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The Society
of Plastics Engineers, Inc. (SPE):
A technical society
for the plastics industry that is a preferred supplier
of engineering, scientific and business knowledge required
by the SPE membership. Its goal is to promote this knowledge
and increase education of plastics and polymers worldwide.
(Leadership 2000: Strategies for the Next Century, SPE,
1996).
The
Society of the Plastics Industry, Inc. (SPI):
A trade organization of more than 2,000 members representing
all segments of the plastics industry in the United
States. SPI's operating units and committees are composed
of resin manufacturers, distributors, machinery manufacturers,
plastics processors, moldmakers and other industry-related
groups and individuals. (SPI Boilerplate, 1996).
Solid Waste:
Garbage, refuse, sludges, and other discarded solid
materials resulting from industrial and commercial operations
and from community activities. It does not include solids
or dissolved material in domestic sewage or other significant
pollutants in water resources, such as silt, dissolved
or suspended solids in industrial wastewater effluents,
dissolved materials in irrigation return flows or other
common water pollutants. (Code of Federal Regulations,
Title 40, §240.101).
Source Reduction:
The design, manufacture, use or reuse of materials or
products (including packages) to reduce their amount
or toxicity throughout their useful life and when they
are reused, recycled, landfilled or incinerated. Because
it is intended to reduce pollution and conserve resources,
source reduction should not increase the net amount
or toxicity of wastes generated throughout the life
of a product. Source reduction is sometimes referred
to as waste prevention. (National Recycling Coalition:
Definitions Approved by NRC Board of Directors, September
10, 1995).
Source Separation:
The sorting of individual secondary materials at the
point of collection or generation for recycling. Many
curbside recycling programs require the hauler to separate
paper, glass, metal cans and plastic containers into
their appropriate bins on the truck when collected.
(The Recycler's Lexicon: A Glossary of Contemporary
Terms and Acronyms, Resource Recycling Inc., 1995).
Stabilizers:
Stabilizers increase both virgin resin's and post-consumer
plastic plastic's strength and resistance to degradation.
Heat stabilizers provide resistance to thermal degradation
during periods of exposure to elevated temperatures.
Thermal degradation is reduced not only during processing
but also during the useful life of the finished products.
Light stabilizers are used in a variety of resins to
limit the effects of sunlight or other sources of ultra
violet radiation. Antioxidants can be used as sacrificial
Additives to protect plastics from oxidizing environments.
Stabilizers are important for post-consumer plastic
plastics because reprocessing exposes the material to
additional heat histories through compounding and molding.
It is also important to replenish sacrificial Additives
that might have been expended during the material's
previous application and/or during the added heat histories.
(Adapted from Modern Plastics Encyclopedia 1995).
STYROFOAM:
STYROFOAM is a trademarked name for a specific form
of insulation manufactured by The Dow Chemical Company.
"STYROFOAM" is not synonymous with "polystyrene."
Sustainable Development:
To meet the needs of the present without compromising
the ability of future generations to meet their own
needs. (The World Commission on Environment and Development,
Our Common Future, Oxford University Press, 1987).
Scanning Electron
Microscopy (SEM)
In Scanning Electron Microscopy (SEM) a focused beam
of electrons scans across the surface of the sample.
It is detected synchronously to the position of the
scanning electron beam and recorded in an image storage
device. Differencies in the topography of the sample
give rise to the differencies in the intensities of
the signals formed by the secondary electrons in the
detector resulting in a three dimensional image. Scanning
electron microscopy is suited to most types of surface
morphology studies. Rough topographic features, void
content and particle agglomerations are easily revealed
as well as the compositional differencies within material.
Energy Dispersive X-ray Spectroscopy (EDS) or Wavelength
Dispersive X-Ray Spectroscopy (WDS) in conjunction with
SEM allows elemental analyses to be performed directly
over the surface of the sample.
Shear thinning
A behaviour where the viscosity decreases when the shear
stress increases. Typically broadening of the molecular
weight distribution increases shear thinning.
Shore Hardness
Resistance of a (polymer) surface to deformation. The
different hardness measures applied for characterising
polymers are:
(a) Shore hardness (two scales, A for softer and D for
harder materials)
(b) Ball indentation hardness (also useable on profiled
surfaces because of bigger measuring device).
Single Site Catalysts
Produces stereospecific polymers having very narrow
MWD, very uniform comonomer distribution. Usually cocatalyst
required.
Solution Viscometry
In Solution Viscometry the rate at which a dilute polymer
solution flows through a capillary is measured. Temperature
and concentration of the polymer are carefully controlled.
The parameter most often determined by dilute solution
viscometry is intrinsic viscosity. Intrinsic viscosity
is related to molar mass through a semi-empirical relationship
called Mark-Houwink's equation.
Sponge Rubber
Vulcanized rubber having a porous or cellular structure
like that of a sponge, made by incorporating gasifying
substances or blowing agents such as sodium bicarbonate
and ammonium carbonate in the mixing, and then vulcanizing
in a mold cavity larger than the piece of rubber to
be vulcanized. Gas is generated from the dispersed particles
of the blowing agent, producing the porous structure
and inflating the rubber to the size of the mold cavity.
Star macromolecule
A macromolecule containing a constitutional unit from
which more than two chains (arms) emanate. A star macromolecule
with n linear chains (arms) attached to the central
unit is termed an n-star, e.g., five-star.
Supercritical state
The critical state of a fluid is when the liquid and
gas phase both have the same density. The fluid is then
at its critical temperature, critical pressure, and
critical volume. When the pressure or temperature exceeds
this, the fluid is in its supercritical state. The loop
reactor in the BORSTAR process is operated in supercritical
state for some products.
Swelling
The property of a raw or vulcanized rubber of absorbing
organic liquid, such as benzene and gasoline, and swelling
to many times it's original volume; the property is
also shown by other colloids in contact with other liquids;
in a general sense, it may be any increase in volume
in a solid substance caused by the absorption of a liquid.
Syndiotactic macromolecule
A macromolecule comprising alternating enantiomeric
configurational base units. Note: in a syndiotactic
macromolecule, the configurational repeating unit consists
of two configurational base units that are enantiomeric
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Plastic
Brief
