Identify the copolymer among the following polymer examples.

Introduction / Context:
A copolymer consists of two or more different monomer species incorporated in the same polymer chain. Recognising copolymers helps anticipate property tuning via composition and sequence control.

Given Data / Assumptions:

• Nylon-66 forms from hexamethylene diamine and adipic acid.
• Polypropylene, PVC, PTFE, and PMMA listed here are homopolymers of a single repeating monomer unit.

Concept / Approach:
Nylon-66 is an alternating condensation copolymer because its repeat unit derives from two distinct monomers (a diamine and a diacid). In contrast, polypropylene (from propylene), PVC (from vinyl chloride), PTFE (from tetrafluoroethylene), and PMMA (from methyl methacrylate) are homopolymers in their standard commercial forms.

Step-by-Step Solution:
Define copolymer vs homopolymer.Match each example to its monomer set.Select nylon-66 as the copolymer in the list.

Verification / Alternative check:
Polymer naming conventions for nylons reflect the carbon counts of the two monomers (6,6), indicating two-monomer chemistry.

Why Other Options Are Wrong:
PP, PVC, PTFE, PMMA are classically single-monomer polymers in their basic grades.

Common Pitfalls:
Assuming “condensation polymer” implies homopolymer; overlooking that many step-growth polymers are copolymers by nature.

Final Answer:
Nylon-66