Download Unit C Lesson 10 Polymers

Polymers

A polymer is a very long molecule that is made by linking together many smaller,
repeating units known as monomers (similar to paper clips linked into a chain).

Some polymers contain only one type of repeating unit, while others are made up of
two or more types. The type(s) involved determines the properties of the polymer.

Plastics are synthetic polymers that can be heated and moulded into specific shapes.

The name of a polymer often involves the common name of the monomer, rather than
the proper IUPAC name. The prefix poly- is included.
Monomer
Structure
IUPAC Name
of Monomer
Common Name
of Monomer
CH2 = CH2
ethene
ethylene
polyethylene (used in
plastic bags)
CH = CH2
chloroethene
vinyl chloride
polyvinylchloride
(PVC, used to insulate
electric wiring)
propene
propylene
polypropylene (used in
ropes and carpet)
Cl
CH3 – CH = CH2
Polymer Name
Addition Polymerization

Alkene monomers can be linked together through multiple addition reactions to form
a polymer.

The electrons of the double bond are rearranged. The polymer is the only product
formed.

EX. The formation of polyethylene
H H
H H
H H
HH
HH
H H
HH HHHH
C=C + C=C + C=C  C-C + C-C + C-C  C-C-C-C-C-C
H H
H H
H H
HH
ethylene monomers
(ethene)

Examples of Addition Polymers
HH
H H
HH HHHH
polyethylene
Condensation Polymerization

Monomers are combined through multiple condensation reactions.

A second smaller product, usually water, is also produced.

Each monomer must have two functional groups, usually one at each end ot the
molecule.

Polyesters are a polymer made through an esterification reaction. To allow for
multiple linkages, the carboxylic acid must contain at least two carboxyl groups and
the alcohol must contain at least two hydroxyl groups.

EX. The formation of polyethylene terephthalate (PET) which is used to make softdrink and water bottles.

Polyamides are another type of condensation polymer. These are important in living
organisms as the basis for the formation of proteins. The monomers have an amino
group (-NH2) at one end of the molecule and a carboxyl group (-COOH) at the other
end. In proteins, the amide linkage is called a peptide bond.

Examples of Condensation Polymers
Chem 30
Polymerization Reactions
1. Draw the product of each polymerization reaction and classify the reaction:
2. Draw the monomers in each polymerization reaction: