Addition polymer

An Addition Polymer is a polymer which is formed by an addition reaction, where many monomers have bonded together via rearrangement of bonds without the loss of any atom or molecule. This is in contrast to a Condensation polymer which is formed by a condensation reaction where a molecule, usually water, is lost during the formation. Addition polymers are widely used today in the form of plastic. This includes Polythene (Polyethene) and PVC.

With the exception of combustion, Addition polymers are generally chemically inert. This is due to the very strong C-C and C-H bonds and lack of polarisation within many addition polymers. For this reason they are non-biodegradable and hard to recycle. This is, again, in contrast to condensation polymers which are bio-degradable and can be recycled.

The first useful addition polymer was made by accident in 1933 by ICI chemists Reginald Gibson and Eric Fawcett. They were carrying out a series of experiments which involved reacting organic compounds under high temperatures and high pressures. They set up an experiment to react ethene with benzaldehyde in the hope of producing a ketone. They left the reaction vessel overnight and when they looked in it in the morning they found a small amount of a white waxy solid. It was shown later that this solid was polyethene.