Types of Polymers and reactions
Formations and linkages
What are polymers?
• Alkene molecules have the ability to add onto
one another and produce large molecules
these are polymers.
• Therefore what are monomers?
• The process of these large molecules forming
is termed addition polymerisation.
• NOTE POLYMERISATION IS NOT RESTRICTED
TO CARBON-CARBON DOUBLE BOND
COMPOUNDS.
TYPES
• Condensation polymers eg. Polyester,
polyamides, proteins
• Polysaccharides
• Disaccharides
• Monosaccharide
Condensation Polymers
• This is the process where molecules that have
functional groups either end undergo a
condensation reaction with another molecule
and its functional group and as a result a ester
is formed. The process condensation
polymerisation and the polymer is
condensation polymer.
Polyesters
• Please explain how polyesters are formed and
give a example, make sure you use
appropriate terminology in your explanation.
(time limit 8-10min)
Polyamides
• Are condensation polymers where monomers
join by amide links these are similar to
polyesters in that they can form
homopolymers and copolymers.
• What is meant by homopolymers and
copolymers? And what is the difference
between functional groups in these polymers?
Proteins
• Proteins are high molecular mass copolymers
made from condensation polymerisation
between amino acids monomers.
• There are 20 different monomers proteins can
be constructed from so these make up a large
number of proteins.
• What are the four structural features in
proteins that the amino acids have in
common?
The protein polymer
• To form peptide linkages two amino acids link together.
One alpha amino acid reacts its NH₂ group with the other
amino acids COOH group forming the link CO-NH.
• If we have a smaller number of monomers linked together
than having a complete protein we call these polypeptides.
Obviously if we have two monomers linked together this is
called a dipeptide.
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Summary of peptide linkage
Formation of the peptide bond
O
O
R1
R2
OH
OH
NH2
NH2
O
The molecules must be
orientated so that the
carboxylic acid group of one
can react with the amine group
of the other
R2
R1
OH
H2N
O
NH2
Two amino acid molecules;
the nature of the R group (R1
and R2) determines the amino
acid
HO
O
R2
R1
H2O
NH
O
NH2
HO
The peptide bond forms with
the elimination of a water
molecule; it is another
example of a condensation
reaction
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Polysaccharides
• Or known as carbohydrates/sugars, the
simplest form of these are monosaccharides if
we have two of these sugars bonded together
these are disaccharides.
• Oligosaccharides are when we have 3 up to 10
mono’s per molecule
• Polysaccharides is when we have 10 to
thousands of mono’s
Monosaccharides
• These are linked together by a C-O-C known
as a ether linkage or glycosidic bond.
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• Also please refer to page 230 figure 7.45
Polysaccharides
• The three main polysaccharides that you will
need to know are glycogen, starch and
cellulose.
• These each differ from each other in relation
to their ether linkages the amount of branches
in their polymer chains and the degree of
polymeristion.
Fractional distillation
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• Read pages 233-235
• Pre-treatment
• Atmospheric distillation
• Vacuum distillation
• cracking
Questions
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Ex 7.4 all
Ex 7.5 Q3,4,5,6
Ex 7.6 Q1,3
Review Q5,6