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Feedstock
Recycling:
A group of recycling technologies employing various
processes that convert mixtures of plastics into petroleum
feedstocks or raw materials that can be used in refineries
and petrochemical facilities for making new products.
These technologies augment existing mechanical systems
as part of an integrated approach to plastics recycling
designed to increase the volume of post-consumer plastic
plastics diverted from the waste stream and expand the
variety of plastics that are recycled into new and useful
products. (The Evolution of Plastics Recycling Technology,
APC, 1994).
FTIR
Spectroscopy
Infrared radiation induces vibrations of molecules and
molecular segments. Absorption of radiation occurs only
if the vibration results in the change of the molecular
dipole moment. The strength of the vibrating bonds and
their dipole moment affect the absorption band intensities
and positions which makes FTIR spectroscopy a very useful
method in qualitative polymer analysis. Also several
fast quantitative FTIR methods have been developed for
the structural characterisation of polyolefins.
Polymer crystallinity and orientation implies a restriction
in the movement of some molecules and consequent improvement
in polymer mechanical properties. This restriction in
the movements reflects also to the FTIR spectrum and
thus the amorphous and crystalline polymer phases can
be identified.
Flammability
The characteristics of a material that pertain to it's
relative ease of ignition and relative ability to sustain
combustion.
Flexural
test
Like tensile test, flexural test is also used to characterize
strength and stiffness of the material. Flexural properties
are obtained by placing a specimen horizontally on two
supports. A load is applied at a specified rate in the
center, normal to specimen longitudinal axis. Measured
force - deformation data is used to calculate flexural
modulus and flexural strength. Flexural tests can be
used if material is too brittle to withstand compressive
forces of fixing in tensile grips.
Flory-Huggins
theory
A thermodynamic theory of polymer solutions, first formulated
independently by Flory and by Huggins, in which the
thermodynamic quantities of the solution are derived
from a simple concept of combinational entropy of mixing
and a reduced Gibbs-energy parameter, the `X parameter'.
The X parameter is a numerical parameter employed in
the Flory-Huggins theory, which accounts in the main
for the contribution of the non-combinational entropy
of mixing and for the enthalpy of mixing
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Plastic
Brief
