frequency. The complex viscosity and dynamic modulus increased with increase in the amount of compatibiliser, up to critical micelle concentration. The interfacial tension between the polymers was calculated from the storage modulus of the blends using Palierne and Choi-Schowalter models. It was found that the rheological properties of both compatibilised and uncompatibilised blends are intimately related to their phase morphology. © 2014, Central Institute of Plastics Engineering & Technology.

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