Question:
Monomer of Novolac is :
Monomer of Novolac is :
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Novolac is the linear resin, while Bakelite is the cross-linked version. Both are made from phenol and formaldehyde.
Updated On: Jan 2, 2026
- \(o\)-Hydroxymethylphenol.
- phenol and melamine.
- 1,3-Butadiene and styrene.
- 3-Hydroxybutanoic acid.
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The Correct Option is A
Solution and Explanation
Step 1: Understanding the Concept:
Novolac is a linear polymer of phenol and formaldehyde formed under acidic conditions. It is the precursor to Bakelite.
Step 2: Detailed Explanation:
The reaction between phenol and formaldehyde (\(\text{HCHO}\)) in the presence of an acid or base catalyst starts with the initial formation of \(o\)- and/or \(p\)-hydroxymethylphenol derivatives.
In the case of Novolac (acid-catalyzed, excess phenol), the \(o\)-hydroxymethylphenol (also known as salicyl alcohol) molecules undergo condensation to form a linear chain.
Therefore, \(o\)-hydroxymethylphenol is considered the primary monomer/intermediate unit for the linear Novolac resin.
Step 3: Final Answer:
Among the given options, \(o\)-hydroxymethylphenol is the correct choice. Option (B) relates to melamine-formaldehyde, (C) to Buna-S, and (D) to PHBV.
Novolac is a linear polymer of phenol and formaldehyde formed under acidic conditions. It is the precursor to Bakelite.
Step 2: Detailed Explanation:
The reaction between phenol and formaldehyde (\(\text{HCHO}\)) in the presence of an acid or base catalyst starts with the initial formation of \(o\)- and/or \(p\)-hydroxymethylphenol derivatives.
In the case of Novolac (acid-catalyzed, excess phenol), the \(o\)-hydroxymethylphenol (also known as salicyl alcohol) molecules undergo condensation to form a linear chain.
Therefore, \(o\)-hydroxymethylphenol is considered the primary monomer/intermediate unit for the linear Novolac resin.
Step 3: Final Answer:
Among the given options, \(o\)-hydroxymethylphenol is the correct choice. Option (B) relates to melamine-formaldehyde, (C) to Buna-S, and (D) to PHBV.
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