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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. Source

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. Source

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. Source

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. Source

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. Source

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