What is the name of the polymer?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Terylene
The repeating unit –\( \ce{O-CH2-CH2-O-CO-C6H4-CO} \)– contains ester linkages, so the polymer is a polyester. It is made by condensation of ethylene glycol (ethane-1,2-diol) with terephthalic acid (benzene-1,4-dicarboxylic acid); this polyester is terylene (Dacron).
\( \ce{nHOCH2CH2OH + nHOOC-C6H4-COOH} \xrightarrow{\text{420-460 K}} \ce{[-OCH2CH2O-CO-C6H4-CO-]_n + 2nH2O} \)
Why the other options are incorrect
Option (1) Teflon — Incorrect. Polytetrafluoroethene, –(CF2–CF2)n–, an addition polymer with no oxygen in the chain.
Option (2) Nylon 6 — Incorrect. A polyamide, –[NH–(CH2)5–CO]n–, made from caprolactam; it has amide, not ester, links.
Option (4) Polyacrylonitrile — Incorrect. –(CH2–CH(CN))n–, an addition polymer of acrylonitrile (orlon, acrilan).
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Polyesters
