Name the polymer formed from hexamethylene diamine and adipic acid.

Introduction / Context:
Condensation polymerisation of diamines and diacids yields polyamides whose numeric designations reflect monomer carbon counts. Correctly pairing monomers to nylon designations is a frequent materials question.

Given Data / Assumptions:

• Hexamethylene diamine has 6 carbons.
• Adipic acid also has 6 carbons.
• Polymer naming convention: nylon-x,y where x and y are carbon counts.

Concept / Approach:
Nylon-66 results from 6-carbon diamine and 6-carbon diacid. Nylon-6 would arise from a single 6-carbon monomer (caprolactam). Nylon-6,10 uses a 6-carbon diamine and a 10-carbon diacid (sebacic).

Step-by-Step Solution:
Identify monomers: 6 + 6 carbons.Apply naming convention → nylon-66.Select nylon-66 from the options.

Verification / Alternative check:
Standard polymer handbooks confirm nylon-66 composition and properties.

Why Other Options Are Wrong:
Nylon-6: from caprolactam, not a diamine/diacid pair.Nylon-6,10: requires sebacic acid (10 carbons), not adipic acid.Epoxy/ PET: different polymer families and monomers.

Common Pitfalls:
Confusing the numeric code (6,6 vs 6; 6,10) and their monomer sources.

Final Answer:
Nylon-66