Other reactants required are oxygen from air and small amounts of a radical initiator.

Here the active site formed by a radical initiator reacts with oxygen to form a hydroperoxyl.

It is initiated with UV light or some other radical initiator.

The use of radical initiators or other chemicals can lead to the opposite product result, but the reactive-intermediate structures and mechanisms are different.

In its anti-knocking capacity, its purpose is that of a radical initiator.

Another possibility is a free-radical process, if radical initiators are present in the reaction mixture.

Owing to this process, some aliphatic azo compounds are utilized as radical initiators.

Most benzoyl peroxide is used as a radical initiator to induce polymerizations.

After the radical initiator is formed, it attacks a monomer (Figure 11).

Figure 12 shows how the orbitals of an ethylene monomer interact with a radical initiator.