Formation of addition and condensation polymers

Revision notes on the formation and addition and condensation polymers for unit 4.

Includes notes about the problems with disposing of polymers

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  • Created on: 17-10-11 13:38
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Becca
Polymers
There are two types of polymers, addition and condensation polymers
Addition polymers
Addition polymers are where multiple monomers are added together to form a long chain molecule
of repeating units. They are made by breaking the double bond in alkenes to allow them to join
together. Conditions needed are usually heat, pressure and a catalyst.
There are different types of addition polymers as the monomers can join in different ways.
Asymmetrical polymers can form different structures. These are:
Atactic random facing monomers
o Irregular structure, little crystallinity, very soft and flexible
o Used as sealants to prevent water entry
Isotactic all monomers are the same way facing
o Regular structure, rigid, crystalline polymer and heat resistant
o Used to make carrier bags, food containers and medical equipment that needs to be
sterilised with heat.
Syndiotactic methyl groups in alternating direction
o Regular structure, rigid, heat resistant and crystalline polymer
o Used to make medical tubing
Propene can be polymerised by Ziegler-Natta catalysts to produce
stereoregular polymers. The two types of stereoregular polymers
are syndiotactic and isotactic. Stereoregular polymers have regular structures which results in
the chains packing together closely. This results in strong intermolecular forces which are
stronger than those in atactic polymers. The structure in atactic polymers is random, which
results in chains being less closely packed together and weaker and reduced intermolecular
forces, as there are less points of interaction. Atactic polymers commonly are flexible, soft
and have low boiling and melting points.
Condensation polymers
Condensation polymers are where there are usually two different monomers joined together whilst
removing a small molecule like water or HCl.

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The monomers usually have an alcohol, carboxylic acid or an amine functional group on each end of
the molecule.
Requires a catalyst e.g. antimony(iii) oxide at 280 degrees Celsius.
There are two types of condensation polymers, polyesters and polyamides.
In polyester the monomers are joined together by ester links. An example of polyester is terylene.
Ester link
In polyamides the monomers are joined together by amide links or peptide bonds. Examples of a
polyamide are nylon and Kevlar.…read more

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which loses a hydrogen, then bonds with the carbon atom which has lost a chlorine.
This produces the polymer.
Nylon 6,6 is made from 1,6- diamino hexane and hexane 1,6- dicarboxylic acid.
o By product is water
o Repeat unit in abbreviated version
Kevlar is used in bullet proof vests, sports racquets and fire retardant clothing
o It is made from benzene 1,4- diamino and benzene 1,4- dicarboxylic acid.…read more

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