In polymer and fibre technology, “Dacron” (also marketed as Terylene) refers to which material class used for strong, wrinkle-resistant synthetic fibres?

Introduction / Context:
Dacron is a widely used trade name in fibre science and textile engineering. Understanding what Dacron chemically represents helps learners connect trade names with polymer classes, processing behavior, and end-use properties such as strength, wrinkle resistance, and chemical durability.

Given Data / Assumptions:

• Dacron is a trade/brand name used historically for a common synthetic fibre.
• It is produced by polycondensation of a diacid (or its ester) with a diol.
• The fibre is known for toughness, crease resistance, and good acid resistance.

Concept / Approach:

Dacron is polyethylene terephthalate (PET), which belongs to the polyester family. It is typically made via transesterification of dimethyl terephthalate with ethylene glycol followed by polycondensation, or directly from terephthalic acid and ethylene glycol. The repeating ester linkage (-CO-O-) classifies it as a polyester, not a polyamide (e.g., nylon) or inorganic polymer (e.g., polysiloxanes with inorganic backbones).

Step-by-Step Solution:

Verification / Alternative check:

Textile and polymer handbooks list Dacron/Terylene as PET, a linear thermoplastic polyester used for fibres, films, and bottles, confirming its classification as a polyester.

Why Other Options Are Wrong:

Unsaturated polyester: Typically used in resins for composites; Dacron is a saturated thermoplastic polyester (PET). Polyamide: Refers to nylons (amide linkages), not ester linkages. Inorganic polymer: PET is organic, not an inorganic backbone polymer.

Common Pitfalls:

Confusing trade names (Dacron, Terylene) with resin types like unsaturated polyester; assuming all synthetic fibres are nylons.

Final Answer:

Polyester