Question
How does the presence of benzoquinone inhibit the free radical polymerization of a vinyl derivative?
Solution
In the free radical polymerization of vinyl derivative, a reactive intermediate (R*) is formed which is responsible for the further progress of the chain reaction. Benzoquinone traps this reactive intermediate radical and changes it into non-reactive radical by stabilising it through resonance. In the absence of this reactive intermediate, further progress of the chain reaction is stopped.
