Free radical addition polymerization of Polyethylene (polyethene)

Conditions: 200 MPa and above 160 degrees Celsius• Monomer: Ethene• Initiator: benzoyl peroxide• Summary of process: The initiator breaks apart and

forms radicals. The radicals attatch to ethene molecules and breaks the pi bond in ethene. This is called initiation. An unpair electron is now present at the end of the chain to continue the process, lengthening the molecule. This is called propagation. If two radicals bond together there will be no more unpaired electrons. This stops the propagation of the chain and is called termination.

The blue molecule represents a benzoyl ring

Initiation

Propagation

Termination