3. Description:
• Polystyrene is a synthetic polymer made from
the monomer styrene, a liquid petrochemical.
• Polystyrene can be rigid or foamed.
• General polystyrene is clear, hard and brittle.
• It is a very inexpensive resin per unit weight.
• It is a rather poor barrier to oxygen and water
vapor.
4. Origin and history:
• Polystyrene was discovered in 1839 by Eduard
Simon, in Berlin.
• From the resin of a tree, he distilled an oily
substance, a monomer that he named styrol.
• Days later, Simon found that the styrol had
thickened, presumably from oxidation, into a jelly he
dubbed styrol oxide.
• They called their substance metastyrol.
• But later the substance receiving its present name,
polystyrene.
5. Properties:
PS
Polystyrene
• Thermal properties: The "compact" polystyrene presents
the lowest thermal conductivity of all thermoplastics.
• Optical properties: While the PS shock is fully opaque,
the PS Crystal is transparent.
• Electrical properties: Polystyrene has very low electrical
conductivity, in other words, it is an insulator.
7. Recycling:
• In general, polystyrene is not accepted
in recycling programs, and is not separated and
recycled where it is accepted.
• In Germany, polystyrene is collected, as a
consequence of the packaging law that requires
manufacturers to take responsibility for
recycling or disposing of any packaging material
they sell.
8. Ampliation:
• Polystyrene foam is a major environmental
problem. Used in the packaging of products and
transportation industry, occurs in the world tons
of it each year. The fact that it is not recyclable
increases the ecological impact.
Contamination by polystyrene foam in landfills.
10. WHAT IS POLYURETHANE ?
• Polyurethane (PUR and PU) is a polymer
composed of a chain of organic units joined by
carbamate (urethane) links. While most
polyurethanes are thermosetting polymers that
do not melt when heated, thermoplastic
polyurethanes are also available.
11. HISTORY OF POLYURETHANE
• Polyurethanes can be found in liquid coatings and paints, tough
elastomers such as roller blade wheels, rigid insulation, soft flexible
foam, elastic fiber or as an integral skin. No matter how
polyurethane is transformed, the underlying chemistry is the result
of one man’s genius, Prof. Dr. Otto Bayer (1902-1982). Prof. Dr.
Otto Bayer is recognized as the “father” of the polyurethanes
industry for his invention of the basic diisocyanate polyaddition
process.
• The origin of polyurethane dates back to the beginning of World
War II, when it was first developed as a replacement for rubber. The
versatility of this new organic polymer and its ability to substitute
for scarce materials spurred numerous applications. During World
War II, polyurethane coatings were used for the impregnation of
paper and the manufacture of mustard gas resistant garments, highgloss airplane finishes and chemical and corrosion-resistant
coatings to protect metal, wood and masonry.
12. HOW POLYURETHANE IS MADE
• Polyurethane chemistry is complex, but the basics
are relatively easy to understand. Polyurethanes are
formed by reacting a polyol (an alcohol with more
than two reactive hydroxyl groups per molecule)
with a diisocyanate or a polymeric isocyanate in the
presence of suitable catalysts and additives. Because
a variety of diisocyanates and a wide range of
polyols can be used to produce polyurethane, a
broad spectrum of materials can be produced to
meet the needs for specific applications.
13. POLYURETHANE APPLICATIONS
• Heating and cooling costs amount to about 56 percent of the
energy used in the average American home, according to the
U.S. Department of Energy. The nature of the chemistry
allows polyurethanes to be adapted to solve challenging
problems, to be molded into unusual shapes and to enhance
industrial and consumer products.
• Polyurethanes are formed by reacting a polyol (an alcohol
with more than two reactive hydroxyl groups per molecule)
with a diisocyanate or a polymeric isocyanate in the presence
of suitable catalysts and additives. Because a variety of
diisocyanates and a wide range of polyols can be used to
produce polyurethane, a broad spectrum of materials can be
produced to meet the needs of specific applications.
14. PROPERTIES OF POLYURETHANE
• Continuous insulation with joints: eliminates thermal bridges.
• Waterproofing (high density).
• “Autoahderente “ , to any surface or material used in construction.
• Light weight: no “sobre caraga “structures.
• Indefinite Duration.
• Total sealing.
• Chemical resistance.
• Fire resistance.
15. POLYURETHANE FORMS
• Polyurethanes exist in a variety of forms,
including flexible foams, rigid foams, chemicalresistant coatings, specialty adhesives and
sealants, and elastomers.
• Rigid :
Flexible:
17. The Accident !
• Polyethylene was first synthesized by German
chemist Hans von Pechmann who prepared it by
accident in 1898, while heating diazomethane on
the stove. When his colleagues Eugen
Bamberger and Friedrich Tschirner investigated
the white oily substance created, they discovered
long chains composed of-CH2-and called it
polymethylene. March 27, 1933, in England, was
synthesized as we know it today, by Reginald
Gibson and Eric Fawcett who worked for ICI
Laboratories.
18. Characteristics
• Excellent electrical insulator.
• . Transparent, opaque or attractive colors.
• . Resistant to low temperatures.
• . Hygienic and safe.
• . Inert to chemical attack.
• . Excellent moisture barrier.
• . Economic.
19. Its Uses
• All sorts of bags : supermarkets,
boutiques,bakery,frosts etc.
• Coating ditches
• Automatic food packaging and industrial products,
such as Milk, water, plastics, etc.
• Base for disposable nappies.
• Serum bags.
• Domestic airtight containers
• Pipes and knobs: cosmetics, medicines and food
• Irrigation pipes
• Bottles , draws
20. Recycling !
The Polyethylene is recyclable,it means, that we
can melt it again and transform it in new
products such as plastic wood for sticks film for
agriculture etc.
