Nylon-6 feedstock — Caprolactam, the monomer used to make nylon-6, is industrially produced starting from which primary aromatic feedstock?
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APhenol
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BNaphthalene
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CBenzene (via cyclohexanone/oxime route)
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DPyridine
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EToluene
Answer
Correct Answer: Benzene (via cyclohexanone/oxime route)
Explanation
Introduction / Context:Nylon-6 is a major engineering and textile polymer produced by ring-opening polymerization of caprolactam. Understanding the upstream petrochemical pathway is core chemical technology knowledge.
Given Data / Assumptions:
- We are selecting the principal industrial route to caprolactam.
- Modern routes commonly begin with benzene.
Concept / Approach:Industrial synthesis typically proceeds: benzene → cyclohexane → cyclohexanone (or cyclohexanone oxime) → caprolactam (via Beckmann rearrangement). Alternative routes have existed historically, but benzene-based routes dominate due to availability and economics.
Step-by-Step Solution:Identify mainstream feed: benzene.Hydrogenate/oxidize sequence → cyclohexanone.Convert to oxime; Beckmann rearrangement → caprolactam.
Verification / Alternative check:Process economics and global capacity reports confirm benzene-based routes as the principal industrial method.
Why Other Options Are Wrong:
- Phenol and toluene: used in other syntheses; not the dominant caprolactam starting points today.
- Naphthalene, pyridine: not standard modern routes for caprolactam production.
Common Pitfalls:Confusing nylon-6 (caprolactam) with nylon-6,6 (adipic acid + hexamethylenediamine) feedstocks.
Final Answer:Benzene (via cyclohexanone/oxime route)