# Which is used for the formation of Nylon-66?

$\begin {array} {1 1} (a)\; Sulphur\: hexafluoride & \quad (b)\; Adipic \: acid \\ (c)\; Sulphurous\: acid & \quad (d)\; Phtalic\: acid \end {array}$

Nylon is a generic name for a synthetic linear polymer with repeating amide groups $(-NH-CO- )$ which is used in the manufacture of textile fibres. Carothers produced Nylon 66 by condensation reaction of adipic acid (a dicarboxylic acid with 6 carbon atoms) and hexamethylenediamine (a diamine with 6 carbon atoms) give the $[-NH-(CH_2)_6-NH-CO(CH_2)_4-CO-]$ repeating unit. Nylon revolutionised the textile industry and was the forerunner for many of today's modern, synthetic fabrics.
Ans : (b)