The given question asks for the monomer of Novolac. Novolac is one of the most common types of phenolic resins, which are important synthetic polymers. To determine the correct monomer, we must understand how Novolac is formed.
The polymerization process of Novolac involves the condensation reaction between phenol and formaldehyde under acidic conditions. The initial product of this reaction is ortho- and para-Hydroxymethylphenols, which further polymerize to form Novolac.
Let's evaluate the given options:
o-Hydroxymethylphenol: This is indeed a key intermediate monomer in the formation of Novolac. It is formed through the reaction of phenol with formaldehyde.
Phenol and melamine: These are different compounds used in different types of resins. Melamine is used with formaldehyde to create melamine resins, not Novolac.
1,3-Butadiene and styrene: These are used in the production of synthetic rubbers, such as styrene-butadiene rubber (SBR), not in Novolac.
3-Hydroxybutanoic acid: This is not related to phenolic resins and is not involved in the production of Novolac.
Based on these evaluations, the correct answer is o-Hydroxymethylphenol, as it directly relates to the formation of Novolac through the polymerization of phenol with formaldehyde.
