Answer:
Phenol reacts with formaldehyde to form Phenol-formaldehyde resins which is used to make plastic bakelite. Phenol-formaldehyde resins are made through a step-growth polymerization reaction.
equation of polymerization reaction in which Phenol (HOC6H5) reacts with formaldehyde (CH2O) is as following:
1. HOC6H5 + CH2O => HOC6H4CH2OH (hydroxymethyl phenol)
hydroxymethyl phenol then reacts with another hydroxymethyl group in next two steps and form methylene bridge (at firs) and ether bridge (secondly)
2. HOC6H4CH2OH + HOC6H5 => (HOC6H4)2CH2 + H2O
3. 2 HOC6H4CH2OH => (HOC6H4CH2)2O (bisphenol F) + H2O
Bisphenol F is the the diphenol (HOC6H4)2CH2 that is formed as the result and used to produce epoxy resins.