Step 1: Understanding the Concept:
Nylon-6,6 is a polyamide made from a diamine and a dicarboxylic acid, each containing 6 carbon atoms.
Step 2: Detailed Explanation:
Nylon-6,6 is synthesized by the condensation polymerization of hexamethylenediamine (H\(_2\)N-(CH\(_2\))\(_6\)-NH\(_2\)) and adipic acid (hexanedioic acid, HOOC-(CH\(_2\))\(_4\)-COOH). The "6,6" refers to the six carbon atoms in each monomer.
Step 3: Final Answer:
Hexanedioic acid (adipic acid) is used in the manufacture of nylon-6,6.