Polymer Chemistry — Trade Names and Structures Which of the following materials is commonly called a “polyamide”?

Introduction / Context:
Synthetic fibers are often identified by both trade names and polymer classes. A polyamide is a polymer with repeating amide (–CONH–) linkages in the backbone. Recognizing which common textile corresponds to which polymer family is a frequent exam requirement in materials science and everyday science sections.

Given Data / Assumptions:

• Options include widely used fibers: Terylene, Nylon, Rayon, Orlon.
• We match each to its polymer class.
• We use standard commercial names and textbook classifications.

Concept / Approach:
Nylon (e.g., Nylon-6,6 or Nylon-6) is the classic polyamide, formed via condensation of diamines and dicarboxylic acids (or by ring-opening polymerization in Nylon-6). Terylene is polyethylene terephthalate (PET), a polyester. Rayon is regenerated cellulose (semisynthetic), not a condensation synthetic polymer class. Orlon is polyacrylonitrile (PAN), an acrylic fiber.

Step-by-Step Solution:

Verification / Alternative check:
Textile labeling and polymer handbooks list Nylon under the polyamide family, confirming the match.

Why Other Options Are Wrong:

• Terylene: Polyester, not polyamide.
• Rayon: Regenerated cellulose.
• Orlon: Polyacrylonitrile (acrylic fiber).

Common Pitfalls:
Confusing trade names across polymer families. Memorize representative examples: Nylon (polyamide), Terylene (polyester), Orlon (acrylic), Rayon (cellulose-based).

Final Answer:
Nylon