Facultyhttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/4902024-02-07T20:41:38Z2024-02-07T20:41:38ZHDPE-Ash NanocompositesEby Thomas, ThachilAyswarya, E PBeena, Abraham Thttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/47192014-09-22T20:30:15Z2011-10-20T00:00:00ZHDPE-Ash Nanocomposites
Eby Thomas, Thachil; Ayswarya, E P; Beena, Abraham T
Ash-based polymer composites are assuming
increasing importance because of the pollutant potential,
fine particle size, and low price of ash. Fly ash and
rice husk ash are two prominent ash materials on which
some investigations have already been done for potential
use in polymer composites. This article highlights the
results of a study on the use of wood ash in HDPE. Wood
ash is mainly a mixture of various metallic compounds
and some silica. Here, the characterization of wood ash
has been done with the help of XRD, ICPAES, light scattering
based particle size analysis, FTIR, and SEM. The
results show that wood ash particle size has an average
value of 293 nm, much lower than other categories of ash.
When blended with HDPE in the presence of a compatibilizer,
wood ash gives rise to vastly improved mechanical
properties over that of the base polymer. The results
prove that wood ash is a valuable reinforcing material for
HDPE and the environmental pollution due to wood ash
can be solved in a most profitable way by this technique.
Journal of Applied Polymer Science, Vol. 124, 1659–1667 (2012)
2011-10-20T00:00:00ZCharacterization of Linear Low-Density Polyethylene/ Poly(vinyl alcohol) Blends and Their Biodegradability by Vibrio sp. Isolated from Marine Benthic EnvironmentEby Thomas, ThachilSarita, Bhat GRaghul Subin, SVidya, Francishttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/47182014-09-22T20:30:13Z2011-10-04T00:00:00ZCharacterization of Linear Low-Density Polyethylene/ Poly(vinyl alcohol) Blends and Their Biodegradability by Vibrio sp. Isolated from Marine Benthic Environment
Eby Thomas, Thachil; Sarita, Bhat G; Raghul Subin, S; Vidya, Francis
Increasing amounts of plastic waste in the
environment have become a problem of gigantic proportions.
The case of linear low-density polyethylene (LLDPE)
is especially significant as it is widely used for packaging
and other applications. This synthetic polymer is normally
not biodegradable until it is degraded into low molecular
mass fragments that can be assimilated by microorganisms.
Blends of nonbiodegradable polymers and biodegradable
commercial polymers such as poly (vinyl alcohol)
(PVA) can facilitate a reduction in the volume of plastic
waste when they undergo partial degradation. Further, the
remaining fragments stand a greater chance of undergoing
biodegradation in a much shorter span of time. In this
investigation, LLDPE was blended with different proportions
of PVA (5–30%) in a torque rheometer. Mechanical,
thermal, and biodegradation studies were carried out on
the blends. The biodegradability of LLDPE/PVA blends
has been studied in two environments: (1) in a culture medium
containing Vibrio sp. and (2) soil environment, both
over a period of 15 weeks. Blends exposed to culture medium
degraded more than that exposed to soil environment.
Changes in various properties of LLDPE/PVA
blends before and after degradation were monitored using
Fourier transform infrared spectroscopy, a differential
scanning calorimeter (DSC) for crystallinity, and scanning
electron microscope (SEM) for surface morphology among
other things. Percentage crystallinity decreased as the PVA
content increased and biodegradation resulted in an
increase of crystallinity in LLDPE/PVA blends. The results
prove that partial biodegradation of the blends has
occurred holding promise for an eventual biodegradable
product
Journal of Applied Polymer Science, Vol. 124, 257–265 (2012)
2011-10-04T00:00:00ZMicrowave exfoliated reduced graphene oxide epoxy nanocomposites for high performance applicationsEby Thomas, ThachilBindu, Sharmila T KAjalesh, Nair BBeena, Abraham TSabura Begum, P Mhttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/46942014-09-12T06:08:24Z2014-05-22T00:00:00ZMicrowave exfoliated reduced graphene oxide epoxy nanocomposites for high performance applications
Eby Thomas, Thachil; Bindu, Sharmila T K; Ajalesh, Nair B; Beena, Abraham T; Sabura Begum, P M
Graphene has captured the attention of scientific community due to recently emerging high performance
applications. Hence, studying its reinforcing effects on epoxy resin is a significant step. In this study,
microwave exfoliated reduced graphene oxide (MERGO) was prepared from natural graphite for subsequent
fabrication of epoxy nanocomposites using triethylenetetramine (TETA) as a curing agent via insitu
polymerization. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy,
Fourier transform infrared spectroscopy (FTIR), C13 NMR spectroscopy, X-ray photoelectron spectroscopy
(XPS) and ultravioletevisible (UVevis) spectroscopy were employed to confirm the simultaneous
reduction and exfoliation of graphene oxide. The reinforcing effect of MERGO on epoxy resin was
explored by investigating its static mechanical properties and dynamic mechanical analysis (DMA) at
MERGO loadings of 0 to 0.5 phr. The micro-structure of epoxy/MERGO nanocomposites was investigated
using scanning electron microscope (SEM), transmission electron microscope (TEM) and XRD techniques.
The present work reports an enhancement of 32%, 103% and 85% in tensile, impact and flexural strength
respectively of epoxy by the addition of even 0.25 phr MERGO. At this loading elastic and flexural moduli
also increased by 10% and 65%, respectively. Single-edge-notch three-point-Bending (SEN-TPB) fracture
toughness (KIC) measurements were carried out where a 63% increase was observed by the introduction
of 0.25 phr MERGO. The interfacial interactions brought about by graphene also benefited the dynamic
mechanical properties to a large extent in the form of a significant enhancement in storage modulus and
slightly improved glass transition temperature. Considerable improvements were also detected in
dielectric properties. The epoxy nanocomposite also attained an ac conductivity of 10 5 S/m and a
remarkable increase in dielectric constant. The simple and cost effective way of graphene synthesis for
the fabrication of epoxy/MERGO nanocomposites may be extended to the preparation of other MERGO
based polymer nanocomposites. This remarkable class of materials has thrown open enormous opportunities
for developing conductive adhesives and in microelectronics
Polymer 55 (2014) 3614e3627
2014-05-22T00:00:00ZUtilization of waste expanded polystyrene: Blends with silica-filled natural rubberEby Thomas, ThachilBeena, Thattekatt AbrahamRenju, Vaikathusseril Sekharanhttp://dyuthi.cusat.ac.in:8080/xmlui/handle/purl/46932014-08-30T20:30:11Z2012-03-01T00:00:00ZUtilization of waste expanded polystyrene: Blends with silica-filled natural rubber
Eby Thomas, Thachil; Beena, Thattekatt Abraham; Renju, Vaikathusseril Sekharan
Expanded polystyrene (EPS) constitutes a considerable part of thermoplastic waste in the environment in
terms of volume. In this study, this waste material has been utilized for blending with silica-reinforced
natural rubber (NR). The NR/EPS (35/5) blends were prepared by melt mixing in a Brabender Plasticorder.
Since NR and EPS are incompatible and immiscible a method has been devised to improve compatibility.
For this, EPS and NR were initially grafted with maleic anhydride (MA) using dicumyl peroxide (DCP) to
give a graft copolymer. Grafting was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy.
This grafted blend was subsequently blended with more of NR during mill compounding. Morphological
studies using Scanning Electron Microscopy (SEM) showed better dispersion of EPS in the
compatibilized blend compared to the noncompatibilized blend. By this technique, the tensile strength,
elongation at break, modulus, tear strength, compression set and hardness of the blend were found to be
either at par with or better than that of virgin silica filled NR compound. It is also noted that the thermal
properties of the blends are equivalent with that of virgin NR. The study establishes the potential of this
method for utilising waste EPS
Materials and Design 40 (2012) 221–228
2012-03-01T00:00:00Z