Q.Which of the following is a polyamide?

Nylon-6,6 is formed by amide (peptide-like) linkages between a diamine and a diacid, making it a polyamide.

Nylon-6,6 is a condensation polymer made from hexamethylenediamine (a 6-carbon diamine) and adipic acid (a 6-carbon dicarboxylic acid), which react by repeated amide-bond formation (with loss of water):

$nH_2N(CH_2)_6NH_2 + n\,HOOC(CH_2)_4COOH \rightarrow [-NH(CH_2)_6NH-CO(CH_2)_4CO-]_n + 2n\,H_2O$

Because the repeat unit is joined through -CO-NH- (amide) linkages, it is a polyamide.

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Nylon 6,6 is a polyamide — option (B).

A polyamide has repeating amide (–CO–NH–) linkages. Nylon 6,6 is made by condensation of hexamethylenediamine with adipic acid, producing chains joined by amide bonds → it is a polyamide.

• Teflon → C–F chains (no amide). …