Making Polymerstodhigh.com/.../uploads/2018/03/Making-Polymers.pdfMaking Polymers Author Boardworks...
Transcript of Making Polymerstodhigh.com/.../uploads/2018/03/Making-Polymers.pdfMaking Polymers Author Boardworks...
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Making Polymers
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The word ‘polymer’ comes from the Greek words
poly (meaning ‘many’) and meros (meaning ‘parts’).
Polymers are very large molecules made when hundreds
of monomers join together to form long chains.
Plastics are synthetic polymers that
can be shaped by heat or pressure.
What are polymers?
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The materials that are used in every day life are made of
either pure chemicals (elements or compounds) or
mixtures of chemicals.
Where do materials come from?
Although pure metals are
sometimes used in the manufacture
of products, often mixtures of more
than one metal are used as they
have more useful properties.
Polymers are manufactured as pure compounds.
However, other compounds are often added,
which improve the properties of the plastic, for
example, to make it more flexible.
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Natural and synthetic materials
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Materials from living things
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Natural and synthetic polymers
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Polymerization is the reaction used to convert monomers
into polymers. The monomers in a polymer are joined
together by covalent bonds between atoms.
In a covalent bond, each atom shares one or more electrons
with another atom. The bonds are sometimes shown as lines.
What keeps the chain together?
covalent
bond
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How are monomers turned into polymers?
Making polymers
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Many polymers are formed from alkenes, which are a family
of hydrocarbon molecules with the general formula CnH2n.
Alkenes contain at least one double covalent bond between
carbon atoms. The double bond makes them very reactive.
What are polymers made from?
The simplest alkene is
ethene (C2H4).
The second simplest
alkene is propene (C3H6).
double
covalent
bond
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How is polyethene made?
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Addition polymerization
The process by which alkenes are joined together is called
addition polymerization. All of the atoms in the alkene end
up in the polymer so no other products are formed.
addition polymerizationmonomers
polymer
Addition polymerization involves the reaction of many
unsaturated monomers (which contain a carbon-carbon
double bond) to form a saturated polymer.
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Drawing polymers – shorthand formulae
Polymers contain thousands of molecules, so how can their
structures be easily drawn?
Part of the polymer molecule can be drawn:
A better way is to show a shorthand formula:
The ‘n’ means that the polymer
contains a very large number of the
repeating unit shown in the brackets.
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What’s the polymer?
What is the shorthand formula for polypropene?
The monomer is
propene (C3H6):
which can
be drawn as:
1. Draw two C atoms that were in
the double bond with a single
covalent bond.
2. Draw the brackets and the ‘n’.
4. Add the atoms that were attached
to each C atom of the double bond.
3. Add the links outside the brackets.
polypropene
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Naming polymers
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Which polymer?
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What’s the monomer?
What is the monomer of
polyvinylchloride (PVC)?
1. Draw two C atoms joined with a
double covalent bond.
2. Add the atoms attached to each
C atom.
3. Draw the brackets and ‘n’.
The equation for
the reaction can
be drawn as:
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Which monomer?
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Glossary
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Multiple-choice quiz