Nisha, Nandakumar; Dr. Philip, Kurian(Cochin University of Science And Technology, December 11, 2013)
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Abstract:
The Human race of our century is in gluttonous search for novel engineering
products which led to a skyrocketed progress in research and fabrication of filled
polymers. Recently, a big window has been opened up for speciality polymers
especially elastomers with promising properties. Among the many reasons why
rubbers are widely used in the process industries, three are considered as
important. Firstly, rubbers operate in a variety of environments and possess usable
ranges of deformity and durability and can be exploited through suitable and more
or less conventional equipment design principles. Secondly, rubber is an eminently
suitable construction material for protection against corrosion in the chemical plant
and equipment against various corrosive chemicals as, acids and alkalies and if
property tailored, can shield ionising radiations as X-rays and gamma rays in
medical industry, with minimum maintenance lower down time, negligible
corrosion and a preferred choice for aggressive corroding and ionising
environment. Thirdly, rubber can readily and hastily, and at a relatively lower cost,
be converted into serviceable products, having intricate shapes and dimensions. In a
century’s gap, large employment of flexible polymer materials in the different
segments of industry has stimulated the development of new materials with special
properties, which paved its way to the synthesis of various nanoscale materials. At
nano scale, one makes an entry into a world where multidisciplinary sciences meet
and utilises the previously unapproached infinitesimal length scale, having
dimension which measure upto one billionth of a meter, to create novel properties.
The nano fillers augment the elastomers properties in an astonishing fashion due to
their multifunctional nature and unprecedented properties have been exhibited by
these polymer-nanocomposites just to beat the shortcomings of traditional micro
composites. The current research aims to investigate the possibility of using
synthesised nano barium sulphate for fabricating elastomer-based nanocomposites
and thereby imparting several properties to the rubber. In this thesis, nano
materials, their synthesis, structure, properties and applications are studied. The
properties of barium sulphate like chemical resistance and radiopacity have been
utilized in the present study and is imparted to the elastomers by preparing
composites
Description:
Department of Polymer Science and Rubber Technology
Cochin University of Science and Technology
Polytetrafluoroethylene (PTFE) composites
filled with Sr2Ce2Ti5O16 ceramic were prepared by a powder
processing technique. The structures and microstructures
of the composites were investigated by X-ray diffraction
and scanning electron microscopy techniques. Differential
scanning calorimetry showed that the ceramic filler
had no effect on the melting point of the PTFE. The effect
of the Sr2Ce2Ti5O16 ceramic content [0–0.6 volume fraction
(vf)] on the thermal conductivity, coefficient of thermal
expansion (CTE), specific heat capacity, and thermal diffusivity
were investigated. As the vf of the Sr2Ce2Ti5O16 ceramic increased, the thermal conductivity of the specimen
increased, and the CTE decreased. The thermal conductivity
and thermal expansion of the PTFE/Sr2Ce2Ti5O16
composites were improved to 1.7 W m21 8C21 and 34
ppm/8C, respectively for 0.6 vf of the ceramics. The experimental
thermal conductivity and CTE were compared
with different theoretical models.