A+B → Nylon 6, 6

Predict A and B:

Hexamethylene diamine + adipic acid

The correct answer is Option 4. Hexamethylene diamine + adipic acid.

Nylon 66 is synthesized by polycondensation of hexamethylenediamine and adipic acid. Equivalent amounts of hexamethylenediamine and adipic acid are combined in water. In the original implementation, the resulting ammonium/carboxylate salt was isolated and then heated either in batches or continuously to induce polycondensation