Depict a free radical mode of addition polymerisation in isoprene.

Explanation

Free radical polymerisation in isoprene is initiated by a free radical attack.
`underset(("Free radical"))(R^(.) + )CH_(2) = underset(CH_(3))underset(|)(C) - CH = CH_(2) rarr R - CH_(2) - underset(("Free radical"))underset(CH_(3))underset(|)(C) = CH - CH_(2)`
Free radicals participate in further polymerisation. For details, consult section 2