A short fragment of a polymer chain (one repeat unit with its two end groups shown) is drawn. Which pair of monomers, shown as two molecules among the structures, gives this condensation polymer?

AStructure A
BStructure B
CStructure C
DStructure D

Answer: D

The chain contains ester links between a 1,4-benzenedicarbonyl unit and a two-carbon diol unit, so it is poly(ethylene terephthalate), PET (terylene, dacron). It forms from terephthalic acid (benzene-1,4-dicarboxylic acid) and ethylene glycol with loss of water. Phthalic acid would give the glyptal-type ortho ring, isophthalic acid a meta ring, and propane-1,3-diol a three-carbon diol unit.

Practice Polymers More on Monomer from drawn repeat unit

Previous questionNext question

More questions on Monomer from drawn repeat unit

A short fragment of a copolymer chain (three repeat units, end groups shown) is drawn. The monomers are shown as pairs of molecules among th... JEE Main level
A short fragment of the polymer chain (two repeat units, end groups shown) is drawn. Which cyclic compound, among the structures shown, is t... JEE Main level
A short fragment of the polymer chain (two repeat units, end groups shown) is drawn. Which of the structures shown is the monomer from which... JEE Main level
A short fragment of a biodegradable polyester chain (three repeat units, end groups shown) is drawn. It is formed by two different hydroxy a... JEE Advanced level
A short fragment of a copolymer chain (three repeat units, end groups shown) is drawn. It is a synthetic rubber made by free radical copolym... JEE Advanced level
A short fragment of a polymer chain (three repeat units, end groups shown) is drawn. Select all correct statements. JEE Advanced level