Plastics Are A Wide Range Of: o o o o o o o o o

Plastics are a wide range of synthetic or semi-synthetic organic compounds that are malleable and
so can be molded into solid objects.

Plasticity is the general property of all materials which can deform irreversibly without breaking but,
in the class of moldable polymers, this occurs to such a degree that their actual name derives from
this specific ability.
Plastics are typically organic polymers of high molecular mass and often contain other substances.
They are usually synthetic, most commonly derived from petrochemicals, however, an array of
variants are made from renewable materials such as polylactic acid from corn or cellulosics from
cotton linters.[1]
In developed economies, about a third of plastic is used in packaging and roughly the same in
buildings in applications such as piping, plumbing or vinyl siding.[2] Other uses include automobiles
(up to 20% plastic[2]), furniture, and toys.[2] In the developing world, the applications of plastic may
differ—42% of India's consumption is used in packaging.[2] Worldwide, about 50 kg of plastic is
produced annually per person, with production doubling every ten years.
Plastics have many uses in the medical field as well, with the introduction of polymer implants and
other medical devices derived at least partially from plastic. The field of plastic surgery is not named
for use of plastic materials, but rather the meaning of the word plasticity, with regard to the reshaping
of flesh.
The world's first fully synthetic plastic was bakelite, invented in New York in 1907, by Leo
Baekeland[3] who coined the term 'plastics'.[4] Many chemists have contributed to the materials
science of plastics, including Nobel laureate Hermann Staudinger who has been called "the father
of polymer chemistry" and Herman Mark, known as "the father of polymer physics".[5]
The success and dominance of plastics starting in the early 20th century led to environmental
concerns regarding its slow decomposition rate after being discarded as trash due to its composition
of large molecules. Toward the end of the century, one approach to this problem was met with wide
efforts toward recycling.
Contents
 1Etymology
 2Structure
 3Properties and classifications
o 3.1Thermoplastics and thermosetting polymers
o 3.2Amorphous plastics and crystalline plastics
o 3.3Conductive polymers
o 3.4Biodegradable plastics and bioplastics
 3.4.1Bioplastics
 4Types
o 4.1Common plastics
o 4.2Specialist plastics
 5History
 6Plastics industry
o 6.1Industry standards
 7Additives
o 7.1Stabilizers
o 7.2Fillers
o 7.3Plasticizers
o 7.4Colorants
 8Toxicity
o 8.1Bisphenol A (BPA)
 9Microplastics
 10Environmental effects
o 10.1Climate change
o 10.2Production of plastics
o 10.3Incineration of plastics
o 10.4Pyrolytic disposal
o 10.5Decomposition of plastics
o 10.6Recycling
 11Representative polymers
o 11.1Bakelite
o 11.2Polystyrene
o 11.3Polyvinyl chloride
o 11.4Nylon
o 11.5Poly(methyl methacrylate)
o 11.6Rubber
o 11.7Synthetic rubber
 12See also
 13References
 14External links
Etymology
The word plastic derives from the Greek πλαστικός (plastikos) meaning "capable of being shaped or
molded" and, in turn, from πλαστός (plastos) meaning "molded".[6][7]
The plasticity, or malleability, of the material during manufacture allows it to be cast, pressed,
or extruded into a variety of shapes, such as: films, fibers, plates, tubes, bottles, boxes, amongst
many others.
The common noun plastic should not be confused with the technical adjective plastic. The adjective
is applicable to any material which undergoes a plastic deformation, or permanent change of shape,
when strained beyond a certain point. For example, aluminum which is stamped or forged exhibits
plasticity in this sense, but is not plastic in the common sense. By contrast, some plastics will, in
their finished forms, break before deforming and therefore are not plastic in the technical sense.
Structure
Most plastics contain organic polymers.[8] The vast majority of these polymers are formed
from chains of carbon atoms, 'pure' or with the addition of: oxygen, nitrogen, or sulfur. The chains
comprise many repeat units, formed from monomers. Each polymer chain will have several
thousand repeating units.
The backbone is the part of the chain that is on the "main path", linking together a large number
of repeat units.
To customize the properties of a plastic, different molecular groups "hang" from this backbone.
These pendant units are usually "hung" on the monomers, before the monomers themselves are
linked together to form the polymer chain. It is the structure of these side chains that influences the
properties of the polymer.
The molecular structure of the repeating unit can be fine tuned to influence specific properties of the
polymer.
Properties and classifications

Plastics are usually classified by: the chemical structure of the polymer's backbone and side chains;
some important groups in these classifications are: the acrylics, polyesters, silicones, polyurethanes,
and halogenated plastics.
Plastics can also be classified by: the chemical process used in their synthesis, such
as: condensation, polyaddition, and cross-linking.[9]
Plastics can also be classified by: their various physical properties, such
as: hardness, density, tensile strength, resistance to heat and glass transition temperature, and by
their chemical properties, such as the organic chemistry of the polymer and its resistance and
reaction to various chemical products and processes, such as: organic solvents, oxidation,
and ionizing radiation. In particular, most plastics will melt upon heating to a few hundred
degrees celsius.[10]
Other classifications are based on qualities that are relevant for manufacturing or product design.
Examples of such qualities and classes are: thermoplastics and thermosets, conductive
polymers, biodegradable plastics and engineering plastics and other plastics with particular
structures, such as elastomers.
Thermoplastics and thermosetting polymers
The plastic handle of a spatula that has been deformed by heat.

One important classification of plastics is by the permanence or impermanence of their form, or
whether they are: thermoplastics or thermosetting polymers. Thermoplastics are the plastics that,
when heated, do not undergo chemical change in their composition and so can be molded again and
again. Examples include: polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyvinyl
chloride (PVC).[11] Common thermoplastics range from 20,000 to 500,000 amu, while thermosets are
assumed to have infinite molecular weight.
Thermosets, or thermosetting polymers, can melt and take shape only once: after they have
solidified, they stay solid.[12] In the thermosetting process, a chemical reaction occurs that is
irreversible. The vulcanization of rubber is an example of a thermosetting process: before heating
with sulfur, the polyisoprene is a tacky, slightly runny material; after vulcanization, the product is rigid
and non-tacky.
Amorphous plastics and crystalline plastics

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Plastics are a wide range of synthetic or semi-synthetic organic compounds that are malleable and

so can be molded into solid objects.

Properties and classifications

Thermoplastics and thermosetting polymers

The plastic handle of a spatula that has been deformed by heat.

Amorphous plastics and crystalline plastics

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