Identify the polymer produced from terephthalic acid and ethylene glycol in polyester chemistry.

Introduction / Context:Matching monomers to their resultant polymers is a frequent exam task. Here, the diacid–diol pair points to a condensation polyester used extensively in fibres and bottles.

Given Data / Assumptions:

• Terephthalic acid (or dimethyl terephthalate) and ethylene glycol are the monomers.
• We assume standard melt polycondensation.
• Trade name “terylene” is commonly used for PET fibres.

Concept / Approach:Condensation of terephthalic acid with ethylene glycol forms polyethylene terephthalate (PET), known as terylene in fibre applications. Nylon-66 is a polyamide (diamine + diacid), PVC is an addition polymer from vinyl chloride, and polystyrene is from styrene; none match the given monomers.

Step-by-Step Solution:Map monomers: terephthalic acid + ethylene glycol → PET.Relate PET to the trade name “terylene”.Eliminate other options due to mismatched monomers.

Verification / Alternative check:Polyester process flowsheets show esterification/transesterification followed by polycondensation giving PET chips for fibre and bottle-grade resin.

Why Other Options Are Wrong:Nylon-66 uses hexamethylene diamine + adipic acid.PVC and polystyrene are addition polymers of vinyl chloride and styrene, respectively.

Common Pitfalls:Confusing “nylon” (polyamide) with “polyester” due to similar applications in fibres.

Final Answer:Terylene (polyethylene terephthalate, PET)