The [chemical] process by which [one or more] monomer(s) becomes a polymer





Addition Polymerisation
a polymer chain grows by addition of monomer to a reactive end-group



Condensation polymerisation
A polymer chain grows step-wise by reaction that involve the elimination of a small molecule

A homopolymer is a polymer, which is made from only one monomer. We can also say it is a chain made up of identical repeat units, like polyethylene is made up of ethylene repeat units. For example, for a monomer called A:

n = the number of repeat units in the chain.
Naming Polymers
In order to name the polymer
- The prefix “poly” is added to the name of the monomer, which is placed in brackets if there is more than one word.
Monomer X ———> Poly X
E.g.
Styrene X ———> Polystyrene X
Ethylene X ———> Polyethylene X
Ethylene glycol X ———> Poly(ethylene glycol) X

are called vinyl monomers and vinyl is included in the polymer name.


The naming of specific polymers will be discussed further in the following chapters.
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Polymer
The word polymer is derived from two words in Greek: poly ( meaning many ) and meros ( meaning parts ). A polymer is a substance composed of molecules with a large molecular weight formed from many repeating units, usually covalently bonded together.

Because of thir high molecular weight polymer molecules are also called macromolecules. Examples of polymers are polystyrene, polyethylene, and poly vinyl chloride ( PVC ). The long chin nature of polymers gives them special properties.
Monomer
The word monomer is from the Greek word “mono” ( meaning alone ). A monomer is a simple molecular unit which when it is reached with other monomers forms a polymer. Examples of monomers are styrene, ethylene or vinyl chloride.
Polymerization
Polymerization is the process of forming of a polymer by linking monomers together by chemical reaction. For example polymerization of rthylene yields polyethylene, a typical sample of which may contain molecules with 50,000 carbon atoms linked together in a chain.
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