Tolune diisocyanate (TDI) is an isocyanate used in the production of
polyurethanes for flexible foam applications, ranging from furniture, bedding,
and carpet underlay to transportation and packaging. TDI is also used in the
manufacture of coatings, sealants, adhesives and elastomers.
Nylon is a generic designation for a family of synthetic polymers known
generically as aliphatic polyamides derived from benzene, first produced in
1935 by DuPont. Nylon can be used to form fibers, filaments, bristles, or
sheets to be manufactured into yarn, fabric, and cordage; and it can be
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formed into molded products. Nylon is tough, elastic and strong, and it has
high resistance to wear, heat, and chemicals. It is generally used in the form
of fine filaments in such articles as hosiery and sports equipment, e.g.,
parachutes; but its applications also include engineering plastics for cars,
toys, healthcare products, carpets, roller-blade wheels and ship sails.
There are many varieties of nylon that have their own characteristic
properties. Nylon plastics are used for making such products as combs,
brushes and gears. Nylon yarns, on the other hand, are used for making
nylon fabrics. When talking about nylon textile, there are two types that are
mostly prevalent in the market: nylon 6-6 (also written as nylon 6,6) and
nylon 6.
Phenol is an aromatic alcohol, mainly used as an intermediate in organic
synthesis. Essentially, it serves as a raw material for the production of
bisphenol A, phenolic resins, alkylphenols and caprolactam. It is a
poisonous, acidic compound obtained from coal tar or benzene and used
mainly as a disinfectant or antiseptic, carbolic acid; any hydroxyl derivative of
benzene.
Phenolic resins are manufactured from phenol. They are used in wood
products and molding powders applications, and also have a wide range of
applications on the electrical, mechanical and decorative markets, in the
automotive industry, in building and construction, in thermal insulation
products and in foundry industry products.
Epoxy resin is a flexible resin made using phenols and used chiefly in
coatings, adhesives, electrical laminants and composites for its excellent
adhesion, strength and chemical resistance.
Polycarbonates are a particular group of thermoplastics. They are easily
worked, molded, and thermoformed; as such, these plastics are very widely
used in modern manufacturing. Polycarbonate is becoming more common in
housewares, as well as laboratories and in industry. It is often used to create
protective features, for example, in banks as well as vandal-proof windows
and lighting lenses for many buildings.
7.1.3 Benzene and styrenic chain, derivatives
Polystyrene is solid plastic made from polymerized styrene. It is the second
most common plastic and used in a wide variety of everyday applications,
from coffee cups to CD jewel boxes. It is a thermoplastic polymer in a solid
“glassy” state at room temperature, but flows if heated above about 100 °C.
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It becomes solid again when cooled. This allows polystyrene to be extruded,
molded and vacuum-formed in molds with fine detail and high finish.
Figure 26. Aromatics – benzene and styrenic chain, derivatives
Styrene-acrylonitrile (SAN) is like polystyrene but offers higher thermal
resistance and is therefore used mainly in the automotive, electrical and
electronics industry, as well as in household applications and building
products.
Acrylonitrile-butadiene-styrene (ABS) is a tough, heat-resistant and impactresistant thermoplastic, with the acrylonitrile providing heat resistance and
the styrene units offering rigidity. It is widely used for appliance and
telephone housings, luggage, sporting helmets, pipe fittings and automotive
parts.
Styrene-butadiene rubber (SBR) is a rubber manufactured from styrene.
Because of its excellent abrasion resistance, it is widely used in automobile
and truck tires, as well as for carpet backing and paper coating. About 50%
of a car tire is made from SBR. Other applications are in belting, flooring,
wire and cable insulation and footwear.
7.2 Olefins
Olefins are petrochemical derivatives produced by cracking feed stocks from
raw materials such as natural gas and crude oil. Lower olefins have short
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chains with only two, three or four carbon atoms, and the simplest one is
ethylene. The higher olefins have chains of up to twenty or more carbon
atoms. The main olefin products are ethylene, propylene, butadiene and C4
derivatives. They are used to produce plastics, as chemical intermediates,
and, in some cases, as industrial solvents.
7.2.1 Ethylene, derivatives
Figure 27. Olefins – ethylene, derivatives
Polyester and polyester resins is described under the Aromatics chain
(Chapter 7.1.1).
Ethanol, also known as ethyl alcohol (common alcohol), is manufactured by
synthesis from ethylene. It is an oxygenated hydrocarbon used in a wide
variety of high performance solvent applications (toiletries and cosmetics,
paints, lacquer thinners, printing inks, dyes, detergents, disinfectants and
pharmaceuticals), as a chemical raw material for the production of a range of
monomers and solvents, and is essential in pharmaceutical purification. In
transportation, ethanol is used as a vehicle fuel by itself, blended with
gasoline, or as a gasoline octane enhancer and oxygenate.
Ethanolamines are prepared by the reaction of ammonia and ethylene oxide.
They include monoethanolamine (MEA), diethanolamine (DEA) and
triethanolamine (TEA). The three are widely used in industry, principally as
absorbents for acidic components of natural gas and of petroleum-refinery
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gas streams. It is also used to make detergents, metalworking fluids, and as
gas sweetening. TEA is used in detergents and cosmetics applications and
as a cement additive.
Polyethylene (PE), with a world production around 80 million tons, is the
most common plastic (and polymer). It is a polymer of ethylene, especially
any of various lightweight thermoplastics that are resistant to chemicals and
moisture, and has good insulating properties. Its primary use is in packaging
(plastic bags, plastic films, geomembranes, containers including bottles,
etc.).
Many kinds of polyethylene are known, with most having the chemical
formula (C2H4)nH2. It has many different trade varieties, and the most
common are:
High-density polyethylene (HDPE) is used predominantly in the
manufacture of blow-molded bottles for milk and household cleaners
and injection-molded pails, bottle caps, appliance housings and toys.
Low-density polyethylene (LDPE) is used in film applications due
to its toughness,
flexibility and relative transparency. Typically,
LDPE is used to manufacture flexible films such as those used for
plastic retail bags. LDPE is also used to flexible lids and bottles, in
wire and cable applications for its stable electrical properties and
processing characteristics.
Linear low-density polyethylene (LLDPE) is used predominantly in
film applications due to its toughness, flexibility and relative
transparency. LLDPE is the preferred resin for injection molding
because of its superior toughness
Polyvinyl chloride (PVC). A polymer of vinyl chloride is used to make a
diverse range of cost-effective products with various levels of technical
performance suited to a wide range of applications. Many of these PVC
products are used every day and include everything from medical devices
such as medical tubing and blood bags, to footwear, electrical cables,
packaging, stationery and toys.
