Question

Which of the following are polycarbamate ester polymers?

• A. Polyurethane
• B. Perlon-U
• C. Melamine
• D. Saran

Answer 1

Answer: (A), (B)

The correct options are
A Polyurethane
B Perlon-U

Polyurethane (PUR and PU) is a polymer composed of a chain of organic units joined by carbamate (urethane) links. Polyurethanes are produced by reacting an isocyanate containing two or more isocyanate groups per molecule $(R-(N=C=O{)}_{n2})$ with a polyol containing on average two or more hydroxy groups per molecule $(R^{\prime }-(OH{)}_{n2})$ in the presence of a catalyst or by activation with ultraviolet light.
It contains an ester link.

Perlon-U is a trade name for polyurethane fibre based on the reaction of hexamethylene diisocyanate with $1,4$ - butanediol, i.e, the $6,4$ - polyurethane.
Melamine is an organic base and a trimer of cyanamide, with a $1,3,5$ - triazine skeleton. No ester link is present.