GCSE SCIENCE CHEMISTRY HIGH SCHOOL - Polymerisation of Ethene - Repeat Unit - Addition Polymer - Poly(propene) - Poly(chloroethene) - PVC - Poly(tetrafluoroethene) - PTFE - Poly(phenylethene) - PVC

Polymerisation of Ethene - Chemistry.

Polymerisation of Ethene

Ethene put under pressure and heated with a catalyst
will polymerise (make long chains of atoms) to form poly(ethene).
Note that there are no double bonds in the polymer.
Poly(ethene) is an alkane. It is a saturated hydrocarbon.

Depending on the reaction conditions and the type of catalyst used,
ethene can make either HDPE or LDPE.
HDPE is High Density Poly(Ethene) and has a higher crystallinity
and a higher melting point than LDPE (Low Density Poly(Ethene).
HDPE is stronger and stiffer than LDPE.

A polymer which is formed from monomers added together
where no other substance is produced is called an addition polymer.

Examples of addition polymers are
poly(ethene), poly(propene), poly(tetrafluoroethene) - PTFE,
poly(chloroethene) - PVC and poly(phenylethene) - polystyrene.

Chloroethene used to be called vinyl chloride.
The polymer is still called polyvinyl chloride, or PVC.

Phenylethene used to be called styrene.
The polymer is still called polystyrene.

A polymer is often written in the form

Polymer Repeat Unit
The brackets contain the repeat unit.
The small n means that there are many of them.

Below are some examples of the repeat units of polymers.

See properties and uses of polymers.

Headings Polymers Search Questions

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